Patent Publication Number: US-2023156268-A1

Title: Broadcast receiving apparatus, output video information generating method, broadcast receiving method, and video recording method

Description:
CROSS REFERENCE 
     This application is a Continuation of U.S. application Ser. No. 17/685,080, filed on Mar. 2, 2022, which is a Continuation of U.S. application Ser. No. 15/750,761, filed on Feb. 6, 2018, now U.S. Pat. No. 11,272,241, issued Mar. 8, 2022, which is the U.S. National Phase under 35 U.S.C. § 371 of International Application No. PCT/JP2016/062316, filed on Apr. 19, 2016, which claims the benefit of Japanese Application No. 2015-155658, filed on Aug. 6, 2015, Japanese Application No. 2015-157285, filed on Aug. 7, 2015, Japanese Application No. 2015-157906, filed on Aug. 10, 2015, Japanese Application No. 2015-158640, filed on Aug. 11, 2015, Japanese Application No. 2015-159307, filed on Aug. 12, 2015, and Japanese Application No. 2015-159758, filed on Aug. 13, 2015, the entire contents of each are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a broadcast receiving technique, an output video information generating technique, a broadcast receiving technique, and a video recording technique. 
     BACKGROUND ART 
     One of extended functions of the digital broadcasting service is data broadcasting in which digital data is transmitted by broadcast waves to display various types of information such as weather forecasts, news, and recommended TV programs. Many types of television receivers capable of receiving data broadcasting have already been on the market, and a lot of techniques for receiving data broadcasting including the technique disclosed in Patent Document 1 listed below have been released to the public. 
     RELATED ART DOCUMENTS 
     Patent Documents 
     Patent document 1: Japanese Unexamined Patent Application Publication No. 2001-186486 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In association with the recent changes in the contents distribution environment, various functional extensions have been demanded for the television receivers. In particular, there are a lot of demands for the distribution of contents and cooperated applications using a broadband network environment such as the Internet and demands for the video contents with higher resolution and higher definition. However, no matter how the data broadcasting receiving function that the current television receiver has is utilized or extended, it is difficult to provide a high-value added television receiver capable of satisfying the above-mentioned demands. 
     It is an object of the present invention to provide a broadcast receiving apparatus capable of executing a function with a higher added value. 
     Means for Solving the Problem 
     Techniques described in claims are used as means for solving the problem described above. 
     One example is a broadcast receiving apparatus configured to receive video data of a digital broadcast program, and program-cooperation data and screen layout control information with respect to the digital broadcast program, the broadcast receiving apparatus including: a receiving unit configured to receive the video data of the digital broadcast program, the program-cooperation data, and the screen layout control information; a video generating unit configured to divide a video display region for a video to be outputted into a plurality of regions on the basis of the screen layout control information, arrange program video information and any of character information, graphic information, image information, and video information in each of the plurality of regions, and generate video information obtained by synthesizing the plurality of regions as output video information, the character information, the graphic information, the image information, and the video information being generated on the basis of the received program-cooperation data, the program video information being generated on the basis of the received video data of the digital broadcast program; a display unit configured to display the output video information; and a control unit, wherein, in a case where there is no effective screen layout control information, the control unit is configured to control the video generating unit so as not to divide the video display region and to generate the program video information as the output video information until any effective screen layout control information is obtained, and wherein, after the effective screen layout control information is obtained, the control unit is configured to control the video generating unit so as to: divide the video display region into a plurality of regions on the basis of the effective screen layout control information; arrange the program video information generated on the basis of the received video data of the digital broadcast program and any of the character information, the graphic information, and the video information generated on the basis of the received program-cooperation data in each of the plurality of regions; and generate video information obtained by synthesizing the plurality of regions as the output video information. 
     Effects of the Invention 
     It is possible to provide a broadcast receiving apparatus capable of executing a function with a higher added value by using the technique of the present invention. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         FIG.  1    is a system configuration diagram showing an example of a broadcast communication system including a broadcast receiving apparatus according to a first embodiment; 
         FIG.  2 A  is an explanatory diagram of an outline of a coded signal in an MMT; 
         FIG.  2 B  is a configuration diagram of an MPU in MMT; 
         FIG.  2 C  is a configuration diagram of an MMTP packet in the MMT; 
         FIG.  3    is a conceptual diagram of a protocol stack for a broadcasting system using the MMT; 
         FIG.  4    is a layered configuration diagram of control information used in a broadcasting system; 
         FIG.  5 A  is a list of tables used for TLV-SI of the broadcasting system; 
         FIG.  5 B  is a list of descriptors used for TLV-SI of the broadcasting system;  FIG.  6 A  is a list of messages used for MMT-SI of the broadcasting system; 
         FIG.  6 B  is a list of tables used for MMT-SI of the broadcasting system; 
         FIG.  6 C  is a list (1) of descriptors used for MMT-SI of the broadcasting system; 
         FIG.  6 D  is a list (2) of descriptors used for MMT-SI of the broadcasting system; 
         FIG.  6 E  is a diagram showing the relation between data transmission and each table in the broadcasting system;  FIG.  7 A  is a block diagram of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  7 B  is a configuration diagram of a logical plane structure of a presentation function of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  7 C  is a system configuration diagram for clock synchronization/presentation synchronization in the broadcast receiving apparatus according to the first embodiment; 
         FIG.  7 D  is a software configuration diagram of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  8    is a block diagram of a broadcast station server according to the first embodiment; 
         FIG.  9    is a block diagram of a service provider server according to the first embodiment; 
         FIG.  10 A  is a block diagram of a portable information terminal according to the first embodiment; 
         FIG.  10 B  is a software configuration diagram of the portable information terminal according to the first embodiment; 
         FIG.  11 A  is a diagram showing a data structure of an MH-TOT of the broadcasting system; 
         FIG.  11 B  is a diagram showing a format of a JST_time parameter of the broadcasting system; 
         FIG.  12    is a diagram showing a method of calculating the current date from MJD of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  13 A  is a diagram showing a configuration of an NTP format of the broadcasting system; 
         FIG.  13 B  is a diagram showing a data structure of an MPU timestamp descriptor of the broadcasting system; 
         FIG.  13 C  is a diagram showing a data structure of time information in a TMCC extension information region of the broadcasting system; 
         FIG.  14    is an operation sequence diagram at the time of channel scanning of the broadcast receiving apparatus according to the first embodiment;  FIG.  15 A  is a diagram showing a data structure of a TLV-NIT of the broadcasting system; 
         FIG.  15 B  is a diagram showing a data structure of a satellite delivery system descriptor of the broadcasting system; 
         FIG.  15 C  is a diagram showing a data structure of a service list descriptor of the broadcasting system; 
         FIG.  15 D  is a diagram showing a data structure of an AMT of the broadcasting system; 
         FIG.  16    is an operation sequence diagram at the time of channel selection of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  17    is a diagram showing a data structure of an MPT of the broadcasting system; 
         FIG.  18    is a diagram showing a data structure of an LCT of the broadcasting system; 
         FIG.  19 A  is a diagram showing an example of layout assignment to a layout number based on the LCT; 
         FIG.  19 B  is a diagram showing another example of layout assignment to a layout number based on the LCT; 
         FIG.  19 C  is a diagram showing still another example of layout assignment to a layout number based on the LCT; 
         FIG.  19 D  is a diagram showing still another example of layout assignment to a layout number based on the LCT; 
         FIG.  20 A  is an explanatory diagram of an operation of an exceptional process of screen layout control based on the LCT; 
         FIG.  20 B  is an explanatory diagram of an operation of an exceptional process of screen layout control based on the LCT; 
         FIG.  21    is a diagram showing a data structure of an MH-EIT of the broadcasting system; 
         FIG.  22 A  is a screen display diagram of an EPG screen of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  22 B  is a screen display diagram of an EPG screen of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  22 C  is a screen display diagram of an EPG screen of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  23    is a screen display diagram at the time of displaying an emergency warning broadcasting message of the broadcast receiving apparatus according to the first embodiment; 
         FIG.  24    is a block diagram of a broadcast receiving apparatus according to a second embodiment; 
         FIG.  25    is an explanatory diagram of inconsistent display of current time at the time of switching broadcasting services; 
         FIG.  26 A  is an explanatory diagram of an operation of selection control of a reference source of current time information according to the second embodiment; 
         FIG.  26 B  is an operation sequence diagram of an update process of current time information according to the second embodiment; 
         FIG.  27 A  is a screen display diagram of an EPG screen of the broadcast receiving apparatus according to the second embodiment; 
         FIG.  27 B  is a screen display diagram of an EPG screen of the broadcast receiving apparatus according to the second embodiment; 
         FIG.  28    is a structural drawing of broadcast data; 
         FIG.  29    is a structural drawing of asset data; 
         FIG.  30    is a view showing a data structure of a PA message; 
         FIG.  31    is a diagram showing a data structure of MMT_general_location_info. 
         FIG.  32    is a view showing a data structure of a PLT; 
         FIG.  33    is a view showing a meaning of a location type; 
         FIG.  34    is a view showing a data structure of an MPU presentation region specifying descriptor; 
         FIG.  35 A  is an explanatory diagram of a presenting operation according to a third embodiment; 
         FIG.  35 B  is an explanatory diagram of the presenting operation according to the third embodiment; 
         FIG.  36 A  is a view showing a data structure of an LCT expiration date descriptor; 
         FIG.  36 B  is an explanatory diagram of a data structure of a layout expiration date descriptor; 
         FIG.  36 C  is a view showing a data structure of a presentation region expiration date descriptor; 
         FIG.  37    is a view showing a data structure of a common presentation region information descriptor; 
         FIG.  38    is a view showing a meaning of full_set_flag; 
         FIG.  39    is a view showing a data structure of a duplicative presentation region specifying descriptor; 
         FIG.  40    is an explanatory diagram of a presenting operation according to the third embodiment; 
         FIG.  41    is an explanatory diagram of a presenting operation according to the third embodiment; 
         FIG.  42    is a view showing a data structure of a dependency relation descriptor; 
         FIG.  43    is an explanatory diagram of a presenting operation according to the third embodiment; 
         FIG.  44    is a view showing a data structure of a modification example of the dependency relation descriptor; 
         FIG.  45    is a view showing a meaning of dependency_type; 
         FIG.  46    is an explanatory diagram of a presenting operation according to the third embodiment; 
         FIG.  47    is an explanatory diagram of a presenting operation according to a fourth embodiment;  FIG.  48    is an explanatory diagram of a presenting operation according to the fourth embodiment; 
         FIG.  49    is a view showing a data structure of a contents control descriptor; 
         FIG.  50    is a view showing a meaning of a contents control mode; 
         FIG.  51    is an explanatory diagram of the presenting operation according to the fourth embodiment; 
         FIG.  52    is an explanatory diagram of the presenting operation according to the fourth embodiment; 
         FIG.  53    is an explanatory diagram of the presenting operation according to the fourth embodiment; 
         FIG.  54    is an explanatory diagram of the presenting operation according to the fourth embodiment; 
         FIG.  55    is a view showing a protocol stack of an MPEG2-TS method; 
         FIG.  56    is a view showing a data structure of a timestamp offset descriptor; 
         FIG.  57    is an explanatory diagram of a processing method of time information according to a fifth embodiment; 
         FIG.  58    is a view showing a data structure of an MPU timestamp descriptor; 
         FIG.  59    is a view showing a data structure of an asset presentation region specifying descriptor; and 
         FIG.  60    is a view showing s data structure of an asset timestamp descriptor. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the drawings. 
     First Embodiment 
     [System Configuration] 
       FIG.  1    is a system configuration diagram showing an example of a broadcast communication system including a broadcast receiving apparatus according to the present embodiment. The broadcast communication system of the present embodiment includes a broadcast receiving apparatus  100 , an antenna  100   a , a broadband network such as the Internet  200 , a router device  200   r , an access point  200   a , a radio tower  300   t  and a broadcast satellite (or communication satellite)  300   s  of a broadcast station, a broadcast station server  300 , a service provider server  400 , an other application server  500 , a mobile phone communication server  600 , a base station  600   b  of a mobile phone communication network, and a portable information terminal  700 . 
     The broadcast receiving apparatus  100  receives broadcast waves transmitted from the radio tower  300   t  via the broadcast satellite (or communication satellite)  300   s  and the antenna  100   a . Alternatively, the broadcast receiving apparatus  100  may receive broadcast waves transmitted from the radio tower  300   t  directly from the antenna  100   a  without passing through the broadcast satellite (or communication satellite)  300   s . In addition, the broadcast receiving apparatus  100  can be connected to the Internet  200  via the router device  200   r,  and thus can perform data transmission and reception through the communication with server devices and other communication equipment on the Internet  200 . 
     The router device  200   r  is connected to the Internet  200  through wired communication, to the broadcast receiving apparatus  100  through wired or wireless communication, and to the portable information terminal  700  through wireless communication. The wireless communication may be established by Wi-Fi (registered trademark) or the like. This allows the server devices and other communication equipment on the Internet  200 , the broadcast receiving apparatus  100 , and the portable information terminal  700  to perform data transmission and reception between one another via the router device  200   r . Note that the communication between the broadcast receiving apparatus  100  and the portable information terminal  700  may be performed as direct communication by BlueTooth (registered trademark), NFC (Near Field Communication) or the like without passing through the rooter  200   r.    
     The radio tower  300   t  is a broadcasting facility of the broadcast station and transmits broadcast waves including coded data of broadcasting programs, subtitle information, other applications, general-purpose data, and the like. The broadcast satellite (or communication satellite)  300   s  is a relay device that receives broadcast waves transmitted from the radio tower  300   t  of the broadcast station, performs frequency conversion and the like as appropriate, and then transmits the radio waves to the antenna  100   a  connected to the broadcast receiving apparatus  100 . In addition, the broadcast station has the broadcast station server  300 . The broadcast station server  300  can store metadata such as broadcasting programs (video contents, etc.) and the titles, IDs, summaries, casts, broadcasting dates and the like of the broadcasting programs, and provide the video contents and metadata to a service provider based on a contract. Note that the video contents and metadata may be provided to the service provider through an API (Application Programming Interface) in the broadcast station server  300 . 
     The service provider server  400  is a server device prepared by the service provider, and can provide various services cooperated with broadcasting programs distributed from the broadcast station. In addition, the service provider server  400  stores, manages, and distributes video contents and metadata delivered from the broadcast station server  300  and various contents, applications and the like cooperated with the broadcasting programs. In addition, the service provider server  400  further has a function of searching for deliverable contents, applications and the like and presenting a list of them in response to an inquiry from the television receiver and the like. Note that the storage, management, and distribution of the contents and metadata and those of the applications may be performed by different server devices. The broadcast station and the service provider may be the same or different from each other. A plurality of service provider servers  400  may be prepared for different services. In addition, the broadcast station server  300  may be provided with the functions of the service provider server  400 . 
     The other application server  500  is a publicly known server device that stores, manages, and distributes other general applications, operating programs, contents, data, and the like. A plurality of other application servers  500  may be provided on the Internet  200 . 
     The mobile phone communication server  600  is connected to the 
     Internet  200  and is further connected to the portable information terminal  700  via the base station  600   b . The mobile phone communication server  600  manages telephone communication (telephone call) and data transmission and reception performed by the portable information terminal  700  through the mobile phone communication network, and allows the portable information terminal  700  to perform data transmission and reception through the communication with server devices and other communication equipment on the Internet  200 . The communication between the base station  600   b  and the portable information terminal  700  may be performed by W-CDMA (Wideband Code 
     Division Multiple Access: registered trademark), GSM (Global System for Mobile Communications: registered trademark), LTE (Long Term Evolution), or other communication methods. 
     The portable information terminal  700  has a function of telephone communication (telephone call) and data transmission and reception through the mobile phone communication network and a function of wireless communication through Wi-Fi (registered trademark) or the like. The portable information terminal  700  can be connected to the Internet  200  via the router device  200   r  or the access point  200   a  or via the base station  600   b  and the mobile phone communication server  600  on the mobile phone communication network, and thus can perform data transmission and reception through the communication with server devices and other communication equipment on the Internet  200 . The access point  200   a  is connected to the internet  200  through wired communication and is further connected to the portable information terminal  700  through wireless communication. The wireless communication may be established by Wi-Fi (registered trademark) or the like. Note that the communication between the portable information terminal  700  and the broadcast receiving apparatus  100  may be performed via the access point  200   a , the Internet  200 , and the router device  200   r  or via the base station  600   b  , the mobile phone communication server  600 , the Internet  200 , and the router device  200   r.    
     [Outline of MMT Method] 
     The broadcast receiving apparatus  100  shown in  FIG.  1    is a television receiver that supports MMT (MPEG Media Transport) as a media transport method for transmitting video and audio data, in place of TS (Transport Stream) defined in the MPEG (Moving Picture Experts Group)-2 system (hereinafter, “MPEG2-TS”) mainly adopted by conventional digital broadcasting systems. The broadcast receiving apparatus  100  may be a television receiver supporting both MPEG2-TS and MMT. 
     MPEG2-TS has a characteristic of multiplexing video and audio components and the like making up a program, in a single stream together with control signals and clocks. Since the components are treated as single stream with the inclusion of clocks, MPEG2-TS is suitable for the transmission of single contents through a single transmission path with an ensured transmission quality, and thus has been adopted by many conventional digital broadcasting systems. On the other hand, because of the functional limitations of MPEG2-TS for the recent changes in the contents distribution environment including the diversification of contents, diversification of equipment using contents, diversification of transmission paths through which contents are distributed, and diversification of contents accumulation environment, MMT has been established as a new media transport method. 
       FIG.  2 A  shows an example of an outline of a coded signal in MMT of the present embodiment. As shown in  FIG.  2 A , MMT of the present embodiment has an MFU (Media Fragment Unit), an MPU (Media Processing Unit), an MMTP (MMT Protocol) payload, and an MMTP packet as elements making up the coded signal. The MFU is a format at the time of transmitting video, audio, and the like, and may be configured in units of NAL (Network Abstraction Layer) unit or access unit. The MPU may be configured of MPU metadata including information related to the overall configuration of the MPU, movie fragment metadata including information of coded media data, and sample data that is coded media data. Further, MFU can be extracted from the sample data. Further, in the case of media such as video components and audio components, presentation time and decoding time may be specified in units of MPU or access unit.  FIG.  2 B  shows an example of a configuration of the MPU. 
     The MMTP packet is configured of a header and an MMTP payload, and transmits control information of the MFU and MMT. The MMTP payload has a payload header corresponding to contents (data unit) stored in a payload section.  FIG.  2 C  shows an example of an outline of a process of making the MFU from video and audio signals, storing the MFU in the MMTP payload, and then creating the MMTP packet. In the case of a video signal that is coded using inter-frame prediction, the MPU is desirably configured in units of GOP (Group of Pictures). In addition, when the size of MFU to be transmitted is small, a single MFU may be stored in a single payload section, or a plurality of MFUs may be stored in a single payload section. In addition, when the size of MFU to be transmitted is large, a single MFU may be divided and then stored in a plurality of payload sections. In order to recover a packet loss on a transmission path, the MMTP packet may be protected by such techniques as AL-FEC (Application Layer Forward Error Correction) and ARQ (Automatic Repeat Request). 
     The broadcasting system of the present embodiment uses MPEG-H HEVC (High Efficiency Video Coding) as a video coding method, and uses MPEG-4 AAC (Advanced Audio Coding) or MPEG-4 ALS (Audio Lossless Coding) as an audio coding method. Coded data of video, audio, and the like of broadcasting programs that are coded by the methods described above is formatted into MFU or MPU, stored in an MMTP payload, encapsulated in an MMTP packet, and then transmitted in the form of an IP (Internet Protocol) packet. In addition, data contents related to broadcasting programs may also be formatted into MFU or MPU, stored in an MMTP payload, encapsulated in an MMTP packet, and then transmitted in the form of an IP packet. Four types of data contents transmission methods are prepared, which include a subtitle/caption transmission method used for data steaming synchronous with broadcasting, an application transmission method used for data transmission asynchronous with broadcasting, an event message transmission method used for synchronous/asynchronous message notification to applications operating on the television receiver, and a general-purpose data transmission method for synchronous/asynchronous transmission of other general-purpose data. 
     In the transmission of MMTP packets, UDP/IP (User Datagram Protocol/Internet Protocol) is used for the broadcast transmission path, and UDP/IP or TCP/IP (Transmission Control Protocol/Internet Protocol) is used for the communication line. Further, TLV (Type Length Value) multiplexing is used in the broadcast transmission path for efficient transmission of IP packets. Examples of protocol stack for the broadcasting system of the present embodiment are shown in  FIG.  3   . In  FIG.  3   , (A) shows an example of a protocol stack for the broadcast transmission path, and (B) shows an example of a protocol stack for the communication line. 
     The broadcasting system of the present embodiment provides a scheme for transmitting two types of control information, that is, MMT-SI (MMT-Signaling Information) and TLV-SI (TLV-Signaling Information). MMT-SI is control information indicating the configuration of a broadcasting program and the like. This control information is formatted into an MMT control message, stored in an MMTP payload, encapsulated in an MMTP packet, and then transmitted in the form of an IP packet. TLV-SI is control information related to IP packet multiplexing, and provides information for channel selection and correspondence information of IP addresses and services. 
     Further, even the broadcasting system using the MMT transmits time information in order to provide an absolute time. Note that component presentation time is indicated for each TS based on different clocks in the MPEG2-TS, while component presentation time is indicated based on the coordinated universal time (UTC) in the MMT. This scheme allows a terminal device to display components transmitted from different transmission points through different transmission paths in synchronization. IP packets conforming to an NTP (Network Time Protocol) are used for providing the UTC. 
     [Control Information of Broadcasting System Using MMT] 
     As described above, in the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment, TLV-SI related to a TLV multiplexing method for multiplexing IP packets and MMT-SI related to MMT which is a media transport method are prepared as the control information. TLV-SI provides information with which the broadcast receiving apparatus  100  demultiplexes IP packets multiplexed in the broadcast transmission path. TLV-SI is composed of a “table” and a “descriptor”. The “table” is transmitted in a section format, and the “descriptor” is placed in the “table”. MMT-SI is transmission control information indicating the information related to configuration of an MMT package and broadcasting services. MMT-SI has a three-layer structure composed of a “message” layer storing “table” and “descriptor”, a “table” layer having an element and property that indicate specific information, and a “descriptor” layer indicating more detailed information. An example of the layer structure of the control information used in the broadcasting system of the present embodiment is shown in  FIG.  4   . 
     &lt;Tables Used for TLV-SI&gt; 
       FIG.  5 A  shows a list of “tables” used for TLV-SI of the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. In the present embodiment, the following tables are used as “tables” of TLV-SI. 
     (1) TLV-NIT 
     A network information table for TLV (TLV-NIT) provides information related to the physical configuration of a TLV stream transmitted through a network and indicates the characteristics of the network. 
     (2) AMT 
     An address map table (AMT) provides a list of multicast groups of IP packets making up respective services transmitted through the network. 
     (3) Table Set by Provider 
     Other tables set uniquely by the service provider and the like may be prepared. 
     &lt;Descriptors Used for TLV-SI&gt; 
       FIG.  5 B  shows a list of “descriptors” included in TLV-SI of the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. In the present embodiment, the following descriptors are used as “descriptors” of TLV-SI. 
     (1) Service List Descriptor 
     A service list descriptor provides a list of services classified by service identifications and service types. 
     (2) Satellite Delivery System Descriptor 
     A satellite delivery system descriptor indicates physical conditions for a satellite transmission path. 
     (3) System Management Descriptor 
     A system management descriptor is used to distinguish broadcasting from non-broadcasting. 
     (4) Network Name Descriptor 
     A network name descriptor describes a network name with character codes. 
     (5) Descriptor Set by Provider 
     Other descriptors set uniquely by the service provider and the like may be prepared. 
     &lt;Messages Used for MMT-SI&gt; 
       FIG.  6 A  shows a list of “messages” used for MMT-SI of the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. In the present embodiment, the following messages are used as “messages” of MMT-SI. 
     (1) PA Message 
     A package access (PA) message is used to transmit various tables. 
     (2) M2 Section Message 
     An M2 section message is used to transmit section extension format of the MPEG-2 Systems. 
     (3) CA Message 
     A CA message is used to transmit a table for identifying a conditional access method. 
     (4) M2 Short Section Message 
     An M2 short section message is used to transmit section short format of the MPEG-2 Systems. 
     (5) Data Transmission Message 
     A data transmission message is a message storing a table related to data transmission. 
     (6) Message Set by Provider 
     Other messages set uniquely by the service provider and the like may be prepared. 
     &lt;Tables Used for MMT-SI&gt; 
       FIG.  6 B  shows a list of “tables” used for MMT-SI of the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. A table is control information having an element and property that indicate specific information. A table is stored in a message and is encapsulated in an MMTP packet to be transmitted. Note that a message that stores a table may be determined in accordance with the type of the table. In the present embodiment, the following tables are used as “tables” of MMT-SI. 
     (1) MPT 
     An MMT package table (MPT) provides package configuration information such as a list of assets and locations of assets on the network. An MPT may be stored in a PA message. 
     (2) PLT 
     A package list table (PLT) presents a list of IP data flows for transmitting PA messages of MMT packages provided as a broadcasting service, packet IDs, and IP data flows for transmitting IP services. A PLT may be stored in a PA message. 
     (3) LCT 
     A layout configuration table (LCT) is used to correlate layout information for presentation with layout numbers. An LCT may be stored in a PA message. 
     (4) ECM 
     An entertainment control message (ECM) is common information made up of program information and control information, and delivers key information for descrambling and others. An ECM may be stored in an M2 section message. 
     (5) EMM 
     An entitlement management message (EMM) is used to transmit personal information including contract information for individual subscribers and key information for decoding ECM (common information). An EMM may be stored in an M2 section message. 
     (6) CAT (MH) 
     A conditional access table (CA table (CAT)) (MH) is used to store a descriptor for identifying a conditional access method. A CAT (MH) may be stored in a CA message. 
     (7) DCM 
     A download control message (DCM) transmits key-related information including a key for decoding a transmission path code for downloading. A DCM may be stored in an M 2  section message. 
     (8) DMM 
     A download management message (DMM) transmits key-related information including a download key for decoding an encoded DCM. A DMM may be stored in an M2 section message. 
     (9) MH-EIT 
     An MH-event information table (MH-EIT) is time-series information related to events included in each service. An MH-EIT may be stored in an M2 section message. 
     (10) MH-AIT 
     An MH-application information table (MH-AIT) stores all the information related to applications and startup conditions required for applications. An MH-AIT may be stored in an M 2  section message. 
     (11) MH-BIT 
     An MH-broadcaster information table (MH-BIT) is used to provide information of broadcasters present on the network. An MH-BIT may be stored in an M2 section message. 
     (12) MH-SDTT 
     An MH-software download trigger table (MH-SDTT) is used to provide download announcement information. An MH-SDTT may be stored in an M2 section message. 
     (13) MH-SDT 
     An MH-service description table (MH-SDT) has a subtable indicating a service included in a specific TLV stream and transmits information related to a sub-channel such as a name of sub-channel and a name of a broadcaster. An MH-SDT may be stored in an M2 section message. 
     (14) MH-TOT 
     An MH-time offset table (MH-TOT) transmits JST time and date (Modified Julian Date) information. An MH-TOT may be stored in an M 2  short section message. 
     (15) MH-CDT 
     An MH-common data table (MH-CDT) is used to transmit common data, which should be stored in a non-volatile memory, in a section format to all receivers that receive the MH-CDT. An MH-CDT may be stored in an M2 section message. 
     (16) DDM Table 
     A data directory management (DDM) table provides a directory configuration of files making up an application in order to separate a file configuration of the application from a configuration for file transmission. A DDM table may be stored in a data transmission message. 
     (17) DAM Table 
     A data asset management (DAM) table provides a configuration of MPU in an asset and version information of each MPU. A DAM table may be stored in a data transmission message. 
     (18) DCC table 
     A data content configuration (DCC) table provides configuration information of files as data contents in order to achieve flexible and effective cache control. A DCC table may be stored in a data transmission message. 
     (19) EMT 
     An event message table (EMT) is used to transmit information related to an event message. An EMT may be stored in an M2 section message. 
     (20) Table Set by Provider 
     Other tables set uniquely by the service provider and the like may be provided. 
     &lt;Descriptors Used for MMT-SI&gt; 
       FIGS.  6 C and  6 D  show lists of “descriptors” included in MMT-SI of the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. A descriptor is control information that provides more detailed information, and is included in a table. Note that a table in which a descriptor is included may be determined in accordance with the type of the descriptor. In the present embodiment, the following descriptors are used as “descriptors” of MMT-SI. 
     (1) Asset Group Descriptor 
     An asset group descriptor provides a relation of an asset group and a priority in the group. An asset group descriptor may be included in the MPT. 
     (2) Event Package Descriptor 
     An event package descriptor provides a correlation between an event, which represents a program, and a package. An event package descriptor may be included in MH-EIT stored in an M2 section message to be transmitted. 
     (3) Background Color Specifying Descriptor 
     A background color specifying descriptor provides a background color of a rearmost plane in layout specification. A background color specifying descriptor may be included in LCT. 
     (4) MPU Presentation Region Specifying Descriptor 
     An MPU presentation region specifying descriptor provides a location of presentation of MPU. An MPU presentation region specifying descriptor may be included in the MPT. 
     (5) MPU Timestamp Descriptor 
     An MPU timestamp descriptor indicates the time of presentation of the first access unit in the presentation order in the MPU. An MPU timestamp descriptor may be included in the MPT. 
     (6) Dependency Relation Descriptor 
     A dependency relation descriptor provides asset IDs for assets dependent on each other. A dependency relation descriptor may be included in the MPT. 
     (7) Access Control Descriptor 
     An access control descriptor provides information for identifying the conditional access method. An access control descriptor may be included in the MPT or CAT (MH). 
     (8) Scramble Method Descriptor 
     A scramble method descriptor provides information for identifying a target to be encoded at the time of scrambling and a type of an encoding algorithm. A scramble method descriptor may be included in the MPT or CAT (MH). 
     (9) Message Authentication Method Descriptor 
     A message authentication method descriptor provides information for identifying a message authentication method when message authentication is performed. A message authentication method descriptor may be included in the MPT or CAT (MH). 
     (10) Emergency Information Descriptor (MH) 
     An emergency information descriptor (MH) is used when emergency warning broadcasting is performed. An emergency information descriptor (MH) may be included in the MPT. 
     (11) MH-MPEG-4 Audio Descriptor 
     An MH-MPEG-4 audio descriptor is used to describe basic information for specifying coding parameters of an audio stream defined in ISO/IEC 14496-3 (MPEG-4 audio). An MH-MPEG-4 audio descriptor may be included in the MPT. 
     (12) MH-MPEG-4 Audio Extension Descriptor 
     An MH-MPEG-4 audio extension descriptor is used to describe a profile, level, and specific setting to a coding method of an MPEG-4 audio stream. An MH-MPEG-4 audio extension descriptor may be included in the MPT. 
     (13) MH-HEVC Video Descriptor 
     An MH-HEVC video descriptor is used to describe basic coding parameters for a video stream (HEVC stream) defined in ITU-T Recommendation H.265 and ISO/IEC 23008-2. An MH-HEVC video descriptor may be included in the MPT. 
     (14) MH-Link Descriptor 
     An MH-link descriptor identifies a service that is provided when a viewer demands additional information related to a specific matter described in a program arrangement information system. An MH-link descriptor may be included in the MPT, MH-EIT, MH-SDT, and the like. 
     (15) MH-Event Group Descriptor 
     An MH-event group descriptor is used to indicate that a plurality of events form a group when these events are related to one another. An MH-event group descriptor may be included in MH-EIT. 
     (16) MH-Service List Descriptor 
     An MH-service list descriptor provides a list of services classified by service identifications and service types. An MH-service list descriptor may be included in MH-BIT. 
     (17) MH-Short Format Event Descriptor 
     An MH-short format event descriptor represents an event name and a short description of the event in a text format. An MH-short format event descriptor may be included in MH-EIT. 
     (18) MH-Extension Format Event Descriptor 
     An MH-extension format event descriptor is added to an MH-short format event descriptor, and provides a detailed description of an event. An MH-extension format event descriptor may be included in MH-EIT. 
     (19) Video Component Descriptor 
     A video component descriptor provides parameters and description for a video component, and is used also for expressing an elementary stream in a text format. A video component descriptor may be included in the MPT or MH-EIT. 
     (20) MH-Stream Identifying Descriptor 
     An MH-stream identifying descriptor is used to attach a label to a component stream for a service so that descriptive contents indicated by a video component descriptor in MH-EIT can be referred to with the label. An MH-stream identifying descriptor may be included in the MPT. 
     (21) MH-Content Descriptor 
     An MH-content descriptor indicates the genre of an event. An MH-content descriptor may be included in MH-EIT. 
     (22) MH-Parental Rate Descriptor 
     An MH-parental rate descriptor indicates age-based viewing restriction, and is used to extend the range of restriction based on other restriction conditions. An MH-parental rate descriptor may be included in the MPT or MH-EIT. 
     (23) MH-Audio Component Descriptor 
     An MH-audio component descriptor provides parameters for an audio elementary stream, and is used also for expressing the elementary stream in a text format. An MH-audio component descriptor may be included in the MPT or MH-EIT. 
     (24) MH-Target Area Descriptor 
     An MH-target area descriptor is used to describe a target area of a program or some streams making up the program. An MH-target area descriptor may be included in the MPT. 
     (25) MH-Series Descriptor 
     An MH-series descriptor is used to identify a series program. An MH-series descriptor may be included in MH-EIT. 
     (26) MH-SI Transmission Parameter Descriptor 
     An MH-SI transmission parameter descriptor is used to indicate SI transmission parameters. An MH-SI transmission parameter descriptor may be included in MH-BIT. 
     (27) MH-Broadcaster Name Descriptor 
     An MH-broadcaster name descriptor describes a name of a broadcaster. An MH-broadcaster name descriptor may be included in MH-BIT. 
     (28) MH-Service Descriptor 
     An MH-service descriptor expresses a name of a sub-channel and a name of a provider of the sub-channel in character code together with a service type. An MH-service descriptor may be included in MH-SDT. 
     (29) IP Data Flow Descriptor 
     An IP data flow descriptor provides information of IP data flow making up a service. An IP data flow descriptor may be included in MH-SDT. 
     (30) MH-CA Startup Descriptor 
     An MH-CA startup descriptor describes startup information for starting a CAS program on a CAS board. An MH-CA startup descriptor may be included in the MPT or CAT (CA). 
     (31) MH-Type Descriptor 
     An MH-Type descriptor indicates a type of a file transmitted by an application transmission method. An MH-Type descriptor may be included in a DAM table. 
     (32) MH-Info Descriptor 
     An MH-Info descriptor describes information related to MPU or an item. An MH-Info descriptor may be included in a DAM table. 
     (33) MH-Expire Descriptor 
     An MH-Expire descriptor describes an expiration date of an item. An MH-Expire descriptor may be included in a DAM table. 
     (34) MH-Compression Type Descriptor 
     An MH-Compression Type descriptor states that an item to be transmitted is compressed, and indicates a compression algorithm for the compression and the number of bytes of the item before the compression. An MH-Compression Type descriptor may be included in a DAM table. 
     (35) MH-Data Coding Method Descriptor 
     An MH-data coding method descriptor is used to identify a data coding method. An MH-data coding method descriptor may be included in the MPT. 
     (36) UTC-NPT Reference Descriptor 
     A UTC-NPT reference descriptor is used to transmit a relation between NPT (Normal Play Time) and UTC. A UTC-NPT reference descriptor may be included in EMT. 
     (37) Event Message Descriptor 
     An event message descriptor transmits information generally related to event messages. An event message descriptor may be included in EMT. 
     (38) MH-Local Time Offset Descriptor 
     An MH-local time offset descriptor is used to provide a given offset value to actual time (e.g., UTC+9 hours) and display time to a human system when a daylight saving time system is implemented. An MH-local time offset descriptor may be included in MH-TOT. 
     (39) MH-Component Group Descriptor 
     An MH-component group descriptor defines and identifies a combination of components in an event. An MH-component group descriptor may be included in MH-EIT. 
     (40) MH-Logo Transmission Descriptor 
     An MH-logo transmission descriptor is used to describe pointing to a character string for a simplified logo and a logo in a CDT format. An MH-logo transmission descriptor may be included in MH-SDT. 
     (41) MPU Extension Timestamp Descriptor 
     An MPU extension timestamp descriptor provides a time to decode an access unit in MPU. An MPU extension timestamp descriptor may be included in the MPT. 
     (42) MPU Download Contents Descriptor 
     An MPU download contents descriptor is used to describe property information of contents that are downloaded using MPU. An MPU download contents descriptor may be included in MH-SDTT. 
     (43) MH-Network Download Contents Descriptor 
     An MH-network download contents descriptor is used to describe property information of contents that are downloaded through the network. An MH-network download contents descriptor may be included in MH-SDTT. 
     (44) MH-Application Descriptor 
     An MH-application descriptor describes information of an application. An MH-application descriptor may be included in an MH-AIT. 
     (45) MH-Transmission Protocol Descriptor 
     An MH-transmission protocol descriptor is used to specify a transmission protocol for broadcasting, communication, and the like, and to provide location information of an application depending on the transmission protocol. An MH-transmission protocol descriptor may be included in the MH-AIT. 
     (46) MH-Simplified Application Location Descriptor 
     An MH-simplified application location descriptor provides the detailed description of an acquisition destination of an application. An MH-simplified application location descriptor may be included in the MH-AIT. 
     (47) MH-Application Boundary Authority Setting Descriptor 
     An MH-application boundary authority setting descriptor provides a description for setting an application boundary and setting an authority for access to broadcasting resources for each region (URL). An MH-application boundary authority setting descriptor may be included in the MH-AIT. 
     (48) MH-Startup Priority Information Descriptor 
     An MH-startup priority information descriptor provides a description for specifying a startup priority of an application. An MH-startup priority information descriptor may be included in the MH-AIT. 
     (49) MH-Cache Information Descriptor 
     An MH-cache information descriptor provides a description used for cache control in a case where resources making up an application are saved in a cache when reuse of the application is assumed. An MH-cache information descriptor may be included in the MH-AIT. 
     (50) MH-Probability-Applied Delay Descriptor 
     An MH-probability-applied delay descriptor provides a description for delaying the time of execution of application control by a delay time set probabilistically, with the expectation that server access loads for acquiring the application are to be dispersed. An MH-probability-applied delay descriptor may be included in the MH-AIT. 
     (51) Link Destination PU Descriptor 
     A link destination PU descriptor describes another presentation unit (PU) to which a presentation unit may possibly make transition. A link destination PU descriptor may be included in a DCC table. 
     (52) Lock Cache Specifying Descriptor 
     A lock cache specifying descriptor describes a description for specifying a file to be cached and locked in a presentation unit. A lock cache specifying descriptor may be included in a DCC table. 
     (53) Unlock Cache Specifying Descriptor 
     An unlock cache specifying descriptor provides a description for specifying a file to be unlocked among locked files in a presentation unit. An unlock cache specifying descriptor may be included in a DCC table. 
     (54) Descriptor Set by Provider 
     Other descriptors set uniquely by the service provider and the like may be prepared. 
     &lt;Relation Between Data Transmission and Control Information in MMT Method&gt; 
     Here, the relation between data transmission and typical tables in the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment will be described with reference to  FIG.  6 E . 
     The broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment can perform data transmission through a plurality of routes such as TLV streams transmitted through the broadcast transmission path and IP data flows transmitted through the communication line. A TLV stream includes TLV-SI such as a TLV-NIT and an AMT and an IP data flow which is a data flow of IP packets. The IP data flow includes a video asset including a series of video MPUs and an audio asset including a series of audio MPUs. Similarly, the IP data flow may include a subtitle asset including a series of subtitle MPUs, a caption asset including a series of caption MPUs, and a data asset including a series of data MPUs. These various assets are associated in units of “package” by the MPT (MMT package table) which is stored in a PA message to be transmitted. Specifically, these assets are associated by describing a package ID (corresponding to “MMT_package_id_byte” parameter which will be shown later in  FIG.  17   ) and asset IDs (corresponding to “asset_id_byte” parameter which will be shown later in  FIG.  17   ) for respective assets included in the package, in the MPT. 
     The assets making up a package may be limited to assets in a TLV stream, but may include assets transmitted by an IP data flow through the communication line as shown in  FIG.  6 E . This is made possible by providing location information (corresponding to “MMT_general_location_info( )” which will be shown later in  FIG.  17   ) of the assets included in the package in the MPT so that the broadcast receiving apparatus  100  of the present embodiment can know the reference destination of each asset. Specifically, by changing the value of an “MMT_general_location_infonolocation_type” parameter which is included in the location information, the broadcast receiving apparatus  100  can refer to various pieces of data transmitted through various transmission routes including: 
     (1) data multiplexed in the same IP data flow as the MPT (location_type=0×00); 
     (2) data multiplexed in an IPv4 data flow (location_type=0×01); 
     (3) data multiplexed in an IPv6 data flow (location_type=0×02); 
     (4) data multiplexed in a broadcasting MPEG2-TS (location_type=0×03); 
     (5) data multiplexed in an MPEG2-TS format in an IP data flow (location_type=0×04); and 
     (6) data located by a specified URL (location_type=0×05). 
     Among the above reference destinations, (1) is, for example, an IP data flow that is received in the form of a digital broadcasting signal received by a tuner/demodulating unit  131  of the broadcast receiving apparatus  100  to be described later with reference to  FIG.  7 A . When the MPT is included also in an IP data flow on the side of a communication line and is transmitted, the reference destination of (1) may be changed to an IP data flow received by a LAN communication unit  121  to be described later through the communication line. Further, (2), (3), (5), and (6) described above are IP data flows received by the LAN communication unit  121  to be described later through the communication line. In addition, (4) described above can be used when to refer to the data multiplexed in MPEG2-TS received by the receiving function of receiving digital broadcasting signals transmitted by the MPEG2-TS method on the basis of location information (“MMT_general_location_info( )”) of the MPT included in a digital broadcasting signal transmitted by the MMT method, in the case of the broadcast receiving apparatus having both of a receiving function of receiving digital broadcasting signals transmitted by the MMT method and a receiving function of receiving digital broadcasting signals transmitted by the MPEG2-TS method, like a broadcast receiving apparatus  800  of a second embodiment to be descried later with reference to  FIG.  24   . 
     Note that the data making up the “package” is specified in the above-described manner, and a series of data grouped in a unit of “package” are treated as a “service” unit for digital broadcasting in the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. 
     Moreover, presentation time information of each MPU specified by the MPT (corresponding to “mpu_presentation_time” parameter to be shown later in  FIG.  13 B ) is described in the MPT, and a plurality of MPUs specified by the MPT can be presented (displayed or output) in conjunction with each other by using the presentation time information, with reference to a clock based on the NTP which is time information expressed by the UTC notation. Presentation control of various data using the clock based on the NTP will be described later. 
     The data transmission method of the present embodiment shown in  FIG.  6 E  further includes a concept of “event”. “Event” is a concept representing a so-called “program” handled by MH-EIT included in an M2 section message to be transmitted. Specifically, in the “package” indicated by an event package descriptor stored in the MH-EIT, a series of data included in a period between a start time (corresponding to a “start_time” parameter to be described later in  FIG.  21   ) stored in the MH-EIT and the end of a duration time (corresponding to a “duration” parameter to be described later in  FIG.  21   ) are data included in the concept of “event”. The MH-EIT can be used for various processes performed in units of “event” (e.g., process of creating a program guide, process of controlling timer recording and viewing reservation, process of protecting copy rights such as temporary data storage, etc.) in the broadcast receiving apparatus  100  of the present embodiment. 
     [Hardware Configuration of Broadcast Receiving Apparatus] 
       FIG.  7 A  is a block diagram showing an example of an internal configuration of the broadcast receiving apparatus  100 . The broadcast receiving apparatus  100  includes a main control unit  101 , a system bus  102 , a ROM  103 , a RAM  104 , a storage (accumulation) unit  110 , the LAN communication unit  121 , an extension interface unit  124 , a digital interface unit  125 , the tuner/demodulating unit  131 , a separating unit  132 , a video decoder  141 , a video color gamut conversion unit  142 , an audio decoder  143 , a caption decoder  144 , a subtitle decoder  145 , a subtitle synthesizing unit  146 , a subtitle color gamut conversion unit  147 , a data decoder  151 , a cache unit  152 , an application control unit  153 , a browser unit  154 , an application color gamut conversion unit  155 , a sound source unit  156 , a video synthesizing unit  161 , a monitor unit  162 , a video output unit  163 , an audio synthesizing unit  164 , a speaker unit  165 , an audio output unit  166 , and an operation input unit  170 . 
     The main control unit  101  is a microprocessor unit that controls the whole of the broadcast receiving apparatus  100  in accordance with a predetermined operating program. The system bus  102  is a data communication path through which data is exchanged between the main control unit  101  and each of operating blocks in the broadcast receiving apparatus  100 . 
     The ROM (Read Only Memory)  103  is a non-volatile memory storing a basic operating program such as operating system and other operating programs, and is provided as, for example, a rewritable ROM such as an EEPROM (Electrically Erasable Programmable ROM) and a flash ROM. The ROM  103  may store operation set values necessary for the operation of the broadcast receiving apparatus  100 . The RAM (Random Access Memory)  104  serves as a work area used when the basic operating program and other operating programs are executed. The ROM  103  and the RAM  104  may be integrated with the main control unit  101 . Further, a part of the memory region of the storage (accumulation) unit  110  may be used as the ROM  103  instead of providing the ROM  103  having the independent configuration shown in  FIG.  7 A . 
     The storage (accumulation) unit  110  stores the operating programs and operation set values of the broadcast receiving apparatus  100  and personal information of the user of the broadcast receiving apparatus  100 . In addition, the storage (accumulation) unit  110  can store an operating program downloaded through the Internet  200  and various data created by the operating program. Further, the storage (accumulation) unit  110  can store such contents as moving images, still images, and sounds that are acquired from broadcast waves or downloaded through the Internet  200 . A part of the memory region of the storage (accumulation) unit  110  may be used to substitute for a part or the whole of the function of the ROM  103 . Further, the storage (accumulation) unit  110  needs to retain the stored information even when power is not supplied to the broadcast receiving apparatus  100  from an external power source. Therefore, the storage (accumulation) unit  110  is provided as, for example, a non-volatile semiconductor element memory such as a flash ROM or an SSD (Solid State Driver) or a magnetic disk drive such as an HDD (Hard Disc Drive). 
     Note that the operating programs stored in the ROM  103  and the storage (accumulation) unit  110  can be added, updated and functionally extended by a downloading process from server devices on the Internet  200 . 
     The LAN (Local Area Network) communication unit  121  is connected to the Internet  200  via the router device  200   r , and transmits and receives data to and from server devices and other communication equipment on the Internet  200 . Further, the LAN communication unit  121  acquires an MMT data string (or part of it) of a program transmitted through the communication line. The LAN communication unit  121  may be connected to the router device  200   r  through wired communication or wireless communication such as Wi-Fi (registered trademark). The LAN communication unit  121  has a coding circuit, a decoding circuit, and the like. In addition, the broadcast receiving apparatus  100  may further include other communication units such as a BlueTooth (registered trademark) communication unit, an NFC communication unit, and an infrared communication unit. 
     The tuner/demodulating unit  131  receives broadcast waves transmitted from the radio tower  300   t  via the antenna  100   a , and tunes to (selects) a channel giving a service that the user wishes to have, under the control by the main control unit  101 . Further, the tuner/demodulating unit  131  demodulates a received broadcasting signal to acquire an MMT data string. Although the example of  FIG.  7 A  shows the configuration in which the broadcast receiving apparatus  100  has one tuner/demodulating unit, the broadcast receiving apparatus  100  may be configured to have a plurality of tuner/demodulating units for the purpose of simultaneously displaying a plurality of screens or recording a program on a different channel. 
     The separating unit  132  is an MMT decoder, and distributes a video data string, an audio data string, a caption data string, a subtitle data string, and the like which are real-time presentation elements to the video decoder  141 , the audio decoder  143 , the caption decoder  144 , the subtitle decoder  145 , and the like, respectively, based on a control signal included in an MMT data string inputted to the separating unit  132 . Data inputted to the separating unit  132  may be an MMT data string transmitted through the broadcast transmission path to the tuner/demodulating unit  131  and demodulated therein or an MMT data string transmitted through the communication line to the LAN communication unit  121 . Further, the separating unit  132  reproduces a multimedia application and filed data which is an element making up the multimedia application, and stores them temporarily in the cache unit  152 . In addition, the separating unit  132  extracts and outputs general-purpose data to the data decoder  151  in order to use it for the streaming of data used by a player that presents data other than video, audio, and subtitle or for the streaming of data for an application. Further, the separating unit  132  may perform control such as error correction, access restriction, and the like on the input MMT data string under the control by the main control unit  101 . 
     The video decoder  141  decodes a video data string input from the separating unit  132  and outputs video information. The video color gamut conversion unit  142  performs a color space conversion process on the video information decoded in the video decoder  141  when necessary, in preparation for a video synthesizing process in the video synthesizing unit  161 . The audio decoder  143  decodes an audio data string input from the separating unit  132  and outputs audio information. Further, for example, streaming data of an MPEG-DASH (MPEG-Dynamic Adaptive Streaming over HTTP) format or the like acquired from the Internet  200  through the LAN communication unit  121  may be inputted to the video decoder  141  and the audio decoder  143 . A plurality of video decoders  141 , video color gamut conversion units  142 , audio decoders  143 , and the like may be provided in order to simultaneously decode a plurality of kinds of video data strings and audio data strings. 
     The caption decoder  144  decodes a caption data string input from the separating unit  132  and outputs caption information. The subtitle decoder  145  decodes a subtitle data string input from the separating unit  132  and outputs subtitle information. The caption information output from the caption decoder  144  and the subtitle information output from the subtitle decoder  145  are subjected to a synthesizing process in the subtitle synthesizing unit  146  and then subjected to a color space conversion process in the subtitle color gamut conversion unit  147  when necessary, in preparation for the video synthesizing process in the video synthesizing unit  161 . In the present embodiment, among services presented simultaneously with the video of a broadcasting program and provided mainly as text information, a service related to the video contents is referred to as subtitle, while a service other than that is referred to as caption. When these services are not distinguished from each other, they are f referred to as subtitle. 
     The browser unit  154  presents a multimedia application file and filed data making up the multimedia application file, which are acquired from the cache unit  152  or a server device on the Internet  200  through the LAN communication unit  121 , in accordance with an instruction of the application control unit  153 , which interprets control information included in an MMT data string and control information acquired from a server device on the Internet  200  through the LAN communication unit  121 . Note that the multimedia application file may be, for example, an HTML (Hyper Text Markup Language) document or BML (Broadcast Markup Language) document. The application information output from the browser unit  154  is subjected to a color space conversion process in the application color gamut conversion unit  155  when necessary, in preparation for the video synthesizing process in the video synthesizing unit  161 . Further, the browser unit  154  causes the sound source unit  156  to reproduce application audio information. 
     The video synthesizing unit  161  receives video information output from the video color gamut conversion unit  142 , subtitle information output from the subtitle color gamut conversion unit  147 , application information output from the application color gamut conversion unit  155 , and the like, and performs a selection process and/or a superposition process as appropriate. The video synthesizing unit  161  has a video RAM (not shown), and the monitor unit  162  and the like are driven based on video information and the like inputted to the video RAM. Further, the video synthesizing unit  161  performs a scaling process and a superposing process of EPG (Electronic Program Guide) screen information created based on information such as MH-EIT included in MMT-SI when necessary under the control by the main control unit  101 . The monitor unit  162  is, for example, a display device such as liquid crystal panel, and offers the video information subjected to the selection process and/or superposition process in the video synthesizing unit  161 , to the user of the broadcast receiving apparatus  100 . The video output unit  163  is a video output interface that outputs the video information subjected to the selection process and/or superposition process in the video synthesizing unit  161 . 
     Note that the presentation function of the broadcast receiving apparatus  100  of the present embodiment has a logical plane structure for displaying a multimedia service in accordance with the intention of the service provider.  FIG.  7 B  shows an example of a configuration of the logical plane structure that the presentation function of the broadcast receiving apparatus  100  of the present embodiment has. In the logical plane structure, a caption plane that displays captions is located on the forefront layer, a subtitle plane that displays subtitles is located on the second layer, a multimedia plane that displays broadcast video, multimedia application or synthesized video thereof is located on the third layer, and a background plane is located on the rearmost layer. The subtitle synthesizing unit  146  and the video synthesizing unit  161  draw the caption information on the caption plane, the subtitle information on the subtitle plane, and the video information, application information, and the like on the multimedia plane. Further, background color is drawn on the background plane based on an LCT included in MMT-SI. Note that it is also possible to provide a plurality of multimedia planes on the third layer in accordance with the number of video decoders  141 . However, even when a plurality of multimedia planes is provided, application information and the like output from the application color gamut conversion unit  155  are displayed only on the multimedia plane located on the forefront layer. 
     The audio synthesizing unit  164  receives audio information output from the audio decoder  143  and application audio information reproduced in the sound source unit  156 , and performs a selection process and/or a mixing process as appropriate. The speaker unit  165  offers audio information subjected to the selection process and/or mixing process in the audio synthesizing unit  164  to the user of the broadcast receiving apparatus  100 . The audio output unit  166  is an audio output interface that outputs the audio information subjected to the selection process and/or mixing process in the audio synthesizing unit  164 . 
     The extension interface unit  124  is a group of interfaces for extending the function of the broadcast receiving apparatus  100 , and is configured of an analog video and audio interface, a USB (Universal Serial Bus) interface, a memory interface, and the like in the present embodiment. The analog video and audio interface receives analog video and audio signals from external video and audio output devices, and outputs analog video and audio signals to external video and audio input devices. The USB interface is connected to a PC and the like and transmits and receives data to and from the PC and the like. An HDD may be connected to the USB interface to record broadcasting programs and contents. A keyboard and other USB devices may also be connected to the USB interface. A memory card and other memory media are connected to the memory interface to transmit and receive data to and from them. 
     The digital interface unit  125  is an interface that outputs or receives coded digital video data and/or digital audio data. The digital interface unit  125  can output an MMT data string acquired by the demodulation in the tuner/demodulating unit  131 , an MMT data string acquired through the LAN communication unit  121 , or mixed data of the MMT data strings as it is. Further, the MMT data string input from the digital interface unit  125  may be controlled to be inputted to the separating unit  132 . It is also possible to output the digital contents stored in the storage (accumulation) unit  110  via the digital interface unit  125  or store the digital contents to the storage (accumulation) unit  110  via the digital interface unit  125 . 
     The digital interface unit  125  is provided as a DVI terminal, HDMI (registered trademark) terminal, or Displayer Port (registered trademark) terminal, and thus outputs and receives data in the format compliant with DVI specifications, HDMI specifications, or Displayer Port specifications. Alternatively, the digital interface unit  125  may output or receive data in a serial data format conforming to IEEE 1394 specifications and the like. Further, the digital interface unit  125  may be configured as an IP interface that performs the digital interface output via hardware such as Ethernet (registered trademark) and wireless LAN. In such a case, the digital interface unit  125  and the LAN communication unit  121  may share the hardware configuration. 
     The operation input unit  170  is an instruction input unit on which operation instructions to the broadcast receiving apparatus  100  are input. In the present embodiment, the operation input unit  170  is configured of a remote control receiving unit that receives commands transmitted from a remote controller and operation keys in which button switches are arranged (not shown), or may be configured of either the remote control receiving unit or the operation keys. Alternatively, the operation input unit  170  may be substituted by a touch panel overlaid on the monitor unit  162  or by a keyboard and others connected to the extension interface unit  124 . The remote controller (not shown) may be substituted by the portable information terminal  700  having a remote control command transmission function. 
     Note that, when the broadcast receiving apparatus  100  is a television receiver or the like as mentioned above, the video output unit  163  and the audio output unit  166  are not essential constituent elements of the present invention. Further, the broadcast receiving apparatus  100  is not limited to a television receiver, but may be an optical disc drive recorder such as DVD (Digital Versatile Disc) recorder, a magnetic disk drive recorder such as an HDD recorder, or an STB (Set Top Box). The broadcast receiving apparatus  100  may also be a PC (Personal Computer), a tablet terminal, a navigation device, a game machine, and the like having a digital broadcast receiving function and a broadcasting/communication cooperation function. When the broadcast receiving apparatus  100  is the DVD recorder, the HDD recorder, STB, or the like, the broadcast receiving apparatus  100  does not have to be provided with the monitor unit  162  and the speaker unit  165 . In such a case, the operation similar to that of the broadcast receiving apparatus  100  of the present embodiment is possible by connecting an external monitor and an external speaker to the video output unit  163 , the audio output unit  166 , or the digital interface unit  125 . 
     [System Configuration for Clock Synchronization/Presentation Synchronization in Broadcast Receiving Apparatus] 
       FIG.  7 C  shows an example of a system configuration for clock synchronization/presentation synchronization in the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. In the broadcasting system of the present embodiment, UTC expressed in a 64-bit-length NTP timestamp format is transmitted from the broadcast transmitting system to the receiver (broadcast receiving apparatus  100  of the present embodiment). In the NTP timestamp format, “second or more” of UTC is expressed by 32 bits, and “less than second” is also expressed by 32 bits. In practice, however, it is difficult to reproduce one second in 32-bit precision. For this reason, for example, a clock with a frequency of “24 th  power of 2” Hz (about 16.8 MHz) may be used as a system clock for video system synchronization and a system clock for operating a timepiece conforming to the NTP as shown in  FIG.  7 C . Considering the fact that the frequency of a system clock adopted in a conventional broadcasting system is 27 MHz and the hardware configuration of the receiver can be simplified, it is desirable that a clock whose frequency is exponentiation of 2 ranging from “24 th  power of 2” to “28 th  power of 2” is adopted as the system clock. 
     When the frequency of the system clock is set to exponentiation of 2 ranging from “24 th  power of 2” to “28 th  power of 2” in the broadcast transmitting system and the receiver as described above, 4 to 8 low-order bits in the NTP timestamp format transmitted from the broadcast transmitting system to the receiver, the low-order bits being not referred to by a PLL (Phase Locked Loop) system for reproducing the system clock or the timepiece conforming to the NTP, may be fixed to “0” or “1”. Namely, when the frequency of the system cock is “n th  power of 2” Hz (n=24 in  FIG.  7 C ), “32−n” low-order bits in the NTP timestamp format may be fixed to “0” or “1”. Alternatively, the receiver may perform the process without regard for the “32−n” low-order bits in the NTP timestamp format. 
     When receiving time information in the NTP format, the broadcast transmitting system builds the PLL system with a 32+n bit counter including VCO (Voltage Controlled Oscillator) with a frequency of “n th  power of 2” Hz, thereby providing a transmission system clock that synchronizes with the time information given from outside. Further, the broadcast transmitting system causes the overall signal processing units to operate in synchronization with the system clock of “n th  power of 2” Hz. In addition, the broadcast transmitting system periodically transmits the output of the transmission system clock as time information in the NTP-length format to the receiver through the broadcast transmission path. 
     The receiver receives the time information in the NTP-length format through the broadcast transmission path and reproduces a reception system clock by the PLL system including the VCO with the frequency of “n th  power of 2” Hz in the same manner as the broadcast transmitting system. As a result, the reception system clock works in synchronization with the transmission system clock of the broadcast transmitting system. Further, by operating the signal processing system of the receiver in synchronization with the system clock of “n th  power of 2” Hz, clock synchronization between the broadcast transmitting system and the receiver can be achieved, and thus the stable signal reproduction can be achieved. Further, decoding time and presentation time in units of presentation of video and audio signals are set based on the time information in the NTP format in the broadcast transmitting system. Here, an MPU timestamp descriptor to be described later with reference to  FIG.  13 B  is stored in the MPT which is stored in a PA message transmitted by a broadcasting signal. In the MPU timestamp descriptor shown in  FIG.  13 B , an “mpu_sequence_number (MPU sequence number)” parameter indicates a sequence number for an MPU that describes a timestamp, and an “mpu_presentation_time (MPU presentation time)” parameter indicates the presentation time of the MPU in the 64-bit NTP timestamp format. Thus, the receiver can control timing of presenting (displaying or outputting) video signals, audio signals, subtitles, captions, and the like for each of MPUs by referring to the MPU timestamp descriptor stored in the MPT. 
     In the case of paying attention to the above-described control of decoding timing and presentation timing of video and audio signals in units of presentation, synchronization of video and audio signals can be ensured by a clock with a frequency of about “16 th  power of 2” Hz (about 65.5 KHz). In this case, it is not necessary to refer to 16 low-order bits in an NTP timestamp format described in an MPU timestamp descriptor or the like. Namely, when a clock of “m th  power of 2” Hz, which is generated by dividing the frequency of system clock, is used for the control of decoding timing and presentation timing, it is not necessary to refer to “32−m” low-order bits in an NTP timestamp format described in an MPU timestamp descriptor or the like. Thus, the “32−m” low-order bits in the NTP timestamp format described in the MPU timestamp descriptor or the like may be fixed to “0” or “1”. 
     [Software Configuration of Broadcast Receiving Apparatus] 
       FIG.  7 D  is a software configuration diagram of the broadcast receiving apparatus  100  of the present embodiment, and shows respective software configurations of the ROM  103 , the RAM  104 , and the storage (accumulation) unit  110 . In the present embodiment, the ROM  103  stores a basic operating program  1001  and other operating programs, and the storage (accumulation) unit  110  stores a receiving function program  1002  and other operating programs. Further, the storage (accumulation) unit  110  includes a contents memory region  1200  storing such contents as moving images, still images, and sounds, an authentication information memory region  1300  storing authentication information and the like needed when access is made to an external portable terminal or server device, and a various information memory region storing other various types of information. 
     The basic operating program  1001  stored in the ROM  103  is loaded onto the RAM  104 , and the loaded basic operating program is executed by the main control unit  101  to configure a basic operation executing unit  1101 . Similarly, the receiving function program  1002  stored in the storage (accumulation) unit  110  is loaded onto the RAM  104 , and the loaded receiving function program is executed by the main control unit  101  to configure a receiving function executing unit  1102 . Further, the RAM  104  has a temporary memory region that temporarily saves data created at execution of each operating program when necessary. 
     In the following, for simpler description, a process in which the main control unit  101  loads the basic operating program  1001  from the ROM  103  onto the RAM  104  and executes the basic operating program  1001  to control each operating block is described simply as a process in which the basic operation executing unit  1101  performs control of each operating block. The same applies also to the description of other operating programs. 
     The receiving function executing unit  1102  controls each operating block of the broadcast receiving apparatus  100  to reproduce video and audio components transmitted by the broadcasting system of the present embodiment. In particular, a transport processing unit  1102   a  mainly controls the MMT decoder function of the separating unit  132 , and distributes a video data string, audio data string, and the like separated from an MMT data string to corresponding decode processing units, respectively. An AV decode processing unit  1102   b  mainly controls the video decoder  141 , the audio decoder  143 , and the like. An application processing unit  1102   c  mainly controls the cache unit  152 , the application control unit  153 , the browser unit  154 , and the sound source unit  156 . A caption processing unit  1102   d  mainly controls the caption decoder  144 . A subtitle processing unit  1102   e  mainly controls the subtitle decoder  145 . A general-purpose data processing unit  1102   f  mainly controls the data decoder  151 . An EPG generating unit  1102   g  interprets the descriptive contents of an MH-EIT and others included in MMT-SI to generate an EPG screen. A presentation processing unit  1102   h  mainly controls the video color gamut conversion unit  142 , the subtitle synthesizing unit  146 , the subtitle color gamut conversion unit  147 , the application color gamut conversion unit  155 , the video synthesizing unit  161 , and the audio synthesizing unit  164  based on the logical plane structure. 
     The above-described operating programs may be stored in advance in the ROM  103  and/or the storage (accumulation) unit  110  at the time of product shipment, or may be acquired from the other application server  500  and others on the Internet  200  through the LAN communication unit  121  after the product shipment. Alternatively, the operating programs stored in a memory card, optical disc, and the like may be acquired through the extension interface unit  124  and others. 
     [Configuration of Broadcast Station Server] 
       FIG.  8    is a block diagram showing an example of an internal configuration of the broadcast station server  300 . The broadcast station server  300  includes a main control unit  301 , a system bus  302 , a RAM  304 , a storage unit  310 , a LAN communication unit  321 , and a digital broadcasting signal transmission unit  360 . 
     The main control unit  301  is a microprocessor unit that controls the whole of the broadcast station server  300  in accordance with a predetermined operating program. The system bus  302  is a data communication path through which data is exchanged between the main control unit  301  and each of operating blocks in the broadcast station server  300 . The ROM  304  serves as a work area used when each operating program is executed. 
     The storage unit  310  stores a basic operating program  3001 , a broadcasting contents management/distribution program  3002 , and a broadcasting contents transmission program  3003 , and includes a broadcasting contents memory region  3200  and a metadata memory region  3300 . The broadcasting contents memory region  3200  stores the contents of broadcasting programs and others broadcasted by the broadcast station. The metadata memory region  3300  stores metadata such as the titles, IDs, summaries, casts, and broadcasting dates of the broadcasting programs and copy control information related to program contents. 
     Further, the basic operating program  3001 , the broadcasting contents management/distribution program  3002 , and the broadcasting contents transmission program  3003  stored in the storage unit  310  are loaded onto the RAM  304 , and the respective loaded programs are executed by the main control unit  301  to configure a basic operation executing unit  3101 , a broadcasting contents management/distribution executing unit  3102 , and a broadcasting contents transmission executing unit  3103 . 
     In the following, for simpler description, a process in which the main control unit  301  loads the basic operating program  3001  from the storage unit  310  onto the RAM  304  and executes the basic operating program  3001  to control each operating block is described simply as a process in which the basic operation executing unit  3101  performs control of each operating block. The same applies also to the description of other operating programs. 
     The broadcasting contents management/distribution executing unit  3102  performs management of the contents of broadcasting programs stored in the broadcasting contents memory region  3200  and the metadata stored in the metadata memory region  3300 , and performs control when the contents of broadcasting programs and metadata are delivered to a service provider based on a contract. Further, when delivering the contents of broadcasting programs and metadata to the service provider, the broadcasting contents management/distribution executing unit  3102  may perform a process of authenticating the service provider server  400  based on the contract when necessary. 
     The broadcasting contents transmission executing unit  3103  manages a time schedule and others when transmitting an MMT data string, which includes the contents of broadcasting programs accumulated in the broadcasting contents memory region  3200 , and the titles and IDs of broadcasting programs and copy control information of program contents accumulated in the metadata memory region  3300 , from the radio tower  300   t  via the digital broadcasting signal transmission unit  360 . 
     The LAN communication unit  321  is connected to the Internet  200 , and communicates with the service provider server  400  and others on the Internet  200 . The LAN communication unit  321  has a coding circuit, a decoding circuit, and the like. The digital broadcasting signal transmission unit  360  modulates an MMT data string composed of a video data string, audio data string, program data string, and the like of the contents of broadcasting programs accumulated in the broadcasting contents memory region  3200 , and transmits the modulated data string as the digital broadcast waves through the radio tower  300   t.    
     [Configuration of Service Provider Server] 
       FIG.  9    is a block diagram showing an example of an internal configuration of the service provider server  400 . The service provider server  400  includes a main control unit  401 , a system bus  402 , a RAM  404 , a storage unit  410 , and a LAN communication unit  421 . 
     The main control unit  401  is a microprocessor unit that controls the whole of the service provider server  400  in accordance with a predetermined operating program. The system bus  402  is a data communication path through which data is exchanged between the main control unit  401  and each of operating blocks in the service provider server  400 . The ROM  404  serves as a work area that is used when each operating program is executed. 
     The storage unit  410  stores a basic operating program  4001 , a video contents management/distribution program  4002 , and an application management/distribution program  4004 , and includes a video contents memory region  4200 , a metadata memory region  4300 , an application memory region  4400 , and a user information memory region  4500 . The video contents memory region  4200  stores the contents of broadcasting programs provided from the broadcast station server  300  as video contents, and stores video contents and the like created by the service provider. The metadata memory region  4300  stores metadata provided from the broadcast station server  300  and metadata related to video contents created by the service provider. The application memory region  4400  stores various applications and others for distributing the services cooperated with broadcasting programs in response to demands from television receivers. The user information memory region  4500  stores information (personal information, authentication information, etc.) related to a user who is permitted to access the service provider server  400 . 
     Further, the basic operating program  4001 , the video contents management/distribution program  4002 , and the application management/distribution program  4004  stored in the storage unit  410  are loaded onto the RAM  404 , and the respective loaded basic operating program, video contents management/distribution program, and application management/distribution program are executed by the main control unit  401  to configure a basic operation executing unit  4101 , a video contents management/distribution executing unit  4102 , and an application management/distribution executing unit  4104 . 
     In the following, for simpler description, a process in which the main control unit  401  loads the basic operating program  4001  stored in the storage unit  410  onto the RAM  404  and executes the basic operating program  4001  to control each operating block is described simply as a process in which the basic operation executing unit  4101  performs control of each operating block. The same applies also to description of other operating programs. 
     The video contents management/distribution executing unit  4102  acquires the contents and others of broadcasting programs and metadata from the broadcast station server  300 , manages video contents and others and metadata stored in the video contents memory region  4200  and the metadata memory region  4300 , and controls distribution of the video contents and others and metadata to television receivers. Further, when distributing the video contents and others and metadata to the television receivers, the video contents management/distribution executing unit  4102  may perform a process of authenticating the television receivers when necessary. Further, the application management/distribution executing unit  4104  manages applications stored in the application memory region  4400  and controls distribution of the applications in response to demands from the television receivers. Further, when distributing the applications to the television receivers, the application management/distribution executing unit  4104  may perform a process of authenticating the television receivers when necessary. 
     The LAN communication unit  421  is connected to the Internet  200 , and communicates with the broadcast station server  300  on the Internet  200  and the broadcast receiving apparatus  100  via the router device  200   r . The LAN communication unit  421  includes a coding circuit, a decoding circuit, and the like. 
     [Hardware Configuration of Portable Information Terminal] 
       FIG.  10 A  is a block diagram showing an example of an internal configuration of the portable information terminal  700 . The portable information terminal  700  includes a main control unit  701 , a system bus  702 , a ROM  703 , a RAM  704 , a storage unit  710 , a communication processing unit  720 , an extension interface unit  724 , an operation unit  730 , an image processing unit  740 , an audio processing unit  750 , and a sensor unit  760 . 
     The main control unit  701  is a microprocessor unit that controls the whole of the portable information terminal  700  in accordance with a predetermined operating program. The system bus  702  is a data communication path through which data is exchanged between the main control unit  701  and each of operating blocks in the portable information terminal  700 . 
     The ROM  703  is a memory storing a basic operating program such as operating system and other operating programs, and is provided as, for example, a rewritable ROM such as EEPROM and flash ROM. The RAM  704  serves as a work area used when the basic operating program and other operating programs are executed. The ROM  703  and the RAM  704  may be integrated with the main control unit  701 . Further, a part of the memory region of the storage unit  710  may be used as the ROM  703  instead of providing the ROM  703  having the independent configuration shown in  FIG.  10 A . 
     The storage unit  710  stores the operating programs and operation set values of the portable information terminal  700  and personal information of the user of the portable information terminal  700 . In addition, the storage unit  710  can store an operating program downloaded through the Internet  200  and various data created by the operating program. Further, the storage unit  710  can store such contents as moving images, still images, and sounds that are downloaded through the Internet  200 . A part of the memory region of the storage unit  710  may be used to substitute for a part or the whole of the function of the ROM  703 . Further, the storage unit  710  needs to retain the stored information even when power is not supplied to portable information terminal  700  from an external power source. Therefore, the storage unit  710  is provided as, for example, a non-volatile semiconductor element memory such as flash ROM or SSD or a magnetic disk drive such as an HDD. 
     Note that the operating programs stored in the ROM  703  and the storage unit  710  can be added, updated and functionally extended by the downloading process from server devices on the Internet  200 . 
     The communication processing unit  720  includes a LAN communication unit  721 , a mobile phone network communication unit  722 , and an NFC communication unit  723 . The LAN communication unit  721  is connected to the Internet  200  via the router device  200   r  and the access point  200   a , and transmits and receives data to and from server devices and other communication equipment on the Internet  200 . The LAN communication unit  721  is connected to the router device  200   r  and the access point  200   a  through wireless communication such as Wi-Fi (registered trademark). The mobile phone network communication unit  722  performs telephone communication (telephone call) and data transmission and reception through wireless communication with the base station  600   b  on the mobile phone communication network. The NFC communication unit  723  communicates wirelessly with the corresponding reader/writer when located in proximity to the reader/writer. The LAN communication unit  721 , the mobile phone network communication unit  722 , and the NFC communication unit  723  each have a coding circuit, a decoding circuit, an antenna, and the like. The communication processing unit  720  may further includes other communication units such as a BlueTooth (registered trademark) communication unit and an infrared communication unit. 
     The extension interface unit  724  is a group of interfaces for extending the function of the portable information terminal  700 , and is configured of a video and audio interface, a USB interface, a memory interface, and the like in the present embodiment. The video and audio interface receives video and audio signals from external video and audio output devices, and outputs video and audio signals to external video and audio input devices. The USB interface is connected to a PC and others and transmits and receives data to and from the PC and others. A keyboard and other USB devices may also be connected to the USB interface. A memory card and other memory media are connected to the memory interface to transmit and receive data to and from them. 
     The operation unit  730  is an instruction input unit that inputs operation instructions to the portable information terminal  700 . In the present embodiment, the operation unit  730  is composed of a touch panel  730   t  overlaid on a display unit  741  and operation keys  730   k  in which button switches are arranged. The operation unit  730  may be composed of either the touch panel  730   t  or the operation keys  730   k . The portable information terminal  700  may be operated using a keyboard or the like connected to the extension interface unit  724 , or may be operated using a separate terminal device connected through wired communication or wireless communication. Namely, the portable information terminal  700  may be operated through instructions from the broadcast receiving apparatus  100 . Further, the display unit  741  may be provided with the above-described touch panel function. 
     The image processing unit  740  includes the display unit  741 , an image signal processing unit  742 , a first image input unit  743 , and a second image input unit  744 . The display unit  741  is, for example, a display device such as liquid crystal panel, and offers image data processed in the image signal processing unit  742  to the user of the portable information terminal  700 . The image signal processing unit  742  has a video RAM (not shown), and the display unit  741  is driven based on image data inputted to the video RAM. Further, the image signal processing unit  742  has a function of performing processes of converting formats, superposing a menu and other OSD (On Screen Display) signals, and others when necessary. Each of the first image input unit  743  and the second image input unit  744  is a camera unit that inputs image data of surroundings or a target object by converting light input through a lens into electrical signals by using an electronic device such as a CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) sensor. 
     The audio processing unit  750  includes an audio output unit  751 , an audio signal processing unit  752 , and an audio input unit  753 . The audio output unit  751  is a speaker, and offers an audio signal processed in the audio signal processing unit  752  to the user of the portable information terminal  700 . The audio input unit  753  is a microphone, and converts the voice of the user and others into audio data to input it to the portable information terminal  700 . 
     The sensor unit  760  is a group of sensors that detect the state of the portable information terminal  700 , and includes a GPS receiving unit  761 , a gyro sensor  762 , a geomagnetic sensor  763 , an acceleration sensor  764 , an illuminance sensor  765 , and a proximity sensor  766  in the present embodiment. These sensors make it possible to detect the location, tilt, angle, and motion of the portable information terminal  700 , and the brightness and the proximity of an object around the portable information terminal  700 . The portable information terminal  700  may further include other sensors such as a pressure sensor in addition to these sensors. 
     The portable information terminal  700  may be provided as a cellular phone, a smartphone, or a tablet terminal, or may be provided as a PDA (Personal Digital Assistants), a notebook PC, or the like. Alternatively, the portable information terminal  700  may be provided as a digital still camera, a video camera capable of taking moving pictures, a portable game machine, a navigation device, or other portable digital devices. 
     The configuration example of the portable information terminal  700  shown in  FIG.  10 A  includes a number of constituent elements that are not essential to the present embodiment such as the sensor unit  760 , but even the configuration that does not include such constituent elements does not impair the effect of the present embodiment. The portable information terminal  700  may further include additional constituent elements (not shown) such as a digital broadcast receiving function and an electronic money settlement function. 
     [Software Configuration of Portable Information Terminal] 
       FIG.  10 B  is a software configuration diagram of the portable information terminal  700  of the present embodiment, and shows respective software configurations of the ROM  703 , the RAM  704 , and the storage unit  710 . In the present embodiment, the ROM  703  stores a basic operating program  7001  and other operating programs, and the storage unit  710  stores a cooperation control program  7002  and other operating programs. Further, the storage unit  710  includes a contents memory region  7200  storing such contents as moving images, still images, and sounds, an authentication information memory region  7300  storing authentication information and others needed when access is made to the television receiver or each server device, and a various information memory region storing other various types of information. 
     The basic operating program  7001  stored in the ROM  703  is loaded onto the RAM  704 , and the loaded basic operating program is executed by the main control unit  701  to configure a basic operation executing unit  7101 . Similarly, the cooperation control program  7002  stored in the storage unit  710  is loaded onto the RAM  704 , and the loaded cooperation control program  7002  is executed by the main control unit  701  to configure a cooperation control executing unit  7102 . Further, the RAM  704  has a temporary memory region that temporarily saves data created at execution of each operating program when necessary. 
     In the following, for simpler description, a process in which the main control unit  701  loads the basic operating program  7001  from the ROM  703  onto the RAM  704  and executes the basic operating program  7001  to control each operating block is described simply as a process in which the basic operation executing unit  7101  performs control of each operating block. The same applies also to the description of other operating programs. 
     The cooperation control executing unit  7102  manages device authentication, connection, data transmission and reception, and the like when the portable information terminal  700  performs operations cooperated with the television receiver. Further, the cooperation control executing unit  7102  has a browser engine function for executing an application cooperated with the television receiver. 
     The above-described operating programs may be stored in advance in the ROM  703  and/or the storage unit  710  at the time of product shipment, or may be acquired from the other application server  500  and others on the Internet  200  through the LAN communication unit  721  or the mobile phone network communication unit  722  after the product shipment. Alternatively, the operating programs stored in a memory card, optical disc, and the like may be acquired through the extension interface unit  724  and others. 
     [Time Management of Broadcast Receiving Apparatus] 
     The broadcast receiving apparatus of the present embodiment has two types of time management functions. The first time management function is the time management function based on the NTP, which has been already described above with reference to  FIG.  7 C . The second time management function is a time management function based on an MH-TOT, and is the time managed based on time information transmitted by the MH-TOT described in  FIG.  6 B . 
       FIG.  13 A  shows an example of a configuration of time information transmitted in the NTP format.  FIG.  13 B  shows an example of the data structure of the above-described MPU timestamp descriptor. A “reference_timestamp” parameter, “transmit_timestamp” parameter, and the like in the NTP format represent time data in the NTP-length format with a 64-bit length, and an “mpu_presentation_time” parameter in the MPU timestamp descriptor also represents time data in the NTP timestamp format with a 64-bit length. In the time data in the NTP-length format and the time data in the NTP timestamp format, “second or more” of UTC is expressed by 32 bits, and “less than second” is also expressed by 32 bits. Namely, the time information in the NTP format can transmit the time information up to “less than second”. Further, since the time information in the NTP format is expressed by the UTC notation, it is compatible with NTP data included in a signal received through the communication line (e.g., signal received by the LAN communication unit  121  of  FIG.  7 A ) as shown in  FIG.  3 (B) , unlike the clock management in the conventional digital broadcasting. 
     In contrast, the information transmitted by the MH-TOT is as follows. The broadcast receiving apparatus  100  can acquire the current date and Japan Standard Time through the MH-TOT.  FIG.  11 A  shows an example of the data structure of the MH-TOT. The broadcast receiving apparatus  100  can acquire the current date and current time from a “JST_time” parameter included in the MH-TOT. As shown in  FIG.  11 B , the “JST_time” parameter includes the information of 16 lower-order bits of coded data of the current date based on the Modified Julian Date (MJD) and the information of 24 bits representing the Japan Standard Time (JST) with 6 blocks of 4-bit binary-coded decimal (BCD). The current date can be calculated by performing a given calculation on the  16 -bit coded data of the MJD. The 6 blocks of 4-bit binary-coded decimal are made up of 2 blocks of 4-bit binary-coded decimal that represent “hour” with a two-digit decimal number, next 2 blocks of 4-bit binary-coded decimal that represent “minute” with a two-digit decimal number, and last 2 blocks of 4-bit binary-coded decimal that represent “second” with a two-digit decimal number. 
     Thus, the difference between time information based on the NTP and time information based on the MH-TOT is that the NTP is the information expressed in the UTC notation that covers time units up to “less than second” as described above, while the information based on the MH-TOT is the information expressed in the JST notation that covers time units up to “second”. 
     In the broadcast receiving apparatus  100  of the present embodiment, the time management function based on the NTP that is the time information expressed in the UTC notation is used for the synchronization in decoding process and display process of broadcasting signal contents including video, audio, subtitles, and captions, and other presentation data, and thus it is possible to achieve a highly accurate synchronization process. Further, by referring to time information expressed in the UTC notation instead of time information based on clocks of the broadcast station, it is also possible to perform the synchronization in decoding process and display process between broadcasting signal contents received by broadcasting signals including video, audio, subtitles, captions, and other data and data received through the communication line including video, audio, subtitles, and captions, and other data. 
     In addition, in the broadcast receiving apparatus  100  of the present embodiment, the time management function based on the “JST_time” including the 24-bit information expressed by 6 blocks of 4-bit binary-coded decimal in the MH-TOT may be used for performing each of the process of presenting the current time to the user and the process handling the MH-event information table (MH-EIT) described in  FIG.  6 B . In general, in the process of presenting the current time to the user, the broadcast receiving apparatus is rarely required to have the accuracy to the extent of less than “second”. Each piece of time information in the MH-event information table (MH-EIT) is stored as 24-bit information composed of 6 blocks of 4-bit binary-coded decimal, expressing “hour”, “minute”, and “second” with two-digit decimal numbers, like the EIT for conventional digital broadcasting that is transmitted by the MPEG2-TS method. For this reason, the time management function based on the MH-TOT of the broadcast receiving apparatus  100  of the present embodiment easily matches with a process using the MH-EIT. The process using the MH-EIT includes, specifically, a process of creating a program guide (to be described later), a process of controlling timer recording and viewing reservation, a process of protecting copy rights such as temporary data storage, and the like. This is because each of these processes is rarely required to have the accuracy to the extent of less than “second”, and the accuracy covering up to time unit “second” is enough. 
     Further, the process of creating a program guide, the process of controlling timer recording and viewing reservation, and the process of protecting copy rights such as temporary data storage are functions incorporated even in a receiver of the conventional digital broadcasting system using the MPEG2-TS method. Accordingly, if the broadcasting system of the present embodiment is configured in such a way as to execute the time management process compatible with the time management function of the conventional digital broadcasting system using the MPEG2-TS method in performing the process of creating a program guide, the process of controlling timer recording and viewing reservation, the process of protecting copy rights such as temporary data storage, and others, it becomes unnecessary to separately design process algorithms for these processes (process of creating a program guide, process of controlling timer recording and viewing reservation, process of protecting copy rights such as temporary data storage, etc.) when the broadcast receiving apparatus having both of a receiving function of digital broadcasting by the conventional MPEG2-TS method and a receiving function of digital broadcasting by the MMT method is configured, and the cost is thus reduced. 
     Further, even in a receiver that does not have the receiving function of digital broadcasting by the conventional MPEG2-TS method but has only the receiving function of digital broadcasting by the MMT method, algorithms for the function incorporated in the receiver of digital broadcasting system using the conventional MPEG2-TS method can be applied without creating new algorithms for the processes of creating a program guide, controlling timer recording and viewing reservation, protecting copy rights such as temporary data storage, and the like, and thus the development with less cost is possible. 
     Consequently, with the configuration in which the time management function based on the “JST_time” parameter in the MH-TOT is used for performing these processes (process of creating a program guide, process of controlling timer recording and viewing reservation, process of protecting copy rights such as temporary data storage, etc.), even the broadcast receiving apparatus for the digital broadcasting by the MMT method is made highly compatible with the broadcasting system using the conventional broadcasting method, and therefore can be provided at low cost. 
     As describe above, the broadcast receiving apparatus  100  of the present embodiment has the time management function using two types of time information different in accuracy from each other. One time information is expressed in the notation consistent with the conventional digital broadcasting system, while the other time information has higher resolution power than the one time information. 
     Using the latter time information for the process of synchronizing contents data of broadcasting signals achieves the information presentation process more accurate than that in the conventional broadcasting system, and using the former time information for the processes of creating a program guide, controlling timer recording and viewing reservation, protecting copy rights such as temporary data storage, and others allows the broadcast receiving apparatus to be provided at low cost. 
     Therefore, the broadcast receiving apparatus  100  of the present embodiment has the two types of time management function described above, and it is thus possible to achieve both of the highly accurate information presentation and the cost reduction. 
     [First Modification Example of Time Management] 
     Next, a first modification example of the time management in the broadcasting system of the present embodiment will be described below. 
     In the configuration of the first modification example, in order to improve the accuracy of time management by the NTP-based time management function that has already been described with reference to  FIG.  7 C , information related to an estimated delay time in time information transmission from a time management server (not shown) or the broadcast station server  300  to the broadcast receiving apparatus  100  is included in a broadcasting signal to be transmitted, and the information related to the estimated delay time is used to correct a system clock for the NTP-based time management function in the broadcast receiving apparatus  100 . 
     At this time, the information related to the estimated delay time may be included in a TMCC (Transmission and Multiplexing Configuration Control) region outside the TLV multiplexing stream instead of the TLV multiplexing stream shown in  FIG.  3 (A) . By transmitting the information in the TMCC region, the information related to the estimated delay time can be extracted without performing a process of separating the TLV multiplexing stream (demultiplexing process) in the broadcast receiving apparatus  100 . Namely, the information acquisition that is less likely to be affected by the delay in the separating process in the broadcast receiving apparatus  100  is possible, and thus a highly accurate correcting process of the system clock can be performed. An example of the data structure of time information transmitted in the TMCC signal will be described with reference to  FIG.  13 C . For example, the time information is preferably stored in a TMCC extension information region to be transmitted. In the time information in the TMCC extension information region of  FIG.  13 C , a “delta” parameter expresses the estimated value of transmission delay from a time management server that distributes the UTC or a server device that generates a TMCC signal to a general broadcast receiving apparatus, in the form of a 32-bit signed fixed-point value. Note that the 16 high-order bits thereof represent an integer part and  16  low-order bits thereof represent a decimal fraction. A “transmit_timestamp” parameter is a transmission timestamp, and expresses a time at which the TMCC signal is transmitted from the server device, in the NTP timestamp-length format. The 32 high-order bits thereof represent an integer part, and the 32 low-order bits thereof represent a decimal fraction. 
     In the first modification example, the broadcast receiving apparatus  100  of the present embodiment can correct more accurately the system clock for the NTP-based time management function, which is used for the process of synchronizing contents data of broadcasting signals, by using the information related to the estimated delay time (e.g., the “delta” parameter and/or the “transmit_timestamp” parameter) described in the time information stored and transmitted in the TMCC extension information region. 
     [Second Modification Example of Time Management] 
     Next, a second modification example of the time management in the broadcasting system of the present embodiment will be described below. 
     As describe above, the broadcast receiving apparatus  100  of the present embodiment has the time management function of managing the time by acquiring the current date and the Japan Standard Time from the information transmitted in the MH-TOT. The current date and the Japan Standard Time acquired from the information transmitted in the MH-TOT are superposed on video information, application information, and others in the video synthesizing unit  161  of the broadcast receiving apparatus  100 , and are offered to the user by outputting them to the monitor unit  162  and video output unit  163 . As described above, the MH-TOT has the data structure shown in  FIG.  11 A , and the broadcast receiving apparatus  100  can acquire the current date and the current time from the “JST_time” parameter in the MH-TOT. 
     However, since the “JST_time” parameter uses only the 16 low-order bits of the MJD coded data, calculation for determining a date of “April 22, 2038” ends up in arithmetic overflow, and the above-described predetermined calculation cannot express the date following “April 23, 2038”. To deal with this problem, in the second modification example of the present embodiment, the calculation method is switched depending on whether the value of the MJD is equal to or larger than a given value or the value is smaller than the given value so that the date following “April 23, 2038” can be expressed. 
       FIG.  12    shows a first calculation method that is used when the value of the MJD is equal to or larger than the given value and a second calculation method that is used when the value of the MJD is smaller than the given value. For example, when the given value is set to “32768 (0×8000)”, the current date is calculated by using the first calculation method in the case where the value of the MJD is equal to or larger than “32768”, and is calculated by using the second calculation method in the case where the value of the MJD is smaller than “32768”. Note that the case in which the value of the MJD is smaller than “32768” is equivalent to the case in which the most significant bit of the 16-bit data of the MJD is “0”. In this manner, the broadcast receiving apparatus  100  of the present embodiment can express the date following “April 23, 2038”. However, the given value can be determined arbitrarily, and it may be set to, for example, “16384 (0×4000)” or “49152 (0×C000)”. The condition for switching the calculation method may be set to the case where the 2 high-order bits of the 16-bit data of the MJD are “00” or the case where the 2 high-order bits of the  16 -bit data of the MJD are not “11”. Note that, when the given value is set to “32768” and the above-described method is used, a date preceding “September 4, 1948” cannot be expressed, but it does not pose a specific problem regarding the practical use of the television receiver. 
     Alternatively, the first calculation method and the second calculation method may be switched depending on a flag that replaces a part or the whole of a “reserved” parameter in the data structure of the MH-TOT of  FIG.  11 A  or depending on a newly added flag, instead of switching the first calculation method and the second calculation method depending on the result of comparison between the MJD and the given value. For example, in the case where the most significant bit of the 16-bit coded data of the MJD is “0”, the flag is set to “1” when the MJD value represents the date following “April 23, 2038”, and the flag is set to “0” when the MJD value does not represent the date following “April 23, 2038”. Then, when the flag is “1”, the second calculation method shown in  FIG.  12    is used, while when the flag is “0”, the first calculation method is used. Alternatively, a descriptor having the same meaning as the above-mentioned flag may be newly prepared and added to the MH-TOT. 
     As described above, in the broadcasting system of the present embodiment, absolute time data in the NTP format is transmitted, and the broadcast receiving apparatus  100  of the present embodiment has the NTP-based time management function. In addition, the broadcast receiving apparatus  100  of the present embodiment controls the decoding timing and presentation timing of video and audio signals in units of presentation by referring to NTP timestamps and others described in MPU timestamp descriptors set in units of MPU. As described above, the time information in the NTP format has the configuration shown in  FIG.  13 A . Further, the MPU timestamp descriptor has the configuration shown in  FIG.  13 B . 
     Accordingly, the broadcast receiving apparatus  100  of the present embodiment may select either the first calculation method or the second calculation method in accordance with the value of time data and others obtained by referring to the “reference_tiemstamp” parameter, the “transmit_timestamp” parameter, or the “mpu_presentation_time” parameter. Specifically, for example, when the most significant bit of the 64-bit time data in the NTP-length format is “0”, the second calculation method is used, and when the most significant bit is not “0”, the first calculation method is used. 
     By any of the above methods, the broadcast receiving apparatus  100  of the present embodiment can express the date following “April 23, 2038”. 
     [Channel Selection Process (Initial Scan) in Broadcast Receiving Apparatus] 
     The AMT of the broadcasting system of the present embodiment provides a list of IP packet multicast groups that is used to receive IP packets transmitted by the TLV multiplexing method without distinguishing them from IP packets transmitted through the communication line as much as possible. A plurality of IP multicast groups can be listed for one service identification. In addition, in order to describe a series of IP addresses efficiently, an address mask can be used. 
     In the broadcast receiving apparatus  100  of the present embodiment, a list of services acquired from the TLV-NIT can be stored in a non-volatile memory such as the ROM  103  and the storage unit  110  at the time of channel scan in the initial setting or rescan for the setting change, and a list of IP multicast groups corresponding to the services can be associated with the services as IP-related information and stored in the non-volatile memory. The list of services and IP-related information are stored in the non-volatile memory to be referred to constantly, so that a need of acquiring the TLV-NIT or AMT at the time of channel switching and others is eliminated, and thus the broadcasting contents can be efficiently acquired. 
       FIG.  14    is a diagram showing an example of an operation sequence at the time of channel scan (rescan) in the broadcast receiving apparatus  100  of the present embodiment. 
     When the channel scan starts, the receiving function executing unit  1102  sets an initial frequency value for the tuner/demodulating unit  131  and instructs the tuner/demodulating unit  131  to tune to the frequency value (S 101 ). When the tuner/demodulating unit  131  succeeds in locking to the set frequency value (S 102 : Yes), the receiving function executing unit  1102  acquires the TLV-NIT from a received signal (S 103 ). 
     When the TLV-NIT acquired in the process of S 103  is valid data (S 104 : Yes), the receiving function executing unit  1102  acquires information of a TLV stream ID, an original network ID, and the like from the acquired TLV-NIT (S 105 ).  FIG.  15 A  shows an example of the data structure of the TLV-NIT. The information of the TLV stream ID and the information of the original network ID can be acquired from a “tlv_stream_id” parameter and an “original_network_id” parameter, respectively. Furthermore, delivery system information related to physical conditions for the broadcast transmission path corresponding to the TLV stream ID and the original network ID is acquired from a delivery system descriptor (S 106 ), and a service ID list is acquired from a service list descriptor (S 107 ).  FIG.  15 B  shows an example of the data structure of a satellite delivery system descriptor.  FIG.  15 C  shows an example of the data structure of a service list descriptor. Note that, when the TLV-NIT has a plurality of different pieces of data such as the TLV stream ID, the original network ID, the delivery system information, and the service ID list, the processes of S 105  to S 107  are repeated. Subsequently, the receiving function executing unit  1102  creates a service list based on data acquired in the processes of S 105  to S 107  such as the TLV stream ID, the original network ID, the delivery system information, and the service ID list, and stores the created service list in the ROM  103  or the storage unit  110  (updates the service list at the time of rescan) (S 108 ). 
     Next, the receiving function executing unit  1102  then acquires an AMT from the received signal (S 109 ), and further acquires a list of IP multicast groups related to each service ID stored in the service list (S 110 ).  FIG.  15 D  shows an example of the data structure of the AMT. Note that, when the AMT has lists of IP multicast groups related to a plurality of service IDs, the process of S 110  is repeated. When there is a plurality of AMTS having lists of IP multicast groups related to different service IDs, the processes of S 109  and S 110  are repeated. Next, the receiving function executing unit  1102  then associates the list of IP multicast groups acquired in the process of S 110  with the service ID as IP-related information, and stores the IP-related information in the ROM  103  or the storage unit  110  (updates the IP-related information at the time of rescan) (S 111 ). 
     When the tuner/demodulating unit  131  fails in locking to the set frequency value in the process of S 102  (S 102 : No) and when the TLV-NIT acquired in the process of S 103  is not valid data (S 104 : No), the processes of S 105  to S 111  are not performed. 
     After finishing the process of S 111 , when finding that the frequency value set for the tuner/demodulating unit  131  is a final frequency value in a channel scan range (S 112 : Yes), the receiving function executing unit  1102  ends the operation sequence. On the other hand, when finding that the set frequency value is not the final frequency value in the channel scan range (S 112 : No), the receiving function executing unit  1102  increases the frequency value set for the tuner/demodulating unit  131  (S 113 ) and repeats the processes of S 102  to S 111 . Note that, if the service IDs for all services making up the broadcasting network can be acquired from one TLV-NIT and an AMT having lists of IP multicast groups related to the service IDs can be acquired, the processes of S 112  and S 113  are unnecessary. 
     Through the series of processes described above, when performing the channel scan for initial setting or the rescan for setting change, the broadcast receiving apparatus  100  of the present embodiment can create/update a list of services making up the broadcasting network (service list), and at the same time, create/update a list of IP multicast groups corresponding to each service (IP-related information) and store the created service list and IP-related information in a non-volatile memory such as the ROM  103  and the storage unit  110 . 
     Note that the rescan for setting change may be automatically performed when a change in the information in the table is detected by referring to respective “version_number” parameters of the TLV-NIT and AMT. When a change in the “version number” parameter of either the TLV-NIT or AMT is detected, only the information related to the table in which the change in parameter is detected may be automatically updated. However, when the above-described automatic updating is performed, execution of the automatic rescan should preferably be reported to the user. Alternatively, the change in the information in the table may be reported to the user so that the user makes a decision on whether or not to perform the rescan. 
     [Channel Selection Process (Channel Switching) in Broadcast Receiving Apparatus] 
       FIG.  16    is a diagram showing an example of an operation sequence at the time of channel selection (channel switching) in the broadcast receiving apparatus  100  of the present embodiment. 
     When the user gives a command to switch a channel by operating a remote controller and others (not shown), the receiving function executing unit  1102  interprets the command transmitted from the remote controller and specifies a service ID of an intended service (S 201 ). Next, the receiving function executing unit  1102  then starts to acquire an AMT from the signal received from the tuner/demodulating unit  131 . When succeeding in acquiring the AMT within a given time (S 202 : Yes), the receiving function executing unit  1102  acquires information related to a list of IP multicast groups corresponding to the service ID, from the acquired AMT (S 204 ). When failing to acquire the AMT within the given time (S 202 : No), the receiving function executing unit  1102  refers to the IP-related information stored in the ROM  103  or the storage unit  110  (S 203 ), thereby acquiring information related to the list of IP multicast groups corresponding to the service ID (S 204 ). Note that the receiving function executing unit  1102  may always refer to the IP-related information stored in the ROM  103  or the storage unit  110  without performing the determination process of S 202 . 
     Subsequently, the receiving function executing unit  1102  starts to acquire the TLV-NIT from the signal received from the tuner/demodulating unit  131 . When succeeding in acquiring the TLV-NIT within a given time (S 205 : Yes), the receiving function executing unit  1102  acquires delivery system information for acquiring an IP data flow corresponding to the service ID, from the acquired TLV-NIT (S 207 ). When failing to acquire the TLV-NIT within the given time (S 205 : No), the receiving function executing unit  1102  refers to the service list stored in the ROM  103  or the storage unit  110  (S 206 ), thereby acquiring the delivery system information for acquiring the IP data flow corresponding to the service ID (S 207 ). Note that the receiving function executing unit  1102  may always refer to the service list stored in the ROM  103  or the storage unit  110  without performing the determination process of S 205 . When the delivery system information has been acquired in the process of S 207 , the receiving function executing unit  1102  then controls the tuner/demodulating unit  131  with the frequency value specified by the acquired delivery system information, receives the IP data flow corresponding to the service ID (S 208 ), extracts an MMT data string from the received IP data flow, and outputs the MMT data string to the separating unit  132 . 
     In the separating unit  132 , the transport processing unit  1102 a acquires an MMTP packet with a packet ID “0”, from the input MMT data string (S 209 ), and further acquires an MPT from the acquired MMTP packet (S 210 ). Next, the transport processing unit  1102   a  then refers to an “MMT_package_id_byte” parameter included in the acquired MPT, and checks whether the 16 low-order bits of the “MMT_package_id_byte” parameter have the same value as the service ID. When the  16  low-order bits of the “MMT_package_id_byte” parameter have the same value as the service ID in the example of the data structure of the MPT shown in  FIG.  17    (S 211 : Yes), it is determined that the MMTP packet with the packet ID “0” is an MMTP packet having the data of the program corresponding to the service ID, and acquisition of an MFU is executed based on information included in the acquired MPT (S 216 ). 
     On the other hand, when the  16  low-order bits of the “MMT_package_id_byte” parameter do not have the same value as the service ID (S 211 : No), it is determined that the MMTP packet with the packet ID “0” is not the MMTP packet having data of the program corresponding to the service ID. In this case, the transport processing unit  1102   a  newly acquires a PLT (S 212 ), and checks the acquired PLT to confirm a packet ID (x in this case) of an MMTP packet that transmits an MPT having the “MMT_package_id_byte” parameter corresponding to the service ID (S 213 ). Further, the transport processing unit  1102 a then acquires an MMTP packet with a packet ID “x” from the above-mentioned input MMT data string (S 214 ), and acquires an MPT from the acquired MMTP packet (S 215 ). Further, the transport processing unit  1102   a  then acquires an MFU based on information included in the acquired MPT (S 216 ). 
     Note that the transport processing unit  1102   a  may always perform the processes of S 212  to S 215  without performing the processes of S 209  to S 211 . In this case, the process time can be reduced when the data of the program corresponding to the service ID is stored in an MMTP packet other than the MMTP packet with the packet ID “0”. 
     After the MFU is acquired in the process of S 216 , the transport processing unit  1102   a  extracts coded video data, coded audio data, and the like from the acquired MFU, and outputs the coded video data, the coded audio data, and the like to the video decoder  141 , the audio decoder  143 , and the like. Thereafter, a video and audio decoding process under the control by the AV decode processing unit  1102   b  and a presentation process under the control by the presentation processing unit  1102   h  are performed, but these processes are known to the public and detailed descriptions thereof are omitted. 
     Through the series of processes described above, the broadcast receiving apparatus  100  of the present embodiment can execute a channel selection (channel switching) operation. In particular, as described above with reference to  FIGS.  14  and  16   , a service list and IP-related information are created and are stored in a non-volatile memory such as the ROM  103  and the storage unit  110  so as to be referred to constantly at the time of channel scan for initial setting or rescan for setting change, and the service list and IP-related information stored in a non-volatile memory such as the ROM  103  and the storage unit  110  are referred to at the time of channel selection (channel switching), so that the efficiency of the channel selection (channel switching) operation can be improved. Namely, the time taken from the start to end of the channel selection (channel switching) can be reduced, compared to a case where the AMT and TLV-NIT are acquired again at the time of channel selection (channel switching). 
     [Screen Layout Control of Broadcast Receiving Apparatus] 
     The broadcast receiving apparatus  100  of the present embodiment can control the screen layout based on the description of an LCT.  FIG.  18    shows an example of the data structure of the LCT. 
     In  FIG.  18   , a “left_top_pos_x” parameter and a “right_down_pos_x” parameter indicate a horizontal position on the top left of a region and a horizontal position on the bottom right of the region in terms of the ratio of the number of pixels to the total number of pixels arranged in the horizontal direction, respectively, when the left side of the full-screen display is defined as “0” and the right side of the same is defined as “100”. A “left_top_pos_y” parameter and a “right_down_pos_y” parameter indicate a vertical position on the top left of the region and a vertical position on the bottom right of the region in terms of the ratio of the number of pixels to the total number of pixels arranged in the vertical direction, respectively, when the top side of the full-screen display is defined as “0” and the bottom side of the same is defined as “100”. Further, a “layer_order” parameter indicates a relative position in the depth direction of the region. 
     Examples of layout assignment to layout numbers based on the parameter settings are shown in  FIGS.  19 A to  19 D  together with set values for the parameters. 
       FIG.  19 A  shows default layout setting of the broadcast receiving apparatus  100  of the present embodiment, and shows an example in which one region is set for the full-screen.  FIG.  19 B  shows an example in which the full-screen is divided into three regions, and the respective regions are defined as “region  0 ”, “region  1 ” and “region  2 ”. For example, when the full-screen is made up of 7680 horizontal pixels×4320 vertical pixels, the “region  0 ” is set within a range of (0, 0)-(6143, 3455) because the “left_top_pos_x” parameter is “0”, the “left_top_pos_y” parameter is “0”, the “right_down_pos_x” parameter is “80”, and the “right_down_pos_y” parameter is “80”. In the same manner, the “region  1 ” is set within a range of (6144, 0) to (7679, 4319) , and the “region  2 ” is set within a range of (0, 3456) to (6143, 4319). 
       FIG.  19 C  shows an example in which three regions are set like the example of  FIG.  19 B . In the example of  FIG.  19 C , however, the “region  0 ” is set within a range of (0, 0) to (7679, 4319), and the “region  1 ” and “region  2 ” are set within the same ranges of the “region  1 ” and “region  2 ” described above and are located in front of the “region  0 ” in accordance with the setting of the “layer_order” parameter.  FIG.  19 D  shows an example in which the “region  0 ” is set in a device  0  (default device: broadcast receiving apparatus  100  in the present embodiment) and the “region  1 ” is set in a device  1  (portable information terminal  700  in the present embodiment). 
     As described above, in the broadcasting system of the present embodiment, screen layout control for displaying multimedia services on the receiver in a manner intended by the service provider can be performed by using the LCT. 
     Note that decimal fractions that are generated when the screen is divided in accordance with the setting values of the “left_top_pos_x” parameter and others are rounded up or down, or rounded off (or in the case of binary numbers, “0” is rounded down while “1” is rounded up). For example, when the full-screen is made up of 7680 horizontal pixels×4320 vertical pixels and the “left_top_pos_x” parameter of the “region  0 ” is “0”, the “left_top_pos_y” parameter is “ 0 ”, the “right_down_pos_x” parameter is “51”, and the “right_down_pos_y” parameter is “51”, the “region  0 ” may be set within a range of (0, 0)-(3916, 2203) by rounding up decimal fractions or may be set within a range of (0, 0)-(3915, 2202) by rounding down decimal fractions. Alternatively, decimal fractions may be rounded up or down in units of 8-pixel blocks or 16-pixel blocks in consideration of macro-blocks at the time of an image compression process. Through the process described above, region setting based on the LCT and conversion of the resolution of multimedia contents in the above region can be performed efficiently. 
     [Exceptional Process of Screen Layout Control of Broadcast Receiving Apparatus] 
     Even when the control of the screen layout region is performed based on the LCT in the broadcast receiving apparatus  100  of the present embodiment, if the user gives an instruction to display an EPG screen, the broadcast receiving apparatus  100  of the present embodiment can perform the screen layout control in which the descriptive contents of the LCT is left out of account, as an exceptional process.  FIG.  20 A  shows an example of an operation of the exceptional process of the screen layout control based on the LCT. 
     When the screen layout control similar to that shown in  FIG.  19 B  is performed based on the descriptive contents of the LCT, a video of broadcasting program is displayed in the “region  0 ”, and broadcasting contents such as program-cooperation data cooperated with the broadcasting program are displayed in the “region  1 ” and the “region  2 ”, if the user gives an instruction to display an EPG screen with the remote controller (not shown), the broadcast receiving apparatus  100  of the present embodiment shifts the screen layout setting back to the default setting (i.e., a state in which the screen layout control similar to that shown in  FIG.  19 A  is performed) as shown in  FIG.  20 A (A) regardless of the descriptive contents of the LCT, and controls the screen layout to display the EPG screen on the entire screen. Further, when the user gives an instruction to end the display of the EPG screen, the broadcast receiving apparatus  100  executes again the screen layout control in accordance with the descriptive contents of the LCT. 
     By performing the control described above, the EPG screen can be displayed in a large size and easiness to see the EPG screen can be improved, compared to the case where the EPG screen is displayed while maintaining the control of screen layout region as shown in  FIG.  20 A (B). 
     Note that the exceptional process of the screen layout control is applied not only to the case of displaying the EPG screen but also to the case of displaying sub-screens of various setting screens (timer recording setting screen in the example of  FIG.  20 B (A)) or displaying dual screens in the broadcast receiving apparatus  100 , as shown in  FIG.  20 B . 
     In the case of the timer recording setting screen shown in (A) of  FIG.  20 B , a display area of broadcasting contents is shifted from the full-screen region to a sub-screen region on the right bottom corner of the screen. In the case of the dual screen display shown in (B) of  FIG.  20 B , the display area of broadcasting contents is shifted from the full-screen region to a divided screen region in the middle left side of the screen. In both cases, since the display area for displaying broadcasting contents is narrowed, compared to the case of using the entire screen, it is not preferable to maintain the control of screen layout region in the display area (that is, a plurality of broadcasting contents is kept displayed simultaneously in divided regions) from the viewpoint of offering fine visibility. For this reason, in the above-described situation, the broadcast receiving apparatus  100  of the present embodiment selects the broadcasting contents of the “region  0 ” and displays only the selected contents in the display area. Note that the broadcasting contents of the “region  1 ” or “region  2 ” may be selected and displayed depending on a region selection state right before the selection. 
     By performing the control described above, the easiness to see the broadcasting contents can be improved, compared to the case where various broadcasting contents are displayed while maintaining the control of screen layout region. The same applies also to the cases of displaying a sub-screen for a timer recording program list, displaying internet contents on a browser, and others. 
     [Display of EPG in Broadcast Receiving Apparatus] 
     In the broadcasting system of the present embodiment, time-series information related to events (so-called programs) included in services making up the broadcasting network is transmitted in the form of MH-EIT.  FIG.  21    shows an example of the data structure of the MH-EIT of the present embodiment. The MH-EIT is classified into two classes by a table ID (corresponding to a “table_id” parameter in  FIG.  21   ), and can provide information of the current and next events in its own TLV stream and schedule information of events in its own TLV stream. The broadcast receiving apparatus  100  of the present embodiment refers to the MH-EIT and others to identity a service with a service ID (corresponding to a “service_id” parameter in  FIG.  21   ), thereby acquiring information of the start time, broadcasting time, and the like of each event to create an EPG screen. Further, the broadcast receiving apparatus  100  can display the created EPG screen on the monitor unit  162  by superposing it on video information and others in the video synthesizing unit  161 . 
       FIG.  22 A  is a diagram showing an example of an EPG screen in the broadcast receiving apparatus  100  of the present embodiment. An EPG screen  162   a  has a matrix form with the vertical axis representing time and the horizontal axis representing service IDs (channels), and displays detailed information of broadcasting programs to be broadcasted in each channel in each time zone. Further, detailed information  162   a   1  of each broadcasting program is composed mainly of a title region  162   a   2  and a detail description region  162   a   3 . 
     In the title region  162   a   2 , symbols and others expressing the title and properties of the broadcasting program are displayed. The symbols and others expressing the properties of the broadcasting program are, for example, symbols/characters indicating that the broadcasting program is a new program or rerun program, or may be a mark or the like standing for “data” indicating that the program supports data broadcasting by a broadcasting service, or may be a mark  162   a   4  or the like standing for “NetWork” indicating that contents, applications, and others related to the broadcasting program can be acquired through the network. In addition, the symbols and others expressing the properties of the broadcasting program may be substituted by differentiating the background color of the detailed information  162   a   1  from others or enclosing the display region of the detailed information  162   a   1  with a thick line. 
     Note that, even when control information (messages, tables, descriptors, etc.) in the broadcasting system of the present embodiment indicates that contents, applications, and others related to the broadcasting program can be acquired through the network, if access to server devices on the network cannot be made for such a reason that a LAN cable is not connected to the LAN communication unit  121  of the broadcast receiving apparatus  100 , the screen may be controlled so as not to display the mark  162   a   4  or the like standing for “NetWork”. 
     In addition, when the broadcasting program is a network-distribution program distributed through the Internet  200  and therefore cannot be acquired from broadcast waves, and further the broadcast receiving apparatus  100  cannot access server devices on the network like in the case described above, the screen may be controlled so that a region of detailed information  162   b   1  displayed on an EPG screen  162   b  is grayed out as shown in  FIG.  22 B . Namely, the screen is controlled so as not to display detailed information of a network-distribution program that the user is not allowed to view. Alternatively, the gray-out process may be substituted by differentiating the background color of the detailed information  162 b 1  from others. It is also possible to notify the user that the broadcast receiving apparatus  100  is incapable of accessing server devices on the network or the user is not allowed to view a network-distribution program associated with the detailed information  162   b   1 , by a popup message or the like when the user operates the remote controller (not shown) to select the detailed information  162   b   1 . 
     Through the control described above, the broadcast receiving apparatus  100  can provide the user with information of broadcasting programs in a form that does not give any sense of discomfort to the user in accordance with the network connection state. 
       FIG.  22 C  is a diagram showing another example of the EPG screen in the broadcast receiving apparatus  100  of the present embodiment. In  FIG.  22 C , “M1 television”, “M2 broadcasting”, “M3 channel”, “M4 TV”, “Television M5”, and others are the names of broadcast stations of respective channels, and the “M2 broadcasting” station provides broadcasting programs distributed through broadcast waves as well as network-distribution programs (information  162   c   1  indicated in a column of “network broadcasting” in  FIG.  22 C ) distributed through the Internet  200  at the same time. 
     As shown in  FIG.  22 C , when a channel that provides only the network-distribution programs distributed through the Internet  200  is present, the screen is usually controlled to display the information of all the channels (including the information  162   c   1 ) as shown by an EPG screen  162   c  in  FIG.  22 C (A). Meanwhile, in the case where the broadcast receiving apparatus  100  cannot access server devices on the network or the like, the screen may be controlled so as not to display information of the channel of “M2 broadcasting (network broadcasting)” that provides only the network-distribution programs distributed through the Internet  200  (information  162   c   1  in  FIG.  22 C (A)) as shown by an EPG screen  162   d  in  FIG.  22 C (B). 
     Through the control described above, it becomes unnecessary for the user of the broadcast receiving apparatus  100  to check the information of a channel that provides programs that the user is not allowed to view. 
     [Display of Emergency Warning Broadcasting in Broadcast Receiving Apparatus] 
     The broadcast receiving apparatus  100  of the present embodiment can perform a process of receiving emergency warning broadcasting when an emergency warning broadcasting start control signal bit of a TMCC signal, which is included in transmission data including a TLV stream, changes from “0” to “1”. 
     The emergency warning broadcasting may be provided as an application that displays a warning message on the full-screen scale or may be provided as character information in the form of a caption message. It is preferable that the character information in the form of a caption message is displayed regardless of the condition of the broadcast receiving apparatus  100  just before reception of the emergency warning broadcasting in a case where the emergency warning broadcasting is provided as character information in the form of a caption message. Namely, as shown in  FIG.  23   , when the broadcast receiving apparatus  100  receives emergency warning broadcasting in a state where the user views a regular broadcasting program by watching a program screen  162   e  of the broadcasting program displayed on the monitor unit  162 , character information  162   e   1  by the emergency warning broadcasting is superposed and displayed on the program screen  162   e . In the same manner, when the broadcast receiving apparatus  100  receives emergency warning broadcasting in a state where an EPG screen  162 f is displayed on the monitor unit  162  in accordance with an instruction given by the user to display the EPG screen, character information  162   f   1  by the emergency warning broadcasting is superposed and displayed on the EPG screen  162   f.    
     Through the control described above, even when the user selects an EPG screen, a setting screen, a timer recording program list screen, or an internet browser screen and causes the broadcast receiving apparatus  100  to display such a screen, it is possible to avoid overlooking important character information based on the received emergency warning broadcasting. Note that this control may be performed for the character information of an ordinary caption other than the emergency warning broadcasting. 
     [Various Exceptional Processes] 
     When failing to acquire data of a transmission path other than a TLV stream in the same package, the broadcast receiving apparatus  100  of the present embodiment may perform, for example, the following exceptional processes. 
     As described above with reference to  FIG.  6 E , in the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment, data acquired from a TLV stream and data acquired from a transmission path other than the TLV stream can be included in the same package, based on location information (corresponding to the “MMT_general_location_info( )” in  FIG.  17   ) stored in the MPT. However, the data transmission path other than the TLV stream that is indicated by the location information (e.g., IPv4 data flow, IPv6 data flow, MPEG2-TS of broadcasting, etc.) is a receiving function different from a receiving function of TLV/MMT streams. For this reason, even when the broadcast receiving apparatus  100  is in operation, the data may not be acquired from such a data transmission path in a situation where the receiving function of the data transmission path is not working, a situation where the receiving function is working but a relay device and others are not operating, a situation where a wired or wireless connection of the transmission path is not established, and a situation where the broadcast receiving apparatus  100  is placed in an environment in which the data transmission path cannot be connected. 
     In such situations, when the broadcast receiving apparatus  100  of the present embodiment receives an event in which the location information stored in the MPT indicates that the data acquired from the TLV stream and the data acquired from the transmission path other than the TLV stream are correlated to be included in the same package, the broadcast receiving apparatus  100  may perform the following operations. 
     For example, when an LCT specifies a plurality of regions on the screen as shown in  FIGS.  19 B and  19 C , and video included in the TLV stream and data acquired from a transmission path other than the 
     TLV stream are correlated so that the video is displayed in the “region  0 ” and the data is displayed in the “region  1 ” and “region  2 ”, but the data from the transmission path other than the TLV stream to be displayed in the “region  1 ” and “region  2 ” cannot be acquired, the layout display of a plurality of regions specified by the LCT may be forbidden. Specifically, even when the LCT is received, the video contents received from the TLV stream is kept displayed in the “region  0 ” in the default layout display shown in  FIG.  19 A , and this layout is prevented from shifting to the layout display of a plurality of regions shown in  FIGS.  19 B and  19 C . Further, even if an instruction to make a layout change from the default layout to the layout specified by the LCT is inputted to the operation input unit  170  of  FIG.  7 A  in this state, a shift to the layout display of a plurality of regions of  FIGS.  19 B and  19 C  may be prevented by maintaining the default layout of  FIG.  19 A  or shifting the screen to a different data broadcasting screen. 
     As another operation example when an LCT specifies a plurality of regions on the screen as shown in  FIGS.  19 B and  19 C , and video included in the TLV stream and data acquired from a transmission path other than the TLV stream are correlated so that the video is displayed in the “region  0 ” and the data is displayed in the “region  1 ” and “region  2 ”, but the data from the transmission path other than the TLV stream to be displayed in the “region  1 ” and “region  2 ” cannot be acquired, a display frame for the plurality of regions of 
       FIGS.  19 B and  19 C  specified by the LCT is displayed temporarily to display a background color or a given still image in the “region  1 ” and “region  2 ”, and if the data from the transmission path other than the TLV stream indicated by the location information of the MPT cannot be acquired after an elapse of a given time, the display layout is shifted back to the default layout display shown in  FIG.  19 A . In this case, it is preferable that the screen is controlled so that the program video included in the TLV stream is kept displayed in the “region  0 ” even in the layout change shown in  FIGS.  19 A,  19 B , and  19 C because the program video itself for the user continues. 
     Further, even in a state where the video contents received in the TLV stream are displayed in the “region  0 ” in the default layout display of  FIG.  19 A  because the data from the transmission path other than the TLV stream to be displayed in the “region  1 ” and “region  2 ” cannot be acquired, operations of various communication functions and receiving functions of the broadcast receiving apparatus  100  of the present embodiment are started or communication environment and communication state of the various communication functions and reception environment and reception state of the various receiving functions are changed in some cases, with the result that it becomes possible to acquire the data from the transmission path other than the TLV stream to be displayed in the “region  1 ” and “region  2 ”. In such a case, the broadcast receiving apparatus  100  of the present embodiment may immediately shift the display layout from the default layout display of  FIG.  19 A  to the layout of a plurality of regions of  FIGS.  19 B and  19 C  specified by the LCT so that the video contents received from the TLV stream are displayed in the “region  0 ” and the data acquired from the transmission path other than the TLV stream is displayed in the “region  1 ” and “region  2 ”. Alternatively, the layout change may be performed after an instruction to make a layout change from the default layout to the layout specified by the LCT is inputted to the operation input unit  170 , instead of performing the layout change immediately. 
     [Copy Right Protection Function] 
     In the digital broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment, the copy control information may be included in the MPT so that the copy control information is transmitted to indicate copy control states of contents that the MPT refers to, and the copy control states includes “freely copiable” (which may be divided into two types such as “freely copiable and requiring encoding process upon storage and output” and “freely copiable and not requiring encoding process upon storage and output”), “copiable only for one generation”, “copiable given times” (e.g., a so-called “dubbing  10 ” if copiable nine times +allowing move once), and “copy prohibited”. In this case, the broadcast receiving apparatus  100  of the present embodiment may be configured to control the processes of storing the contents in the storage (accumulation) unit  110 , recoding the contents on a removable recording medium, outputting the contents to external equipment, copying the contents to external equipment, and moving the contents to external equipment in accordance with the copy control information. Note that data to be subjected to the storage process may include not only the data stored in the storage (accumulation) unit  110  in the broadcast receiving apparatus  100  but also a record that is protected by an encoding process or the like so as to be reproduced only by the broadcast receiving apparatus  100 . Specifically, data to be subjected to the storage process includes the data recorded in an external recording device in the state of being reproduced only by the broadcast receiving apparatus  100 . 
     Specific examples of processes based on the copy control information will be described below. 
     First, when the copy control information included in the MPT indicates “freely copiable”, the broadcast receiving apparatus  100  of the present embodiment is allowed to perform the processes of storage to the storage (accumulation) unit  110 , recoding on the removable recording medium, output to external equipment, copy to external equipment, and move to external equipment, without limitations. However, in the case where “freely copiable” is divided into “freely copiable and requiring encoding process upon storage and output” and “freely copiable and not requiring encoding process upon storage and output” and when the copy control information indicates “freely copiable and requiring encoding process upon storage and output”, the broadcast receiving apparatus  100  is allowed to perform the processes of storage to the storage (accumulation) unit  110 , recoding on the removable recording medium, output to external equipment, copy to external equipment, and move to external equipment any number of times without any limitation, but has to apply the encoding process in any cases. 
     Further, when the copy control information included in the MPT indicates “copiable only for one generation”, the broadcast receiving apparatus  100  of the present embodiment is allowed to store encoded contents in the storage (accumulation) unit  110 , but when the stored contents are to be outputted to external equipment for viewing, the broadcast receiving apparatus  100  has to output the contents after encoding the contents together with the copy control information indicating “copy prohibited”. However, the broadcast receiving apparatus  100  is allowed to perform a so-called moving process to the external equipment (the process of copying the contents to the external equipment and disabling the reproduction of the contents in the storage (accumulation) unit  110  of the broadcast receiving apparatus  100  by, for example, deleting the contents). 
     Further, when the copy control information included in the MPT indicates “copiable given times”, the broadcast receiving apparatus  100  of the present embodiment is allowed to store encoded contents in the storage (accumulation) unit  110 , but when the stored contents are to be outputted to external equipment for viewing, the broadcast receiving apparatus  100  has to output the contents after encoding the contents together with the copy control information indicating “copy prohibited”. However, the broadcast receiving apparatus  100  is allowed to perform the copying and move process of contents to the external equipment predetermined times. In the case of the so-called “dubbing  10 ”, the broadcast receiving apparatus  100  is allowed to perform copying to the external equipment nine times and the moving process to the external equipment once. 
     Further, when the copy control information included in the MPT indicates “copy prohibited”, the broadcast receiving apparatus  100  of the present embodiment is prohibited from copying to the storage (accumulation) unit  110 . However, when the broadcast receiving apparatus  100  is configured to have a “temporary storage” mode in which storage to the storage (accumulation) unit  110  is allowed only for a predetermined given time or a given time specified by control information (e.g., the MH-Expire descriptor or the like shown in  FIG.  6 D ) included in a broadcasting signal, the broadcast receiving apparatus  100  is allowed to store the contents temporarily in the storage (accumulation) unit  110  even when the copy control information included in the MPT indicates “copy prohibited”. When the contents for which the copy control information included in the MPT indicates “copy prohibited” are to be outputted to external equipment for viewing, the broadcast receiving apparatus  100  has to output the contents after encoding the contents together with the copy control information indicating “copy prohibited”. 
     Note that the output of the contents to the external equipment for viewing can be performed by the video output unit  163  and the audio output unit  166  or through the digital IF unit  125  and the LAN communication unit  121  of  FIG.  7 A . The copying or moving process to the external equipment can be performed through the digital IF unit  125  and the LAN communication unit  121  of  FIG.  7 A . 
     According to the processes described above, proper contents protection can be achieved in accordance with the copy control information correlated with contents. 
     Further, the copying process of the contents for which the copy control information indicates copy limitations such as “copiable only for one generation”, “copiable given times”, and “copy prohibited” to external equipment through the LAN communication unit  121  may be allowed only when the IP address of the external equipment which is the destination of a transmission packet sent from the broadcast receiving apparatus  100  is present in the same subnet as the IP address of the broadcast receiving apparatus  100 , and may be prohibited when the IP address of the external equipment is outside the subnet in which the IP address of the broadcast receiving apparatus  100  is present. The same applies also to the case of the contents for which the copy control information indicates “freely copiable and requiring encoding process upon storage and output”. 
     Similarly, the process of storing the contents for which the copy control information indicates copy limitations such as “copiable only for one generation”, “copiable given times”, and “freely copiable and requiring encoding process upon storage and output” temporarily in the storage (accumulation) unit  110  and then moving the contents to external equipment through the LAN communication unit  121  may be allowed only when the IP address of the external equipment which is the destination of a transmission packet sent from the broadcast receiving apparatus  100  is present in the same subnet as the IP address of the broadcast receiving apparatus  100 , and may be prohibited when the IP address of the external equipment is outside the subnet in which the IP address of the broadcast receiving apparatus  100  is present. 
     Video and audio output for viewing contents stored in the storage (accumulation) unit  110  of the broadcast receiving apparatus  100  is allowed in principle only when the IP address of the external equipment which is the destination of a transmission packet sent from the broadcast receiving apparatus  100  is present in the same subnet as the IP address of the broadcast receiving apparatus  100 , and the output is prohibited when the IP address of the external equipment is outside the subnet in which the IP address of the broadcast receiving apparatus  100  is present. However, when the external equipment is connected within a given period in the subnet in which the IP address of the broadcast receiving apparatus  100  is present and is registered (by paring) as equipment allowed to view the contents even outside the subnet in which the IP address of the broadcast receiving apparatus  100  is present, video and audio output for viewing the contents stored in the storage (accumulation) unit  110  of the broadcast receiving apparatus  100  to the external equipment may be allowed even when the IP address of the external equipment is outside the subnet in which the IP address of the broadcast receiving apparatus  100  is present. In this case, the video and audio output for viewing the contents is performed by encoding the contents. 
     According to the process described above, different processes are performed depending on whether the IP address of the external equipment is present in the same subnet as the IP address of the broadcast receiving apparatus  100  or is outside the same subnet, so that both of the user convenience and contents protection can be achieved. 
     Next, as described above with reference to  FIG.  6 E , in the digital broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment, data that is acquired from a path (IPv4, IPv6, MPEG2-TS, URL, etc.) different from data that is acquired from a TLV stream of the broadcasting path may be included in the same package and the same event as the data that is acquired from the TLV stream based on the location information (“MMT_general_location_info( )” of  FIG.  17   ) in the MTP. The contents protection that is performed when copy control information is included in the MPT in this case will be described. 
     First, when copy control information is included in the MPT, data that is included in the same package and the same event based on the location information may be controlled in accordance with the copy control information included in the TLV stream even if the data is acquired from a path (IPv4, IPv6, MPEG2-TS, URL, etc.) different from data that is acquired from a TLV stream of the broadcasting path. As described above, the copy control states of contents specified by the copy control information include “freely copiable” (which may be divided into two types such as “freely copiable and requiring encoding process upon storage and output” and “freely copiable and not requiring encoding process upon storage and output”), “copiable only for one generation”, “copiable given times” (e.g., a so-called “dubbing  10 ” if copiable nine times+allowing move once), and “copy prohibited”. 
     Herein, if data location indicated by the location information includes MPEG2-TS data transmitted by a different digital broadcasting signal, the transmitted MPEG2-TS data is correlated with copy control information also in the different digital broadcasting signal. Accordingly, a problem arises as to in what way and in accordance with which information the copy control of the MPEG2-TS data should be performed (which of the copy control information included in the TLV/MMT stream and the copy control information included in the MPEG2-TS should be referred to in performing copy control). 
     In the digital broadcasting system of the present embodiment, this problem can be solved by performing any one of the following operations in the broadcast receiving apparatus  100 . 
     &lt;First Operation Example&gt; 
     In a first operation example, when copy control information is included in the MPT and data that is included in the same package and the same event based on the location information includes MPEG2-TS data transmitted by a different digital broadcasting signal, priority is given to a copy control state indicated by the copy control information included in the TLV stream over a copy control state indicated by the copy control information included in the MPEG2-TS in performing copy control. 
     For example, when the copy control state indicated by the copy control information included in the TLV stream is “copiable only for one generation” while the copy control state indicated by the copy control information included in the MPEG2-TS is “copiable given times”, even the data acquired from a path (digital broadcasting in the MPEG2-TS transmission format) different from the data acquired from the TLV stream may be subjected to copy control as the data contents of “copiable only for one generation”. For example, when the copy control state indicated by the copy control information included in the TLV stream is “freely copiable” while the copy control state indicated by the copy control information included in the MPEG2-TS is “copiable given times”, even the data acquired from a path (digital broadcasting in the MPEG2-TS transmission format) different from the data acquired from the TLV stream may be subjected to copy control as the data contents of “freely copiable”. 
     By this operation, data acquired from a path other than the TLV stream can also be put in a copy control state desired in the broadcasting system compatible with the broadcast receiving apparatus  100  of the present embodiment. 
     &lt;Second Operation Example&gt; 
     In a second operation example, when copy control information is included in the MPT and data that is included in the same package and the same event based on the location information includes MPEG2-TS data transmitted by a different digital broadcasting signal, a copy control state indicated by the copy control information included in the TLV stream is compared with a copy control state indicated by the copy control information included in the MPEG2-TS, and if the copy control state indicated by the copy control information included in the MPEG2-TS is severer than the copy control state indicated by the copy control information included in the TLV stream, the MPEG2-TS data is excluded from contents to be processed when performing the storing process to the storage (accumulation) unit  110 , recording process on the removable recoding medium, or outputting process from the digital interface. 
     By this operation, with respect to the data acquired from the path other than the TLV stream, the original copy control information of the data set in the broadcasting system in which the data is transmitted is taken into account, and also the redundant copy control states on the broadcast receiving apparatus  100  of the present embodiment can be eliminated. 
     Further, if the copy control state indicated by the copy control information included in the MPEG2-TS is identical to or less severe than the copy control state indicated by the copy control information included in the TLV stream as a result of the above comparison, the MPEG2-TS data that is included in the same package and the same event based on the location information may be subjected to copy control as contents in the copy control state indicated by the copy control information included in the TLV stream. 
     By this operation, with respect to the data acquired from the path other than the TLV stream, the original copy control information of the data set in the broadcasting system in which the data is transmitted is taken into account, and the redundant copy control states on the broadcast receiving apparatus  100  of the present embodiment can be eliminated. 
     The copy right protection function of the broadcast receiving apparatus  100  of the present embodiment has been described as being performed based on the copy control information included in the MPT. However, the MPT is not the only table including the copy control information. The copy control information may be included also in tables other than the MPT such as the MH-service description table (MH-SDT), the MH-event information table (MH-EIT), or other tables shown in  FIG.  6 B , and the broadcast receiving apparatus  100  can perform the copy right protection process in accordance with the copy control information transmitted in these tables. 
     According to the above-described embodiment, it is possible to provide the broadcasting receiver supporting MMT digital broadcasting. 
     Second Embodiment 
     A second embodiment of the present invention will be described below. Constituent elements, processes, effects and the like of the second embodiment are the same as those of the first embodiment unless otherwise specified. For this reason, in the following description, differences between the first embodiment and the second embodiment are mainly described, and description of the matters common to both embodiments is omitted as much as possible in order to avoid redundant description. Further, the following description will be made based on the assumption that a broadcast receiving apparatus of the second embodiment is a television receiver that supports both of MMT method and MPEG2-TS method as the media transport method. 
     [Hardware Configuration of Broadcast Receiving Apparatus] 
       FIG.  24    is a block diagram showing an example of an internal configuration of a broadcast receiving apparatus  800 . The broadcast receiving apparatus  800  includes a main control unit  801 , a system bus  802 , a ROM  803 , a RAM  804 , a storage unit  810 , a LAN communication unit  821 , an extension interface unit  824 , a digital interface unit  825 , a first tuner/demodulating unit  831 , a second tuner/demodulating unit  832 , an MMT decode processing unit  841 , an MPEG2-TS decode processing unit  842 , a video synthesizing unit  861 , a monitor unit  862 , a video output unit  863 , an audio synthesizing unit  864 , a speaker unit  865 , an audio output unit  866 , and an operation input unit  870 . 
     The main control unit  801 , the system bus  802 , the ROM  803 , the RAM  804 , the storage unit  810 , the extension interface unit  824 , the digital interface unit  825 , the monitor unit  862 , the video output unit  863 , the speaker unit  865 , the audio output unit  866 , the operation input unit  870 , and the like have functions equivalent to those of the main control unit  101 , the system bus  102 , the ROM  103 , the RAM  104 , the storage (accumulation) unit  110 , the extension interface unit  124 , the digital interface unit  125 , the monitor unit  162 , the video output unit  163 , the speaker unit  165 , the audio output unit  166 , the operation input unit  170 , and the like in the broadcast receiving apparatus  100  of the first embodiment, respectively, and detail descriptions thereof are omitted. 
     The first tuner/demodulating unit  831  receives broadcast waves of a broadcasting service adopting the MMT method as the media transport method via an antenna (not shown), and tunes to (selects) a channel giving a service that the user wishes to have, under the control by the main control unit  801 . Further, the first tuner/demodulating unit  831  demodulates a received broadcasting signal to acquire an MMT data string, and outputs the MMT data string to the MMT decode processing unit  841 . The second tuner/demodulating unit  832  receives broadcast waves of a broadcasting service adopting the MPEG2-TS method as the media transport method via an antenna (not shown), and tunes to (selects) a channel giving a service that the user wishes to have, under the control by the main control unit  801 . Further, the second tuner/demodulating unit  832  demodulates a received broadcasting signal to acquire an MPEG2-TS data string, and outputs the MPEG2-TS data string to the MPEG2-TS decode processing unit  842 . 
     The MMT decode processing unit  841  receives the MMT data string output from the first tuner/demodulating unit  831 , and performs processes of separating and decoding a video data string, an audio data string, a caption data string, a subtitle data string, and the like, which are real-time presentation elements, based on a control signal included in the MMT data string. The MMT decode processing unit  841  has the functions equivalent to those of the separating unit  132 , the video decoder  141 , the video color gamut conversion unit  142 , the audio decoder  143 , the caption decoder  144 , the subtitle decoder  145 , the subtitle synthesizing unit  146 , the subtitle color gamut conversion unit  147 , the data decoder  151 , the cache unit  152 , the application control unit  153 , the browser unit  154 , the application color gamut conversion unit  155 , the sound source unit  156 , and the like in the broadcast receiving apparatus  100  of the first embodiment. The MMT decode processing unit  841  is capable of performing the various processes described in the first embodiment. The details of the various processes have been described in the first embodiment, and further descriptions thereof are omitted. 
     The MPEG2-TS decode processing unit  842  receives the MPEG2-TS data string output from the second tuner/demodulating unit  832 , and performs processes of separating and decoding a video data string, an audio data string, a caption data string, a subtitle data string, and the like, which are real-time presentation elements, based on a control signal included in the MPEG2-TS data string. The MPEG2-TS decode processing unit  842  has the function equivalent to that of an IRD (Integrated Reviver Decoder) of a conventional television receiver that receives broadcast waves of a broadcasting service adopting the MPEG2-TS method as the media transport method, and detailed descriptions thereof are omitted. 
     The video synthesizing unit  861  receives video information, subtitle information, and application information output from the MMT decode processing unit  841  and video information, subtitle information, and application information output from the MPEG2-TS decode processing unit  842 , and properly performs a selection process and/or a superposition process. The video synthesizing unit  861  has a video RAM (not shown), and the monitor unit  862  and others are driven based on video information and others inputted to the video RAM. In addition, the video synthesizing unit  861  performs a scaling process, a superposing process of EPG screen information, and others under the control by the main control unit  801  when necessary. The audio synthesizing unit  864  receives audio information output from the MMT decode processing unit  841  and audio information output from the MPEG2-TS decode processing unit  842 , and properly performs a selection process and/or a mixing process. 
     The LAN communication unit  821  is connected to the Internet  200  via the router device  200   r , and transmits and receives data to and from server devices and other communication equipment on the 
     Internet  200 . Further, the LAN communication unit  821  acquires an MMT data string (or part of it) and an MPEG2-TS data string (or part of it) of a program transmitted through the communication line, and properly outputs them to the MMT decode processing unit  841  and the MPEG2-TS decode processing unit. 
     [Time Display in Broadcast Receiving Apparatus] 
     The broadcast receiving apparatus  800  of the present embodiment can display the current date and current time on the EPG screen and other various setting screens. Information related to the current date and current time is transmitted by an MH-TOT or the like in the case of a broadcasting service adopting the MMT method as the media transport method, and the information is transmitted by a TOT (Time Offset Table) or the like provided in SI (Service Information) defined in the MPEG-2 system in the case of a broadcasting service adopting the MPEG2-TS method as the media transport method. The broadcast receiving apparatus  800  can acquire the information related to the current date and current time by referring to the MH-TOT and the TOT. 
     In general, when the video synthesizing unit  861  mainly selects video information and others output from the MMT decode processing unit  841 , the video synthesizing unit  861  superposes the information related to the current date and current time acquired from the MH-TOT on the video information and others, and when the video synthesizing unit  861  mainly selects video information and others output from the MPEG2-TS decode processing unit  842 , the video synthesizing unit  861  superposes the information related to the current date and current time acquired from the TOT on the video information and others. 
     However, since the broadcasting service adopting the MMT method as the media transport method is different from the broadcasting service adopting the MPEG2-TS method as the media transport method in coding/decoding processes, transmission paths, and the like, there is a possibility that inconsistency occurs in current time display between the case of selecting the broadcasting service adopting the MMT method as the media transport method and the case of selecting the broadcasting service adopting the MPEG2-TS method as the media transport method. For example, when an EPG screen  162   g  displaying channel information of the broadcasting service adopting the MMT method as the media transport method is switched to an EPG screen  162   h  displaying channel information of the broadcasting service adopting the MPEG2-TS method as the media transport method as shown in  FIG.  25   , the inconsistency caused when the display of current time is switched from a current time display  162   g   1  to a current time display  162   h   1  may give the user a feeling of visual discomfort. 
     In order to prevent the user from having such a feeling of visual discomfort, the broadcast receiving apparatus  800  of the present embodiment performs control to superpose the information related to the current date and current time acquired from the TOT on the video information and others even when the video synthesizing unit  861  mainly selects the video information and others output from the MMT decode processing unit  841 . Namely, the broadcast receiving apparatus  800  of the present embodiment performs control to superpose current time information provided by the broadcasting service adopting the MPEG2-TS method as the media transport method, on the contents of the broadcasting service adopting the MMT method as the media transport method. 
     Through the control described above, the broadcast receiving apparatus  800  of the present embodiment always displays the current time information that is acquired by referring to the TOT. Thus, even when the broadcasting service adopting the MMT method as the media transport method and the broadcasting service adopting the MPEG2-TS method as the media transport method are switched to each other, it is possible to prevent the user from having such a feeling of visual discomfort due to inconsistency in the display of current time. 
       FIG.  26 A  shows an example of selection control of a reference source of current time information in accordance with the reception state of broadcasting services in the broadcast receiving apparatus  800  of the present embodiment. The broadcast receiving apparatus  800  of the present embodiment always refers to the TOT to acquire current time information when the broadcast receiving apparatus  800  is in a condition in which it can receive the broadcasting service adopting the MPEG2-TS method as the media transport method, and refers to the MH-TOT to acquire current time information only when the broadcast receiving apparatus  800  is in a condition in which it cannot receive the broadcasting service adopting the MPEG2-TS method as the media transport method but can receive the broadcasting service adopting the MMT method as the media transport method. 
     In addition, the above-mentioned effect can be achieved also by performing control to superpose current time information provided by the broadcasting service adopting the MMT method as the media transport method on contents of the broadcasting service adopting the MPEG2-TS method as the media transport method contrary to the above control. 
     In both of the case of control in which current time information provided by the broadcasting service adopting the MPEG2-TS method as the media transport method is superposed on contents of the broadcasting service adopting the MMT method as the media transport method and the case of control in which current time information provided by the broadcasting service adopting the MMT method as the media transport method is superposed on contents of the broadcasting service adopting the MPEG2-TS method as the media transport method, the current time information can be corrected by referring to the “delta” parameter of the time information in the TMCC extension information region as described above in [Time Management of Broadcast Receiving Apparatus] of the first embodiment. 
     Further, in both cases of the broadcasting service in which the MMT method is adopted as the media transport method and the broadcasting service in which the MPEG2-TS method is adopted as the media transport method, there is a possibility that the MH-TOT or TOT transmitted by respective broadcasting services making up the network has an error due to the fault of the transmission system or the transmission failure. As the measures for the error of the MH-TOT or TOT described above, the broadcast receiving apparatus  800  of the present embodiment has a function of performing an update process of time information of a built-in clock by acquiring an MH-TOT or 
     TOT from a different broadcasting service in the same network or an arbitrary broadcasting service in another network and referring to current time information of the acquired MH-TOT or TOT when it is determined that the MH-TOT or TOT acquired from the service being received at present has an error. 
       FIG.  26 B  shows an example of an update process of current time information in the case where the broadcasting service adopting the MPEG2-TS method as the media transport method is received in the broadcast receiving apparatus  800  of the present embodiment. Note that the process similar to that shown in  FIG.  26 B  is possible even when the broadcasting service adopting the MMT method as the media transport method is received. 
     When the time information of the built-in clock is updated in the broadcast receiving apparatus  800  of the present embodiment, first, the receiving function executing unit  1102  acquires the TOT from the MPEG2-TS data string of the currently received broadcasting service (broadcasting serving adopting the MPEG2-TS method as the media transport method) (S 301 ), and then acquires the current time information by referring to the acquired TOT (S 302 ). Next, the receiving function executing unit  1102  performs the process of comparing the current time information acquired in the process of S 302  and the time information of the built-in clock. 
     When the difference between the current time information acquired in the process of S 302  and the time information of the built-in clock is within a given value (e.g., within 3 minutes) as a result of the comparison process (S 303 : Yes), the receiving function executing unit  1102  updates the time information of the built-in clock based on the current time information acquired in the process of S 302  (S 306 ). Meanwhile, when the difference between the current time information acquired in the process of S 302  and the time information of the built-in clock is not within the given value as a result of the comparison process (S 303 : No) or the TOT acquired in S 301  has a flag or the like indicating that an error is present in the data, the receiving function executing unit  1102  acquires a TOT from an MPEG2-TS data string of a different broadcasting service in the same network or acquires an MH-TOT from an MMT data string of an arbitrary broadcasting service (broadcasting serving adopting the MMT method as the media transport method) in another network (S 304 ), and further acquires current time information from the acquired TOT or MH-TOT (S 305 ). The receiving function executing unit  1102  can perform the comparison process of S 303  again based on the current time information acquired in the process of S 305 . 
     Through the process described above, the broadcast receiving apparatus  800  of the present embodiment can perform the update process of the time information of the built-in clock by acquiring an MH-TOT or TOT from a different broadcasting service in the same network or an arbitrary broadcasting service in another network and referring to current time information of the acquired MH-TOT or TOT when it is determined that the MH-TOT or TOT acquired from the service being received at present has an error. 
     When the current time information whose difference from the time information of the built-in clock falls within a given range cannot be acquired even by the repetition of S 304  and S 305  like in the initial setting after the product shipment, the time information of the built-in clock may be set newly based on the current time information acquired in the process of S 302 . In this manner, it is possible to deal with the case where the time information of the built-in clock of the broadcast receiving apparatus  800  of the present embodiment has an error. 
     [Display of EPG in Broadcast Receiving Apparatus] 
     Event schedule information of the broadcasting service adopting the MMT method as the media transport method is transmitted by MH-EIT or the like. Meanwhile, event schedule information of the broadcasting service adopting the MPEG2-TS method as the media transport method is transmitted by EIT (Event Information Table) or the like included in SI defined in the MPEG-2 system. Therefore, in general, when video information or the like provided by the broadcasting service adopting the MMT method as the media transport method is displayed, the event schedule information (MH-EIT) of the broadcasting service adopting the MMT method can be acquired, and when video information or the like provided by the broadcasting service adopting the MPEG2-TS method as the media transport method is displayed, the event schedule information (EIT) of the broadcasting service adopting the MPEG2-TS method can be acquired. 
     However, the broadcast receiving apparatus  800  of the present embodiment can acquire both MH-EIT and EIT when displaying video information or the like provided by the broadcasting service adopting the MMT method as the media transport method as well as when displaying video information or the like provided by the broadcasting service adopting the MPEG2-TS method as the media transport method, and thus the user friendliness can be improved. 
       FIG.  27 A  shows an example of the EPG screen in the broadcast receiving apparatus  800  of the present embodiment. In  FIG.  27 A , an EPG screen  162   i  is an EPG screen that is created based on the MH-EIT of the broadcasting service adopting the MMT method as the media transport method, and “M1 television”, “M2 broadcasting”, “M3 channel”, “M4 TV”, “television M5” and the like are the names of broadcast stations that provide the broadcasting service adopting the MMT method as the media transport method. Further, an EPG screen  162 j is an EPG screen that is created based on the EIT of the broadcasting service adopting the MPEG2-TS method as the media transport method, and “T6 television”, “T7 broadcasting”, “T8 channel”, “T9 TV”, “television TA” and others are the names of broadcast stations that provide the broadcasting service adopting the MPEG2-TS method as the media transport method. 
     For example, when the user who is watching a broadcasting program provided by the broadcasting service adopting the MMT method as the media transport method gives an instruction to display the EPG screen by operating the remote controller (not shown), an initial EPG screen (not shown) appears. The initial EPG screen is an EPG screen that is created based on the MH-EIT of the broadcasting service adopting the MMT method as the media transport method, and shows detailed information of broadcasting programs of respective channels in a time zone of “from 17:00 (around current time)” on “October 7, 2014 (today)”. Then, if the user wishes to check detailed information of broadcasting programs of respective channels in a time zone of “from 20:00” on “October 9, 2014” and gives an instruction to update the EPG screen by operating the remote controller (not shown), the EPG screen  162   i  appears. 
     Subsequently, if the user wishes to check detailed information of broadcasting programs provided by the broadcasting service adopting the MPEG2-TS method as the media transport method and gives a network switching instruction by operating the remote controller (not shown), the EPG screen  162   j  appears. At this time, the broadcast receiving apparatus  800  of the present embodiment controls the screen to display detailed information of broadcasting programs of the respective channels in the same time zone on the same date (i.e., “from 20:00” on “October 9, 2014”) as those of the EPG screen  162   i  displayed just before the network switching, instead of the initial EPG screen that is created based on the EIT of the broadcasting service adopting the MPEG2-TS method as the media transport method (i.e., detailed information of broadcasting programs of the respective channels in the time zone of “from 17:00” on “October 7, 2014”). 
     Through the control described above, the user can consecutively check detailed information of broadcasting programs provided in the same time zone on the same date by a plurality of networks with different media transport methods by a simple operation. Namely, the user friendliness of the broadcast receiving apparatus  800  can be improved. 
       FIG.  27 B  is a diagram showing an example of the EPG screen in the broadcast receiving apparatus  800  of the present embodiment that is different from the example mentioned above. An EPG screen  162   k  shows a state obtained by scrolling the EPG screen  162   i  of  FIG.  27 A  in the direction of arrangement of the channels (horizontal direction) by the operation of the remote controller (not shown). Namely, in the example of  FIG.  27 B , by scrolling the EPG screen in the direction of arrangement of the channels (horizontal direction), the channel information that is created based on the MH-EIT of the broadcasting service adopting the MMT method as the media transport method and the channel information that is created based on the EIT of the broadcasting service adopting the MPEG2-TS method as the media transport method are displayed on the same time axis in a seamless manner. 
     Accordingly, even when the user wishes to check the channel information that is created based on the EIT of the broadcasting service adopting the MPEG2-TS method as the media transport method while checking the channel information that is created based on the MH-EIT of the broadcasting service adopting the MMT method as the media transport method, the user does not need to give a network switching instruction or the like by the operation of the remote controller (not shown). In addition, the user is allowed to collectively check detailed information of broadcasting programs provided in the same time zone on the same date by a plurality of networks with different media transport methods. Namely, the user friendliness of the broadcast receiving apparatus  800  can be improved. 
     Third Embodiment 
     Hereinafter, a third embodiment of the present invention will be described. Constituent elements, effects and the like according to the present embodiment are the same as those of the first and second embodiments unless otherwise specified. For this reason, in the following description, differences between the present embodiment and the first and second embodiments are mainly described, and description of the matters common to the embodiments is omitted as much as possible in order to avoid redundant description. In the present embodiment, treatment of presentation region information set by a layout configuration table (LCT) shown in  FIG.  18    will be described. 
     [Hardware Configuration of Broadcast Receiving Apparatus] 
     A hardware configuration of a broadcast receiving apparatus  100  is the same as that in the first embodiment. Thus, its explanation will be omitted. 
     [Structure of Broadcast Data] 
       FIG.  28    shows a structure of broadcast data. The broadcast data are made up of information to be presented to the broadcast receiving apparatus  100  (an asset  30003 ), such as videos, audios, and program-cooperation information, and control information. Note that character information, graphic information, image information, video information or the like to be presented together with a program video is stored in the program-cooperation information.  FIG.  28    shows a method of presenting the asset  30003  and a PA message  30000  in which acquisition destination information is described of the control information. An acquisition destination of the asset  30003  is described in an MP table (MPT)  30001  ( FIG.  17   ) within the PA message  30000  ( FIG.  30   ) as MMT_general_location_info ( FIG.  31   ). Further, a layout configuration table (LCT)  30100  ( FIG.  18   ) is arranged in the PA message  30000 , and a layout of regions to which the assets  30003  are respectively presented.  FIG.  19 A  to  FIG.  19 D  show examples of a layout of a presentation region. 
     A package list table (PLT)  30002  ( FIG.  32   ) is arranged in the PA message  30000 , and an acquisition destination of another PA message  30000  can be described in the PLT by MMT_general_location_info ( FIG.  31   ). This specification of the acquisition destination of the PA message  30000  allows the PA message  30000  to have a hierarchical structure.  FIG.  33    shows location types of the acquisition destination of the PA message  30000  and the asset  30003 . 
     The hierarchical structure of the PA message  30000  may take two layers as shown in  FIG.  28   . However, by further arranging a PLT  30002  on the PA message  30000  of a second layer, it is possible to increase the layers thereof. 
     The asset is composed of a Media Processing Unit (MPU) that becomes a process unit (transaction) ( FIG.  29   ). Thus, by specifying a presentation region of an MPU in an MPU presentation region specifying descriptor ( FIG.  34   ), a presentation region of the asset  30003  is specified. The MPU presentation region specifying descriptor is arranged in an asset descriptor region of the MPT. Since a presentation region is specified for every MPU, a presentation method of changing a presentation region of the same asset  30003  in the middle of the presentation is available. In order to reduce the amount of data, a control method of specifying only a presentation region of an MPU at the head of a group of MPUs for which a presentation region is to be changed without specifying presentation regions of all MPUs that belong to the asset is available. 
     [Operation Examples of Asset Presentation] 
     &lt;First Operation Example&gt; 
     The broadcast receiving apparatus  100  obtains presentation region information by reading the LCT  30100 .  FIG.  16    shows, as an example of the time when to change channels, a flow in which the broadcast receiving apparatus  100  obtains control information of a program. The LCT  30100  is transmitted while being arranged in an MMTP packet in the similar manner. Since specification information of the presentation region of the asset  30003  is described in the MPT  30001 , it is preferable that the LCT  30100  is obtained before obtaining the MPT  30001 . In the example shown in  FIG.  16   , it is preferable that it is obtained at a Step between S 209  and S 210  and a Step between S 214  and S 215 . It is similarly preferable that the LCT can be obtained before S 216  even in a case where it cannot be obtained at the timing. 
     The LCT  30100  is arranged in the PA message  30000 . However, the LCT  30100  regarding the asset  30003 , which corresponds to the PA message of the second layer, is arranged in the PA message  30000  of a first layer or the PA message  30000  of the second layer. In presentation of the asset  30003 , presentation region information of the LCT  30100  that is arranged in the PA message  30000  to which the asset  30003  as a presentation target belongs is preferentially used. In a case where the LCT  30100  is not arranged in the belonging PA message  30000 , presentation region information of the LCT  30100  that is arranged in the PA message  30000  of the upper layer is used. 
     By using the method of this operation example, in a case where the same LCT  30100  is used for the whole broadcast data in  FIG.  28   , it is possible to obtain the presentation region information at earlier timing so long as the common LCT  30100  is arranged in the PA message  30000  of the first layer. Therefore, it is possible to present the broadcast data quickly. 
     &lt;Second Operation Example&gt; 
     In a case where the LCT  30100  is not included in the MMTP packet, the presentation region information of the LCT  30100  that has been obtained is used. In other words, the broadcast receiving apparatus stores the presentation region information of the LCT  30100 , and updates the stored presentation region information whenever a new LCT  30100  is obtained. 
     However, immediately after an event, which the presentation region information that has been used becomes unavailable, such as when to turn on the broadcast receiving apparatus  100  and when to change channels, there is no effective presentation region information yet. Thus, even though video data and audio data of a program are obtained, there is a possibility that the data cannot be presented. For that reason, a presentation process is executed until effective presentation region information is obtained so that a presentation region shown in  FIG.  19 A  is set as tentative presentation region information, for example. Hereinafter, the settings of  FIG.  19 A  are referred to as “default settings”. As the presentation region shown in the default settings ( FIG.  19 A ), a region of full screen display is set to a device whose Device_id is “0”, that is, a main device, and “0” is assigned to each of layout_number, region_number, and layer_order. 
       FIG.  35 A  shows a state that only a main asset  30201  is presented by using the tentative presentation region information, and  FIG.  35 B  shows a state that after the LCT  30100  is obtained, presentation is executed so as to include a sub asset  30202  in accordance with the presentation region information inherent in the program. In a case where the tentative presentation region information is used, presentation region specification for the main asset is ignored; a region to each of whose layout_number and region_number is “0” is specified; and presentation for the other assets is not executed. Here, the main asset means an asset in which “0” is specified as the region_number of the main device, or an asset that is transmitted by the broadcast waves and in which “0” is specified as the region_number. The sub asset means the other assets. 
     By setting the tentative presentation region information in this manner, it becomes possible to execute at least the presentation process for the main asset even before information on the LCT  30100  is read. 
     &lt;Third Operation Example&gt; 
     In the second operation example, an example in which when to change channels or the like, only a main asset is presented by using default presentation region information until a new LCT  30100  is obtained has been described. However, an LCT  30100  used in a program that has been viewed may be used. An asset (main asset) specified to a region whose region_number is “0” in the program after channels are changed is presented to a region whose region_number is “0” in the presentation region information that has been used, and the other assets (sub asset) are not displayed. 
     After the LCT  30100  of the program after changing the channels is obtained, presentation of all assets is executed by using the presentation region information. Further, in a case where the LCT  30100  used in the program that has been viewed is one in which a display region is divided as shown in  FIG.  19 B , the process of the second operation example may be executed. In a case where the LCT  30100  used in the program that has been viewed is one in which they are overlaid and displayed as shown in  FIG.  19 C , the process of the third operation example may be executed. Further, in a case where the LCT  30100  used in the program that has been viewed has a region whose region_number is 1 or more, a predetermined pattern or message or the like may be displayed in the region. 
     By using the presentation region information of the program that has been viewed in this manner, it becomes possible to execute the presentation process for at least the main asset even before information of the LCT  30100  is read. 
     &lt;Fourth Operation Example&gt; 
     The channel may be returned to the former channel after the channels are changed. Thus, a method of storing information of the 
     LCT  30100  that has been read once so as to be associated with channel information and using stored presentation region information when to return to the former channel may be adopted. Note that by storing the latest LCT  30100  for each of all channels that the broadcast receiving apparatus  100  can receive, convenience regarding the presentation region control when to change channels is improved. 
     Further, the presentation region information may be changed even in the middle of the program. Thus, an expiration date is set to the LCT  30100 . In a case where the expiration date has passed at the time when the channel is returned, the presentation region information is not used, and only the main asset is presented by the method shown in the second operation example or the third operation example by using default settings or the presentation region information of the program that has been viewed. Alternatively, only the main asset may be presented by using the presentation region information of the channel whose expiration date has passed. After a new LCT  30100  is obtained, it is of course returned to a normal presentation method. Note that the control may be executed by referring to the expiration date, but may be executed by referring to a version thereof instead of information on the expiration date. 
       FIG.  36 A  shows an example in which an expiration date is set to the LCT  30100 . The expiration date is set into an LCT expiration date descriptor in an NTP-length format (ending_time). The descriptor is arranged in a descriptor region of the LCT  30100  ( FIG.  18   ). 
     Alternatively, as shown in  FIG.  36 B  as the layout expiration date descriptor, an expiration date may be set for each layout. 
     Alternatively, as shown in  FIG.  36 C  as the presentation region expiration date descriptor, an expiration date may be set for each region. 
     The expiration date may be set with a single layer, or the expiration date may be set with a plurality of layers. When the expiration date is set with the plurality of layers, an earlier expiration date is prioritized for each region. 
     This method allows the presentation region information that has been obtained once to be utilized effectively while taking into consideration the expiration date. 
     &lt;Fifth Operation Example&gt; 
     In the fourth operation example, the presentation region information of the program that has been read once is stored. However, a method of preparing presentation region information commonly used in a plurality of programs of a channel (common presentation region information) for each channel, obtaining the common presentation region information in advance by the broadcast receiving apparatus  100 , and using the common presentation region information for each program may be adopted. 
     The common presentation region information is obtained in advance by the broadcast receiving apparatus  100  in form of an LCT ( FIG.  18   ). In order to indicate that it is the common presentation region information, a common presentation region information descriptor shown in  FIG.  37    is used. This descriptor is arranged in a descriptor region of the LCT ( FIG.  18   ), and a layout number that is a common presentation region is cited together with a device number. Service_id indicates a channel of broadcast. Moreover, a beginning time (beginning_time) and an ending time (ending_time) of an effective period of time of the common presentation region information is described in the NTP-length format. Further, full_set_flag is also described so as to be capable of confirming that all information is completed when to update the information. Meanings of full_set_flag are collected in  FIG.  38   . 
     This common presentation region information may be read during a time zone outside the broadcasting time at a cycle, such as once a day or once a week, for example. Further, it may be obtained from the broadcast waves, or may be obtained via the Internet. 
     For the purpose of the case where the common presentation region information has not been read, common presentation region information to be used in the program is transmitted as the LCT  30100  in the broadcast. At that time, full_set_flag of the common presentation region information descriptor indicates that it is partial information of the common presentation region information. 
     By this common presentation region information, it is possible to execute presentation of the asset  30003  rapidly even at timing before obtaining the LCT  30100  immediately after turning on the broadcast receiving apparatus  100  or immediately after switching programs. 
     &lt;Sixth Operation Example&gt; 
     The method of using the common presentation region information has been described in the fifth operation example. However, a presentation region for a layout, which is not described in common presentation region information, may be used depending upon a program even though common presentation region information is a channel that is transmitted by broadcast waves or via the Internet. 
     Specifically, the information on the layout that is not described in the common presentation region information may be described by the LCT  30100  of the program. A layout number that is a common presentation region is described by the common presentation region information descriptor ( FIG.  37   ) at that time. Thus, the broadcast receiving apparatus  100  grasps whether there is additional presentation region information that is not the common presentation region in the LCT  30100  or not. In a case where there is one, the broadcast receiving apparatus  100  uses that information. At this time, in a case where there is one in which a layout number and a region number of the presentation region are duplicated with those of the common presentation region information, which information is to be prioritized is defined in advance. Namely, depending upon one broadcasting system, the broadcast receiving apparatus  100  may be configured to prioritize the common presentation region information. Further, depending upon another broadcasting system, the broadcast receiving apparatus  100  may be configured to prioritize the presentation region information of an individual program. 
     Moreover, in a case where the common presentation region information descriptor ( FIG.  37   ) is not arranged in the LCT  30100 , the presentation region information described in the LCT  30100  is dealt with as a situation to specify that all is not the common presentation region information. 
     Note that the additional presentation region information for this individual program may be obtained from the broadcast waves. It may not be obtained from the broadcast waves, but may be obtained via the Internet. 
     According to this method, it is possible to use the presentation region information optimized for each program while using the common presentation region information. 
     &lt;Seventh Operation Example&gt; 
     Presentation of the asset  30003  is executed for one presentation region. However, in a case where it is better to be displayed on as many terminals as possible like a news bulletin, the same content may be presented to all available terminals at that time. 
     As a concrete method, in a duplicative presentation region specifying descriptor ( FIG.  39   ), layout_number for which the same region setting is also executed in other device is described among layout settings of the main device (the device whose Device_id is “0”). This descriptor is arranged in a descriptor region of the LCT  30100  ( FIG.  18   ). 
       FIG.  40    shows an example in which a screen with the same content is presented on a sub device (a portable information terminal  700 ) in addition to the main device (the broadcast receiving apparatus  100 ). 
     For the purpose of a situation that the program is returned to a former program after the news bulletin ends, presentation region information used for the former program may be stored, and that information may be used after the news bulletin ends. 
     This method allows to improve recognizability of important information with high urgency. 
     &lt;Eighth Operation Example&gt; 
     Layout_number (layout number) and region_number (region number) are specified by an MPU presentation region specifying descriptor ( FIG.  34   ), whereby a presentation region of each of the assets  30003  is specified. In a case where there is no presentation region information corresponding to the layout number and the region number, it cannot be presented. Therefore, presentation of the asset  30003  is not executed. Thus, in a case where an asset  30003  with abnormality is to be presented in a partial region of a screen, its display abnormality may not be recognized at a glance. Therefore, in a case where the asset  30003  that cannot be presented occurs, an error display as shown in  FIG.  41    is executed. 
     This method allows a viewer to recognize that the display is not executed in a normal way. 
     &lt;Ninth Operation Example&gt; 
     In the eighth operation example, an operation in a case where a presentation region with no presentation region information is specified has been explained. However, an operation of the case where different assets  30003  specify the same presentation region will be described. In the case of an asset for executing display of given contents, the contents cannot be displayed in the same presentation region. Thus, for different assets  30003 , the same presentation region must not be specified at the same time. If they are specified at the same time, the asset that is transmitted via broadcast waves is prioritized. Alternatively, presentation of the asset  30003  that previously uses the layout number and the region number continues, and presentation of the asset  30003  for which they are then specified is prohibited. Alternatively, presentation of all of the assets  30003  for which specification of the region is duplicated is prohibited. In a case where the asset  30003  that cannot be presented occurs, the error display as shown in  FIG.  41    may be executed. 
     However, it could be that the same presentation region is specified for different assets  30003  in the case of achieving high gradation display by adding additional information of an asset to a video asset or the like, for example. In order to indicate that a plurality of assets has a complementary relation so as to constitute one content, information of a dependency relation descriptor is used.  FIG.  42    shows a data structure of the dependency relation descriptor. 
     In a case where there is this dependency relation, presentation thereof is permitted even though the same presentation region is specified. 
     In order to manage specification of a presentation region for the asset  30003 , a management table indicating which presentation region each asset  30003  specifies may be used.  FIG.  43    shows an example of a management table. The asset  30003  of asset ID  1  and the asset  30003  of asset ID  3  respectively has a dependency relation with the asset  30003  of asset ID  2  and the asset  30003  of asset ID  4 . Thus, even though the same region is specified, display thereof is permitted. On the other hand, the asset  30003  of asset ID  7  is a video asset, has no dependency relation, and specifies the same region as asset ID  1 . Thus, presentation thereof is prohibited. 
     Note that the asset  30003  of asset ID  1  is transmitted by the broadcast waves, and thus this has priority. Further, the presentation of the asset  30003  of asset ID  7  whose acquisition destination is the same as that of the asset  30003  of asset ID  8  is prohibited. Since there is a high possibility that the asset  30003  of asset ID  7  is an audio that becomes a pair with the asset  30003  of the asset ID  8 , presentation thereof is also prohibited. Further, the assets  30003  of asset IDs  2 ,  4 ,  6 ,  8  are audio assets, and such an audio asset is not directly related to the presentation process in a monitor unit  162 . Thus, they may not be managed in the management table necessarily. Namely, only the video assets may be managed in the management table. 
     By executing a control of the presentation in this manner, it is possible to prevent abnormal presentation from being made in a case where there is inconsistency in the control information. 
     &lt;Tenth Operation Example&gt; 
     In a dependency relation of assets  30003 , there are the case where it becomes a parallel relation in which it is not completed as contents unless a plurality of assets  30003  that are dependent on each other becomes complete, and the case where it becomes a dependency relation in which data for high image quality is given to an independent asset  30003  as another asset  30003 . The independent asset  30003  can be presented independently, but the dependent asset  30003  is likely to become abnormal in presentation in a case where there is no independent asset  30003 . Thus, in a case where the asset  30003  to be depended on cannot be obtained, presentation of the dependent asset  30003  is prohibited. Note that it may take a multilayer structure so that another asset  30003  further depends on the dependent asset  30003 . 
     In order to specify a dependency relation, it may be determined in advance whether the asset  30003  described in the dependency relation descriptor ( FIG.  42   ) indicates an asset  30003  of a dependency destination or an asset  30003  depending on the present asset. In the case of the assets  30003  that has the parallel relation, the dependency relation descriptor ( FIG.  42   ) is arranged so that one of both depends on the other. 
     As another method of specifying a dependency relation, a method of clearly indicating a dependency relation in a dependency relation descriptor ( FIG.  42   ) may be used.  FIG.  44    shows a dependency relation descriptor in which a dependency relation is clearly indicated. A parameter called “dependency_type”, which indicates a type of dependency of an asset that has a dependency relation, is specified.  FIG.  45    shows meanings of the dependency type. “0” denotes the case of depending on a partner, and “1” denotes the case of being depended on by a partner. In the case of having the parallel relation, specification is executed so that each one depends on the other asset. 
       FIG.  46    shows an example of a management table for permission or prohibition of presentation. An asset of ID  3  and an asset of ID  4  are respectively depending on an asset of ID  1  and an asset of ID  2 . Since the assets of ID  1  and ID  2  are obtained, presentation thereof is permitted. On the other hand, presentation of an asset of ID  9  and an asset of ID  10  is prohibited because an asset of ID  7  and an asset of ID  8  that are respectively dependency destinations thereof are not obtained. 
     An asset of ID  11  and an asset of ID  12  have a mutual dependency relation. However, since both assets become complete, presentation thereof is permitted. On the other hand, an asset of ID  13  and an asset of ID  14  also have a mutual dependency relation, but the asset of ID  13  has not been obtained yet. Thus, presentation of the asset of ID  14  is prohibited. In a case where an asset  30003  that cannot be presented occurs, the error display as shown in  FIG.  41    may be executed. 
     By executing the control of the presentation in this manner while taking into consideration dependency relation, it is possible to prevent the abnormal presentation from being made in a case where there is inconsistency in the control information. 
     &lt;Eleventh Operation Example&gt; 
     The broadcast receiving apparatus  100  can present both an asset  30003  obtained from broadcast waves and an asset  30003  obtained from a communication line (the Internet). However, depending upon a state of the communication line, the asset  30003  via the communication line cannot be obtained, or the broadcast receiving apparatus  100  may not be connected to the communication line in the first place. Thus, only a broadcasting video of broadcast waves may normally be displayed with a full screen by using the default settings ( FIG.  19 A ), and presentation of the asset  30003  may be executed in a region specified in accordance with settings of the LCT  30100  when the asset  30003  via the communication line is obtained. 
     For example, the case where region settings of the LCT  30100  are made as shown in  FIG.  19 B  and it is set so that a broadcasting video is presented to region  0  and assets  30003  via a communication line are presented to region  1  and region  2  will be described. In a case where only the video of the broadcast waves can be received, the broadcasting video is displayed with a full screen by using the default settings ( FIG.  19 A ). At the time when it comes to a state that the asset  30003  via the communication line can be obtained, by using the region setting of the LCT  30100 , the broadcasting video is presented to the region  0  shown in  FIG.  19 B , and the asset  30003  via the communication line is presented to the region  1  and the region  2 . In this case, the LCT  30100  may not be transmitted via the broadcast waves, and may be transmitted together with the asset  30003  via the communication line. By utilizing the method of this operation example, display according to an actual reception situation of the broadcast data becomes possible. In a case where one of the assets  30003  via the communication line is completely obtained and the other is not obtained, the default settings ( FIG.  19 A ) may be maintained. It is desirable to control it so as to shift to the region setting shown in  FIG.  19 B  at the time when both of the assets  30003  via the communication line become complete. 
     Fourth Embodiment 
     Hereinafter, a fourth embodiment of the present invention will be described. Constituent elements, effects and the like according to the present embodiment are the same as those of the first to third embodiments unless otherwise specified. For this reason, in the following description, differences between the present embodiment and the first to third embodiments are mainly described, and description of the matters common to the embodiments is omitted as much as possible in order to avoid redundant description. In the present embodiment, operation examples of treatment of presentation region information set by a layout configuration table (LCT) shown in  FIG.  18    and treatment of contents other than program will be described. 
     [Hardware Configuration of Broadcast Receiving Apparatus] 
     A hardware configuration of a broadcast receiving apparatus  100  is the same as that in the first embodiment. Thus, its explanation will be omitted. 
     [Modification Operation Example of Asset Presentation] 
     &lt;First Operation Example&gt; 
     In a case where channels are to be changed by using an Electronic Program Guide (EPG), an LCT  30100  is obtained from a PA message  30000  of a new program in a state that the EPG is displayed at the stage of selecting the new program on the EPG as shown by a broken-line frame  30203  in  FIG.  47   . Thus, it becomes possible to execute a presentation process of the asset according to the presentation region information specified via the program in a state that the program is displayed. 
     Alternatively, the presentation region information of each program is incorporated in EPG data (which are ones in which various other necessary data focusing an MH-EIT obtained from broadcast waves or a communication network are stored in a storage unit such as a memory) , and presentation region information of a program to be newly changed is read from the EPG data. Therefore, it is also possible to obtain the presentation region information of the program more quickly. In this case, since another tuner may not be used, it is possible to reduce the number of tuners. 
     Alternatively, a process of distributing the presentation region information of each program via the Internet and reading the presentation region information of each program in advance may be executed. Since another tuner may also not be used in this case, it is possible to reduce the number of tuners. 
     Note that a scaled-down program video may be displayed in a slave screen  30204  when the EPG is being displayed. However, it becomes hardly viewed even though a sub asset is presented in this state. Therefore, an LCT setting for the program may be ignored, and only a main asset may be presented in the whole slave screen  30204 . It is not limited to the slave screen when to display the EPG, but in a situation that the main asset is hardly viewed due to display of the sub asset, the LCT setting may similarly be ignored. 
     &lt;Second Operation Example&gt; 
     In order to deal with viewing in the middle of a program, the LCT  30100  is repeatedly transmitted. However, in a case where the LCT  30100  has not been transmitted for a given period of time, which includes the case of stopping receiving broadcast, as presentation region setting, the receiving apparatus determines that effective presentation region information is lost, and returns to default settings ( FIG.  19 A ). In a case where the presentation region setting is changed at the time when to restart receiving, it is possible to prevent abnormal presentation due to remaining of the old presentation region setting. Since the default settings are settings to execute presentation of the main asset, presentation never becomes abnormal regardless of a program. 
     &lt;Third Operation Example&gt; 
     In a case where there is inconsistency or the like in information of the LCT  30100  used in the program and there is no effective presentation region information, the default settings ( FIG.  19 A ) are used in order to ensure display of only the main asset at the minimum. 
     &lt;Fourth Operation Example&gt; 
     In a case where there is an asset via the Internet in addition to one via the broadcast waves and asset data via the Internet can be obtained but reception of the broadcast waves is stopped, the presentation region setting is maintained for a given period of time or until setting of a new presentation region is established even though the LCT  30100  is not obtained, and presentation of the asset via the Internet is continued. This method allows presentation of an asset, which can be presented partially even in an abnormal situation, to be continued. 
     &lt;Fifth Operation Example&gt; 
     In a case where there is an asset via the Internet in addition to one via the broadcast waves and reception of the broadcast waves is continued but asset data via the Internet cannot be obtained, the presentation region setting is changed into the default settings ( FIG.  19 A ), and presentation of only the main asset is executed. For example, in a case where presentation regions for the asset via the Internet are region  1  and region  2  shown in  FIG.  19 B  and a presentation region of a broadcasting screen is region  0 , portions of the region  1  and the region  2  become a background color and are thus hardly viewed when presentation of the asset via the Internet disappears. In such a case, by using the default settings ( FIG.  19 A ) and displaying the broadcasting screen (the main asset) in a full screen, it is possible to effectively use the screen without being hardly viewed. 
     Note that, when the presentation region setting is changed to the default settings ( FIG.  19 A ) in the process described above, an error message  30205 , which indicates that data cannot be obtained from the Internet, may be displayed ( FIG.  48   ). 
     [Method of Treating Contents Other Than Program] 
     There is the case where a user wants to use the contents other than program, for example, contents or applications on the Internet while viewing a program. Processing in such a case will be described. 
     First, whether presentation of the contents other than program is permitted while viewing the program or not is set by a contents control descriptor.  FIG.  49    shows a data structure of the contents control descriptor. This descriptor is arranged in the MPT  30001  ( FIG.  17   ,  FIG.  28   ). In  FIG.  49   , a parameter called contents_control_mode (a contents control mode) denotes permission or prohibition of the presentation of the contents other than program. 
       FIG.  50    shows meanings of the contents control modes. The case of Mode  00  means prohibition thereof, and the other cases mean permission thereof. In addition, three types are provided for the permission mode. In the case of Mode  01 , presentation thereof in a specified region is permitted. Specification of the region is executed by layout_number and region_number. In the case of Mode  10 , presentation of the contents other than program is permitted so long as presentation of program contents is not interfered. In the case of Mode  11 , presentation of the contents other than program is permitted, and a presentation method is taken arbitrarily. 
       FIG.  51    shows an example of Mode  01 . The program contents are a main asset to be presented to a region  30206  and a sub asset to be presented to a region  30207 . The contents other than program is displayed in a region  30208 . Here, presentation of a web browser  30209  is shown as an example. In the example in  FIG.  51   , a presentation region of the program contents does not overlap with a presentation region of the contents other than program. However, these regions may overlap each other, and the contents other than program may be presented on the program contents. 
       FIG.  52    shows an example of Mode  10 . It shows a state where program contents  30210  and contents other than program  30209  are presented. Presentation of the program contents herein is executed as a full screen region so that a partial region of a screen  162  in the broadcast receiving apparatus is specified by the LCT  30100 . Namely, a position  30211  at the upper left of a presentation region of the program contents  30210  corresponds to a position of “left_top_pos_x=0, left_top_pos_y=0” by the LCT  30100 , and a position  30212  of the lower right thereof corresponds to a position of “right_down_pos_x=100, right_down_pos_y=100” by the LCT  30100 . Which position of the screen  162  in the broadcast receiving apparatus  100  the full screen region specified by the LCT is set to is set in advance in the broadcast receiving apparatus  100 , or is set by a viewer. The contents other than program may be presented at any position so long as presentation of the program contents is not interfered. They are presented so that they are not overlapped as the regions or presentation of the program contents is not hidden by presenting the contents other than program behind the program contents even though they are overlapped ( FIG.  53   ). 
       FIG.  54    shows an example of Mode  11 . In this case, a relation between presentation of program contents and presentation of contents other than program is arbitrary. The presentation of the contents other than program may be executed so as to hide the presentation of the program contents. 
     As explained above, since the program contents and the contents other than program can be viewed at the same time, it is possible for the viewer to improve convenience further. 
     Fifth Embodiment 
     Hereinafter, a fifth embodiment of the present invention will be described. Constituent elements, effects and the like according to the present embodiment are the same as those of the first to fourth embodiments unless otherwise specified. For this reason, in the following description, differences between the present embodiment and the first to fourth embodiments are mainly described, and description of the matters common to the embodiments is omitted as much as possible in order to avoid redundant description. Further, the case where a broadcast receiving apparatus according to the present embodiment is a television receiver that deals with both an MMT method and an MPEG2-TS method as a media transport method will be described below. 
     [Hardware Configuration of Broadcast Receiving Apparatus] 
     A hardware configuration of a broadcast receiving apparatus  800  is the same as that in the second embodiment. Thus, its explanation will be omitted. 
     [Classification of Asset] 
     In the media transport method corresponding to the asset, there are two methods of the MMT method and the MPEG2-TS method, and they are classified by location_type (a location type) of MMT_general_location_info ( FIG.  31   ).  FIG.  33    shows classifications of the location type. 
     [Synchronous Control of MPEG2-TS Packet] 
     &lt;First Operation Example&gt; 
     A synchronous control of an MMT packet is executed by a timestamp based on time information of an NTP (Network Time Protocol) shown in  FIG.  3   . As a hardware configuration, a clock inside the receiving apparatus, which is synchronized with an NTP shown in  FIG.  7 C . 
     On the other hand, in the MPEG2-TS method, a synchronous control is executed by a timestamp based on time information called a PCR (Program Clock Reference).  FIG.  55    shows a protocol stack of the MPEG2-TS method. This time standard based on the PCR is made up of a counter of upper 33 bits, which operates with 90 kHz, and a counter of lower 9 bits, which operates with 27 MHz 300 counts of the lower 9 bits correspond to one count of the upper 90 kHz. This counter of the upper 33 bits makes a round for about 26.5 hours, and the counter returns to 0 ( FIG.  57   ). On the other hand, the clock synchronized with the NTP is made up of upper 32 bits (in seconds) and lower 32 bits (potion after the decimal point). Therefore, the clock based on the NPT has an expressible period of about 136 years, and it is completely different from the PCR system as a system of time expression ( FIG.  57   ). 
     Therefore, the receiving apparatus that executes a process for a MPEG2-TS packet is required to have an internal clock synchronized with the PCR in addition to the clock synchronized with the NTP, and execute presentation of an asset by executing presentation of the asset in accordance with the clock or using the clock of the NTP on the basis of a relation of time between the PCR and the NTP. Further, in the case of taking precise presentation synchronization between the asset of the MMT method and the asset of the MPEG2-TS method, it is desirable that the relation of time between the PCR and the NTP is known even though the internal clock synchronized with the PCR is provided. 
     As a method of obtaining the relation of time between the PCR and the NTP, the following method may be executed, for example. First, as a method of giving a correspondence relation of time between the PCR and the NTP at the transmission side, there is a method in which the relation is described for each MMT package table. Namely, it is described in the MPT shown in  FIG.  17    as MPT_descriptor.  FIG.  56    shows an example of the descriptor. Here, a timestamp_offset parameter gives a difference between a timestamp by the PCR and a timestamp by the NTP (a timestamp offset). Here, a time based on the NPT corresponding to a time when the counter of the timestamp of the PCR used in a group of assets indicated by the MPT is return to 0 is shown in an NTP timestamp format of 64 bits. 
     Explanation is made using  FIG.  57   . In a case where a point “A” in  FIG.  57    is a PCR timestamp, a point “B” is a timestamp offset. By using a value of this timestamp offset to add a value of a PCR timestamp offset to the timestamp offset, a value of the timestamp of an NTP system is obtained. In a case where the value of the timestamp of the NTP system can be obtained, it is possible to execute a presentation process by using the clock of the NTP system even though it is the asset of the MPEG2-TS method. This makes it possible to precisely take the presentation synchronization with the asset of the MMT method. 
     Further, the timestamp offset may be described for each asset corresponding to the MPEG2-TS method. In this case, it is described in the MPT shown in  FIG.  17    as asset_descriptor. 
     In a case where one that exceeds 0 is included in the timestamp of the PCR that is used in the asset, a plurality of times in each of which a counter value as the timestamp of the PCR corresponds to 0 may exist. However, in such a case, the timestamp offset may be described at the earliest time. When explanation is made using  FIG.  57   , it is the case where there is also a timestamp of the PCR used in the asset at “A′” in addition to “A”. In this case, a value of “B” is used as the timestamp offset that is to be described in the descriptor. In the presentation process for the asset of the MPEG2-TS method, a value of the timestamp offset described in the descriptor is used at first. In a case where the value of the PCR timestamp when viewed in chronological order of the packets is reduced while causing the presentation process to proceed, it is determined that the counter makes a round. The process is continued as a value of a new time offset obtained by adding one round time of the PCR counter, that is, a value obtained by dividing 2 33  by 90 kHz (26.5 hours as an approximate value) to the value of the time offset used in the process. After that, in a case where the value PCR time offset is reduced during the process, the value of the timestamp offset may be updated in the similar manner. 
     &lt;Second Operation Example&gt; 
     Next, a process of the case where timestamp offset is not described at a transmission side will be described. In a case where timestamp offset is not described in transmission data, a value of an NTP clock in the receiving apparatus may be read when to receive the PCR timestamp, and a time of the NTP clock corresponding to a time when the counter of the timestamp of the PCR is returned to  0  may be set as the value of the timestamp offset in the similar manner to that described above. The presentation process of the asset of the MPEG2-TS method after the value of the timestamp offset is set may be executed in the similar manner to that in a case where the value of the timestamp offset is described in the descriptor described above. 
     In a case where a program is viewed at the time of broadcasting it, the value of the timestamp offset can be obtained at the receiving apparatus side as described above even though it is not described in the descriptor of the transmission data, for example. However, in a case where a program is reproduced and viewed after recording it, it is difficult to obtain the relation between the value of the NTP timestamp and the value of the PCR timestamp. Therefore, it is desirable that, in a case where a program in which an asset of the MMT method and an asset of the MPEG2-TS method are mixed is recorded, a descriptor of a timestamp offset is also recorded at the same time. In a case where the timestamp offset is not described in the transmission data at the transmission side, it is desirable that the receiving apparatus obtains the value of the timestamp offset, and records it by adding it to the received data. These recorded data may be recorded or stored in a storage unit  810  in  FIG.  24   , for example. When to view the program, these recorded data may be used and reproduced from the storage unit  810 . 
     As described above, by using the timestamp offset, which gives the relation between the NTP timestamp and the PCR timestamp to execute the presentation process for the assets, the process of presentation synchronization can be executed more precisely in the program in which the asset of the MMT method and the asset of the MPEG2-TS method are mixed. 
     &lt;Third Operation Example&gt; 
     A presentation region of the asset of the MMT method, which is to be transmitted by the media transport method, is specified by an MPU presentation region specifying descriptor ( FIG.  34   ). However, in addition to the MPEG2-TS method, a presentation region of the asset, which is to be transmitted by another media transport method, may also be specified by the MPU presentation region specifying descriptor ( FIG.  34   ). At that time, meaningless specification depending upon a type of the asset, such as mpu_sequence_number, is ignored. This makes it possible to present the asset without using a special specifying method, and it is possible to improve convenience. 
     In a case where specification of mpu_sequence_number is ignored, a presentation region of the whole asset specified by an MP table (the MPT)  30001  ( FIG.  17   ,  FIG.  28   ) follows region specification of the MPU presentation region specifying descriptor ( FIG.  34   ). 
     &lt;Fourth Operation Example&gt; 
     A presentation time of the asset transmitted by the media transport method of the MMT method is specified by an MPU timestamp descriptor ( FIG.  58   ). However, in addition to the MPEG2-TS method, a presentation time of the asset transmitted by another media transport method may also be specified by the MPU timestamp descriptor ( FIG.  58   ). At that time, meaningless specification depending upon a type of the asset, such as mpu_sequence_number, is ignored at the receiving apparatus side. In this case, a specified time is a presentation time at the head of the asset. By using this time information, it is possible to obtain a difference between the timestamp of the NTP system and the timestamp of the PCR system, and this makes it possible to take presentation synchronization between the asset transmitted by the MMT method and the asset transmitted by the MPEG2-TS method. This makes it possible to present the asset without using a special specifying method, and it is possible to improve convenience. 
     &lt;Fifth Operation Example&gt; 
     In the third operation example and the fourth operation example, the method of using the MPU presentation region specifying descriptor ( FIG.  34   ) or the MPU timestamp descriptor ( FIG.  58   ) for presentation of the asset to be transmitted by a method other than the MMT method has been described. However, a dedicated descriptor may be used. As an example of the dedicated descriptor, an asset presentation region specifying descriptor ( FIG.  59   ) and an asset timestamp descriptor ( FIG.  60   ) may be used. In these descriptors, meaningless information in other method than the MMT method, such as mpu_sequence_number, is not described. This makes it possible to improve reliability without confusing the process. 
     The descriptor for transmitting the timestamp offset or the descriptor for transmitting the presentation time of the asset other than the media transport method of the MMT method, which have been explained in the first, the third, the fourth and the fifth operation examples described above is transmitted as a descriptor in the MMT package table. In this case, it is transmitted as data that are received by a tuner/demodulating unit  831  shown in  FIG.  24    and decoded by an MMT decode processing unit  841 . 
     However, as modification example of the present operation example, it may be transmitted as data that are received by a tuner/demodulating unit  832  and decoded by a MPEG2-TS decode processing unit  842 . 
     A video of the asset transmitted by the MMT method and a video of the asset transmitted by the MPEG2-TS method, which are synchronized by the process of synchronizing that has been explained in the fifth embodiment described above, may be generated as a synthesized video by a video synthesizing unit  861  shown in  FIG.  24   , and outputted so as to be presented in any of the regions obtained by dividing the screen on the basis of the LCT, which has been explained in the first to fourth embodiments, for example. 
     As described above, the examples of the embodiments according to the present invention have been explained using the first to fifth embodiments. However, the configurations for achieving the technique of the present invention are not limited to those embodiments, and may be modified in various ways. For example, some constituent elements of an embodiment may be replaced with those of another embodiment, and a constituent element of an embodiment may be added to a constituent element of another embodiment. These modifications are all within the scope of the present invention. In addition, numerical values, messages, and others in the specification and drawings are described by way of example, and the effects of the present invention are not impaired even when values, messages, and others different from those are used. 
     A part or all of the functions and the like of the present invention described above may be achieved by means of hardware, for example, by designing such functions with integrated circuits. Alternatively, it may be achieved by means of software by causing a microprocessor unit or the like to interpret and execute operating programs for achieving respective functions. It is also possible to use hardware and software in combination. 
     Note that the software that controls the broadcast receiving apparatus  100  may be stored in advance in the ROM  103  and/or the storage (accumulation) unit  110  of the broadcast receiving apparatus  100  at the time of product shipment. The software may be acquired from the other application server  500  or the like on the Internet  200  through the LAN communication unit  121  after the product shipment. Alternatively, the software stored in a memory card, optical disc, or the like may be acquired through the extension interface unit  124 . 
     Further, control lines and data lines considered to be necessary for the description are shown in the drawings, and all the control lines and data lines included in the product are not always shown in the drawings. Actually, it is presumable that almost all constituent elements are connected with each other. 
     REFERENCE SINGS LIST 
     
         
           100 ,  800  broadcast receiving apparatus 
           100   a  antenna 
           101 ,  801  main control unit 
           102 ,  802  system bus 
           103 ,  803  ROM 
           104 ,  804  RAM 
           110 ,  810  storage unit 
           121 ,  821  LAN communication unit 
           124 ,  824  extension interface unit 
           125 ,  825  digital interface unit 
           131 ,  831 ,  832  tuner/demodulating unit 
           132  separating unit 
           141  video decoder 
           142  video color gamut conversion unit 
           143  audio decoder 
           144  caption decoder 
           145  subtitle decoder 
           146  subtitle synthesizing unit 
           147  subtitle color gamut conversion unit 
           151  data decoder 
           152  cache unit 
           153  application control unit 
           154  browser unit 
           155  application color gamut conversion unit 
           156  sound source unit 
           161 ,  861  video synthesizing unit 
           162 ,  862  monitor unit 
           163 ,  863  video output unit 
           164 ,  864  audio synthesizing unit 
           165 ,  865  speaker unit 
           166 ,  866  audio output unit 
           170 ,  870  operation input unit 
           841  MMT decode processing unit 
           842  MPEG2-TS decode processing unit 
           200  Internet 
           200   r  router device 
           200   a  access point 
           300   t  radio tower 
           300   s  broadcast satellite (or communication satellite) 
           300  broadcast station server 
           400  service provider server 
           500  other application server 
           600  mobile phone communication server 
           600   b  base station 
           700  portable information terminal