Abstract:
The MPEG-4 Multiview Video Coding (MVC) standard provides the coding tools to compress images from more than one view. Traditionally, the base view of the multiple view images has to be coded by the MPEG-4 Advance Video Coding (AVC) standard. However, in some deployments, for compatibility to legacy players, MPEG-2 Video standard has to be used for the coding of the based view. This invention provides methods and apparatuses to compute the parameters required by the MVC encoder and decoder without signalling such information in the base view that is coded by the MPEG-2 video standard.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    This invention can be used in any multimedia data coding and, more particularly, in Multiview Video Coding. 
         [0003]    2. Description of Related Art 
         [0004]    MPEG-4 Multiview Video Coding (MVC) standard is created as an extension of ISO/IEC 14496-10 Advanced Video Coding (AVC) standard. The profiles created in the MVC standard are designed to be backward compatible to some of the profiles defined in AVC standard. In another words, the decoders or players conforming to the new MVC profiles will be able to decode some of the AVC profile bitstreams. Vice versa, legacy decoders of the AVC profiles (in particularly the High profile) should also decode at least one of the views in bitstreams conforming to the new MVC profiles. 
         [0005]    In MPEG-4 Multiview Video Coding (MPEG-4 MVC) standard, as a coded base view is required to be compatible to the profiles defined by AVC standard, a legacy decoder conforming to the High Profile of the AVC standard should be able to decode a base view in the MVC bitstream conforming to the MVC profiles. The coded views are contained in Network Abstraction Layer (NAL) units and different types of NAL unit are differentiated by NAL unit type values. The non-base views are contained in NAL unit with unit type values that are reserved values in the previous versions of the AVC specification and thus these NAL units should be ignored by legacy High profile decoders. 
         [0006]    In the MPEG-4 MVC standard, a particular NAL unit called Prefix NAL unit is required to be sent together before each NAL unit containing the coded base view. This Prefix NAL unit has a NAL unit type value equal to fourteen and it is a reserved value in the previous versions of the AVC specification. 
         [0007]    The Prefix NAL unit contains additional parameters that are located in the MVC extension of the NAL unit header. These parameters are associated with the base view and are used in the encoding and decoding processes of the compressed non base views.  FIG. 1  shows a diagram on the location of NAL unit header mvc extension syntaxes. The parameters in the NAL unit header mvc extension include a non_idr_flag parameter, a prority_id parameter, a view_id parameter, a temporal_id parameter, a anchor_pic_flag parameter, a inter_view_flag parameter and a reserved_one_bit parameter. The reserved_one_bit has a value of one and it is not used for the encoding and decoding processes of the compressed non base views. 
         [0008]    In the MPEG-2 system standard (ISO/IEC 13818-1), the presentation time and decoding time of a B picture that is coded by MPEG-2 video standard is forced to be the same. In the case of the presence of a non base view picture that is coded by the MPEG-4 MVC standard, the presentation and decoding time of that non base view picture is also set to be the same as the base view B picture so that synchronization of the views can be achieved. 
       Problems to be Solved 
       [0009]    By the definition of the MVC standard, the base view has to be coded using the AVC standard. However, in some deployment, for compatibility to legacy players, the base view needs to be coded using an older standard like MPEG-2 Video standard. 
         [0010]    Typically, the motion prediction process of the non base view requires the decoded images of the base view. However the additional parameters introduced by the MVC extension of the NAL unit header cannot be carried in the coded video compressed using the MPEG-2 video standard. These parameters are required for the decoding of the coded images of the non-base view that is compressed by the MVC standard. 
         [0011]    The decoding and presentation times of the base view B picture that is coded using the MPEG-2 video is restricted to be the same as the decoding and presentation times of the non base view picture that is coded using the MPEG-4 MVC standard. But because the decoding of the non base view picture may use the decoded image of the base view B picture for inter picture prediction; the actual decoding time of the non-base view picture cannot be the same as the decoding time of the base view picture. And thus the actual presentation time of the non base view picture will be later than the presentation time of the base view picture which will create some synchronization problems for the base and non base views 
       BRIEF SUMMARY OF THE INVENTION 
     1. Means of Solving the Problems 
       [0012]    To solve the above problems, new methods are introduced to compute the parameters contained in the MVC extension of the NAL unit header for the base view image that is coded using the MPEG-2 Video standard. New methods are introduced to compute the new decoding and presentation times of the base and non base views images when the base view image is coded using the MPEG-2 video standard. 
         [0013]    What is novel about this invention is that this invention allows the values associated to the base view of the MPEG-2 coded stream that is required for the decoding of the non base view to be determined signalling new data units that may create problems in the decoding process by some legacy MPEG-2 decoders. This invention enables the decoding of a base view of a MPEG-2 video stream by legacy MPEG-2 video decoders in the market and also enables the decoding of all the coded views of the MVC stream by MVC decoders of current invention. This invention also solves the synchronization problems of the decoded base view image and the decoded non base view image by computing new decoding and presentation times from the base and non base views images. 
       2. Effects of Invention 
       [0014]    The effect of the current invention is in the form of backward compatibility of a coded MVC and MPEG-2 video stream on legacy players. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a diagram showing location of NAL unit header mvc extension parameters and picture_coding_type parameter. 
           [0016]      FIG. 2  is a flowchart showing an encoding process for the first embodiment of current invention. 
           [0017]      FIG. 3  is a flowchart showing a decoding process for the first embodiment of current invention. 
           [0018]      FIG. 4  is a flowchart showing a process to compute NAL unit header mvc extension parameters in the first embodiment of current invention. 
           [0019]      FIG. 5  is a flowchart showing a process to assign the values for a plurality of parameters from NAL unit header mvc extension parameters of a coded image of a non base view to parameters of an image of a base view. 
           [0020]      FIG. 6  is a diagram showing an example apparatus of an encoder in the first embodiment of current invention. 
           [0021]      FIG. 7  is a diagram showing an example apparatus of a decoder in the first embodiment of current invention. 
           [0022]      FIG. 8  is a diagram illustrating the location of presentation time stamp and decoding time stamp in second embodiment of current invention. 
           [0023]      FIG. 9  is a diagram illustrating the decode and display timings of a pair of stereo images and audio data in the second embodiment of current invention. 
           [0024]      FIG. 10  is a flowchart showing a decoding process for an image of a base view in the second embodiment of current invention. 
           [0025]      FIG. 11  is a flowchart showing a decoding process for an image of a non base view in the second embodiment of current invention. 
           [0026]      FIG. 12  is a flowchart showing a decoding process for audio data in the second embodiment of current invention. 
           [0027]      FIG. 13  is a diagram showing an example apparatus of a decoder in the second embodiment of current invention. 
           [0028]      FIG. 100  illustrates an overall configuration of a content providing system ex  100  for implementing content distribution services. 
           [0029]      FIG. 101  illustrates a video coding apparatus and a video decoding apparatus implemented in a digital broadcasting system ex 200 . 
           [0030]      FIG. 102  illustrates a television (receiver) ex 300  that uses the video coding method and the video decoding method described in each of the embodiments. 
           [0031]      FIG. 103  illustrates shows an example of a configuration of an information reproducing/recording unit ex 400  when data is read or written from or on an optical disk. 
           [0032]      FIG. 104  illustrates the recording medium ex 215  that is the optical disk. 
           [0033]      FIG. 105  ( a ) illustrates a cellular phone ex 114  that uses the video coding method and the video decoding method described in the embodiments. 
           [0034]      FIG. 105  ( b ) shows an example of a configuration of the cellular phone ex 114 . 
           [0035]      FIG. 106  illustrates a structure of multiplexed data that can be obtained by multiplexing at least one of a video stream, an audio stream, a presentation graphics stream (PG), and an interactive graphics stream. 
           [0036]      FIG. 107  schematically illustrates how data is multiplexed. 
           [0037]      FIG. 108  illustrates how a video stream is stored in a stream of PES packets. 
           [0038]      FIG. 109  illustrates a format of TS packets to be finally written on the multiplexed data. 
           [0039]      FIG. 110  illustrates the data structure of the PMT in detail. 
           [0040]      FIG. 111  shows that each of the multiplexed data information files is management information of the multiplexed data, and that the multiplexed data includes a system rate, a reproduction start time, and a reproduction end time. 
           [0041]      FIG. 112  shows a piece of attribute information registered in the stream attribute information, for each PID of each stream included in the multiplexed data. 
           [0042]      FIG. 113  illustrates steps of the video decoding method according to embodiment 9. 
           [0043]      FIG. 114  shows a CPU ex 502  and a driving frequency control unit ex 512  of the driving frequency switching unit ex 803 . 
           [0044]      FIG. 115  illustrates a configuration ex 800  in embodiment 11. 
           [0045]      FIG. 116  illustrates steps for executing a method in Embodiment 11. 
           [0046]      FIG. 117  shows a look-up table in which the standards of the video data are associated with the driving frequencies. 
           [0047]      FIG. 118(   a ) show an example Ex 900  of a configuration in which the decoding processing unit for implementing the video decoding method described in each of embodiments and the decoding processing unit that conforms to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1 are partly shared. 
           [0048]      FIG. 118(   b ) shows another example ex 1000  in which processing is partly shared. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0049]      FIG. 2  shows an encoding process for the first embodiment of current invention. In module  100 , an image of first view is encoded using MPEG-2 video coding tools. The first view is also known as the base view in the current invention. Next in module  102 , the coded image is written in a byte stream format conforming to the MPEG-2 video specification. In module  104 , the Network Abstraction Layer (NAL) unit header mvc extension parameters are determined for an image of the second view. The second view is also known as the non base view in the current invention. These parameters include a non_idr_flag parameter, a rority_id parameter, a view_id parameter, a temporal_id parameter, a anchor_pic_flag parameter and a inter_view_flag parameter. 
         [0050]    As shown in  FIG. 2 , in module  106 , the NAL unit header mvc extension parameters for the first view are computed. These parameters include a non_idr_flag parameter, a prority_id parameter, a view_id parameter, a temporal_id parameter, a anchor_pic_flag parameter and a inter_view_flag parameter. In module  108 , an image of second view is encoded using the NAL unit header mvc extension parameters of both first and second views and MPEG-4 MVC coding tools. Finally in module  110 , the coded image of the second view is written in NAL units conforming to the MPEG-4 MVC specification. 
         [0051]      FIG. 3  shows a decoding process for the first embodiment of current invention. Firstly in module  200 , a coded image of a first view is parsed based on MPEG-2 Video specification. The first view is also known as the base view in current invention. Next in module  202 , the image is decoded using MPEG-2 video decoding tools. And in module  204 , the NAL unit header mvc extension parameters for a coded image of a second view is parsed based on MPEG-4 MVC specification. The second view is also known as the non base view in current invention. Next in module  206 , the NAL unit header mvc extension parameters for the coded image of the first view is computed and in module  208 , the coded image of second view is parsed based on the MPEG-4 MVC specification. Finally, in module  210 , the coded image of the second view is decoded using the NAL unit header mvc extension parameters for both first and second view and MPEG-4 MVC decoding tools. 
         [0052]      FIG. 4  shows a process to compute NAL unit header mvc extension parameters in the first embodiment of current invention. These parameters include a non_idr_flag parameter, a prority_id parameter, a view_id parameter, a temporal_id parameter, a anchor_pic_flag parameter and a inter_view_flag parameter. 
         [0053]    Firstly in module  300 , the values for a plurality of parameters from NAL unit header mvc extension parameters of a coded image of a non base view (second view) is assigned to the parameters for a coded image of a base view (first view). Next in module  302 , the priority_id value for the coded image of base view is assigned with a first pre-defined value. The pre-defined value for priority_id is zero. The view_id is also assigned with a second pre-defined value in module  304 . The pre-defined value for view_id is zero. Next in module  306 , a picture_coding_type parameter is parsed from a picture header of the coded image of base view. The picture_coding_type parameter identifies if the coded picture is a I picture, P picture or B picture. And in module  308 , the picture_coding_type parameter is judged whether it contains a third pre-defined value. The third pre-defined value is the value three which represents a B picture. And if the picture_coding_type parameter contains the third pre-defined value, a inter_view_flag parameter for the coded image of base view is set to a value of zero in module  310 . Otherwise, if the picture_coding_type parameter does not contain the third pre-defined value, the inter_view_flag parameter for the coded image of base view is set to a value of one in module  312 . 
         [0054]      FIG. 5  shows a process to assign the values for a plurality of parameters from NAL unit header mvc extension parameters of a coded image of a non base view (second view) to the parameters for a coded image of a base view (first view). In module  400 , the non_idr_flag parameter for an image of a base view is assigned with the value of the non_idr_flag parameter for an image of a non base view. Similarly, in module  402 , the temporal_id parameter for the image of a base view is assigned with the value of the temporal_id parameter for the image of a non base view. And finally, in module  404 , the anchor_pic_flag parameter for the image of a base view is assigned with the value of the anchor_pic_flag parameter for the image of a non base view. 
         [0055]      FIG. 6  shows a block diagram on an example encoder apparatus in the first embodiment of the current invention. It includes a base view encoding unit using MPEG-2 coding tools  500 , a base view writing unit  502 , a base view decoding unit using MPEG-2 decoding tools  504 , a base view NAL unit header mvc extension parameters computation unit  506 , a non base view NAL unit header mvc extension parameters determination unit  508 , a memory unit  510 , a non base view encoding unit using MPEG-4 MVC coding tools  512  and a non base view writing unit  514 . 
         [0056]    Firstly, an image of base view D 501  is inputted to the base view encoding unit  500  and a compressed image D 503  is outputted to both base view writing unit  502  and base view decoding unit  504 . The pcture_coding_type parameter D 525  is also outputted form the base view encoding unit  500  to the base view NAL unit header mvc extension parameters computation unit  506 . 
         [0057]    The base view decoding unit  504  reads the compressed image of base view D 003 , decode the image using MPEG-2 video decoding tools and outputs the decoded image of base view D 005  to the memory unit  510 . 
         [0058]    As shown in  FIG. 6 , an image of non base view D 511  is inputted to both non base view NAL unit mvc extension parameters determination unit  508  and the non base view encoding unit  512 . The non base view NAL unit mvc extension parameters determination unit  508  then outputs the NAL unit header mvc extension parameters of the non base view D 513  to both base view NAL unit header mvc extension parameters computation unit  506  and the non base view encoding unit  512 . The base view Nal unit header mvc extension parameters computation unit  506  takes the pre-defined values, the picture_coding_type parameter D 525  and the NAL unit header mvc extension parameters of the non base view D 513 , assign values to the NAL unit header mvc extension parameters of base view and outputs the NAL unit header mvc extension parameters of base view D 517  to the non base view encoding unit  512 . 
         [0059]    The non base view encoding unit  512  then takes an image of non base view D 511 , the NAL unit header mvc extension parameters of the non base view D 513 , the NAL unit header mvc extension parameters of the base view D 517  and a decoded image of base view D 519 , encodes the image using MPEG-4 MVC coding tools and outputs a compressed image of non base view D 521 . 
         [0060]    Finally, the base view writing unit  502  and the non base view writing unit  514 , takes the compressed image of base view D 503  and the compressed image of non base view D 521 , respectively and outputs the compressed images D 507  and D 523 . 
         [0061]      FIG. 7  shows a block diagram on an example decoder apparatus in the first embodiment of the current invention. It includes a picture header parsing unit  600 , a base view decoding unit using MPEG-2 decoding tools  602 , a memory unit  604 , a non base view NAL unit header mvc extension parameters parser unit  608 , a base view Nal unit header mvc extension parameters computation unit  606  and a non base view decoding unit using MPEG-4 MVC decoding tools  610 . 
         [0062]    As shown in  FIG. 7 , the picture header parsing unit  600  reads a coded image of base view and outputs a compressed image to the base view decoding unit  602 . The base view decoding unit takes the compressed base view image D 603 , decodes using MPEG-2 decoding tools and outputs a decoded image of base view D 613 . The outputted decoded image of base view D 613  is then stored in the memory unit  604 . 
         [0063]    The picture header parsing unit  600  also outputs a picture_coding_type parameter to the base view NAL unit header mvc extension parameters computation unit  606 . 
         [0064]    The non base view NAL unit header mvc extension parameters parser unit  608 , takes the compressed image of non base view D 609  and outputs the NAL unit header mvc extension parameters of non base view D 611  to both base view NAL unit header mvc extension parameters computation unit  606  and non base view decoding unit  610 . The non base view NAL unit header mvc extension parameters parser unit  608  also outputs the compressed image of non base view D 615  to the non base view decoding unit  610 . Then the base view NAL unit header mvc extension parameters computation unit  606  takes the pre-defined values D 607 , the picture_coding_type parameter D 605  and the NAL unit header mvc extension parameters of non base view D 611 , assigns values to the NAL unit header mvc extension parameters of base view and outputs the NAL unit header mvc extension parameters of base view D 621  to the non base view decoding unit  610 . 
         [0065]    Finally the non base view decoding unit  610  takes the decoded image of base view D 617 , NAL unit header mvc extension parameters of base view D 621 , parsed NAL unit header mvc extension parameters of non base view D 611  and a compressed image of non base view D 615 , decodes using MPEG-4 MVC decoding tools and outputs the decoded image of non base view D 019 . 
         [0066]      FIG. 8  shows a diagram illustrating the location of the presentation time stamp (PTS) and decoding time stamp (DTS) in the second embodiment of the current invention. As shown in the diagram, the PTS can be found in the PES header that encapsulates the media data containing either an image of base view, an image of non base view or audio samples. As shown in the diagram, in the case when PES data contains an image of the base view that is a B picture and in the case the PES data contains audio samples, the DTS is the same as the PTS and the DTS may not be present in the PES header of a PES packet. 
         [0067]      FIG. 9  shows a diagram illustrating the decoding and display timings of a pair of stereo images and the associated audio samples in the second embodiment of the current invention. As shown in the diagram, the presentation time for the image of the base view and the decoding and presentation times of the image of the non base view and associated audio samples are all delayed by one frame interval to ensure that the decoded media as synchronized in playback. The frame interval is computed as the time duration equal to the inverse of the frame rate. 
         [0068]      FIG. 10  shows a decoding process for an image of a base view in the second embodiment of the current invention. Firstly in module  1000 , a presentation time is parsed from a header of an image of base view. Specifically, the parameter is parsed from a PES packet header containing a part of the image. Next in module  1002 , a decoding time is derived for the coded image of the base view. If the coded image is a B picture, the decoded time is derived to be the same value as the presentation time. And in module  1004 , the image is decoded at the derived decoding time and a new presentation time for the decoded image is computed by delaying the parsed presentation time by an offset value in module  1006 . The offset value is the time duration that is the inverse of the frame rate. And finally in module  1008 , the decoded image of the base view is presented at the new computed presentation time. 
         [0069]      FIG. 11  shows a decoding process for an image of a non base view in the second embodiment of the current invention. Firstly in module  1100 , a presentation time is parsed from a header of an image of non base view. Specifically, the parameter is parsed from a PES packet header containing a part of the image. Next in module  1102 , a decoding time is parsed from the header. And in module  1104 , a new decoding time for the image of the non base view is computed by delaying the decoding time by an offset value. The offset value is the time duration that is the inverse of the frame rate. And in module  1106 , the image is decoded at the newly computed decoding time and a new presentation time for the decoded image is computed by delaying the parsed presentation time by the same offset value in module  1108 . And finally in module  1110 , the decoded image of the non base view is presented at the new computed presentation time. 
         [0070]      FIG. 12  shows a decoding process for audio samples in the second embodiment of the current invention. Firstly in module  1200 , a presentation time is parsed from a header of the audio samples. Specifically, the parameter is parsed from a PES packet header containing a part of audio samples. Next in module  1202 , a decoding time is parsed from the header. And in module  1204 , a new decoding time for audio samples is computed by delaying the decoding time by an offset value. The offset value is the time duration that is the inverse of the video frame rate. And in module  1206 , the audio samples are decoded at the newly computed decoding time and a new presentation time for the decoded audio samples is computed by delaying the parsed presentation time by the same offset value in module  1208 . And finally in module  1210 , the decoded audio samples are presented at the new computed presentation time. 
         [0071]      FIG. 13  shows an example apparatus of a decoder in the second embodiment of the current invention. It consists of a PES header parsing unit  1300 , an image decoding unit  1302 , a memory unit  1304 , a display unit  1306  and a DTS and PTS computation unit  1308 . 
         [0072]    Firstly the PES header parsing unit  1300  reads a coded image which is encapsulated in PES packets D 1301  and outputs the presentation time stamp (PTS) and if present, the decoding time stamp (DTS) D 1303  to the DTS and PTS computation unit  1308 . The PES header parsing unit  1300  also outputs the coded image D 1305  to the image decoding unit  1302 . The DTS and PTS computation unit reads the parsed presentation time stamp (PTS) and the decoding time stamp (DTS) D 1303  and outputs new computed decoding time D 1311  to the image decoding unit  1302  and new computed presentation time D 1313  to the display unit  1306 . The image decoding unit  1302  reads the decoding time D 1311  and the coded image D 1305  and outputs the decoded image D 1307  to the memory unit  1304 . The display unit D 1315  then reads the presentation time D 1313  and the decoded image D 1309  from the memory unit  1304  and outputs the image for display D 1315 . 
       Embodiment A 
       [0073]    The processing described in each of the Embodiments shown in  FIGS. 100 to 118(   b ) can be simply implemented in an independent computer system, by recording, in a recording medium, a program for implementing the configurations of the video coding method and the video decoding method described in each of Embodiments. The recording media may be any recording media as long as the program can be recorded, such as a magnetic disk, an optical disk, a magnetic optical disk, an IC card, and a semiconductor memory. 
         [0074]    Hereinafter, the applications to the video coding method and the video decoding method described in each of Embodiments and systems using thereof will be described. 
         [0075]      FIG. 100  illustrates an overall configuration of a content providing system ex 100  for implementing content distribution services. The area for providing communication services is divided into cells of desired size, and base stations ex 106 , ex 107 , ex 108 , ex 109 , and ex 110  which are fixed wireless stations are placed in each of the cells. 
         [0076]    The content providing system ex 100  is connected to devices, such as a computer ex 111 , a personal digital assistant (PDA) ex 112 , a camera ex 113 , a cellular phone ex 114  and a game machine ex 115 , via the Internet ex 101 , an Internet service provider ex 102 , a telephone network ex  104 , as well as the base stations ex  106  to ex  110 , respectively. 
         [0077]    However, the configuration of the content providing system ex 100  is not limited to the configuration shown in  FIG. 100 , and a combination in which any of the elements are connected is acceptable. In addition, each device may be directly connected to the telephone network ex 104 , rather than via the base stations ex 106  to ex 110  which are the fixed wireless stations. Furthermore, the devices may be interconnected to each other via a short distance wireless communication and others. 
         [0078]    The camera exi  13 , such as a digital video camera, is capable of capturing video. A camera exi  16 , such as a digital video camera, is capable of capturing both still images and video. Furthermore, the cellular phone ex 114  may be the one that meets any of the standards such as Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Wideband-Code Division Multiple Access (W-CDMA), Long Term Evolution (LTE), and High Speed Packet Access (HSPA). Alternatively, the cellular phone ex 114  may be a Personal Handyphone System (PHS). 
         [0079]    In the content providing system ex 100 , a streaming server ex 103  is connected to the camera ex 113  and others via the telephone network ex 104  and the base station ex 109 , which enables distribution of images of a live show and others. In such a distribution, a content (for example, video of a music live show) captured by the user using the camera ex 113  is coded as described above in each of Embodiments, and the coded content is transmitted to the streaming server ex 103 . On the other hand, the streaming server ex 103  carries out stream distribution of the transmitted content data to the clients upon their requests. The clients include the computer ex  111 , the PDA ex  112 , the camera ex  113 , the cellular phone ex  114 , and the game machine ex 115  that are capable of decoding the above-mentioned coded data. Each of the devices that have received the distributed data decodes and reproduces the coded data. 
         [0080]    The captured data may be coded by the camera ex 113  or the streaming server ex 103  that transmits the data, or the coding processes may be shared between the camera ex  113  and the streaming server ex 103 . Similarly, the distributed data may be decoded by the clients or the streaming server ex 103 , or the decoding processes may be shared between the clients and the streaming server ex  103 . Furthermore, the data of the still images and video captured by not only the camera ex 113  but also the camera ex 116  may be transmitted to the streaming server ex 103  through the computer ex 111 . The coding processes may be performed by the camera ex 116 , the computer ex 111 , or the streaming server ex 103 , or shared among them. 
         [0081]    Furthermore, the coding and decoding processes may be performed by an LSI ex 500  generally included in each of the computer ex 111  and the devices. The LSI ex 500  may be configured of a single chip or a plurality of chips. Software for coding and decoding video may be integrated into some type of a recording medium (such as a CD-ROM, a flexible disk, and a hard disk) that is readable by the computer ex 111  and others, and the coding and decoding processes may be performed using the software. Furthermore, when the cellular phone ex 114  is equipped with a camera, the image data obtained by the camera may be transmitted. The video data is data coded by the LSI ex 500  included in the cellular phone ex 114 . 
         [0082]    Furthermore, the streaming server ex 103  may be composed of servers and computers, and may decentralize data and process the decentralized data, record, or distribute data. 
         [0083]    As described above, the clients may receive and reproduce the coded data in the content providing system ex 100 . In other words, the clients can receive and decode information transmitted by the user, and reproduce the decoded data in real time in the content providing system ex 100 , so that the user who does not have any particular right and equipment can implement personal broadcasting. 
         [0084]    Aside from the example of the content providing system ex  100 , at least one of the video coding apparatus and the video decoding apparatus described in each of Embodiments may be implemented in a digital broadcasting system ex 200  illustrated in  FIG. 101 . More specifically, a broadcast station ex 201  communicates or transmits, via radio waves to a broadcast satellite ex 202 , multiplexed data obtained by multiplexing audio data and others onto video data. The video data is data coded by the video coding method described in each of Embodiments. Upon receipt of the multiplexed data, the broadcast satellite ex 202  transmits radio waves for broadcasting. Then, a home-use antenna ex 204  with a satellite broadcast reception function receives the radio waves. 
         [0085]    Next, a device such as a television (receiver) ex 300  and a set top box (STB) ex 217  decodes the received multiplexed data, and reproduces the decoded data. 
         [0086]    Furthermore, a reader/recorder ex 218  (i) reads and decodes the multiplexed data recorded on a recording media ex 215 , such as a DVD and a BD, or (i) codes video signals in the recording medium ex 215 , and in some cases, writes data obtained by multiplexing an audio signal on the coded data. The reader/recorder ex 218  can include the video decoding apparatus or the video coding apparatus as shown in each of Embodiments. In this case, the reproduced video signals are displayed on the monitor ex 219 , and can be reproduced by another device or system using the recording medium ex 215  on which the multiplexed data is recorded. It is also possible to implement the video decoding apparatus in the set top box ex 217  connected to the cable ex 203  for a cable television or to the antenna ex 204  for satellite and/or terrestrial broadcasting, so as to display the video signals on the monitor ex 219  of the television ex 300 . The video decoding apparatus may be implemented not in the set top box but in the television ex 300 . 
         [0087]      FIG. 102  illustrates the television (receiver) ex 300  that uses the video coding method and the video decoding method described in each of Embodiments. The television ex 300  includes: a tuner ex 301  that obtains or provides multiplexed data obtained by multiplexing audio data onto video data, through the antenna ex 204  or the cable ex 203 , etc. that receives a broadcast; a modulation/demodulation unit ex 302  that demodulates the received multiplexed data or modulates data into multiplexed data to be supplied outside; and a multiplexing/demultiplexing unit ex 303  that demultiplexes the modulated multiplexed data into video data and audio data, or multiplexes video data and audio data coded by a signal processing unit ex 306  into data. 
         [0088]    The television ex 300  further includes: a signal processing unit ex 306  including an audio signal processing unit ex 304  and a video signal processing unit ex 305  that decode audio data and video data and code audio data and video data, respectively; and an output unit ex 309  including a speaker ex 307  that provides the decoded audio signal, and a display unit ex 308  that displays the decoded video signal, such as a display. Furthermore, the television ex 300  includes an interface unit ex 317  including an operation input unit ex 312  that receives an input of a user operation. Furthermore, the television ex 300  includes a control unit ex 310  that controls overall each constituent element of the television ex 300 , and a power supply circuit unit ex 311  that supplies power to each of the elements. Other than the operation input unit ex 312 , the interface unit ex 317  may include: a bridge ex 313  that is connected to an external device, such as the reader/recorder ex 218 ; a slot unit ex 314  for enabling attachment of the recording medium ex 216 , such as an SD card; a driver ex 315  to be connected to an external recording medium, such as a hard disk; and a modem ex 316  to be connected to a telephone network. Here, the recording medium ex 216  can electrically record information using a non-volatile/volatile semiconductor memory element for storage. The constituent elements of the television ex 300  are connected to each other through a synchronous bus. 
         [0089]    First, the configuration in which the television ex 300  decodes multiplexed data obtained from outside through the antenna ex 204  and others and reproduces the decoded data will be described. In the television ex 300 , upon a user operation through a remote controller ex 220  and others, the multiplexing/demultiplexing unit ex 303  demultiplexes the multiplexed data demodulated by the modulation/demodulation unit ex 302 , under control of the control unit ex 310  including a CPU. Furthermore, the audio signal processing unit ex 304  decodes the demultiplexed audio data, and the video signal processing unit ex 305  decodes the demultiplexed video data, using the decoding method described in each of Embodiments, in the television ex 300 . The output unit ex 309  provides the decoded video signal and audio signal outside, respectively. When the output unit ex 309  provides the video signal and the audio signal, the signals may be temporarily stored in buffers ex 318  and ex 319 , and others so that the signals are reproduced in synchronization with each other. Furthermore, the television ex 300  may read multiplexed data not through a broadcast and others but from the recording media ex 215  and ex 216 , such as a magnetic disk, an optical disk, and a SD card. Next, a configuration in which the television ex 300  codes an audio signal and a video signal, and transmits the data outside or writes the data on a recording medium will be described. In the television ex 300 , upon a user operation through the remote controller ex 220  and others, the audio signal processing unit ex 304  codes an audio signal, and the video signal processing unit ex 305  codes a video signal, under control of the control unit ex 310  using the coding method described in each of Embodiments. The multiplexing/demultiplexing unit ex 303  multiplexes the coded video signal and audio signal, and provides the resulting signal outside. When the multiplexing/demultiplexing unit ex 303  multiplexes the video signal and the audio signal, the signals may be temporarily stored in the buffers ex 320  and ex 321 , and others so that the signals are reproduced in synchronization with each other. Here, the buffers ex 318 , ex 319 , ex 320 , and ex 321  may be plural as illustrated, or at least one buffer may be shared in the television ex 300 . Furthermore, data may be stored in a buffer so that the system overflow and underflow may be avoided between the modulation/demodulation unit ex 302  and the multiplexing/demultiplexing unit ex 303 , for example. 
         [0090]    Furthermore, the television ex 300  may include a configuration for receiving an AV input from a microphone or a camera other than the configuration for obtaining audio and video data from a broadcast or a recording medium, and may code the obtained data. Although the television ex 300  can code, multiplex, and provide outside data in the description, it may be capable of only receiving, decoding, and providing outside data but not the coding, multiplexing, and providing outside data. 
         [0091]    Furthermore, when the reader/recorder ex 218  reads or writes multiplexed data from or on a recording medium, one of the television ex 300  and the reader/recorder ex 218  may decode or code the multiplexed data, and the television ex 300  and the reader/recorder ex 218  may share the decoding or coding. 
         [0092]    As an example,  FIG. 103  illustrates a configuration of an information reproducing/recording unit ex 400  when data is read or written from or on an optical disk. The information reproducing/recording unit ex 400  includes constituent elements ex 401 , ex 402 , ex 403 , ex 404 , ex 405 , ex 406 , and ex 407  to be described hereinafter. The optical head ex 401  irradiates a laser spot in a recording surface of the recording medium ex 215  that is an optical disk to write information, and detects reflected light from the recording surface of the recording medium ex 215  to read the information. The modulation recording unit ex 402  electrically drives a semiconductor laser included in the optical head ex 401 , and modulates the laser light according to recorded data. The reproduction demodulating unit ex 403  amplifies a reproduction signal obtained by electrically detecting the reflected light from the recording surface using a photo detector included in the optical head ex 401 , and demodulates the reproduction signal by separating a signal component recorded on the recording medium ex 215  to reproduce the necessary information. The buffer ex 404  temporarily holds the information to be recorded on the recording medium ex 215  and the information reproduced from the recording medium ex 215 . The disk motor ex 405  rotates the recording medium ex 215 . The servo control unit ex 406  moves the optical head ex 401  to a predetermined information track while controlling the rotation drive of the disk motor ex 405  so as to follow the laser spot. The system control unit ex 407  controls overall the information reproducing/recording unit ex 400 . The reading and writing processes can be implemented by the system control unit ex 407  using various information stored in the buffer ex 404  and generating and adding new information as necessary, and by the modulation recording unit ex 402 , the reproduction demodulating unit ex 403 , and the servo control unit ex 406  that record and reproduce information through the optical head ex 401  while being operated in a coordinated manner. The system control unit ex 407  includes, for example, a microprocessor, and executes processing by causing a computer to execute a program for read and write. 
         [0093]    Although the optical head ex 401  irradiates a laser spot in the description, it may perform high-density recording using near field light. 
         [0094]      FIG. 104  illustrates the recording medium ex 215  that is the optical disk. On the recording surface of the recording medium ex 215 , guide grooves are spirally formed, and an information track ex 230  records, in advance, address information indicating an absolute position on the disk according to change in a shape of the guide grooves. The address information includes information for determining positions of recording blocks ex 231  that are a unit for recording data. Reproducing the information track ex 230  and reading the address information in an apparatus that records and reproduces data can lead to determination of the positions of the recording blocks. Furthermore, the recording medium ex 215  includes a data recording area ex 233 , an inner circumference area ex 232 , and an outer circumference area ex 234 . The data recording area ex 233  is an area for use in recording the user data. The inner circumference area ex 232  and the outer circumference area ex 234  that are inside and outside of the data recording area ex 233 , respectively are for specific use except for recording the user data. The information reproducing/recording unit  400  reads and writes coded audio, coded video data, or multiplexed data obtained by multiplexing the coded audio and video data, from and on the data recording area ex 233  of the recording medium ex 215 . 
         [0095]    Although an optical disk having a layer, such as a DVD and a BD is described as an example in the description, the optical disk is not limited to such, and may be an optical disk having a multilayer structure and capable of being recorded on a part other than the surface. Furthermore, the optical disk may have a structure for multidimensional recording/reproduction, such as recording of information using light of colors with different wavelengths in the same portion of the optical disk and for recording information having different layers from various angles. 
         [0096]    Furthermore, a car ex 210  having an antenna ex 205  can receive data from the satellite ex 202  and others, and reproduce video on a display device such as a car navigation system ex 211  set in the car ex 210 , in the digital broadcasting system ex 200 . Here, a configuration of the car navigation system ex 211  will be a configuration, for example, including a GPS receiving unit from the configuration illustrated in  FIG. 102 . The same will be true for the configuration of the computer ex  111 , the cellular phone ex  114 , and others. 
         [0097]      FIG. 105  ( a ) illustrates the cellular phone ex 114  that uses the video coding method and the video decoding method described in Embodiments. The cellular phone ex 114  includes: an antenna ex 350  for transmitting and receiving radio waves through the base station ex 110 ; a camera unit ex 365  capable of capturing moving and still images; and a display unit ex 358  such as a liquid crystal display for displaying the data such as decoded video captured by the camera unit ex 365  or received by the antenna ex 350 . The cellular phone ex 114  further includes: a main body unit including an operation key unit ex 366 ; an audio output unit ex 357  such as a speaker for output of audio; an audio input unit ex 356  such as a microphone for input of audio; a memory unit ex 367  for storing captured video or still pictures, recorded audio, coded or decoded data of the received video, the still pictures, e-mails, or others; and a slot unit ex 364  that is an interface unit for a recording medium that stores data in the same manner as the memory unit ex 367 . 
         [0098]    Next, an example of a configuration of the cellular phone ex 114  will be described with reference to  FIG. 105  ( b ). In the cellular phone ex 114 , a main control unit ex 360  designed to control overall each unit of the main body including the display unit ex 358  as well as the operation key unit ex 366  is connected mutually, via a synchronous bus ex 370 , to a power supply circuit unit ex 361 , an operation input control unit ex 362 , a video signal processing unit ex 355 , a camera interface unit ex 363 , a liquid crystal display (LCD) control unit ex 359 , a modulation/demodulation unit ex 352 , a multiplexing/demultiplexing unit ex 353 , an audio signal processing unit ex 354 , the slot unit ex 364 , and the memory unit ex 367 . 
         [0099]    When a call-end key or a power key is turned ON by a user&#39;s operation, the power supply circuit unit ex 361  supplies the respective units with power from a battery pack so as to activate the cell phone ex 114 . 
         [0100]    In the cellular phone ex 114 , the audio signal processing unit ex 354  converts the audio signals collected by the audio input unit ex 356  in voice conversation mode into digital audio signals under the control of the main control unit ex 360  including a CPU, ROM, and RAM. Then, the modulation/demodulation unit ex 352  performs spread spectrum processing on the digital audio signals, and the transmitting and receiving unit ex 351  performs digital-to-analog conversion and frequency conversion on the data, so as to transmit the resulting data via the antenna ex 350 . 
         [0101]    Also, in the cellular phone ex 114 , the transmitting and receiving unit ex 351  amplifies the data received by the antenna ex 350  in voice conversation mode and performs frequency conversion and the analog-to-digital conversion on the data. Then, the modulation/demodulation unit ex 352  performs inverse spread spectrum processing on the data, and the audio signal processing unit ex 354  converts it into analog audio signals, so as to output them via the audio output unit ex 356 . 
         [0102]    Furthermore, when an e-mail in data communication mode is transmitted, text data of the e-mail inputted by operating the operation key unit ex 366  and others of the main body is sent out to the main control unit ex 360  via the operation input control unit ex 362 . The main control unit ex 360  causes the modulation/demodulation unit ex 352  to perform spread spectrum processing on the text data, and the transmitting and receiving unit ex 351  performs the digital-to-analog conversion and the frequency conversion on the resulting data to transmit the data to the base station ex 110  via the antenna ex 350 . When an e-mail is received, processing that is approximately inverse to the processing for transmitting an e-mail is performed on the received data, and the resulting data is provided to the display unit ex 358 . 
         [0103]    When video, still images, or video and audio in data communication mode is or are transmitted, the video signal processing unit ex 355  compresses and codes video signals supplied from the camera unit ex 365  using the video coding method shown in each of Embodiments, and transmits the coded video data to the multiplexing/demultiplexing unit ex 353 . In contrast, during when the camera unit ex 365  captures video, still images, and others, the audio signal processing unit ex 354  codes audio signals collected by the audio input unit ex 356 , and transmits the coded audio data to the multiplexing/demultiplexing unit ex 353 . 
         [0104]    The multiplexing/demultiplexing unit ex 353  multiplexes the coded video data supplied from the video signal processing unit ex 355  and the coded audio data supplied from the audio signal processing unit ex 354 , using a predetermined method. 
         [0105]    Then, the modulation/demodulation unit ex 352  performs spread spectrum processing on the multiplexed data, and the transmitting and receiving unit ex 351  performs digital-to-analog conversion and frequency conversion on the data so as to transmit the resulting data via the antenna ex 350 . 
         [0106]    When receiving data of a video file which is linked to a Web page and others in data communication mode or when receiving an e-mail with video and/or audio attached, in order to decode the multiplexed data received via the antenna ex 350 , the multiplexing/demultiplexing unit ex 353  demultiplexes the multiplexed data into a video data bit stream and an audio data bit stream, and supplies the video signal processing unit ex 355  with the coded video data and the audio signal processing unit ex 354  with the coded audio data, through the synchronous bus ex 370 . The video signal processing unit ex 355  decodes the video signal using a video decoding method corresponding to the coding method shown in each of Embodiments, and then the display unit ex 358  displays, for instance, the video and still images included in the video file linked to the Web page via the LCD control unit ex 359 . Furthermore, the audio signal processing unit ex 354  decodes the audio signal, and the audio output unit ex 357  provides the audio. 
         [0107]    Furthermore, similarly to the television ex 300 , a terminal such as the cellular phone ex 114  probably have 3 types of implementation configurations including not only (i) a transmitting and receiving terminal including both a coding apparatus and a decoding apparatus, but also (ii) a transmitting terminal including only a coding apparatus and (iii) a receiving terminal including only a decoding apparatus. Although the digital broadcasting system ex 200  receives and transmits the multiplexed data obtained by multiplexing audio data onto video data in the description, the multiplexed data may be data obtained by multiplexing not audio data but character data related to video onto video data, and may be not multiplexed data but video data itself. 
         [0108]    As such, the video coding method and the video decoding method in each of Embodiments can be used in any of the devices and systems described. Thus, the advantages described in each of Embodiments can be obtained. 
         [0109]    Furthermore, the present invention is not limited to Embodiments, and various modifications and revisions are possible without departing from the scope of the present invention. 
       Embodiment B 
       [0110]    Video data can be generated by switching, as necessary, between (i) the video coding method or the video coding apparatus shown in each of Embodiments and (ii) a video coding method or a video coding apparatus in conformity with a different standard, such as MPEG-2, MPEG4-AVC, and VC-1. 
         [0111]    Here, when a plurality of video data that conforms to the different standards is generated and is then decoded, the decoding methods need to be selected to conform to the different standards. However, since to which standard each of the plurality of the video data to be decoded conform cannot be detected, there is a problem that an appropriate decoding method cannot be selected. 
         [0112]    In order to solve the problem, multiplexed data obtained by multiplexing audio data and others onto video data has a structure including identification information indicating to which standard the video data conforms. The specific structure of the multiplexed data including the video data generated in the video coding method and by the video coding apparatus shown in each of Embodiments will be hereinafter described. The multiplexed data is a digital stream in the MPEG2-Transport Stream format. 
         [0113]      FIG. 106  illustrates a structure of the multiplexed data. As illustrated in  FIG. 106 , the multiplexed data can be obtained by multiplexing at least one of a video stream, an audio stream, a presentation graphics stream (PG), and an interactive graphics stream. The video stream represents primary video and secondary video of a movie, the audio stream (IG) represents a primary audio part and a secondary audio part to be mixed with the primary audio part, and the presentation graphics stream represents subtitles of the movie. Here, the primary video is normal video to be displayed on a screen, and the secondary video is video to be displayed on a smaller window in the primary video. Furthermore, the interactive graphics stream represents an interactive screen to be generated by arranging the GUI components on a screen. The video stream is coded in the video coding method or by the video coding apparatus shown in each of Embodiments, or in a video coding method or by a video coding apparatus in conformity with a conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1. The audio stream is coded in accordance with a standard, such as Dolby-AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, and linear PCM. 
         [0114]    Each stream included in the multiplexed data is identified by PID. For example, 0×1011 is allocated to the video stream to be used for video of a movie, 0×1100 to 0×111F are allocated to the audio streams, 0×1200 to 0×121F are allocated to the presentation graphics streams, 0×1400 to 0×141F are allocated to the interactive graphics streams, 0×1B00 to 0×1B1F are allocated to the video streams to be used for secondary video of the movie, and 0×A00 to 0×1A1F are allocated to the audio streams to be used for the secondary video to be mixed with the primary audio. 
         [0115]      FIG. 107  schematically illustrates how data is multiplexed. First, a video stream ex 235  composed of video frames and an audio stream ex 238  composed of audio frames are transformed into a stream of PES packets ex 236  and a stream of PES packets ex 239 , and further into TS packets ex 237  and TS packets ex 240 , respectively. Similarly, data of a presentation graphics stream ex 241  and data of an interactive graphics stream ex 244  are transformed into a stream of PES packets ex 242  and a stream of PES packets ex 245 , and further into TS packets ex 243  and TS packets ex 246 , respectively. These TS packets are multiplexed into a stream to obtain multiplexed data ex 247 . 
         [0116]      FIG. 108  illustrates how a video stream is stored in a stream of PES packets in more detail. The first bar in  FIG. 108  shows a video frame stream in a video stream. The second bar shows the stream of PES packets. As indicated by arrows denoted as yy 1 , yy 2 , yy 3 , and yy 4  in  FIG. 108 , the video stream is divided into pictures as I pictures, B pictures, and P pictures each of which is a video presentation unit, and the pictures are stored in a payload of each of the PES packets. Each of the PES packets has a PES header, and the PES header stores a Presentation Time-Stamp (PTS) indicating a display time of the picture, and a Decoding Time-Stamp (DTS) indicating a decoding time of the picture. 
         [0117]      FIG. 109  illustrates a format of TS packets to be finally written on the multiplexed data. Each of the TS packets is a 188-byte fixed length packet including a 4-byte TS header having information, such as a PID for identifying a stream and a 184-byte TS payload for storing data. The PES packets are divided, and stored in the TS payloads, respectively. When a BD ROM is used, each of the TS packets is given a 4-byte TP_Extra_Header, thus resulting in 192-byte source packets. The source packets are written on the multiplexed data. The TP_Extra_Header stores information such as an Arrival_Time_Stamp (ATS). The ATS shows a transfer start time at which each of the TS packets is to be transferred to a PID filter. The source packets are arranged in the multiplexed data as shown at the bottom of  FIG. 109 . The numbers incrementing from the head of the multiplexed data are called source packet numbers (SPNs). 
         [0118]    Each of the TS packets included in the multiplexed data includes not only streams of audio, video, subtitles and others, but also a Program Association Table (PAT), a Program Map Table (PMT), and a Program Clock Reference (PCR). The PAT shows what a PID in a PMT used in the multiplexed data indicates, and a PID of the PAT itself is registered as zero. The PMT stores PIDs of the streams of video, audio, subtitles and others included in the multiplexed data, and attribute information of the streams corresponding to the PIDs. The PMT also has various descriptors relating to the multiplexed data. The descriptors have information such as copy control information showing whether copying of the multiplexed data is permitted or not. The PCR stores STC time information corresponding to an ATS showing when the PCR packet is transferred to a decoder, in order to achieve synchronization between an Arrival Time Clock (ATC) that is a time axis of ATSs, and an System Time Clock (STC) that is a time axis of PTSs and DTSs. 
         [0119]      FIG. 110  illustrates the data structure of the PMT in detail. A PMT header is disposed at the top of the PMT. The PMT header describes the length of data included in the PMT and others. A plurality of descriptors relating to the multiplexed data is disposed after the PMT header. Information such as the copy control information is described in the descriptors. After the descriptors, a plurality of pieces of stream information relating to the streams included in the multiplexed data is disposed. Each piece of stream information includes stream descriptors each describing information, such as a stream type for identifying a compression codec of a stream, a stream PID, and stream attribute information (such as a frame rate or an aspect ratio). The stream descriptors are equal in number to the number of streams in the multiplexed data. 
         [0120]    When the multiplexed data is recorded on a recording medium and others, it is recorded together with multiplexed data information files. 
         [0121]    Each of the multiplexed data information files is management information of the multiplexed data as shown in  FIG. 111 . The multiplexed data information files are in one to one correspondence with the multiplexed data, and each of the files includes multiplexed data information, stream attribute information, and an entry map. 
         [0122]    As illustrated in  FIG. 111 , the multiplexed data includes a system rate, a reproduction start time, and a reproduction end time. The system rate indicates the maximum transfer rate at which a system target decoder to be described later transfers the multiplexed data to a PID filter. The intervals of the ATSs included in the multiplexed data are set to not higher than a system rate. The reproduction start time indicates a PTS in a video frame at the head of the multiplexed data. An interval of one frame is added to a PTS in a video frame at the end of the multiplexed data, and the PTS is set to the reproduction end time. 
         [0123]    As shown in  FIG. 112 , a piece of attribute information is registered in the stream attribute information, for each PID of each stream included in the multiplexed data. Each piece of attribute information has different information depending on whether the corresponding stream is a video stream, an audio stream, a presentation graphics stream, or an interactive graphics stream. Each piece of video stream attribute information carries information including what kind of compression codec is used for compressing the video stream, and the resolution, aspect ratio and frame rate of the pieces of picture data that is included in the video stream. Each piece of audio stream attribute information carries information including what kind of compression codec is used for compressing the audio stream, how many channels are included in the audio stream, which language the audio stream supports, and how high the sampling frequency is. The video stream attribute information and the audio stream attribute information are used for initialization of a decoder before the player plays back the information. 
         [0124]    In Embodiment 9, the multiplexed data to be used is of a stream type included in the PMT. Furthermore, when the multiplexed data is recorded on a recording medium, the video stream attribute information included in the multiplexed data information is used. More specifically, the video coding method or the video coding apparatus described in each of Embodiments includes a step or a unit for allocating unique information indicating video data generated by the video coding method or the video coding apparatus in each of Embodiments, to the stream type included in the PMT or the video stream attribute information. With the configuration, the video data generated by the video coding method or the video coding apparatus described in each of Embodiments can be distinguished from video data that conforms to another standard. 
         [0125]    Furthermore,  FIG. 113  illustrates steps of the video decoding method according to Embodiment 9. In Step exS 100 , the stream type included in the PMT or the video stream attribute information is obtained from the multiplexed data. Next, in Step exS 101 , it is determined whether or not the stream type or the video stream attribute information indicates that the multiplexed data is generated by the video coding method or the video coding apparatus in each of Embodiments. When it is determined that the stream type or the video stream attribute information indicates that the multiplexed data is generated by the video coding method or the video coding apparatus in each of Embodiments, in Step exS 102 , decoding is performed by the video decoding method in each of Embodiments. Furthermore, when the stream type or the video stream attribute information indicates conformance to the conventional standards, such as MPEG-2, MPEG4-AVC, and VC-1, in Step exS 103 , decoding is performed by a video decoding method in conformity with the conventional standards. 
         [0126]    As such, allocating a new unique value to the stream type or the video stream attribute information enables determination whether or not the video decoding method or the video decoding apparatus that is described in each of Embodiments can perform decoding. Even when multiplexed data that conforms to a different standard, an appropriate decoding method or apparatus can be selected. Thus, it becomes possible to decode information without any error. Furthermore, the video coding method or apparatus, or the video decoding method or apparatus in Embodiment 9 can be used in the devices and systems described above. 
       Embodiment C 
       [0127]    Each of the video coding method, the video coding apparatus, the video decoding method, and the video decoding apparatus in each of Embodiments is typically achieved in the form of an integrated circuit or a Large Scale Integrated (LSI) circuit. As an example of the LSI,  FIG. 114  illustrates a configuration of the LSI ex 500  that is made into one chip. The LSI ex 500  includes elements ex 501 , ex 502 , ex 503 , ex 504 , ex 505 , ex 506 , ex 507 , ex 508 , and ex 509  to be described below, and the elements are connected to each other through a bus ex 510 . The power supply circuit unit ex 505  is activated by supplying each of the elements with power when the power supply circuit unit ex 505  is turned on. 
         [0128]    For example, when coding is performed, the LSI ex 500  receives an AV signal from a microphone ex 117 , a camera ex 113 , and others through an AV IO ex 509  under control of a control unit ex 501  including a CPU ex 502 , a memory controller ex 503 , a stream controller ex 504 , and a driving frequency control unit ex 512 . The received AV signal is temporarily stored in an external memory ex 511 , such as an SDRAM. Under control of the control unit ex 501 , the stored data is segmented into data portions according to the processing amount and speed to be transmitted to a signal processing unit ex 507 . Then, the signal processing unit ex 507  codes an audio signal and/or a video signal. Here, the coding of the video signal is the coding described in each of Embodiments. Furthermore, the signal processing unit ex 507  sometimes multiplexes the coded audio data and the coded video data, and a stream IO ex 506  provides the multiplexed data outside. The provided multiplexed data is transmitted to the base station ex 107 , or written on the recording media ex 215 . When data sets are multiplexed, the data should be temporarily stored in the buffer ex 508  so that the data sets are synchronized with each other. 
         [0129]    Although the memory ex 511  is an element outside the LSI ex 500 , it may be included in the LSI ex 500 . The buffer ex 508  is not limited to one buffer, but may be composed of buffers. Furthermore, the LSI ex 500  may be made into one chip or a plurality of chips. 
         [0130]    Furthermore, although the control unit ex 510  includes the CPU ex 502 , the memory controller ex 503 , the stream controller ex 504 , the driving frequency control unit ex 512 , the configuration of the control unit ex 510  is not limited to such. For example, the signal processing unit ex 507  may further include a CPU. Inclusion of another CPU in the signal processing unit ex 507  can improve the processing speed. Furthermore, as another example, the CPU ex 502  may serve as or be a part of the signal processing unit ex 507 , and, for example, may include an audio signal processing unit. In such a case, the control unit ex 501  includes the signal processing unit ex 507  or the CPU ex 502  including a part of the signal processing unit ex 507 . 
         [0131]    The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. 
         [0132]    Moreover, ways to achieve integration are not limited to the LSI, and a special circuit or a general purpose processor and so forth can also achieve the integration. Field Programmable Gate Array (FPGA) that can be programmed after manufacturing LSIs or a reconfigurable processor that allows re-configuration of the connection or configuration of an LSI can be used for the same purpose. 
         [0133]    In the future, with advancement in semiconductor technology, a brand-new technology may replace LSI. The functional blocks can be integrated using such a technology. The possibility is that the present invention is applied to biotechnology. 
       Embodiment D 
       [0134]    When video data generated in the video coding method or by the video coding apparatus described in each of Embodiments is decoded, compared to when video data that conforms to a conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1 is decoded, the processing amount probably increases. Thus, the LSI ex 500  needs to be set to a driving frequency higher than that of the CPU ex 502  to be used when video data in conformity with the conventional standard is decoded. However, when the driving frequency is set higher, there is a problem that the power consumption increases. 
         [0135]    In order to solve the problem, the video decoding apparatus, such as the television ex 300  and the LSI ex 500  is configured to determine to which standard the video data conforms, and switch between the driving, frequencies according to the determined standard.  FIG. 115  illustrates a configuration ex 800  in Embodiment 11. A driving frequency switching unit ex 803  sets a driving frequency to a higher driving frequency when video data is generated by the video coding method or the video coding apparatus described in each of Embodiments. Then, the driving frequency switching unit ex 803  instructs a decoding processing unit ex 801  that executes the video decoding method described in each of Embodiments to decode the video data. When the video data conforms to the conventional standard, the driving frequency switching unit ex 803  sets a driving frequency to a lower driving frequency than that of the video data generated by the video coding method or the video coding apparatus described in each of Embodiments. Then, the driving frequency switching unit ex 803  instructs the decoding processing unit ex 802  that conforms to the conventional standard to decode the video data. 
         [0136]    More specifically, the driving frequency switching unit ex 803  includes the CPU ex 502  and the driving frequency control unit ex 512  in  FIG. 114 . Here, each of the decoding processing unit ex 801  that executes the video decoding method described in each of Embodiments and the decoding processing unit ex 802  that conforms to the conventional standard corresponds to the signal processing unit ex 507  in  FIG. 114 . The CPU ex 502  determines to which standard the video data conforms. Then, the driving frequency control unit ex 512  determines a driving frequency based on a signal from the CPU ex 502 . Furthermore, the signal processing unit ex 507  decodes the video data based on the signal from the CPU ex 502 . For example, the identification information described in Embodiment 9 is probably used for identifying the video data. The identification information is not limited to the one described in Embodiment 9 but may be any information as long as the information indicates to which standard the video data conforms. For example, when which standard video data conforms to can be determined based on an external signal for determining that the video data is used for a television or a disk, etc., the determination may be made based on such an external signal. Furthermore, the CPU ex 502  selects a driving frequency based on, for example, a look-up table in which the standards of the video data are associated with the driving frequencies as shown in  FIG. 117 . The driving frequency can be selected by storing the look-up table in the buffer ex 508  and in an internal memory of an LSI, and with reference to the look-up table by the CPU ex 502 . 
         [0137]      FIG. 116  illustrates steps for executing a method in Embodiment 11. First, in Step exS 200 , the signal processing unit ex 507  obtains identification information from the multiplexed data. Next, in Step exS 201 , the CPU ex 502  determines whether or not the video data is generated by the coding method and the coding apparatus described in each of Embodiments, based on the identification information. When the video data is generated by the video coding method and the video coding apparatus described in each of Embodiments, in Step exS 202 , the CPU ex 502  transmits a signal for setting the driving frequency to a higher driving frequency to the driving frequency control unit ex 512 . Then, the driving frequency control unit ex 512  sets the driving frequency to the higher driving frequency. On the other hand, when the identification information indicates that the video data conforms to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1, in Step exS 203 , the CPU ex 502  transmits a signal for setting the driving frequency to a lower driving frequency to the driving frequency control unit ex 512 . Then, the driving frequency control unit ex 512  sets the driving frequency to the lower driving frequency than that in the case where the video data is generated by the video coding method and the video coding apparatus described in each of Embodiment. 
         [0138]    Furthermore, along with the switching of the driving frequencies, the power conservation effect can be improved by changing the voltage to be applied to the LSI ex 500  or an apparatus including the LSI ex 500 . For example, when the driving frequency is set lower, the voltage to be applied to the LSI ex 500  or the apparatus including the LSI ex 500  is probably set to a voltage lower than that in the case where the driving frequency is set higher. 
         [0139]    Furthermore, when the processing amount for decoding is larger, the driving frequency may be set higher, and when the processing amount for decoding is smaller, the driving frequency may be set lower as the method for setting the driving frequency. Thus, the setting method is not limited to the ones described above. For example, when the processing amount for decoding video data in conformity with MPEG4-AVC is larger than the processing amount for decoding video data generated by the video coding method and the video coding apparatus described in each of Embodiments, the driving frequency is probably set in reverse order to the setting described above. 
         [0140]    Furthermore, the method for setting the driving frequency is not limited to the method for setting the driving frequency lower. For example, when the identification information indicates that the video data is generated by the video coding method and the video coding apparatus described in each of Embodiments, the voltage to be applied to the LSI ex 500  or the apparatus including the LSI ex 500  is probably set higher. When the identification information indicates that the video data conforms to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1, the voltage to be applied to the LSI ex 500  or the apparatus including the LSI ex 500  is probably set lower. As another example, when the identification information indicates that the video data is generated by the video coding method and the video coding apparatus described in each of Embodiments, the driving of the CPU ex 502  does not probably have to be suspended. When the identification information indicates that the video data conforms to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1, the driving of the CPU ex 502  is probably suspended at a given time because the CPU ex 502  has extra processing capacity. Even when the identification information indicates that the video data is generated by the video coding method and the video coding apparatus described in each of Embodiments, in the case where the CPU ex 502  has extra processing capacity, the driving of the CPU ex 502  is probably suspended at a given time. In such a case, the suspending time is probably set shorter than that in the case where when the identification information indicates that the video data conforms to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1. 
         [0141]    Accordingly, the power conservation effect can be improved by switching between the driving frequencies in accordance with the standard to which the video data conforms. Furthermore, when the LSI ex 500  or the apparatus including the LSI ex 500  is driven using a battery, the battery life can be extended with the power conservation effect. 
       Embodiment E 
       [0142]    There are cases where a plurality of video data that conforms to different standards, is provided to the devices and systems, such as a television and a mobile phone. In order to enable decoding the plurality of video data that conforms to the different standards, the signal processing unit ex 507  of the LSI ex 500  needs to conform to the different standards. However, the problems of increase in the scale of the circuit of the LSI ex 500  and increase in the cost arise with the individual use of the signal processing units ex 507  that conform to the respective standards. 
         [0143]    In order to solve the problem, what is conceived is a configuration in which the decoding processing unit for implementing the video decoding method described in each of Embodiments and the decoding processing unit that conforms to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1 are partly shared. Ex 900  in  FIG. 118(   a ) shows an example of the configuration. For example, the video decoding method described in each of Embodiments and the video decoding method that conforms to MPEG4-AVC have, partly in common, the details of processing, such as entropy coding, inverse quantization, deblocking filtering, and motion compensated prediction. The details of processing to be shared probably includes use of a decoding processing unit ex 902  that conforms to MPEG4-AVC. In contrast, a dedicated decoding processing unit ex 901  is probably used for other processing unique to the present invention. Since the present invention is characterized by a transformation unit in particular, for example, the dedicated decoding processing unit ex 901  is used for inverse transform. Otherwise, the decoding processing unit is probably shared for one of the entropy coding, inverse quantization, deblocking filtering, and motion compensated prediction, or all of the processing. The decoding processing unit for implementing the video decoding method described in each of Embodiments may be shared for the processing to be shared, and a dedicated decoding processing unit may be used for processing unique to that of MPEG4-AVC. 
         [0144]    Furthermore, ex 1000  in  FIG. 118(   b ) shows another example in that processing is partly shared. This example uses a configuration including a dedicated decoding processing unit ex 1001  that supports the processing unique to the present invention, a dedicated decoding processing unit ex 1002  that supports the processing unique to another conventional standard, and a decoding processing unit ex 1003  that supports processing to be shared between the video decoding method in the present invention and the conventional video decoding method. Here, the dedicated decoding processing units ex 1001  and ex 1002  are not necessarily specialized for the processing of the present invention and the processing of the conventional standard, respectively, and may be the ones capable of implementing general processing. Furthermore, the configuration of Embodiment 12 can be implemented by the LSI ex 500 . 
         [0145]    As such, reducing the scale of the circuit of an LSI and reducing the cost are possible by sharing the decoding processing unit for the processing to be shared between the video decoding method in the present invention and the video decoding method in conformity with the conventional standard.