Abstract:
A broadcast receiving device configured to receive broadcasted digital programs includes a tuner to select a channel from a plurality of channels, so that a desired digital program may be received via the selected channel; a recording component to record the received program and copy control information associated with the received program; a digital terminal to output the program recorded on the recording component to a video recording device coupled to the digital terminal; and a controller to control the output of the recorded program to the video recording device that is coupled to the digital terminal. The recorded program is not output via the digital terminal if more than one video recording device is coupled to the digital terminal and if the copy control information of the recorded program imposes restriction on copying of the recorded program.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]     The present application claims priority to Japanese Patent Application No.2003-403967, filed on Dec. 3, 2003.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to a broadcast receiving device for receiving broadcasts such as digital broadcasts, and a stream output device for recording and playback of stream data such as digital video/audio signals.  
         [0003]     With the recent development of digital video signal processing, settop boxes (STBs) for reception of satellite broadcasts, digital AV apparatuses such as digital VTR (DVTR) for recording and playback of digital broadcast programs, and disk recorders have been manufactured successively. As a digital interface which is most suitable for transmitting video/audio signals while keeping the digital signal format between these digital AV apparatuses, a high speed serial bus (hereinafter referred to as a “1394 bus”) is available as defined by IEEE 1394 standards. Stream and control commands can be simultaneously transmitted/received on the 1394 bus, and as stream transmission/reception control and control commands, IEC61883 standards and the AV/C command set are provided.  
         [0004]     As a technique for prevention of the unauthorized copying of contents, a DTCP (Digital Transmission Contents Protection) specification has been adopted in the 1394 bus. In the DTCP specification, the video/audio stream is assigned with copy control information describing conditions for copying and data copying is sorted into any of three modes of “copy free” (unlimited copying), “copy never” (copying prohibited), and “copy one generation” (single copying enabled). The recording apparatus such as digital VTR is permitted to receive and record only a stream subject for “copy free” or “copy one generation.” As for the latter, after recording a stream subject to “copy one generation”, the copy control information is changed to “no more copies” (copying disabled), thus inhibiting other recording apparatuses from recording the contents any further.  
         [0005]     On the other hand, a stream recording/playback apparatus such as a so-called hard disk drive (HDD) recorder has recently become available for recording video/audio stream data using a hard disk drive (HDD). Due to the fact that the disk capacity in the apparatus in the case of a HDD recorder is limited, if the free disk space decreases, the user must transfer the contents to be stored to a VTR or optical disk device to be stored in a storage medium such as a tape or optical disk.  
         [0006]     For this reason, in the DTCP specification, the contents once recorded in the recording medium as “no more copies” are copied to another recording medium and consequently deleted from the original recording medium or playback is disabled. This function of transferring the contents is defined as a “move function”. This move function can be executed only with a built-in or digitally connected single recording medium and it is prohibited that the contents with a length exceeding 1 minute are in a playback-enabled state at both the move source device and the move destination device during the move operation. A technology for mounting the move function was described in the following patents:  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     In the afore the DTCP specification, if the contents described as “no more copies” are moved to another digitally connected stream recording/playback apparatus, the operation must be executed only for a single recording medium. Therefore, it is important to have such a mechanism so that unauthorized copying of the contents to a device other than the move destination device can be prohibited. However, when the move function is executed, a variety of unexpected situations can occur including the case when verification with another device has already been completed prior to the initiation of the move and the case when the move destination device is remotely controlled by another device during the move operation; thus, special care must be taken when mounting.  
         [0008]     In addition, the contents at the move source will be deleted or playback will be disabled at the end of the move so that if the move fails due to insufficient space in the recording medium or a mis-operation, users can no longer playback the contents.  
         [0009]     The embodiments of the present invention provide a stream data recording/playback apparatus having a move function which can be executed more robustly for users and is configured to be mounted more easily.  
         [0010]     In one embodiment, if a device other than the move source device is connected before initiation of the move, the initiation of the move is prohibited until achieving a status wherein only the move source device is connected. If another device is connected during the execution of the move, the move operation is stopped temporarily and after confirming such a state that only the move source device is connected, the move operation is restarted. As a result, the situation that contents are received by multiple devices at the same time can be easily avoided.  
         [0011]     The contents subject to the move are temporarily stored in another memory which is not accessible externally prior to initiation of move, and if the move is successful, the contents are deleted from the memory after completing the move. If the move fails due to disconnection, the contents can be recovered by analog regeneration from the memory with some restrictions. As a result, the contents are not lost and can be played even if the move is not successful.  
         [0012]     In one embodiment, a broadcast receiving device configured to receive broadcasted digital programs includes a tuner to select a channel from a plurality of channels, so that a desired digital program may be received via the selected channel; a recording component to record the received program and copy control information associated with the received program; a digital terminal to output the program recorded on the recording component to a video recording device coupled to the digital terminal; and a controller to control the output of the recorded program to the video recording device that is coupled to the digital terminal. The recorded program is not output via the digital terminal if more than one video recording device is coupled to the digital terminal and if the copy control information of the recorded program imposes restriction on copying of the recorded program.  
         [0013]     In another embodiment, a video device includes a recording component to record a video program received from an external source, the video program being recorded with copy control information; a digital terminal to output the video program recorded on the recording component to an external video recording device coupled to the digital terminal; a controller to control the output of the recorded program to the external video recording device that is coupled to the digital terminal; and a recording medium that stores a list of authorized external video recording devices to which the recorded program may be moved by the video device. The recorded program is prevented from being moved to the external video recording device that is coupled to the digital terminal if the external video recording device is not included in the list.  
         [0014]     In yet another embodiment, a method for operating a digital video streaming device includes receiving a video program from an external source, the video program being associated with copy control information; recording the video program and copy control information to a recording medium of the streaming device; and determining whether or not an external video recording device coupled to a digital terminal of the streaming device is an authorized device by accessing a list of authorized devices. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  shows a configuration example of the system as an embodiment of the present invention.  
         [0016]      FIG. 2  shows a block configuration example of the broadcast receiving device (STB) according to an embodiment of the present invention.  
         [0017]      FIG. 3  shows a block configuration example of the digital VTR (DVTR) according to an embodiment of the present invention.  
         [0018]      FIG. 4  shows a flowchart showing the initial procedures of a move process between the broadcast receiving device and the digital VTR according to an embodiment of the present invention.  
         [0019]      FIG. 5  shows a flowchart showing the execution procedures of a move process between the broadcast receiving device and the digital VTR according to an embodiment of the present invention.  
         [0020]      FIG. 6  shows a flowchart showing the interrupt procedures of a move process between the broadcast receiving device and the digital VTR accoding to an embodiment of the present invention.  
         [0021]      FIG. 7  shows a flowchart showing the end procedures of a move process between the broadcast receiving device and the digital VTR according to an embodiment of the present invention.  
         [0022]      FIG. 8  shows an example screen displayed in the case when a move process fails in the broadcast receiving device according to an embodiment of the present invention.  
         [0023]      FIG. 9  shows a configuration example of the list of the devices subject to the move process loaded in the broadcast receiving device according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Embodiments of the present invention will be described below with reference to the accompanying drawings.  
       EXAMPLE 1  
       [0025]      FIG. 1  is an example for explaining the present invention and shows an AV system containing multiple stream recording/playback apparatuses. In the AV system, a broadcast receiving device (STB)  100 , a digital VTR (DVTR)  200 , DVD recorder (DVD)  300  are digitally connected by the 1394 bus  20 . A monitor  30  is connected to STB  100  by analog connection.  
         [0026]     With STB  100 , a broadcast program, is received with control commands by the antennas  10  to be played on the monitor  30 . The broadcast program and copy commands (or copy control information) can be stored in a built-in recording memory. In addition, the digital outputs and control commands of the broadcast program can be transmitted via the 1394 bus  20  to other DVTR  200  and DVD  300 .  
         [0027]     The DVTR  200  and DVD  300  can record the broadcast program received via the 1394 bus  20  with a removable recording disk.  
         [0028]     Next, using  FIG. 2 , a configuration example of the STB in  FIG. 1  will be explained. STB  100  is comprised of a tuner processing unit  101 , a descrambler  102 , a de-multiplexer  103 , a decoder  104 , an input processing unit  105 , a timer management unit  106 , a recording/playback processing unit  107 , a digital I/F  108 , a program recording memory  109 , a control unit  110 , an analog output terminal  111 , and a digital I/O terminal  112 .  
         [0029]     The tuner processing unit  101  selects a desirable channel from multiple channels received from a broadcasting station and demodulates the program which has been digitally modulated. The descrambler  102  cancels the scrambled signal of the broadcasted programs applied so that only the channels subscribed from the service provider are receivable. The de-multiplexer  103  extracts audio data and video data from the broadcasted programs.  
         [0030]     The decoder  104  decodes the compressed audio data and video data which will be expanded to the original audio signals and video signals. These signals can be output to the outside such as the monitor  30  via the analog output terminal  111 . The input processing unit  105  is the section where a user operates the STP  101  using a remote control or touch panel. The timer management unit  106  manages the current time information and timer reservations of the broadcasted programs. The recording/playback processing unit  107  controls recording of the received broadcasted programs in the program recording memory  109  and controls playback for reproducing broadcasted programs recorded in the program recording memory  109 .  
         [0031]     The digital I/F  108  transmits AV stream and control commands with other AV apparatuses (e.g., DVTR  200  and DVD  300 ) connected by the 1394 bus  20  via the digital I/O terminal  112 , and performs coding of the transmitted AV stream or decoding of the coded AV stream. The program recording memory  109  is a memory to record broadcasted programs. It can be provided in the form of a magnetic disk, optical disk, memory card and their combined hybrid modes. The control unit  110  is a unit to control operations at various units in the STB  100 .  
         [0032]     Similarly, a configuration of the DVTA  200  will be explained using  FIG. 3 . DVTR  200  is comprised of an input processing unit  201 , a digital I/F  202 , a timer management unit  203 , a recording/playback processing unit  204 , a recording memory  205 , a control unit  206 , a digital I/O terminal  207 , and an analog input terminal  208 . The input processing unit  201  is the area where a user operates the DVTR  200  using a remote control or a touch panel.  
         [0033]     The digital I/F  202  transmits AV stream and control commands with other AV apparatuses (e.g., STV  100  and DVD  300 ) connected by the 1394 bus  20  via the digital I/O terminal  207 , and also performs coding of the transmitted AV stream and decoding of the coded AV stream.  
         [0034]     The timer management unit  203  manages the current time information and the timer reservations of the broadcasted programs. The recording/playback processing unit  204  controls a stream received via the digital I/O terminal  207  or the analog input terminal  208  in the recording memory  205 , and also controls playback for playing a stream recorded in the recording memory  205 . In the case of DVTR, this is a magnetic disk. The control unit  206  is a unit to generally control operations at various units in the EVTR  200 . DVD  300  has the same configuration as DVTR  200  except that the recording memory  205  of the DVTR  200  is an optical disk.  
         [0035]     Next, among the AV systems shown in  FIG. 1 , the procedures to transfer the broadcasted program recorded in the program recording memory  109  of the STB  100  to the recording memory  205  of the DVTR  200  via the 1394 bus  20  will be described below.  
         [0036]     Initially, the procedures required when the STB  100  starts a transfer process with DVTR  200  will be explained using  FIG. 4 . When a user instructs a transfer process via the input processing unit  105  of the STP  100 , the control unit  110  starts a transfer process program (Step  401 ). The control unit  110  extracts the contents for “no more copies” stored in the program recording memory  109  and displays the extracted information on the monitor  30  for the user to select the contents to be transferred via the input processing unit  105  (Step  402 ). Subsequently, the control unit  110  displays all the stream recording devices registered in the STB  100  on the monitor  30  for the user to select a stream recording device (DVTR  200  in this case) at the transfer destination via the input processing unit  105  while it informs the user to disconnect devices other than DVTR  200  (DVD  300  in this case) by displaying a message on the monitor  30  (Step  403 ). When the user disconnects the DVD  300  and is instructed to go forward to the next step, the control unit  110  acquires information in the AV apparatus which is currently located on the 1394 bus  20  via the digital I/F  108  (Step  404 ) and checks whether only the DVTR  200  is currently connected on the 1394 bus  20  (Step  405 ). If only DVTR  200  is present, a status acquisition command is issued on the 1394 bus  20  via the digital I/F  108  in order to acquire a current status (Step  406 ). If other devices in addition to the DVTR  200  are connected, a message is displayed on the monitor  30  again to give a warning or notification to the user to disconnect all devices other than DVTR  200  to further proceed with the transfer process (Step  407 ).  
         [0037]     If the status of the DVTR  200  acquired at Step  406  shows a currently stopped state, a connection is established between the digital I/F  108  of the STB  100  and the digital I/F  202  of the DVTR  200  in order to send a stream based on the stream copying protocol of the IEC61883 standards (Step  408 ). Based on the DTCP specification, it starts transmitting the stream as “copy one generation” (can be an empty packet) on the 1394 bus  20  via the digital I/F  108 . Once the digital I/F  202  of the DVTR  200  at the reception side receives the stream, it requests authentication for the digital I/F  108  of the STB  100  and executes mutual authentication between the STB  100  and the DVTR  200 . If the authentication is successful, the coded stream transmitted from the STB  100  can be correctly decoded by the DVTR  200  (Step  410 ). In order to change the DVTR  200  in a recording temporarily stopped state, a recording temporarily stop command is issued on the 1394 bus  20  (Step  411 ).  
         [0038]     Next, a process  500  for executing a transfer between the STB  100  and the DVTR  200  will be explained by referring to  FIG. 5 . The control unit  110  of the STB  100  checks whether the contents subject to the move in transfer as selected at Step  402  in  FIG. 4  is restricted for copying in the analog system (Step  501 ). If there is no restriction, the contents are temporarily copied to an area which can not be accessed externally on the program recording memory  109  or a separate memory (Step  502 ). In order to set the DVTR  200  in a recording start state, a recording start command is issued on the 1394 bus  20  (Step  503 ). After confirming that the DVTR  200  has started recording, the contents subject to the move for “copy one generation” are transmitted to the 1394 bus  20  via the digital I/F  108  (Step  504 ).  
         [0039]     Once the transfer execution has begun, the control unit  110  of the STB  100  periodically issues a status acquisition command for the DVTR  200  to acquire the operational status of the DVTR  200  (Step  505 ). The information of the AV apparatus currently located on the 1394 bus  20  via the digital I/F  108  is acquired (Step  506 ). In addition, it always checks whether the DVTR  200  is currently recoding and no other devices besides the DVTR  200  are currently connected on the 1394 bus  20  (Step  507 ). In addition, the contents which have already been transmitted are periodically deleted or disabled for playback (Step  508 ).  
         [0040]     If the capacity of the recording memory  205  set in the DVTR  200  runs out in the middle or if the operational status of the DVTR  200  is shifted to a status other than recording when a user mistakenly operates the DVTR  200  by a remote control, an interrupt process is executed (Step  509 ). The details of the interrupt process will be explained below by referring to  FIG. 6 .  
         [0041]     Once all the contents to be moved are transmitted (Step  510 ), the STB  100  issues a stop recording command on the 1394 bus  20  in order to stop the recording status of the DVTR  200  (Step  511 ) and executes a stop process (Step  512 ). The details of the end process will be explained below by referring to  FIG. 7 .  
         [0042]     In Step  509 , a user may accidentally operate the STB  100  using a remote control in addition to the DVTR  200  to stop transmission of the contents. Regarding the dubbing process other than the transfer process (“copy free contents”), the transmission stop of the contents can be instructed by remote operation during the dubbing. In contrast, regarding the transfer process, there is a method of avoiding instruction to stop transmission of the contents by remote controlled operation while executing the transfer process.  
         [0043]     Next, the procedures to interrupt the transfer process of the Step  508  will be explained by referring to  FIG. 6 . As mentioned above, if the operational status of the DVTR  200  as the transfer source device shifts to a status other than recording for some reason, as mentioned above, the STB  100  temporarily stops transmission of the contents to the 1394 bus  20  (Step  601 ), and a message saying that the transfer process has been interrupted is displayed on the monitor  30  to inform the user (Step  602 ). After applying necessary processes such as setting another recording memory  205  in the DVTR  200 , when the user instructs continuation of the move process via the input processing unit  105  (Step  603 ), the control unit  110  of the STB  100  issues a resume recording command in order to keep the DVTR  200  in a recording state (Step  604 ) to reopen the transmission of the contents on the 1394 bus  20  (Step  605 ). If the user does not instruct the continuation of the transfer process at Step  602  or if an instruction from the user is not input for a certain period, the process shifts to an end process  511 .  
         [0044]     When another device (e.g., DVD  300 ) is connected on the 1394 bus  20  during the move operation and the bus is reset, the same process as the interrupt process  508  is executed. Specifically if the STB  100  detects the occurrence of a bus reset, the control unit  110  acquires information of the AV apparatus currently located on the 1394 bus  20  via the digital I/F  108  to confirm that only the DVTR  200  is connected. If another device besides the DVTR  200  is detected to be connected, a stop recording temporarily command is issued in order to stop the recording status of the DVTR  200  and the interrupt process  508  is executed.  
         [0045]     Next, the procedures necessary when the STB  100  ends the transfer process with the DVTR  200  at the Step  511  will be explained by referring to  FIG. 7 .  
         [0046]     The control unit  110  of the STB  100  confirms that the contents transferred are not present in the program recording memory  109  (Step  701 ). In this case, even if a portion of the contents transferred is present, all the contents are deleted or playback is disabled (Step  702 ).  
         [0047]     Subsequently, it confirms the execution results of the transfer process (Step  703 ) and checks whether the copy of the contents is present in the area which is not accessible externally on the program recording memory  109  or in another memory at the Step  502  (Step  704 ). Finally, the execution results of the transfer process are informed on the monitor  30  to the user (Step  706 ).  
         [0048]     If the transfer process is successful at Step  703  and a copy of the contents is present at Step  704 , the copy is deleted (Step  705 ) and a message stating that the transfer process has been successful is presented at Step  706 .  
         [0049]     On the other hand, if the transfer process was unsuccessful due to an interruption, a message saying that the transfer process was unsuccessful is displayed (Step  800 ) as shown in  FIG. 8 . If a copy of the contents is present, a message stating that the contents can be reproduced from the analog output terminal  111  via the decoder  104  is displayed. In this case, sending the contents on the 1394 bus  20  via the digital I/F  108  is prohibited. In addition, regarding the contents having a restriction of analog copy, a process such as macro vision is applied to the contents sent from the analog output terminal  111  so that it can not be recorded in another stream recording device.  
         [0050]     As described above, even if the move process fails, the contents can be played back. In the case of the contents without any restrictions in the analog copy, they can be recorded in other stream recording device using analog signals. In this case, the contents can be reproduced under the conditions of down-converting of the picture quality for a certain period or at a restricted number of frequencies.  
         [0051]     If the transfer process is unsuccessful, a screen with selection options as in  801  can be shown to the users.  
         [0052]     If the move process is interrupted, those copied in the separate memory can be deleted based on the percentage of the contents transferred relative to the entire contents (e.g., if one half or more of the contents have already been transferred).  
         [0053]     Furthermore, if the STB  100  and the monitor  30  are integrated in the system, the contents copied in the separate memory can be reproduced only on the built-in monitor  30  instead of sending the contents outside via the digital I/F  108  and analog output terminal  111 .  
         [0054]     Information of the AV system which is currently located on the 1394 bus  20  which is acquired at Step  404  in  FIG. 4  and at Step  506  in  FIG. 5 , an example of the method of checking whether the device connected at Step  405  in  FIG. 4  and at Step  507  in  FIG. 5  is the only move source device, will be explained.  
         [0055]     If a device is connected on the 1394 bus  20 , addresses from 0 to 62 called note ID, are automatically allocated for this device without overlapping with other devices. This allocated node ID may vary whenever the connection configuration changes. In the asynchronous communications used for control commands, communications are performed using the node ID. On the other hand, ordinary AV apparatuses such as STB  100  and DVTR  200  which are connected to the 1394 bus  20  have identifiers, such as specific, unique ID.  
         [0056]     After acquiring the node ID present on the 1394 bus  20  in the Step  404  and Step  506  and checking that the node ID are only 0 or 1 at the Step  405  and Step  507 , the presence of recording ability at the transfer destination device can be confirmed. Alternatively, after acquiring the unique ID of the entire system present on the 1394 bus  20  in the Step  404  and Step  506  and checking that the number of unique IDs acquired at Step  405  and Step  507  is 1, the presence of recording ability at the transfer destination device can be confirmed.  
         [0057]     In addition to methods, a move process can be applied for a specific apparatus in order not to perform a transfer process for an unauthorized apparatus equipped with recording functions (e.g., a system having two recording media which can record at the same time). For example, a list  900  of devices subject to the transfer process as shown in  FIG. 9  is loaded in the control unit  110  of the STB  100 . In this list  900 , information that can unconditionally specify the AV apparatuses subject to the transfer process, such as manufacturers&#39; names and model names are registered. Subsequently, when node IDs of the AV apparatuses located on the 1394 bus  20  at Step  404  and Step  506  or unique IDs along with the information are acquired, and the fact that no other devices besides the transfer destination devices are connected at Step  405  and Step  507  is checked, it is necessary to confirm that the transfer destination devices are those registered in the list  900  subject to the transfer process in this embodiment. If a transfer destination device is the device registered in the list, a transfer process is executed, whereas if it is a non-registered device, a transfer process is interrupted. The contents of the list  900  subject to the transfer process are stored after applying the coding process in order to protect from external hackers. It is possible to upgrade the contents of the list  900  via broadcasting, Internet, IC cards, and special terminals.  
         [0058]     As mentioned above, even though the authentication process is completed with devices other than the move destination devices before execution of the move, the move process can not be executed unless these devices are disconnected. Inevitably only a move source device (STB  100 ) and a move destination device (DVTR  200 ) are present on the 1394 bus  20  during the execution of the transfer so that unauthorized duplication using other devices can be easily prevented. The move destination device can be operated exactly in the same way as when recording the contents as the ordinary “copy one generation”.  
         [0059]     The contents subject to the transfer are copied in advance in a separate memory area before the execution of the transfer, and if the transfer process fails, the contents of the copy can be reproduced in an analog format so that the programs which should have been transferred for users can be left in an analog format.  
         [0060]     In the present embodiments, STB  100  was used as a transfer source device, but DVTR  200  and DVD  300  can also be used as a such.  
         [0061]     According to the present embodiment, the contents with restricted copying which are recorded once in a stream data recording/playback apparatus can be copied to another stream data recording/playback apparatus without concerns for creating an unauthorized copy. If copying of the stream data fails due to insufficient recording area and operational errors, analog reproduction is possible. Therefore, a system which is user friendly with high security is provided.  
         [0062]     The present invention has been described in terms of specific embodiments. These specific embodiments may be modified without departing from the scope of the present invention. Accordingly, the appended claims should be used to interpret the scope of the present invention.