JP5159143B2 - Video system - Google Patents

Description

  The present invention relates to a technique for performing special playback such as fast-forward playback in a video system that distributes video data from a source device to a sink device and displays video on the sink device.

  In a video system that distributes video data from a source device to a sink device and displays video on the sink device, a technique for performing special playback such as fast-forward playback is an original consisting of an I picture, P picture, and B picture in the source device. From the video stream (MPEG video stream), only I pictures or only I pictures and P pictures are extracted, and a video stream consisting of only I pictures or only I pictures and P pictures is reconstructed. A technique is known in which fast-forward playback is realized by distributing to a sink device, and sequentially reproducing and displaying one picture in one display frame period in the sink device in the same manner as a normal video stream. (For example, Patent Document 1).

Here, the I picture is a picture obtained by intra-coding a video frame, and is a picture that does not require another video frame for decoding. In addition, a P picture is obtained by inter-frame coding (forward inter-frame coding) with a reference frame, with a video frame of one picture immediately before the playback time of an I picture and another P picture as a reference frame. It is an encoded picture. A B picture is an inter-frame coding (bi-directional inter-frame coding) between reference frames using video frames of two pictures immediately before and immediately after the playback time of an I picture and other P pictures as reference frames. This is a picture encoded by
JP 2003-309811 A

  According to the technique described in Patent Document 1, the playback speed of fast-forward playback is such that the ratio of the number of pictures of I pictures or I pictures to P pictures relative to the total number of pictures in the original video stream, that is, the original video stream There is a problem that the ratio of the number of pictures that can be transferred from the source device to the sink device with respect to the number of pictures inside is limited.

  Therefore, an object of the present invention is to perform special playback at a wider variety of playback speeds in a video system that distributes video data from a source device to a sink device and displays video on the sink device.

  In order to achieve the above object, the present invention includes a source device that distributes a video stream formed from a plurality of encoded pictures, and the distribution of the video stream received from the source device, and is included in the video stream. In a video system having one or a plurality of sink devices that decode and display each picture, when performing fast forward playback at N times speed on the source device, an average of pictures M (where M> N) One picture per picture is extracted according to the playback time order on the video stream, and the extracted pictures are sequentially added so that the transfer period of each picture is an average M / N display frame period. Special reproduction picture distribution means for transferring from the source device to the sink device, and the source device in the sink device A decoding means for sequentially decoding the pictures transferred from the image, and, in each display frame cycle, if the decoding by the decoding means for the next picture of the picture displayed in the immediately preceding display frame cycle is completed, Special playback picture display processing that displays the next picture and displays the picture displayed in the previous display frame period again when the next picture of the picture displayed in the previous display frame period has not been decoded. Means.

  According to such a video system, the ratio of the number of pictures to be transferred from the source device to the sink device with respect to the number of pictures in the video stream is M: 1, and the transfer cycle of each picture is M / N (where M> N) By setting the display frame period, 1 / M pictures of the number of pictures in the video stream are displayed such that the display period of each picture is an average M / N display frame period. Therefore, it is possible to realize N-times fast playback in a pseudo manner. Therefore, by appropriately setting the ratio of the number of pictures to be transferred and the transfer cycle of each picture, it is possible to realize fast reverse playback at various speeds, and transfer from the source device to the sink device for the number of pictures in the video stream. The playback speed is not uniquely limited by the ratio of the number of pictures that can be made. In addition, the number of pictures transferred from the source device to the sink device can be suppressed to be smaller than the number of display frame periods for performing display by fast-forward playback.

  In order to achieve the above object, the present invention provides a source device for distributing a video stream formed from a plurality of encoded pictures, and receiving the distribution of the video stream from the source device. In a video system having one or a plurality of sink devices that decode and display each included picture, when performing fast reverse playback at N times speed on the source device, an average of pictures M (however, , M> N), one picture is extracted according to the reverse order of the playback time order on the video stream, and is extracted so that the transfer period of each picture is an average M / N display frame period. Special reproduction picture distribution means for sequentially transferring each picture from the source device to the sink device, the sink device Decoding means for sequentially decoding pictures transferred from the source device, and decoding by the decoding means for a picture next to a picture displayed in the immediately preceding display frame cycle in each display frame cycle When the decoded next picture is displayed and decoding of the next picture of the picture displayed in the previous display frame period is not completed, the picture displayed in the previous display frame period is displayed again. Replay picture display processing means.

  According to such a video system, similar to the fast-forward playback video system, fast-rewind playback at various speeds is realized by appropriately setting the ratio of the number of pictures to be transferred and the transfer cycle of each picture. The playback speed is not uniquely limited by the ratio of the number of pictures that can be transferred from the source device to the sink device with respect to the number of pictures in the video stream. In addition, the number of pictures transferred from the source device to the sink device can be suppressed to be smaller than the number of display frame periods in which display by fast reverse playback is performed.

  In order to achieve the above object, the present invention provides a source device for distributing a video stream formed from a plurality of encoded pictures, and receiving the distribution of the video stream from the source device. In a video system having one or a plurality of sink devices that decode and display each included picture, when the 1 / N-times slow playback is performed on the source device, each picture of the video stream is converted to the video stream. Special reproduction picture distribution means for sequentially extracting the extracted pictures from the source device to the sink device so that the extraction period is an average of N display frame periods in accordance with the above reproduction time sequence, A decoding means for sequentially decoding the pictures transferred from the source device; In the display frame cycle, when the decoding by the decoding means for the next picture of the picture displayed in the previous display frame period has been completed, the decoded next picture is displayed, and the previous display frame period is displayed. Special decoding picture display processing means for displaying again the picture displayed in the immediately preceding display frame cycle when decoding of the picture next to the displayed picture is not completed.

  According to such a video system, each picture is displayed such that the display period of each picture is an average of N display frame periods by setting the transfer period of each picture to N display frame periods. Therefore, 1 / N-times slow playback can be realized in a pseudo manner. In addition, the number of pictures transferred from the source device to the sink device can be suppressed to be smaller than the number of display frame periods in which display by slow reproduction is performed.

  In order to achieve the above object, the present invention provides a source device for distributing a video stream formed from a plurality of encoded pictures, and receiving the distribution of the video stream from the source device. In a video system having one or a plurality of sink devices that decode and display each included picture, when performing 1 / N-times reverse-slow playback on the source device, each picture of the video stream is converted to the video Special reproduction picture distribution means for sequentially extracting the extracted pictures from the source device to the sink device so that the extraction is performed in the reverse order of the reproduction time order on the stream and the transfer period is an average of N display frame periods. A decoder that sequentially decodes the pictures transferred from the source device to the sink device. And when the decoding means completes the decoding of the next picture of the picture displayed in the immediately preceding display frame period in each display frame period, displays the decoded next picture, Special decoding picture display processing means for displaying again the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in the display frame period is not completed.

  According to such a video system, similarly to the video system that performs the slow playback, 1 / N-times reverse slow playback can be realized in a pseudo manner by setting the transfer cycle of each picture to an N display frame cycle. it can. In addition, the number of pictures transferred from the source device to the sink device can be suppressed to be smaller than the number of display frame periods for performing display by reverse slow playback.

  Here, in the video system that performs fast-forward playback as described above, the video stream includes an I picture in which a video frame is encoded by intraframe encoding, a P picture in which a video frame is encoded by inter-frame predictive encoding, In the case where a B picture obtained by encoding a video frame by bidirectional interframe predictive coding is included as the picture, the special playback picture distribution means of the source device uses the I picture, the I picture, and the I picture from the video stream. One or more selected P pictures may be extracted so that there is no P picture that is not selected between the previous I picture. In this way, fast-forward playback can be realized without converting the picture type.

  Here, in the above video system, the video stream includes both an I picture in which a video frame is encoded by intraframe encoding, a P picture in which a video frame is encoded by inter-frame predictive encoding, and a video frame. In the case where a B picture encoded by inter-frame predictive encoding is included as the picture, the picture extracted from the video stream is extracted in advance by the special playback picture distribution means of the source device. If the picture is not a P picture encoded by inter-frame predictive encoding using a picture, the picture is converted to a P picture encoded by inter-frame predictive encoding using an I picture or a previously extracted picture. Transfer from the source device to the sink device.In this way, pictures of any picture type in the video stream can be used for special playback.

  In the video system described above, the special reproduction picture distribution means of the source device distributes the picture with a predetermined code added thereto, and the special reproduction picture display processing means uses the immediately preceding frame in each display frame cycle. If the decoding by the decoding means for the picture next to the picture displayed in the display frame period has not been completed, the picture is added only when the code is added to the picture displayed in the immediately previous display frame period. You may make it display again.

  As described above, in the video system in which video data is distributed from the source device to the sink device and the video is displayed on the sink device, special playback at a wider variety of playback speeds can be performed.

Hereinafter, a video system according to an embodiment of the present invention will be described taking application to a DVD video system mounted on an automobile as an example.
FIG. 1 shows the configuration of a DVD video system according to this embodiment.
As shown in the figure, the DVD video system has a source device 1 to which a DVD-Video disc 4 is mounted, and one or a plurality of monitor systems 2 connected to the source device 1 via an in-vehicle LAN 3. Each monitor system 2 includes a sink device 21, a display device 22 that displays video input from the sink device 21, and an audio output device 23 that outputs audio output from the sink device 21. .

Next, FIG. 2 shows an internal configuration of the source device 1 and the sink device 21.
As illustrated, the source device 1 includes a DVD drive 11, a transcoder 12, a multiplexing unit 13 (MUX 13), a source-side LAN interface 14, and a distribution control unit 15.
On the other hand, the sink device 21 includes a sink-side LAN interface 211, a demultiplexing unit 212 (DEMUX 212), a buffer 213, a decoder 214, and a playback control unit 215.
In such a configuration, the DVD drive 11 of the source device 1 reads the video data recorded on the DVD-Video disc 4. Here, the video data includes a video stream (MPEG video stream) including an I picture, a P picture, and a B picture. Here, as described above, an I picture is a picture obtained by intra-coding a video frame, and is a picture that does not require another video frame for decoding. A P picture is a picture encoded by inter-frame coding with a reference frame using a video frame of one picture immediately before the reproduction time as a reference frame among an I picture and another P picture. . The B picture is a picture encoded by inter-frame coding between the I picture and the other P pictures using the video frames of the two pictures immediately before and after the playback time as reference frames. It is.

  In the source device 1, the transcoder 12 performs transcoding for converting the compression rate of the read video data in order to reduce the data rate of the video data, and multiplexes the transcoded video data 13. Output to. The multiplexing unit 13 multiplexes the video data input from the transcoder 12 and the playback control data input from the distribution control unit 15, and transmits the multiplexed data to the in-vehicle LAN 3 via the source-side LAN interface 14 in a broadcast or multicast format.

  Next, the video data distributed from the source device 1 is received by the sink-side LAN interface 211 via the in-vehicle LAN 3 in the sink device 2 and separated into video data and reproduction control data by the demultiplexing unit 212. The separated reproduction control data is sent to the reproduction control unit 215, and the video data is stored in the buffer 213. The video data stored in the buffer 213 is sequentially read and decoded by the decoder 214, and the decoded video is output to the display device 22 and the decoded audio is output to the audio output device 23.

On the other hand, the playback control unit 215 controls the operation of the buffer 213 and the decoder 214 using the playback control data sent from the demultiplexing unit 212.
Hereinafter, a special reproduction operation in such a video system configuration will be described.
The distribution control unit 15 of the source device 1 performs special reproduction distribution processing shown in FIG. 3a for this special reproduction operation.
As shown in the figure, in the special reproduction distribution process, during the normal distribution process (step 302), occurrence of a special reproduction instruction from the user is monitored (step 304).
Here, the normal distribution process is a process performed by the distribution control unit 15 during a period of normal reproduction of video data. In this process, the distribution control unit 15 reads the video stream read from the DVD-Video disc 4. In addition, after transcoding the pictures arranged in the order shown in FIG. 4a1, as shown in FIG. 4a2, each sink apparatus maintains the relationship between the GOP and the picture, which will be described later, in the same order as shown in FIG. 4a2. 21 to control the operation to be distributed to However, the distribution control unit 15 follows the notification value SCR of the system clock STC of the sink device 21 that follows the notification value SCR of the system clock STC of the source device 1 distributed in the video data at the start of normal distribution processing. This is distributed as information SH (system header) indicating what video data distribution timing should be started.

  Here, fn in each figure after FIG. 4 represents the order of the reproduction time order of each picture, and the video stream recorded on the DVD-Video disc 4 is reproduced as shown in FIG. 4a1. The first 13 pictures in the time order are encoded into pictures of IBBPBBPBBPBBP, and the 15 pictures are encoded into pictures of BBIBBPBBPBBPBBP for every 15 pictures after the playback time order. In addition, the first 13 pictures are GOPs in the order of IPBBPBBPBBPBB, and the group for each subsequent 15 pictures is set so that the picture to be the reference frame is located before the picture encoded with reference to the reference frame. The GOP is stored on the DVD-Video disc 4 in the order of IBBPBBPBBPBBPBB and is read out in that order. If only the I and P pictures are seen in the video stream recorded on the DVD-Video disc 4, the I and P pictures are arranged in the order of playback time. Further, if only the B picture is seen in the video stream recorded on the DVD-Video disc 4, the B pictures are arranged in the order of playback time.

  When a video stream in which pictures are arranged in the order shown in FIG. 4a2 is distributed, the decoder 214 of the sink device 21 decodes and displays the video stream at a timing according to the synchronization information SH received earlier. Then, as shown in FIG. 4 a 3, a video in which video frames represented by each picture are arranged in the order of the original playback time is generated and displayed on the display device 22.

Now, referring back to FIG. 3a, in the special reproduction distribution process, if a special reproduction instruction is issued from the user during the normal distribution process (step 302) (step 304), the SEQ code ( (Sequence end code) is added (step 306). When the distribution of the GOP being distributed is completed, the normal distribution process is stopped (step 308).
The extraction is a rule for selecting a picture to be extracted as a picture to be distributed to the sink device 2 in the special reproduction from the video stream recorded on the DVD-Video disc 4 according to the designated special reproduction reproduction speed. A picture rule and a transfer timing rule that defines what timing each picture is distributed are determined (step 310). Details of these rules will be described later.

  Then, the special reproduction picture distribution operation is started (step 312). In this special playback picture distribution operation, the special playback type (fast forward playback, fast reverse playback, slow playback, reverse slow playback, etc.) specified and the extracted picture rule are read out from the DVD-Video disc 4 in accordance with the specified special playback type. Then, a picture is extracted from the video stream, transcoded, an SEQ code is added to all the transcoded pictures, and an operation of delivering the picture to the sink device 21 is controlled according to a predetermined transfer timing rule.

  Then, the occurrence of a special reproduction cancellation instruction from the user is monitored (step 314). If the special reproduction cancellation instruction is generated, the special reproduction picture distribution operation described above is terminated (step 316), and the normal distribution process described above is performed. Is started (step 318), and the processing returns to step 302.

Next, the reproduction control unit 215 of the sink device 21 waits for the reception of the synchronization information SH from the source device 1. If the synchronization information SH is received, the system clock STC of the sink device 2 is distributed according to the synchronization information SH. Start following SCR.
On the other hand, the decoder 214 of the sink device 21 decodes and displays each picture according to DTS / PTS according to the DTS / PTS described by the system clock STC of the source device 1 at the timing of decoding / displaying the picture distributed together with the picture. Control is performed so that the picture is decoded / displayed when the system clock STC of the sink device 21 matches. Here, DTS / PTS is described so that each picture can be correctly displayed in the order of playback time without any trouble by the above operation in normal playback. As a result, as described above, when the video stream in which the pictures are arranged in the order shown in FIG. 4a2 is distributed by the normal distribution process of the sink device 21, the decoder 214 of the sink device 21 has a timing according to DTS / PTS. Then, as shown in FIG. 4a3, a video in which video frames represented by each picture are arranged in the order of the original reproduction time is generated and displayed on the display device 22.

  However, if the next picture to be decoded stored in the buffer 213 is a picture to which the SEQ code is added at the timing when the next picture is to be decoded, the decoder 214 does not depend on DTS / PTS, The picture is immediately decoded and displayed. In addition, when a picture to which an SEQ code is added is received, it is possible to display the last picture in the playback time order among the pictures received so far, and the picture to be displayed next can be decoded and displayed. The process which maintains until it becomes is also performed. In this embodiment, for inter-frame prediction, even when the decoder 214 receives a picture to which an SEQ code is assigned, the decoding of the last picture in the order of reproduction time among the pictures received so far is performed. Upon completion, the decoding sequence is not reset. That is, for P pictures received after a picture to which a SEQ code is assigned, decoding is permitted with reference to a picture received before the picture to which the SEQ code is assigned as a reference frame. On the other hand, the decoding sequence is reset for the B picture by bidirectional inter-frame prediction. That is, for B pictures received after the picture to which the SEQ code is assigned, decoding using the picture received before the picture to which the SEQ code is assigned as a reference frame is prohibited. Discard without doing.

Hereinafter, an operation example of special reproduction by each of such processes will be described.
FIG. 4b shows an example of operation in the case of 15-speed fast forward playback. In this case, the distribution control unit 15 of the source device 1 instructs special playback start (fast forward playback) at the timing of the arrow ST shown in FIG. 4b1. If an SEQ code is added to the last picture f12 of the GOP being distributed, the extracted picture rule is set to all I pictures and the transfer timing rule is set to picture transfer cycle = display frame cycle. Playback picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in the figure, I pictures after the GOP being distributed at the time when a special reproduction start instruction (fast forward reproduction instruction) occurs in the video stream read from the DVD-Video disc 4 are displayed. Then, the data is sequentially transcoded, added with the SEQ code, and distributed to the sink device 21 so that the transfer period becomes the display frame period on average.

  Then, by the reproduction control processing for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the delivered I pictures are sequentially decoded for each display frame period, and as shown in FIG. Displayed every time. As a result, fast-forward playback at 15 times speed is realized.

  Next, when a special playback release instruction is generated at the timing of the arrow ED shown in FIG. 4b1, the distribution control unit 15 of the source device 1 returns to each normal distribution process, and transmits the synchronization information SH and then distributes it last. Each picture is sequentially transcoded and distributed from the first picture of the GOP next to the picture f91.

  On the other hand, when the sync device 21 receives the synchronization information SH, the timing control for starting to follow the SCR of the system timer STC of the sync device 21 is performed, and thereafter normal picture reproduction and display are performed. Until the display of the picture by the operation is resumed, since the SEQ code is added to the f91 transmitted last in the special reproduction picture distribution operation, the display of this f91 is maintained as shown in FIG. 4b2. It will be. Note that the B pictures of f104 and f105 are discarded because they refer to pictures before the reception of the SEQ code, and normal reproduction starts from f106, and the display of f91 is maintained until this display of f106. It will be.

  Next, FIG. 4c shows an operation example in the case of performing fast forward playback at 11.25 times speed. In this case, the distribution control unit 15 of the source device 1 sets the extracted picture rule as shown in FIG. 4c1. For all I pictures, the transfer timing rule is set to picture transfer cycle = 4/3 display frame cycle, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 4c1, after the GOP being distributed when a special reproduction start instruction (fast forward reproduction instruction) occurs in the video stream read from the DVD-Video disc 4, Each I picture is sequentially transcoded, added with a SEQ code, and transmitted so that the average of the picture transfer period is 4/3 display frame period. It should be noted that, for example, as shown in the figure, a picture transfer in which the average transfer period is a 4/3 display frame period is a three-picture transmission sequence in which three pictures are transmitted every display frame period. This is done by repeating at intervals.

  Then, as shown in FIG. 4c2, the decoder 214 of the sink device 21 sequentially decodes the decoded I picture that has been distributed by the reproduction control process for the picture to which the SEQ code is added, and the display frame immediately after the decoding is completed. Displayed in the cycle. Here, the display period of a picture is basically one display frame period. However, if the decoding of the next picture is not completed before the end of the display frame period in which the previous picture is displayed, it is not in time. The display of the picture immediately before the previous picture is extended to the display frame period immediately after the decoding of the picture that has not been made in time. In the case shown in the figure, an event occurs in which the picture delivery is not in time at the start of decoding of the picture once every four display frames. Therefore, once the picture is not in time at the start of decoding once every four display frames. As shown by the dotted frame, the previous picture is displayed for two display frame periods. As a result, pseudo 11.25 times fast-forward playback is realized.

Note that the operation when the special reproduction release instruction is generated is the same as the operation described above.
Next, FIG. 5a shows an operation example in the case of performing 7.5-speed fast-forward playback. In this case, the distribution control unit 15 of the source device 1 sets the extracted picture rule as shown in FIG. 5a1. The I picture and one P picture immediately after the I picture are set, the transfer timing rule is set to picture transfer period = display frame period, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 5 a 1, each of the GOPs being distributed after the GOP being distributed when a special reproduction start instruction (fast forward reproduction instruction) is generated in the video stream read from the DVD-Video disc 4 is generated. The GOP I picture and the first P picture of each GOP are sequentially transcoded, and the SEQ code is added to transmit the picture so that the transfer period of the picture is the average display frame period.

  Then, by the reproduction control processing for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, as shown in FIG. 5a2, the delivered I picture and P picture are sequentially decoded for each display frame period. It is displayed every display frame period. As a result, 7.5-times fast-forward playback is realized.

Note that the operation when the special reproduction release instruction is generated is the same as the operation described above.
Similarly, in the distribution control unit 15 of the source device 1 according to the double speed N of fast-forward playback, the extracted picture rule and the ratio of the number of pictures to be extracted specified by the extracted picture rule to the total picture 1 are 1 By setting so that the average transfer cycle of pictures defined by the picture transfer cycle becomes the M / N display frame cycle with respect to / M, fast-forward playback at N times speed can be realized.

  That is, for example, in the distribution control unit 15 of the source device, if the extracted picture rule is set to I picture and two P pictures immediately after the I picture, and the transfer timing rule is set to picture transfer cycle = display frame cycle, Each picture extracted according to the extracted picture rule as shown in 5b1 is transmitted, and by the playback control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, fast-forward playback at 5 × speed as shown in FIG. 5b2 Is realized.

  Further, in the distribution control unit 15 of the source device 1, if the extracted picture rule is set to I picture and all P pictures, and the transfer timing rule is set to picture transfer cycle = display frame cycle, the extracted picture as shown in FIG. 5c1 Each picture extracted according to the rule is transmitted, and the fast-forward playback at 3 × speed is realized as shown in FIG. 5c2 by the playback control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21.

  Further, in the distribution control unit 15 of the source device 1, if the extracted picture rule is set to I picture and all P pictures, and the transfer timing rule is set to picture transfer cycle = 8/5 display frame cycle, as shown in FIG. Each picture extracted in accordance with the extracted picture rule is transmitted to the picture, and by the reproduction control process for the picture to which the above-mentioned SEQ code is added by the decoder 214 of the sink device 21, fast-forward reproduction at 1.875 times speed is performed as shown in FIG. 5d2. Realized.

  Next, FIG. 6a shows an example of operation in the case of 15-times fast-rewind playback. In this case, the distribution control unit 15 of the source device 1 starts special playback at the timing of the arrow ST shown in FIG. 6a1. When an instruction (fast-rewind playback instruction) is generated, if the SEQ code is added to the last picture f119 of the GOP being distributed, the extracted picture rule is all I pictures, and the transfer timing rule is picture transfer cycle = display frame cycle. To start the special playback picture distribution operation.

  In this special playback picture distribution operation, I pictures before the GOP being distributed when a special playback start instruction (fast reverse playback instruction) occurs in the video stream read from the DVD-Video disc 4 are sequentially recorded. The data is sequentially read out in the reverse order, transcoded, added with the SEQ code, and distributed to the sink device 21 so that the transfer period becomes the display frame period on average.

Then, by the reproduction control processing for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, as shown in FIG. 6a2, the delivered I pictures are sequentially decoded for each display frame period, and each display frame period Displayed every time. As a result, fast reverse playback at 15 times speed is realized.
Note that the operation when the special reproduction release instruction is generated is the same as the operation for the fast-forward reproduction described above.

  Next, FIG. 6b shows an example of operation when performing fast-rewind playback at 11.25 times speed. In this case, the distribution control unit 15 of the source device 1 sets the extracted picture rule for all I pictures and the transfer timing. The rule is set to picture transfer cycle = 4/3 display frame cycle, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 6b1, the GOP being distributed when a special reproduction start instruction (fast reverse reproduction instruction) occurs in the video stream read from the DVD-Video disc 4 is generated. Each previous I picture is sequentially read and transcoded in the reverse order of the recording order, transcoded, added with a SEQ code, and transmitted so that the average of the picture transfer period is 4/3 display frame period.

  Then, as shown in FIG. 6b2, by the reproduction control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the I pictures that have been distributed are sequentially decoded, and the display frame period immediately after the decoding is completed. Is displayed. Here, the display period of a picture is basically one display frame period. However, if the decoding of the next picture is not completed before the end of the display frame period in which the previous picture is displayed, it is not in time. The display of the picture immediately before the previous picture is extended to the display frame period immediately after the decoding of the picture that has not been made in time. In the case shown in the figure, an event occurs in which the picture delivery is not in time at the start of decoding of the picture once every four display frames. Therefore, once the picture is not in time at the start of decoding once every four display frames. As shown by the dotted frame, the previous picture is displayed for two display frame periods. As a result, a pseudo 11.25 times fast reverse playback is realized.

Note that the operation when the special reproduction release instruction is generated is the same as the operation described above.
Next, FIG. 6c shows an operation example in the case of performing 7.5 times fast reverse playback. In this case, the distribution control unit 15 of the source device 1 extracts the extracted picture rule as shown in FIG. 6c1. Is the I picture and one P picture immediately after the I picture, the transfer timing rule is set to picture transfer cycle = display frame cycle, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 6 c 1, when a special reproduction start instruction (fast reverse reproduction instruction) occurs in the video stream read from the DVD-Video disc 4, the pre-GOP distribution is performed. The I picture of each GOP and the first P picture of each GOP are sequentially read and transcoded in the reverse order of the recording order. However, in transcoding, the picture type is converted to an I picture for a P picture. In the illustrated example, f103 and f88 indicated by thick frames are P pictures in which the picture type is converted to an I picture. Then, an SEQ code is added to each transcoded I picture, and transmitted so that the transfer cycle of the picture becomes an average display frame cycle.

  Then, by the reproduction control processing for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the I pictures distributed as shown in FIG. 6c2 are sequentially decoded for each display frame period, and each picture frame period is displayed. Is displayed. As a result, 7.5-times fast reverse playback is realized.

Note that the operation when the special reproduction release instruction is generated is the same as the operation described above.
Similarly, in the distribution control unit 15 of the source device 1 in accordance with the double speed N of fast reverse playback, the ratio of the number of pictures to be extracted that is defined by the extracted picture rule and the number of pictures to be extracted specified by the extracted picture rule to the total picture By setting the average transfer cycle of pictures defined by the picture transfer cycle to 1 / M so as to be the M / N display frame cycle, fast reverse playback at N times speed can be realized.

  That is, for example, in the distribution control unit 15 of the source device 1, if the extracted picture rule is set to two P pictures immediately after the I picture and the I picture, and the transfer timing rule is set to picture transfer cycle = display frame cycle, Each picture extracted in reverse order according to the extracted picture rule as shown in FIG. 6d1 is transmitted after the P picture is converted into an I picture and transmitted by the decoder 214 of the sink device 21 to which the above-described SEQ code is added. As a result of the processing, as shown in FIG.

  Also, in the distribution control unit 15 of the source device 1, if the extracted picture rule is I picture and all P pictures, and the transfer timing rule is set to picture transfer cycle = display frame cycle, the extracted picture rule is as shown in FIG. 7a1. Each picture extracted in reverse order according to the rule is transmitted after converting the P picture to an I picture, and the playback control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21 is as shown in FIG. 7a2. In addition, fast reverse playback at 3 × speed is realized.

  Further, in the distribution control unit 15 of the source device 1, if the extracted picture rule is I picture and all P pictures, and the transfer timing rule is set to picture transfer cycle = 8/5 display frame cycle, as shown in FIG. 7b1 Each picture extracted in reverse order according to the extracted picture rule is transmitted after being converted into an I picture for a P picture, and by the reproduction control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21. As in 7b2, fast forward playback at 1.875 times speed is realized.

  Next, FIG. 8a shows an example of operation in the case of performing a 1/2 × speed slow playback. In this case, the distribution control unit 15 of the source device 1 performs special playback at the timing of the arrow ST shown in FIG. 8a1. When a start instruction (slow playback instruction) is generated, if the SEQ code is added to the last picture f12 of the GOP being distributed, the extracted picture rule is all pictures, the transfer timing rule is picture transfer cycle = 2 display frame cycle To start the special playback picture distribution operation.

  In this special reproduction picture distribution operation, as shown in the figure, all pictures after the GOP being distributed at the time when a special reproduction start instruction (slow reproduction instruction) occurs in the video stream read from the DVD-Video disc 4 are displayed. Then, the transcoding is sequentially performed in the order of the reproduction time. However, in transcoding, the picture type is converted to an I picture for the first picture, to an I picture for the other P pictures and B pictures, or to a P picture using the picture transcoded immediately before as a reference frame. Then, an SEQ code is added to each transcoded I picture or P picture, and transmitted so that the transfer period of the picture becomes an average of two display frame periods.

  Then, by the reproduction control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the delivered I picture or P picture is sequentially decoded as shown in FIG. 8a2, and each two display frame periods are displayed. Is done. As a result, 1 / 2-speed slow playback is realized.

  Next, FIG. 8b shows an operation example in the case of performing 1/4 × slow playback. In this case, the distribution control unit 15 of the source device 1 sets the extracted picture rule to all pictures and the transfer timing rule. The picture transfer cycle is set to 4 display frame cycles, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 8b1, all of the GOPs being distributed after the GOP being distributed at the time of the special reproduction start instruction (slow reproduction instruction) in the video stream read from the DVD-Video disc 4 is generated. Pictures are sequentially transcoded in order of playback time. However, in transcoding, the picture type is converted to an I picture for the first picture, to an I picture for the other P pictures and B pictures, or to a P picture using the picture transcoded immediately before as a reference frame. Then, an SEQ code is added to each transcoded I picture or P picture, and transmitted so that the transfer period of the picture becomes an average of four display frame periods.

  Then, by the reproduction control processing for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the delivered I picture or P picture is sequentially decoded as shown in FIG. 8b2, and is displayed every four display frame periods. Is done. As a result, 1/4 × slow playback is realized.

Similarly, by setting the transfer timing rule to picture transfer cycle = N display frame cycle, 1 / N-times slow playback can be realized for any N.
Next, FIG. 8c shows an operation example in the case of performing 1 / 2-speed reverse slow playback. In this case, the distribution control unit 15 of the source device 1 sets the extracted picture rule to all pictures, and the transfer timing rule. Is set to picture transfer cycle = 2 display frame cycle, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 8 c 1, when a special reproduction start instruction (reverse slow reproduction instruction) occurs in the video stream read from the DVD-Video disc 4, the pre-GOP distribution is performed. All pictures are read sequentially and transcoded in reverse order of playback time. However, the picture type is converted to the I picture for the first picture, the I picture for the other P pictures and B pictures, or the P picture with the picture transcoded immediately before as the reference frame. An SEQ code is added to the I picture or P picture, and the picture is transmitted in the reverse order of the reproduction time so that the picture transfer period is an average of two display frame periods.

  Then, by the reproduction control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the delivered I picture or P picture is sequentially decoded as shown in FIG. Is displayed. As a result, 1 / 2-speed reverse slow playback is realized.

  Next, FIG. 8d shows an operation example in the case of performing 1 / 4-speed reverse slow playback. In this case, the distribution control unit 15 of the source device 1 sets the extracted picture rule to all pictures, and the transfer timing rule. Is set to picture transfer cycle = 4 display frame cycles, and the special reproduction picture distribution operation is started.

  In this special reproduction picture distribution operation, as shown in FIG. 8d1, when a special reproduction start instruction (reverse slow reproduction instruction) is generated in the video stream read from the DVD-Video disc 4, the pre-GOP distribution is performed. All pictures are read sequentially and transcoded in reverse order of playback time. However, the picture type is converted to the I picture for the first picture, the I picture for the other P pictures and B pictures, or the P picture with the picture transcoded immediately before as the reference frame. An SEQ code is added to the I picture or P picture, and the picture is transmitted in the reverse order of the reproduction time so that the picture transfer period is an average of four display frame periods.

  Then, by the reproduction control process for the picture to which the above-described SEQ code is added by the decoder 214 of the sink device 21, the I pictures distributed as shown in FIG. 8d2 are sequentially table-decoded and displayed every 4 display frame periods. The As a result, 1 / 4-speed reverse slow playback is realized.

Similarly, by setting the transfer timing rule to picture transfer cycle = N display frame cycle, 1 / N-times reverse slow-speed playback can be realized for any N.
The embodiment of the present invention has been described above.

It is a block diagram which shows the structure of the DVD video system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the source device and sink device which concern on embodiment of this invention. It is a figure which shows the flowchart of the special reproduction | regeneration delivery process which the DVD video system which concerns on embodiment of this invention performs. It is a figure which shows the example of a fast-forward reproduction | regeneration operation | movement of the DVD video system which concerns on embodiment of this invention. It is a figure which shows the example of a fast-forward reproduction | regeneration operation | movement of the DVD video system which concerns on embodiment of this invention. It is a figure which shows the example of a fast reverse reproduction | regeneration operation | movement of the DVD video system which concerns on embodiment of this invention. It is a figure which shows the example of a fast reverse reproduction | regeneration operation | movement of the DVD video system which concerns on embodiment of this invention. It is a figure which shows the example of slow reproduction operation | movement of the DVD video system which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Source device, 2 ... Monitor system, 3 ... In-vehicle LAN, 4 ... Disk, 11 ... DVD drive, 12 ... Transcoder, 13 ... Multiplexing part, 14 ... Source side LAN interface, 15 ... Delivery control part, 21 ... Sink device, 22 ... display device, 23 ... audio output device, 211 ... sink-side LAN interface, 212 ... demultiplexing unit, 213 ... buffer, 214 ... decoder, 215 ... playback control unit.

Claims (9)

A source device that distributes a video stream formed from a plurality of encoded pictures, and one or more that receives the distribution of the video stream from the source device and decodes and displays each picture included in the video stream A video system having a sink device,
When performing fast-forward playback at N times speed, the source device extracts, on average, one picture from the video stream for each picture M (where M> N) according to the playback time order on the video stream. Special reproduction picture distribution means for sequentially transferring each extracted picture from the source device to the sink device so that the transfer period of each picture is an average M / N display frame period,
The sink device is
Decoding means for sequentially decoding pictures transferred from the source device;
In each display frame period, when decoding by the decoding means for the next picture of the picture displayed in the previous display frame period is completed, the decoded next picture is displayed, and the previous display frame period is displayed. And a special reproduction picture display processing means for displaying again the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in (1) is not completed. A source device that distributes a video stream formed from a plurality of encoded pictures, and one or more that receives the distribution of the video stream from the source device and decodes and displays each picture included in the video stream A video system having a sink device,
In the case of performing fast reverse playback at N times speed, the source device averages one picture per picture M (where M> N) from the video stream in the reverse order of the playback time on the video stream. Special reproduction picture distribution means for sequentially extracting the extracted pictures from the source device to the sink device so that the transfer period of each picture is an average M / N display frame period is extracted according to the order. And
The sink device is
Decoding means for sequentially decoding pictures transferred from the source device;
In each display frame period, when decoding by the decoding means for the next picture of the picture displayed in the previous display frame period is completed, the decoded next picture is displayed, and the previous display frame period is displayed. And a special reproduction picture display processing means for displaying again the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in (1) is not completed. A source device that distributes a video stream formed from a plurality of encoded pictures, and one or more that receives the distribution of the video stream from the source device and decodes and displays each picture included in the video stream A video system having a sink device,
The source device extracts each picture of the video stream according to the playback time order on the video stream when performing 1 / N-times slow playback, so that the transfer period is an average of N display frame periods. Special reproduction picture distribution means for sequentially transferring the extracted pictures from the source device to the sink device;
The sink device is
Decoding means for sequentially decoding pictures transferred from the source device;
In each display frame period, when decoding by the decoding means for the next picture of the picture displayed in the previous display frame period is completed, the decoded next picture is displayed, and the previous display frame period is displayed. And a special reproduction picture display processing means for displaying again the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in (1) is not completed. A source device that distributes a video stream formed from a plurality of encoded pictures, and one or more that receives the distribution of the video stream from the source device and decodes and displays each picture included in the video stream A video system having a sink device,
The source device extracts each picture of the video stream according to an order reverse to the playback time order on the video stream when performing 1 / N-times reverse-slow playback, and the transfer period is an average of N display frame periods. Special reproduction picture distribution means for sequentially transferring the extracted pictures from the source device to the sink device,
The sink device is
Decoding means for sequentially decoding pictures transferred from the source device;
In each display frame period, when decoding by the decoding means for the next picture of the picture displayed in the previous display frame period is completed, the decoded next picture is displayed, and the previous display frame period is displayed. And a special reproduction picture display processing means for displaying again the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in (1) is not completed. The video system of claim 1, comprising:
The video stream is encoded with an I picture in which a video frame is encoded by intra-frame encoding, a P picture in which a video frame is encoded by inter-frame prediction encoding, and a video frame by bidirectional inter-frame prediction encoding. Including the B picture as the picture,
The special playback picture distribution means of the source device extracts one or more selected P pictures from the video stream such that there is no I picture or an unselected P picture between the I picture and the immediately preceding I picture. A video system characterized by: The video system according to claim 3 or 4 , wherein
The video stream is encoded with an I picture in which a video frame is encoded by intra-frame encoding, a P picture in which a video frame is encoded by inter-frame prediction encoding, and a video frame by bidirectional inter-frame prediction encoding. Including the B picture as the picture,
The special playback picture distribution means of the source device, when the picture extracted from the video stream is not an I picture or a P picture encoded by forward interframe prediction encoding using a previously extracted picture, A video system, wherein an I picture or a previously extracted picture is converted into a P picture encoded by inter-frame predictive encoding and transferred from the source device to the sink device. The video system according to claim 1, 2, 3, 4, 5 or 6,
The special reproduction picture distribution means of the source device distributes the picture with a predetermined code added thereto,
The special reproduction picture display processing means displays in the immediately preceding display frame period when the decoding by the decoding means for the next picture of the picture displayed in the immediately preceding display frame period is not completed in each display frame period. A video system, wherein the picture is displayed again only when the code is added to the picture. A source device that distributes a video stream formed from a plurality of encoded pictures, and one or more that receives the distribution of the video stream from the source device and decodes and displays each picture included in the video stream A video playback method for fast-forward playback in a video system having a sink device of
In the source device, when N-times playback is performed, one picture per picture M (where M> N) on the average is extracted from the video stream in accordance with the display order in the N-times playback, Sequentially transferring each extracted picture from the source device to the sink device such that the transfer cycle of the picture is an average M / N display frame cycle;
In the sink device, sequentially decoding pictures transferred from the source device;
In the sink device, when the decoding of the next picture of the picture displayed in the previous display frame period is completed in each display frame period, the decoded next picture is displayed, and the previous display frame is displayed. And a step of re-displaying the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in the period is not completed. A source device that distributes a video stream formed from a plurality of encoded pictures, and one or more that receives the distribution of the video stream from the source device and decodes and displays each picture included in the video stream A video playback method for performing slow playback in a video system having a sink device of
When performing 1 / N double speed playback in the source device, each picture of the video stream is extracted in accordance with the display order on the 1 / N double speed playback, so that the transfer period is an average of N display frame periods. Sequentially transferring the extracted pictures from the source device to the sink device;
In the sink device, sequentially decoding pictures transferred from the source device;
In the sink device, when the decoding of the next picture of the picture displayed in the previous display frame period is completed in each display frame period, the decoded next picture is displayed, and the previous display frame is displayed. And a step of re-displaying the picture displayed in the immediately preceding display frame period when the decoding of the picture next to the picture displayed in the period is not completed.