JP2003101962A - Synchronous reproducing device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform coping in the case that continuity of PCR or PTS is interrupted and to return to synchronous reproduction in the case of AV synchronous reproduction of a stream of MPEG2-TS. SOLUTION: When a value of the PCR or the value of the PTS temporarily become noncontinuous and an overflow of a buffer is detected, reproduction in an AV synchronous reproduction mode is stopped and then the AV synchronous reproduction mode is restored. In this case, when the AV synchronous reproduction is started and the buffer does not cause the overflow, the reproduction is performed in the AV synchronous reproduction mode as it is. When the overflow is detected again, the reproduction is performed in an AV asynchronous reproduction mode. Thus, even when the value of the PTS or the value of the PCR becomes noncontinuous, absolute minimum reproduction is enabled. Thereafter, in the case that the value of the PCR and the value of the PTS gel close, the AV synchronous reproduction is restored and the AV synchronous reproduction is performed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a digital BS.
MPEG2-TS sent by broadcasting or digital CS broadcasting
The present invention relates to a synchronous reproducing apparatus and method suitable for synchronously reproducing video and audio when reproducing a stream of the above, and particularly relates to a case where the continuity of PCR or PTS is interrupted.

[0002]

2. Description of the Related Art Digital satellite broadcasting in Japan is based on ARIB.
(Association of Radio Industrialand Businesses)
It is carried out based on the standard. This ARIB standard is based on European DVB (Digital Video Broadcastin).
It was created based on the standard of g) method, and MPEG (Mov
ing Picture Coding Experts Group) 2-TS (Trans
port stream) system that broadcasts video and audio.

In MPEG2-TS, a plurality of TS packets each having a fixed length of 188 bytes are collected to form a TS stream. The length of the TS packet of 188 bytes is determined in consideration of the consistency with the ATM (Asynchronous Transfer Mode) cell length.

A TS packet is composed of a 4-byte fixed length packet header, a variable length adaptation field and a payload. The packet header contains P
An ID (packet identifier) and various flags are defined. This PID identifies the type of TS packet.

PES (Packetized Elementary Stream) containing individual streams such as video and audio
The packet is divided into a plurality of TS packets having the same PID number and transmitted. The MPEG2 system, for example, is used for encoding the video. For audio encoding, for example, in BS (Broadcast Satellite) digital, the AAC (MPEG2 Advanced Audio Coding) system is used.

[0006] Further, a PE containing data such as subtitles
The S packet is also divided into a plurality of TS packets and transmitted like the video and audio packets.

In such MPEG2-TS, the STC
A PCR (Program Clock Reference) is sent every predetermined time in order to match the (System Time Clock) time.

That is, some TS packets include an adaptation field. The adaptation field is for transmitting additional information regarding the individual stream, and 6-byte PCR is arranged in the optional field.

On the receiver side, the system clock S
TC (System Time Clock) is counted by the STC counter. The time of this STC counter is calibrated based on the time of PCR.

In MPEG2-TS, a time stamp is added to each access unit (for example, each picture in the case of video and each audio frame in the case of audio) in order to establish AV (audio / video) synchronization. . These access units are converted into PES, and the PTS that specifies the playback time is specified in the header of this PES packet.
(Presentation Time Stamp) (or DTS (Decoding T
ime Stamp)) is added.

The time of this PTS is described by the value of STC. On the receiver side, the STC value is the PC from the sender side.
It is advanced in synchronization with R. This STC count value and P
The value of TS is compared, and when the count value of STC and the value of PTS match, display and decoding are started. As a result, AV synchronous reproduction is performed.

As described above, in the MPEG2-TS, the PC
The STC count value advanced in synchronization with R is compared with the PTS value added to the video and audio PES packets, and the STC count value is PT.
By starting display and decoding when the value of S is reached, A
V-synchronized.

By the way, for some reason, PTS or PC
It can happen that R becomes discontinuous. Usually PT
Although the difference between S and PCR is within a substantially constant range, PTS
When PCR or PCR becomes discontinuous, PTS and PCR become significantly different. In the AV synchronization processing, video and audio PES packets are accumulated in a buffer, and P
The STC count value advanced in synchronization with the CR is compared with the PTS value added to the video and audio PES packets, and the STC count value is P.
When the value of TS is reached, the PES packet is read from the buffer, and display and decoding are started. Therefore, if PTS and PCR are significantly different, the value of PTS and the value of STC counter do not match even after a lapse of time, the buffer overflows, and reproduction cannot be performed.

Therefore, conventionally, the capacity of the buffer for storing the PES packet is monitored, and when overflow is detected, reproduction is performed asynchronously with AV. That is, when the overflow of the buffer is detected, the reproduction in the AV synchronization is stopped, and the decoding of the video or audio is immediately started so that the buffer does not overflow. As a result, although the lip sync between the image and the sound cannot be obtained, it is possible to avoid the situation where the image cannot be reproduced.

[0015]

As described above, when the PCR value and the PTS value are discontinuous and largely deviated from each other, the capacity of the buffer for storing the PES packet is monitored to detect an overflow. If this happens, it can be dealt with by performing playback asynchronously with AV.

However, if the PCR or PTS cannot proceed normally, as described above, the PCR value or the PT
In addition to the case where the value of S becomes discontinuous and remains largely deviated, the value of PCR and the value of PTS are temporarily deviated greatly, but after that, the value of PCR and the value of PTS are close to each other. There are cases. In particular, it is often the case that such a stream is included in the playback stream from a device that records and plays back the MPEG2-TS stream as it is on a magnetic tape or HDD.

As described above, the PCR value and the PTS value temporarily deviate greatly, but after that, the PCR value and the PTS value are changed.
When the PCR value and the PTS value are close to each other, AV synchronous reproduction is possible.

However, in the conventional art, once the overflow is detected, the AV asynchronous reproduction mode is uniquely set, and the AV synchronous reproduction mode cannot be restored. For this reason, the PCR value and the PTS value temporarily deviate greatly, but if the PCR value and the PTS value subsequently come close to each other, the AV synchronous playback is possible even though the AV synchronous reproduction is possible. Playback will continue without synchronization.

If an overflow is detected,
It is conceivable to stop the reproduction and then uniquely return to the AV synchronous reproduction mode.

However, when it is uniquely returned to the AV synchronous reproduction mode, in the case of a stream in which the PCR value and the PTS value are largely deviated, overflow or underflow occurs again, and the reproduction is performed even after the recovery processing. It becomes impossible. That is, when PCR >> PTS, overflow again occurs, and when PTS >> PCR, underflow occurs, and in either case, decoding processing becomes impossible,
The screen and sound are not output.

Accordingly, the object of the present invention is to provide MPEG.
When the video and audio of the 2-TS stream are played back synchronously, it is possible to deal with the case where the continuity of PCR or PTS is interrupted, and when the PCR or PTS approaches again, the synchronized playback is carried out again. It is an object of the present invention to provide a synchronous reproducing apparatus and method capable of returning to the above.

[0022]

The present invention includes buffer means for temporarily accumulating an input stream, and decoding means for decoding a stream read from the buffer means. The time stamp indicating the reproduction start time sent to the device is compared with the system reference time. If the system reference time matches the time stamp indicating the reproduction start time, the stream is read from the buffer means to the decoding means and decoded. In the synchronous reproducing apparatus in which the synchronous reproduction mode for synchronously reproducing the stream by decoding the stream by the means is set, if the overflow of the buffer means is detected, the decoding of the stream is stopped, and then the synchronous reproduction of the stream is performed. Whether it can be started and synchronous playback of the stream can be started Once the decision was, synchronized playback can be started,
The synchronous reproducing apparatus is characterized in that it is provided with means for reproducing the stream asynchronously when the synchronous reproduction cannot be started and the overflow of the buffer means is detected again when the synchronous reproduction cannot be started.

According to the present invention, when the input stream is temporarily stored in the buffer means and the stored stream is decoded, the time stamp indicating the reproduction start time sent in the stream and the system reference. When the system reference time matches the time stamp indicating the playback start time, the stream accumulated in the buffer means is read and the read stream is decoded to enable the synchronized playback of the stream. In the synchronized playback method, when the overflow of the buffer means is detected, the decoding of the stream is stopped, and then
Start the synchronized playback of the stream, judge whether the synchronized playback of the stream can be started, and if the synchronized playback can be started, set it to the synchronized playback continuously.If the synchronized playback cannot be started, the buffer means overflows. If it is detected again,
This is a synchronous reproduction method characterized in that the stream is reproduced asynchronously.

According to the present invention, when the PCR value or the PTS value becomes temporarily discontinuous and the buffer overflow is detected, the reproduction in the AV synchronous reproduction mode is stopped, and then the AV synchronous reproduction mode is resumed. Here, if the AV synchronous reproduction is started and the buffer does not overflow, the reproduction is performed in the AV synchronous reproduction mode, and if the overflow is detected again, the reproduction is performed in the AV asynchronous reproduction mode.

Therefore, even if the PTS value and the PCR value are discontinuous, the lip sync cannot be obtained, but the minimum reproduction is possible.

Further, when the PCR value and the PTS value are temporarily deviated largely, but after that, when the PCR value and the PTS value are close to each other, the AV synchronous reproduction is resumed, and A
It is possible to perform V-synchronous reproduction.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention.

In FIG. 1, MPEG is connected to the input terminal 10.
A 2-TS stream is provided. The TS stream from the input terminal 10 is supplied to the demultiplexer 11. The demultiplexer 11 separates the desired video PES packet and audio PES packet from the TS stream from the input terminal 10.

The video PES packet separated by the demultiplexer 11 is supplied to the video buffer 12. The audio PES packet separated by the demultiplexer 11 is supplied to the audio buffer 19.

Further, the demultiplexer 11 extracts the PCR value in the adaptation field of the TS packet at every predetermined timing. That is, MPE
The G2-TS TS packet has a fixed length of 188 bytes, and includes a header and a payload. In the adaptation field of the header, P is set every predetermined timing.
CR is added. This PCR is the demultiplexer 11
It is extracted with. The extracted PCR is STC counter 1
8 are supplied.

The TS stream supplied to the input terminal 10 is formed by demodulating a received signal of digital BS broadcast or digital CS broadcast, for example. Also, M
PEG2-TS stream directly to magnetic tape or HDD
There is known a recording / reproducing device for recording / reproducing on / from (Hard Disk Drive). The input terminal 10 may be supplied with a TS stream reproduced from such a recording / reproducing apparatus.

The STC counter 18 is, for example, a 33-bit counter that operates as a synchronization reference counter. The STC counter 18 is counted in steps of, for example, 90 Hz, with the PCR value sent at each predetermined timing as an initial value. The output of the STC counter 18 is the video decoding unit 14 and the audio decoding unit 2.
1 is supplied.

The video PES packet separated by the demultiplexer 11 is temporarily stored in the video buffer 12. Video PES stored in this video buffer 12
The packet is controlled by the video decoding control unit 13,
It is supplied to the video decoding unit 14.

In the video decoding section 14, for example, MPE
G2 system image expansion processing is performed and video data is decoded. The decoded video data is supplied to the video output control unit 16 via the frame buffer 15 and output from the video output terminal 17. The output of the video output terminal 17 is supplied to a monitor (not shown).

The audio PES packet separated by the demultiplexer 11 is transferred to the audio buffer 19
Is temporarily stored in. The audio PES packet accumulated in the audio buffer 19 is controlled by the audio decoding control unit 20 to be decoded by the audio decoding unit 21.
Is supplied to.

In the audio decoding section 21, for example, A
AC audio decompression processing is performed and audio data is decoded. The decoded audio data is supplied to the audio output control unit 23 via the PCM buffer 22 and output from the audio output terminal 24. The audio signal from the audio output terminal 24 is supplied to a speaker (not shown).

In the MPEG2-TS system, the arrival time from the transmission of video and audio packets to the reception and the amount of data vary. Therefore, if the received video and audio packets are directly decoded and reproduced, AV synchronization cannot be achieved. Therefore, for each video and audio access unit, the PTS designating the reproduction time is added to the header of the PES packet.
This PTS value is compared with the STC count value, and PT
AV synchronization is established by starting reproduction when the value of S and the count value of STC match.

That is, in the normal state, the video decoding section 14 and the audio decoding section 21 are in the AV synchronous reproduction mode. In the AV synchronous playback mode, the video decoding unit 14 compares the STC count value and the video PTS value, and if the STC count value and the PTS value match, the video buffer 1
The video data is read from 2, and the decoding of the video data is started. In addition, the audio decoding unit 21 compares the STC count value with the audio PTS value, and if the STC count value and the PTS value match, audio data is read from the audio buffer 19 and the audio data is read. Data decoding is started. In this way, AV synchronization is established.

As described above, in the AV synchronous reproduction mode, S
By comparing the TC count value with the PTS value sent in addition to the video and audio PES packets and starting display and decoding when the STC count value reaches the PTS value, AV synchronization is achieved. Has been taken.

However, the PCR value and the PTS value may become discontinuous for some reason. P
If the CR value or PTS value becomes discontinuous, the PCR value or PTS value will differ greatly, and even if time elapses, ST
This means that the count value of C does not match the value of PTS. In this case, since the video buffer 12 and the audio buffer 19 overflow, AV synchronous reproduction becomes difficult.

Therefore, in the embodiment of the present invention, when the overflow of the video buffer 12 or the audio buffer 19 is detected, the overflow of the video buffer 12 or the audio buffer 19 is prevented.
The reproduction in the AV synchronous reproduction mode is not performed.

Further, the PCR value and the PTS value may temporarily deviate greatly, but after that, the PCR value and the PTS value may approach each other. If the PCR value and the PTS value are close to each other, AV synchronous reproduction is possible.

Therefore, in the embodiment of the present invention, the PC
When the value of R or the value of PTS becomes temporarily discontinuous and overflow of the video buffer 12 or the audio buffer 19 is detected, the reproduction in the AV synchronous reproduction mode is stopped,
Then, return to the AV sync playback mode, where A
If V sync playback is started and the video buffer 12 and audio buffer 19 do not overflow, A
The reproduction is performed in the V-synchronous reproduction mode, and when the overflow is detected again, the reproduction is performed in the AV asynchronous reproduction mode.

The processing at this time will be specifically described. In the following description, the processing in the audio decoding control unit 20 will be described, but the processing in the video decoding control unit 13 is substantially the same.

FIG. 2 shows the relationship between the passage of time and changes in the values of PTS and PCR, the horizontal axis shows the passage of time, and the vertical axis shows the values of PTS and PCR. Under normal conditions, the values of PCR and PTS change linearly, and P
The difference between the CR value and the PTS value is substantially constant.

FIG. 2A shows an example in which the PTS value is discontinuous for some reason. In this example, at time D1, PT
The value of S becomes discontinuous, the value of PTS increases from time D1, and the value of PTS and the value of PCR are greatly separated.

In this case, AV synchronization reproduction can be performed before the time D1 at which the PTS value becomes discontinuous, but after the time D1, the PTS value and the PCR value are considerably open, and as it is, , Audio buffer 1
9 overflows.

FIG. 2B shows an example in which the PCR value is discontinuous for some reason. In this example, PC at time D2
The value of R becomes discontinuous, the value of PCR becomes smaller from the time D2, and the value of PTS and the value of PCR are greatly separated.

Also in this case, the AV synchronous reproduction can be performed before the time D2 when the PTS value becomes discontinuous, but after the time D2, the PTS value and the PCR value are considerably open and remain as they are. Then, audio buffer 1
9 overflows.

As shown in FIGS. 2A and 2B, when PTS or PCR discontinuity occurs and this discontinuity continues, processing as shown in FIG. 3 is performed.

First, time D1 in FIG. 2A or 2B.
Alternatively, before D2, the reproduction is performed in the AV synchronous reproduction mode.

When an overflow occurs in the audio buffer 19 after time D1 or D2, an overflow detection signal is sent from the audio decoding unit 21 to the audio decoding control unit 20 (step ST
1).

The detection of overflow here is
This means that the audio buffer 19 will soon completely overflow, including the state immediately before the overflow. Near / full information is output from the audio buffer 19, and it is known from this near / full information that overflow is likely to occur.

Next, the audio decoding control section 20
When the overflow detection signal from the audio buffer 19 is received, the audio decoding unit 2 receives the overflow detection signal.
A decode stop signal is issued for 1 (step ST2).

When the audio decoding unit 21 receives the decoding stop signal from the audio decoding control unit 20, the audio decoding unit 21 stops the current decoding and waits for an instruction from the audio decoding control unit 20. After this, the audio decoding control unit 20
A playback start command in the AV synchronous playback mode is issued to the device 1 (step ST3).

The audio decoding unit 21 receives the reproduction start command in the AV synchronous reproduction mode from the audio decoding control unit 20, and reproduces in the AV synchronous reproduction mode.
If AV synchronization is achieved and decoding is started, the audio decoding unit 21 sends a decoding start signal to the audio decoding control unit 20. If it cannot be decoded, the decoding start signal is not sent.

In the case of FIG. 2A or 2B, the value of PCR and the value of PTS are far apart from each other after time D1 or D2, and AV synchronous reproduction cannot be performed after time D1 or D2. . Therefore, the decoding start signal is not sent from the audio decoding unit 21 to the audio decoding control unit 20. Then, in this case, overflow again occurs.

When AV synchronous reproduction cannot be performed and overflow occurs again in the audio buffer 19, the audio decoding unit 21 sends an overflow detection signal to the audio decoding control unit 20 (step ST
4).

Next, the audio decoding control section 20
When the overflow detection signal from the audio decoding unit 21 is received, a decoding stop signal is issued to the audio decoding unit 21 accordingly (step ST5).

Upon receiving the decoding stop signal from the audio decoding control unit 20, the audio decoding unit 21 stops the current decoding and waits for an instruction from the audio decoding control unit 20.

Here, the audio decoding control unit 20
2A is based on the phenomenon that the overflow detection signal is received without receiving the decoding start signal from the audio decoding unit 21.
Alternatively, as shown in FIG. 2B, it is determined that the relationship between the PCR and the PTS remains largely deviated. In this case, the audio decoding control unit 20 gives the audio decoding unit 21 an instruction to perform decoding in the non-AV synchronous reproduction mode (step ST6).

By controlling in this way, the audio decoding section 21 can control the audio buffer 1 for AV synchronization.
Decoding can be started without having to store the stream in 9.

Finally, when the audio decoding section 21 starts the reproduction in the non-AV synchronous reproduction mode, it issues a decoding start signal to the audio decoding control section 20 to inform it that the decoding has started (step S).
T7).

By the above processing, as shown in FIG. 2A or FIG. 2B, the voice output can be obtained even for the illegal input in which the PTS and the PCR are constantly deviated largely at a certain time. The reproduction quality is improved as compared with the case where the output is impossible.

Next, as shown in FIG. 4, PTS or P
A process will be described in the case where CR discontinuity occurs, the values of PTS and PCR differ greatly, and then the difference between PTS and PCR approaches again. In this case, the processing shown in FIG. 5 is performed.

In this example, only the audio decoding control unit 20 will be described, but the processing in the case of the video decoding control unit 13 is substantially the same.

Before time D3 in FIG. 4, it is assumed that the AV synchronization processing has been performed. When an overflow occurs in the audio buffer 19 after time D3, the audio buffer 19 is instructed by the audio decoding control unit 2
An overflow detection signal is sent to 0 (step ST11).

Next, the audio decoding control section 20
When the overflow detection signal from the audio buffer 19 is received, the audio decoding unit 2 receives the overflow detection signal.
A decode stop signal is sent to 1 (step S
T12).

When the audio decoding unit 21 receives the decoding stop signal from the audio decoding control unit 20, the audio decoding unit 21 stops the current decoding and waits for an instruction from the audio decoding control unit 20. After this, the audio decoding control unit 20
A decoding start command in the AV synchronous reproduction mode is issued to the signal 1 (step ST13).

At this time, the audio decoding section 21
When the AV synchronization is established and the decoding is started, the decoding start signal is issued to the audio decoding control unit 20. If the decoding cannot be started, the decoding start signal is not issued.

In the case of the input stream as shown in FIG. 4, as described above, once at time D3 to time D4, P
Even if there is a large difference between the value of TS and the value of PCR, the two become close again after time D4, so if the time between time D3 and time D4 is, for example, about several 100 ms, then AV Even if the decoding start setting is performed in the synchronous reproduction mode, the decoding can be restarted without overflowing the buffer. In this case, the audio decoding unit 21
Issues a decoding start signal to the audio decoding control section 20 in order to inform the audio decoding control section 20 of the start of decoding (step ST14).

The audio decoding control unit 20 determines that the audio buffer 19 has not overflowed because the decoding start signal is received from the audio decoding unit 21. That is, it is determined that the AV synchronization is established, and thereafter, additional control is not performed, and the reproduction is continued in the AV synchronization mode.

As described above, during the decoding process, the buffer overflows, and when the decoding recovery process of the AV decoder is performed next, by restarting the decoding in the AV synchronous reproduction mode, as shown in FIG. And P
In the case where there is a large deviation from CR, it becomes possible to return to AV synchronous reproduction.

Although the audio processing has been described in the above example, the basic operation is the same in the case of video processing. Strictly speaking, P indicating the display processing time
The TS and the DTS indicating the decoding start time may be used separately, but it goes without saying that the value of the DTS and the value of the STC counter may be compared to perform decoding.

Further, in the above-mentioned example, the explanation was made with the MPEG2-TS, but the present invention can be similarly used in the system of MPEG1 or H261 (international standard recommendation relating to video conference, recommendation number H.261).

[0076]

According to the present invention, the value of PCR and PTS
When the value of is temporarily discontinuous and a buffer overflow is detected, playback in AV synchronous playback mode is stopped, and then AV synchronous playback mode is resumed, where AV synchronous playback is started and the buffer is restarted. If the overflow does not occur, the playback is performed in the AV synchronous playback mode, and if the overflow is detected again, the playback is performed in the AV asynchronous playback mode.

Therefore, even if the PTS value and the PCR value become discontinuous, the lip sync cannot be obtained, but the minimum reproduction is possible.

Further, when the PCR value and the PTS value are temporarily deviated largely, and then the PCR value and the PTS value are close to each other, the AV synchronous reproduction is resumed, and A
It is possible to perform V-synchronous reproduction.

[Brief description of drawings]

FIG. 1 is a block diagram of an example of a reproducing apparatus to which the present invention is applied.

FIG. 2 is a graph used to describe an embodiment of the present invention.

FIG. 3 is a sequence diagram used to describe an embodiment of the present invention.

FIG. 4 is a graph used to explain an embodiment of the present invention.

FIG. 5 is a sequence diagram used for describing the embodiment of the present invention.

[Explanation of symbols]

10 ... Input terminal, 11 ... Demultiplexer, 1
2 ... video buffer, 13 ... video decoding control unit, 14 ... video decoding unit, 15 ... frame buffer, 16 ... video output control unit, 17 ...
Video output terminal, 18 ... STC counter, 19 ...
Audio buffer, 20 ... Audio decoding control unit, 21 ... Audio decoding control unit, 21 ...
..Audio decoding unit, 22 ... PCM buffer, 23 ... Audio output control unit, 24 ... Audio output terminal

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 7/081 H04N 7/08 101 // H04J 3/00 F term (reference) 5C053 FA20 FA21 FA23 GB06 GB11 GB38 HA04 HA33 JA07 JA21 JA26 KA05 LA05 5C063 AA01 AB03 AB07 AC01 AC05 CA14 CA34 DA05 DA07 5K028 AA14 BB04 KK03 KK32 MM12 MM17 NN04 NN22 NN23 5K047 AA03 AA11 AA18 CC08 GG44 GG45 HH11

Claims (10)

[Claims] 1. A buffer means for temporarily accumulating an input stream, and a decoding means for decoding a stream read from the buffer means, the decoding means being sent in the stream. The time stamp indicating the reproduction start time is compared with the reference time of the system. When the reference time of the system matches the time stamp indicating the reproduction start time, the stream is read from the buffer means to the decoding means, In the synchronous reproducing apparatus in which the synchronous reproducing mode for synchronously reproducing the stream can be set by decoding the stream by the decoding means, when the overflow of the buffer means is detected, the decoding of the stream is stopped, and next, Start the synchronized playback of the above stream, and If it is possible to start the synchronized playback of the ream, and if the synchronized playback can be started, set to the synchronized playback continuously, and if the synchronous playback cannot be started and the overflow of the buffer means is detected again. A synchronous reproducing apparatus characterized by comprising means for reproducing the stream asynchronously. 2. The synchronous reproducing apparatus according to claim 1, wherein the stream is an MPEG2-TS stream. 3. The time stamp indicating the reproduction start time is added to the PES packet sent in the stream by the PTS.
The synchronous playback device according to claim 1, wherein the synchronized playback device is inserted as. 4. The synchronous reproducing apparatus according to claim 1, wherein the reference time of the system is generated from an STC counter that advances in synchronization with time information inserted as PCR in the stream. 5. The stream is a stream for transferring video and audio PES packets, and the synchronous reproduction is reproduced in synchronization with reproduction of the video and reproduction of the audio. The synchronous playback device described in. 6. A time stamp indicating a reproduction start time sent in the stream when the inputted stream is temporarily accumulated in a buffer means and the accumulated stream is decoded, and a system standard. When the reference time of the system is compared with the time stamp indicating the reproduction start time, the stream accumulated in the buffer means is read and the read stream is decoded to compare the time with the time. In the synchronous reproduction method capable of synchronous reproduction, when the overflow of the buffer means is detected, the decoding of the stream is stopped, the synchronous reproduction of the stream is started, and the synchronous reproduction of the stream can be started. If it is possible to start the above synchronized playback, determine whether And, when the overflow of the buffer means can not be the synchronized playback start is detected again, synchronized playback method is characterized in that so as to reproduce the stream asynchronously. 7. The synchronized reproduction method according to claim 6, wherein the stream is an MPEG2-TS stream. 8. The time stamp indicating the reproduction start time is added to the PES packet sent in the stream by the PTS.
7. The synchronized reproduction method according to claim 6, which is inserted as. 9. The synchronous reproduction method according to claim 6, wherein the reference time of the system is generated from an STC counter that advances in synchronization with time information inserted as PCR in the stream. 10. The stream is a stream for transferring PES packets of video and audio, and the synchronous reproduction is reproduced in synchronization with reproduction of the video and reproduction of the audio. Synchronous playback method described in.