KR100759777B1 - Playback device and playback method - Google Patents

Abstract

A tuner unit 71 for receiving and demodulating a broadcast signal and outputting a MPEG2-TS (Transport Stream) and a PTS (Presentation Time Stamp) included in a packetized elementary stream (PES) included in the MPEG2-TS 11 are provided. A reproducing unit 76 which reproduces MPEG2-TS according to the time information indicated by the PTS when the storage unit 72 and the identification flag (pts_dts_flag) included in the PES indicate the presence of the PTS; A rewrite unit 51 which controls to rewrite the identification flag of the PTS including the difference to the PTS member when a difference of time information indicated by a plurality of adjacent PTSs exceeds a predetermined value by comparing a plurality of PTSs stored in the storage unit with each other; A reproducing apparatus having a is provided.

Playback device, playback method, MPEG, MPEG2-TS

Description

Playback device and playback method {PLAYBACK DEVICE AND PLAYBACK METHOD}

1 is an explanatory diagram showing an example of a data structure of MPEG2-TS handled by a playback apparatus according to an embodiment of the present invention.

2 is an explanatory diagram showing an example of a data structure of a TS header of MPEG2-TS handled by a playback apparatus according to an embodiment of the present invention.

3 is an explanatory diagram showing an example of a data structure of a packetized elementary stream (PES) of MPEG2-TS handled by a playback apparatus according to an embodiment of the present invention;

4 is a block diagram showing an example of the configuration of a playback apparatus according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an example of a storage state of a PTS buffer for detecting an abnormal PTS of a playback apparatus according to an embodiment of the present invention; FIG.

Fig. 6 is an explanatory diagram showing an example of a storage state of a PTS and a PCR buffer for detecting an abnormal PTS according to an embodiment of the present invention.

Fig. 7 is a flowchart showing an example of flag rewriting processing during abnormal PTS of the playback apparatus according to the embodiment of the present invention.

8 is a flowchart showing another example of a flag rewrite process during abnormal PTS of the playback apparatus according to the embodiment of the present invention.

Fig. 9 is a flowchart showing another example of flag rewriting process during abnormal PTS of the playback apparatus according to the embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

71: tuner

72: buffer for storing MPEG2-TS

73: video PES buffer

74: voice PES buffer

75: recording buffer

76: video decoder

77: voice decoder

78: recording device

79: display

80: speaker

81: Control part (header rewriting part).

The present invention relates to a reproducing apparatus for reproducing an MPEG stream, and more particularly, to a reproducing apparatus and a reproducing method for suspending a PTS process when a PTS (Presentation Time Stamp) of MPEG2-TS is destroyed.

Background Art In recent years, recording and reproducing MPEG streams have become very common, and many devices have been used for recording and reproducing moving picture contents and music information. In this encoded stream, the multiplexed PTS (output designation time) is used, and the stream based on this time performs a reproduction process. However, this PTS may be destroyed during transmission, and a technique for correcting this is known.

That is, Japanese Patent Laid-Open No. 2003-284066 describes a method for rewriting to the correct PTS when the PTS (output designation time) multiplexed in the encoded-stream is not correct, whereby the PTS information is somewhat unstable. Even if it is, original reproduction is possible.

However, especially in the case of a portable TV receiving terminal, the reception situation is often very poor, and the reception situation deteriorates and the PTS may be destroyed. In such a case, according to the technique shown in 2003-284066, when the PTS cannot be corrected even when the PTS is attempted to be corrected, an abnormality in the processing of the decoder occurs, and as a result, recovery becomes difficult, and then the propagation situation is improved. Even if it does, there is a problem that the reproduction processing becomes impossible for a long time.

It is an object of the present invention to report dynamic information, such as the operating mode and the current position information of the transmitter, to the destination receiver at the time of transmission, as well as information on who the call is received from, as well as the state in which the transmitter is placed. It is to provide a mobile phone communication device and a communication method that can also report information.

An embodiment of the present invention includes a tuner for receiving and demodulating a broadcast signal and outputting a MPEG2-TS (Transport Stream); A storage unit for successively storing a plurality of PTSs (Presentation Time Stamps) included in a packetized elementary stream (PES) included in the MPEG2-TS; A playback unit for reproducing the MPEG2-TS according to time information indicated by the PTS when an identification flag (pts_dts flags) included in the PES indicates that the PTS exists; Comparing the plurality of PTSs stored in the storage unit with each other, and when the difference of time information indicated by the plurality of adjacent PTSs exceeds a predetermined value, the identification flag of the PTS including the difference does not exist. And a rerecording portion for controlling to rewrite so as to appear.

(Example)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail with reference to drawings.

The present invention can be implemented, for example, as a portable TV receiving terminal, and an example of the embodiment will be described below with reference to the drawings. 1 is an explanatory diagram showing an example of a data structure of MPEG2-TS handled by a playback apparatus according to an embodiment of the present invention, and FIG. 2 is an example of a data structure of a TS header of MPEG2-TS handled by a playback apparatus. FIG. 3 is an explanatory diagram showing an example of a data structure of a packetized elementary stream (PES) of MPEG2-TS handled by a playback apparatus, and FIG. 4 is a block diagram showing an example of a configuration of a playback apparatus. 5 is an explanatory diagram showing an example of the storage state of the PTS buffer for detecting the abnormal PTS of the playback apparatus, FIG. 6 is an explanatory diagram showing an example of the storage state of the PTS and PCR buffer for the detection of the abnormal PTS; 7 is a flowchart showing an example of a flag rewrite process at the time of an abnormal PTS of the playback apparatus, FIG. 8 is a flowchart showing another example of the flag rewrite process at the time of an abnormal PTS of the playback apparatus, and FIG. 9 is an abnormality of the playback apparatus. PTS City Flag It is a flow chart showing another example of the recording process.

<Playing apparatus according to an embodiment of the present invention>

A playback apparatus which is a TV receiving terminal according to an embodiment of the present invention is an encoded-stream receiver. The reproducing apparatus A, that is, the TV receiving terminal, has a header rewriting function in FIG. 4, and a control unit 81 for controlling the overall operation, and a tuner 71 connected to the antenna as a configuration respectively connected to the control unit 81. And an MPEG2-TS storage buffer 72 to which an MPEG2-TS (Transport Stream) stream is supplied from the tuner 71, and an image PES buffer 73 in which data connected to the MPEG2-TS separated from the MPEG2-TS is stored. ), A video decoder 76 for decoding a video, an audio PES buffer 74 for storing an audio PES, an audio decoder 77 for decoding an audio PES, and a recording buffer 75 for recording received data. And a recording device 78 for performing recording processing, a display 79 connected to a video decoder, and a speaker 80 for outputting audio.

In this configuration, the reproduction apparatus demodulates the radio waves input from the antenna into the MPEG2-TS (Transport Stream) stream in the tuner 71 and is stored in the MPEG2-TS storage buffer 72. The video PES data separated from the MPEG2-TS is stored in the video PES buffer 73 and decoded by the video decoder 76. The voice PES data separated from the MPEG2-TS is also stored in the voice PES buffer 74 and decoded by the voice decoder 77. When recording the received data, the data is stored in the recording buffer 75 and recorded in the recording device 78. The picture decoded by the picture decoder 76 is output when the display output time called a presentation time stamp (PTS) described in the picture PES is reached. Similarly, the voice decoded by the voice decoder 77 is output when the display output time indicated by the PTS described in the voice PES is reached. If this PTS becomes an abnormal value, there is a possibility that the video and audio decoder will not operate normally. In addition, there is a possibility that the data recorded in the state where the PTS is an abnormal value cannot be reproduced correctly at the time of reproduction. Hereinafter, the header processing which is one embodiment of the present invention for PTS error will be described in detail, but first, the data structure of the stream will be described.

(Configuration of MPEG2-TS, etc.)

1 shows the relationship between MPEG2-TS, video PES, and audio PES. MPEG2-TS11 consists of a packet sequence of 1 packet 188 bytes, and a packet consists of a header part 12 and a payload part. In the payload portion, the video PES 13 and the audio PES 31 are divided and stored. Here, the video PES 13 has a PES header 21, video payloads 22 and 23, and the audio PES 31 has a PES header 31 and an audio payload 33. In addition, the video PES buffer 73 and the audio PES buffer 74 shown in FIG. 3 are obtained by extracting and separating the video PES and the audio PES from the MPEG2-TS packet sequence.

Similarly, the configuration of the TS header is shown in FIG. The TS header 12 has a sync byte 41, a PID 42, an adaptive field control 43, and an adaptive field control 44. The adaptive field control 44 further has an adaptive field length 51, a PCR_flag 53, and a PCR (Program Clock Reference) 54.

3 illustrates a structure of a packetized elementary stream (PES). The structure of PES is the same for both video PES and audio PES. The voice PES 14 consists of a header portion called PES header 32 and an elementary stream 33 body called PES packet data bytes. An elementary stream is data obtained by compression-coding video or audio. The PES header 32 is provided with a presentation time stamp (PTS) 65 representing the time to decode the elementary stream in the PES packet data bytes or a decoding time stamp (DTS) 65 representing the time to start decoding. . The video decoder or audio decoder performs decoding start and display of decoded images or output of audio in accordance with this PTS / DTS 65.

If this PTS 65 is not normal, the operation of the decoder may be abnormal. When the radio wave strength received by the antenna of FIG. 3 is weak, MPEG2-TS decoded by the tuner 71 may not be correctly decoded. In this case, the PTS 65 in the MPEG2-TS stream also becomes an outlier, resulting in a problem that the video decoder or audio decoder does not operate normally. As a countermeasure, a process of detecting and correcting the abnormal PTS before sending it to the decoder is performed. The MPEG2-TS storage buffer 72 of Fig. 3 is provided in the receiver to perform this PTS correction.

<Header processing according to an embodiment of the present invention>

The header processing for the PTS abnormality which is one embodiment of the playback apparatus according to the present invention will be described in detail. The abnormal PTS process of the playback apparatus according to the present invention will be described in detail with reference to the flowchart of FIG.

First, when the MPEG2-TS storage buffer 72 is full until the MPEG2-TS data from the tuner is filled (S11), both PCR and PTS from the beginning to the end of the buffer are detected and stored (S12). , S13). When both the PCR and the PTS in the buffer are acquired, it is determined whether or not the PTS is normal (S14). In this case, it is determined whether or not the PTS is abnormal based on past and future PTSs and PCR values (S15).

If it is determined that the PTS is abnormal (S16), the pts_dts_flag of the PES header is rewritten to, for example, "0" (S17). When the determination of all PTSs is finished (S18), the data in the buffer is sent to the video PES buffer 73, the audio PES buffer 74, or the recording buffer 75, and the process proceeds to the reproduction process (S19).

(PTS error detection method)

Here, various methods of PTS abnormality detection will be described in detail using the flowcharts of FIGS. 8 and 9. That is, when an abnormal PTS is detected with reference to the PTS in the buffer of FIG. 5, first, all PTSs included in the MPEG2-TS storage buffer 72 are first extracted. Since the PTS can be given to the PES header, the packet code prefix at the head of the PES header is found. In the PES header, there is a 2-bit flag (pts_dts_flag) indicating that the PTS exists. If the value is "10" or "11", the PTS exists. If the PES header is found, the value of the pts_dts_ flag is examined and the value is obtained if the PTS exists. In FIG. 5, five PTSs (PTS 1, PTS 2, PTS 3, PTS 4, and PTS 5) exist in the buffer. Next, the difference between successive PTSs is calculated. In the MPEG2-TS standard, the difference between PTSs is 700 ms or less. Therefore, when the difference of the PTS exceeds 700 ms or when the PTS value becomes smaller than the previous PTS value, the PTS can be judged abnormally (S31 in Fig. 8). For example, when PTS 1 to PTS 5 were 100 ms, 500 ms, 1500 ms, 1200 ms, and 1700 ms, respectively,

PTS3-PTS2 = 1000ms> 700ms

PTS 4 <PTS 3

Because of this, PTS 3 (1500 ms) can be determined as an outlier.

In addition, when using one frame for one PES here, the specification implemented at 15 frames / sec is suitable. Assuming that the processing in this standard can assume a value of "1/15 sec = 66 msec", it is also possible to assume the lower limit of the PTS to 66 msec. Therefore, as an example, it can be determined that the PTS is regarded as more than the PTS if it exceeds the range of 66 msec to 700 msec.

However, even if these values are shown, the case where the radio wave is actually weak may be considered to be the case where the PTS falls out, and in this case, even if the difference between two adjacent PTSs exceeds 700 ms, it may not be judged as abnormal. have. In such a case, it is appropriate to judge not only the adjacent PTS but also the PTS values in the vicinity thereof. That is, when the difference of time information indicated by a plurality of adjacent PTSs exceeds a predetermined value by comparing a plurality of PTSs stored in the storage unit, not only the PTS including the difference but also the peripheral PTSs of the PTSs differ in time information. It is determined whether or not this predetermined value is exceeded. If it is determined that the error exceeds the predetermined value, the pts_dts_ flag of the corresponding PES header is rewritten to "00".

Accordingly, the decoder determines that there is no PTS. If the PTS is abnormal, the elementary stream is also broken in many cases. However, the decoder does not decode the decoder. However, by rewriting the pts_dts_ flag, which is a PTS flag, with "00", the decoder does not temporarily perform the PTS process. Abnormal operation resulting from it can be prevented. As a result, even if the PTS is destroyed due to the radio wave condition, the decoder does not cause abnormal operation, and it is possible to resume smooth playback processing after the radio wave condition is improved.

(Reference of PCR)

In FIG. 6, a method of detecting an abnormal PTS will be described with reference to PCR. Program clock reference (PCR) is given to MPEG2-TS to correct the reference time of the receiver to the reference time of the broadcasting station. PCR is given to the adaptation field of the TS header as shown in FIG. There is an area called an adaptation field in the TS header, and there is a 2-bit flag (adaptation field control) indicating whether an adaptation field exists in the flag area following the PID. If the adaptation field control is "10" or "11", there is an adaptation field region. In the adaptation field, there is a 1-bit flag (PCR_flag) indicating that the PCR exists, and PCR exists when the PCR_flag is "1".

In FIG. 6, five PCRs of PCR 1, PCR 2, PCR 3, PCR 4, and PCR 5 are included. Although the case where PCR is abnormal can be considered, in order to simplify, PCR shall be correct. Since PCR is provided at intervals of 100 ms or less according to the MPEG2-TS standard, the difference between the PTS and the immediately preceding PCR will not change so much. Therefore, when the difference between the PTS and the PCR greatly changes, for example, exceeding 100 ms, the PTS can be judged abnormally (step S33 in Fig. 9). For example, when PCR 1 to PCR 5 are 200 ms, 250 ms, 300 ms, 350 ms and 400 ms, respectively, and PTS 1 to PTS 5 are 400 ms, 460 ms, 520 ms, 2000 ms and 600 ms, respectively.

PTS 1-PCR 1 = 200 ms

PTS 2-PCR 2 = 210 ms

PTS 3-PCR 3 = 220 ms

PTS 4-PCR 4 = 1650 ms

PTS 5-PCR 5 = 200 ms

This results in the determination that PTS 4 is abnormal. If it is determined that the PTS is abnormal, the abnormal operation due to the PTS control of the decoder can be prevented by rewriting the pts_dts_ flag of the PES header to "00".

That is, a method of correcting the PTS to a normal value in real time when the PTS is abnormal is effective when there is a premise that the receiver is somewhat stable and can receive radio waves. In particular, however, radio wave strength is not always stable in a mobile mobile terminal called a mobile broadcast receiver or a terrestrial one-segment broadcast receiver. When the radio wave strength is weak, it can always happen that MPEG2-TS is not decoded correctly and PTS is abnormal. In such a case, correction is difficult because the adjacent PTS is often broken even when the PTS is corrected in real time. In addition, even if the PTS is corrected to a correct value, the elementary stream (ES) itself is likely to be broken, and thus the result cannot be decoded.

In one embodiment of the present invention, by temporarily storing the MPEG2-TS in the buffer, an abnormality of the PTS can be detected from the PTS or the PCR of the past and the future, and the reliability of the determination of the PTS abnormality can be increased. By rewriting the identification flag to make the stream in which the PTS does not exist, rather than correcting the error, abnormal operation due to PTS control of the decoder can be prevented. Therefore, by the processing above the PTS of this embodiment, the reception of the portable mobile terminal whose radio wave intensity is not stabilized enables the rapid reproduction image display with the improvement of the radio wave situation.

(Other Examples)

In the embodiment described above, the tuner section is provided and the stream has been described using MPEG2-TS as an example. However, the essence of the present invention is, as an example, a storage area for storing a plurality of consecutive time information (Presentation Time Stamps) of information units included in audio image information, and identification information (pts_dts_) indicating whether or not this time information exists. Flag) indicates that an information unit of audio image information exists, a difference between a reproduction unit for reproducing audio image information according to the time information and a plurality of adjacent time information is compared by comparing a plurality of time information stored in the storage unit. When the value is exceeded, the reproducing apparatus controls to suspend PTS processing of the information unit of the audio image information in the rewritten range of the identification information by rewriting the identification information as the time information does not exist. Therefore, the essence is not limited to at least the tuner section and MPEG2-TS, and even an MPEG2-PS or another stream can be equally targeted and can exhibit the same effect.

In the above-described playback apparatus, when receiving a TS stream from a broadcast signal by a portable or mobile receiver, when the radio wave is weak, not only the PTS but also the ES (Elementary Stream) itself are broken, so that even if the PTS is corrected, the playback can be performed by the decoder. Most likely not. In this case, instead of forcibly correcting the PTS, it is possible to cope with an abnormality of the PTS without putting a processing burden on the apparatus by rewriting the identification flag or the like which does not have a PTS. As a result, even if the PTS is destroyed due to the radio wave situation, the abnormal operation of the decoder is not caused, and smooth playback processing can be resumed after the radio wave condition is improved.

Although the skilled person can realize this invention by the various Example described above, it is easier for a person skilled in the art to come up with the various modified example of this Example, and it does not have invention ability, and it applies to various example It is possible to do Accordingly, the present invention affects a wide range that does not contradict the disclosed principles and novel features and is not limited to the above-described embodiments.

Claims (13)

A tuner that receives and demodulates a broadcast signal and outputs a MPEG2-TS (Transport Stream); A storage unit for successively storing a plurality of Presentation Time StamPs (PTSs) included in a Packetized Elementary Stream (PES) included in the MPEG2-TS; A playback unit for reproducing the MPEG2-TS according to time information indicated by the PTS when an identification flag (pts_dts_flag) included in the PES indicates that the PTS exists; Comparing a plurality of PTSs stored in the storage unit with each other, when the difference of time information indicated by a plurality of adjacent PTSs exceeds a predetermined value, the identification flag of the PTS including the difference indicates that the PTS does not exist. Rerecording controls to rewrite Playback device comprising a. The identification flag of the PTS according to claim 1, wherein the rewrite unit includes the difference when a difference of time information indicated by a plurality of adjacent PTSs is compared with each other by comparing a plurality of PTSs stored in the storage unit with each other. To zero, indicating that the PTS does not exist. The data recording apparatus as claimed in claim 1, wherein the rewriting unit compares a plurality of PTSs stored in the storage unit with each other and when the difference of time information indicated by a plurality of adjacent PTSs exceeds a predetermined value, And the PTS around the PTS also rewrites the identification flag based on whether the difference in time information exceeds a predetermined value. The identification flag of the PTS according to claim 1, wherein the rewriting unit compares a plurality of PTSs stored in the storage unit with each other and when the difference of time information indicated by a plurality of adjacent PTSs exceeds 700 msec. Is rewritten to indicate that the PTS does not exist. The apparatus of claim 1, wherein the rewrite unit includes the difference when the difference of time information indicated by the plurality of adjacent PTSs is compared with each other by comparing a plurality of PTSs stored in the storage unit with each other. And rewrite the identification flag of the PTS to indicate that the PTS does not exist. The PTS of claim 1, wherein when the difference of time information indicated by the plurality of adjacent PTSs exceeds a predetermined value by comparing a plurality of PTSs stored in the storage unit with each other, the PTS is determined to be abnormal and stored in the storage unit. And reproducing the identification flag to indicate that the PTS does not exist when it is determined that such an abnormal PTS is a small integer or more in a plurality of PTSs. The apparatus of claim 1, further comprising a second storage unit configured to sequentially store a plurality of program clock references (PCRs) included in a TS header included in the MPEG2-TS. And the rewriting unit obtains the difference between the time information indicated by the PTS and the PCR, and when the value exceeds a predetermined value, judges that the PTS is abnormal and rewrites the identification flag. The apparatus of claim 1, further comprising a second storage unit configured to sequentially store a plurality of PCRs included in a TS header included in the MPEG2-TS. And the rewriting unit judges that the PTS is abnormal when the difference between the PTS and the PCR is 100 msec or more and rewrites the identification flag. A storage unit for storing time information (PTS) of a plurality of consecutive blocks on the basis of the information unit included in the audio image information; A playback unit for reproducing the audio image information according to the time information when the identification information (pts_dts_flag) indicating whether the time information is present indicates that an information unit of the audio image information exists; A rerecording unit for comparing the plurality of time information stored in the storage unit so as to rewrite the identification information to indicate that the time information does not exist when a difference of a plurality of adjacent time information exceeds a predetermined value. Playback device comprising a. 10. The apparatus according to claim 9, wherein the rewrite unit compares a plurality of pieces of time information stored in the storage unit with each other, and when the difference of time information represented by a plurality of adjacent time information exceeds a predetermined value, not only the time information but also the time. And the peripheral time information of the information is also re-recording the identification information based on whether the difference exceeds a predetermined value. Receiving and demodulating a broadcast signal to output MPEG2-TS; Storing a plurality of consecutive PTSs included in the PES included in the MPEG2-TS in a storage unit; Comparing a plurality of PTSs stored in the storage unit with each other, when the difference of time information indicated by a plurality of adjacent PTSs exceeds a predetermined value, the identification flag of the PTS including the difference indicates that the PTS does not exist. Control to rewrite Play method comprising a. 12. The PTS of claim 11, wherein the identification flag of the PTS including the difference does not exist when a difference of time information indicated by a plurality of adjacent PTSs is compared with each other by comparing the stored plurality of PTSs with each other. To zero, so as to indicate no. 12. The PTS of claim 11, wherein when the difference of time information indicated by a plurality of adjacent PTSs exceeds a predetermined value by comparing the stored plurality of PTSs with each other, not only the PTS including the difference but also the PTSs around the PTSs are not limited to time. And reproducing the identification flag based on whether the difference of information exceeds a predetermined value.

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