JP2006217322A - Recording and reproducing apparatus having correction function of management information of mpeg2 transport stream - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correct management information to be recorded and AV data so as to be coincident when an attribute provided by an SIT (System Information Table) or a PMT (Program Management Table) being multiplexed management information is different from the attribute of actual AV data in the case of recording a broadcasted MPEG transport stream. <P>SOLUTION: A recording and reproducing apparatus is provided with a reception part for receiving the management information and the AV data, a decoding part for decoding the AV data and a recording control part for recording the management information and the AV data to a recording medium. The apparatus decodes the MPEG transport stream simultaneously with recording, and compares the decoding result with the management information of the stream. When the management information is different from the decoding result, the apparatus corrects a part of the management information with the decoding result and thereafter records it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for recording / reproducing a broadcast MPEG-2 transport stream.

  In recent years, with the start of digital broadcasting in Japan, broadcasting based on the MPEG2 transport stream adopted in the ARIB standard has come into operation. At the same time, a recording / reproducing apparatus using this MPEG2 transport stream using a large-capacity hard disk drive or an optical disk has been developed.

  In these recording / playback apparatuses, at the time of recording, simultaneously with the AV data body, video and audio attribute information (video format, resolution, aspect ratio, audio format, number of audio channels) of the AV data is generated and recorded as management information. However, in an apparatus for recording an MPEG2 transport stream without re-encoding, components in SIT (System Information Table), which is multiplexed management information defined in the ARIB broadcast standard It is acquired from a descriptor, a PMT (Program Management Table), etc. (see Patent Document 1).

  However, since these pieces of management information are inserted at arbitrary values on the broadcasting station side and do not necessarily contain correct management information, when attribute information is generated using these, the recorded AV data and The attribute information may not match.

  In Blu-ray Disc ReWritable Format adopted as a data recording standard in Blu-Ray Disc, which is one of large-capacity discs that can record a digital broadcast stream without re-encoding, the recorded stream body Are described, and the clip information data holding the information of the stream is described.

  This clip information data includes all the video and audio attributes (video format, resolution, aspect ratio, audio format, number of audio channels) included in the stream data, called stream coding information for each video and audio of the stream data. The described descriptor is stored so that the attribute information of the stream data can be known without decoding the stream data. This stream coding information is included in the program information descriptor in the clip information.

  In normal stream data decoding, without using this attribute information, decoding is performed according to the format of MPEG data, output devices such as a display are set from the decoding result, and video and audio are reproduced. However, this causes problems such as it takes time to start playback and the head part cannot be output correctly. Therefore, before starting decoding, it is common to read out attribute information necessary for output from the management information portion in advance and make appropriate settings for the output device (see Patent Document 2).

  In addition, some of these digital recorders have functions such as displaying recorded program information without playing them, in which case the attribute information in the recorded stream coding information is read out, Used for display.

In addition, seamless playback (see Patent Document 3), which performs smooth continuous playback without changing the settings of the output device and decoding device in a continuous stream having the same attribute information, was recorded without re-encoding. In determining whether it is possible in the stream, the management information is very useful. Therefore, correct information should be written in the clip information part.
Japanese Patent Laid-Open No. 11-220692 JP 2002-251830 A JP 2002-320201 A

  However, in this Blu-ray Disc Rewritable Format, attribute information (video format, resolution, aspect ratio, audio format, number of audio channels) described in the clip information data and a predetermined area defined in the MPEG format ( Match the video format / resolution / aspect ratio information described in the sequence header), the audio format (linear PCM / AC-3 / DTS / AAC), and the content of the number of audio channels in each format. It is not stipulated that the attribute information inherent to the stream data is not written in the stream coding information part of the clip information when data is created or when the wrong data is intentionally created. A situation will occur .

  When playing back data that does not match the stream information and clip information, if the video output device or audio output device is set according to the clip information before decoding the stream data, the result that should be output The problem that cannot be obtained occurs.

  Further, when displaying and notifying the attribute information of the stream to the user, if the display is performed with reference to only the clip information without decoding, there is a problem that wrong information is displayed.

A receiving unit for receiving management information and AV data; a decoding unit for decoding AV data; and a recording control unit for recording the management information and the AV data on a recording medium. When the attribute information of the AV data is compared with the management information and the management information is different from the attribute information, the management information is replaced with the attribute information and recorded on the recording medium.

  Even in a stream holding incorrect management information, correct management information can be obtained before decoding by correcting the management information at the time of recording, and the output device before decoding can be set correctly. become able to do.

  In addition, when two or more stream data attribute information obtained in advance is the same, it is possible to prevent malfunctions in seamless playback in which continuous decoding is performed and playback is performed as a continuous stream. .

  Also, in the case of a stream that does not change in the number of audio channels in the management information but changes in the actual stream, the change point of the program and CM is detected by correcting the number of audio channels in the management information according to the decoding result. You can also use it.

  In the present invention, the video information compressed from the video data and the audio information compressed from the audio data are not matched with the video / audio data recorded in the recording format having the management information including the video / audio attribute information. The data is corrected.

  In the management information of the AV data body called sequence header in the MPEG stream data, it is stipulated that the correct value is stored according to the standard. Therefore, when decoding is correctly completed at the time of AV data decoding, from the decoding result The obtained attribute information is compared with the attribute information included in the management information. If the management information is different from the decoding result, it is understood that the management information part is wrong. At this time, if the management information part is corrected and recorded in the storage unit, the correct management information can be obtained without re-decoding the recorded AV data.

  If decoding cannot be completed correctly, the information in the sequence header may not be correct, so the attribute information in the clip information is not corrected.

  Hereinafter, embodiments of the present invention will be described.

(Embodiment)
FIG. 1 is a system configuration diagram of an MPEG2 transport stream recording / reproducing apparatus. Arrows indicate the flow of data.

  The recording / reproducing apparatus according to the present invention includes a tuner device unit 10 that receives a broadcast MPEG2 transport stream, and a data separation unit that separates the multiplexed MPEG2 transport stream into a management information portion and an AV data portion. 20, the separated AV data is transferred to the decoder and the recording control unit 50, and at the same time, the viewing control unit 30 is transferred to the recording control unit, and the AV data transferred from the viewing control unit 30 is decoded and reproduced. The decoder control unit 40 for notifying the recording control unit 50 of the decoding result, the AV data and the management information transferred from the viewing control unit 30, and the decoding result from the decoder control unit 40 are received and stored in the recording medium. It comprises a recording control unit 50 for recording.

  An outline of the operation of the recording / reproducing apparatus configured as described above will be described with reference to FIG. First, a broadcast wave is received (S50), AV data included in the broadcast wave is decoded (S51), and management information included in the broadcast wave is acquired (S52). Then, it is determined whether or not the decoding result and the management information match (S53). If they do not match, the management information is corrected based on the decoding result, and the corrected management information is stored in the storage unit (S54).

  Next, a detailed operation will be described with reference to FIGS. First, the multiplexed MPEG2 transport stream received by the tuner unit 10 is transferred to the data separation unit 20 (S10), and the data separation unit 20 receiving the multiplexed MPEG2 transport stream receives the MPEG2 transport stream. After the port stream is separated into AV data and management information, it is held on the memory, and the viewing control unit 30 is notified of the location where each data is stored. Upon receiving the notification, the viewing control unit 30 transfers the AV data to the decoder control unit 40 and the recording control unit 50, and transfers the management information to the recording control unit 50 (S11). The decoder control unit 40 that has received the AV data performs decoding in accordance with the format standard of the transferred AV data (S12). If the decoding is correctly performed, the AV attribute information (video format) included in the decoding result is obtained. The resolution, aspect ratio, audio format, and number of audio channels) are notified to the recording control unit 50 (S14). The recording control unit 50 that has received the decoding result from the decoder control unit 40 compares the decoding result with the management information transferred from the viewing control unit 30 (S20), and the AV attribute information and the management information included in the decoding result are compared. When there is a difference from the AV attribute information included, the management information is overwritten and corrected by the decoding result and recorded. At this time, if the decoder control unit 40 is decoding a stream different from the stream to be recorded (for example, when data is transferred from a viewing control unit of another system), this is notified to the recording control unit. The recording control unit 50 records the management information received from the viewing control unit 30 as it is without correction. As a result, the occupation of the decoder control unit during recording can be prevented.

  On the other hand, if the decoding cannot be completed correctly, the recording control unit 50 is notified that the decoding has not been completed correctly (S15). If the decoding cannot be completed correctly, the recording control unit 50 records the management information received from the viewing control unit 30 without modification.

  The procedure for overwriting management information is as follows. First, it is determined whether or not the video format is the same as the clip information (S21). If the video format is not the same, the video format in the management information section is corrected to a decoding result (S22). Similarly, it is determined whether the resolution, aspect ratio, audio format, and number of audio channels are the same as the clip information (S23, S25, S27, S29). If they are not the same, the resolution, aspect ratio, audio of the management information section is determined. The format and the number of audio channels are corrected to the decoding result (S24, S26, S28, S30).

  FIG. 6 shows the format of clip information in the Blu-ray Disc ReWrite Format, where (a) is the data structure of the clip information, (b) is the data structure of the program information included in the clip information, and (c) is the program information. Shows the data structure of the stream coding information included in. Since the program information of (b) is defined for each stream included in the disc, when there are a plurality of streams, the program information exists accordingly.

  The information video format, resolution, aspect ratio, audio format, and number of audio channels described above are information included in the stream coding information in the program information in the clip information, and when writing to a Blu-ray disc, Recorded in this data structure.

  As described above, since descriptors describing AV attributes of all video and audio included in the stream data are stored, the attribute information of the stream data can be known without decoding the stream data. ing.

  Note that the recording control unit 50 may record the transport stream received by broadcasting as it is, or may record the decoded data by re-encoding or the like.

  If there is a difference between the attribute information included in the management information received from the broadcast wave and the attribute information obtained by decoding the AV data, the AV data is decoded instead of the attribute information included in the management information. The attribute information obtained in this manner is recorded. At this time, information (marker or the like) indicating that there is a difference in the attribute information may be recorded at the same time.

  Alternatively, a video / audio attribute information switching point may be detected, and a marker may be recorded there.

  Also, in the case of a stream that does not change in the number of audio channels in the management information but changes in the actual stream, the change point of the program and CM is detected by correcting the number of audio channels in the management information according to the decoding result. You can also use it.

  In the present embodiment, the broadcast wave is received and the AV attribute information in the management information included in the broadcast wave is compared with the AV attribute information obtained by decoding the AV data, but the recording medium is reproduced. In this case, the present invention can be realized. In this case, the AV attribute information in the management information included in the recording medium may be compared with the AV attribute information obtained by decoding the AV data.

  Not only an MPEG transport stream in Blu-Ray ReWritable Format, but also a system for recording / reproducing video / audio data in which actual data and management information are separated and inconsistency is recognized to occur. Can also be applied.

Block diagram of recording / reproducing apparatus of the present invention Flow chart showing the operation from data reading to decoding result acquisition Flowchart of comparison operation between decoding result and clip information Clip information change flowchart The flowchart which shows the outline | summary of operation | movement of the reproducing | regenerating apparatus of this invention. Diagram showing the data structure of clip information

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tuner part 20 Data separation part 30 Viewing control part 40 Decoder control part 50 Recording control part

Claims (6)

A receiving unit for receiving management information and AV data;
A decoding unit for decoding the AV data;
A recording control unit for recording the management information and the AV data on a recording medium;
The recording control unit compares the attribute information of the AV data decoded by the decoding unit with the management information. When the management information is different from the attribute information, the recording control unit replaces the management information with the attribute information. A recording / reproducing apparatus for recording on a medium. 2. The recording / reproducing apparatus according to claim 1, wherein the AV data is an MPEG transport stream, and the attribute information is information included in the MPEG transport stream. The management information includes at least one AV attribute information, and the attribute information includes at least one AV attribute information,
The recording control unit uses the AV attribute information included in the management information as the attribute information for AV attribute information different from the AV attribute information included in the attribute information among the plurality of AV attribute information included in the management information. The recording / reproducing apparatus according to claim 1, wherein recording is performed by replacing the AV attribute information included therein. 4. The recording / reproducing apparatus according to claim 2, wherein the AV attribute information includes at least one of a video format, a resolution, an aspect ratio, an audio format, and the number of audio channels. When the recording control unit records the AV attribute information included in the management information by replacing the AV attribute information with the AV attribute information included in the attribute information, the recording control unit also records information indicating that the AV attribute information is replaced on the recording medium. Item 4. The recording / reproducing apparatus according to Item 3. Receiving management information and AV data;
Decoding the AV data to extract attribute information;
A recording / reproducing method of comparing the attribute information with the management information, and recording the management information by replacing the management information with the attribute information when the management information is different from the attribute information.

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