JP2002118825A - Data recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data recording and reproducing device that once decodes a received MPEG transport stream, applies down-convert to a video image included in the transport stream, re-encodes the decoded stream into a transport stream with low resolution, records the stream to a recording medium, can efficiently utilize a recording area of a recording medium even when attached data included in the original stream are inserted to the re-encoded stream when reproducing the stream from the recording medium and records/reproduces the data without causing deviation in a PCR(Program Clock Reference). SOLUTION: The data recording and reproducing device employs a method where two kinds of dummy packets are prepared and the packet is inserted at recording and a method where a bit rate of a stream at recording and a bit rate of the stream at reproduction are respectively set to different values and attached data are inserted to the stream during reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a data recording / reproducing apparatus, and more particularly to a data recording / reproducing apparatus for recording digital television broadcast data on a recording medium and transmitting the recorded data to a decoding means.

[0002]

2. Description of the Related Art MPEG (Moving Picture Experts Group) 2 [I
SO / IEC13818 series] is an encoding method for compressing digital video signals and digital audio signals. MPEG2 employs a time division multiplexing method using packets. For example, when multiplexing a video signal and an audio signal using this method, the video signal and the audio signal are divided into streams of appropriate lengths called packets, and the video signal packet and the audio signal packet are appropriately divided. Switch to time division transmission. Furthermore, MPEG2 employs a multiplexing / demultiplexing method compatible with multiprogramming in order to realize transmission of a plurality of program data. For example, if this method is used, not only a video signal and an audio signal constituting one program data can be transmitted in a time division manner, but also a video signal and an audio signal constituting a plurality of programs can be transmitted in a time division manner.

[0003] Television broadcasting using MPEG2 includes SDTV (Standard Definition TV) and H.264.
There is a DTV system (High-Definition TV). SDTV
Has a resolution corresponding to the current NTSC signal, and the HDTV can transmit a video with higher definition than the current NTSC signal.

In recent years, devices for recording and reproducing such digital television broadcasts on recording media have been researched and developed. At present, the capacity of a recording medium that can be used for a product is several tens of gigabytes in consideration of the price of the recording medium.
You can only record books. Therefore, it is necessary to downconvert the data in order to extend the recording time.

On the other hand, Japanese Patent Application Laid-Open No. 9-322160 discloses that an HDTV signal is down-
There is disclosed a technique for extracting a signal as a V signal. Japanese Patent Application Laid-Open No. H11-167770 discloses a technique of decoding already recorded data, re-encoding the data at a low bit rate, and recording the data, so that the recording medium becomes available. A technique capable of increasing the area is disclosed.

However, in these conventional techniques, when downconverting digital data, accompanying data included in the data is lost. The accompanying data includes information related to the program, a program table, and the like. For example, in the case of a drama, its synopsis and character introduction can be considered. Absence of these pieces of information for programs that have been downconverted and recorded will reduce the appeal to the program.

[0007] Therefore, when a video is decoded once and re-encoded, it is necessary to insert the accompanying data included in the original data stream into the encoded data stream. However, in order to insert another data into the data stream, it is necessary to pay attention to the synchronization information included in the stream.

[0008] In order to receive and reproduce program data transmitted in a time-division manner using the transport stream system, synchronization is required between an encoder provided in the transmitting apparatus and a decoder provided in the reproducing apparatus. Need to be taken. In the transport stream method, in order to synchronize between an encoder and a decoder, information for setting and calibrating a time reference called a PCR (Program Clock Reference) is transmitted. Synchronize the encoder and the decoder based on the PCR. In order to synchronize the encoder and the decoder using the PCR, it is necessary to accurately manage the value of the PCR and the time at which the PCR arrives at the decoder. Then, the decoder determines the arrival time of the PCR and the PC.
Using the value of R, an STC (System Time Clock: System Synchronization Signal), which is a reference for decoding processing and reproduction processing, is set or calibrated in the decoder. This allows
An STC that completely matches the arrival cycle of the PCR can be created, and synchronization between the encoder provided in the transmitting device and the decoder provided in the receiving device can be established with high accuracy.

For this reason, inserting different data into the data stream changes the packet interval of the PCR information included in the data stream and changes the time at which the PCR arrives at the decoder.

On the other hand, in the technique disclosed in Japanese Patent Application Laid-Open No. H11-163817, dummy data is inserted at the time of encoding, and if there is data to be inserted, the dummy data is replaced. This solves the problem.

In the method described in Japanese Patent Application Laid-Open No. H11-163817, when encoding data, the multiplexing bit rate is set higher than the encoding bit rate, and dummy data is inserted into the surplus bit rate. I do. If there is data to be inserted, the data to be inserted is replaced with the dummy data. The prior art described in this prior application will be specifically described with reference to FIG.

FIG. 12A shows a bit stream when encoded at an original encoding rate. This bit stream is composed of video packets represented by V1 to V5 and audio packets represented by A1 to A3. FIG. 12B shows a bit stream created by a conventional encoder. D1 to D4 represent dummy packets, which are packets whose PID (packet identification number) value in the packet is 0x1fff. Compared with FIG. 12A, the amount of data to be encoded does not change from V1 to V5 and A1 to A3, but since the number of packets to be transmitted changes, the multiplex bit rate is You can see that it is higher than that. The stream obtained by inserting packets S1 to S3 into this stream is the stream represented by (c) in FIG. The position of the data insertion packet does not change compared to before the stream insertion. If there is no data to be inserted as in D4, the dummy data is left as it is.

[0013]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No.
A drawback of the method according to 163817 is that the amount of dummy data in a recording stream increases. In the case of a stream with a variable bit rate, dummy data is inserted in a portion where the data amount is coarse, and
The dummy data is replaced with a data packet and transmitted.
Therefore, when a stream is recorded at an increased multiplexing rate as in the prior art described in JP-A-11-163817, a large amount of dummy data remains in the recorded data. FIG. 13 is a diagram for explaining this.

FIG. 13A shows a bit stream encoded at the original encoding rate.
It comprises video packets represented by V1 to V3, audio packets represented by A1 to A3, and dummy packets generated at a variable bit rate represented by D1 and D2. (B) of FIG. 13 shows a bit stream created by a conventional encoder, and D3
D6 represents a dummy packet generated for inserting a packet. The packet S1
FIG. 13C shows an example in which .about.S3 is inserted. After packet insertion, the D generated by the variable bit rate
It can be seen that 1, D2 packets and D6 packets generated for inserting data remain.

Further, a disadvantage of this method is that it is impossible to distinguish between a dummy packet generated for inserting a packet and a packet generated at a variable bit rate. Since the former packet has a fixed bit rate per unit time, the bit rate of the data to be inserted can be set below the upper limit, but in the latter case, the simpler the video, the larger the dummy data amount I do. Therefore, when replacing dummy data,
It is necessary to substitute in consideration of the bit rate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object the purpose of
The transport stream is decoded once, the included video is down-converted, re-encoded into a low-resolution transport stream, recorded on a recording medium, and played back from the recording medium. Even if the accompanying data is inserted, the recording area of the recording medium can be efficiently used, and the data can be recorded / reproduced without causing a PCR shift.

[0017]

In order to achieve the above object, one typical invention of a data recording / reproducing apparatus according to the present invention is a multiplexed MPEG2-TS (Transport).
Stream; transport stream)
In a data recording / reproducing apparatus for extracting arbitrary data therein, recording the data on a recording medium, and transferring the data in the recording medium to a means for decoding, a receiving means for receiving TS data coming from outside; Separating means for separating image data, audio data, and accompanying data from TS data; image decoding means for decoding image data; audio decoding means for decoding audio data; means for down-converting the resolution of image data; Encoding means for re-encoding data and down-converted image data into digital data; insertion means for inserting the accompanying data extracted by the separating means into digital data re-encoded by the encoding means; recording medium And a recording / reproducing means.

The details of the above-described invention and other details of the data recording / reproducing apparatus according to the present invention will be apparent from the following description.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the above object is achieved by roughly using the following three techniques.

The first method is to prepare two types of dummy packets and insert the packets at the time of recording. In order to use two types of dummy packets, PIDs may be set to different values. For example, the PID of a packet generated to insert a packet is generally set to a value 0x1fff representing invalid data, and the PID of dummy data generated at a variable bit rate is
For example, it is set to something other than 0x1fff. By dividing the dummy packet into two types, only one can be removed. Therefore, by removing packets that are unnecessary for insertion from the generated dummy data, it is possible to improve the use efficiency of the recording area.

By removing the dummy packet,
In order to prevent the PCR interval from changing due to a change in the number of packets, it is necessary to maintain and restore the PCR interval.
This can be solved by inserting a pseudo packet indicating a PCR interval included in the stream into the stream. When reproducing, the PCR interval can be restored by analyzing the arrival interval in the pseudo packet included in the stream and replacing the dummy packet with dummy data so as to restore the interval.

This will be described with reference to FIG. (A) of FIG.
This represents an encoded bit stream, where C1 and C2 are dummy data generated at a variable bit rate, and D1 to D4 are generated by setting a high multiplexing bit rate to insert data. This is dummy data to be performed. First, the stream is processed to maintain the PCR interval (FIG. 9B). In the processing of the stream, a counter packet that counts the number of packets to be inserted or a pseudo packet indicating the interval of the arrived PCR is added to the stream so that the arrival time interval of the PCR included in the stream can be restored. Or a method of inserting it.
In the figure, the pseudo packet P indicating the time interval at which the PCR arrived
1, P2 is inserted.

Next, unnecessary data is eliminated by filtering (FIG. 9C). In filtering, specify the PID of the data to be left after filtering,
Check the PID of the data and check the PI
If it matches D, outputting the relevant data to delete unnecessary data, or designating the PID of the data to be deleted and outputting data that does not match the PID of the data to be deleted. Then, a method of deleting unnecessary data can be considered. In the former case, PIDs are set because dummy data generated to insert video data, audio data, and accompanying data is required. In the latter case, the PID of dummy data generated at a variable bit rate is specified.

FIG. 9D shows a stream after dummy data is replaced with data to be inserted. In this stream, the dummy data D1 to D3 are replaced with S1 to S3. S1 to S3 are associated data included in the original stream, and by recording this stream on a recording medium, the relationship between the stream and the associated data can be maintained even after down-conversion.

FIG. 9E shows a stream obtained by restoring the PCR interval at the time of reproduction. The interval of the pseudo packet indicating the arrival interval of the PCR included in the stream is analyzed, and dummy data is inserted so as to be the interval. In the figure, D'1 and D'2 packets are inserted.

According to such a method, the used capacity of the recording medium can be reduced by the amount of the removed dummy data, and
Data recording / reproducing can be performed without causing a PCR shift.

The second method is a method in which the bit rate of a stream at the time of recording and the bit rate at the time of reproduction are set to different values, and accompanying data is inserted at the time of reproduction.

First, it is assumed that an input stream is separated into video and audio data contained therein and accompanying data, and the video data and audio data are remultiplexed. The bit rate at the time of re-multiplexing at this time is defined as a recording bit rate. When recording an input stream on a recording medium, the remultiplexed data and the accompanying data are recorded as separate stream data.

For the remultiplexed data, PCR
The pseudo packet for restoring the interval is inserted, the packet that does not need to be recorded is deleted, and the packet is recorded on the recording medium. With regard to the accompanying data, indexing is performed on which data of the video / audio stream corresponds to the accompanying data, and the data is recorded on a recording medium.

At the time of reproduction, the transmission bit rate of the video / audio stream is set higher than the recording bit rate and transmitted. At this time, the dummy packet is transmitted while inserting the dummy data so that the PCR interval is restored using the pseudo packet. If there is a corresponding accompanying data, the accompanying data is inserted instead of the dummy data.

This will be described with reference to FIG. FIG. 10A shows an encoded bit stream. D1 and D2 are dummy data generated at a variable bit rate, and D3 to D6 are dummy data generated by setting a high multiplexing bit rate to insert data. First, PCR
In order to maintain the interval, the stream is processed (FIG. 10B). In the figure, pseudo packets P1 and P2 indicating the time interval at which the PCR arrived are inserted.

Next, unnecessary data is eliminated by filtering (FIG. 10 (c)). In the filtering, video data and audio data are set to be extracted, dummy data is removed, and the data is recorded on a recording medium.

At the time of reproduction, it is necessary to set the bit rate at the time of reproduction higher than the bit rate to be inputted at the time of recording and the bit rate of the accompanying data to be inserted. For example, 2 MBP is added to 8 MBPS stream data.
When inserting the accompanying data of S, the bit rate at the time of reproduction is set to 10 MBPS or more. When reading and transmitting a stream including video and audio from a recording medium, a packet for restoring the PCR interval inserted at the time of recording is detected,
When it is necessary to adjust the PCR interval, a dummy packet is transmitted. There is an accompanying packet to be inserted, and
If a dummy packet has been inserted, it is replaced with an accompanying packet instead of the dummy packet.

FIG. 10D shows this. The interval of the pseudo packet indicating the arrival interval of the PCR included in the stream is analyzed, and dummy data is inserted so as to be the interval. In the figure, D1 to D6 packets are inserted.

FIG. 10E shows a stream after dummy data is replaced with data to be inserted. In this stream, dummy data D1, D2, and D5 are represented by S1
To S3. S1 to S3 are associated data included in the original stream.

According to such a method, the used capacity of the recording medium can be reduced by the amount by which extra dummy data can be further removed, and data recording / reproducing can be performed without causing a PCR shift.

On the other hand, the accompanying data may include a PCR unique to the accompanying data. P in the stream
When analyzing the CR and adjusting the interval between streams,
It is desirable that the accompanying data does not include PCR. Therefore, when inserting into a stream, it is necessary to exclude the PCR contained in the accompanying data. this,
This will be described with reference to FIG.

FIG. 11A shows a TS packet including a PCR. The adaptation field control flag indicates whether an adaptation is included in the packet. The PCR is included in the adaptation field. When the adaptation field is included, the packet includes the adaptation field length indicating the length, a flag indicating the type of information included in the adaptation field, and the actual adaptation field. The adaptation field length indicates the byte length of the adaptation field that follows thereafter. One byte (8 bits) following the adaptation field length indicates which information is stored in the adaptation field. Among them, the PCR flag indicates that a PCR is included in the adaptation field. If the adaptation field contains a PCR,
Present in the next 6 bytes.

Without an adaptation field,
Alternatively, a packet whose PCR flag is OFF
Is not included.

To delete a PCR from a packet including the PCR, the PCR flag is turned off, the adaptation field after the PCR is shifted by 6 bytes, and finally, a stuffing byte indicating invalid data for 6 bytes is inserted. . FIG. 11B shows the TS from which the PCR has been deleted.
Represents a packet.

The third method is a method in which only an index is created without inserting the accompanying data, and the video / audio data and the accompanying data are separately supplied. This is to record the offset of the remultiplexed video / audio stream with respect to the arrived auxiliary data stream, and to transmit the corresponding auxiliary data stream when outputting the remultiplexed video / audio stream. is there.

According to this method, it is possible to avoid consumption of an extra recording area by dummy data at the time of recording, and at the time of reproduction,
There is an advantage that a complicated circuit configuration such as inserting a dummy packet is not required.

<First Embodiment> FIG. 1 is a block diagram showing a configuration of a data recording / reproducing apparatus according to a first embodiment of the present invention. In FIG. 1, 1 is a receiving unit, 2 is a separating unit, 3
Is an image decoding unit, 4 is an audio decoding unit, 5 is a down-conversion unit, 6 is an encoding unit, 7 is a PCR interval storage unit, 8 is an insertion unit, 9 is a PCR removal unit, 10 is a recording and playback unit, and 11 is a recording unit. The medium, 12 is a PCR interval restoring unit, and 13 is a decoding unit.

The receiving section 1 is means for receiving a TS (transport stream) input from the outside. The video included in the TS data is encoded as a high-resolution video.

[0045] The demultiplexing unit 2 receives the TS output from the receiving unit 1.
This is a means for separating data into video data, audio data, and accompanying data. At this time, the video data and the audio data are converted into a format for decoding by the image decoding unit 3 and the audio decoding unit 4. The accompanying data is sent to the PCR removing section 9 without format conversion.

The image decoding unit 3 is means for decoding the video data separated by the separation unit 2 and outputting a video signal. The audio decoding unit 4 decodes the audio data separated by the separation unit 2, It is means for outputting an audio signal.

The down-conversion unit 5 is means for converting the resolution of the video signal decoded by the video decoding unit 3 into a low-resolution one and outputting it. For example, a process of receiving an HDTV video signal and converting it to an SDTV signal is performed.

The encoding unit 6 encodes the video signal and the audio signal converted to the low resolution, and multiplexes them.
This is a means for outputting as one TS.

The PCR interval storage unit 7 is a means for inserting a pseudo packet for holding a PCR interval. The format of the pseudo packet to be inserted is arbitrary, but recording and reproduction processing is easier if the pseudo packet is 188 bytes like other TS packets. It is also necessary to devise a device that can immediately determine that the packet is a pseudo packet. For example, if the synchronization byte located at the head of another TS packet has a value of 0x47, the most significant bit is set to 0xc7.
This pseudo packet is inserted into the stream every time a PCR packet arrives, and has time information in which the packet including the PCR was received in the pseudo packet. During reproduction, the PCR interval is restored using this time information.

The PCR removing section 9 is a means for removing the PCR contained in the accompanying data. The processing by the PCR removing unit 9 will be described with reference to the flowchart shown in FIG. In this flowchart, it is assumed that processing is performed for each TS packet.

First, the first 6 bytes of the TS packet are read (step S1), and the adaptation field control flag and the PCR flag are checked to determine whether the TS packet contains a PCR (step S1).
2).

When it is determined that PCR is contained,
The PCR flag in the read 6-byte data is turned off and output (step S3). The next 6 bytes are PCR
And adaptation field length−7
The byte data is read and output (step S4).
Next, 6-byte stuffing bytes are output (step S5), and the remaining 183-adaptation field length data is read and output as it is (step S6).

If it is determined in step S2 that the TS packet contains no PCR, the read 6 bytes are output as they are (step S7), and the remaining data is output as it is (step S8).

By this processing, the PCR existing in the accompanying data can be removed.

The insertion unit 8 replaces the dummy data in the TS (transport stream) including the multiplexed video and audio with the accompanying data extracted by the separation unit 2. Since the accompanying data is separated in a TS format, the dummy data may be replaced with the accompanying data as it is.

The recording / reproducing unit 10 records the stream generated by the inserting unit 8 on the recording medium 11, and records the stream on the recording medium 1.
This is a means for reading the stream recorded in No. 1 and sending it to the PCR interval restoring unit 12.

The PCR interval restoring unit 12 detects a pseudo packet included in the stream, and inserts dummy data based on the time in the pseudo packet, thereby obtaining a PCR.
Means for restoring the interval. The transmission rate is set to be equal to or higher than the sum of the bit rate of the stream generated by the encoding unit 6 and the bit rate of the accompanying data. However, since the PCR interval is restored and transmitted, the number of valid packets arriving at the decoding unit 13 per unit time does not change.

The decoding unit 13 receives the stream transmitted by the PCR interval restoring unit 12 and synchronizes video and audio using PCRs contained in the stream,
This is a means for separating video data, audio data, and accompanying data, decoding and displaying video data, and decoding and reproducing audio data. The accompanying data is output in a manner appropriate to the content.

Next, the transition of the stream in each means in the apparatus of this embodiment will be described with reference to FIG.

First, the stream input to the receiving unit 1 is represented by (a) in FIG. V1 to V5 are video data,
A1 to A3 represent audio data, S1 to S3 represent accompanying data, and D1 represents dummy data TS packets generated at a variable bit rate. The inverted triangle mark in the figure indicates that the packet contains a PCR. That is, PCR is included in each TS packet of V1, V4, and S1.

This stream is supplied to the separation unit 2,
It is separated into video data, audio data, and accompanying data. Among the streams separated by the separation unit 2, the accompanying data is
It is extracted as shown in FIG. At this stage, S1
Since the packet contains a PCR, the PCR removal unit 9 removes the PCR contained in the accompanying data (FIG. 6C).

On the other hand, the stream re-encoded and re-multiplexed by the encoding unit 6 is represented by (d) in FIG. This stream is composed of video data represented by V′1 to V′5, A ′
To A′3. this house,
PCR is included in the V'1 packet and the V'4 packet. The bit rate is lower than that of the original stream because the video is converted into a lower resolution video by the down conversion.

Next, the PCR interval storage unit 7
Pseudo packets P1 and P used to restore the interval of R
2 is inserted ((e) in FIG. 6), and P
The accompanying data from which the CR has been removed is inserted into the stream ((f) in FIG. 6). The stream is recorded on the recording medium 11 by the recording / reproducing unit 10 in this format.

When the data is reproduced, the data is read out by the recording / reproducing unit 10 in the format shown in FIG. 6F and the stream is read by the PCR interval restoring unit 12 while inserting dummy data for adjusting the PCR interval. (G in FIG. 6). The bit rate at this time is set higher than that of the stream generated by the encoding unit 6. D1 to D4 in the figure are dummy data inserted to adjust the PCR interval.

<Second Embodiment> FIG. 2 is a block diagram showing a configuration of a data recording / reproducing apparatus according to a second embodiment of the present invention.

In FIG. 2, 1 is a receiving section, 2a is a separating section, 3 is an image decoding section, 4 is an audio decoding section, 5 is a down-converting section, 6a is an encoding section, 7 is a PCR interval storage section, and 8 is a PCR interval storing section.
Denotes an insertion unit, 9 denotes a PCR removal unit, 10 denotes a recording / reproducing unit, 11
Is a recording medium, 12 is a PCR interval restoring unit, 13 is a decoding unit,
14a and 14b are filter units.

The receiving unit 1, the image decoding unit 3, the audio decoding unit 4, the down-converting unit 5, the PCR interval storing unit 7, the inserting unit 8, the PCR removing unit 9, the recording and reproducing unit 10, the recording medium 11, the PCR medium Since the interval restoring unit 12 and the decoding unit 13 are the same as those in the first embodiment, the description is omitted. The separating unit 2a converts the TS (transport stream) output from the receiving unit 1 into video data and audio data. , And other data. Among them, the video data is output to the image decoding unit 3 and the audio data is output to the audio decoding unit 4.

The encoder 6a generates two types of dummy packets. One is dummy data generated at a variable bit rate, and the other is generated by setting the multiplexing bit rate higher than the sum of the video encoding bit rate and the audio encoding bit rate. This is dummy data to be performed. These are distinguished by a PID or the like included in the packet.

The filter section 14a is a filter for removing dummy data generated at a variable bit rate from the dummy data generated by the encoding section 6a. PIDs corresponding to video data, music data, and dummy data generated by multiplexing are set, and filtering is performed by outputting a TS packet having the set PID.

The filter section 14b is a filter for extracting accompanying data from a stream input from the outside. Filtering is performed by setting a PID corresponding to the accompanying data and outputting a TS packet having the set PID.

Next, the transition of the stream in each means in the apparatus of this embodiment will be described with reference to FIG.

First, the stream input to the receiving unit 1 is represented by (a) in FIG. V1 to V5 are video data,
A1 to A3 represent audio data, S1 to S3 represent accompanying data, and D1 represents dummy data TS packets generated at a variable bit rate. The inverted triangle mark in the figure indicates that the packet contains a PCR. That is, PCR is included in each TS packet of V1, V4, and S1. This stream is supplied to the separation unit 2 and the filter unit 14b, respectively.

FIG. 7B shows the stream after filtering by the filter unit 14b. Filter unit 1
In 4b, a PID corresponding to the accompanying data is set, and a TS packet having the set PID is output. Therefore, it becomes a stream from which the accompanying data is extracted. At this stage, since the S1 packet contains the PCR, the P1
The PCR is removed from the stream by the CR removing unit 9 (FIG. 7 (c)).

On the other hand, video data,
The stream separated into audio data and other data is remultiplexed by the image decoding unit 3, the audio decoding unit 4, the down-converting unit 5, and the encoding unit 6a. The stream after re-multiplexing is represented by (d) in FIG. V '~
V'3 is video data, A'1 to A'3 are audio data,
C′1 and C′2 represent dummy data generated at a variable bit rate, and D′ 1 to D′ 4 represent dummy data generated at a multiplexed bit rate. Of these, V '
One packet and V'3 packet include a PCR.
The bit rate is set lower than that of the original stream because the video has been converted into a lower resolution video by down conversion. It should be noted that PID values 0x1fff representing null packets are assigned to C′1, C ′ in D′ 1 to D′ 4.
2, a different PID value is set.

The pseudo-packets P1 and P2 used to restore the PCR interval are inserted by the PCR interval storage unit 7 ((e) in FIG. 7). Then, the filter unit 14a
To extract video data, audio data, and dummy data generated at a multiplex bit rate. FIG. 7F shows this. Dummy data C ′ generated at a variable bit rate from the stream
It can be seen that 1, C'2 has been deleted.

A stream obtained by replacing the dummy data of this stream with the accompanying data is represented by (g) in FIG. Dummy data D'1 to D'3 are replaced with S1 to S3, respectively. The stream is recorded on the recording medium 11 by the recording / reproducing unit 10 in this format.

In the case of reproduction, the data is read out by the recording / reproducing section 10 in the format shown in FIG. 7 (g), and the stream is read by the PCR interval restoring section 12 while inserting dummy data for adjusting the PCR interval. The data is transmitted at a higher bit rate than the combination of the data and the accompanying data (FIG. 7 (h)).

<Third Embodiment> FIG. 3 is a block diagram showing a configuration of a data recording / reproducing apparatus according to a third embodiment of the present invention.

In FIG. 3, 1 is a receiving unit, 2a is a separating unit, 3 is an image decoding unit, 4 is an audio decoding unit, 5 is a down-converting unit, 6 is an encoding unit, 7 is a PCR interval storage unit, and 9 is A PCR removing section, 10a and 10b are recording / reproducing sections, 11 is a recording medium, 12a is a PCR interval restoring section, 13 is a decoding section,
4a and 14b are filter units, and 15 is a tagging unit.

Among them, the receiving unit 1, the image decoding unit 3, the audio decoding unit 4, the down-converting unit 5, the encoding unit 6, the PCR
The interval storage unit 7, the PCR removal unit 9, the recording medium 11, and the decoding unit 13 are the same as in the first embodiment,
a, and the filter sections 14a and 14b are the same as those in the second embodiment, and thus the description thereof is omitted.

The recording / reproducing section 10a is a means for recording the video / audio stream extracted by the filter section 14a on the recording medium 11, reading the recorded stream, and sending it to the PCR interval restoring section 12a.

The recording / reproducing unit 10b is a means for recording the accompanying data stream extracted by the filter unit 14b on the recording medium 11, reading the recorded stream, and sending it to the PCR interval restoring unit 12. In order to synchronize with the video / audio stream recorded by the recording / reproducing unit 10a, the offset position of the recorded video / audio stream is input from the tagging unit 15 and recorded on the recording medium 11 together with the accompanying data stream. When the stream is reproduced, the offset position of the video / audio stream being reproduced is input from the tagging unit 15, and the corresponding accompanying data is transmitted to the PCR interval restoring unit 12a.

The tagging section 15 has two recording / reproducing sections 10
This is means for synchronizing the stream recorded and reproduced by the recording and reproducing unit 10b with the stream a. The offset position of the stream recorded / reproduced by the recording / reproducing unit 10a is extracted and sent to the recording / reproducing unit 10b.

The PCR interval restoring unit 12a detects a pseudo packet included in the stream, and inserts dummy data based on the time in the pseudo packet to obtain the PC data.
This is a means for restoring the interval of R. The transmission rate is determined by the bit rate of the stream generated by the encoding unit 6 and
It is set to be equal to or greater than the total value of the bit rate of the accompanying data. However, since the PCR interval is restored and transmitted, the number of valid packets arriving at the decoding unit 13 per unit time does not change. When the accompanying data is input from the recording / reproducing unit 10b, the input accompanying data is inserted instead of the dummy data.

Next, the transition of the stream in each means in the apparatus of the present embodiment will be described with reference to FIG.

First, the stream input to the receiving unit 1 is represented by (a) in FIG. V1 to V5 are video data,
A1 to A3 represent audio data, S1 to S3 represent accompanying data, and D1 represents dummy data TS packets generated at a variable bit rate. The inverted triangle mark in the figure indicates that the packet contains a PCR. That is, PCR is included in each TS packet of V1, V4, and S1. This stream is supplied to the separation unit 2a and the filter unit 14b, respectively.

FIG. 8B shows the stream after filtering by the filter unit 14b. Filter unit 1
In 4b, a PID corresponding to the accompanying data is set, and a TS packet having the set PID is output. Therefore, it becomes a stream from which the accompanying data is extracted. At this stage, since the S1 packet contains the PCR, the P1
The PCR is removed from the stream by the CR removing unit 9 ((c) in FIG. 8).

On the other hand, video data,
The stream separated into the audio data and other data is remultiplexed by the image decoding unit 3, the audio decoding unit 4, the down-converting unit 5, and the encoding unit 6. The stream after re-multiplexing is represented by (d) in FIG. V'1
V'3 is video data, A'1 to A'3 are audio data,
D'1 to D'6 represent dummy data generated at a variable bit rate. Of these, V'1 packet and V '
PCR is included in three packets. The bit rate is set lower than that of the original stream because the video has been converted into a lower resolution video by down conversion. Note that D′ 1 to D′ 6 include P representing a null packet.
It is assumed that an ID value 0x1fff is set.

Next, the PCR interval storage unit 7
Pseudo packets P1 and P used to restore the interval of R
2 is inserted (FIG. 8E). Thereafter, video data and audio data are extracted by the filter unit 14a.
This is shown in FIG. 8 (f). It can be seen that the dummy data D'1 to D'6 have been deleted from the stream.

The recording / reproducing unit 10a transmits this stream to
The information is recorded on the recording medium 11. On the other hand, the stream of accompanying data processed by the PCR removing unit 9 is
0b is recorded on the recording medium 11. At this time,
The offset position of the video / audio stream recorded by the recording / reproducing unit 10a is extracted by the tagging unit 15, and is simultaneously recorded on the recording medium 11.

For reproduction, the video / audio stream is read out by the recording / reproducing unit 10a in the format shown in FIG. The recording / reproducing unit 10b finds out the associated data stream from the offset position of the video / audio stream being reproduced, and reproduces it.

Next, the PCR interval restoring unit 12a
Data is transmitted while inserting dummy data for adjusting the PCR interval. At this time, if there is accompanying data to be inserted, the accompanying data is inserted instead of the dummy data. This is shown in FIG. 8 (h).

The stream shown in (g) of FIG. 8 is for describing a fourth embodiment to be described later. In this embodiment, FIG. 8 is referred to except for (g) of FIG. I want to.

<Fourth Embodiment> FIG. 4 is a block diagram showing a configuration of a data recording / reproducing apparatus according to a fourth embodiment of the present invention.

In FIG. 4, 1 is a receiving section, 2a is a separating section, 3 is an image decoding section, 4 is an audio decoding section, 5 is a down-converting section, 6 is an encoding section, 7 is a PCR interval storage section, and 9 is a PCR interval storing section. A PCR removing section, 10a and 10c are recording / reproducing sections, 11 is a recording medium, 12 is a PCR interval restoring section, 13a is a decoding section,
4a and 14b are filter units, 15 is a tagging unit, and 16 is a memory unit.

Among them, the receiving unit 1, the image decoding unit 3, the audio decoding unit 4, the down-converting unit 5, the encoding unit 6, the PCR
Interval storage unit 7, PCR removal unit 9, recording medium 11, PCR
The interval restoration unit 12 is the same as in the first embodiment, and includes a separation unit 2a, a filter unit 14a, and a filter unit 14b.
Is the same as that of the second embodiment.
0a and the tagging unit 15 are the same as those of the third embodiment, and thus the description thereof is omitted.

The recording / reproducing unit 10c records the associated data stream extracted from the filter unit 14b on the recording medium 11, reads the recorded stream, and reads out the recorded stream.
It is a means for performing a process of supplying to the unit. Recording / reproducing unit 10a
In order to synchronize with the video / audio stream recorded by the above, the offset position of the recorded video / audio stream is input from the tagging unit 15 and recorded on the recording medium 11 together with the accompanying data stream. When playing a stream,
The offset position of the video / audio stream being reproduced is input from the tagging unit 15, and the corresponding accompanying data is supplied to the memory unit 16.

[0098] The memory unit 16 is means for storing the accompanying data supplied by the recording / reproducing unit 10c.
The data in the memory unit 16 is referred to by the decoding unit 13a.

The decoding unit 13a receives the stream transmitted by the PCR interval restoring unit 12, and separates the data into video data and audio data while synchronizing video and audio using PCR included in the stream. It is a means for decoding and displaying data, and for decoding and reproducing audio data. The accompanying data is obtained by referring to the memory unit 16 and is output in a manner appropriate to the contents.

Next, the transition of the stream in each means in the apparatus of this embodiment will be described with reference to FIG.

First, the stream input to the receiving unit 1 is represented by (a) in FIG. V1 to V5 are video data,
A1 to A3 represent audio data, S1 to S3 represent accompanying data, and D1 represents dummy data TS packets generated at a variable bit rate. The inverted triangle mark in the figure indicates that the packet contains a PCR. That is, PCR is included in each TS packet of V1, V4, and S1. This stream is supplied to the separation unit 2a and the filter unit 14b.

FIG. 8B shows the stream after filtering by the filter unit 14b. Filter unit 1
In 4b, a PID corresponding to the accompanying data is set, and a TS packet having the set PID is output. Therefore, it becomes a stream from which the accompanying data is extracted. At this stage, since the S1 packet contains the PCR, the P1
The PCR is removed from the stream by the CR removing unit 9 ((c) in FIG. 8).

On the other hand, video data,
The stream separated into the audio data and other data is remultiplexed by the image decoding unit 3, the audio decoding unit 4, the down-converting unit 5, and the encoding unit 6. The stream after re-multiplexing is represented by (d) in FIG. V'1
V'3 is video data, A'1 to A'3 are audio data,
D'1 to D'6 represent dummy data generated at a variable bit rate. Of these, V'1 packet and V '
PCR is included in three packets. The bit rate is set lower than that of the original stream because the video has been converted into a lower resolution video by down conversion. Note that D′ 1 to D′ 6 include P representing a null packet.
It is assumed that an ID value 0x1fff is set.

Next, the PC is stored in the PCR interval
Pseudo packets P1 and P used to restore the interval of R
2 is inserted (FIG. 8E). Thereafter, video data and audio data are extracted by the filter unit 14a.
This is shown in FIG. 8 (f). It can be seen that the dummy data D'1 to D'6 have been deleted from the stream.

The recording / reproducing unit 10a converts this stream into
The information is recorded on the recording medium 11. On the other hand, the stream of accompanying data processed by the PCR removing unit 9 is
0c is recorded on the recording medium 11. At this time, the offset position of the video / audio stream recorded by the recording / reproducing unit 10a is extracted from the tagging unit 15, and is simultaneously recorded on the recording medium 11.

For reproduction, the video / audio stream is read by the recording / reproducing unit 10a in the format shown in FIG. Next, the PCR interval restoring unit 12
The data is transmitted while inserting the dummy data for adjusting the interval of. This is shown in FIG. 8 (g). This stream is supplied to the decoding unit 13a.

On the other hand, the recording / reproducing unit 10 c determines a corresponding accompanying data stream from the offset position of the video / audio stream being reproduced, and supplies it to the memory unit 16. The data in the memory unit 16 is referred to by the decoding unit 13a, and the decoding unit 13a outputs the accompanying data obtained from the memory unit 16 in a manner appropriate to the content.

The stream shown in FIG. 8 (h) is for explaining the third embodiment, and in this embodiment, please refer to FIG. 8 except for FIG. 8 (h). .

[0109]

The operation and effect of the invention according to each claim of the present application are as follows.

According to the first and second aspects of the present invention, a high-resolution image is down-converted, re-encoded and recorded, and additional data such as program information included in the original stream is inserted into the re-encoded stream. Therefore, the use efficiency of the recording area can be improved without losing the accompanying data.

According to the third aspect of the present invention, since the accompanying data is inserted at the time of reproduction, there is no need for a dummy data area prepared for replacing the accompanying data at the time of recording. Therefore, unnecessary dummy data can be removed.

According to the fourth aspect of the present invention, the video / audio stream and the accompanying data stream are separately supplied to the decoding device, so that it is not necessary to replace the dummy data with the accompanying data at the time of reproduction. It can be easily configured.

In the invention according to claim 5, by including two types of dummy data in the encoded data, one of them can be used as dummy data for inserting dummy data.

In the invention according to claim 6, by removing one of the two types of dummy data, the use efficiency of the recording area can be improved.

In the invention according to claim 7, even when the data to be inserted includes PCR, the interval between PCRs can be restored.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a data recording / reproducing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a data recording / reproducing device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a data recording / reproducing device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a data recording / reproducing device according to a fourth embodiment of the present invention.

FIG. 5 is a flowchart showing a processing flow of a PCR removing unit used in the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing stream transitions according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a transition of a stream according to the second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing stream transitions according to the third and fourth embodiments of the present invention.

FIG. 9 is an explanatory diagram showing a processing operation such as packet insertion using two types of dummy packets in the present invention.

FIG. 10 is an explanatory diagram showing processing operations such as packet insertion performed during reproduction in the present invention.

FIG. 11 is an explanatory diagram of a method of deleting a PCR from a TS packet.

FIG. 12 is an explanatory diagram showing a technique for inserting a dummy packet according to a conventional technique.

FIG. 13 is an explanatory diagram showing a technique for inserting a dummy packet according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving part 2, 2a Separation part 3 Image decoding part 4 Audio decoding part 5 Down conversion part 6, 6a Encoding part 7 PCR interval preservation part 8 Insertion part 9 PCR removal group 10, 10a, 10b, 10c Recording / reproducing part 11 Recording Medium 12 PCR interval restoration unit 13, 13a Decoding unit 14a, 14b Filter unit 15 Tagging unit 16 Memory unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) H04N 7/08 7/081 7/24 F term (reference) 5C053 FA17 FA20 GB06 GB11 GB38 HA21 JA03 JA16 JA21 KA04 KA21 KA24 LA06 5C059 KK33 KK39 MA00 MC26 RB06 RC02 RC03 RC04 RC07 RC31 SS02 UA02 UA05 5C063 AA01 AA06 AB03 AB07 AC01 AC05 BA03 CA11 CA12 CA23 DA13 5D044 AB07 BC01 BC04 CC04 DE12 DE39 DE49 DE52 EF05 FG18 FG21 G

Claims (7)

[Claims] 1. A multiplexed MPEG2-TS (transport stream) data is inputted, arbitrary data is extracted, recorded on a recording medium, and the data in the recording medium is transferred to a decoding means. Receiving means for receiving TS data arriving from the outside, separating means for separating image data, audio data and accompanying data from the received TS data, image decoding means for decoding image data, Audio decoding means for decoding the audio data, means for down-converting the resolution of the image data, encoding means for encoding the audio data and the down-converted image data into digital data again, extracted by the separating means Insertion means for inserting the accompanying data into the digital data re-encoded by the encoding means When the data recording and reproducing apparatus characterized by the recording and reproducing means to a recording medium, comprising a. 2. A data recording / reproducing apparatus for inputting multiplexed MPEG2-TS data, extracting arbitrary data from the multiplexed MPEG2-TS data, recording the data on a recording medium, and transferring the data in the recording medium to decoding means. , Receiving means for receiving TS data coming from outside, separating means for separating image data and audio data from the received TS data, image decoding means for decoding image data, and audio decoding means for decoding audio data Means for down-converting the resolution of image data; encoding means for encoding the audio data and the down-converted image data into digital data again; and accompanying data for extracting accompanying data from the TS data received by the receiving means. Filtering means; and digital data obtained by re-encoding the associated data by the encoding means. And inserting means for inserting the data, the data recording and reproducing apparatus characterized by the recording and reproducing means to a recording medium, comprising a. 3. A data recording / reproducing apparatus which inputs multiplexed MPEG2-TS data, extracts arbitrary data from the multiplexed MPEG-2 TS data, records the data on a recording medium, and transfers the data in the recording medium to decoding means. , Receiving means for receiving TS data coming from outside, separating means for separating image data and audio data from the received TS data, image decoding means for decoding image data, and audio decoding means for decoding audio data Means for down-converting the resolution of image data; encoding means for encoding the audio data and the down-converted image data into digital data again; and accompanying data for extracting accompanying data from the TS data received by the receiving means. Filtering means for recording and reproducing the re-encoded digital data on a recording medium; Data comprising: recording / reproducing means; second recording / reproducing means for recording and reproducing accompanying data on a recording medium; and insertion means for inserting the accompanying data into digital data re-encoded during reproduction. Recording and playback device. 4. A data recording / reproducing apparatus for receiving multiplexed MPEG2-TS data, extracting arbitrary data from the multiplexed MPEG-2 TS data, recording the data on a recording medium, and transferring the data in the recording medium to decoding means. , Receiving means for receiving TS data coming from outside, separating means for separating image data and audio data from the received TS data, image decoding means for decoding image data, and audio decoding means for decoding audio data Means for down-converting the resolution of image data; encoding means for encoding the audio data and the down-converted image data into digital data again; and accompanying data for extracting accompanying data from the TS data received by the receiving means. Filtering means for recording and reproducing the re-encoded digital data on a recording medium; Recording / reproducing means; second recording / reproducing means for recording and reproducing the accompanying data on a recording medium; memory means for storing the accompanying data read from the recording medium by the second recording / reproducing means; And a decoding means for decoding and outputting the digital data reproduced by the recording and reproducing means, and for acquiring and outputting the associated data stored in the memory means. 5. The data recording / reproducing apparatus according to claim 1, wherein the encoding unit includes at least two types of dummy data having different PIDs in the encoded data. 6. The data according to claim 5, further comprising a dummy data filtering unit for excluding one of two types of dummy data from the data extracted from the re-encoded digital data. Recording and playback device. 7. The data recording / reproducing apparatus according to claim 1, further comprising: a synchronization information removing unit that removes synchronization information from the accompanying data.