JPH0787443A - Device for generating/reproducing/synchronizing and managing compressed signal - Google Patents

Abstract

PURPOSE:To record data efficiently, to facilitate data management, to attain special reproduction of a program and high speed search and to accurately obtain synchronization with a video and audio signal. CONSTITUTION:A video image grouping means 103 groups video data for each prescribed video frame number, a video compression means 106 applies compression coding to the data in the unit of groups, an audio grouping means 102 groups audio data for each group unit, an audio compression means 105 applies compression coding to each group, an expansion data grouping means 104 groups expansion data in the unit of groups, an expansion data compression means 107 applies compression coding to each group and a formatter 108 connects plural groups of compressed data to obtain a data unit. A separate means 121 separates the compressed data, an audio decoder 122 decodes coded audio data, a video decoder 123 decodes the coded video data, an expansion data decoder 124 decodes coded expanded data, and a synthesis means synthesizes decoded video data and decoded expanded data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a writable / readable magnetic disk, an optical disk, or a CD-ROM as a recording medium, and produces / reproduces a compressed signal effective when the signal to be handled is an encoded compressed signal. / It relates to a synchronization and management device.

[0002]

2. Description of the Related Art Although a recording medium such as a magnetic disk or an optical disk has a smaller recordable data capacity than a magnetic tape, it is possible to access the data at a high speed. Can be done easily. Furthermore, it is considered that recent advances in high-efficiency compression encoding technology for image data have made it possible to store a large number of programs and the use of the recording / reproducing apparatus using the disc as a recording medium will increase. As such a moving image compression recording method, for example, ISO-11172
(MPEG) and the like.

A conventional disk system will be described below. The format of the disc usually includes a data area and a management area indicating what kind of information is recorded in each part of the data area (FIG. 12 (A)).

The data area is made up of clusters, and the size of one cluster is fixed and fixed in the range of 1 sector to 64 sectors. The size of one sector is 128 bytes to 8 bytes.
It is fixed within the range of 192 bytes.

The management area is provided on the inner circumference side of the disc, and the directory table (see FIG. 12) is provided on the innermost circumference.
(B)), and a file allocation table (FIG. 12C) on the outer periphery thereof. The directory table stores the program name and the first cluster. When the name of the program to be reproduced is searched in the directory table, the leading cluster is known. When the start cluster is known, the start cluster number is searched in the file allocation table. When this top cluster number is searched, the second cluster number that follows is recorded there, so the next (2
The second) cluster number is known. Two
Once the second cluster number is found, the second cluster number is searched next, and the third is recorded in the file allocation table.
In this way, the cluster numbers to be reproduced are known one after another, and when the last cluster number is reached, the end information is paired.

Therefore, when the disc is reproduced, the desired program name is searched for in the directory table of the management area, and the leading cluster number is recognized.
Next, in the file allocation table (FAT), the cluster numbers to be reproduced are read one after another.

Here, the capacity of the management area can be expressed as follows. Directory capacity = number of recorded programs x (program name + first cluster) [bytes] FAT capacity = number of programs x (1 program size / cluster size) x 1 cluster representation size on FAT [bytes] By the way, many programs are written to disk In order to record, it is necessary to secure a large data area and a small management area. However, if many programs are recorded, the capacity of the management area becomes large accordingly. Therefore, from the above relationship, in order to reduce the capacity of the management area, the cluster size may be increased. However, if the cluster size is increased, one cluster length is fixed (a fixed number of sectors). Therefore, if the end of one program ends with a small number of sectors from the beginning of a certain cluster, the data area There is waste.

It is conceivable that such waste often occurs particularly in a system employing the moving picture compression technique described above. In the moving image compression technique, the physical signal length is undefined because the interframe compression technique using the data of the frames temporally adjacent to each other and the variable length coding technique are used. Therefore, if the length of one cluster is fixed, there is a high possibility that the data area will be wasted. Further, when reproducing a signal using this moving image compression technique, there is no problem in that it is sequentially reproduced from the beginning, but it is difficult to realize functions such as special reproduction and high-speed search.

[0009]

As described above, in the conventional disc recording / reproducing system, when the signal encoded by the moving picture compression technique or the signal subjected to the variable length is recorded, the data area is likely to be wasted. There's a problem. Further, it is difficult to realize functions such as special reproduction of a signal recorded by using the moving picture compression technique and high speed search. Further, in the case of a video signal, an audio signal is involved, but in the case of a signal using a moving image compression technique, it is necessary to synchronize the video and audio.

Therefore, the present invention enables efficient data recording, easy data management, special reproduction of programs, high-speed search, and easy synchronization with video and audio. It is an object to provide an apparatus for creating / reproducing / synchronizing and managing a compressed signal that can be obtained.

[0011]

As a first means, the present invention is grouped and grouped so that video data can be separated at least for a fixed number of playback times or a fixed number of video frames corresponding to the number of playback times. A video grouping and video compression means for compressing and coding the video data in units of groups, and a voice grouping and audio compression means for grouping and coding the corresponding audio data for each group of the video data. , The encoded video data from the video compression unit is connected by a plurality of groups, the encoded audio data from the audio compression unit is connected by a plurality of groups, and these groups are combined and output as a data unit, or a recording system or And a formatter for outputting to the transmission system.

As a second means of the present invention, storage means for managing the data of the program recorded on the recording medium is formed as a data allocation table, and each unit of this table is on the disk. A portion for storing each information of the track number, the zone number belonging to the track, the sector number on the track, and the link pointer of the data unit designated to be reproduced next is provided.

Further, as a third means of the present invention, on the encoder side, a coded video is obtained by coding a fixed number of video frames, which is a fixed time length of an original video, and collecting a plurality of the coded ones. Video grouping and compression means for making data into one video packet, and audio group for making coded audio data corresponding to the packetized coded video data by a plurality of audio frames into one audio packet And an audio sample number and an audio sample number in the audio packet relating to the original audio corresponding to the beginning of a specific video frame in the encoded video data that is one video packet Additional data creating means for data, the additional data,
The audio packet and the video packet are combined to form one data unit, and a formatter for sequentially creating such a data unit is provided. On the decoder side, the encoded video data and the encoded video data are encoded for each data unit. Output that decodes audio data and additional data, and operates the output time of the decoded specific video frame when the audio frame number included in the encoded audio data and the audio frame number included in the additional data match. And timing setting means.

[0014]

According to the first means, the video frames are grouped by a certain number of sheets, coded and compressed within each group, and the compressed video data of a plurality of groups are included in the data unit. No Therefore, each data unit can be handled independently and the video signal can be decoded. Therefore, even if efficient disk recording is performed by compression, reproduction and decoding can be performed for each data unit. Second
According to the means, since it has the track number, zone number, and sector number, even if the data length of the data unit recorded as described above is not fixed but variable, the result can be easily managed. As a result, the data recording efficiency of the disc can be improved. Further, according to the third means, the synchronization between the audio and the video can be accurately obtained, and the synchronized state can be constantly monitored.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First, the moving picture compression format in the present invention will be described. When encoding video data, first, a plurality of groups of pictures (GOP) are packetized together, and audio data (about 1.0 seconds) corresponding to this packet and extension data are encoded and compressed. It becomes a data unit by being added to the video data. The GOP is fixed in the same program, and the time code for voice synchronization is arranged in the first subcode in the extended data of the data unit.

FIG. 1 shows encoded coded data (see FIG.
FIG. 1A schematically shows an example of FIG. 1A and an output image (FIG. 1B) obtained by decoding the same. In the figure, I is the intra-frame encoded video data, P is the forward predictive encoded image data, and B is the bidirectional predictive encoded image data. In this mode, I, P, B, P , B are repeated to perform encoding. Therefore, the encoded data length of each frame is different. According to such a format, if only I is reproduced, it is 6 times speed, and if I and P are reproduced, it is 2 times.
You can get double speed images. The actual speed factor is limited to the data read speed from the disc. This format is suitable for high-speed transfer rate, large recording capacity, and quasi-random access. In this example, 6 frames are treated as 1 GOP as shown in FIG. And 5 GOP becomes one packet. This packet corresponds to a reproduction time of 1.0 second. However, since the actual recording signal length on the disc is encoded by the moving image compression technique, it differs depending on the packet.

Therefore, one packet corresponds to 30 frames (=
It is 5 GOP × 6 frames / GOP), and the audio data is 48 KByte (= 4 ch × 1) for each 30 frames.
2 KByte / s). If the number of channels used simultaneously is 2, the minimum required memory capacity is 24 KBy
te is enough.

The main data for each data unit to be recorded on the disc and each information rate are as follows. Extended data = 128 Kbit / s = 16 KByte / s Audio data = 384 Kbit / s = 48 KByte / s Video data = 4096 Kbit / s = 512 KByte
The / s extension data includes a subcode and sub-picture data. The sub-picture data can be used for subtitle information used in movies. Further, the subcode is individual management information in the data unit, and also includes audio and video synchronization information. The sub-picture data is updated on a GOP basis including the corresponding main picture, and the synchronization and synchronization correction of the picture and the audio are also performed on a GOP basis.

With respect to the subtitle information, a plurality of channels may be prepared as sub-image data so that two types of sub-images can be selectively output, such as an English scenario in a Western movie and a Japanese script. Sub-image data allocation rate is 64K
If it is bit / s, the recording time number of one packet is 1.
If it is 0 second, the buffer capacity for holding the sub-picture data is about 64 Kbit. However, the buffer memory capacity required when the sub-picture has two channels may be 32 kbit.

In encoding each of the above-mentioned video, audio, and extension data, all of them are completed in a data unit and completely independent of other data units. Next, a management area described later is secured on the disk. Reading is performed for each data unit based on the information in the management area. Since each data unit is processed independently,
Easy to edit and access for each data unit.

The relationship between the data area and the management associated with it will be described. In the actual arrangement, byte alignment processing is performed for each GOP, and secura alignment processing is always performed for each data unit to facilitate the division of data units. The reduction rate of the actual recording capacity due to sector alignment is as follows. Data unit configuration is screen display frame rate 30 sheets / sec, GOP
When the number of constituent pictures is 6 (frames) and the number of GOPs in one data unit is 5 GOPs, sector alignment occurs for each data corresponding to approximately 1.0 seconds, and therefore a disk of 120 minutes recording records 7200 sectors. The capacity decreases. When the total recording capacity of the disc is 346752 sectors, the capacity decrease rate is 0.2% (however, 1 KB
/ Sector).

At the time of reproduction, the video starts from the decoding of the first frame (I picture) of the GOP. The audio starts from the decoding of the audio frame specified by the audiovisual synchronization. When the decoding of the designated audio frame and the decoding of the video GOP first frame are both completed, the video and the designated audio sample are simultaneously output.

As voice data, about 1.0 second of encoded voice data is added in the data unit. However, in encoding audio, one block is composed of a fixed number of samples, the adjacent block ends are slightly folded, and then encoded in units of the number of samples, and a header is added to this to create one encoded audio frame.

The voice frame length is equal to or less than 2048 sample lengths of the original voice, and when converted into the original voice time, 24 ms to 36
ms. The amount of encoded data of a voice frame is 288.
Byte to 576 bytes. A frame ID is attached to the header of every audio frame for each audio channel. The frame ID is 24 bits, 4 bits representing an audio channel and 20 bits representing an audio frame number. The encoded voice data for about 1.0 seconds usually has a length of several tens of voice frames, although it depends on the number of samples in one block and the sampling frequency. The video-audio synchronization added to the subcode is the frame number of the coded audio to which the decoded audio sample to be output should be output at the timing when the output of the head frame of the corresponding GOP starts, and the audio sample number within that frame. Is specified. The time code is 32 bits, 20 bits represent the audio frame number, and the remaining 12 bits specify the audio sample number. As a result, the maximum error in audio / video synchronization in the entire system coincides with 1/2 of the audio sampling period, and the maximum video / audio synchronization error is about 16 μs when fs = 32 KHz.

2 to 3 show other examples of moving picture compression formats. Next, a system for managing a plurality of programs encoded and recorded as described above will be described. First, a management area is provided on the disc, and a management table is recorded therein.

FIG. 4A shows a management table position in the management area and a zone arrangement example of the data area. The management table includes the innermost volume identity field (VID), the outer program information field (PIF), and the outer data unit allocation table (DA).
There is T). The VID is written from the first byte of the management table area and uses 256 bytes to indicate the specification information of the entire disc. For example, the information is a general recording disc, a reproduction-only disc, or the like (FIG. 5A).

In the program information field (PIF), specification information of each program is recorded. For example, 16 bytes are used for each program.
FIG. 5B shows an example of the 16-byte contents of PIF.

ATMB is the absolute time of the current program start point in the volume. (In the case of the time code search, first, each ATMB data is checked in the program reproduction order to detect the program number in which the desired time code exists. Next, each DAT (described later) in the corresponding program is checked to check the program time (PTMB : Later) and AT
(A search can be performed by the procedure of comparing the one to which MB is added with a desired time code value and detecting the DAT to which the corresponding time code belongs). With the absolute start time method, the user can know the absolute start time from the desired program number. Therefore, by searching the ATMB corresponding to the absolute start time, the specific PI
F data can be detected.

PINF indicates a program attribute.
As the program attribute, the attribute is described for each program, and the copy prohibition flag (CPNH), program type (PTYPE), write attribute (PWR)
T), the number of GOPs that make up the data unit (SGDU)
There is. If CPNH is “1”, copy is prohibited, if it is “0”, copy is permitted. PTYPE uses 3 bits, and home video, movie, music, karaoke, computer graphic, interactive, game, computer data, program, etc. Indicates the type of. PW
If RT is "1", it indicates that writing is possible. SGDU indicates any one of mode 1, mode 2 and mode 3 described above using 3 bits.

In addition, the PIF also stores parameters as shown in FIG. 5 (B). AINF is the identification of the audio encoding system, VINF is the identification of the video encoding system,
ATRT is a picture attribute, that is, aspect ratio, PA
Information for identifying the system such as L and NTSC, HRES
Is the screen horizontal resolution, and VRES is the screen vertical resolution.

PNTB is a start pointer,
D where the data unit at the program start point is saved
It is a pointer value indicating the AT address (data unit number). DAT will be described next, but this DAT
By recognizing the address (data unit number), the position of the head sector of the program in the data area can be recognized.

PGML indicates a program number to be reproduced following the current program or if the related program exists. That is, the reproduction order of the programs does not always match the order of the program numbers. If the current program is the final program, there is no link destination and PGML has all bits "1".

FIG. 5C shows the structure of DAT. In this table, there are zone number (NZON), sector number (NSCT), track number (NTRC), program time (PTMB), and link pointer (PNTL) as parameters.

NZON is the zone number to which the recording sector at the head of the data unit belongs. The zone numbers are consecutively assigned from the reference position for each track. That is, as shown in the data area of FIG.
There is 1, and the numbers are sequentially added from 0 from this position. One track consists of many zones. NSCT is
When the zone is determined, the sector number in the zone is shown. The sector number is not a serial number related to other tracks or zones, but is a number completed within that zone. NTRC indicates the track number in which the zone and sector number (the head of the data unit) are present.
Further, PTMB is a flag indicating temporal position information of the video data (I picture) at the head of the data unit, the content of which is relative elapsed time (seconds) from the program start point.
Is. This temporal position information is used when the time code search described above is performed. Further, this temporal position information is taken in by the reproducing device side and used as start reference data when performing program time, absolute time, remaining amount display and the like.

The next PNTL is a flag for indicating the next DAT unit number which is consecutive in time with the current DAT unit number. The unit corresponds to the data unit number, and if there is no link destination such as the program end point, all bits are "1" (= 0xFFFF). Valid values for the link pointer are 0x0000 to 0xFFFF
Is.

Returning to FIG. 4, description will be made. FIG. 4B shows D
The example of AT is shown. DAT unit number is 0 to N
It is continuous at max. The first DAT unit number is determined by referring to PNTB of PIF. DA now
If the T unit number is 1, the next link pointer is 0. The link pointer for the DAT unit number 0 is Nmax-1. And DAT unit number Nmax-
The link pointer for 1 is 2. Where the above DAT
Looking at the zone number, track number, and sector number in accordance with the transition of the unit number, sector 4 of zone 1 of track 4, sector 2 of zone 0 of track 7, and track 10
It is possible to obtain the reproduction order information of the zone 3 and the sector 30 of.

FIG. 6A shows an example of address arrangement in the management table shown in FIG. 5A and an example of address arrangement in DAT. In addition, FIG. 6B is another example of arrangement of addresses in the management table, and is an example in which an unused area is set between VID, PIF, and DAT. In this case, VID
There is an address offset when searching PIF data from the VID data, but this offset information is
MPU for drive control, which is included in some data of
Is recognized when executing the address management program.

Next, a trial calculation of the capacity of the above-mentioned management table will be made. The capacity for holding the management table depends on the number of programs and the number of data units recorded on the disc. When the total number of programs is 256 and the number of data units is 7200 (1 second / unit, 2 hours equivalent),
The total data of the management table is 256+ (16 × 256)
+ (8 × 7200) = 61952 bytes.

That is, in a system in which one data unit corresponds to about 1 second, the management data for 2 hours can be handled by allocating the 63 KB memory to the data management table, and this capacity is practically sufficient. Is.

The physical position of the start sector of the management table is normally ZONE = 0, TRACK = 0, SECTOR.
However, it may be redundantly written in different areas as a spare from the viewpoint of data protection. Since the management table is often referred to, the access operation becomes slow if the data on the disk is read every time. Therefore, the management table may be first mapped to the work RAM of the drive control MPU. However, if the table capacity is too large, the memory cost may not match the product cost.If the configuration of the table itself is not appropriate, a large amount of calculation may be required each time to convert to the desired parameter value. It is preferable to set an appropriate method according to the product cost and the table capacity.

FIG. 7 shows an encoder according to the present invention,
The block configuration of the decoder is shown. Input terminal 100
The original signal is supplied to. This original signal is separated by the separating means 10.
1, the audio data, the video data, the extended data such as subtitles, the synchronizing signal, etc. are separated. The audio data is input to the audio grouping unit 102, the video data is input to the video grouping unit 103, and the extension data is input to the extension data grouping unit 104. The sync signal is
It is input to the first system control means 110. The first system control means 110 controls the video grouping means 103 so as to group every 6 frames of video data when mode 1 is designated, and groups the audio data of this time unit. The audio grouping means 102 is controlled so as to perform the above, and the extended data grouping means 104 is controlled so as to group the extended data for the corresponding frames. Grouped video data is
It is input to the video compression means 106 and encoded and compressed as described in FIG. The grouped voice data is also compressed by the voice compression unit 105, and the grouped extension data is also compressed by the extension data compression unit 107. The outputs of the compression means 105106 and 107 are input to the formatter 108. Here, in the case of mode 1,
Five GOPs (encoded video data) are collected, and corresponding encoded audio data, encoded extension data, and subcode (additional data) are added to the data unit as shown in FIG. Is output as. When encoding is performed by each compression means, the generated code amount is controlled so that the data amount is an integral multiple of the sector capacity.

The signal output from the formatter 108 is recorded on a recording medium or sent to a transmission system. The signal taken in from the recording medium or the transmission system is separated by the separating means 121.
At, the data is processed for each data unit, and the encoded audio data, the encoded video data, the encoded extension data, and the subcode are extracted from the data unit. The encoded audio data is decoded by the audio decoder 122, the encoded video data is decoded by the video decoder 123, and the encoded extension data is decoded by the extension data decoder 124. The decoded extension data is combined with the decoded video data by the combining unit 125. This gives the original audio signal,
The video signal will be reproduced. The information contained in the subcode is input to the second system control means 126,
It is used as a timing signal generation reference for each block, video sound synchronization, or mode setting information.

In this system, a device for synchronizing audio and video is devised. Next, the data unit will be described again. As described above, for the video data, one packet corresponds to 30 frames (= 5 GOP × 6).
30 frames / GOP for audio data is 48 KByt (= 4 ch × 12 KByt).
e / s) (Mode 1). When the number of channels used simultaneously is 2, the minimum required memory capacity is 2.
4 KByt is enough.

FIG. 7 shows encoded video data, encoded audio data, and additional data included in the data unit. The audio is encoded by setting a certain number of samples as one block and performing encoding in units of the number of samples and adding a header to form one frame. The header includes a frame ID for frame identification.

Next, the subcode includes additional information. The additional information includes data indicating the correspondence between the coded video data and the coded audio data. That is,
The encoded video data of FIG. 7A has a video frame number, and the encoded audio data also has an audio frame number (FIG. 7B). Therefore, it is assumed that the first frame of each GOP (data subjected to intra-frame compression processing: this is a specific video) is special 1, special 2, ..., And the audio frame numbers of the encoded audio data are special respectively. 1 for k-1
When the special 2 corresponds to k + 6 and the special 5 corresponds to k + n, this related information is inserted into the additional data (FIG. 7C). In addition, special data 1
Sample numbers corresponding to special 2 ... are also added. As for the sample number, in the example of the figure, the audio frame number of the encoded audio data corresponding to the special encoded video data is k−1, and the frame sample number is 6
It means that it is 15. Further, it means that the audio frame number of the encoded audio data corresponding to the special 2 encoded video data is k + 6, and the frame sample number is 12.

Next, the means for creating the above-mentioned additional data will be described. FIG. 8 shows additional data creating means.
The original video signal is supplied to the terminal 201. This original video signal is quantized by the quantizing means 202 and input to the frame memory 203. The original video signal from the frame memory 203 is input to the video encoding unit 204 in frame units and output as encoded video data in 1 frame units. This coded video data has a format as shown in FIG. 1, for example, in a formatter provided in the subsequent stage. A video frame pulse is supplied to the input terminal 205, and is used as a write / read timing signal for the frame memory 203 and a timing signal for the video encoding means 204. A program start pulse is input to the input terminal 206. The 1/6 frequency divider 207 is cleared by this program start pulse, the video frame pulse is counted, and the pulse of the specific video frame period shown in FIG. 7, that is, the specific video frame pulse is created.

On the other hand, an audio sampling pulse is input to the input terminal 208, and an original audio signal is input to the input terminal 209. The original audio signal is sampled and quantized by the sampling / quantization means 210, and the output is
It is input to the voice encoding means 211 and encoded. As a result, encoded voice data is obtained, and the frame number is added to the header at the subsequent stage.

The voice sampling pulse of the input terminal 208 is 1 / N, where N is the number of samples in one voice frame.
It is input to the frequency divider 212, divided into 1 / N, and output as a voice frame pulse. The voice frame pulse is
It is input to the voice encoding means 211. As a result, the voice encoding unit 211 performs voice encoding on a frame-by-frame basis. The audio frame pulse is input to the audio sampling pulse counter 213 as a clock. The audio sampling pulse counter 213 is cleared by the audio frame pulse. Therefore, the output data represents the number of audio samples in one audio frame. The number of voice samples is input to the register 215. The audio frame number is also input to the register 215. The audio frame number is created by the audio frame pulse counter 214. That is, in the audio frame pulse counter 214, the audio frame number can be created by clearing each program start pulse and counting the audio frame pulses. The audio frame number and the number of audio samples are input to the register 215, which are latched by the specific video frame pulse and output. The number of audio samples is cleared by the audio frame pulse and increases sequentially, but in the middle of that, it is latched by the specific video frame pulse.
It is the audio sample number corresponding to the specific video.

The additional data obtained from the register 215 is used by the formatter in the subsequent stage to create the data unit as shown in FIG. FIG. 9 shows a synchronization processing means for reproducing the above-mentioned additional data and synchronizing audio and video.

At the time of reproduction, encoded video data, encoded audio data, and additional data are reproduced for each data unit. The output time of the decoded video data and audio data is specified by the additional data. The encoded audio data read from the recording medium is input terminal 3 for each data unit.
01 to the audio buffer 302, and the encoded video data is input to the video buffer 3 via the input terminal 311.
12 is input. Further, the additional data is input to the input terminal 321 and taken into the register 322.

The encoded voice data is also input to the frame number extraction means 305. The encoded audio data output from the audio buffer 302 is input to the audio decoding unit 303, decoded, and input to the audio block buffer 304. The encoded video data output from the video buffer 312 is input to the video decoding means 313, decoded, and input to the video frame buffer 314. The video data is decoded in units of one video frame. The audio data is decoded in units of one audio frame, and the decoded sample data for one audio sample block is stored in the audio block buffer 304.

The audio frame number extracted by the frame number extracting means 305 is input to the comparing means 323. The comparison unit 323 compares the frame number extracted from the additional data with the audio frame number extracted by the header of the encoded audio data. When the comparison unit 323 obtains the coincidence pulse (YES), the gate unit 324 extracts the sample number included in the additional data, and this sample number becomes the preset input of the address counter 325.

As a result, the audio block buffer 304
The audio sample data position to be read of the decoded audio data in is determined. Also, the coincidence pulse starts the audio sampling pulse generating means 326 and the video frame pulse generating means 327, and the audio data is output in synchronization with the corresponding sample number whose relation to the video data is designated by the additional data. Become.

In the comparing means 323, the mismatch pulse (N
If O) is obtained, the additional data in the shift register 332 is shifted, and the process proceeds until the next synchronization information is read. For example, if a disagreement pulse is obtained in the processing that should be the characteristic 1 = k−1 in FIG. 7, the next synchronization information characteristic 2 = k
The shift register 322 is shifted to +6, and the frame number k + 6 included in the additional data is set in the comparison unit 323. Here, it is determined whether or not the frame number included in the encoded audio data string matches, and this process is performed until the frame numbers match. If the frame numbers match with this processing (for example, if matching is obtained with special 2 = k + 6), then the video data in the video decoding means 313 and the frame buffer 314 are processed until they become special 2 decoded video data. It This synchronization adjustment is performed by the adjusting means 328. Therefore, in this case, the sound is output in synchronization from the time of the second specific video output.

Until the coincidence pulse is obtained from the comparing means 323, it is not necessary to output the video and audio, or only the video may be output. After the coincidence pulse is obtained, the audio and video in the video group are synchronized with each other, and thereafter the operation of the comparison means may be stopped. Then, the comparison means may be operated periodically according to the position of the specific video signal.

In the operation of the adjusting means 323 when the non-coincidence pulse is obtained, if the structure of the audio frame is large, the process proceeds to the second and fourth specific video frames. Even if the frame is large 204
Since the sample length is about 8, synchronization is established by the third specific video frame.

In the above description, when the output time of the specific video frame and the designated audio sample are synchronized, the data output time of the video frame buffer and the audio block buffer is controlled. A means for adjusting the storage time of the data buffer memory (not shown) or the storage time of the encoded data buffer memory (not shown) may be further introduced.

FIG. 10 shows another embodiment of the video / audio correcting means. Coded video data is input to the input terminal 401, and the coded video data is decoded in the video decoding and frame buffer 402. Input terminal 40
3 is supplied with the internal clock of the reproducing apparatus, and is divided into 1 / M by the 1 / M frequency divider 404 and output as a video frame pulse. This video frame pulse is supplied as a timing signal to the previous video decoding and frame buffer 402 and is also input to the 1/6 frequency divider 405.
The frequency is divided into 1/6 and output as a specific video frame pulse synchronized with the specific video signal shown in FIG.

The encoded audio data is input to the audio decoding means 407 via the input terminal 406 and decoded, and this decoded audio data is input to the decoded audio block buffer 408. An internal clock is input to the input terminal 411, and the internal clock is 1 / N by the 1 / N frequency divider 412.
And is output as an audio sampling pulse.
The voice sampling pulse is input to the voice frame pulse creating means 413 and also to the decoded voice sample address counter 414. The audio frame pulse creating means 413 creates an audio frame pulse corresponding to the audio frame period and gives it to the decoded audio sample address counter 414 and the audio decoding means 407 as a timing signal.

Decoded voice sample address counter 414
Is reset with a voice frame pulse and counts the voice sampling pulse so that its output will represent a voice sample number. The audio sample number is used as a read address of the decoded audio block buffer 408 and is also input to the register 415. The register 415 latches the audio sample number at the timing of the specific video frame pulse, and inputs this to the comparison means 416. The comparison means 416 compares the audio sample number included in the additional data given from the input terminal 417. If a coincidence pulse is obtained here, it means that the video data and the audio data are synchronized in a predetermined relationship.

However, if a mismatch pulse is obtained, it means that the audio frame specified by the additional data does not correspond to the specific video signal. Therefore, synchronization adjustment is necessary, but in this system, comparison means 416
To 1 / N frequency divider 412, a frequency division number adjustment signal is given. Thereby, the phase of the audio sampling pulse and the audio frame pulse phase are controlled. In practice, in the comparison means 416, when the difference between the two audio sample numbers to be compared is a certain value or more, the frequency division number of the 1 / N frequency divider 412 is increased or decreased by about 1 or 2, for example. After this processing, if the difference between the two audio sample numbers compared by the comparison means 416 falls within the range, the adjustment state is maintained.

Although the frequency division number of the 1 / N frequency divider 412 is adjusted in the above description, the frequency division number of the 1 / M frequency divider 404 may be adjusted, or both may be adjusted. Good. By doing so, even if there is a slight difference between the internal clock frequencies on the encoding side and the decoding side, it is possible to continue to correct the synchronization between the video and audio at the stage where a large synchronization deviation does not occur.

[0063]

As described above, according to the present invention,
Efficient data recording is possible, data management is easy, special reproduction of programs and high-speed search are possible, and furthermore, synchronization between video and audio can be accurately and easily obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a signal compression format according to an embodiment of the present invention.

FIG. 2 is a diagram showing a signal compression format according to another embodiment of the present invention.

FIG. 3 is a diagram showing a signal compression format of still another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a disk data array and a management table shown for explaining data management in an embodiment of the present invention.

FIG. 5 is a detailed explanatory diagram of a control chart table.

FIG. 6 is an explanatory diagram showing an example of a control chart table.

FIG. 7 is a diagram showing a configuration example of an entire system according to an embodiment of the present invention.

FIG. 8 is a diagram showing details of a data unit in the embodiment of the present invention.

9 is a diagram showing an example of an encoder of the processing system of the data unit of FIG.

10 is a diagram showing an example of a decoder of the processing system of the data unit of FIG.

11 is a diagram showing another example of the decoder of the processing system of the data unit of FIG.

FIG. 12 is an explanatory diagram shown for explaining a conventional disk management system.

[Explanation of symbols]

101 ... Separation means, 102 ... Voice grouping means, 10
3 ... video grouping means, 104 ... extended data grouping means, 105 ... audio compression means, 106 ... video compression means, 107 ... extended data compression means, 108 ... formatter, 121 ... separation means, 122 ... audio decoder, 123
... video decoder, 124 ... extended data decoder, 125
... synthesizing means, 202 ... quantizing means, 203 ... frame memory, 204 ... video coding means, 207 ... 1/6 frequency divider, 210 ... sampling quantizing means, 211 ... audio coding means, 211 ... 1 / N Frequency divider, 214 ... Voice frame pulse counter, 213 ... Voice sample pulse counter, 215 ... Register, 302 ... Buffer, 303 ... Voice decoding means, 304 ... Voice block address, 305 ...
Frame number extraction means, 312 ... Buffer, 313 ... Video decoding means, 314 ... Video frame buffer, 322 ...
Registers, 323 ... Comparison means, 324 ... Gate means, 3
25 ... Address counter, 326 ... Audio sampling pulse generating means, 327 ... Video frame pulse generating means.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04N 5/781 Z 7734-5C 5/92 5/93 7/24 8420-5L G06F 15/66 330 A 7734-5C H04N 5/92 Z 7734-5C 5/93 Z 7/13 Z

Claims (10)

[Claims] 1. A video grouping method in which video data is grouped so that video data can be separated for each fixed number of playback times or a certain number of video frames corresponding to the number of playback times, and the grouped video data is compression-encoded in group units. Video compression means; audio grouping and audio compression means for grouping corresponding audio data for each group unit of the video data and compression-encoding in group units; and encoding video data from the video compression means. A formatter for connecting packets into a plurality of groups, converting the encoded audio data from the audio compression means into a plurality of groups, and outputting at least these packets as a data unit, and outputting to a recording system or a transmission system. An apparatus for producing a compressed signal, comprising: 2. An extension data grouping and compression unit for grouping extension data to be inserted into the video data for each video group unit and compressing each group unit to create encoded extension data. 2. The compressed signal generating apparatus according to claim 1, wherein the formatter includes the encoded extension data in the data unit. 3. The data unit is arranged in the order of a subcode, a packet of encoded extension data, a packet of encoded audio data, and a packet of encoded video data in the time direction, and the subcode includes the packet of the encoded audio data. The synchronization information indicating the correspondence between the group and the group of the coded video data is included, and the head data of each group of the coded extension data, the coded audio data, and the coded video data is the time before grouping. 3. The compressed signal generating apparatus according to claim 2, wherein the data is the first data. 4. Coded video data in which video data is grouped so as to be separable by a certain number of playback times or a certain number of video frames corresponding to the number of playback times, and the grouped video data is compression-coded in group units. For each group unit of the video data, corresponding audio data is grouped and compression-encoded in group units, and extension data to be inserted into the video data is grouped for each video group unit. A voice unit that receives compressed data of a plurality of groups each of which is connected to the encoded extension data, separates the encoded voice data from the data unit to obtain decoded voice data, and a code from the data unit. A video decoder that separates the decoded video data and decodes it to obtain decoded video data; An extension data decoder that separates the encoded extension data from a data unit and decodes the encoded extension data to obtain decoded extension data, and combines the decoded video data obtained from the video decoder with the decoded extension data obtained from the extension data decoder. A reproducing apparatus for a compressed signal, comprising: a synthesizing unit. 5. A storage means for managing data of a program recorded on a recording medium is formed as a data allocation table, in which the track number on the disk, the zone number to which the track belongs,
And a sector number on the track, and a section for storing each piece of information of a link pointer of a data unit designated to be reproduced next as a set. 6. The program data is grouped so that the video data can be separated at a fixed number of playback times or a fixed number of video frames corresponding to the number of playback times, and the grouped video data is compressed in units of groups. Encoded video data, encoded audio data obtained by compressing and encoding corresponding audio data for each group unit of the video data, and extension data to be inserted into the video data for each video group unit. 6. The compressed signal management apparatus according to claim 5, wherein a data unit obtained by connecting a plurality of groups of encoded expanded data that has been grouped and compressed is recorded with each data unit number attached. . 7. An encoder side encodes a fixed number of video frames, which is a fixed time length of an original video, and sets a plurality of the coded video data as one video packet. A video grouping and compression unit, a voice compression grouping unit that configures the encoded audio data corresponding to the packetized encoded video data into a plurality of audio frames into one audio packet, and one video A voice frame number in the voice packet relating to the original voice corresponding to the start timing of a specific video frame in the encoded video data which is a packet, and a voice sample number in the voice frame are created and added as additional data. By combining the data creating means and the additional data, the audio packet, and the video packet into one data unit, A data formatter that sequentially creates different data units, and on the decoder side, decodes the coded video data, the coded audio data, and the additional data for each data unit, and decodes the specific video frame. A compressed signal having an output timing setting means for operating the head output time when the voice frame number included in the encoded voice data and the voice frame number included in the additional data match. Synchronizer. 8. The specific video frame pulse output means for outputting the specific video frame pulse at a position corresponding to the beginning of the video frame pulse of the original video, which is cleared by a program start pulse, in the additional data creating means. First dividing means for dividing the voice sampling pulse for sampling the original voice to obtain the voice frame period, and clearing with the voice frame pulse from the first dividing means, A voice sampling pulse counter for counting sampling pulses, a voice frame pulse counter for counting the voice frame pulses cleared by the program start pulse, a count value from the voice sampling pulse counter, a voice sample number, the voice frame pulse counter Voice count value from As frame number, the synchronization device of the compressed signal according to claim 7, characterized by including a register for latching and outputting the particular video frame pulse. 9. The output timing setting means extracts the voice frame number included in the encoded voice data, compares the voice frame number with the voice frame number included in the additional data string, and responds to a match pulse when they match. Then, the audio sample number included in the additional data is preset in the address counter, and the reading of the audio data from the audio block buffer storing the decoded audio data is started based on the address obtained from the address counter. 9. The compressed signal synchronizing apparatus according to claim 8, further comprising means for starting reading of the decoded video data in which the decoded video signal is stored. 10. The encoder side encodes a fixed number of video frames, which is a fixed time length of an original video, and sets a plurality of the coded video data as one video packet. A video grouping and compression unit, a voice compression grouping unit that configures the encoded audio data corresponding to the packetized encoded video data into a plurality of audio frames into one audio packet, and one video Additional data creating means for creating an audio frame number and an audio sample number in the audio packet relating to the original audio corresponding to a specific video frame in the encoded video data, which is a packet, as additional data, Such data units are created one after another by combining data, voice packets, and video packets into one data unit. The decoder side has a video formatter for decoding the coded video data for each data unit to obtain decoded video data, and the decoded video data from the video decoding means for each frame. A frame buffer for storing, a voice decoding means for decoding the encoded voice data for each data unit to obtain decoded voice data, a voice block buffer for storing the decoded voice data from the voice decoding means in block units, First frequency dividing means for generating a video frame pulse for obtaining the output timing of the frame buffer from an internal clock; second frequency dividing means for dividing an internal clock to generate an audio sampling pulse and an audio frame pulse. Counting the audio sampling pulses reset by the audio frame pulse More in the count value, and the decoded audio samples address counter for creating a read address of the audio block buffer, the output address of the decoded sample address counter,
When the register for latching at the position of the specific video frame pulse obtained by dividing the video frame pulse is compared with the audio sample number included in the additional data and the address obtained from the register, and when the difference is a predetermined value or more, And a means for performing synchronization adjustment of the video frame pulse by the frequency division control of the first frequency division means or the audio sampling pulse by the frequency division control of the second frequency division means. And a compressed signal synchronization device.