JPH07220405A - Information signal recording method and reproducing method as well as information signal recording device and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the reduction in recording capacity of a recording medium according to dummy data which are added to match to unit block time on recording/reproduction when recording or reproducing video data of variable length. CONSTITUTION:The field termination of video data of variable length is detected by an end detection circuit 16 and the amount of dummy data added between this end and the top of the next field is counted by a dummy data counter 18. When the count value exceeds the recording/reproduction unit blocks, a pause control signal is sent to a buffer control circuit 36E and writing from a buffer 37E to a hard disk device 39 is stopped by one block. The dummy data should be eliminated by memory operation etc. before recording from the buffer 37E to the hard disk device 39.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information signal recording method and a reproducing method, an information signal recording apparatus and a reproducing apparatus,
In particular, the present invention relates to a method and apparatus for recording / reproducing variable-length data such as compression-coded video data to / from a disc-shaped recording medium.

[0002]

2. Description of the Related Art In general, when an analog video signal is digitized, the amount of data becomes enormous and it is difficult or costly to record or communicate as it is. I often do it. In particular, since the data amount of a video signal is much larger than that of an audio signal, it is important to use an encoding method with a high compression rate. In recent years, high-efficiency video signal data compression encoding requires a code per unit time. An encoding method in which the amount of the encoded output data changes, for example, a so-called variable length encoding method has been widely adopted.

FIG. 6 is a diagram for explaining an example of compression of video signal data, and A shows an analog video signal. In general, since a video signal constitutes one image in one frame or one field, the analog video signal in FIG. 6A is compressed / expanded in the unit of one frame or one field in the time axis direction. ing. When compressing motion information using the correlation between frames or fields in video compression, the compression / expansion process spans several frames or fields, but the input to the compression circuit and the expansion circuit The output is an image of the original frame or field unit.

In the example of FIG. 6, in-field compression is performed in which the time unit T _V of video signal compression is 1 field, that is, 1/60 (seconds), and the sampling frequency F
s is 13.5 MHz. In this example, the composite video signal is divided into a luminance (Y) signal and a color (C) signal, and each is sampled at Fs = 13.5 MHz and 8
Quantization is performed bit by bit to obtain the signal of B in FIG. 6, that is, digital video data. This is 13.5M
The data of Hz × 8 bits is 216 Mbps (megabits / second) for two channels of Y and C, and is 3.6 Mbits per field, that is, the number of words of 8 bits per word is 450 K words per field. .

This is compressed field by field and a maximum of 12
In the case of variable-length data of Mbps, a maximum of 200 K bits per field, that is, a maximum of 25 K words per word of 8 bits. This is because the video data of 3.6 Mbits = 450 K words per field is compressed to 1/18 or less, and as shown in C of FIG.
The data will be compressed within K words.

In the case of such compression encoding, the compression rate is almost constant on average over a plurality of fields, but often varies in a unit of one field time.

By the way, in recent years, in the case of transmitting, that is, recording / reproducing or transmitting / receiving an information signal including video information and audio information, in recent years, in consideration of application to a so-called multimedia system,
It is becoming more common to digitize each information, code it, and synthesize it.

FIG. 7 is a diagram for explaining an example of data compression of an audio signal, and A shows an analog audio signal. Since the audio signal is a continuous signal unlike the video signal, the compression unit can be arbitrarily selected. In this case, it is conceivable that the video signal is compressed in the unit time of compression of the video signal, that is, in the unit of time that is the same as the field or frame time or a time of an integer ratio. The unit time of these compressions does not match.

As a compression method developed for a commercially available recording / reproducing small audio disc, a sampling frequency of 44.1 kHz and stereo PCM data of left and right channels are respectively digitized into 16 bits and 512. An example of a method of compressing each sample to 212 bytes will be described.

The analog audio signal shown in FIG. 7A is 51 when the sampling frequency is 44.1 kHz.
The time T _A corresponding to two samples, that is, T _A = 512 / (44.1 × 10 ³ ) (sec) ≈11.6 (msec) is compression-encoded as a unit. That is, 512 samples of 1 sample 16 bits shown in B of FIG. 7 or 512 × 2 words when 1 word is set to 8 bits are compression-encoded to fix 212 × 2 words shown in C of FIG. Long data. The unit time of this fixed length data, for example, the data amount per second, that is, the data rate R _A is R _A = 212 × 2 × 8 / T _A (bit / sec = bps). The unit time T of such audio signal compression
_A has nothing to do with the unit time T _V of compression of the video signal, and does not have a simple integer ratio relationship.

[0011]

When the variable length video data and the fixed length audio data as described above are combined and transmitted, or when only the variable length data is transmitted, the data of the line given to the encoder. The rate is
The maximum length of variable-length video data should be set as a guide. Therefore, as shown in FIG. 8, there is a difference between the encoder's peak data rate a and the encoder's average data rate b and the transmission rate c required for the line. The difference is the dummy data d. The processing that is embedded in is required.

By the way, Japanese Laid-Open Patent Publication No. 5-2834 discloses that variable length data of the first type and fixed length data of the second type are received, and the addition value of each data amount becomes a predetermined value. Discloses a technique of forming one data block from these data and information indicating the amount of each data, and storing a series of data blocks in a recording medium. In this technique, when the sum of the amount of the first type data and the amount of the second type data at the end of reception falls short of a predetermined value,
This shortage of desired data is added to form one data block. This desired data is, for example, all 0 data, and is dummy data for filling in the insufficient data amount.

When such dummy data is recorded or reproduced on a recording medium, the amount of the dummy data is wasted, which causes a decrease in use efficiency of the recording medium or a decrease in recording capacity, which is not preferable.

The present invention has been made in view of such circumstances, and when only variable length data is combined or variable length data and fixed length data are combined and recorded / reproduced on / from a recording medium, fixed recording is performed. The recording efficiency and recording capacity are prevented from lowering without recording the dummy data added for rate conversion on the recording medium, and the processing such as separation of each data can be performed without problems during playback, and the circuit configuration is simple. Another object of the present invention is to provide an information signal recording method and a reproducing method, and an information signal recording apparatus and a reproducing apparatus.

[0015]

The information signal recording method according to the present invention has a variable length in which the amount of data per unit time obtained by compression-encoding the first input data at every first fixed time varies. In an information signal recording method for recording data on a recording medium by dividing data into blocks at constant block times, dummy data is added to the variable length data to form fixed rate variable length data having a constant data rate. The dummy data is recorded on the recording medium in units of blocks, and when the data amount of the dummy data exceeds the one block, the recording on the recording medium is stopped for the one block.

The information signal reproducing method according to the present invention is
An information signal reproducing method for reproducing a recording medium recorded by the above information signal recording method, wherein the removed dummy data is added to variable length data read from the recording medium to form a fixed rate. It is decompressed and decoded and reproduced at regular intervals of 1.

Further, the information signal recording apparatus according to the present invention is
An information signal for recording variable length data, obtained by compressing and encoding the first input data at every first constant time, in which the data amount per unit time changes, into blocks at a constant block time and recording it on a recording medium. In the recording device, means for adding dummy data to the variable-length data to form fixed-rate variable-length data having a constant data rate, and means for removing the dummy data and recording in blocks on the recording medium And means for controlling the stop of recording on the recording medium by the unit of one block when the data amount of the dummy data exceeds the one block.

Further, the information signal reproducing apparatus according to the present invention is a reproducing apparatus for reproducing the recording medium recorded by the above-mentioned information signal recording method, and the variable length data read from the recording medium is removed as described above. It has means for adding dummy data to make it a fixed rate, and means for decompressing and decoding the fixed-rate variable length data at the first fixed time intervals.

Here, it is preferable that information indicating the amount of the deleted dummy data is recorded on the recording medium together with the variable length data. Further, fixed length data having a constant amount of data per unit time obtained by compressing and encoding the second input data at every second constant time and the variable length data are combined, and at each block time. It is preferable that the data is divided into blocks and recorded on the recording medium.

As concrete data formats, variable length data obtained by compressing and encoding the first input data at a first fixed time interval and changing the data amount per unit time, and second input data. Is combined with fixed length data having a constant amount of data per unit time obtained by compressing and encoding the second constant time, and dummy data is added to the variable length data to obtain a constant data rate. An example is one in which fixed rate variable length data is formed and a predetermined amount of the fixed length data and another predetermined amount of the fixed rate variable length data are arranged in one block as a unit of transmission.

Header data including the data amount of the dummy data may be added in the block. Also,
The fixed length data may have an integer ratio relationship between the time of one block, which is a unit of the transmission, and the second constant time. Furthermore, examples of the variable length data include video data, and examples of the fixed length data include audio data.

[0022]

Since the dummy data is removed, the use efficiency of the recording medium or the apparent recording capacity can be improved.

Further, even if the dummy data is removed, since the data amount information of the dummy data is recorded on the recording medium together with the variable length data, the dummy data is added at the time of reproduction to generate the fixed rate variable length data. It can be restored, and the decoding processing in the first constant time unit can be effectively performed.

Further, even when the variable length data and the fixed length data are combined and recorded and reproduced, the respective data can be easily separated.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, it is assumed that the recording / reproducing of the data is performed on a recording / reproducing device in a so-called AV server that transmits / receives audio / video data to / from a plurality of terminal devices.

FIG. 1 shows an example of the configuration on the encoder side on the recording side when the above-mentioned video and audio signals are combined, divided into blocks, and recorded / reproduced on / from a recording medium.

In FIG. 1, an analog video signal is supplied to the input terminal 11 and an analog audio signal is supplied to the input terminal 21. The analog video signal from the input terminal 11 is an analog / digital (A /
D) It is sent to the converter 13 and converted into a digital video signal. The digital video signal from the A / D converter 13 is sent to the video encoder 14 and compression-coded into variable-length data whose data amount per unit time varies.
This variable length data is obtained as data having a variable data amount equal to or less than a fixed maximum data amount for each unit time T _V of compression encoding. Examples of the video encoder 14 include so-called JPEG (Joint Photographic CodingExperts Group).
An encoder that realizes the encoding method defined in (1) can be used.

The variable length data from the video encoder 14 is sent to the end detection circuit 16 via the video buffer 15, and the video buffer 15 and the end detection circuit 16 have a dummy data addition function. Cage,
As will be described later, dummy data is added to fix the data rate. This is fixed-rate data by adding dummy data to variable-length data until the maximum data amount is reached every unit time of compression encoding.
The output from the end detection circuit 16 is sent to a data line or an I / O data bus 31 for transmitting data to and from a recording medium such as a hard disk in the AV server.

On the other hand, the analog audio signal from the input terminal 21 is sent to the A / D converter 23 and converted into a digital audio signal, and then the audio encoder 24.
And compressed and encoded into fixed-length audio data. As the audio encoder 24, it is possible to use, for example, a recordable compact audio optical disk device, a compression encoding encoder used in a digital compact audio tape recorder, or the like.

The fixed length data from the audio encoder 24 is passed through the audio buffer 25, the end detection circuit 16 and the data line in the server or I.
/ O data bus 31. Header data from a header generation circuit 26, which will be described later, is also sent to the I / O data bus 31 via the end detection circuit 16.

Data line or I / O data bus 31
Each data sent to the buffer 37E is sent to the buffer 37E via the multiplexer 34E and recorded on the disk-shaped recording medium recording / reproducing device, for example, the hard disk device 39. These buffer 37E and hard disk device 3
The operation of 9 is controlled by the buffer control circuit 36E.
Here, the AV server of this embodiment assumes a multi-channel configuration in which a plurality of hard disk devices 39 are used in parallel to achieve high throughput and a plurality of encoder circuit units 10 are also used. Further, the entire AV server system is configured to include a plurality of channel decoders as described later. Multiplexer 34E
The buffer control circuit 36E and the buffer 37E may be shared with the multiplexer 34D, the buffer control circuit 36D, and the buffer 37D on the decoding side of FIG.

In the block counter 17 of the encoder circuit section 10, the word clock CLK from the multiplexer 34E, the start of the video field from the end detection circuit 16, ie, the detection signal of SOI: start of image and the end of the video signal EOI: end of image. The detection signal is supplied. This block counter 17
Is preset with the number of words in one transmission block as shown in FIGS. 2 and 3, for example, a value K when one block is K words, and the end-of-block signal EOB is dummyed every time this value K is counted. It is sent to the counter 18 and the operation of starting the counting of the block word number K again is performed. Further, the difference between the count value at the time of detecting the EOI at the end of the video field and the count value at the time of detecting the SOI at the start of the next field is set to the dummy size D.
It is taken out as S and sent to the dummy counter 18 and the header generation circuit 26. Note that the multiplexer 34E
The word clock CLK from is also sent to the end detection circuit 16 and the dummy counter 18.

The block counter 17 determines the video area and the audio area in accordance with the block format shown in FIG. 2A by counting the number of words from the beginning of the block, and outputs the enable signal EN to the video buffer 15 and the video buffer 15 for each area. Send to audio buffer 25.
As shown in A of FIG. 2, an area of audio data A of a predetermined word from the start position and a video area of another predetermined word including video data V and dummy data D are set in each block. In addition, the block counter 17
In order to add a header to the end of one field of the video data V, the header generation circuit 26 is controlled to send an enable signal EN to generate header data. The header data includes at least information such as the size of the dummy data, that is, the dummy size DS which is the number of words, and the number of words up to the next header. This header is
It is a field header arranged between the end of the video field, that is, EOI and the beginning, that is, SOI.

FIG. 2B shows a state in which the header data H is inserted by packing dummy data added to make the variable-length video data a fixed rate. At this time, the audio data Although A is not necessarily located at the head of the block, each data can be easily separated on the decoder side by the dummy size DS of the field header information. Note that B in FIG. 2 is a virtual one for simplifying the explanation, and for example, in terms of timing, it is actually delayed from A in FIG. The process of packing or removing the dummy data D of FIG. 2A is performed by the multiplexer 34E and the buffer 37E, but is performed when the dummy data D is sent from the video buffer 15 to the I / O data bus 31 via the end detection circuit 16. It is also possible to do so.

FIG. 2C shows the write timing control signal W for each transmission data block of FIG. 2B to the hard disk device 39. At such a write timing, by sending a pause control signal (EXIN) as shown in D of FIG. 2 from the dummy counter 18 to the buffer control circuit 36E, as shown in E of FIG. Is paused. That is, the dummy counter 18 outputs the pause control signal and sends it to the buffer control circuit 36E when the integrated value of the number of words of the dummy data D exceeds the number of words for one block. The buffer control circuit 36E controls the buffer 37E and the hard disk device 39 to suspend writing for one block. On the other hand, at the time of reproduction or decoding, as will be described later, conversely, the reading of data from the hard disk device to the buffer may be stopped, and the output from the buffer to the I / O data bus may be stopped.

The operation of controlling the data format at the time of recording data or encoding will be described below with reference to FIG. That is, the data obtained by compression-encoding the video and audio signals is divided into blocks, which are recording units of the hard disk device, for example, sector units, as shown in FIG. Of these, the dummy data is truncated and left-justified as shown in FIG. However, since writing to the hard disk device is performed in block units, as shown in E of FIG.
After the block shift occurs, that is, when the integrated value of the dummy data amount exceeds one block, the pause (EXI
N) is enabled. When the dummy data is truncated, the packed dummy part becomes the boundary of the video field,
Here, the field header H is added to describe the number of words of the truncated dummy data. This allows
At the time of decoding, it is possible to shift each switching point of each data such as audio and video, and branch and separate each data without contradiction.

FIG. 3 shows the format of data to be recorded / reproduced on / from the hard disk device 39, and one block is K words. Before truncating the dummy data, one block K word is from audio data to the next audio data, and therefore the number of words from audio data A in block B2 to header data H at the field end of video data V1 is L, for example. When the number of words of dummy data written in this field header is D, the number of words from this field header to the next audio data A is K-L-D. Further, the number of words N up to the next field header is also written in this field header.

As the hard disk device 39, various signal recording devices such as a magneto-optical disk device or a disk array device composed of a plurality of these can be used.

Next, FIG. 4 shows an example of the configuration on the decoder side corresponding to the encoder configuration of FIG. In FIG. 4, the data read from the hard disk device 39 in block units is sent to the multiplexer 34D via the buffer 37D. The hard disk device 39 and the buffer 37D are the buffer control circuit 36D.
Is controlled by. These multiplexers 34
As described above, the D, the buffer control circuit 36D, and the buffer 37D are the multiplexers 34 on the encoder side of FIG.
E, the buffer control circuit 36E, and the buffer 37E may be shared. The data from the multiplexer 34D is
It is sent to the I / O data bus 31.

The data from the I / O data bus 31 is sent to the video buffer 45, the audio buffer 55 and the rate control circuit 43 via the header detection circuit 41. Further, the word clock CLK from the multiplexer 34D is the header detection circuit 41 and the block counter 42.
1 from the rate control circuit 43.
A pause control signal (EXIN) corresponding to the pause control signal from the dummy data counter 18 on the encoding side is sent to the buffer control circuit 36D. The pause control signal causes the hard disk device 39 to move to the buffer 37.
The reading of data into D is stopped, and the buffer 37
Data output from D to the I / O data bus 31 via the multiplexer 34D is suspended.

Data control at the time of decoding is performed by monitoring the field header, and each field header is monitored based on information such as the number of words of the dummy data in the field header and the number of words up to the next field header. Data is being separated. That is, the enable signal EN is sent from the header detection circuit 41 to the block counter 42 and the rate control circuit 43, and the header data is taken into the rate control circuit 43 when the field header is detected. The word number of the dummy data of the header data is sent to the block counter 42 as a decrement value. The block counter 42 is the multiplexer 3
The word clock CLK from 4D is counted, and the enable signal EN is sent to the video buffer 45 and the audio buffer 55 based on the information on the block format, the information on the number of dummy data words, and the like. That is, when the field header appears and the rate control circuit 43 reads the word number D of the dummy data, the count value of the block counter 42 is decremented by the word number.
Actually, the number of words up to the next audio data is K-L-D as described above, where L is the count value from the previous audio data, and this is used by the block counter 42 in the video buffer. By controlling the data reading of the 45 and the audio buffer 55,
It is possible to normally branch or separate each data.

The video data taken in the video buffer 45 is sent to the video decoder 46, subjected to the compression encoding processing and the symmetric expansion decoding processing in the video encoder 14 of FIG. (D /
A) It is converted into an analog video signal by the converter 47 and taken out from the output terminal 49.

The audio data taken in the audio buffer 55 is sent to the audio decoder 56, subjected to the compression encoding processing and the expansion decoding processing symmetrical to the audio encoder 24 of FIG. It is converted into an analog audio signal by the converter 57 and taken out from the output terminal 59.

As described above, the AV server of this embodiment uses a plurality of hard disk devices 39 in parallel to achieve high throughput, and has a multi-channel configuration in which a plurality of encoder circuit units 10 in FIG. 1 are also used. Therefore, from the header detection circuit 41 of FIG.
It is assumed that a plurality of decoder circuit units 40 up to 59 are also used and the input and output are each a plurality of channels.

A specific example of the configuration of the entire system will be described with reference to FIG. This information data recording / reproducing system is a system that includes a plurality of recording / reproducing devices using a disc-shaped recording medium and records and reproduces a video signal and an audio signal, that is, an AV server system.

Specifically, this AV server system records a large amount of data obtained by digitizing an AV material of an analog signal such as a commercial or a movie, and supplies the AV material to a plurality of channels simultaneously upon request. It is possible system. By using a plurality of hard disks as a recording medium for AV data, each AV material can be randomly accessed unlike the case where a conventional video tape recorder using a tape, that is, a VTR is used. This AV server system can be used for various purposes such as automatic commercial transmission, provision of karaoke, and language learning.

First, during data recording, analog AV data is input from a plurality of input channels. In the specific example of FIG. 5, the analog AV data is the signal input terminal 104,
It is input from 105 or the like. Each input analog AV data is digitized by the analog / digital (A / D) converters 108 and 109, and then the encoder 1
It is compressed at 12, 113. This is to increase the data transfer rate by compressing the digitized data because it is large in size. As a compression method, a method such as MPEG of a color moving image coding system or JPEG of a color still image coding system is generally used.

The digitally encoded data input from a plurality of input channels are sequentially input to the time division multiplexing block 114 with the timing controller 115 slightly shifting the time for each channel. The data from a certain channel is divided into a certain unit, for example, every 2 bytes for the number of hard disks, and recorded on each hard disk. Here, a hard disk is generally a problem regarding the data transfer capability of the AV server system. Therefore, by dividing the data into a plurality of hard disks and recording the data, the data transfer rate of the hard disk groups can be doubled by almost the same number.

The data time-division multiplexed by the time-division multiplexing block 114 is the timing controller 11
Under the control of 6, the data is written in the buffers 117, 118, and 119 with a certain unit of time, for example, every 2 bytes, with a slight time shift. At this time, the timing controller 11
6 controls which buffer of which time data is written. The buffers 117, 118, 119
The data written to the hard disk 12 is written to the hard disk 12 by the device control blocks 120, 121 and 122, respectively.
3, 124 and 125.

The above timing controller 11
6 and each device control block 120, 121, 122 is controlled by the server control block 126. In addition, the hard disks 123, 124,
Application information related to the data divided into 125 and recorded, for example, information such as a title is input from an input device of the host computer 101 (not shown),
It is managed by the application control block 127.

Next, at the time of data reproduction, the host computer 101 specifies which data is output to which output channel. This designation is made from the application control block 127 to the server control block 12
6 is transmitted, and where on the hard disk the desired data is recorded is specified. This information is transmitted to each device control block 120, 121, 122. Based on the above information, the hard disks 123, 1 are controlled by the device control blocks 120, 121, 122.
Data is read from 24 and 125, and each buffer 11
7, 118, 119. Each buffer 11
The data that is divided into 7, 118, and 119 is sent to the time division multiplexing block 114 under the control of the timing controller 115, and is reassembled into the original compressed data in the time division multiplexing block 114. .
This data is supplied to the desired output channel under the control of the timing controller 115. timing·
The compressed data from the time division multiplexing block 114 is sent to the decoders 110 and 111 under the control of the controller 115. The decoders 110 and 111 decompress the sent compressed data. The decompressed data is converted into the original analog AV material by the digital / analog (D / A) converters 106 and 107, and output from the signal output terminals 102 and 103.

The present invention is not limited to the above embodiment, but can be similarly applied to the case of recording and reproducing only variable length data such as the above video data. Further, various information signals other than the above video signal and audio signal can be used, and can be easily applied to the case of transmitting two or more information signals. Further, as a recording / reproducing apparatus using a disc-shaped recording medium, in addition to a hard disk device, a magneto-optical disc recording / reproducing apparatus,
It is also possible to use a so-called disk array device or the like provided with a plurality of disk-shaped recording media.

[0053]

As described above, according to the information signal recording method of the present invention, the amount of data per unit time obtained by compression-encoding the first input data at the first constant time intervals can be reduced. Dummy data is added to the changing variable length data to form fixed rate variable length data with a constant data rate, and this dummy data is removed and recorded on the recording medium in the block unit, and When the data amount exceeds the one block, the recording on the recording medium is stopped by the one block, so that the use efficiency of the recording medium or the apparent recording capacity can be improved.

According to the information signal reproducing method of the present invention, the variable length data read from the recording medium is removed when the recording medium recorded by the information signal recording method is reproduced. Since dummy data is added to form a fixed rate, and decompression decoding is performed and reproduction is performed at the first constant time intervals, decoding can be performed without trouble. in this case,
By recording information indicating the amount of the deleted dummy data in the recording medium together with the variable length data,
Dummy data can be added easily and accurately.

Further, according to the information signal recording apparatus of the present invention, the variable length data having the variable data amount per unit time, which is obtained by compression-encoding the first input data at the first constant time intervals, is obtained. A unit for adding dummy data to form fixed-rate variable-length data having a constant data rate, a unit for removing the dummy data and recording the data on the recording medium in block units, and a data amount of the dummy data is When the above 1 block is exceeded, the recording onto the recording medium is performed according to the above 1
Since the recording medium has means for controlling the stop only in block units, the recording efficiency or recording capacity of the recording medium can be increased.

Furthermore, an information signal reproducing apparatus according to the present invention is a reproducing apparatus for reproducing a recording medium recorded by the above-mentioned information signal recording method or apparatus, wherein the variable length data read from the recording medium is the above-mentioned. By including means for adding the removed dummy data to obtain a fixed rate, and means for expanding and decoding the fixed rate variable length data at the first constant time intervals and reproducing the data, the decoding is performed. It can be done effectively. Also in this case, the dummy data can be added easily and accurately by recording the information indicating the amount of the deleted dummy data in the recording medium together with the variable length data.

Further, the fixed length data having a constant amount of data per unit time obtained by compressing and encoding the second input data every second constant time is combined with the variable length data, and By recording the data in the recording medium in blocks for each block time, it is possible to easily and reliably separate these data during reproduction.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of an encoder side for video and audio data used in an embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation at the time of encoding with the configuration of FIG.

FIG. 3 is a diagram showing an example of a block format of data used in an embodiment of the present invention.

FIG. 4 is a block diagram showing an example of the configuration on the decoder side of video and audio data used in an embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of an information data recording / reproducing system to which an embodiment of the present invention is applied.

FIG. 6 is a diagram for explaining an example of digitization and compression encoding of a video signal.

[Fig. 7] Fig. 7 is a diagram for describing an example of digitization and compression encoding of an audio signal.

FIG. 8 is a diagram for explaining a difference between a data rate and a line transmission rate.

[Explanation of symbols]

 14 Video Encoder 15 Video Buffer 16 End Detection Circuit 17 Block Counter 18 Dummy Data Counter 24 Audio Encoder 25 Audio Buffer 34E, 34D Multiplexer 36E, 36D Buffer Control Circuit 37E, 37D Buffer 39 Hard Disk Drive 41 Header Detection Circuit 42 Block Counter 43 Rate Control Circuit 46 Video decoder 56 Audio decoder

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[Procedure amendment]

[Submission date] January 24, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The analog audio signal shown in FIG. 7A is 51 when the sampling frequency is 44.1 kHz.
The time T _A corresponding to two samples, that is, T _A = 512 / (44.1 × 10 ³ ) (sec) ≈11.6 (msec) is compression-encoded as a unit. That is, one sample 16 bits 512 per channel shown in B of FIG.
2 channels for sample (stereo), 5
12 × 16 bits × 2 channels are compressed and encoded,
It is fixed length data of 212 × 8 bits × 2 channels shown in C of FIG. The unit time of this fixed length data, for example, the data amount per second, that is, the data rate R
_A is R _A = 212 × 2 × 8 / T _A (bit / sec = bps). The unit time T of such audio signal compression
_A has nothing to do with the unit time T _V of compression of the video signal, and does not have a simple integer ratio relationship.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

Claims (8)

[Claims] 1. A recording medium in which variable length data obtained by compressing and encoding first input data at a first fixed time interval and having a variable amount of data per unit time is blocked at a constant block time. In the information signal recording method of recording on the recording medium, dummy data is added to the variable-length data to form fixed-rate variable-length data having a constant data rate, and the dummy data is removed and recording is performed on the recording medium in block units. And the data amount of the dummy data is 1
When the number of blocks is exceeded, the recording on the recording medium is performed as described above
An information signal recording method characterized by stopping for a block. 2. The information signal recording method according to claim 1, wherein information indicating the amount of the deleted dummy data is recorded on the recording medium together with the variable length data. 3. The fixed length data having a constant amount of data per unit time, which is obtained by compressing and encoding the second input data every second constant time, and the variable length data are synthesized, and 3. The information signal recording method according to claim 1, wherein the information signal is recorded on a recording medium in blocks for each block time. 4. A fixed data rate is fixed by adding dummy data to variable length data having a variable amount of data per unit time, which is obtained by compression-encoding the first input data at every first fixed time. An information signal reproducing method for reproducing a recording medium recorded as rate-changed variable-length data, in which the dummy data is removed from the fixed-rate variable-length data, and recorded at a fixed block time. An information signal reproducing method, characterized in that the removed dummy data is added to variable length data read from a recording medium to make a fixed rate, and the data is expanded and decoded at the first constant time and reproduced. 5. The recording medium records information indicating the amount of deleted dummy data together with the variable length data, and the variable read out from the recording medium based on the dummy data amount information. 5. The information signal reproducing method according to claim 4, wherein dummy data is added to the long data to make a fixed rate. 6. The fixed-length data having a constant data amount per unit time, which is obtained by compression-encoding the second input data every second fixed time, and the variable-length data, on the recording medium. 6. The information signal reproducing method according to claim 4 or 5, wherein is recorded after being combined. 7. A recording medium in which variable length data having a variable amount of data per unit time, which is obtained by compression-encoding the first input data at a first fixed time interval, is blocked at a constant block time interval. In the information signal recording apparatus for recording in the above, a unit for adding dummy data to the variable length data to form fixed rate variable length data at a constant data rate; An information signal recording method comprising: means for recording on a medium; and means for controlling recording on the recording medium by the unit of one block when the data amount of the dummy data exceeds the one block. 8. A fixed data rate is fixed by adding dummy data to variable length data having a variable amount of data per unit time, which is obtained by compression-encoding the first input data every first fixed time. An information signal reproducing apparatus which reproduces a recording medium recorded as rate-variable variable-length data, in which the dummy data is removed from the fixed-rate variable-length data, and the blocks are recorded at a constant block time. A unit for adding the removed dummy data to the variable length data read from the recording medium to obtain a fixed rate; and decompressing and decoding the fixed rate variable length data at the first constant time intervals. An information signal reproducing apparatus comprising: a reproducing unit.