JPH06302103A - Digital information recording device and digital information reproducing device - Google Patents

Abstract

PURPOSE:To provide a digital information recording device and a digital information reproducing device which effectively compresses, records and reproduces plural channel information data while keeping at least one channel to be compatible with a conventional type. CONSTITUTION:During a recording, right channel data R are compressed and encoded by a first data compression encoding circuit 12, left channel data L are compressed and encoded by a second compression encoding circuit 13 and completion codes are added to the final section of respective data train. Moreover, error correction codes and synchronization ID codes are added, NRTZ modulated by a modulation circuit 4 and recorded to a tape 6. During a reproducing, the reproduced data from the tape 6 are separated by a data separating circuit 15, the right channel data R are decoded by a first data expansion decoding circuit 16 and the left channel data L are decoded by a second data expansion decoding circuit 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital information recording apparatus and a digital information reproducing apparatus for recording and reproducing by compressing digital information of a plurality of channels such as stereoscopic video data.

[0002]

2. Description of the Related Art Conventionally, when a video signal is digitized and recorded in a digital VTR, it is possible to significantly reduce the consumption of a recording medium such as a tape by performing a predetermined data compression before recording. .

FIG. 5 is a block diagram showing an example of a conventional digital VTR.

First, at the time of recording, the input digital video data sampled at a predetermined frequency is DCT.
The data is compressed by the data compression encoding circuit 1 such as (discrete cos-in conversion) and the end code E is added to the end of the data, and then the predetermined error correction code P is added by the error correction code addition circuit 2. Further, after the synchronization code and the ID code S indicating the block number, the track number, etc. are added by the synchronization and ID addition circuit 3, modulation such as NRZI modulation is performed by the modulation circuit 4, and recording is performed on the tape 6 by the recording head 5. To be done.

FIG. 6 shows the structure of recording data. The data of one fixed length unit, which is a part of the video data of one screen, is compressed to fit within the data capacity A for recording in a predetermined sector of the tape. Therefore, the data amount of the compressed data is B (<A). This data amount B varies depending on the nature of the original data. Therefore, an indefinite non-data portion N occurs at the end of the data string, but the subsequent processing is performed assuming that data also exists in this portion.

Furthermore, after the compressed data is divided into a plurality of blocks, synchronization and ID are added at the beginning of each block.
A code S and an error correction code P are added to the last part of the block to form a synchronous block. Then, the plurality of synchronization blocks are collectively recorded in a predetermined recording area (sector) of the tape.

Next, at the time of reproduction, the data recorded on the tape 6 is reproduced by the reproducing head 7, and the equalization demodulation circuit 8 performs waveform equalization and data demodulation. Further, after the synchronization and ID detection circuit 9 detects the synchronization code and the ID code, and the error detection and correction circuit 10 performs error detection and correction of the data,
The data decompression / decoding circuit 11 performs decompression / decoding to obtain original digital video data.

[0008]

However, the above-mentioned conventional digital VTR can record only single-channel video data, and video data of a plurality of channels, for example, two stereoscopic video signals having parallax between left and right. A digital information recording apparatus and a digital information reproducing apparatus which are compressed and can be efficiently recorded, and are compatible with each other so that one of a plurality of channels can be reproduced by a digital VTR for a single channel having the same conventional format. The device has not been proposed yet.

The present invention has been made in view of the above points, and a digital information recording apparatus capable of efficiently compressing and recording / reproducing information data of a plurality of channels while at least one channel is compatible with the conventional system. And a digital information reproducing apparatus.

[0010]

According to the present invention, there is provided first data compression coding means for compressing and coding a data string of a first channel of a fixed length unit among a plurality of channels into a first data string of a predetermined data amount, Second data compression coding means for compressing and coding a data string of a second channel of a fixed length unit among the plurality of channels into a second data string of a predetermined data amount, and an end code is added to the end of the first data string. The digital information recording apparatus is provided with an end code adding means for recording, and a recording means for recording the first data string, the end code and the second data string in a predetermined recording area of a recording medium in this order.

Further, according to the present invention, a first data string obtained by compression-encoding a data string of a first channel of a fixed length unit among a plurality of channels into a predetermined data amount, and an end added to the end of this first data string. Digital information for reproducing a recording medium in which a code and a second data string obtained by compression-coding a data string of a second channel of a fixed length unit among the plurality of channels into a predetermined data amount are recorded in a predetermined recording area in this order. A reproducing apparatus, which reproduces data in the predetermined recording area, selecting means for selecting the first and / or second data string from the reproduced data based on the end code, and an output of the selecting means. The digital information reproducing apparatus is provided with a data decompression / decoding means for decompressing and decoding and outputting a data string of the first and / or second channels.

[0012]

According to the present invention, the data sequence of the first channel is compression-encoded into the first data sequence, and the data sequence of the second channel is compression-encoded into the second data sequence.
An end code is added to the end of the first data string. Then, the first data sequence, the end code, and the second data sequence are recorded in a predetermined recording area of the recording medium in this order.

Further, according to the present invention, the data reproduced from the predetermined recording area is selected from the first and / or second data strings based on the end code. The selected data is decompressed and decoded into a data string of the first and / or second channels.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a digital VTR for recording / reproducing stereoscopic video data will be described below with reference to the drawings. FIG. 1 shows a digital VTR in this embodiment.
FIG. 4 is a schematic block diagram of the same, in which the same parts as those in the conventional example are designated by the same reference numerals and the description thereof is omitted.

First, during recording, the right channel data R of the stereoscopic image data sampled at a predetermined frequency is processed by the first data compression encoding circuit 12 and left channel data L is obtained.
Are compression-encoded by the second data compression encoding circuit 13 and added by the addition circuit 14. As in the conventional case, the added data is added with the error correction code P, the synchronization and the ID code S, and then NRZI modulated and recorded.

The details of the first and second data compression encoding circuits, which are the features of this embodiment, are shown in FIG. 2 and the structure of the recording data is shown in FIG.

The first data compression coding circuit 12 comprises a frame memory 120, a DCT circuit 121, a delay circuit 122 and an end code adding circuit 123. The right channel data R of one fixed length unit is stored in the frame memory 12
The data is temporarily stored in 0, divided into a plurality of blocks of, for example, 8 × 8 pixels, then orthogonally transformed by the DCT circuit 121 and compressed. The DCT circuit 121 is set so that the upper limit of the amount of data after compression is A1. Then, as a result of being compressed, the data of the data amount B1 is obtained,
After being delayed by the delay circuit 122 by the time required for the compression operation of one fixed length unit, the end code adding circuit 123
Is added and output.

On the other hand, the second data compression coding circuit 13 includes a frame memory 130, a delay circuit 131 and a DCT circuit 13.
2. Capacity calculation circuit 133 and end code addition circuit 134
Composed of. Then, the left channel data L of one fixed length unit is temporarily stored in the frame memory 130, delayed by the delay circuit 131 by the time required for the compression operation of one fixed length unit, and then orthogonally transformed and compressed by the DCT circuit 131. . Here, the capacity calculation circuit 133 subtracts the data amount B1 of the right channel data R after compression and the data amounts of the first and second end codes from the total capacity A recordable in one sector to obtain the left channel data. A compressible data amount A2 of L is calculated and supplied to the DCT circuit 132.

Therefore, the DCT circuit 132 is set so that the upper limit of the amount of data after compression is A2. Then, as a result of the compression, data of the data amount B2 is obtained, and the second end code is added and output.

The delay circuit 1 is provided before the DCT circuit 132.
31 is arranged because the compression ratio of the left channel data L is set by observing the result of compressing the right channel data R. Further, the delay circuit 123 is arranged in the subsequent stage of the DCT circuit 122 because the right channel data R
This is because the output and the left channel data L are output at the same time.

Then, the compressed data is divided into a plurality of blocks, and synchronization and I are added at the beginning of each block.
The D code S and the error correction code P are added to the end of the block to form a synchronization block. Then, the plurality of synchronization blocks are recorded in a predetermined sector of the tape.

On the other hand, at the time of reproduction, the data recorded on the tape 6 is reproduced by the reproducing head 7 as in the conventional case, and the equalization demodulation circuit 8 performs waveform equalization and data demodulation. Further, after the synchronization and ID detection circuit 9 detects the synchronization code and the ID code and the error detection and correction circuit 10 performs error detection and correction of the data, the data separation circuit 15 outputs the right channel data R and the left channel data L. And are separated. Each separated data is decoded into original data by the first and second data decompression / decoding circuits 16 and 17, respectively.

Next, FIG. 4 shows a second embodiment of the present invention.
The feature of this embodiment lies in the reproducing side, and the error detection / correction circuit 10
Is output to one data expansion / decoding circuit 11 via the data selection circuit 18. The data selection circuit 18 selects and outputs from the beginning of the sector to the first end code when the right channel data R is selected by the selection signal n and outputs the first channel when the left channel data L is selected.
Select and output from after the end code of to the end of the data string. Then, the data decompression decoding circuit 11 decodes the right channel data R or the left channel data L.

Furthermore, FIG. 5 shows a third embodiment of the present invention. The feature of this embodiment is that a third data expansion / decoding circuit 19 for expanding / decoding the output of the first data compression / encoding circuit 13 for encoding the right channel data R is arranged, and the right data decoded by the third data expansion / decoding circuit 19 is arranged. The difference is that the difference data between the channel data R ′ and the left channel data L is encoded by the second data compression encoding circuit 13. That is, the adder circuit 1
The four outputs are the sum of the encoded right channel data R and the encoded difference data.
Therefore, since the difference data between R and L that are correlated with each other is compression-encoded, the compression efficiency is better than that of the left channel data L itself.

During reproduction, the second data decompression decoding circuit 17 adds the decoded difference data and the right channel data R decoded by the first data decompression decoding circuit 16 to the left. Decode the channel data L.

In the present embodiment, the output of the third data compression encoding circuit 19 is used to obtain the difference between the right channel data R and the left channel data L during recording. The error due to the compression / expansion of No. 1 is configured not to be accumulated in the compression / expansion result of the left channel data L. The third data expansion / decoding circuit 19 may be shared with the first data expansion / decoding circuit 16 or may be accumulated. The right channel data R may be directly supplied to the second data compression encoding circuit 12 when the error due to the error can be ignored.

When the tape on which the stereoscopic video signal is recorded by the digital VTR of the above embodiment is reproduced by the single-channel digital VTR having the same conventional format as shown in FIG. 6, the first end from the head of the sector is completed. Since only the data up to the code is decoded, the right channel data R can be reproduced without any problem although the compression ratio is different, and the recording medium recorded by the conventional digital VTR can be reproduced by the digital VTR of the above embodiment without any problem. As a result, compatibility is maintained.

In the above embodiment, the first and second input data strings are stereoscopic video data, but the second data string is a data string for temporally interpolating the first data string. By outputting the two data strings to the scale in time, it is possible to reproduce an image with smooth movement.

Also, by recording the first data string as a band of a normal television signal and the second data string as a high definition component, recording and reproduction of a high definition television signal while maintaining compatibility with a conventional digital VTR. Can be done.

The first and second data strings may be audio data other than video data or other information data.

Further, the input data string may be a plurality of three or more data strings.

[0032]

As described above, according to the present invention, information data of a plurality of channels can be efficiently compressed and recorded / reproduced.

In addition, by adding an end code to the end of the first data string obtained by compression-encoding the data string of the first channel of the plurality of channels and then recording from the beginning of the predetermined recording area of the recording medium, the conventional method is used. Since it can be reproduced by a digital information recording / reproducing apparatus having the same single-channel recording format, and the recording medium recorded by the digital information recording / reproducing apparatus can be reproduced by the digital information reproducing apparatus of the present invention. Compatibility can be maintained.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital VTR according to an embodiment of the present invention.

FIG. 2 is a detailed block diagram of first and second data compression encoding circuits.

FIG. 3 is a diagram showing a data structure of the present invention.

FIG. 4 is a block diagram of a digital VTR according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a digital VTR according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a digital VTR in a conventional example.

FIG. 7 is a diagram showing a data structure of a conventional example.

[Explanation of symbols]

 12 first data compression coding circuit 13 second data compression coding circuit 14 addition circuit 15 data separation circuit 16 first data expansion decoding circuit 17 second data expansion decoding circuit 18 data selection circuit

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Claims (7)

[Claims] 1. A first fixed length unit of a plurality of channels
First data compression coding means for compressing and coding a channel data string into a first data string having a predetermined data amount; and a second channel data string of a fixed length unit of the plurality of channels, a second data having a predetermined data amount. Second data compression encoding means for compressing and encoding a sequence, end code adding means for adding an end code to the end of the first data sequence, and the first data sequence and the end in a predetermined recording area of a recording medium. A digital information recording apparatus comprising a code and a recording means for recording the second data sequence in this order. 2. The second data compression coding means compresses the data so that the data amount of the second data string is smaller than the difference between the data amount of the first data string and the data capacity of the predetermined recording area. The digital information recording apparatus according to claim 1, wherein 3. A first fixed length unit of a plurality of channels
A first data string obtained by compression-encoding a channel data string into a predetermined data amount, an end code added to the end of the first data string, and a data string of a second channel of a fixed length unit among the plurality of channels are displayed. A second information string compression-encoded into a predetermined data amount is a digital information reproducing apparatus for reproducing a recording medium recorded in a predetermined recording area in this order, and means for reproducing data in the predetermined recording area, Selection means for selecting the first and / or second data sequence from the reproduced data based on the end code, and data decompression for decompressing and decoding the output of the selection means to output the data sequence of the first and / or second channel. A digital information reproducing apparatus comprising a decoding means. 4. The digital information recording apparatus according to claim 1, wherein the data sequence of the second channel is a difference data sequence with respect to the data sequence of the first channel and a data sequence having a correlation. 5. The data sequences of the first and second channels are stereoscopic image data having parallax with each other.
The described digital information reproducing apparatus. 6. The digital information recording apparatus according to claim 1, wherein the data string of the second channel is a difference data string with a data string having a correlation with the data string of the first channel. 7. The data strings of the first and second channels are stereoscopic image data having parallax with each other.
The described digital information reproducing apparatus.