JPH0821199B2 - Digital signal dubbing method - Google Patents

Description

The present invention relates to a digital signal dubbing method for a digital recording device such as a digital VTR.

2. Description of the Related Art In conventional digital audio equipment and digital VTR dubbing, digital signals in the form of A / D converted voice and images have been used. In the following, a digital VTR will be taken as an example.

FIG. 2 is a block diagram showing a conventional digital VTR dubbing method, where 1 is an A / D converter, 2 is an error correction encoder, 3 is a recording encoder, 4 is a magnetic recording system, and 5 is recording. Decoder, 6 is error correction decoder, 7 is modifier, 8 is D / A
It is a converter.

In the digital dubbing method of the digital VTR constructed as described above, the digital signal at the dubbing input is inputted after the A / D converter 1. Then, an error correction code is added by the error correction encoder 2 and is recorded on the magnetic tape through the recording encoder 3. At the time of reproduction, the reproduction data passes through the recording / decoding device 5, is error-corrected by the error-correction decoding device 6, and the uncorrectable error is corrected / interpolated by the correction device 7. The dubbing output signal is taken out from after the modifier 7 and before the D / A converter 8.

Problems to be Solved by the Invention However, in the above configuration, when the error is uncorrectable on the reproduction output side and the correction is made, the device on the recording input side records the corrected data as correct data. Had a point. Further, when compression (high-efficiency coding) is performed in a digital VTR or the like, if digital output is performed after compression / decoding, the data rate for dubbing is higher than the recording data rate, which is disadvantageous.

In view of such a point, the present invention provides a digital signal dubbing method which eliminates the recording of modified data as correct data and can dubb at a compressed low data rate when compression (high efficiency coding) is used. The purpose is to

According to the present invention, a digital signal to which an error correction code is added is corrected only for errors that can be corrected on the reproduction output side, and a digital output is made in a form in which the error correction code is added, and a recording input is made. On the side, a digital signal dubbing method is characterized in that the signal to which the error correction code has been added is input as a digital signal.

Operation The present invention does not record the corrected data as correct because it outputs digitally with the error correction code added and does not pass through the correction device by the method described above.
However, since it has been corrected, data deterioration can be suppressed. Also, error correction coding can be omitted on the recording input side. Furthermore, when compression coding is included, dubbing can be performed at a low compressed data rate.

Embodiment FIG. 1 is a block diagram showing a digital VTR dubbing method in an embodiment of the present invention. 10 in FIG.
Is an A / D converter, 11 is a compression encoder, 12 is an error correction encoder, 13 is a recording encoder, 14 is a magnetic recording system, 15 is a recording decoder, 16 is an error correction decoder, Reference numeral 17 is a compression decoder, 18 is a modifier, and 19 is a D / A converter.

The operation of the digital dubbing method of the digital VTR configured as described above will be described below. The VTR of this embodiment is the same as the VTR of the conventional example except that compression (high efficiency coding) is included. The compression encoder 11 functions to reduce the redundancy of image information and lower the data rate, and the compression decoder 17 restores the original data rate by the inverse conversion.

Digital output for dubbing is an error correction decoder
It will be taken out after 16. With this dubbing output, correctable errors are corrected, uncorrectable errors are not corrected, and digitally output with an error correction code added. For simplicity, it is assumed that the data order of dubbing output is the same as the data order when recording. On the recording input side, the dubbing data is input after the error correction encoder 12. Since the error correction code is added to the dubbing data, it is not necessary to encode it again. Since the error is corrected on the reproduction output side, the number of errors does not increase unnecessarily. When playing back images on the device that receives the dubbing input,
Based on the reproduced data, the uncorrectable error is corrected and the image is output.

As described above, according to this embodiment, the data modified at the time of dubbing is not recorded as correct data, and the dubbing can be performed at a low compressed data rate.

Although the digital VTR is taken up in the embodiment,
The same dubbing method can be applied to digital audio and other digital recording equipment.

Effects of the Invention As described above, according to the present invention, data corrected at the time of dubbing is not recorded as correct data, and when compression (high efficiency coding) is included,
Dubbing is possible at a compressed low data rate, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing a digital VTR dubbing method of an embodiment of the present invention, and FIG. 2 is a conventional digital VTR dubbing method.
It is a block diagram which shows the dubbing method of VTR. 1 ... A / D converter, 2 ... error correction encoder, 3 ... recording encoder, 4 ... magnetic recording system, 5 ... recording decoder,
6 ... Error correction decoder, 7 ... Modifying device, 8 ... D / A converter, 10 ... A / D converter, 11 ... Compression encoder, 12 ...
Error correction encoder, 13 ... Recording encoder, 14 ... Magnetic recording system, 15 ... Recording decoder, 16 ... Error correction decoder,
17 …… compression / decoder, 18 …… retoucher, 19 …… D / A converter.

Claims (1)

[Claims] 1. A digital signal to which an error correction code has been added corrects only correctable errors on the reproduction output side and outputs digitally in the form in which the error correction code has been added, and the error input code on the recording input side. A digital signal dubbing method, characterized in that the signal with the signal added is used as a digital input.