JPH01296460A - Still picture signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To make the error correction of an error uncorrectable part perfect by allocating an information bit area, which is added to a video signal, to an error flag area or allocating the information bit area with decrease in the number of quantizing bits in the video signal. CONSTITUTION:When a copying source disk is set to a recording and reproducing device 7 and reproduced, for the video signal of 8 bits and the information bit signal of 1 bit, an error is corrected in an error correcting circuit 13 through a demodulating circuit 12 and an output is written to a memory 11 for normal reproducing or guided to a replacing circuit 15. The error flag signal, which shows a condition concerning a picture element to be error-uncorrectable in the circuit 13, is inputted to the replacing circuit 15 and an error flag to be shown in a symbol EF is replaced to the storing position of the information bit and added to the video signal of the 8 bits. Then, a 9-bits signal for copying is generated. The output of the replacing circuit 15 is sent from a copying signal output terminal (h) through a memory 17 to a recording and reproducing part in a slave side. Thus, the error correction of the error uncorrectable part can be made perfect.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a disk copying method using a high-definition still image signal recording and reproducing apparatus for recording and reproducing high-definition still image signals on a recording medium such as an optical disk.

Conventional Technology In recent years, filing systems that use large-capacity, compact optical disks as peripheral storage devices for computers, etc. have been announced and released one after another, and the development of optical disk filing systems that can handle not only documents but also images is progressing. There is. In addition, in television technology, high-definition television (high-definition television), which has a scanning line that is more than twice as wide as the conventional NTSC system and a wider aspect ratio, is attracting attention as a new next-generation television system. Development of equipment in various fields, such as VTR1 video discs, is underway.

Based on the above background, the development of a high-definition optical disc filing system that records and reproduces high-definition and realistic high-definition still image signals using optical discs with high-speed search performance due to high recording density and random access function is underway. An example is reported in "High Definition Optical Disk Image File System" (Mizutani et al.: Television Science and Technology Report VR87-14).

On the other hand, copyright infringement through copying has recently become a problem in the publishing industry, music industry, etc., but high-definition video signals recorded and played back using optical discs are also copyright protected because they can record high-definition image signals. It is expected that this will become inevitable.

Recording and reproducing procedures in a conventional still image signal recording and reproducing device will be described below with reference to the drawings. First, the signal recording procedure will be explained.

FIG. 2(a) shows an example of a video signal processing section, in which a high-definition video signal taken in from a high-definition camera or scanner is digitized by an A/D converter 1 via an input terminal a, and recorded in a first memory 2. do. The video signal recorded in the memory 2 is subjected to appropriate signal processing such as band compression in the signal processing circuit 3, transferred to the second memory 4, and sent from the output terminal C to the recording/reproducing section. FIG. 2(b) shows an example of a recording/reproducing section, in which a video signal output from a video signal processing section is recorded in a third memory 5 via an input terminal, and an error correction code is encoded in an encoding circuit 6. etc. are added, and then recorded in the recording/reproducing device 7.

Next, the signal reproduction procedure will be explained. Recording and reproducing device 7
The video signal pre-recorded on the disc to be played back is subjected to error correction in the decoding circuit 8, and if error correction is not possible,
It is recorded in the memory 5 together with a status display signal that is an error flag indicating the status. The signal recorded in the memory 5 is sent to the video signal processing unit shown in FIG. 2(a) via the output terminal f, and is stored in the memory 4 via the playback signal input terminal d of the video signal processing unit. . In the error correction circuit 9, an error flag attached to a pixel whose error cannot be corrected as a result of error correction in the decoding circuit is used to detect a pixel in which an error has occurred, such as by interpolation of the previous line or interpolation from surrounding pixels. Performs interpolation processing and writes back to memory 2. The video signal recorded in the memory 2 is converted back to an analog signal by the D/A converter 10 and displayed on a display or the like via an output terminal. FIG. 3 schematically shows a method of connecting the video signal processing section and the recording/playback section when performing normal recording/playback. Further, FIG. 4 shows connections when copying a video signal already recorded on a disk to another disk using the conventional method. As you can see from this figure, the video signal played by the recording/playback section on the master side is once input to the video signal processing section, and after error correction is performed, it is copied and recorded by the recording/playback section on the slave side. .

Problems to be Solved by the Invention In the second example, when at least two recording and reproducing units are directly connected to each other in order to copy a disc by dubbing, etc., the error flag generated by the decoding circuit is not transmitted. Therefore, the video signal in the location where the error cannot be corrected will be recorded on the copy destination disk with an error, and as a result, the image information will be destroyed. This problem has been solved in that copying must be performed while error correction is performed, and the time required for copying increases while it corresponds to memory transfer.

On the other hand, if a disc is copied using this connection method, the content recorded on the copy source disc and the content recorded on the copy destination disc will be exactly the same, which is a desirable copy in terms of copyright issues. The problem was that it was not a good method.

In view of the above, the present invention enables a high-speed copying method that allows good error correction during playback even when copying is performed by directly connecting at least two recording/playback units, and also provides a method for copyright protection, etc. An object of the present invention is to provide a still image signal recording and reproducing device that differentiates the reproduced image quality between a copy source disc and a copy destination disc.

Means for Solving the Problems According to the present invention, there is provided a still image signal recording and reproducing device that records and reproduces a high-definition still image signal on a recording medium such as an optical disc, which converts an input video signal into a digital state. an A/D converter, a D/A converter that outputs an analog video signal, first and second memories having a capacity of at least one high-definition frame;
, a video signal processing unit configured of an error correction circuit that corrects a video signal that exists between a second memory and cannot be error corrected, and a signal exchanged between the video signal processing unit and the video signal; an encoding circuit comprising a switch for selecting a signal for direct copying, a correction code addition circuit for adding an error correction code, and a modulation circuit; a recording/reproducing device for recording and reproducing the encoded signal; A decoding circuit consists of a demodulation circuit that demodulates the signal reproduced by the recording/reproduction device and an error correction circuit that corrects errors in the demodulated signal, and a decoding circuit that outputs information bits when errors cannot be corrected by the error correction circuit. a recording/reproducing section connected to the latter stage of the video signal processing section, which includes a replacement circuit for replacing an error flag with an error flag; Either replace the information bits added to the signal with error flag bits for error correction, or reduce the number of quantization bits of the video signal to 1 when directly copying the recorded signal.
The feature is that the area generated by bit reduction is allocated as an error flag bit for error correction.

Effect of the present invention With the above-described configuration, at least two units We have realized a copying method that can completely correct errors in areas that cannot be corrected even when copying a disc by directly connecting the recording/playback unit, and further differentiate the reproduced image quality of the copy source disc and the copy destination disc. It can also be used for the purpose of protecting copyrights, etc.

Examples Examples of the present invention will be described below with reference to the drawings. It should be noted that parts having substantially different functions from those of the conventional example will be described using the same numbers as those of the conventional example.

Copying of a disc using the still image signal recording and reproducing apparatus of the present invention is realized by directly connecting the copying signal input/output terminals of at least two recording and reproducing units, as shown in FIG. FIG. 1 shows an embodiment of a still image signal recording and reproducing apparatus according to the present invention.

As a first embodiment of the present invention, the signal for one pixel is defined as an 8-bit video signal portion indicated by the symbol Do-D7 and an information bit indicated by the symbol ■, as shown in FIG. 6(a). A 1-bit signal is added to the most significant side of the video signal, making up a total of 9 bits. The contents of the signals recorded on the information bits are not specifically mentioned here, but for example, character information to be superimposed on the video signal may be stored in a bitmap format, or, for example, one word may be stored in 8 bits. Supplementary explanatory text about the recorded content, recording location, recording date and time, password, etc. should not be transmitted to the copy destination disk even if the disk is copied. The original data may be stored so that it exists only on the copy source disk.

First, the procedure for reproducing signals in the recording and reproducing unit on the master side, into which a copy source disk is set during copying, will be explained.

A copy source disk, on which a signal has been previously processed by the video signal processing section and recorded from the input terminal e of the recording and reproducing section via the memory 11, the encoding circuit 6, and the recording and reproducing device 7, is set in the recording and reproducing device 7. During reproduction, a signal consisting of an 8-bit video signal and a 1-bit information bit is passed through a demodulation circuit 12 and subjected to error correction by an error correction circuit 13. The output signal of the error correction circuit 13 is written to the memory 11 for normal reproduction via the conductor 14 and is also guided to the replacement circuit 15. Furthermore, a status display signal, which is an error flag, indicating the status of a pixel whose error cannot be corrected by the error correction circuit 13 is led to the replacement circuit 15 via a conductor 16. As shown in FIG. 6(b), the replacement circuit 15 replaces the error flag indicated by the 1-bit symbol EF with an information bit in the storage position of the information bit described above, and adds it to the 8-bit video signal, thereby creating a 9-bit image signal for copying. Generate a bit signal. The output signal of the replacement circuit 15 is sent as a copying signal via a memory 17 to a recording/reproducing section on the slave side from a copying signal output terminal.

Next, a description will be given of the signal recording procedure in the recording/reproducing unit on the slave side, where a copying destination disk for copying such as dubbing is recorded.

Since the recording/reproducing section on the master side and the recording/reproducing section on the slave side are directly connected, the signal sent from the copy signal output terminal of the recording/reproducing section on the master side is sent to the copy signal input terminal g of the recording/reproducing section on the slave side. The signal is input from the memory 17 and becomes one input of the switch 18 . Here, the switch 18 is used to select a signal for normal recording and a signal for copy recording, and operates so that the signal from memory 11 passes during normal recording, and the signal from memory 17 passes during copy recording. do. The signal that has passed through the switch 18 is guided to the encoding circuit 6, and after an error correction code is added by the correction code addition circuit 19, the signal is recorded on the copy destination disk via the modulation circuit 20 and copied by the recording/reproducing device 7. .

In the second embodiment of the present invention, the video signal is as shown in FIG. 7(a).
As shown in the figure, it is composed of 8 bits indicated by the conventional symbol DO-D7. In the signal reproduction procedure in the recording and reproducing section on the master side, the signal recorded on the copy source disk is reproduced by the recording and reproducing device 7, and the error correction circuit 13 performs error correction via the demodulation circuit 12. . The output signal of the error correction circuit 13 is written to the memory 11 for normal reproduction via the conductor 14 and is also guided to the replacement circuit 15. Furthermore, a status display signal serving as an error flag indicating the status of the pixel whose error cannot be corrected by the error correction circuit 13 is guided to the replacement circuit 15 via a conductor 16. As shown in FIG. 7 (1)), the substitution circuit 15 discards the lowest one bit of the 8-bit video signal, indicated by the symbol Do, and converts the entire signal into a 7-bit signal indicated by symbols D1 to D7. Shift 1 bit. An error flag indicated by the symbol EF for error correction is assigned to the area resulting from this. The output signal of the replacement circuit 15 is sent as a copying signal via a memory 17 to a recording/reproducing section on the slave side from a copying signal output terminal.

The signal recording procedure in the recording/reproducing section on the slave side is substantially the same as that in the first embodiment, so the explanation will be omitted here.

- When playing back a disc on which a video signal has been copied using the signal playback and recording procedure described above, the error flag recorded during the copying process is used to detect the error flag that is recorded during the copying process, and the error cannot be corrected when the copied disc is played back. If the error flag indicating that the error correction circuit 9 in the video signal processing section performs error correction using the error flag indicating that the error flag cannot be corrected when the copying operation is performed, the error flag indicating that the error cannot be corrected during the copying operation can be carried over when the copied disk is reproduced. This makes it possible to perform copying operations at high speed with maximum error correction ability without going through the video signal processing section. Furthermore, as shown in the first embodiment, the portion recorded in the information bits of the original copy source disk cannot be reproduced, and as shown in the second embodiment, the quantization of the video signal By reproducing a video signal with the number of bits reduced by 1 bit, it is possible to differentiate the reproduced image quality of the copy destination disk from that of the copy source disk.

Effects of the Invention The still image signal recording and reproducing device according to the present invention can perform copying at a higher speed than before by directly connecting only the recording and reproducing section.
Furthermore, it is possible to provide a difference in the reproduced image quality between the copy source disc and the copy destination disc for the purpose of copyright protection, etc., and this has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a recording and reproducing section in a still image signal recording and reproducing apparatus according to an embodiment of the present invention, and FIG.
) is a block diagram of a video signal processing unit in a conventional still image signal recording and reproducing apparatus, FIG. 2 (1)) is a block diagram of a recording and reproducing unit in a conventional still image signal recording and reproducing apparatus,
Fig. 3 is a system connection diagram for normal recording and reproduction of video signals, Fig. 4 is a conventional system connection diagram for copying a disc, and Fig. 5 is a system connection diagram of the present invention for copying a disc. System connection diagram of the embodiment, Fig. 6 (a
) is a configuration diagram of a video signal recorded on a copy source disk in the first embodiment of the present invention, and FIG. 6 (1)) is a configuration diagram of a video signal recorded on a copy destination disk in the first embodiment. 7(a) is a configuration diagram of a video signal recorded on a copy source disk in the second embodiment of the present invention, and FIG. 7(b) is a diagram of a video signal recorded on a copy destination disk in the second embodiment of the present invention. FIG. 3... Signal processing circuit, 6... Encoding circuit, 7...
Recording/reproducing device, 8... Decoding circuit, 13... Error correction circuit, 15... Replacement circuit, 18... Switch. Agent's name Patent attorney Toshio Nakao Idiot 1 idiot Tsuka

Claims (2)

[Claims] (1) Record a high-definition still image signal on a recording medium,
A still image signal recording and reproducing device to be reproduced, comprising an A/D converter for converting an input video signal into a digital state, a D/A converter for outputting an analog state video signal, and a capacity of at least one high-definition frame. 1st, 2nd with
and an error correction circuit that exists between the first and second memories and corrects a video signal for which error correction is not possible, and the video signal processing unit. An encoding circuit consisting of a switch for selecting a signal to be sent and received and a signal for direct copying of a video signal, a correction code adding circuit for adding an error correction code, and a modulation circuit, and recording and reproducing the encoded signal. a decoding circuit consisting of a recording and reproducing device that demodulates the signal reproduced by the recording and reproducing device, and an error correction circuit that corrects errors in the demodulated signal; a recording/reproducing section connected to the latter stage of the video signal processing section comprising a replacement circuit for replacing an error flag output when A still image signal recording and reproducing device characterized in that information bits added to a video signal during direct copying are replaced with error flag bits for error correction. (2) The still image signal recording and reproducing apparatus according to claim 1, wherein an area generated by reducing the number of quantization bits of the video signal by 1 bit during direct copying of the recorded signal is allocated as an error flag bit for error correction. .