JP3223971B2 - Video signal processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to signal processing of a video signal involving compression and expansion of image information.

[0002]

2. Description of the Related Art At the time of recording, a video signal is compressed by band compression or bit reduction and recorded on a predetermined medium, and at the time of reproduction, the original video signal is expanded by a process complementary to the compression process at the time of recording. It is going to get.

A video signal is compressed using a sub-sampling method using a vertical correlation of an image, a block coding method, or the like. Further, DCT (Discrete Cosine Transform), ADPCM (Adaptive Predictive Coding), ADRC (Adaptive Dynamic Range Coding) and the like are used as compression algorithms.

[0004]

By the way, various signals may be inserted at a predetermined timing in a vertical blanking period of a video signal. For example, any one of the following: Teletext signal ‥‥‥ 14-16H, 21H VITS ‥‥‥ 17H VIRS ‥‥‥ 18H Net queue ‥‥‥ 19-20H VITC ‥‥‥ 10-20H (H indicates horizontal period) Signal may be inserted.

However, as described above, all of these insertion signals are inserted only in a specific horizontal period of a vertical blanking period, and there is no vertical correlation like a video signal. When compressed and recorded, the waveform of the reproduced insertion signal is greatly deteriorated.

In this case, for example, a VITC can be converted into data and recorded and reproduced by providing a dedicated encoder and decoder. However, the dedicated encoder and decoder have a large circuit scale and cost. turn into.

The present invention has been made in view of the above points,
An object of the present invention is to provide a video signal processing device that can easily avoid deterioration of the waveform of a signal inserted during a vertical blanking period.

[0008]

According to the first aspect of the present invention, a first supply means for supplying a video signal and a second supply means for supplying a sub-signal inserted in a vertical blanking period of the video signal. Means, a compression circuit for performing a predetermined compression process using a vertical correlation on the video signal supplied from the first supply means, a sub-signal supplied from the second supply means, and compression by the compression circuit. And a synthesizing circuit for synthesizing the output video signal and outputting the synthesized video signal.

[0009]

In FIG. 1, reference numeral 10 denotes a video signal recording apparatus. At the time of recording, a video signal SV is supplied to a sync separation circuit 21 through an input terminal 11 to extract horizontal and vertical sync signals. , These synchronization signals are supplied to the timing signal forming circuit 22 and, for example, shown in FIGS.
As shown in the figure, the period TI of the insertion signal SI of the video signal SV
A signal ST which becomes "L" and becomes "H" during other non-insertion periods is formed, and this signal ST is supplied to the switch circuit 12 as its control signal.

Then, during a period when there is no insertion signal SI, the video signal SV from the terminal 11 is supplied to the A / D converter 13 through the switch circuit 12, and is A / D converted from an analog signal to a digital signal. The / D-converted video signal SV is supplied to a video signal compression circuit 14 and is compressed into a signal SC by a predetermined compression algorithm. The compressed signal SC is supplied to an addition circuit 15. Note that the above-mentioned DCT, AD
PCM, ADRC, etc. can be used.

In the period TI of the insertion signal SI, the video signal SV (= insertion signal SI) from the terminal 11 is supplied to the delay circuit 16 through the switch circuit 12 and the time delay of the signal SV in the compression circuit 14 After being delayed by a corresponding time, it is supplied to the adder circuit 15.

Thus, as shown in FIG. 2C, a video signal SA in which the compressed video signal SC and the uncompressed insertion signal SI are combined is extracted from the adder circuit 15.

The signal SA from the adding circuit 15
Is supplied to a recording processing circuit 17, in which processing for recording such as addition of an error correction code and conversion to a format corresponding to a recording medium is performed.
The processed recording signal SR is supplied to a recording head 18 and recorded on a recording medium 19, for example, a magneto-optical disk 19.

FIG. 3 shows a reproducing apparatus 30 corresponding to the recording apparatus 10 of FIG. That is, in the synchronizing signal forming circuit 41, standard horizontal and vertical synchronizing signals are taken out, these synchronizing signals are supplied to the servo circuit 42 as reference signals, and the output of the servo circuit 42 is
And the disk 19 is rotated at a predetermined speed. Further, the synchronization signal from the forming circuit 41 is supplied to the timing signal forming circuit 44, and the insertion signal S
It becomes “L” during the period TI of I and becomes “H” during other non-insertion periods.
Is formed, and this signal ST is supplied to the switch circuit 33 as a control signal.

The signal SR recorded on the disk 19 is reproduced by a reproducing head 31, and the reproduced signal SR is supplied to a reproduction processing circuit 32, where error correction and the like are performed and the original added signal SA is reproduced. Is played.

During the period when there is no insertion signal SI, the reproduction signal SA (= signal SC) from the processing circuit 32 is passed through the switch circuit 33 to the video signal decompression circuit 34 which performs the decompression processing complementary to the compression circuit 14. To reproduce the original video signal SV, and this signal SV is supplied to the D / A converter 3
To D / A from digital signal to analog signal
The converted and D / A converted video signal SV is supplied to the adding circuit 36.

During the period TI of the insertion signal SI, the reproduction signal SA (= SI) from the processing circuit 32 is supplied to the delay circuit 37 through the switch circuit 33, and the expansion circuit 34
Are supplied to the adder circuit 36 after being delayed by a time corresponding to the time delay of the signal SV at. Further, the synchronizing signal from the forming circuit 41 is also supplied to the adding circuit 36.

In this way, the original video signal SV having the insertion signal SI and to which the synchronizing signal is added is synthesized and extracted from the adding circuit 36, and this video signal SV is output to the terminal 38.

As described above, the video signal SV is compressed and recorded and reproduced. In this case, in particular, according to the above-described apparatus, the insertion signal SI in the vertical flyback period is recorded and reproduced in an uncompressed state. Therefore, the waveform of the reproduced insertion signal SI does not deteriorate, and the insertion signal SI can be used effectively.

In addition, the configuration for this is simple, and no special circuit or expensive device is required.

FIG. 4 shows another embodiment of the recording apparatus 10. In this apparatus 10, instead of the delay circuit 16 of the recording apparatus 10 of FIG. 1, a compression circuit for the insertion signal SI which does not use vertical correlation is used. 24 is provided. 5 corresponds to the recording apparatus 10 of FIG. 4 except that an expansion circuit 39 for performing expansion processing complementary to the compression circuit 24 is provided instead of the delay circuit 37.

According to these devices, since the insertion signal SI is also compressed and recorded / reproduced, the compression ratio as a whole is improved, and the insertion signal SI is provided by a dedicated circuit which does not use vertical correlation. Since compression and decompression are performed, the waveform of the insertion signal SI does not deteriorate.

In the above description, the switch circuit 12
Converts the signal SV (SI) into the A / D converter 13
And to the delay circuit 16, but the signal SV
(SI) is always supplied to the circuits 13 and 16, and the signal SC from the compression circuit 14 and the signal SI from the delay circuit 16 are output.
Can be selectively supplied to the recording processing circuit 17. In this regard, the same applies to the playback device 30.

In the above description, the medium 19 is a magneto-optical disk, but may be another medium such as a magnetic tape or a signal transmission line.

[0025]

According to the present invention, when the video signal SV is compressed and recorded and reproduced on the medium 19, the video signal SV is compressed and recorded / reproduced by a method suitable for the video signal SV, and the vertical return is performed. The insertion signal SI in the line period is
Since recording and reproduction are performed in a non-compressed state or by a compression method suitable for the insertion signal SI, deterioration of the waveform of the reproduced insertion signal SI can be easily avoided.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a recording apparatus according to the present invention.

FIG. 2 is a waveform chart for explaining the operation of the device of FIG. 1;

FIG. 3 is a system diagram showing one embodiment of a reproducing apparatus according to the present invention.

FIG. 4 is a system diagram showing another embodiment of the recording apparatus according to the present invention.

FIG. 5 is a system diagram showing another embodiment of the reproducing apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Recording device, 11 ... Input terminal, 12 ... Switch circuit, 14 ... Video signal compression circuit, 17 ... Recording processing circuit, 1
8 Recording head, 19 Medium, 22 Timing signal formation circuit, 30 Reproduction device, 31 Reproduction head, 32 Reproduction processing circuit, 34 Video signal expansion circuit, 38 Output terminal, 44 Timing signal formation circuit , SI ... insertion signal,
SV: Video signal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/91-5/956 H04N 9/79-9/898 H04N 7/08-7/088 H04N 7 / 24-7/68

Claims (4)

(57) [Claims] A first supply unit for supplying a video signal; a second supply unit for supplying a sub-signal inserted during a vertical blanking period of the video signal; A compression circuit for performing a predetermined compression process using a vertical correlation on a video signal to be converted, a synthesis signal for synthesizing and outputting the sub-signal supplied from the second supply means and the video signal compressed by the compression circuit And a video signal processing device having a circuit. 2. A video signal processing apparatus according to claim 1, wherein the sub-signal supplied from said second supply means to said synthesis circuit is compressed by a compression method different from the compression method of said compression circuit. A video signal processing device having another compression circuit. 3. A supply means for supplying a signal in which a video signal compressed by a compression method using vertical correlation and a sub-signal inserted in a vertical blanking period of the compressed video signal are combined. A separation circuit that separates the compressed video signal and the sub-signal from the synthesized signal; a decompression circuit that decompresses the compressed video signal output from the demultiplexer; and a decompression circuit that decompresses the decompressed video signal. A video signal processing device comprising: an insertion circuit for inserting the sub-signal separated by the separation circuit during a vertical blanking period. 4. The video signal processing device according to claim 3, wherein the sub-signal in the synthesized signal is a signal compressed by a compression method different from the compressed video signal, and A video signal processing device having the compressed sub-signal extracted from the circuit and having another expansion circuit for expanding the extracted sub-signal.