JPH09224261A - Video signal recording and playback device - Google Patents

Abstract

(57) Abstract: Horizontal and vertical reinforcement signals are surely recorded to improve the quality of a reproduced image and reduce the circuit scale. A second generation EDTV signal is given to a Y separation circuit 41 to separate a luminance signal. Further, the second generation EDTV signal is given to the BPF 42 to separate the color signal band. This color signal band includes HH signals and VT and VH signals in addition to the color signals. The output of the BPF 42 is color demodulated in the demodulation circuit 43, and color difference signals Cr and Cb are obtained. The recording / playback unit 44
The luminance signal Y and the color difference signals Cr and Cb are recorded. At the time of reproduction, the modulation circuit 46 restores the color difference signals Cr and Cb to the original color signals. This color signal includes HH signal and VT and VH signals. The band of the reproduced luminance signal is limited by the LPF 45. The adder 47 adds the luminance signal and the chrominance signal to restore the original signal. Since the comb filter using the frame memory is not adopted, the circuit scale is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal recording / reproducing apparatus suitable for a consumer digital VTR or the like.

[0002]

2. Description of the Related Art In recent years, second-generation EDTV (Extended Definition TV) broadcasting has been started aiming at high image quality and high sound quality. Second-generation EDTV broadcasting is compatible with current broadcasting and has a screen aspect ratio of 1
The horizontal aspect ratio of 6: 9 makes it possible to watch programs with a realistic feel. The effective scanning line of the second generation EDTV signal (wide aspect television signal) is 1 in the vertical center of the current NTSC signal having an aspect ratio of 4: 3.
It corresponds to the part of 6: 9. Therefore, for example, when a second-generation EDTV broadcast is displayed by a television receiver for current broadcasting having an aspect ratio of 4: 3, a letterbox display having a non-image portion at the top and bottom of the screen and a main image portion at the center is displayed. Will be done.

In the second generation EDTV signal, since only the central portion 16: 9 of the current NTSC signal having an aspect ratio of 4: 3 is used as the effective scanning line, the number of effective scanning lines of the current NTSC signal is 480. On the other hand, the number of effective scanning lines of the transmitted second generation EDTV signal is 360. In a television receiver compatible with the second-generation EDTV system, these 360 effective scanning lines are converted into 3 → 4 scanning lines at the time of decoding to return to 480 lines. Since the vertical resolution of the second generation EDTV signal is deteriorated as compared with the current NTSC signal by simply performing the scan line conversion, the vertical reinforcement signal for improving the vertical resolution is multiplexed and transmitted at the time of transmission.

In the second generation EDTV system, a sequential scanning signal of 480 lines / screen height is converted into an interlaced scanning signal and transmitted on the transmitting side. In this case, in order to make the letterbox format, that is, to make the number of effective scanning lines 360, the luminance signal of 480 lines / screen height is band-limited to 360 lines / screen height signal by the vertical low-pass filter. To do. Further, in order to convert to the interlaced scanning signal, the luminance signal is band-limited to the signal of 180 lines / screen height by the vertical low pass filter. The band limitation prevents the generation of aliasing distortion at the time of scanning line conversion. The component YL of 4.2 MHz or less in the horizontal low range of the luminance signal of 180 lines / screen height is transmitted as the main image portion signal. Also, 180 to 3 lost due to band limitation during conversion from progressive scanning to interlaced scanning
A vertical time high frequency component (VT signal) of 60 lines / screen height is transmitted as a vertical reinforcement signal.

The main picture portion signal and the VT signal are SSK
Separated by F (Symmetric Short Kernel Filter). As SSKF, a 3-tap or 5-tap filter is used. Also, the luminance signal vertical high-frequency component (VH signal) of 360 to 480 lines / screen height, which is lost due to band limitation during conversion to the letterbox format, is also transmitted as a vertical reinforcement signal. These components VH and VT are added according to the movement of the image and compressed to 1/3 in the horizontal direction (time direction). In this case, in order to allow the receiving side to separate the VT signal and the VH signal, the VH signal is line-inverted to shift by 15 Hz in the time axis direction, and then the VT signal is obtained.
Add with signal. Next, the added signal is modulated using the color subcarrier, band limited using the Nyquist filter, and multiplexed in the non-image areas at the top and bottom of the screen. In order to prevent the vertical reinforcement signal of the non-image portion from standing out on the screen, a component having a correlation with the VT signal is generated from the main image portion signal, and after subtracting this component from the VT signal, it is converted into the VH signal. It is designed to add.

Further, the component YH in the band of 4.2 to 6 MHz in the horizontal high range of the luminance signal of 180 lines / screen height is multiplexed as a horizontal reinforcement signal HH on the main picture portion signal. In this case, the frequency of the horizontal high frequency component YH is 16
The carrier suppression amplitude modulation is performed using the carrier of / 7fsc (fsc is a color subcarrier frequency), and the frequency is further shifted and frequency-multiplexed with the main picture portion signal.

As described above, in the second generation EDTV signal, the VT and VH signals are multiplexed in the non-picture part and the H-picture is generated in the main picture part.
The H signal is multiplexed and transmitted. That is, of the 525 vertical lines transmitted, the number of effective scanning lines is 480, which is 240 per field, and of the 240 effective scanning lines of each field, horizontal reinforcement is provided in the central 180 main image parts. The signal HH signal is multiplexed. Further, the VT and VH signals of the vertical reinforcement signal are multiplexed in the upper non-picture area having 30 scanning lines and the lower non-picture area having 30 scanning lines in each field. The VT and VH signals are time-compressed to 1/3,
The resolution of the main image portion for three lines is improved by the VT and VH signals multiplexed on one line.

At the beginning of the second-generation EDTV broadcasting, an NTSC television signal having an aspect ratio of 4: 3 and a second-generation EDTV system signal having an aspect ratio of 16: 9 are mixed and broadcast for each program. Expected to occur.
Therefore, it is necessary to perform control corresponding to the NTSC television system and the second generation EDTV system on the receiving side. Therefore, the transmitting side multiplexes and transmits the identification signal indicating that the second generation EDTV system broadcast signal is being transmitted. The identification signal indicates the aspect ratio of the broadcast signal and the presence / absence of various reinforcing signals, and the phase reference for demodulating the reinforcing signal is obtained.

The identification signal is at the top of the image area (22H,
285H) in the horizontal scanning period. The identification signal is
It has bit areas B1 to B27 for 27 bits.
The bit width of each bit is 7 times the color subcarrier period. The bit areas B1 to B5 and B24 are identification codes transmitted in the NRZ (non-return zero) format, and the bit area B6.
To B23 are identification codes of the color subcarrier format (frequency is fsc)
It is. Further, in the bit areas B25 to B27, a confirmation signal for determining the existing video signal is transmitted. The confirmation signal is a sine wave having a frequency of 2.04 MHz (= (4/7) fsc).

By the way, it is conceivable to record or reproduce the second generation EDTV broadcast signal in a consumer VTR (video tape recorder). In this case analog V
If TR is adopted, sufficient resolution cannot be obtained. FIG.
FIG. 1 is a block diagram showing a conventional video signal recording / reproducing apparatus of this type.

Second generation E input via input terminal 1
The DTV signal is supplied to the Y separation circuit 2, the HH separation circuit 3 and the C separation circuit 4. The Y separation circuit 2 and the C separation circuit 4 separate the luminance signal (Y) and the color signal (C) from the second generation EDTV signal. Further, the HH separation circuit 3 separates the HH signal multiplexed in the main picture section. The luminance signal and the HH signal are added by the adder 5 to improve the horizontal resolution of the luminance signal. The output of the adder 5 is FM-modulated by the FM modulation circuit 6. On the other hand, the color signal is supplied to the low frequency conversion circuit 7 and frequency-converted to the low frequency band. The adder 8 adds the FM-modulated luminance signal and the low-frequency-converted color signal, gives the result to the head 9, and records it on the magnetic tape 10.

On the other hand, during reproduction, the information recorded on the magnetic tape 10 is reproduced by the head 11. Playback signal is F
The luminance signal is given to the M demodulation circuit 12 and FM-demodulated.
Further, the color signal is frequency-converted by the frequency conversion circuit 13 and returned to the original frequency band. The demodulated luminance signal and the frequency-converted color signal are added by the adder 14 and output.

As described above, the VT and VH signals are included in the color signal band. At the time of recording, the color signal is frequency-converted after being separated from the luminance signal. Therefore, even if the VT and VH signals included in the color signal band are restored during reproduction, it is difficult to match the time axis with the reproduction luminance signal. For this reason, generally, only a part of the reinforcement signal is decoded and recorded. In FIG. 13, the luminance signal in which the horizontal high range is reinforced by the HH signal is recorded. For example, by adopting an S-VHS VTR having a wide horizontal band, it is possible to improve the horizontal resolution of a wide signal having a horizontally long screen.

However, in the device of FIG. 13, VT, V
The H signal is not used for image reconstruction and cannot improve the vertical resolution. Therefore, the device of FIG. 14 has been developed. The apparatus of FIG. 14 employs a Y / C separation comb type filter 21 and a timing generation circuit 22 in place of the Y separation circuit 2, the HH separation circuit 3 and the C separation circuit 4, and is provided with a TBC (time base collector) circuit 23. 13 is different from the device in FIG.

In FIG. 14, the second generation EDTV signal input through the input terminal 1 is applied to the Y / C separation comb filter 21 and the timing generation circuit 22. The timing generation circuit 22 generates a timing signal indicating the main image portion period and the upper and lower non-image portion period of the input second generation EDTV signal. The Y / C separation comb filter 21 turns on and off the filter operation based on the timing signal. The Y / C separation comb filter 21 separates the luminance signal and the chrominance signal by utilizing the fact that the chrominance signal and the luminance signal have a frequency interleave relationship. During the upper and lower non-image part periods, the Y / C separation comb filter 21 is turned off, and the input signals, that is, the VT and VH signals are allowed to pass through. Further, during the main picture portion period, the Y / C separation comb filter 21 is turned on to separate the luminance signal and the color signal. The Y / C separation comb filter 21 outputs the separated luminance signal and VT, VH signal to the FM modulation circuit 6, and the HH of the color signal and the color signal band is output.
The signal is output to the low frequency conversion circuit 7.

Thus, the Y signal and the VT and VH signals are F
M-modulated and recorded on the magnetic tape 10, color signals and HH
The signal is low-frequency converted and recorded on the magnetic tape 10.

At the time of reproduction, the output of the FM demodulation circuit 12 and the output of the frequency conversion circuit 13 are given to the TBC circuit 23. T
The BC circuit 23 makes the time axes of the input luminance signal, chrominance signal and reinforcement signal coincide with each other and outputs them to the adder 14. Thereby, the horizontal and vertical resolutions of the luminance signal can be improved by using the VT, VH signal and HH signal from the reproduction signal.

As described above, in the apparatus shown in FIG.
The BC circuit 23 suppresses the time variation of the luminance signal, the color signal, and the reinforcement signal, thereby enabling recording and reproduction of the reinforcement signal. However, the color signal band to be recorded is narrow, and the effect of improving the horizontal resolution by the HH signal is not sufficient.

Therefore, it is conceivable to record the second-generation EDTV signal by using a consumer digital VTR adopting high-efficiency coding. FIG. 15 is a block diagram showing a recording system of such a conventional digital video signal recording / reproducing apparatus.

The consumer digital VTR achieves high image quality by high density recording and high efficiency coding. The high-efficiency coding is for coding image data at a low bit rate in order to improve the efficiency of digital transmission and recording. In this high efficiency encoding, m × n
Orthogonal transformation such as DCT (discrete cosine transformation) processing is performed for each block of pixels. Orthogonal transformation is to transform an input sample value into an orthogonal component such as a spatial frequency component. Thereby, a spatial correlation component can be reduced. The orthogonally transformed components are quantized to reduce the redundancy of the signal of the block.

That is, in a general image, the power of the high frequency component of the coefficient after orthogonal transformation is relatively small. Therefore, by quantizing the orthogonal transform coefficient with a predetermined quantization width, the high frequency component of the quantized output becomes almost zero. As a result, the code amount can be reduced. Since the luminance signal and the chrominance signal have different frequency bands, the luminance signal and the chrominance signal are separately encoded in the baseband with high efficiency. Similarly, if the reinforcement signal modulated using the color subcarrier is compressed as it is, the compression rate is reduced. Therefore, a method is used in which the horizontal reinforcement signal (HH signal) is demodulated and added to the luminance signal, and the vertical reinforcement signal is also demodulated and recorded in the luminance signal system.

Second generation E input via input terminal 1
The DTV signal is given to the Y / C separation circuit 31, the vertical reinforcement signal decoder 32, and the identification signal decoder 33. The Y / C separation circuit 31 separates the luminance signal from the color signal and the HH signal,
It outputs to the adder 34 and the horizontal reinforcement signal decoder 35, respectively.
The HH signal is decoded by the horizontal reinforcement signal decoder 35 and added to the luminance signal in the adder 34. As a result, the luminance signal is provided to the recording / reproducing unit 38 with the horizontal high range improved. The color signal from the horizontal reinforcement signal decoder 35 is given to the color decoder 36, subjected to color demodulation and converted into baseband color difference signals Cr and Cb, and then given to the recording / reproducing unit 38.

On the other hand, the vertical reinforcement signal decoder 32 decodes the VT and VH signals multiplexed in the non-picture portion. VT,
The VH signal is supplied to the recording / reproducing section 38 after the DC level is shifted by the DC level shift circuit 37. VT, V
Since the luminance signal is not included in the period in which the H signal is multiplexed, the VT and VH signals can be recorded as independent signals.

The recording / reproducing unit 38 separately processes the luminance signal and the chrominance signal, performs high-efficiency coding, and records the compressed data. Thus, in the recording / reproducing unit 38, the color difference signals Cr,
While Cb is recorded, the luminance signal and the VT and VH signals whose horizontal band has been widened are recorded as luminance signals.

On the reproducing side, the VT and VH signals are modulated with color subcarriers and multiplexed in the non-picture section period. On the other hand, since the horizontal reinforcement signal is combined with the luminance signal during recording, no special processing is performed. That is, since the reproduced signal does not include the HH signal, it is necessary to rewrite the identification code indicating whether or not the HH signal is multiplexed at the time of recording.

The identification signal decoder 33 extracts and decodes the identification signal from the second generation EDTV signal from the input terminal 1. The ID rewriting circuit 39 rewrites the identification code indicating the presence or absence of the HH signal among the decoded identification codes. Also, regarding the error correction code provided for the identification signal,
The CRC rewriting circuit 40 rewrites the auxiliary signal (AU
X) is output to the recording / reproducing unit 38.

As described above, by using the apparatus shown in FIG. 15, it is possible to record the horizontal and vertical reinforcement signals without deteriorating them, and obtain an image with improved horizontal and vertical resolutions from the reproduced signal.

However, the apparatus of FIG. 15 needs to be provided with a decoder necessary for receiving the second generation EDTV, and the circuit scale is extremely large. In particular, since the horizontal reinforcement signal is provided at a position conjugate with the color signal, a comb filter using a frame memory is required to separate the horizontal reinforcement signal, resulting in a huge circuit scale. There was a point.

[0029]

As described above, in the above-described conventional video signal recording / reproducing apparatus, the circuit scale becomes extremely large in order to record and effectively reproduce the horizontal and vertical reinforcement signals. There was a problem.

The present invention has been made in view of the above problems, and provides a video signal recording / reproducing apparatus capable of recording and effectively reproducing horizontal and vertical reinforcement signals and reducing the circuit scale. The purpose is to provide.

[0031]

In the video signal recording / reproducing apparatus according to the present invention, a predetermined identification signal is multiplexed and a vertical reinforcement signal of a color signal band is multiplexed in a non-picture area, and a vertical reinforcement signal in a main picture area is created. First filter means for separating the color signal band by inputting an input video signal based on a wide aspect television signal or a non-wide aspect television signal in which the horizontal reinforcement signal of the color signal band is multiplexed; Second filter means for separating a band which is input and includes at least a band other than the color signal band, and an output of the first filter means are orthogonally demodulated by using a color subcarrier to perform 2
Demodulation means for outputting one demodulation output, narrowband signal recording means for recording the two demodulation outputs, wideband signal recording means for recording the output of the second filter means, and recording by the narrowband signal recording means First reproduction means for reproducing the two demodulated outputs, second reproduction means for reproducing the signal recorded by the wideband signal recording means, and output of the first reproduction means for the color subcarrier. And a third filter for limiting the output band of the second reproducing unit based on the output band of the modulating unit so that the band of the input video signal can be restored by using the modulating unit for orthogonal modulation. Means, and an addition means for restoring the input video signal by adding the output of the modulating means and the output of the third filter means on the time axis.

In the present invention, the color band of the input video signal is separated by the first filter means. Further, the input video signal is separated by the second filter means into a band including at least a band other than the color signal band. When the input video signal is a wide aspect television signal, the output of the first filter means includes the horizontal and vertical reinforcement signal components in addition to the color signal. The output of the second filter means is mainly the luminance signal component. The output of the first filter means is orthogonally demodulated by the demodulation means using the color subcarrier. The output of the second filter means and the output of the demodulation means are recorded by the wide band signal recording means and the narrow band signal recording means, respectively. During reproduction, the output of the first reproducing means is quadrature-modulated by the modulating means, and the output of the second reproducing means is band-limited by the third filter means. The addition means adds the output of the modulation means and the output of the third filter means to restore the input video signal in the entire band.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a video signal recording / reproducing apparatus according to the present invention. This embodiment is composed of a digital circuit.

The second generation EDTV signal is input to the input terminal 1. The frequency spectrum of the second generation EDTV signal is spread over a band of about 4.2 MHz. The main screen period at the center of the vertical direction is 3.58M
The color signal modulated in the Hz band and the horizontal reinforcement signal (HH signal) are included. Also, during the non-image part of the screen top and bottom,
A vertical reinforcement signal (VT signal and VH signal) modulated in the 3.58 MHz band is included.

This second generation EDTV signal is sent to the Y separation circuit 41.
And a band pass filter (hereinafter referred to as BPF) 42. The Y separation circuit 41 is composed of, for example, a 1H (H is a horizontal period) comb filter, separates the luminance signal (Y) from the input second generation EDTV signal, and outputs it to the recording / reproducing unit 44.

The BPF 42 separates the components of the color signal band of about 3 to 4.2 MHz from the input second generation EDTV signal. In this embodiment, the color signals are separated by the BPF 42. Generally, the color signals are separated by a comb filter, but in the present embodiment, they are separated by the BPF 42, and the output of the BPF 42 is not only the color signal but also the HH signal of the color signal band, V
T and VH signals are also included.

The output of the BPF 42 is given to the demodulation circuit 43. The demodulation circuit 43 orthogonally demodulates the input 3.58 MHz band signal using the color subcarrier to obtain baseband color difference signals Cr and Cb. These color difference signals Cr, Cb
Contains the HH signal component and the VT and VH signal components. The output of the demodulation circuit 43 is given to the recording / reproducing unit 44.

The recording / reproducing unit 44 is adapted to magnetically record the input luminance signal and color difference signal on a magnetic tape (not shown) after high efficiency coding, for example. Also, the recording / playback unit
Reference numeral 44 is designed to reproduce the information recorded on the magnetic tape, decode it with high efficiency, and then output it. A signal from the recording / reproducing unit 44 is given to a low pass filter (hereinafter referred to as LPF) 45. Further, the color difference signals Cr and Cb reproduced by the recording / reproducing unit 44 are supplied to the modulation circuit 46.

The modulation circuit 46 receives the input color difference signals Cr and C.
b is modulated with a carrier of 3.58 MHz. As a result, the modulation circuit 46 converts the color difference signal into a signal in the 3.58 MHz band and outputs it to the adder 47. Further, the LPF 45 allows the reproduced signal to pass a low frequency band of about 3 MHz or less and outputs it as a luminance signal to the adder 47. The adder 47 is L
The output of the PF 45 and the output of the modulation circuit 46 are added to restore and output the second generation EDTV signal.

The recording side BPF 42 and the reproducing side LPF 42
Comprehensively with 45, set the reverse characteristic at the cross point. Further, the characteristics of these filters are set so that the band characteristic of the output of the adder 47 becomes flat. Further, since the luminance signal and the chrominance signal pass through a plurality of filters of different systems, it is necessary to design in consideration of the respective group delays. Also, as in the normal NTSC signal processing, It is necessary to match the demodulation and modulation axes of.

Next, the operation of the embodiment thus constructed will be described with reference to the waveform chart of FIG. FIG.
2A shows the second generation EDTV signal input to the input terminal 1, FIG. 2B shows the Y signal from the Y separation circuit 41, and FIG. 2C shows the output of the BPF 42. 2 (d) shows the color difference signal Cr, FIG. 2 (e) shows the color difference signal Cb, FIG. 2 (f) shows the output of the LPF 45, FIG. 2 (g) shows the output of the modulation circuit 46, and FIG. (H) shows the output of the adder 47.

In the present embodiment, the second-generation EDT having a frequency band of approximately DC to 4.2 MHz.
The luminance signal component and the component of the color subcarrier in the 3.58 MHz band of the V signal (FIG. 2A) are divided and processed. That is,
The second generation EDTV signal input through the input terminal 1 is given to the Y separation circuit 41 and the BPF 42. Y separation circuit 41
The luminance signal component shown in FIG. 2B is separated from the second generation EDTV signal by and is given to the recording / reproducing unit 44. It should be noted that when the 1H comb filter is used as the Y separation circuit 41, the luminance signal component of the entire band is separated, and when the LPF is used, the luminance signal component of the low frequency band of about 3 MHz or less is separated and recorded / reproduced. Given to part 44. When the LPF is used as the Y separation circuit 41, the LPF 45 on the reproducing side can be omitted. When a 1H comb-type filter is used as the Y separation circuit 41, luminance signals in the entire band can be recorded. Therefore, when the magnetic tape recorded by the recording / reproducing unit 44 is reproduced by a normal VTR, It is possible to restore the image using the luminance signal of the band. FIG.
(B) shows an example using a 1H comb filter as the Y separation circuit 41.

On the other hand, the BPF 42 separates the color signal band shown in FIG. 2C from the second generation EDTV signal. The output of the BPF 42 is color-demodulated by the demodulation circuit 43, and is output as shown in FIG.
It is converted to the baseband color difference signals Cr and Cb shown in (e). BP without using comb filter for color signal separation
F42 is used, and the color difference signals Cr and C from the demodulation circuit 43 are used.
b includes HH signal components and VT and VH signal components.

The recording / reproducing unit 44 highly efficiently codes the luminance signal Y from the Y separation circuit 41 and the color difference signals Cr and Cb from the demodulation circuit 43 and then records them on the magnetic tape.

At the time of reproduction, the color difference signals Cr and Cb among the reproduction signals from the recording / reproducing unit 44 are given to the modulation circuit 46 and orthogonally modulated by the color subcarrier to restore the color band of about 3 to 4.2 MHz. (FIG. 2 (g)). On the other hand, the luminance signal is L
It is given to PF45 and the luminance signal is about 3M by LPF45.
The low frequency component shown in FIG. 2 (f) is applied to the adder 47 by being restricted to the low frequency range below Hz. The luminance signal component output from the recording / reproducing unit 44 includes components in the entire band from DC to 4.2 MHz, but high frequency components of about 3 MHz or higher are reproduced by the output of the modulation circuit 46. So
Only the component of 3 MHz or less is passed by LPF45. The adder 47 adds the output of the LPF 45 and the output of the modulation circuit 46 to obtain the second generation EDT of the entire band shown in FIG.
Restore the V signal.

As described above, in this embodiment, the luminance signal band and the chrominance signal band are processed separately. BPF without using comb filter in color band separation
Therefore, the color difference signals Cr and Cb obtained by color demodulating the separated color band signals include HH signals, VF and VH signals and their high frequency components. Thus, the recording / playback unit 44
In the above, the luminance signal Y and the HH signal, the VT signal, the VH signal, and the color difference signals Cr and Cb containing the high frequency components thereof can be highly efficiently encoded and recorded. At the time of reproduction, by modulating the color difference signal and adding it to the reproduction luminance signal, HH
The second generation EDTV signal including the signal and the VT and VH signals is restored. That is, the second generation EDTV signal can be recorded by a simple circuit configuration that is substantially the same as the circuit that demodulates the current NTSC signal into the baseband color signal. Also, the second-generation EDT recorded by a simple circuit that is substantially the same as the circuit that obtains the current NTSC signal by modulating the baseband color signal of the current NTSC signal with the color subcarrier.
The V signal can be reproduced and restored. The comb filter using a large-scale frame memory is unnecessary, and the circuit scale can be significantly reduced.

The embodiment of FIG. 1 is a composite NT.
The configuration is almost the same as that of a normal recording / reproducing apparatus for NTSC that demodulates an SC signal into a baseband color signal and records it. Therefore, by sharing the circuit, a recording / reproducing apparatus for the second generation EDTV signal and the NTSC signal can be constructed by adding a few circuits.

FIG. 3 is a block diagram showing an embodiment of a video signal recording / reproducing apparatus capable of recording / reproducing the second generation EDTV signal and the NTSC signal as described above. In FIG. 3, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

This embodiment is different from the embodiment of FIG. 1 in that a comb filter 51, an identification signal detecting circuit 52, a delay circuit 53 and switches S1 and S2 are added.

The second generation EDTV signal or the current NTSC signal is input to the input terminal 1. The BPF 42 separates the color signal band from the input video signal. In this embodiment, the output of the BPF 42 is supplied to the demodulation circuit 43 via the switch S1. Switch S1 has a comb filter
51 outputs are also given. The comb filter 51 separates the color signal from the input video signal.

On the other hand, the input video signal is also supplied to the identification signal detection circuit 52. The identification signal detection circuit 52 detects whether the identification signal is multiplexed on the 22nd and 285th H of the input video signal, and the input video signal is the second generation ED.
It is determined whether it is a TV signal or a current NTSC signal, and the determination result is output to the switch S1.

The switch S1 selects the output of the BPF 42 when the input image signal is the second generation EDTV signal as a result of the determination, and the switch S1 is the NTSC signal when the input video signal is the NTSC signal. The output of the comb filter 51 is selected and output to the demodulation circuit 43.

The luminance signal from the recording / reproducing section 44 is given to the LPF 45 and also to the delay circuit 53. The delay circuit 53 delays the input luminance signal by the signal delay time of the LPF 45. The output of the LPF 45 and the output of the delay circuit 53 are given to the switch S2. The switch S2 selects the output of the LPF 45 when it is shown that the second generation EDTV signal is reproduced based on the data included in the reproduction signal, and when it is shown that the NTSC signal is reproduced. The output of the delay circuit 53 is selected and output to the adder 47.

Next, the operation of the embodiment configured as described above will be described.

Also in this embodiment, the second-generation EDT is used.
The processing for the V signal is similar to that of the embodiment shown in FIG.
Now, it is assumed that the second generation EDTV signal is input through the input terminal 1. The BPF 42 separates the color signal band and outputs it to the switch S1. The identification signal detection circuit 52 detects the identification signal from the input video signal to detect the second generation E signal.
It is determined that the DTV signal has been input. Switch S1
Selects the output of the BPF 42 according to the discrimination result of the identification signal detection circuit 52 and outputs it to the demodulation circuit 43. Thus, in this case, the recording system performs the same recording process as in FIG.

On the other hand, at the time of reproduction, the luminance signal from the recording / reproducing unit 44 is supplied to the LPF 45, band-limited to the low frequency band, and supplied to the switch S2. The switch S2 selects the output of the LPF 45 based on the data contained in the reproduction signal and outputs it to the adder 47. In this way, the reproduction processing similar to that in FIG. 1 is performed also in the reproduction system.

Here, through the input terminal 1, the current NTSC
A signal shall be input. This NTSC signal is applied to the comb filter 51. The comb filter 51 is NTS
The color signal is separated from the C signal and output to the switch S1.
In this case, the identification signal detection circuit 52 outputs the determination result indicating that the NTSC signal is input, and the switch S1 selects the output of the comb filter 51 and outputs it to the demodulation circuit 53. The color signal is color-demodulated by the demodulation circuit 53, and the color difference signals Cr and Cb are given to the recording / reproducing unit 44. Also,
In this case, the Y separation circuit 41 separates the luminance signals in all bands. In this way, processing similar to that of a general recording apparatus for NTSC signals is performed.

At the time of reproduction, the luminance signal from the recording / reproducing unit 44 is given to the switch S2 via the delay circuit 53. The switch S2 selects the output of the delay circuit 53 based on the determination result and outputs it to the adder 47. Further, in this case, the color difference signals Cr and Cb from the recording / reproducing unit 44 are given to the modulation circuit 46 and subjected to color modulation, and then given to the adder 47. In this way, in the reproducing system, the same processing as in a general NTSC signal reproducing apparatus is performed.

As described above, in the present embodiment, it is discriminated whether the input video signal is the second generation EDTV signal or the NTSC signal, and the BPF and the comb-shaped filter are switched to be used. 2nd generation EDTV signal and N
It is possible to obtain a recording / reproducing device compatible with the TSC signal.

In the present embodiment, the BPF and the comb filter are arranged in parallel and the output thereof is selectively used. However, the output of the BPF is given to the comb filter to determine the comb filter. It is obvious that the configuration may be turned on and off based on the result.

FIG. 4 is a block diagram showing an input section of a recording / reproducing section adopted in a video signal recording / reproducing apparatus according to another embodiment of the present invention. Note that FIG. 4 shows only the color signal system of the luminance signal system and the color difference signal system. FIG. 5 is an explanatory diagram showing the correspondence between the second generation EDTV signal and the screen.

As shown in FIG. 5, in the second-generation EDTV signal, the vertical reinforcement signals VT and VH are multiplexed in the non-picture portion period above and below the screen. As described above, V
The T and VH signals are modulated using the color subcarrier,
The phases of the T and VH signals are inverted for each field. Therefore, the non-image part of the image data input in the frame structure is
When the CT process is performed, the power of the high frequency component of the DCT transform coefficient becomes large. Therefore, in the present embodiment, the non-picture portion is converted into the field structure and then compressed.

In FIG. 4, the color difference signal C from the demodulation circuit 43 (see FIG. 1) is applied to the input terminal 61 of the input section 60 of the recording / reproducing section.
r and Cb are input. The color difference signals Cr and Cb are applied to the field compression circuit 62, the frame compression circuit 63, and the motion detection circuit.
64 and the identification signal detection circuit 65. The intra-field compression circuit 62 compresses the input color difference signal for each field and outputs the compressed data to the switch S3. The intra-frame compression circuit 63 compresses the input color difference signal frame by frame and outputs the compressed data to the switch S3.

For example, assuming that the intra-frame compression circuit 63 performs compression processing in block units of 8 pixels × 8 lines in the frame structure, the intra-field compression circuit 62 includes a block of 8 pixels × 4 lines in the first field and a first field. The compression processing is performed on a block of 2 fields of 8 pixels × 4 lines.

The motion detection circuit 64 detects the motion of the image,
The result of motion detection is output to the switch S3. The identification signal detection circuit 65 determines whether the input color difference signal is the second generation EDTV signal or the NTSC signal, and outputs the determination result to the switch S3. The switch S3 is controlled by the result of motion detection and the result of discrimination to select the output of the intra-field compression circuit 62 or the output of the intra-frame compression circuit 63 and output it to the processing circuit of the recording / reproducing unit (not shown). There is.

Next, the operation of the embodiment thus configured will be described with reference to FIG. The solid lines in FIG. 6 indicate odd lines, and the broken lines indicate even lines.

The color difference signal input through the input terminal 61 is applied to the intra-field compression circuit 62 and the intra-frame compression circuit 63 to be subjected to intra-field compression and intra-frame compression, respectively. Now, it is assumed that the color difference signal based on the NTSC signal is input to the input terminal 61. The identification signal detection circuit 65 outputs a determination result indicating that the NTSC signal has been input to the switch S3. As a result, the switch S3 performs the selection operation based on the motion detection result from the motion detection circuit 64.

That is, the switch S3 selects the output of the intra-frame compression circuit 63 when it is determined to be a moving image portion based on the motion detection result, and the switch S3 is set to the inside of the field when it is determined to be a still image. The output of the compression circuit 62 is selected and output.

Here, the input color difference signal is the second generation E
It shall be based on the DTV signal. In this case, the switch S3 switches the selection operation based on not only the motion detection result but also the determination result. That is, in the non-image part period, that is, the period in which the VT and VH signal components are input,
As shown in, the output of the intra-field compression circuit 62 that performs compression with a field configuration of 8 pixels × 4 lines is selected and output. Further, in the main image portion period, as shown in FIG. 6, the output of the intra-frame compression circuit 63 that performs compression with a frame configuration of 8 pixels × 8 lines is selected and output.

As described above, in the present embodiment, the compression is performed in the non-picture portion in the field structure.
The power of the high frequency component of the DCT transform coefficient can be reduced.

By the way, the vertical reinforcement signals VT and VH multiplexed in the non-picture part are 180 to 36 as described above.
The vertical resolution components are 0 lines / screen height and 360 to 480 lines / screen height. Therefore, when the VT and VH signals are DCT-converted, the power of the DCT conversion coefficient is concentrated on the vertical component, unlike a general pattern.

7 to 10 show the intra-field compression circuit 62.
5 is an explanatory diagram for explaining a quantization table of an intra-frame compression circuit 63. FIG. In FIG. 7, the intra-frame compression circuit 63 is N
Area division used for the quantization table at the time of inputting the TSC signal and in the main picture portion period is shown in FIG.
Shows the area division used in the quantization table during NTSC signal input and in the main picture portion period, FIG. 9 shows the area numbers of the quantization table used in the non-picture portion period, and FIG. 10 considers the area number and Q number. It is explanatory drawing which shows the quantization coefficient set by.

FIG. 7 shows area division used in the quantization table when the DCT block has 8 pixels × 8 lines. As shown in FIG. 7, the quantization width is set to increase sequentially from the horizontal and vertical low frequencies to the high frequencies. As a result, the code amount of the quantized output of the high frequency component is reduced.

FIG. 8A shows an odd field of 8 pixels × 4.
FIG. 8B shows a quantization table for lines, and FIG. 8B shows a quantization table for 8 pixels × 4 lines in an even field. As shown in FIGS. 8 (a) and 8 (b), the quantization width is sequentially set larger from the horizontal and vertical low bands to the high bands of each quantization table. As a result, the code amount of the quantized output of the high frequency component is reduced.

By the way, generally, the sampling clock of the color difference signal is different from the sampling clock of the luminance signal. For example, if the sampling clock of the color difference signal has a frequency of 1/4 of the sampling clock of the luminance signal, the size ratio of the luminance block and the color difference block is 1: 4. In this case, a macroblock is composed of 6 DCT blocks including 4 blocks for luminance and 1 block for each color difference, and is used as a unit for encoding.

The code amount of the compressed data differs depending on the pattern, but the code amount can be controlled by changing the setting of the quantization width. In this case, in order to properly allocate the code amount regardless of the pattern, for example, a method is used in which a large block is composed of 5 macroblocks at discrete positions on the screen, and the fixed length is set in large block units. Is adopted. Here, it is necessary to set the quantization coefficient so that the code amount of the macroblock, which is a unit of encoding, is within a predetermined set code amount. Therefore, a number (Q number) considering the generated code amount for each macroblock is set in macroblock units. The smaller Q number is assigned to the macro block in which the generated code amount tends to be larger.

FIG. 9 shows the area numbers assigned to the 8 × 8 DCT transform coefficients suitable for the non-picture area having power in the vertical direction component. In FIG. 10, the transform coefficient is divided into four area numbers 0 to 3 shown in FIG. 9, and each macroblock is divided into 16 stages of Q numbers 0 to 15 and shown. The quantized coefficient for each transform coefficient is obtained from these area number and Q number. In FIG. 10, the quantized coefficients are classified into five levels of 1, 2, 4, 8, and 16.

For example, when the Q number of the belonging macroblock is 4, the quantized coefficient for the transform coefficient belonging to area number 0 is 4, and the quantized coefficient for the transform coefficient belonging to area number 1 is 4, the quantized coefficient for the transform coefficient belonging to the area number 2 is 8, and the quantized coefficient for the transform coefficient belonging to the area number 3 is 8. As shown in FIG. 10, a large quantization coefficient is set from area number 0 to area number 3 for any Q number.

Further, as shown in FIG. 9, the area number increases from the horizontal low band of the 8 × 8 DCT coefficient to the horizontal high band. That is, in the horizontal direction, a large quantization coefficient is set in order from the low band to the high band. The VT and VH signals are set in consideration of the small power of the horizontal high frequency component. On the other hand, as described above, VT, V
The power of the vertical high frequency component of the H signal is large. Therefore, as shown in FIG. 9, the area number is not changed from the vertical low range to the vertical high range. As a result, a sufficient code amount is allocated in the vertical direction from the low band to the high band. In this way, the VT and VH signals can be efficiently compressed by using the quantized coefficients shown in FIGS. 9 and 10.

By the way, a method of fixing the length in units of large blocks is defined in the standard of consumer digital VTRs. According to this standard, recording is performed in sync block units of a predetermined byte length, and macro block data is assigned to each sync block. As described above, the macroblock includes four luminance blocks Y0 to Y3 and one color difference block Cr,
Each sync block has a DCT block recording area for recording data of these 6 blocks. Each DCT block recording area has a DC component area for recording a DC component and an AC component area for recording an AC component. In this case, the low and middle band data of the luminance and chrominance blocks are preferentially allocated to the AC component region of each DCT block recording region, and if the AC component region has a margin, the high band data is also allocated. In addition, this standard has the following rules:

(1) When there is a margin in the unrecorded area of the AC component area, the high frequency components of other DCT blocks that cannot be recorded in the same macroblock are recorded.

(2) Even in the cases of (1), when there is an unrecorded area, the unrecorded high frequency component of the other 4 macroblocks of the large block is recorded.

As described above, in this recording method, with respect to the data in the low and middle frequencies, the position on the screen of the DCT block and the recording position of the sync block correspond to each other. It is possible to reproduce the screen using the effective reproduction data of.

By the way, in the second generation EDTV signal, the luminance signal is not included in the upper and lower non-picture part periods, and the vertical reinforcement signals VT and VH in the color region are multiplexed. Therefore, the amount of compressed data in this period is smaller than that in the main image portion. Therefore, in the present embodiment, the above (1),
In addition to the rule of (2), the recording method is specified.

FIG. 11 is an explanatory diagram for explaining the recording method of the large block compressed data in the present embodiment.

As shown in FIG. 11, the five macroblocks M0 to M4 forming a large block are recorded in five sync blocks. Each sync block has a 6DCT block recording area. The non-image area occupies a quarter of the entire screen. Therefore, at least one macroblock of the non-picture portion is included in the 5 macrobooks that form the large block.
In the example of FIG. 11, the macroblock M0 is a macroblock of the non-picture part, and the macroblocks M1 to M4 are macroblocks of the main picture part.

The macro blocks of the main picture area are recorded in four DCT block recording areas for the luminance blocks Y0 to Y4 and two DCT block recording areas for the color difference blocks Cr and Cb (diagonally shaded left).

The horizontal reinforcement signal HH is multiplexed with the color difference signal in the main picture portion period. Therefore, the color difference data Cr and Cb are recorded in the DCT block recording area for the color difference blocks shown in the shaded area.
It is necessary to record the HH signal component in addition to this, and there are many high frequency components recorded in this portion. On the other hand, the amount of luminance data is extremely small in the non-image portion period.

Therefore, in the present embodiment, the HH signal is prioritized over the high frequency components of the other luminance blocks, and four DCT block recording areas (right diagonal) of the sync blocks for recording the block data of the non-image part are recorded. It is designed to be recorded in the shaded area). Note that VT and VH signals are recorded in the remaining two DCT block recording areas of the sync block that records the block data of the non-image part. As a result, the recording area for the color difference block, the data amount of the main image portion, and H
The recording capacity of the H component can be increased, and the image quality of the reproduced image can be improved.

FIG. 12 is a block diagram showing another embodiment of the present invention. 12, the same components as those of FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

In the embodiment of FIGS. 1 and 3, V
Recording was performed in the state where the T and VH signals were multiplexed with the color difference signals, but like the S-VHS analog VTR shown in FIG.
The VT and VH signals may be multiplexed with the luminance signal and recorded.

The video signal input through the input terminal 1 is supplied to the Y separation circuit 71, the Y comb filter 72, the C comb filter 73, the identification signal detection circuit 52, and the non-image area detection circuit 74. The Y separation circuit 71 is composed of, for example, an LPF and limits the band of the input video signal to switch S4.
Output to The output of the Y separation circuit 71 also includes VT and VH signal components. The Y-comb filter 72 is composed of, for example, a 1H comb filter, and separates the luminance signal component from the input video signal and outputs it to the switch S4.

The C-comb type filter 73 is composed of, for example, a 1H comb-type filter, separates the color signal component from the input video signal, and outputs it to the demodulation circuit 43 via the switch S5. The output of the C-shaped filter 73 also contains the HH signal component. The non-picture portion detection circuit 74 detects the non-picture portion period of the input video signal and outputs a detection signal.

The switches S4 and S5 are the identification signal detection circuit 52.
It operates on the basis of the discrimination result from and the detection signal from the non-image area detection circuit 54. The switch S4 selects the output of the Y separation circuit 71 only during the non-picture part of the second generation EDTV signal, and the Y comb filter 72 at other timings.
Is selected and output to the recording / playback unit 44. Further, the switch S5 is turned off during the non-picture portion of the second generation EDTV signal, and turned on during the other periods, and C
The output of the comb filter 73 is applied to the demodulation circuit 43.

In the reproducing system, the output of the recording / reproducing unit 44 is directly supplied to the adder 47.

Next, the operation of the embodiment thus configured will be described.

Now, assume that the NTSC signal is input through the input terminal 1. In this case, based on the output of the identification signal detection circuit 52 and the output of the non-image area detection circuit 74, the switch S4 outputs the output of the Y-shaped filter 72 to the recording / reproducing section 44.
Switch S5 is turned on and the C-shaped filter
The output of 73 is applied to the demodulation circuit 43. Thus, in this case, a circuit similar to the normal NTSC signal recording circuit is formed.

Next, through the input terminal 1, the second generation EDT
It is assumed that the V signal is input. During the non-image portion period, the switch S5 is turned off and the switch S4 selects the output of the Y separation circuit 71. As a result, the VT and VH signals multiplexed in the non-picture portion period are given to the recording / reproducing unit 44 as a luminance signal system. On the other hand, during the main picture period, the switch S4 selects the output of the Y comb filter 72, the switch S5 is turned on, and the output of the C comb filter is output to the demodulation circuit 43. That is, in this case, the luminance signal separated by the Y comb filter 72 is supplied to the recording / reproducing unit 44, and the color signal and the HH signal separated by the C comb filter 73 are supplied to the demodulation circuit 43.

At the time of reproduction, the luminance signals of the entire band from the recording / reproducing unit 44 are given to the adder 47, and the color difference signals Cr and Cb are color-modulated and then given to the adder 47. In this way, the recording signal is reproduced by a circuit similar to the normal circuit for reproducing the NTSC signal.

As described above, this embodiment has the same effect as that of the embodiment of FIG.
The H signal can be recorded using the luminance signal system.

It is obvious that it is necessary to design in consideration of the group delay due to each filter. Further, since it has a digital configuration, the TBC circuit used in the analog VTR is unnecessary.

[0102]

As described above, according to the present invention, horizontal and vertical reinforcement signals can be recorded and effectively reproduced, and the circuit scale can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a video signal recording / reproducing apparatus according to the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the embodiment.

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a block diagram showing another embodiment of the present invention.

FIG. 5 is an explanatory diagram showing correspondence between a second generation EDTV signal and a screen.

FIG. 6 is an explanatory diagram for explaining intra-field compression and intra-frame compression.

FIG. 7 is an explanatory diagram showing a quantization table.

FIG. 8 is an explanatory diagram showing a quantization table.

FIG. 9 is an explanatory diagram showing area numbers of a quantization table used in a non-picture area period.

FIG. 10 is an explanatory diagram showing a quantization coefficient set in consideration of an area number and a Q number.

FIG. 11 is an explanatory diagram for explaining a recording method of large block compressed data.

FIG. 12 is a block diagram showing another embodiment of the present invention.

FIG. 13 is a block diagram showing a conventional video signal recording / reproducing device.

FIG. 14 is a block diagram showing a conventional video signal recording / reproducing device.

FIG. 15 is a block diagram showing a conventional video signal recording / reproducing apparatus.

[Explanation of symbols]

41 ... Y separation circuit, 42 ... BPF, 43 ... Demodulation circuit, 44 ... Recording / reproducing section, 45 ... LPF, 46 ... Modulation circuit, 47 ... Adder

Claims (5)

[Claims] 1. A wide aspect television in which a predetermined identification signal is multiplexed, a vertical reinforcement signal in a color signal band is multiplexed in a non-picture portion period, and a horizontal reinforcement signal in a color signal band is multiplexed in a main image portion period. First filter means for separating a color signal band by inputting an input video signal based on a signal or a non-wide aspect television signal; and separating a band including at least a band other than the color signal band by inputting the input video signal Second filter means, a demodulation means for quadrature demodulating the output of the first filter means using a color subcarrier to output two demodulated outputs, and a narrowband signal recording for recording the two demodulated outputs. Means, wideband signal recording means for recording the output of the second filter means, and first wideband signal recording means for reproducing the two demodulated outputs recorded by the narrowband signal recording means. Generating means, second reproducing means for reproducing the signal recorded by the wideband signal recording means, modulating means for quadrature modulating the output of the first reproducing means using the color subcarrier, and the input video Third filter means for limiting the band of the output of the second reproducing means based on the output band of the modulating means, so that the band of the signal can be restored, the output of the modulating means and the third The video signal recording / reproducing apparatus, further comprising: an addition unit that restores the input video signal by adding the output of the filter unit to the time axis. 2. A comb filter for separating a color signal band from the input video signal, a discrimination means for discriminating the presence / absence of multiplexing of the horizontal and vertical reinforcement signals, and the input video signal according to the discrimination result of the discrimination means. When it is shown that the horizontal and vertical reinforcement signals are multiplexed, the output of the first filter means is given to the demodulation means, and when it is shown that they are not multiplexed, the first A first switching means for giving the demodulation means the output of the comb filter instead of the output of the first filter means, and the output of the first reproduction means does not include the components of the horizontal and vertical reinforcement signals. In this case, the video signal according to claim 1, further comprising second switching means for giving the output of the second reproducing means to the adding means without passing through the third filter means. Record Recording and playback device. 3. The narrow band signal recording means compresses and records the input demodulation output, and compresses the demodulation output in a field compression mode during the non-image part period. The video signal recording / reproducing apparatus according to claim 1. 4. The narrow band signal recording means is for performing a discrete cosine transform on an input demodulated output to quantize a transform coefficient and compressing and recording, and in the vertical direction of the transform coefficient during the non-image part period. The video signal recording / reproducing apparatus according to claim 1, wherein the quantization coefficient is set so as to transmit the power of the component. 5. The narrow band signal recording means and the wide band signal recording means compress the output of the second filter means and the output of the demodulation means in units of a predetermined macro block, and record compressed data of a plurality of macro blocks. As a unit, a DC component and an AC component of compressed data are recorded in a predetermined recording area of a recording medium by giving priority to middle- and low-frequency data of the AC component over high-frequency data, and the non-image part In the unrecorded area of the predetermined recording area of the recording medium allocated for the macroblock of the period, prioritizing the high frequency component of the luminance component of the compressed data of the macroblock other than the non-image part period,
2. The video signal recording / reproducing apparatus according to claim 1, wherein the color difference components of the compressed data of the macroblocks other than the non-image part period and the high frequency components of the horizontal reinforcement signal component are recorded.