JPH06101855B2 - Video signal converter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal conversion device, and more particularly to a component signal obtained as a result of temporarily separating an input composite video signal into component signals and performing a predetermined signal processing. It is applied to a video signal processing device which obtains an output composite video signal by synthesizing.

[Background technology and its problems]

As a video signal processing apparatus of this kind, for example, as shown in FIG. 1, a decoder unit 2 for transmitting and recording an input video signal to a video tape recorder (VTR) 1 as a video signal processing system, and an output from a reproduced video signal of a VTR 1 A device having an encoder unit 3 for obtaining a video signal has been proposed.

In this case, the decoder section 2 receives the input composite video signal S1 to be recorded in the VTR1 and receives this composite video signal S1.
The component color signal composed of the color difference signals R-Y and B-Y forming S1 is separated into the luminance signal Y, which is encoded and then recorded in the VTR1 as three component signals. The VTR1 records the luminance signal Y diagonally by one field on the first track formed on the tape, compresses the color difference signals RY and BY for one field respectively for 1/2 hour, and then The two signals are time-sequentially arranged and obliquely recorded on the second track, and thus the luminance signal Y and the color difference signals RY and BY are separately recorded as component signals. The VTR 1 reproduces each component signal in the reproduction mode, divides the reproduction color difference signal and doubles it, and thus reproduces the reproduction luminance signal Y and the reproduction color difference signals RY and BY from the reference synchronization signal SYNC and the reference subcarrier. Send with SC. The encoder unit 3 thus reproduces the reproduced color difference signals RY and BY from the VTR 1.
Further, the color signal C is formed from the reference subcarrier SC and the color signal C is combined with the reproduction luminance signal Y and the reference synchronization signal SYNC to obtain the output composite video signal S2.

Thus, in the VTR1, the input composite video signal S1
Component recording has advantages such as high-quality recording and reproduction processing and common recording of video signals of television systems in the world, but there are still problems to be solved.

As one of the problems, once the color difference signals RY and BY separated from the input composite video signal are decoded by the decoder unit 2 and converted into a DC signal format, the decoded color difference signal is converted into a reference sub signal by the encoder unit 3. Since the color difference signals RY and BY of the AC signal format are reconverted using the carrier wave, the phase relationship between the luminance signal Y after encoding and the subcarrier of the chrominance signal is the same as before decoding. The phase relationship between the luminance signal Y and the subcarrier of the color signal C does not become the same,
Therefore, the color frame before decoding cannot be reproduced. If this is left unattended, a color shift occurs in the image obtained based on the encoded composite video signal such that the coloring position of the color signal with respect to the luminance signal Y is displaced. Further, in the worst case, for example, the phase of the band portion including the fine portion of the luminance signal Y becomes opposite in phase to the subcarrier of the chrominance signal, resulting in image distortion such that the information of the fine portion is destroyed. become.

Incidentally, for example, in a video signal of the NTSC system, the luminance signal Y and the chrominance signal C are assigned to different frequency bands by interleaving, but the frequency band of the chrominance signal C is adjacent to the edge of the frequency band component of the luminance signal Y. It has a frequency distribution that overlaps the edges of the components. Therefore, if the luminance signal Y of the video signal is separated from the color signal C by, for example, a comb filter, the overlapping portion remains in the luminance signal Y or the color signal C separated into the components, so that the component signals are combined. It is considered that the composite signal can be obtained without shifting the color frame based on the information indicating the phase relationship of the color subcarrier SC with respect to the luminance signal Y when the composite signal is obtained.

However, as described above, the color signal C of the composite signal is separated from the luminance signal Y, and the color difference signals RY, B- of the DC signal format are separated.
If it is decoded into Y, the information representing the phase relationship between the color subcarrier SC and the luminance signal Y included in the above-mentioned overlapping portion is lost, and the decoded color difference signals RY and BY have Will not be included.

[Object of the Invention]

The present invention has been made in consideration of the above points. When the component composite color signal is once decoded from the input composite video signal and the output composite video signal is encoded after the predetermined processing, the encoded color signal is encoded. It is intended to prevent the phase relationship between the color subcarrier of the signal and the luminance signal from deviating.

[Outline of Invention]

In order to achieve such an object, in the present invention, when a component color signal once decoded is encoded by a reference subcarrier and synthesized with a luminance signal, reference color frame information is formed based on this reference subcarrier. The luminance signal and the component color signal are delayed by a predetermined amount so as to match the input color frame information and the reference color frame information according to the comparison result.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings. The first embodiment is applied to the case of processing a video signal of the NTSC television system, and the decoder unit 2 and the encoder unit 3 of FIG. 1 have the configurations of FIGS. 2 and 3.

That is, the decoder unit 2 receives the input composite video signal S1 coming to the input terminal T0 in the luminance signal-color signal separation circuit 11. The separation circuit 11 separates the color signal S11 including the burst signal and the color difference signal from the input video signal S1 as a composite signal including the luminance signal Y and the color signal C and the synchronizing signal SYNC to separate the color signal S11. And the luminance decode signal S12 including the remaining luminance signal and synchronization signal is sent to the output terminal T1 as the first component signal of the decoder section 2.

The color signal decoding circuit 12 uses the color difference signal R- of the color signal S11.
DC signal format decoding RY corresponding to Y and BY
The color difference signal S13 and the BY color difference signal S14 are generated, the decoded RY color difference signal S13 is directly sent to the output terminal T2 as the second component signal, and the decoded BY color difference signal S14 is given to the addition circuit 13. , And outputs the addition output to the output terminal T3 as the third component signal. In addition to this, the color signal decoding circuit 12 takes out the subcarrier of the color signal S11 (having the phase of the burst signal) and supplies the decoded subcarrier S15 thus obtained to the color frame detection circuit 14.

On the other hand, the vertical synchronizing signal included in the decoded luminance signal S12 of the separating circuit 11 is taken out by the synchronizing separating circuit 15, and the decoded vertical synchronizing signal S16 thus obtained is given to the color frame detecting circuit 14. The color frame detection circuit 14 matches the decode subcarrier S15 with the decode vertical sync signal S16 and generates a vertical sync signal S16, and the relationship between the phase and the phase of the subcarrier (for example, the subcarrier at the rising time of the vertical sync signal S16). Phase) to detect the color frame of the sub-carrier in each field section of the input video signal S1 (in the case of the NTSC system, the first to fourth color frames are sequentially repeated), and the first and second phases are detected.
Of the color frame detection signal S17 (FIG. 4 (A)) that has a positive DC level in the field section of the color frame and has a negative DC level in the field sections of the third and fourth color frames. Send to.

Further, the decode vertical synchronizing signal S16 of the sync separation circuit 15 is given to the timing signal generating circuit 17, and the timing signal generating circuit 17 delays by a predetermined time (for example, 15H) from the generation time (that is, the rising time) of the vertical synchronization signal of each field. At that time, a relatively narrow timing pulse S18 (for example, about 40 [μsec]) is generated at the same period V as the vertical synchronizing signal (FIG. 4 (B)). The timing pulse S18 is given to the multiplication circuit 16 and is multiplied by the color frame detection signal S17. Accordingly, the multiplication circuit 16 converts the timing pulse S18 arriving in the field section of the first and second color frames in which the color frame detection signal S17 is at a positive DC level into a pulse rising in the positive direction, and The timing pulse S18 that arrives in the field sections of the third and fourth color frames in which the detection signal S17 is at the negative DC level is converted into a pulse falling in the negative direction, and this is converted into a color frame inspection signal S19 (Fig. 4). (C)) is given to the adder circuit 13.

Thus, in the adder circuit 13, at the time of the 15th hour in each field with respect to the BY color difference signal S14 coming from the color signal decoding circuit 12, a color frame check representing a color frame in the corresponding field interval of the input video signal S1. The signal S19 is inserted, and this is sent out from the output terminal T3 as the third component signal.

In the decoding circuit 2 having the above configuration, the input video signal
The luminance signal and the horizontal and vertical synchronizing signals of S1 are separated and decoded by the separating circuit 11 as the first component signal and sent to the output terminal T1. Further, the RY and BY color difference signals S13 and S14 arriving in the respective vertical synchronization sections are separated and decoded, and the decoded RY color difference signal S13 is sent to the output terminal T2 as the second component signal and is also decoded. A third method in which a color frame check signal S19 representing the color frame of the field is inserted in the vertical blanking interval of each field of the BY color difference signal S14.
Component signal is sent to the output terminal T3.

These first, second and third component signals S12, S13, S1
4 is recorded in VTR1 as a video signal processing system as described above with reference to FIG. In this case, the decoded luminance signal S12 that is the first component signal is recorded in the luminance signal track one field at a time. Also, a decode BY having a decode RY color difference signal S13 and a color frame check signal S19 which are the second and third component signals.
The chrominance signal S14 is compressed by one field for 1/2 hour and then recorded so as to be continuous in time series with the chrominance signal track adjacent to the luminance signal track. In this way, each component signal recorded in the VTR is simultaneously reproduced for each field and sent to the encoder section 3. In this reproduction mode, the VTR 1 is adapted to servo the luminance signal of one frame (2 fields) based on the reference synchronizing signal, and accordingly the first to third component signals S12 to S14 are also adjacent to each other. The signal for the field is reproduced as a unit. Therefore, the third reproduction component B-
Color frame check signal S1 inserted in Y color difference signal
9 is reproduced in units of two fields of a pair of positive pulses corresponding to the first and second color frames or a pair of negative pulses corresponding to the third and fourth color frames.

The encoder unit 3 receives the reproduction component luminance signal S31 received from the signal processing system 2 at the input terminal T11. A controllable delay circuit 31 and a delay circuit 32 are applied to a combiner circuit 33 having an adder configuration. In addition, the encoder unit 3 is a reproduction component RY received at the input terminals T12 and T13.
Color difference signal S32 and reproduction component BY color difference signal S33
Is similarly applied to the color signal encoder 34 through the controllable delay circuit 31 described above. Further, the encoder unit 3 gives the reference subcarrier S34 given from the VTR1 to the color signal encoder 34 through the input terminal T14. Here, T _SC represents the cycle of the subcarrier of the input video signal S1, and the reference subcarrier S34 has the same cycle T.
Selected to have _SC .

Thus, the color signal encoder 34 reproduces the DC signal format R-
The Y and BY color difference signals S32 and S33 and the reference subcarrier S34 are used to form AC signal type RY and BY color difference signals, and both signals are combined to encode the encoded color signal S35. This is given to the synthesis circuit 33.

Further, the encoder section 3 gives the reference synchronizing signal S36 received from the VTR1 to the input terminal T15 to the combining circuit 33 via the delay circuit 35. Here, the generation timings of the encoded luminance signal S31 and the reference synchronization signal S36 with respect to the encoded chrominance signal S35 are modified by the delay circuits 32 and 35.
From 33, the composite output video signal S2 of the NTSC television system is obtained from the output terminal T16.

By the way, in order to match the encoded output video signal S2 obtained by the above configuration with the color frame of the input video signal S1 given to the decoder section 2, the encoder section 3 is provided with the following configuration. That is, the reference subcarrier S34 and the reference synchronization signal S36 coming from the VTR1 are received by the color frame detection circuit 36, and the relationship between the generation timing of the vertical synchronization signal included in the reference synchronization signal S36 and the phase of the reference subcarrier S34 (that is, vertical synchronization The color frame of the reference subcarrier S34 in each field is detected from the phase of the reference subcarrier at the time of rising of the signal), and the thus obtained reference subcarrier color frame detection signal S37 is applied to the color frame condition determination circuit 37.

On the other hand, of the delay output signals S38, S39, S40 obtained at the output side of the controllable delay circuit 31 corresponding to the reproduction luminance signal S31, the reproduction RY color difference signal S32, and the reproduction BY color difference signal S33, respectively.
A signal S40 corresponding to the reproduced BY color difference signal S33 is given to the color frame inspection signal detection circuit 38, and the code of the color frame inspection signal S19 inserted in each field section of the reproduced BY color difference signal S33. The color frame information is read based on the above, and the read signal S41 is given to the color frame condition judging circuit 37 to judge whether or not the contents match the contents of the reference subcarrier color frame detection signal S37. The color frame condition discrimination circuit 37 uses the discrimination signal S42.
To the controllable delay circuit 31 as a control signal, and when a match is determined, the controllable delay circuit 31 is not delayed and the first to third reproduction component signals S31 to S33 are directly output as output signals S38 to S40. When the discrepancy is detected, the controllable delay circuit 31 is delayed to output the first to third reproduction component signals S31 to S33. And output as output signals S38 to S40. Thus, the color frames of the reproduced RY and BY color difference signals S32 and S33 sent from the delay circuit 31 to the color signal encoder 34 are controlled so as to match the color frame of the reference subcarrier S34 with respect to the reference synchronization signal S36. .

Incidentally, the pulse sign of the color frame inspection signal S19 inserted in the reproduced RY color difference signal S32 is positive (or negative) and represents the first and second (or third and fourth) color frames. If the signals of the third and fourth color frames (or the first and second color frames) arrive as the reference subcarrier S34 at the timing when the reproduced color difference signals S32 and S33 arrive, the discriminating circuit 37 detects a mismatch. Therefore, the delay circuit 31 Only the reproduction color difference signals S32 and S33 are delayed together with the reproduction luminance signal S31. On the other hand, if the pulse code of the color frame inspection signal S19 inserted in the reproduced color difference signal S33 matches the color frame of the reference subcarrier, the determination circuit 37 determines this and the delay circuit 31 is newly added. Keep the state as it is without delay operation.

Thus, the output signal S39 input to the color signal encoder 34
And S40 will be maintained in a state of being coincident with the color frame of the reference subcarrier S34, which means that the composite output video signal S2 having a color frame constrained to an externally provided reference signal during reproduction.
Is obtained from the synthesizing circuit 33.

As described above, according to the configurations of FIGS. 2 and 3, after the component signals S12, S13, S14 separated and decoded from the composite input video signal S1 in the decoder unit 2 are processed in the video signal processing system 1, the encoder unit In order to obtain the composite output video signal S2 by synthesizing and encoding the reproduction component signals S31, S32, S33 in 3,
It is possible to prevent occurrence of color misregistration that may occur due to color frame misregistration in the encoded composite output video signal S2. Therefore, in particular, in the configuration of FIG. 3, the reproduction luminance signal S31, the reproduction color difference signals S32 and S3 are matched so as to match the color frame determined by the reference synchronization signal S36 and the reference subcarrier S34.
By controlling the color frame according to the three phases, it is possible to obtain the composite output video signal S2 having the color frame constrained to the reference signal given from the outside. Further, since the color frames of the reproduction color difference signals S32 and S33 are controlled for each luminance signal frame, the continuity of the color frames of the reproduction color signal is disturbed because, for example, insert editing is performed in the VTR1 as the video signal processing system. 1 "" 2 "" 1 "" 2 "
Even if the reproduced color signals of the color frames in the order of "3", "4", ... Are reproduced, it is possible to surely obtain the composite video signal corresponding thereto.

FIGS. 5 and 6 show another embodiment in which the present invention is applied to the case of processing a video signal of the PAL television system, and the same reference numerals are given to the portions corresponding to those in FIGS. 2 and 3. And show it. In the case of the PAL method, the subcarrier is arranged to repeat the first to eighth color frames, and the phase of the subcarrier in the fifth to eighth color frames is different from the phase of the subcarrier in the first to fourth color frames. Are offset by 180 °. Further, the line alternate relationship of the RY color difference signals in the first to fourth color frames and the fifth to eighth color frames has the same aspect. That is, the line alternations of the first and second color frame sets and the third and fourth color frame sets are different from each other, and the fifth and sixth color frame sets and the seventh and eighth color frame sets are different from each other. The line alternations of the frame sets are different from each other (in contrast, the line alternations of the first and second color frame sets and the fifth and sixth color frame sets are equal to each other, and the third and third color frame sets are equal to each other. The line alternations of the four color frame sets and the seventh and eighth color frame sets are equal to each other).

Incidentally, in the case of the PAL system, the phase of the subcarrier of one of the RY color difference signal and the BY color difference signal (that is, the RY color difference signal) is inverted every line, and the number of lines of the luminance frame is Since the odd number (that is, 625 lines) is selected, the phase mode of the sub-carrier of the RY color difference signal is switched every two fields (that is, one luminance frame) (this is called line alternate of the RY color difference signal). ) Thus, the line alternate of the RY color difference signal is switched every two color frames.

In this way, the PAL system is different from the NTSC system in that the line alternate of the RY color difference signal is switched every two fields. Therefore, in order to match the color frame of the composite output video signal S2 of the encoder unit 3 with the color frame of the composite input video signal S1 of the decoder unit 2, the line alternation relationship is determined by the color signals in the encoder unit 3 and the decoder unit 2. It is necessary to match the color signals in the decoder section 2 and the reference color signals.

In order to achieve such a function, in the decoder unit 2 of FIG. 5, the subcarrier S15 is obtained in the color signal decoder 12, the line alternate signal S51 is obtained from the phase of the RY color difference signal S13, and the sync separation circuit 11 is obtained. The phase of the subcarrier at the timing of generation of the given vertical sync signal of the composite sync signal S12 and the line alternate signal S5
Based on the contents of 1, the color frame detection circuit 14 detects a color frame which is positive in the first to fourth color frames and negative in the fifth to eighth color frames as shown in FIG. 7 (A). Obtain the signal S17. Further, in the timing signal generating circuit 17, for each field, for example, a timing pulse S18 having a relatively narrow width (for example, about 40 [μsec]) is provided at a time position of 12H from the vertical synchronizing signal.
(FIG. 7 (B)) is generated, and this is multiplied by the color frame detection signal S17 in the multiplication circuit 16.

Thus, at the output terminal of the multiplication circuit 16, a color frame inspection signal S19 (FIG. 7 (FIG. 7 (see FIG. 7 (b) is formed), which is composed of positive pulses corresponding to the first to fourth color frames and negative pulses corresponding to the fifth to eighth color frames. C)) is obtained, and this is the addition circuit 1
At 3, it is inserted into the decoded color difference signal S14.

In the case of this embodiment, the color frame detection circuit 14 uses the line alternate signal S5 whose sign is inverted every two fields.
The rectangular wave signal rising at the first and fifth fields is obtained by 1 as shown in FIG. 7 (D), and the signal level of the subcarrier S15 is latched by the rising of the rectangular wave signal, so that FIG. The color frame information S17 shown in FIG. With this configuration, the phase of the subcarrier S15 can be determined with a relatively simple configuration. Incidentally, the phase of the subcarrier S15 may be directly detected as in the case of the color frame detection circuit 14 of FIG. 2, but in the case of the PAL system However, it is inevitable that the phase detection will be performed with high accuracy and the overall configuration will be complicated. However, the configuration of this embodiment can effectively solve this problem.

The other points are similar to those described above regarding the decoder unit 2 in FIG. 2, and the first component signal composed of the decoded luminance signal S12 and the second component signal composed of the RY decoded color difference signal S13 are outputted from the decoder unit 2. And a third component signal obtained by inserting the color frame check signal S19 into the BY decoded color difference signal S14 are recorded in the VTR1 as a video signal processing system.

The VTR1 is composed of a series of four frames (that is, the first to fourth, fifth to eighth color frames) as a unit so as not to break the relationship between the recorded luminance signal Y and the line alternate. Play the component signal (this is 4
Field framing). Also in this case VTR1
The servo is applied in units of the luminance signal of one frame (two fields).

Reference sync signal S36 and reference subcarrier S sent from VTR1
An external reference signal S51 including 34 is supplied to the 4-field framing detection circuit 51 via the terminal T17 of the encoder section 3, and the detection signal S52 is supplied to the 4-field lock determination circuit 52. On the other hand, playback B-played back from VTR1
The sign of each pulse of the color frame detection signal S19 inserted in the Y color difference signal S33 is detected by the detection signal detection circuit 38, and the detection signal S41 is given to the field lock determination circuit 52. The discriminating circuit 52 compares the detection signals S52 and S41, and when there is a deviation of 2 fields between the signals, the servo drive signal S53 is sent to the reproducing servo system of the VTR1 via the terminal T18 and the lock point of this servo system is determined. By advancing (or delaying) by 2 fields, it becomes a 4 field lock state.

In this way, when the VTR1 is reproducing in the four-field locking state, the line alternate detection circuit 53 which receives the detection signal S52 of the four-field framing detection circuit 51 detects the line alternation in each field and outputs the detection signal S54 to 8 It is applied to the field framing detection circuit 54. Here, the 8-field framing detection circuit 54 is based on the phase of the reference subcarrier S34 at the generation timing of the vertical synchronization signal of the reference synchronization signal S36 and the contents of the line alternate detection signal S54, and the first to fourth color frames thereof. At 8 and negative at the fifth to eighth color frames, an eight-field lock detection signal S55 is obtained, and this detection signal S55 is sent to the color frame condition determination circuit 37. In this embodiment, the 8-field framing detection circuit 54 has the same structure as the color frame detection circuit 14 of FIG.

At this time, the color frame inspection signal S41 obtained from the reproduced BY color difference signal S33 is the 8-field lock detection signal S55 (see FIG. 8 (Fig. 8 ( It is locked so that there is no phase shift as shown in FIG. 8 (B) with respect to (A)), or it is locked at a phase shift of 180 ° as shown in FIG. 8 (C). . Therefore, the color frame condition discrimination circuit 37 sends a shift signal S42 to the controllable delay circuit 31 when there is a phase shift of 180 ° to reproduce the reproduction luminance signal S.
31, playback RY color difference signal S32, playback BY color difference signal S33 The color frame of the reference subcarrier S34 with respect to the color frame reference sync signal S36 of the color signal supplied to the color signal encoder 34.

Accordingly, the composite circuit 33 can encode the composite output video signal S2 having a color frame that matches the color frame determined by the reference synchronization signal S36 and the reference subcarrier S34.

As described above, according to the configurations shown in FIGS. 5 and 6, even when the composite input video signal S1 of the PAL television system is decoded into the component signal and the signal processing is performed, the composite output video signal S2 is also encoded. A composite video signal having a color frame constrained to a reference signal given by can be easily obtained.

In doing so, as shown in FIG. 6, a four-field framing detection circuit 51 and a four-field locking discrimination circuit 52 are provided.
After controlling the playback servo system of the VTR1 to the 4-field lock state, the playback color difference signals S32, S33 and the playback luminance signal S
By controlling the phase of 31 to obtain the 8 field lock state, the response operation at the time of mode conversion is further improved as compared with the case where the 8 field lock is realized by using the 8 field servo system first. You can speed it up. Secondly, the color frame of the reproduced color difference signal is "1" or "2".
"3""4""1""2""3""4""5""6"
Even in the case of discontinuity such as "7", "8", and "1" (which may occur when insert editing is performed in VTR1, for example), color framing can be reliably performed. By the way, if an 8-field servo is used, locking may not be possible, but if the structure shown in FIG. 6 is used, it will continue in units of 4 fields, so there is no risk. In this way, thirdly, four-field editing can be easily performed.

Further, in the above-described embodiment, the color frame check signal S19 is inserted into the BY color difference signal S14 in the decoder unit 2 and recorded in the color signal track in the VTR 1, but instead, the color frame check signal S19 is recorded. Alternatively, S19 may be independently transmitted without being inserted in the color difference signal and recorded in the VTR 1, for example, in the time code track.

Further, in the above description, the RY signal and the B signal are used as color difference signals.
The case where the -Y signal is used has been described, but instead of this, I
You may make it use a signal and a Q signal.

〔The invention's effect〕

As described above, according to the present invention, the component color signal is separated from the color subcarrier included in the input composite video signal, and once the baseband component color signal having no color frame information is formed, The phase relationship between the component color signal and the reference color subcarrier is reproduced in the same color frame state as the color frame information of the input composite video signal by using the delay control means. The carrier wave can be replaced with an externally provided reference color sub-carrier wave as needed without causing image distortion and color shift in the image.

In addition, by delaying the luminance signal and the component color signal by a predetermined amount so that the phase of the reference color subcarrier matches the phase of the input color subcarrier with respect to the input component color signal, the component color signal and the reference color subcarrier are delayed. The phase relationship with the carrier wave can be easily matched with the phase relationship of the original composite signal, and the composite output video signal corresponding to the reference signal can be easily combined without causing image distortion and color shift. .

Therefore, there is an advantage that a video signal of the television system in the world can be used as a common composite output video signal of high image quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a video signal processing device,
2 and 3 show a video signal converter according to the present invention.
A block diagram showing a decoder unit and an encoder unit when applied to the processing of an NTSC television system video signal, FIG. 4 is a signal waveform diagram for explaining the operation, and FIGS. 5 and 6 are video signals according to the present invention. Block diagrams showing a decoder section and an encoder section when the signal conversion apparatus is applied to the processing of a video signal of the PAL television system, FIGS. 7 and 8 are signal waveform charts for explaining the operation. 1 ... VTR, 2 ... decoder, 3 ... encoder, 1
1 ... Luminance signal-color difference signal separation circuit, 12 ... Color signal decoding circuit, 14 ... Color frame detection circuit, 15 ... Synchronous separation circuit, 17 ... Timing signal detection circuit, 31 ... Controllable delay circuit, 33 …… Synthesis circuit, 34 …… Color signal encoder, 36 …… Color frame detection circuit, 37 …… Color frame condition determination circuit, 38 …… Color frame check signal detection circuit, 39 …… Controllable delay circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-111196 (JP, A) JP-A-57-121391 (JP, A) JP-A-52-36920 (JP, A) JP-A-55- 26781 (JP, A) JP-A-54-14118 (JP, A) JP-B-51-11888 (JP, B1)

Claims (1)

[Claims] 1. An input composite video signal is separated into a luminance signal and a carrier chrominance signal, and the carrier chrominance signal is divided by a color subcarrier of the carrier chrominance signal into a base having no color subcarrier and color frame information. A first conversion unit that decodes into a component color signal which is a band color signal, detects color frame information of the input composite video signal, and outputs the color frame information together with the component color signal, and a reference color subcarrier. Then, the component color signal is encoded into the carrier color signal, the encoded carrier color signal and the luminance signal are combined to form an output composite video signal, and a reference color frame is generated based on the reference color subcarrier. Information is formed and compared with the input color frame information, and the comparison output is used to perform the encoding process. Second, delaying the luminance signal and the component color signal by a predetermined amount so that the phase of the reference color subcarrier with respect to the component color signal matches the phase of the color subcarrier with respect to the component color signal at the time of decoding. A video signal conversion device, comprising: