JPH07114509B2 - Video signal processing method and circuit thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color difference line from a video signal which is simultaneously transmitted with color difference, or a signal having a luminance signal and a color signal corresponding thereto (color signal for simultaneous color difference transmission). The present invention relates to a video signal processing method and circuit for converting into a signal to be sequentially transmitted (color signal for color difference line sequential transmission).

That is, in the NTSC system and the PAL system, which are standard television systems, one set of two types of color difference signals is used in one horizontal cycle (the name is different from the I, Q signals in the NTSC system and the U, V signals in the PAL system). However, both color difference signals RY and BY are simultaneously superimposed and transmitted (this is called simultaneous color difference transmission).

On the other hand, even in the standard system of television as in SECAM system, one of two color difference signals when viewed in each horizontal period, and two horizontal periods that are temporally (spatial) before and after. In some cases, two color difference signals are alternately transmitted, and color difference line sequential transmission is performed.

The present invention converts such a signal for simultaneous color difference transmission into a signal for sequential color difference line transmission, and again converts this signal to a signal for simultaneous color difference transmission. The present invention relates to a method and a circuit for repeating a series of conversions with a signal.

[Prior art]

The conventional iterative conversion between the color difference simultaneous transmission signal and the color difference line sequential transmission signal will be described with reference to FIG.

FIG. 1 (a) shows a number indicating the order of the horizontal period calculated from the vertical synchronizing signal or the signal corresponding thereto in the video signal or the signal corresponding thereto, and n represents the nth horizontal period, and n Has a minimum value of 1 and a maximum value of
It is a positive integer that is 525 in the NTSC system and 625 in the PAL system.

In the following description, in a video signal or a signal corresponding thereto, a luminance signal or a signal corresponding thereto is represented by the number n in FIG. 1A, and in the description below FIG. Description will be given while paying attention to the color difference signal.

FIG. 1 (b) shows a color difference signal (hereinafter, referred to as a first signal) included in each horizontal period in a video signal of color difference simultaneous transmission or a signal corresponding thereto, and Rn in the figure is Nth
The color difference signal component of the color difference signal RY included in the h-th horizontal cycle and Bn indicate the color difference signal component of the color difference signal BY included in the n-th horizontal cycle.

Generally, the method of converting the signals of the color difference simultaneous transmission to the signals of the color difference line sequential transmission is not determined, so that FIG.
Then, from the first signal b of the color difference simultaneous transmission,
A color-difference line-sequential signal c (hereinafter, referred to as the second color-difference signal) when the color-difference signal component of the color-difference signal BY is assigned to the even-numbered horizontal period and the color-difference signal component of the color-difference signal R-Y is assigned to the odd-numbered horizontal period. Signal)).

FIG. 1 (d) shows the second signal c of the above-mentioned color difference line sequential transmission.
2 shows a signal d for simultaneous color difference transmission (hereinafter referred to as a third signal) created from the above, and various methods of creating the third signal d are conceivable. Here, a commonly used method will be described. .

That is, the color difference signal component of the nth horizontal cycle (Rn− ₁ , Bn of the nth horizontal cycle in FIG. 1D) is the color difference of the nth horizontal cycle in the second signal c. Signal component Bn,
It is created by the combination of the color difference signal component Rn- ₁ of the (n-1) th horizontal period, which is one horizontal period earlier in time, and the horizontal period (n-1, n + 1) before and after that is the same as described above. It is created by reversing R and B in the explanation.

Next, the third of the color difference simultaneous transmission obtained in FIG.
The signal d is converted again into the color difference line sequential transmission signal e (hereinafter referred to as the fourth signal) shown in FIG. 6E, and the color difference simultaneous transmission signal f (hereinafter referred to as the fifth signal) is further converted. Consider the case of converting to.

FIG. 1 (e) shows a case where the third signal d is converted into a fourth signal e for color-difference line sequential transmission again. In this case, generally, the conversion method can be arbitrarily selected. Therefore, here, the color difference signal component of the color difference signal R-Y is included in the even-numbered horizontal cycle, and the color difference signal of the color difference signal BY is included in the odd-numbered horizontal cycle. The case where components are assigned is shown.

FIG. 1 (f) shows a case where the fourth signal e is further converted into a fifth signal f for simultaneous color difference transmission,
Although various methods of creating the fifth signal f are conceivable, a method generally used will be described here.

That is, the color difference signal component of the nth horizontal cycle (Rn− ₁ , Bn− ₂ of the nth horizontal cycle in FIG. 2F) is the fourth
Color difference signal component Rn of the n-th horizontal period in the signal e of
_-1 and the nth time that is one horizontal period earlier in time
It is created by the color difference signal component Bn- ₂ of the -1st horizontal cycle, and in the horizontal cycles (n-1, n + 1) before and after that, it is created by combining R and B in the above description in reverse. There is.

In the above description, the conversion process of converting the signal of the color difference simultaneous transmission into the signal of the color difference line sequential transmission and again converting into the signal of the color difference simultaneous transmission is performed twice. As a result, a partial change occurs in the color difference signal component, so the change in the color difference signal component will be described next.

First, comparing the first signal b and the third signal d which are the same color difference simultaneous transmission, the color difference signal component of the nth horizontal period is Rn, Bn in the first signal b. , And the third signal d becomes Rn− ₁ , Bn.

This is because when the first color signal b is converted into the second color signal c, the color difference signal component is halved, and when the third color signal d for simultaneous color difference transmission is created, one horizontal cycle is used. The color difference signal component of the first signal b and the third signal d is theoretically corrected as long as the above-mentioned conversion is performed. It occurs in.

Next, comparing the third signal d and the fifth signal f, which also transmit the same color difference simultaneously, in the third signal d, as described above, the color difference signal component of the nth horizontal cycle is Rn−. _In the fifth signal f, the horizontal period having the same color difference signal component as the first and the second signal f is the (n + 1) th.

That is, this means that every time the conversion process for creating the fifth signal f from the third signal d is repeated, in the example of FIG. 1, the chrominance signal is delayed by one horizontal period with respect to the luminance signal or the signal corresponding thereto. It means that it will be delayed later. That is, this result is a very inconvenient matter because color shift occurs when the process of repeating such conversion process is involved.

[Outline of Invention]

According to a first aspect of the present application, when a color signal for simultaneous color difference transmission is converted into a color signal for sequential color difference line transmission, the first color difference signal of the color signal for simultaneous color difference transmission is compared with an odd-numbered horizontal period of a luminance signal. The second color-difference signal of the color-difference simultaneous transmission color signal is assigned to the even-numbered horizontal period of the luminance signal, and when the conversion opposite to the conversion is performed, the color-difference line sequential transmission color signal of , The horizontal cycle not including the first color difference signal and the horizontal cycle not including the second color difference signal are interpolated using the first and second color difference signals of the horizontal cycles in the vicinity thereof, respectively An object of the present invention is to obtain a video signal processing method capable of reliably preventing a phase shift of a color difference signal with respect to a luminance signal even when inverse conversion is repeatedly performed.

The second invention of the present application provides the first and second color difference signals included in the color signal for simultaneous color difference transmission, wherein the first and second color difference signals are odd-numbered orders of the luminance signal in the video period, and First switching to be assigned for even horizontal periods
Switch means, a color signal for color difference line sequential transmission, and a delay signal thereof, in a horizontal period of the color signal for color difference line sequential transmission that does not include the first and second color difference signals, and a horizontal period in the vicinity thereof. And a second switch means for switching so that the first and second color difference signals are complemented, thereby providing a video signal processing circuit capable of easily realizing the method of the first invention of the present application. To aim.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

Before explaining the embodiments of the present invention, the cause of the delay of the color difference signals as described above will be described.

In the example of FIG. 1, when the second signal c is created from the first signal b, the color difference signals BY are generated in even-numbered horizontal periods.
While the conversion is performed such that the color difference signal R-Y is assigned to the odd-numbered horizontal period, the color difference signal R-Y is generated in the even-numbered horizontal period when the fourth signal e is generated from the third signal d. Y is converted by assigning the color difference signal BY to the odd-numbered horizontal period. That is, the first and second conversions are odd and even, and the first and second conversion methods are different. This causes the delay of the color difference signal.

Therefore, in the video signal processing method according to the first embodiment of the present invention shown in FIG. 2, the first time of deciding the allocation of the color difference signals when the second signal c is created from the first signal b. The conversion method and the second conversion method for determining the assignment of the color difference signals when creating the fourth signal e from the third signal d are the same method. It prevents a delay.

The operation and effect of this embodiment will be described below with reference to FIG.

2 (a) and (b) are respectively FIG. 1 (a),
Since it is the same as (b), the description is omitted here.

2C is the same as that of FIG. 1C as a result, but in the present embodiment, the color difference signal B-Y is applied to the even-numbered horizontal period during conversion to the color difference line sequential transmission. , The color difference signals R-Y are always assigned to the odd-numbered horizontal periods, and this conversion method creates a fourth signal e (FIG. 2 (e)) described later. The same conversion method as the case is different from the conventional example of FIG.

FIG. 2D shows a third color difference simultaneous transmission in the same manner as in the case where the third signal d of FIG. 1D described above is created.
Signal d is generated, and details of the generation method are omitted here.

FIG. 2 (e) shows a signal e (hereinafter referred to as a fourth signal) for color-difference line sequential transmission created from the third signal d shown in FIG. 2 (d). The conversion method in this case is exactly the same as the conversion method for creating the second signal c in FIG. 2 (c). That is, in this example, the color difference signal component of the color difference signal BY is assigned to the even-numbered horizontal periods, and the color difference signal component of the color difference signal R-Y is assigned to the odd-numbered horizontal periods.

FIG. 2 (f) shows a signal f (hereinafter, referred to as a fifth signal) for simultaneous color difference transmission created from the fourth signal e (FIG. 2 (e)). There are various possible methods of creating the signal f, but here, the signal f is created by using a generally used method. For example, the fifth signal f (second
The color difference signal component (Rn−) of the nth horizontal cycle in FIG.
₁ , Bn) is the nth signal in the fourth signal e (FIG. 2 (e)).
It is created by the color difference signal component Bn of the th horizontal cycle and the color difference signal component Rn-1 in the (n-1) th horizontal cycle that is temporally preceding by _one horizontal cycle, and in the horizontal cycles before and after that. Are created by reversing R and B in the above description.

Here, as in the case of FIG. 1, FIG. 2 (d), (f)
Comparing the third signal d and the fifth signal f, which transmit the same color difference simultaneously as shown in FIG.
In the case of this embodiment shown in FIG. 2, these two signals d and f
Have the same color difference signal component (for example, the color difference signal component of the nth horizontal cycle is Rn− ₁ , Bn), and the process of conversion from the third signal d to the fifth signal f is repeated many times. However, the inconvenient result that the color difference signal as in the case of FIG. 1 is delayed by one horizontal period for each conversion with respect to the luminance signal or the signal corresponding thereto does not occur.

This can be seen by comparing FIG. 1 and FIG.
In the case of FIG. 2, the first conversion method from the first signal b to the second signal c shown in FIGS. 2B and 2C,
This is because the second conversion method from the third signal d to the fourth signal e shown in FIGS. 2D and 2E uses the same predetermined method, As a result, as shown in FIGS. 2C and 2E, the second signal c and the fourth signal e have the same color difference signal component in each horizontal synchronization.

In the embodiment shown in FIG. 2, when a signal for color difference line sequential transmission is created from a signal for color difference simultaneous transmission,
The conversion method in which the color difference signals B-Y are assigned to the even-numbered horizontal periods and the color difference signals R-Y are assigned to the odd-numbered horizontal periods has been shown as an example, but the result as shown in FIG. 2 is obtained. Not limited to the case of such an example, instead, conversion may be performed such that the color difference signal BY is assigned to the odd-numbered horizontal cycle and the color difference signal RY is assigned to the even-numbered horizontal cycle. , A different conversion method may be used.

That is, the color signal conversion from the color signal for simultaneous color difference transmission to the color signal for color difference line-sequential transmission is performed regardless of the number of times of conversion, each of the first color difference signals of the color signal for color-difference line sequential transmission. It is only necessary to satisfy the condition that each of the second color difference signals and the second color difference signals are always processed so as to correspond to the same horizontal period of the luminance signal.

Next, the configuration of the video signal processing circuit for realizing the above-mentioned video signal processing method according to the second invention of the present application will be described.

FIG. 3 shows a circuit configuration in the process of conversion from the first signal b to the third signal d shown in FIG. In the figure, 20 is a signal processing unit for converting a signal for simultaneous transmission of color differences into a signal for sequential transmission of color difference lines. In the processing unit 20, 1 is a video signal having a luminance signal and a color signal for simultaneous transmission of color difference. A video input terminal 2 for inputting a video signal is a decoder circuit (DECO) for decoding a video signal into a luminance signal a and a signal for simultaneous color difference transmission (first signal b).
DER), 4 takes out the vertical synchronizing signal and the horizontal synchronizing signal from the luminance signal a, and corresponds to these in FIG. 4 (g).
A sync separation circuit that outputs signals g and h as shown in (h),
Reference numeral 5 is a switch signal generation circuit for generating a control signal i (control signal for conversion processing) as shown in FIG. 4 (i) from these two signals g, h, and the sync separation circuit 4 and the switch signal generation circuit. A control signal generating means is constituted by 5. Reference numeral 3 denotes a switching circuit (conversion circuit) for converting the first signal b into a second signal c. This is a circuit for converting the first signal b in the horizontal synchronization sequence and the color difference line sequence by the control signal i. The second signal c is converted so that it has a predetermined relationship with the order. 6 is a mixing circuit for mixing the second signal c and the luminance signal a. Reference numeral 7 is a transmission path, on which recording, reproduction, transmission, processing and the like are performed.

Contrary to the signal processing unit 20, a signal processing unit 30 converts a color difference line sequential transmission signal into a color difference simultaneous transmission signal. In the signal processing unit 30, 8 is a color difference line sequential transmission signal (first The video signal including the second signal c) and the luminance signal a
Of the second signal c
Is a 1H delay circuit for delaying by 1 horizontal cycle, and 10 is a switching circuit for alternately switching the second signal c output from the separation circuit 8 and the 1H delayed second signal to create a third signal d. , 11 are encoder circuits (ENCODER) for encoding the third signal d and the luminance signal a, and 12 is a video output terminal.

Further, FIG. 5 shows a circuit for generating the control signal i (synchronization separation circuit 4
And a switch signal generating circuit 5). In the figure, 25 is an input terminal, and 26a and 26b detect the edges of the vertical synchronizing signal and the horizontal synchronizing signal extracted by the sync separating circuit 4, respectively. Signals g, h as shown in Fig. 4
27 is a T-flip-flop to which the signal g is applied to the reset (RST) input and the signal h is applied to the clock (T) input, and 28 is an output terminal.

Next, the operation will be described.

A video signal including a color signal simultaneously transmitted with a color difference is input from the video input terminal 1, and the video signal is supplied to the decoder circuit 2 with a luminance signal a (corresponding to FIG. 2A) and a color difference signal b.
(Corresponding to FIG. 2B).

Next, a horizontal sync signal and a vertical sync signal are extracted from the luminance signal a by the sync separation circuit 4. Note that these signals may be extracted from the input video signal.
Then, signals g and h (Figs. 4 (g) and (h)) corresponding to these are generated from the vertical synchronization signal and the horizontal synchronization signal,
The switch signal generation circuit 5 creates a control signal i (FIG. 4 (i)) for the switching circuit 3 from these two signals g and h.

The color difference signal b (first signal b) simultaneously transmitted by the color difference obtained by the decoder circuit 2 is used for the second color difference line sequential transmission by the signal switching circuit 3 by using the control signal i (FIG. 4 (i)). Signal c (FIG. 2 (c)).

At this time, the color difference signal B-Y is assigned to the even-numbered horizontal period, and the color difference signal R-Y is assigned to the odd-numbered horizontal period.

The luminance signal a and the color difference signal (second signal c) thus obtained are frequency-multiplexed or time-division-multiplexed by the mixing circuit 6 and output, and are recorded, reproduced, transmitted, processed, etc. on the transmission line 7. Done.

Next, the signal that has passed through the transmission path 7 (a video signal including a color signal for color-difference line-sequential transmission) is separated into a luminance signal and a color-difference signal by the separation circuit 8, and the luminance signal is input to the encoder circuit 11, which will be described later. The video signal is encoded together with the color difference signal d and output from the video output terminal 12.

On the other hand, regarding the color difference signal, the signal that has passed through the transmission path 7 is input to the separation circuit 8, and thereby the second signal c for color difference line sequential transmission is obtained. And this second signal c
And the second signal c is sent to the 1H delay circuit 9 for one horizontal period (1
H) The delayed signal is alternately switched using the switching circuit 10 to create the third signal d for simultaneous color difference transmission. This third signal d is input to the encoder circuit 11 together with the above-mentioned luminance signal, and the video signal (the third signal in FIG.
Corresponding to the signal of, and is modulated by the color subcarrier).

The process of conversion from the first signal b to the third signal d has been described above. Next, the process of conversion from the third signal d to the fifth signal f will be described.

A signal corresponding to the third signal d output from the video output terminal 12 is input to the video input terminal 1, and the video input signal is decoded by the decoder circuit 2 into a luminance signal a and a color difference signal d. It

Next, the sync separation circuit 4 extracts the horizontal sync signal and the vertical sync signal from the luminance signal a (or the input video signal). And from this vertical sync signal and horizontal sync signal,
The signals g and h (Figs. 4 (g) and (h)) corresponding to these are created, and the two signals are generated by the switch signal generation circuit 5.
A signal i (FIG. 4 (i)) for controlling the switching circuit 3 is created from g and h.

The color difference signal d (third signal d) simultaneously transmitted by the color difference obtained by the decoder circuit 2 is changed from the first signal b to the first signal b by using the control signal i (FIG. 4 (i)) by the switching circuit 3. It is converted into the fourth signal e of the color difference line sequential transmission by the same conversion method as the method of converting the second signal c into the signal c. That is, the color difference signal B-Y is assigned to the even-numbered horizontal period, and the color difference signal R-Y is assigned to the odd-numbered horizontal period.

The luminance signal a and the color difference signal (fourth signal (e)) thus obtained are frequency-multiplexed or time-division-multiplexed by the mixing circuit 6 and output, and are recorded, reproduced and transmitted on the transmission line 7. And so on.

Next, the signal that has passed through the transmission line 7 is separated into a luminance signal and a color difference signal by a separation circuit 8, and the luminance signal is an encoder circuit.
The video signal is input to 11, encoded into a video signal together with a color difference signal f described later, and output from a video output terminal 12.

On the other hand, regarding the color difference signal, the signal that has passed through the transmission path 7 is input to the separation circuit 8, and as a result, the fourth signal e for color difference line sequential transmission is obtained. Then, this fourth signal e
And this 4th signal e is sent to the 1H delay circuit 9 for one horizontal period (1
H) The delayed signal is alternately switched using the switching circuit 10 to create the fifth signal f for simultaneous color difference transmission. The fifth signal f is input to the encoder circuit 11 together with the luminance signal described above, and the video signal (the fifth signal f in FIG.
Corresponding to the signal of, and is modulated with a color subcarrier).

The process of conversion from the third signal d to the fifth signal f has been described above. However, when further conversion is performed below, the process of conversion from the third signal d to the fifth signal f is Repeated.

Next, the operation of the control signal i generating circuit will be described with reference to FIG.

The luminance signal a is input from the input terminal 25, and the sync separation circuit 4
The vertical sync signal and the horizontal sync signal are separated by. Then, the edge of each signal is detected by the differentiating circuits 26a and 26b, and the signals g and h as shown in FIGS.
Is obtained. The signal g is input to the reset (RST) input of the T-flip-flop 27, and the signal h is input to the clock (T) input. Then, a control signal i as shown in FIG. 4 (i) is obtained from the Q output of the T-flip-flop 27.

In this embodiment, when converting the color signals of the color difference simultaneous transmission into the color difference line-sequential signals, the conversion is always performed so that the horizontal cycle order and the color difference line-sequential order have a fixed relationship. Therefore, the color shift does not occur even when the above-mentioned two signals are repeatedly converted for repeated recording and reproduction. Further, in order to obtain the circuit of this embodiment, a simple circuit may be added to the conventional circuit without increasing the cost.

In the above embodiment, the circuit for generating the control signal i has a simple circuit configuration as shown in FIG. 5, but the circuit is not limited to this, and is more stable instead of, for example, a T-flip-flop. A multifunctional counter circuit or the like may be used.

〔The invention's effect〕

As described above, according to the first invention of the present application, when the color signal for simultaneous color difference transmission is converted into the color signal for color difference line-sequential transmission, the first color difference signal of the color signal for simultaneous color difference transmission has an odd order of the luminance signal. The second color difference signal of the color signal for simultaneous color difference transmission is assigned to the even-numbered horizontal cycle of the luminance signal, and the color difference line sequence is assigned when the reverse conversion is performed. A horizontal cycle of the transmission color signal that does not include the first color difference signal and a horizontal cycle that does not include the second color difference signal,
By interpolating using the first and second color difference signals of the horizontal cycle in the vicinity thereof, respectively, even when the above conversion and inverse conversion are repeatedly performed, it is possible to reliably prevent the phase shift of the color difference signal with respect to the luminance signal. It is possible to obtain a video signal processing method capable of

According to the second invention of the present application, the first and second color difference signals included in the color difference simultaneous transmission color signal are converted into the first, second and third color difference signals.
Color difference signal is transmitted to the odd-numbered and even-numbered horizontal periods of the luminance signal in the video period, and the color-difference line sequential transmission color signal and its delay signal are transmitted to the color-difference line sequential transmission. And a second switch means for switching so that the first and second color difference signals in the horizontal cycle in the vicinity of the horizontal cycle in which the first and second color difference signals of the use color signal are not included are supplemented. Therefore, even if the above conversion and inverse conversion are repeated only by adding a simple circuit configuration for controlling the switching of the first and second color difference signals, the phase shift of the color difference signal with respect to the luminance signal can be surely achieved. A video signal processing circuit that can be prevented can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a relation of signal arrangement when video signal processing is performed by a conventional method, and FIG. 2 is a relation of signal arrangement when signal processing is performed by a video signal processing method according to an embodiment of the present invention. FIG. 3 is a configuration diagram of a video signal processing circuit according to an embodiment of the present invention, FIG. 4 (a) is a signal arrangement diagram showing the order of luminance signals, and FIGS. 4 (g) (h) are Waveform diagrams of signals output from the sync separation circuit of the circuit shown in FIG. 3, respectively. FIG. 4 (i) is a waveform diagram of signals output from the switching signal generation circuit of the circuit shown in FIG. 3, and FIG. FIG. 4 is a diagram showing an example of the configuration of a portion related to control signal generation in the circuit shown in FIG. 3. 2 ... Decoder circuit, 3 ... Switching circuit (conversion circuit), 4 ... Sync separation circuit, 5 ... Switch signal generation circuit, 6 ... Mixing circuit. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A chrominance signal included in a video signal together with a luminance signal, a chrominance signal for simultaneous color difference transmission including both first and second chrominance signals for each horizontal period of the luminance signal, and the luminance. A video signal processing method for mutually converting between a color signal for color difference line sequential transmission, which alternately includes one of a first color difference signal and a second color difference signal for each horizontal period of the signal, wherein the color for simultaneous color difference transmission is At the time of conversion from the signal to the color difference line sequential transmission color signal, the first color difference signal of the color difference simultaneous transmission color signal is assigned to the odd-numbered horizontal period of the luminance signal in the video period, and the color difference simultaneous transmission is performed. The second color difference signal of the color signal is assigned to the even-numbered horizontal period of the luminance signal to create the color signal for color difference line sequential transmission, and the color signal for the color difference line sequential transmission is changed to the color signal for simultaneous color difference transmission. For the above-mentioned color difference line sequential transmission during conversion The first and second color difference signals of the neighboring horizontal cycle are interpolated to the even-numbered horizontal cycle that does not include the first color difference signal and the odd-numbered horizontal cycle that does not include the second color difference signal. A video signal processing method, characterized in that a color signal for simultaneous transmission is created. 2. The color difference signals are RY and BY signals.
The video signal processing method according to claim 1, wherein the video signal processing method is a signal. 3. A color signal included in a video signal together with a luminance signal, a color signal for simultaneous color difference transmission including both first and second color difference signals for each horizontal period of the luminance signal, and the luminance. In a video signal processing circuit for mutually converting between a color signal for color difference line sequential transmission including alternately either the first or second color difference signal for each horizontal period of the signal, the video signal processing circuit is separated from the video signal. The color signal for simultaneous color difference transmission, and the first and second color difference signals included in the color signal
First and second switch means for switching the first and second color difference signals so as to be assigned to the odd-numbered and even-numbered horizontal periods of the luminance signal in the video period, and the color-difference line sequential transmission color signal and its delay signal. received,
These signals are the first of the color signals for color difference line sequential transmission.
Second switching means for switching so as to interpolate the first and second color difference signals in the adjacent horizontal cycle to the even-numbered horizontal cycle not including the color difference signal and the odd-numbered horizontal cycle not including the second color difference signal. And a video signal processing circuit.