JP2862570B2 - High-definition television signal mixing switching device - Google Patents

Description

The present invention relates to a method for converting two high-definition television signals, particularly a high-definition television signal encoded by sub-sampling time base compression for band compression transmission, into image quality. The present invention relates to a device for switching between two signals without impairing, such as mixing and wiping (hereinafter simply referred to as “mixing”).

(Summary of the Invention) The present invention relates to an apparatus for mixing and switching MUSE signals, and when mixing and switching between MUSE signals or between MUSE signals and a baseband high-definition television signal, only one signal is used. If not, a switch operation is performed on a signal obtained by decoding the MUSE signal into a baseband signal. If the signal is set to the MUSE signal side, the input MUSE signal is directly output.

Thus, the deterioration of the image quality of the high definition television due to the switch operation is prevented.

(Prior Art) There is no conventional example to be described as this kind of prior art. In other words, a method of mixing and switching baseband high-definition television signals in the form of R, G, and B signals, or two high-definition television signals encoded by subsampling time axis compression for band compression transmission For example, once the MUSE signal is completely decoded,
A method of mixing and switching the G and B signals or the Y (luminance) signal in the form of two color difference signals and then encoding the MUSE signal again is conceivable.

The MUSE signal described here is based on the studio standard 1125.
Book, 60 fields (interlaced), aspect ratio 1
6: 9, Nominal video signal bandwidth R, G and B signals All analog signals encoded by motion-compensated multiplex sub-sample band compression to transmit high-definition television signals of 30 MHz on channels of approximately 8 MHz transmission band Therefore, hereinafter, the present specification will mainly refer to a device for mixing and switching MUSE signals which are high-definition television signals, but the present invention is not limited to this MUSE signal. For details of the MUSE signal, refer to the literature, Ninomiya et al .: MUSE
See Development of Method, NHK Technical Research, Vol. 39, No. 2, pp. 18-53.

(Problem to be Solved by the Invention) When the method described in the section of the related art is adopted, when the image is mixed and switched, the encoding and decoding are repeated every time the video signal passes through the switcher. As a result, image quality degradation occurs.

On the other hand, if the encoded high-definition television signal is directly mixed without being decoded, the image quality deteriorates although it is not fatal from the following points.

If two control signals (eg, 32 bits per field, refer to the above-mentioned document) in the high definition television signal encoded in the MUSE signal do not match, an intermediate control is performed, or one of the two is performed. In this case, control signals are used.

In the case of the MUSE signal, since nonlinear emphasis is used, linear mixing in a strict sense cannot be performed.

For the above reasons, it is desirable to avoid mixing high-definition television signals in the form of MUSE signals as much as possible.
On the other hand, if a transmission path with sufficient bandwidth cannot be secured,
Although material transmission is required, a high-definition television signal whose band has been compressed like a MUSE signal must be used.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to perform a switcher operation in the state of a baseband signal when the switcher operation is not cut off for one signal, and to perform a switcher operation when the switcher operation is not cut off for one signal. Is to provide a method of mixing and switching high-definition television signals by a method that minimizes image quality degradation, such as outputting an encoded signal as it is.

Here, the terms “when one signal is not cut off” and “when one signal is cut off” mean and define the following as used in this specification. I want to be understood. That is, in the case of performing “between two signals such as mixing and wiping two high-definition television signals” described above and below, the mixing ratio of the processing between the two signals is 100% with respect to one of the signals, If the other signal is not mixed (1: 0 or 0: 1), set this to 100
% In the sense that the signal used is cut off, it is defined as "cut off on one signal". Instead, the mixing ratio between the two signals is a: b (where a and b are both (A positive real number that is not zero) is defined as "one signal has not been truncated".

(Means for Solving the Problems) A first invention of a high-definition television signal mixing and switching apparatus described in the present specification for achieving the above-mentioned object is to perform two motion compensation type multiple sub-sample band compression transmission. What is claimed is: 1. A high-definition television signal mixing and switching device comprising a switcher for processing and switching between two encoded high-definition input high-definition television signals, the device comprising: decoding the two input high-definition television signals, respectively; Two decoders for obtaining two baseband high-definition television signals; a switcher for processing and switching between the two decoder output signals; and an encoder after the switcher for encoding the output signals of the switcher; The switcher receives the inter-signal processing 2
If one of the two input high-definition television signals is cut off, the input high-definition television signal of the cut-out side of the two input high-definition television signals is encoded. A switch for passing the signal without passing through the decoder and the switcher; and two input high-definition televisions, the output signal of the switcher and the output signal of the switcher being subjected to the signal processing between the two signals by the switcher. If one of the signals has not been cut off, select the output signal of the switcher, if the switcher has been cut off by the one signal, select the output signal of the switch,
A mixer that mixes these in time series and uses the output as an output signal of the device.

A second invention of a high-definition television signal switching apparatus is a method for converting an input high-definition television signal encoded for motion-compensated multiple sub-sample band compression transmission and a baseband input high-definition television signal between two signals. A high-definition television signal mixing and switching apparatus comprising a switcher for processing and switching, the apparatus comprising: a decoder for decoding the input high-definition television signal to obtain a baseband high-definition television signal;
A switcher that processes and switches between the decoder output signal and the baseband input high-definition television signal between two signals; an encoder after the switcher that encodes an output signal of the switcher; an output signal of the switcher and the encoded signal. Input high-definition television signal
If the switcher has not cut off any one of the output signal of the decoder and the baseband input high definition television signal subjected to the processing between the two signals, and if the switcher cuts off the signal of the one of the two. If the cutoff side is the baseband input high-definition television signal, select the output signal of the switcher, and if the switcher is cutoff to the one signal. If the cut-off side is the output signal of the decoder, select the encoded input high-definition television signal, mix these in chronological order, and compare the output with the output signal of the device. And a mixing device.

(Operation) According to the apparatus of the present invention, when two high-definition television signals are mixed and switched, only the necessary minimum encoding and decoding processes are performed. The processing for band compression transmission can be utilized without deteriorating.

(Embodiment) The mixed switching apparatus of the present invention basically handles decoded R, G, and B signals when one of two high-definition television input signals is not "cut off". In the case of, the encoded high-definition television signal, that is, the MUSE signal is directly output.
In the non-operating period, the MUSE signal is decoded once, achieves the purpose, and then re-encoded.Decoding and encoding are repeated, so that a new deterioration occurs in the output signal. A sufficient image quality can be ensured comprehensively by the output signal.

In order to realize the above-mentioned basic method, the following considerations are required. That is, the signal delay matching between the period of mixing in the R, G, and B forms and the period of outputting the MUSE signal.

Ensuring the continuity of the aforementioned control signals used in the MUSE signal form.

Elimination of shocks such as signal level fluctuations and gradation fluctuations when switching between periods in which R, G, and B signals are mixed and periods in which MUSE signals are output.

An example of a specific method for solving the above problems will be described below.

FIG. 1 shows a block diagram of the entire system according to the first embodiment of the present invention. The signal processing system is handled digitally.

It is assumed that two high-definition television signals are respectively encoded in the MUSE signal form and input to the signal processing system of the mixed switching device of the present invention as the MUSE input (1) and the MUSE input (2). However, it is assumed that both input signals have already been synchronized in phase by a frame synchronizer as preprocessing. These two signals are decoded by the A / D converters 1 and 2 and the decoders 3 and 4, respectively, and become R, G and B signals of the original high-definition television signal, and are mixed and processed by the switcher 5.

While the switcher 5 is operating, that is, while one of the two input signals is not "cut off", the output signal mixed in the form of the R, G, and B signals by the switcher 5 is output to the MUSE encoder. The signal is supplied to the encoder 6 and encoded, and the output is output as the output of the processing system according to the present invention via the mixer 8. Further the switcher 5 is a state of "take-away", "take-away" signal is output (dashed line in the drawing) operates and the switching device S ₁ and S ₂ by the signal, A /
Either one of the output signals of the D converters 1 and 2 is output via the delay unit 7 and the mixer 8 as it is.

However, in the latter case, a preliminary step is required until this state is completely achieved. That is, the switcher 5 is "take-away" ready and "take-away" signal is output from the switcher 5 switcher S ₁ and S ₂
Rests on the "cutting" side.

The control signal generated when the output signal of the switcher 5 is encoded by the encoder 6 into the form of the MUSE signal is:
At this time, it must be matched with the control signal of the MUSE input signal on the "cutting" side. This is to make the connection of the signals smooth when the output signal of the encoder 6 is switched to the "cut off" signal.

Elements that need to be adjusted in the above-described control signal adjustment are basically a sampling phase (sub-sampling phase) and a motion vector. The sub-sampling phase of the chrominance signal is line-sequential, and the mutual relationship remains unchanged only by matching the phase relationship between the two MUSE input signals with a frame synchronizer. It is variable because it is related to the vector. For example, in the case of a MUSE signal, the read address of the memory used for interpolating between frames and between fields is adjusted to the motion vector of the screen in order to prevent a decrease in resolution during operations such as camera pan and tilt. This is because it is fluctuating, for example, by performing a motion correction for shifting. Therefore, a "phase matching" operation is required for the luminance signal.

This "phase matching" method is performed as described above.
That is, the encoder 6 is forcibly operated with a motion vector obtained by a control signal on the MUSE input signal side to be matched, and when a problem occurs in the luminance signal sub-sample phase, the motion vector and the sub-sample phase are compared. In order to match the relative relationship, the motion vector given by the encoder 6 is set to one sample, that is, one field period (the motion vector is one vector / field).
Adjust by adding or subtracting only the line. Only after the above operation is performed, the output signal of the encoder 6 is switched to the MUSE signal on the “cut-off” side.

Also, in such a system, since all signals operate digitally, the gradation and level characteristics should match each other well, so there is little problem when switching, but if you are worried about some deviation, It may be better to prepare a short-term timer 9 after the “cutting” is completed, to perform a cross-fade process in which the processing time is controlled by the timer 9, and to mix in the mixer 8.

Next, FIG. 2 shows a system block diagram of a second embodiment according to the present invention. This embodiment is not a mixed switching between two MUSE signals, but a MUSE signal in which a high-definition television signal is encoded. And a mixed switching device between raw R, G and B signals which are not encoded.

In the blocks of the system diagram shown in FIG. 2, the blocks having the same functions as those of the system shown in FIG. 1 are denoted by the same reference numerals, but as apparent from comparison of both sides, the system shown in FIG.
If the switcher 5 is "cut off" on the raw R, G, and B input signal (digital signal) side of the high-definition television signal, the signal is switched. 5, always output via the encoder 6 and the mixing and cutting device 8.

When the MUSE input signal and the R, G, and B input signals are mixed by the switcher 5, the output signal of the MUSE input signal is mixed with the output signal of this system via the block of the decoder 3, the switcher 5, the encoder 6, and the mixer 8. If the MUSE input signal is switched from this state to "cut off", the same operation as in the first embodiment is required, but the description is omitted.

In the first and second embodiments, the matching of the control signal is also required at the start of the mixing operation of the switcher 5, but this is because the sub-sampling phase of the luminance signal is set in advance to the MUSE input on the "cut off" side. No special considerations are required because it is only necessary to forcibly match the signal.

In the above description, the baseband signals of high-definition television signals have been treated as R, G and B signals, but these may be the luminance signal Y and the two color difference signals RY and BY signals.

Further, in this embodiment, the MUSE signal has been treated as a signal obtained by compressing the motion-compensated multiplex sub-sample band. However, the present invention is not limited to this, and the motion-compensated multi-subsample signal is not limited to this. It is obvious that the present invention can be applied to a high-definition television signal in which multiple sub-sample bands are compressed.

(Effects of the Invention) As described in detail above, according to the apparatus of the present invention, the minimum necessary encoder and the like are required at the time of a switcher operation such as mixing and switching two high-definition television signals.
Since the method that allows the decoder processing is adopted, the object can be achieved without deteriorating the image quality as far as the left, and while keeping the processing for the band compression transmission as it is.

[Brief description of the drawings]

1 and 2 show block diagrams of the first and second embodiments, respectively, of the apparatus of the present invention. 1,2 A / D converter 3,4 Decoder 5 Switcher 6 Encoder 7 Delay unit 8 Mixer 9 Timer 10 D / A converter

Claims (5)

(57) [Claims] 1. A high-definition television signal mixing / switching apparatus comprising a switcher for processing and switching between two input high-definition television signals encoded for two motion-compensated multiplexed sub-sample band compression transmissions. The apparatus comprises: two decoders for respectively decoding the two input high-definition television signals encoded to obtain two high-definition television signals in baseband; and processing the two decoder output signals between the two signals. A switcher for switching; an encoder after the switcher for encoding an output signal of the switcher; and 2 if the switcher has cut off one of two input high-definition television signals subjected to the processing between the two signals. Of the encoded input high definition television signals A switch for passing the input high-definition television signal without being passed through the decoder and the switcher; and an output signal of the switcher and an output signal of the switch between the two signals. The selector selects the output signal of the switcher if one of the two input high-definition television signals to be processed has not been switched to the other, and the switcher has selected the switcher if the switcher has switched to the one of the two signals. Output signals, and mix these in time series,
A high-definition television signal mixing / switching device, comprising: a mixer that uses the output as an output signal of the device. 2. A high-definition switcher for switching between an input high-definition television signal and a baseband input high-definition television signal, which are encoded for motion-compensated multiplex sub-sample band compression transmission, between two signals. A television signal mixing and switching device, comprising: a decoder for decoding the encoded input high definition television signal to obtain a baseband high definition television signal; and a decoder output signal and the baseband input height. A switcher that processes and switches between high-definition television signals between two signals; an encoder after a switcher that encodes an output signal of the switcher; and an output signal of the switcher and the encoded input high-definition television signal, The output of the decoder, wherein the switcher receives the processing between the two signals The signal and the baseband input high-definition television signal are not cut off to one of the signals and the switcher is cut off to the one signal and the cut-off side is the cut-off side. If the input signal is a baseband high-definition television signal, the output signal of the switcher is selected, and if the switcher is cut off by the one signal, the cut off side is the output signal of the decoder. And a mixer for selecting the encoded input high-definition television signals, mixing these in time series, and using the output as an output signal of the apparatus. Television signal mixing switching device. 3. The high-definition television signal mixing and switching device according to claim 1, wherein said encoder after said switcher is an encoder for performing encoding of the same content as said encoding. 4. The apparatus according to claim 3, wherein the processing between the two signals of the switcher is in a cut-off state and the cut-off side is an output signal of the decoder. A high-definition television signal mixing / switching device to which a control signal of a decoder is inputted. 5. The apparatus according to claim 3, wherein the mixer outputs a signal output from an encoder after the switcher, an output signal from the switcher, or the encoded input high-definition television signal after the signal is cut off. A high-definition television signal mixing / switching apparatus, wherein when mixing the signals in a time series, the mixing is performed by cross-fade processing in which the processing time is controlled by a timer.