JPH08102911A - Video signal processing unit - Google Patents

Abstract

PURPOSE: To keep the period of a video signal and an audio signal in an optimum state independently of various signal paths by giving the audio signal in pairs with the video signal to a variable delay means so as to set a delay time to be a processing time of a selected video signal processing path. CONSTITUTION: When an aspect ratio of a reproduced video signal VPIN reproduced by a digital VTR 1 is changed and outputted as a TV signal, a video signal processing mode control circuit 4 selects a passing path of a video signal, video signal processing circuit 3A-input terminal P1-video signal processing circuit 3B-input terminal P5 by using switching signals S1, S2. An audio delay time control circuit 6 specifies a signal selected by the signals S1, S2 and gives a control signal S3 to a variable audio delay circuit 5 to provide a delay time of t1 +t5 as its delay time. Thus, the period of the video image and the audio signal outputted from the circuit 3B and the circuit 5 is maintained. Thus, the period of the audio signal and the video signal is always kept to be an optimum state independently of a difference from the video processing time according to the selected mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing apparatus, which can be applied to, for example, a video tape recorder.

[0002]

2. Description of the Related Art Today, video tape recorders handle not only analog video signals but also various digital video signals. Further, the video tape recorder has many built-in functions so that the user can select it appropriately. Therefore, the video tape recorder is provided with a plurality of signal processing paths so as to be compatible with the input / output signal format and the combination of selected functions. For example, in addition to a signal processing path when simultaneously recording a video signal and an audio signal, a signal processing path when simultaneously reproducing a video signal and an audio signal, one of the video signal and the audio signal is reproduced while the other is reproduced. A signal processing path for recording is prepared.

[0003]

However, if the signal processing paths are different, the signal processing is also different, so that the processing time varies depending on the paths. Particularly in the case of a video signal, the amount of generated information is large, so that the processing time required for the processing path of the video signal becomes longer than the processing time of the audio signal. Therefore, it is conceivable to synchronize the video signal and the audio signal (lip sync) by delaying the audio signal by the average processing time required for the processing path of the video signal. However, since it is an average value to the last, there is a problem that the movement of the mouth of the person on the screen and the sound are deviated due to the deviation of the output timing of the video and the sound depending on the signal path, and the viewer feels uncomfortable. In order to solve this, it is necessary to insert an audio delay circuit that gives an appropriate delay time to the video signal for each processing circuit of each signal path, but if this is done, the circuit becomes complicated and large in size. There was a problem.

The present invention has been made in consideration of the above points, and is provided with a function capable of maintaining synchronization between a video signal and an audio signal regardless of various signal paths by adding a relatively simple circuit. The present invention is intended to propose a video signal processing device capable of obtaining a video signal.

[0005]

In order to solve such a problem, in the present invention, the processing time (t1) required for signal processing is
+ T4), (t1 + t5), (t2 + t4), (t2 +
t5), (t3 + t4), and (t3 + t5) are different from each other in the plurality of video signal processing paths (2A-3A) and (2A-).
3B), (2B-3A), (2B-3B), (2C-3)
A), (2C-3B), in a video signal processing device for processing a video signal on a video signal processing path selected by selecting an operation mode among the plurality of video signal processing paths, the video signal processing device A variable delay means (5) for delaying and outputting an audio signal forming a variable time and a control means for setting the delay time of the variable delay means (5) based on the signal processing time of the selected video signal processing path ( 6) and are provided.

[0006]

By inputting the audio signal paired with the video signal to the variable delay means (5) and setting the delay time of the variable delay means to the time required for signal processing of the selected video signal processing path, It is possible to match the signal output timing with the audio signal output timing. Since the delay time of the audio signal can be managed at one place in this way, the same effect can be realized with a circuit size significantly smaller than that in the case where a unique delay circuit is provided for each video signal processing path.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 1 generally indicates a digital video tape recorder. The digital video tape recorder 1 has a plurality of video processing circuits 2A and 2A.
B, 2C and 3A, 3B are built in, switch S
The processing path can be freely selected by switching W1 and SW3.

The video processing circuit 2A is a circuit for returning the reproduced video signal V _PIN reproduced from the magnetic tape to the original frame image by performing deshuffling or the like, and the signal processing is performed after a lapse of time t1 from the signal input. The video signal is output to the input terminal P1 of the switch SW1.
The video processing circuit 2B is a circuit for outputting the analog recording video signal V _RIN1 input from the external input terminal by analog digital conversion or the like. After the time t2 has elapsed from the signal input, the signal processed video signal is switched to the switch SW1. It is arranged to output to the input terminal P2.

Further, the video processing circuit 2C is a circuit for outputting the digital recording video signal V _RIN2 input from the external input terminal by performing shuffling or the like, and time t3 from the signal input.
After the passage of, the signal-processed video signal is output to the input terminal P3 of the switch SW1. The switch SW1 is switched and controlled by the video signal processing mode control circuit 4, and the video signal input to the input terminal Pi (i = 1, 2 or 3) selected by the switching signal S1 is output from the output terminal. The video signal processing circuits 3A and 3B are output.

Here, the video signal processing circuit 3A is a circuit for applying noise reduction processing to the input video signal and outputting it. After a lapse of time t4 from the signal input, the signal processed video signal is switched to the switch SW3. The input terminal P4 is output. Also, the video signal processing circuit 3
B converts the aspect ratio of the input video signal, and outputs the signal-processed video signal to the input terminal P5 of the switch SW3 after a lapse of time t5 from the signal input.

The switch SW3 is switch-controlled by a switch signal S2 provided from the video signal processing mode control circuit 4, and outputs the output video signal V _OUT designated by the switch signal S2 to a recording system or an external output terminal. Has been done. By switching these switches SW1 and SW3, 3 ways x 2
You can select the street signal path.

On the other hand, the reproduction audio signal A _PIN , the analog recording audio signal A _RIN1 and the digital recording audio signal A _RIN2 which form a pair with each video signal are input terminals P1 and P of the switch SW2.
2 and P3 so that the audio signal corresponding to the input terminal Pi (i = 1, 2 or 3) selected by the switching signal S1 is output from the output terminal to the variable audio delay circuit 5 in the subsequent stage. Has been done.

The variable voice delay circuit 5 is a first-in first-out memory (hereinafter referred to as a FIFO (First in First Out) memory), delays a voice signal by a time designated by a control signal S3, and outputs it as an output voice signal A _OUT. It is designed to output. At this time, the audio delay time control circuit 6 sets the command value of the control signal S3 as follows. That is, the voice delay time control circuit 6 selects the switching signal S for selecting the signal path.
1 and S2 are input, and the time ti (i = 1, 2 or 3) required for processing the video signal processing circuit 2x (x = A, B or C) on the selected path and the video signal processing circuit 3x ( x
= Time tj (j = 4 or 5) required for processing A = B)
The command value of the control signal S3 is set so as to delay the audio signal by the sum (ti + tj) of

An example of setting the audio delay time associated with the selection of the signal path in the above configuration will be described. First, the reproduced video signal V _PIN reproduced by the digital video tape recorder 1
A case will be described in which the aspect ratio is changed to output the television signal. At this time, the video signal processing mode control circuit 4 selects the video signal processing circuit 3A-input terminal P1-video signal processing circuit 3B-input terminal P5 as the passage path of the video signal by the switching signals S1 and S2.

The audio delay time control circuit 6 specifies the signal path selected from the switching signals S1 and S2, and applies the control signal S3 to the variable audio delay circuit 5 so that the delay time of t1 + t5 is applied to the variable audio delay circuit 5. . As a result, the synchronization between the video and the audio output from the video signal processing circuit 3B and the variable audio delay circuit 5 can be maintained. This result is the same when other signal paths are selected.

According to the above configuration, the function capable of always keeping the synchronization between the audio and the video in the optimum state regardless of the difference in the video processing time depending on the selected mode is made possible by adding the simple configuration. It is possible to realize a digital video tape recorder.

In the above embodiment, the case where the audio signal is not passed through any audio signal processing circuit has been described, but the present invention is not limited to this, and the reproduced audio signal A _PIN and the analog recording audio signal A _{RIN1 are provided.} The present invention can be widely applied to the case where signal processing is performed through dedicated audio signal processing circuits corresponding to the above. In this case, the delay time of the audio signal processing circuit may be set by adding the delay time of the audio signal processing circuit to the delay time of the video signal processing circuit.

Further, in the above-described embodiment, the case where the delay time of the audio signal is adjusted according to the signal path has been described, but the present invention is not limited to this, and the signal processing of the audio signal and the video signal becomes slow. The other delay time may be adjusted according to the one.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the signal processing circuit of the digital video tape recorder has been described, but the present invention is not limited to this, and the recording for recording the video signal and the audio signal on the disk-shaped recording medium is carried out. It can also be applied to a reproducing apparatus for reproducing a video signal and an audio signal from a device or a disk-shaped recording medium. In addition to these, it can be similarly applied to a signal processing circuit of a television receiver, an editing machine, or the like.

[0021]

As described above, according to the present invention, the audio signal forming a pair with the video signal is input to the variable delay means regardless of the selection of the video signal processing circuit system, and the delay time of the variable delay means is changed. By setting the time required for signal processing of each selected video signal processing circuit system, the video signal output timing can be matched with the audio signal output timing by adding a small-scale circuit. The device can be easily obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a video signal processing device according to the present invention.

[Explanation of symbols]

1 ... Digital video tape recorder, 2A, 2B,
2C, 3A, 3B ... Video signal processing circuit, 4 ... Video signal processing mode control circuit, 5 ... Variable audio delay circuit, 6 ...
... Voice delay time control circuit.

Claims (2)

[Claims] 1. A video signal processing path having a plurality of video signal processing paths each having a different processing time, and the video signal processing path selected by the operation mode selection among the plurality of video signal processing paths. In the video signal processing device for processing the signal, a variable delay means for delaying and outputting an audio signal paired with the video signal for an arbitrary time, and the variable based on the signal processing time of the selected video signal processing path. A video signal processing device, comprising: a control unit that sets a delay time of the delay unit. 2. A plurality of audio signal processing paths each having a different processing time required for signal processing, and a signal processing time of an audio signal processing path selected by selecting the operation mode among the plurality of audio signal processing paths. 2. The video signal processing device according to claim 1, further comprising a correction unit that corrects the delay time set by the control unit.