JPH07118184B2 - Video signal recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a video signal recording / reproducing apparatus for simultaneously recording and reproducing a digitized video signal and a time code signal.

[Outline of Invention]

According to the present invention, in a video signal recording / reproducing apparatus which records and reproduces a time code signal at the same time as a digitized video signal, the input time code signal is delayed by the time required for recording / reproducing signal processing of the digital video signal and recorded. As a result, during reproduction, the time correspondence between the reproduction time code signal and the reproduction-signal-processed digital video signal is matched.

[Conventional technology]

In VTRs (video tape recorders) for broadcasting stations or professionals, so-called time code signals, which are tape position information or address information, are recorded at the same time as the video signals (video signals), and the time code signals are tape-edited. It is generally used for setting edit points during work.

Here, in the case of the conventional analog VTR, there is no time delay of 1 μs in the reproduction circuit system of the video signal, and the timing adjustment with the time code signal is easy. Moreover, when a so-called TBC (time base collector) is used to correct a time base error such as jitter, a delay of about several H occurs in the video signal, and even if a digital TBC is used,
It is about 6H. Therefore, with this time delay, by advancing with respect to the reference signal (for example, by using an advance sync) and extracting the signal from the tape, a reproduction output via the TBC can be obtained without time delay with respect to the reference signal. Therefore, the reproduced video signal can be output at the same timing as the time code signal.

[Problems to be solved by the invention]

On the other hand, in the case of a digital VTR that digitizes and records a video signal, by adding digital signal processing such as shuffling processing and error correction processing during recording and reproduction of the digital video signal, On the other hand, it is delayed by 100H or more, and the phase of the playback time code signal is also shifted by this amount. On the other hand, as a standard, the time code signal is required to match the predetermined phase of the reference signal, but the playback video signal also needs to be output in synchronization with the phase of the reference signal. If the signal is matched with the reference signal, the time code signal is out of the standard. Therefore, the reproduced video signal is output after being delayed by, for example, one frame.
As a result, a time difference of one frame or more occurs between the reproduction output of the time code signal and the reproduction output of the video signal recorded at the same time, the screen and the time code do not match, and a problem occurs during editing.

The present invention has been made in view of the above circumstances, and the reproduction output digital video signal and the time code reproduction signal have the same relationship, that is, the input video signal and the input time code signal at the time of recording. It is an object of the present invention to provide a video signal recording / reproducing device having the same relationship.

[Means for solving problems]

In order to solve the above-mentioned problems, a video signal recording / reproducing apparatus according to the present invention is a video signal recording / reproducing apparatus for recording / reproducing a time code signal as address information together with a digitized video signal. A delay means for delaying the time code signal with respect to the input digital video signal by a time corresponding to the delay time in the recording side circuit system and the reproducing side circuit system
The input time code signal is delayed by the delay means and recorded together with the digital video signal subjected to the recording signal processing.

[Action]

At the time of recording the signal on the tape, the time code signal which has been reproduced is subjected to the digital reproduction signal processing by delaying the time code signal in advance with respect to the input digital video signal by the time required for the digital signal processing of the recording and reproduction. It is obtained at the same phase and timing as the video signal.

〔Example〕

FIG. 1 is a block circuit diagram schematically showing a video signal recording / reproducing apparatus according to an embodiment of the present invention. FIG. 1A shows a recording side circuit system and FIG. 1B shows a reproducing side circuit system. Shows.

First, in FIG. 1A, for example, another VT is connected to the input terminal 1.
A time code reproduction signal obtained by being reproduced from R or the like is inputted, and this signal becomes time code data by the data being read by the time code reading circuit 2, and one of the selection switches 3 is selected. It is sent to the terminal a. The input terminal 4 is supplied with time code data directly input by operating the input key of the data input device, and this data is sent from the changeover switch 3 to the selected terminal b. The time code data signal from the changeover switch 3 is sent to the delay circuit 5 and delayed by a time corresponding to the time required for digital signal processing for recording and reproducing a digital video signal. The output of the delayed time code data from the delay circuit 5 is sent to the time code signal generation circuit 6 to become, for example, a so-called bi-phase modulated time code signal, which is sent to the recording / reproducing head 8 via the recording amplifier 7.

A normal analog video signal is input to the input terminal 11, and this analog video signal is converted into a digital video signal by an AD (analog-digital) converter 12.
This digital video signal is sent to a recording signal processing circuit 13 and subjected to digital signal processing such as so-called shuffling (interleaving) and error correction coding, and then a video recording head 15 of a rotary head device via a recording amplifier 14.
Sent to.

Next, in the reproduction side circuit system of FIG. 1B, the reproduction time code signal from the recording / reproducing head 8 for time code is taken out from the output terminal 23 via the reproduction amplifier 22.

The reproduced digital video signal from the video reproducing head 31 of the rotary head device is reproduced by the reproducing signal processing circuit 33 via the reproducing amplifier 32.
Then, digital signal processing such as error correction decoding and restoration of so-called shuffling, that is, deshuffling is performed. An output digital signal from the reproduction signal processing circuit 33 is sent to a DA (digital-analog) converter 35 via a delay circuit 34 to be converted into an analog video signal, and then taken out from an output terminal 36. Here, the delay time of the delay circuit 5 corresponds to the delay time in the recording-side circuit system and the reproducing-side circuit system, but the delay in the analog circuit can be almost ignored. The delay time in the side circuit system is the processing time in the recording signal processing circuit 13, the time difference between the recording timing and the reproducing timing of each head 15, 31, the processing time in the reproducing signal processing circuit, and the delay circuit 34. Will be determined by the delay time at.

A signal delay operation in the video signal recording / reproducing apparatus having the above-mentioned configuration as a main part will be described with reference to the time chart of FIG. Here, A in FIG. 2 shows a reference synchronizing signal, and FIGS. 2B to I correspond to the signals at respective points B to I in FIG. 1 and show the frame numbers of the respective signals. .

In FIG. 2, first, the time code input data B synchronized with the phase of the reference synchronization signal A is supplied to the delay circuit 5 of FIG. 1 to be delayed by, for example, one frame, and based on this data. Since the time code signal generation circuit 6 outputs the time code signal in response to the reference sync signal A as shown in FIG. 2C, the time code recording signal sent from the recording amplifier 7 to the recording / reproducing head 8 is 1 The frame is delayed.

The video input signal D from the terminal 11 in FIG. 1 is also synchronized with the reference synchronization signal A. The input video signal D is converted into a digital signal by the AD converter 12 and is digitally processed by the recording signal processing circuit 13, so that a delay of a predetermined time T1 occurs. Therefore, the video recording signal sent to the video recording head 15 via the recording amplifier 14 is delayed by the time T1 with respect to the reference synchronization signal A as shown in FIG. 2E.

Next, on the reproducing side, the reproduction time code signal from the recording / reproducing head 8 shown in FIG. 1 is directly amplified by the reproduction amplifier 22, so that the time code reproduction output signal sent to the output terminal 23 is shown in FIG. 2F. As shown, the reference synchronization signal A is delayed by the one frame.

Next, the reproduction signal of the digital video signal will be described. Depending on the difference in the arrangement angular position between the video recording head 15 and the video reproduction head 31 in the rotary head device, the recording timing and the reproduction timing of the video signal are changed. For example, when the video recording head 15 precedes the video playback head 31 along the rotation direction of the rotary head device, there is a time difference of T2 between them, and the video playback head 15 is played back with a delay of the time T2. Therefore, the video reproduction signal from the video reproduction head 31 is delayed by the time T2 with respect to the video recording signal E as shown in FIG. On the other hand, it is delayed by the time T1 + T2. The video reproduction signal G is sent to the reproduction signal processing circuit 33 via the reproduction amplifier 32 and subjected to digital signal processing in the reproduction signal processing circuit 33, whereby a delay of, for example, time T3 occurs. Therefore, the video reproduction processing signal from the reproduction signal processing circuit 33 is delayed by the time T3 with respect to the video reproduction signal G as shown in FIG. Is delayed by the time T1 + T2 + T3. The video reproduction processing signal H is sent to the output terminal 36 via the delay circuit 34 and the DA converter 35, so that a predetermined delay of, for example, time T4 occurs. For this time T4, the final terminal 36
The delay time in the delay circuit 34 is adjusted so that the video output signal I from the signal is synchronized with the reference synchronization signal A in phase. This is because, as described above, the video signal also needs to be output in synchronization with the phase of the reference signal, so that the frame phase of the video output signal I at the output terminal 36 matches the phase of the reference synchronization signal A. , That is, T1 + T2 + T3 + T4 is just one frame,
The video reproduction processing signal H is delayed by the delay circuit 34. Therefore, the video output signal I delayed by one frame from the reference synchronization signal A is obtained, and the video output signal I and the time code reproduction output signal F are
The timing is completely the same including the phase and the frame number.

In other words, the delay time (1 frame) in the delay circuit 5 on the time code recording side is set equal to the sum of all the delay times (T1 to T4) generated in the video signal recording / reproducing process. , The relationship between the output signals from the terminals 23 and 36 is as follows:
The relationship of each input signal in 11 can be perfectly matched (including timing and frame number).

Note that the present invention is not limited to the above-described embodiment, and for example, it takes a processing time of one frame or more to process the digital signal at the time of recording and reproducing the digital video signal, and the input signal on the recording side is processed. When the final output signal on the reproducing side is obtained with a delay of 2 frames or more, the delay amount of the time code signal on the recording side is set to 2 frames or more so that the relationships of the respective output signals are completely matched. Good.
Further, as the video signal in the above embodiment, not only the video signal but also the audio signal is included, and for example, the audio signal is time-axis compressed and arranged in a predetermined time region in the video signal. May be.

〔The invention's effect〕

According to the video signal recording / reproducing apparatus of the present invention, the discrepancy between the video signal and the time code signal in the final reproduction output signal, which is a drawback of the prior art, is eliminated when the time code signal is recorded. This is resolved by delaying the time code signal in advance by the delay time in the reproduction side circuit system, and the relationship between the final time code reproduction output signal and the video output signal becomes the same as the relationship between the recording side input signals. Can be matched exactly. Therefore, the correspondence relationship between the time code signal and the screen is completely the same, and accurate editing work can be easily realized.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1A is a block circuit diagram showing a schematic configuration of a recording side, FIG. 1B is a block circuit diagram showing a schematic configuration of a reproducing side, and FIG. 3 is a time chart for explaining the signal delay operation in the embodiment. 1 …… Time code signal input terminal 4 …… Time code data input terminal 5 …… Time code delay circuit 6 …… Time code signal generation circuit 8 …… Time code recording / reproducing head 11 …… Video signal input terminal 12 …… AD converter 13 …… Record signal processing circuit 15 …… Video recording head 23 …… Time code signal output terminal 31 …… Video playback head 33 …… Playback signal processing circuit 34 …… Video signal delay circuit 35 …… DA converter 36 …… Video signal output terminal

Claims (1)

[Claims] 1. A video signal recording / reproducing apparatus for recording and reproducing a time code signal as address information together with a digitized video signal, wherein a delay time in a recording side circuit system and a reproducing side circuit system for the digital video signal. Is provided with delay means for delaying the time code signal with respect to the input digital video signal for a time corresponding to, and the input time code signal is delayed by the delay means and recorded together with the digital video signal subjected to the recording signal processing. A video signal recording / reproducing device characterized by: