JPH0462508B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a synchronization device for synchronizing and reproducing VTRs of different television standard systems, such as PAL system and NTSC system.

(Prior technology) The NTSC system is the standard television system.
There is a PAL system, but NTSC system VTR and PAL system
There may be cases where you want to synchronize playback with a VTR of the same system.

For example, a digital audio system that digitally records audio signals on magnetic tape using a VTR converts the digitized signal into a pseudo video signal (NTSC format compliant).
It uses a VTR to record and play back with a rotating head, and its specifications have been set with consideration to television standard formats.

The digital audio systems that use VTRs that are now available in the world were developed in countries that use the NTSC system, so these systems use NTSC VTRs, and at the same time, the digital audio system uses a different video recording system. When recording or playing back video on a VTR, the video must follow the television standard format of other regions.

In this case, in areas where the NTSC system is used, the digital audio system and the VTR used for video use the same system, so synchronized operation using time codes is easy.

However, in regions where the PAL system is used, the VTRs used to record and play back video are of course PAL systems, and are not used in digital audio systems.
NTSC VTRs and PAL VTRs have different time codes, making synchronized operation impossible.

(Problem to be solved by the invention) For example, if a musical is performed in a PAL region, the video will be a PAL VTR and the audio will be NTSC.
If the video was recorded on a NTSC VTR, the NTSC and PAL VTRs must be played back in synchronization. However, in the past, there was no device to synchronize VTRs of different systems, so synchronization was simply done by intuition, and there was no other reliable method. The only solution is to use a television standard conversion device to convert the VCR on the video side.
One possible method is to convert the PAL format to the NTSC format, make the formats the same, and synchronize, but in this case, the standard format conversion equipment would be very expensive, the image quality would deteriorate, and there would be further problems. However, there were problems such as the need for pre-processing before conversion, which took time.

(Means for Solving the Problems) In order to solve the above problems, the present invention reproduces recorded signals of the first television standard system and the second television standard system in which the number of frames is an integer ratio. A television signal synchronizing device for synchronizing reproduction signals of a first and second reproducing machine, the apparatus comprising: a synchronizing signal generating means serving as a reference for operating the first reproducing machine and the second reproducing machine in synchronization; A time code converter that converts the time code obtained from the playback signal from the first playback device to the time code of the second television standard system, and the converted time code obtained from this time code converter and reproduction from the second playback device. It is equipped with a time code comparator that compares the time code obtained from the signal, and a memory that sequentially stores the playback signal from the second playback device. To provide a television signal synchronization device characterized in that the time codes of a playback signal of a playback device and a readout signal of a memory are made to match.

(Embodiment) FIG. 1 is a block system diagram of an embodiment of the television signal synchronization device of the present invention.

In the figure, 1 is a PAL VTR, and 2 is a PAL VTR.
It is an NTSC system VTR, and each VTR has an address code used for tape editing, etc.
PAL format VTR1 uses EBU time code, NTSC
The VTR2 system is a model that can use SMPTE time code.

3 is a synchronization signal generator, 4 is a synchronizer, and includes a frequency converter 5, a time code converter 7, a time code comparator 8, and a memory (RAM) 11. 6 and 10 are VTRs
1 and 2 playback time code output terminal, 1
2 and 17 are video signal output terminals of VTRs 1 and 2. 9 is a digital audio processor that extracts a digital signal from the video signal output from the VTR 2, converts it into an analog audio signal, and demodulates it. 15 and 16 are output terminals for demodulated audio signals.

In the above configuration, VTR 1 plays back a magnetic tape on which video information signals are recorded in the PAL format, and VTR 2 plays back a magnetic tape on which digitally encoded audio information signals are recorded as pseudo video signals in the NTSC format. It is something.
A synchronizing device for synchronously operating the VTRs 1 and 2 of different systems will be described below.

EBU time code used for VTR1 (PAL system) and VTR2 (NTSC system)
The addresses for hours, minutes, and seconds are the same as SMPTE time code, but since the number of frames is 25 frames per second in the PAL system and 30 frames per second in the NTSC system, the frame address EBU time code (PAL
For SMPTE time code (NTSC system), it is numbered 0 to 24, and for SMPTE time code (NTSC system), it is numbered 0 to 29, which are different for both systems.

However, the EBU frame number 0 and
Frame number 0 of SMPTE matches, frame number 5 and number 6, number 10 and 12, number 15 and 18, and number 20 and 24 respectively, and both frames are in the ratio of 5:6. matches. The situation is shown in Figure 2.
It is shown as a chart of time code frame synchronization between SMPTE and EBU. The present invention has been made by focusing on the fact that both types of frames match.

The VTR 1 is synchronized with the PAL frame cycle by a 25 Hz synchronization signal output from a synchronization signal generator 3. In addition, the synchronization signal generator 3
The output signal is supplied to the frequency converter 5 in the synchronizer 4 and converted into a 30 Hz signal in order to synchronize the frame cycle of the NTSC system.
The 30 Hz signal output from the frequency converter 5 is synchronized with a digital audio processor 9, and via the processor 9 is synchronized with the frame signal of the VTR 2. Note that the frequency converter 5 outputs
The 30 Hz signal may synchronize the VTR 2 and synchronize the frame signal of the digital audio processor 9 via the VTR 2.

In the end, the signal output from the synchronization signal generator 3 becomes the reference, and the VTR 1, time code converter 7, and VTR
2 and the digital audio processor 9 can be synchronized.

Playback output from time code output terminal 6
The EBU timecode is supplied to a timecode converter 7. And in the time code converter 7
EBU time code frame number 0, 5, 10,
15 or 20 and the corresponding SMPTE timecode frame number 0, 6, 12, 18 or 24
The time code is converted into a synchronized SMPTE or equivalent time code at some point, and the converted time code is supplied to the time code comparator 8.

The time code comparator 8 uses the SMPTE time code output from the time code output terminal 10 of the VTR 2 and the output signal of the time code converter 7.
A comparison is made with the SMPTE or equivalent converted time code. As will be described later, this time code comparator 8 is based on the time code of the VTR 1,
VTR2 detects the difference with the time code of VTR2 and
and controls the memory 11 side, and adjusts the time code on the VTR 2 side.

When starting operation, first start VTR1, then
Start VTR2 (to use VTR1 as a reference,
(Start it first) From the opening staff, start with VTR1.
The time code with VTR2 does not match and the difference is often large.

Next, the time code comparator 8 compares the converted time code from the time code converter 7 with the time code of the VTR 2.

Now, if the result from time code comparator 8 is that the time code of VTR 2 is approximately +20 frames outside the converted time code (VTR 1), time code comparator 8 supplies a control pulse to VTR 2. Then, the tape running mode of VTR 2 is controlled to fast forward, rewind, or pause so that the time code of VTR 2 precedes the converted time code (VTR 1) by about +20 frames.

The reason why the preceding time code is set to approximately +20 frames is because the maximum capacity written to the memory 11 is 40 frames in this embodiment, as will be explained later.
The number of preceding frames is determined by the maximum capacity of the memory 11.

At this time, because I controlled the running mode of VTR2,
There may be cases where VTR1 and VTR2 are out of synchronization, but in that case, as described above, the synchronization signal output from synchronization signal generator 3 causes VTR1 and VTR2 to become out of synchronization.
As a result, the frame is synchronized with VTR2.

On the other hand, the pseudo video signal played by the VTR 2 is supplied to the digital audio processor 9 via the video signal output terminal 12, where the digital signal is taken out and transferred to the data write bus line 1.
A digital signal is written into the memory 11 via the digital signal 3. In this embodiment, the maximum capacity of the amount written to the memory 11 is 40 frames in video signal terms, so the time code of that frame is approximately 20 frames (more than the converted time code of the VTR 1) (memory 11
(approximately half of the maximum capacity of 40 frames) If it is written to memory 11 in advance, memory 1
1 stores only 40 frames of the playback signal of VTR 2 while being updated sequentially via the bus line 13. However, if the time code of the playback signal of VTR 1 is used as a reference, the memory 11 stores 20 frames each of the front and back. The range is memorized. in this state
The VTR1 and VTR2 operate synchronously using the output signal of the synchronization signal generator 3 as a reference.

Therefore, the time code comparator 8 compares the converted time code (the time code of the reproduced signal of the VTR 1 converted by the time code converter 7) and the time code of the reproduced signal of the VTR 2, and based on this result, the time code of the reproduced signal of the VTR 2 is stored in the memory 11. By changing the read address, it is made to match the time code of the reproduction signal of the VTR1.

Here, the memory 11 includes a memory element section and a control section that controls reading and writing of signals with respect to the memory element section.

The signal read out via the bus line 14 is then supplied to the digital audio processor 9, where it is converted into an analog audio signal by a D/A converter in the processor 9 and sent to output terminals 15, 16.
It is output from

Therefore, VTR1 output from output terminal 17
Video signals to be played (PAL format) and VTR2 (NTSC format) output from output terminals 15 and 16
This will allow synchronization with the audio signal being played.

In this embodiment, the read timing of the memory 11 can be adjusted manually from outside. In addition, if the magnetic tapes played back by VTR1 and VTR2 are magnetic tapes in which the start of the time code does not match and is recorded in a shifted state, the offset mechanism provided in the time code comparator 8 is used to adjust the start of the time code. .

Although this embodiment uses a VTR as a playback device, the present invention is also applicable to a playback device that uses a disk as a recording medium, for example.

(Effects of the Invention) According to the present invention, synchronized operation of VTRs of different television standard formats is reliably possible without relying on intuition, and compared to the case where one video signal is format converted, It has unique advantages such as no image quality deterioration due to conversion, no need for extremely expensive format conversion equipment, and synchronization can be achieved in a short time.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the television signal synchronization device of the present invention, and FIG. 2 shows a chart of frame synchronization of time codes between SMPTE and EBU. 1, 2... VTR, 3... Synchronization signal generator, 4... Synchronizer, 5... Frequency converter, 6, 10... Time code output terminal, 7... Time code converter,
8...Time code comparator, 9...Digital audio processor, 11...Memory, 12, 17...Video signal output terminal.

Claims (1)

[Scope of Claims] A system for synchronizing the reproduction signals of first and second reproduction machines that reproduce recorded signals of a first television standard system and a second television standard system in which the number of frames is in an integer ratio. A television signal synchronizer, comprising: a synchronization signal generating means serving as a reference for synchronizing operation of the first regenerator and the second regenerator; and a time code obtained from the reproduced signal from the first regenerator. a time code converter that converts the time code to the time code of the second television standard system; and a time code that compares the converted time code obtained from the time code converter with the time code obtained from the playback signal from the second playback device. It comprises a code comparator and a memory that sequentially stores the reproduced signal from the second reproducing device, and controls the reading position of the memory based on the result of the time code comparator to match the reproduced signal from the first reproducing device. A television signal synchronization device characterized by matching a time code with a memory readout signal.