JPH01233886A - Synchronizing device - Google Patents

Abstract

PURPOSE:To attain synchronizing running even to two sets of recording and reproducing devices having a difference in the number of revolutions for a rotary drum by applying the control of synchronizing running in a real time being the conversion of a time code. CONSTITUTION:A video signal and an audio signal are recorded and a time code is recorded, and a 3/4inch video tape is used as a master and the tape is reproduced by a 3/4inch video tape recorder(VTR) 12. The reproduced time code is converted in a real time by a real time converter 15 and when the sub code sending timing pulse from a DAT 13 is inputted to a real time converter 15, the value of a timer 14 is applied and fed to a control section 17. The control section 17 compares the data added with time offset in the real time supplied from the real time converter 15 with the real time data sent in the readout timing from the DAT 13, sends back a running control signal to the DAT 13 corresponding to the difference to control the tape running. Thus, the two sets of recording and reproducing devices with the different number of revolutions of the rotary drums are run synchronously.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a synchronizing device, and particularly to a video tape recorder (
Editing images (video signals) and sounds (audio signals) by synchronizing two recording/playback devices, such as a VTR (hereinafter referred to as VTR) and an audio tape recorder (hereinafter referred to as ATR), using time codes. The present invention relates to a synchronization device for performing synchronization.

(Conventional technology) Conventionally, concerts and natural I! Various subjects and sound sources such as Im are recorded (recorded) using VTRs, ATRs, etc., and further edited to produce so-called small video software such as video discs and recorded video tapes. Furthermore, as opposed to fixed head type ATRs, rotating head type ATRs (rotating head type digital audio tape recorders), which have higher sound quality, have been used. An example thereof will be explained below.

For example, consider making a live recording from a concert venue and producing video software.

In Figure 6, the video and audio signals recorded by a video camera and microphone at concert venue 1 are as follows:
Video recording is performed by a plurality of VTRs (A) 2 and VTR (B) 3, and audio recording is further performed by ATR (A). At that time, the time code output from the time code generator 5 is supplied to each device (2°3.4), and the same time code is recorded on each tape run by each of these devices.

Further, the video is edited based on the VTR (A) 2 and VTR (B) 3 (not shown), and the video tape is unified (that is, the video signal is edited into one tape). Do this. Then, continuous time codes are recorded again on this converted videotape (hereinafter referred to as the converted videotape).

Next, as shown in FIG. 7, the above-mentioned one-tree video tape is played back by the VTR (C) 6, and the time code recorded therein is supplied to the synchronizer/controller 8.

In addition, the same time code as the time code recorded on the unified video tape run by the VTR (C) 6 mentioned above is continuously recorded in advance on the tape run by the ATR (B) 7. put.

The synchronizer/controller 8 is the VTR
(C) 6 is used as the master and its time code is read, and ATR (A) 4 and ATR (B) 7 are respectively slaves and their time codes are also read. Compare the time codes, control the running of ATR (A) 4 and ATR (B) 7 according to the comparison result, and control the running of VTR (C) 6, ATR (A) 4 and A
4, which runs in synchronization with TR(B) (ATR<A), does not run continuously, so an offset is applied as a time code. ) During this synchronized running, by recording the audio signal played back at ATR (A > 4) at ATR (B) 7, the same time code as that recorded on the above-mentioned unified video tape is obtained. Recorded audio tape (
Hereinafter, an audio tape (hereinafter referred to as a "realized audio tape") is obtained.

Next, as shown in FIG. 8, the VTR (C) 6 reproduces the unified videotape and supplies its time code to the synchronizer/controller 8. Also, ATR
(B) At step 7, the above-mentioned unified audio tape is played back and its time code is supplied to the synchronizer/controller 8.

The synchronizer/controller 8 compares the time codes supplied from the VTR (C) 6 and the ATR (B) 7, and depending on the comparison result, the synchronizer/controller 8 outputs the rATR (B) 7 (7).
Control driving tl] L,, VTR (C) 6 and ATR (B) 7
VTR (C) 6 and ATR (B) 7
Line input the video signal and audio signal from each to the audio/video cutting machine 9,
Create a cutting mask.

(Problem to be Solved by the Invention) As mentioned above, as a means of synchronizing two types of recording and reproducing devices (for example, VTR and ATR, VTR and VTR), the unified standard called SMPTE time code is used. A method is used in which the time code is recorded as tape position information.

However, this is a device like a VTR in which the rotation speed of the rotating drum is the same or very close (black and white synchronization is 30 rotations/s, N
TSC color synchronization is effective for 29.97 revolutions/s, for example, rotating head type digital audio
This method cannot be applied to a recording/reproducing device such as a tape recorder (33 rpm) in which there is a difference in the rotational speed of the VTR and the rotating drum because the same fill h (h) of the rotating drum cannot be obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology and provide a synchronizing device that enables synchronized running even for two recording/reproducing devices whose rotating drums have different rotational speeds. purpose.

(Means for Solving the Problem) In order to achieve the above object, the present invention records a frame-by-frame time code on a first recording medium run by a first recording/reproducing device, and means for converting the code into real time and recording the real time on a second recording medium running at a second recording/reproducing station; reproducing the time code recorded on the first recording medium; This is converted into real time, this real time is compared with the real time recorded on the second recording medium, and the second recording/reproducing device is controlled according to the comparison result. The present invention provides a synchronization device including means for causing a recording medium to run in synchronization with the first recording medium.

(Function) The synchronizer with the above configuration converts the time code into real time, and uses this real time to determine the speed of synchronized running.
Do m.

(Example) As an example of the synchronization device according to the present invention, a system for synchronizing a VTR and a rotary head type digital audio tape recorder (hereinafter referred to as DAT) will be explained. The algorithm for time) conversion and its recording will be explained.

FIG. 1 is a diagram showing the configuration, and FIG. 2 is a diagram showing a timing chart.

In Fig. 1, 11 is a mask 1 for playing back a video tape (1-inch master tape) on which source images (video signals) and sounds (audio signals) are recorded.
It is an inch VTR.

12 is a 3/4 inch VTR that runs a 374 inch video tape for recording/playback, and 13 is a DAT that runs a digital audio tape for recording/playback.

14 is a real time converter 15 whose time code data will be described later.
This is a timer that starts counting operation from the time of input of the reset pulse outputted from the real-time converter 15 for each frame.

Reference numeral 15 denotes a real-time converter that converts the input time code into real-time J based on a conversion formula described later and outputs the converted time code.

Reference numeral 16 denotes a time code generator that generates a time code that is standardized such as SMPTE time code.

As shown in Figure 9, the SMPTE time code contains information such as hour 1 minute 0 second, frame, synchronization pit, etc.
It consists of bits (one frame) and is basically sent continuously at a rate of 30 frames/s. In addition, SMPTE time code uses a means called drop frame (drop frame mode) to correct the frame error between real time (30 frames/s) and VTR (29,97 frames/s). The time corresponding to the number of frames when considered as frames/S'' plus the ``time equivalent to the number of dropped frames'' is defined as ``real time 1.'' In other words, r real time J means that the time code is This is the physical time based on the "0" frame of "0°" hour "0" minute 11091 seconds when there is no drop frame or frame (in non-drop frame mode).

With the above configuration, the video signal obtained by playing back the 1-inch master tape with the master 1-inch V T Rit is 37
The audio signal is supplied to the 4-inch VTR12, and the audio signal is also supplied to the 374-inch VTR12 and DAT13.
t3/4
A video signal and an audio signal are recorded on a video tape, and an audio signal (digital signal) is recorded on a digital audio tape in the DAT 13.

At the same time, the time code output from the time code generator 16 is supplied as is to the 374-inch VTR 12 and recorded on a 3/4-inch videotape.

On the other hand, the above time code is supplied to the real time converter 15, where it is converted into real time, and D A
The recording timing pulse from T13 is transmitted to real time converter 1.
5, the value of timer 14 (offset: d
t, , dt2,...) are added and DAT13
and recorded in the subcode area of the digital audio tape (the timer 14 is supplied to the real-time converter 1
(Reset is done by a pulse (reset pulse) synchronized with each time code input timing sent from 5)
.

Note that this recorded real time is RT. , ni=o.

1, 2. ). Also, real-time RT, H(i-
0, 1, 2,...) Timing chart for finding
This is shown in Figure 2.

Next, the algorithm for synchronous travel control will be explained.

FIG. 3 is a diagram showing the configuration, and FIG. 4 is a diagram showing a timing chart.

In Figure 3, a video signal and an audio signal are recorded using the procedure described above, and a time code is also recorded.
Using a 74-inch videotape as the master, convert this to 374
Playback on inch VTR12. The reproduced time code is supplied to the real time converter 15, where it is converted into real time in the same manner as described above, and the subcode sending (reading) timing pulse is input from the DAT 13 to the real time converter 15. At the point in time, the value of timer 14 (time offset: dt,

dt2. ) is added to the control unit 17 (the timer 14 receives a pulse (reset 1 -
pulse).

Note that the converted real time is RTvi (i=o, 1°2,
).

The control unit 17 converts the real-time data (RT' = 0.1, 2...: sub-Dk'' code) sent from the DAT 13 at the read timing (every rotation of the rotating drum) to the real-time data. The real time (R
Tvi: i =0.1, 2. -) with a time offset (dtA l = 0.1.2...) added to the data, and output the travel control signal (fast forward, 1 rewind, 3x speed, etc.) corresponding to the difference to the DAT13. send it back to
Controls the tape running. Then, repeat this operation to reduce the time difference between the two.

Further, when the time difference between the two tapes disappears, it is assumed that the tape positions of both tapes match in time, and from then on, servo is applied to the D A T 13 so that the times do not deviate.

Here, a dedicated method for converting time code into real time will be described below.

First, set the time code (Ti> to f"T11i".

“TH minutes, TSi seconds, TFi frames”
shall be. In addition, the real time shall be converted to units of seconds.

■X7L/-mu/S (X=30.24.25) When converting the tuterm code to real time, use the real time R
Ti [seconds] is calculated using the following conversion formula (1).

RTi [seconds] = 3600x T lli+ 6
0x T Hi+ T Si+ (1/X) XT
Fi-11) ■Drop frame mode (2
9.97 frames/S) time code to real time, 3 of the drop frame time code.
The deviation from the time code (error from real time) of 0 frame/S is as shown in FIG.

In the same figure, the frame ratio of NTSC color synchronization is 29.
．． If it is 77 frames/S, the error do=0, but
In reality, it is 29.97002616 frames/S, so d≠O, and the value of error do accumulates every 10 minutes.

Therefore, the real time RTi [seconds] is calculated using the following conversion formula. However, the last term (error) of this equation (■) DTi
The real time is calculated using as a correction term.

RTi [seconds] = 3600x T IIi + G
Ox T Hi + T Si + (1/30) x TFi + DTi ...Q) DTi [seconds] = ((6X
T IIi+ INT(T Hi/ 10))xd
O+dk) x103 + (30xl'-3i+TFi) xdT...
(3) However, k = T Hi -10x INT(T
Hi/10).

dT [seconds] = (1/29.97002616-1
/30>Here, INT(A) is the integer part of A, dk(
dk<0:=0.1. ..., 9) represents the error [m seconds] with respect to the real time at each correction point.

To convert the time code as described above into real time, one calculation is performed in the real time converter 15 of FIGS. 1 and 3.

In addition, in the above embodiment, a VTR and a rotary head type DAT are used.
Although the synchronized running has been described, it goes without saying that the present invention can also be applied as a synchronizing device when two recording and reproducing devices, such as tape devices, whose rotating drums have different rotational speeds perform the same iJ running. It is.

(Effects of the Invention) As described above, according to the 1#J device of the present invention, it is possible to synchronize two recording and reproducing devices such as a VTR and a rotary head type DAT whose rotating drums have different rotational speeds. This simplifies the configuration, and also enables accurate synchronized travel (driving) even when the time code that is the standard for synchronized travel has a drop frame, allowing for higher-density recording compared to fixed head ATRs. By using the rotary head type ΔTR, that is, the rotary head type DAT, which can perform synchronized running, it has the advantage of being able to perform mastering (editing work) with a compact, lightweight, and high-quality 11.

[Brief explanation of the drawing]

1 and 3 are diagrams showing the configuration of an embodiment of the synchronizer according to the present invention, FIGS. 2 and 4 are diagrams showing timing charts of an embodiment of the synchronizer according to the present invention, and FIG. The figure shows how to change time code to real time! ! ! 6 to 8 are diagrams showing an example of a conventional video editing device, and FIG. 9 is a diagram showing the structure of an SMPTE time code. 11...7 Meta 1 inch VTR1 12-374-1' inch VTR113-D A T,
14.9 I? , 15... Real time converter, 1G...
Time code generator, 17...control unit. Fig. 1 Fig. 2 Fig. 3 (ffi=o, 1....) Fig. 7 (Special 0.40HO,, to 051.% to 052F--
9th): /'I(lyt): S (kl: r(71-
k) OuO4's''/p 01tOJ50t --
−Note

Claims (2)

[Claims] (1) Record a frame-by-frame time code on a first recording medium run by a first recording/playback device, convert the time code to real time, and convert this real time to a second record/playback device. means for recording on a second recording medium that is being run; reproducing the time code recorded on the first recording medium, converting this into real time, and recording this real time and the second recording medium; a synchronizing device, comprising: a means for comparing the real time of the recorded data and controlling the second recording/reproducing device according to the comparison result to cause the second recording medium to run in synchronization with the first recording medium; . (2) If the timecode has a drop frame,
2. The synchronization device according to claim 1, further comprising means for converting the real time by using as a correction term an error from the real time converted using a time code having no drop frame as a reference for each frame.