JPH034991B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronization device used, for example, in videotape editing.

In editing a videotape, for example, when inserting a desired video from an original tape into a predetermined part of the master tape, the beginning of the desired video on the original tape (editing point on the original tape side) and The absolute address of the start end of a predetermined portion of the master tape (editing point on the master tape side) is converted into a time code and set in each editing device. Next, the playback side VTR and recording side are loaded with the original tape and master tape, respectively.
The VTR rewinds the original tape and the master tape by a predetermined amount from the editing point located at the address obtained by converting the set time code, waits for it, and then directs the original tape and master tape from that position (standby position) to the editing point. Transfer the original tape and master tape. At this time, the time codes recorded on the original tape and master tape are played back, and the difference between the address obtained by converting these time codes and the preset absolute address of the edit point of the original tape and master tape is calculated. Then, the transport of the original tape is controlled (phased) so that these difference values match each other. Then, when the difference between the address obtained by converting the time code played from the original tape and master tape and the preset absolute address of the editing point of the original tape and master tape becomes 0, playback is performed from the original tape. recorded video signals on a master tape.

Incidentally, since the minimum unit of an absolute address is one frame, while the original tape and master tape are being transferred from the standby position to the editing point, these tapes are synchronized down to the unit of one frame.

Therefore, on the master tape, synchronization signals and the like are continuous between the previously recorded video and the newly recorded video from the original tape, making it possible to perform editing without disturbance.

Next, when using the video reproduced from the original tape for broadcasting, a reference time generator is provided that generates a reference time in which the hours, minutes, and seconds digits advance at the same rate as real time. By setting a desired value of the reference time and the absolute address of the starting edge of the desired video on the original tape, the original tape is rewound by a predetermined amount, and then the original tape is transported toward the starting edge of the desired video. When the reference time generated by the reference time generator reaches the set value, broadcasting of the reproduced video signal starts from the beginning of the desired video on the original tape.

By the way, in a VTR, it is possible to transport the tape at a speed different from that during recording, and perform slow retransmission, double speed playback, still playback, etc. Particularly in such a case, the reproducing head should be provided with a position changing means such as an electro-mechanical conversion element so that tracking is always performed correctly and a normal video signal can be obtained even during the above-mentioned special reproduction. Can be done.

Therefore, it was proposed to attach the original tape to a VTR capable of special playback and use the special playback footage for editing and broadcasting.

However, in conventional devices, when the master tape reaches the edit point or when the reference time value generated by the reference time generator reaches the desired value, the original tape speed changes to either the master tape speed or the reference time value. Since the original tape's transport speed is equal to that at the time of recording, it was not possible to edit or broadcast using the special playback VTR described above.

In view of these points, the present invention is designed to enable phase adjustment even when special reproduction as described above is being performed. Referring to the drawings below,
An embodiment of the present invention will be described.

In FIG. 1, 1 is the original tape. The distance from the reference point on the original tape 1 is converted into a time code as an absolute address of a diagonal track, that is, converted into a time code indicating the time it takes to transport the original tape 1 from the reference point at a reference speed, Recorded on original tape 1. This tape 1 is wound around a rotating head drum 2 and is transported by a capstan motor 3. Further, 4 is a master tape. The distance from the reference point on the master tape 4 is converted into a time code as an absolute address of a diagonal track, that is, converted into a time code indicating the time it takes to transport the master tape 4 from the reference point at a reference speed, It is recorded on master tape 4. This tape 4 is wound around a rotating head drum 5 and is transported by a capstan motor 6.

Further, a magnetic head 7 is placed in contact with a predetermined portion of the original tape 1, and a signal from this head 7 is supplied to a time code reading circuit 8, whereby the time code of the original tape 1 is read out. This read time code is supplied to the processing circuit 9. Further, a magnetic head 10 is placed in contact with a predetermined portion of the master tape 4, and a signal from this head 10 is supplied to a time code reading circuit 11 to read out the time code of the master tape 4. This read time code is supplied to the processing circuit 9.

Furthermore, a reference time code is supplied to the processing circuit 9 from a reference time generator 12 which generates a reference time in which the hour, minute, and second digits are stepped at the same step rate as real time. Further, the contents (initial value) of the reference time generator 12 are preset to a predetermined value by a signal from the processing circuit 9.

The motors 3 and 6 are controlled by signals from the processing circuit 9.

Further, signals from the rotary head drum 2 are supplied to the rotary head drum 5 through a video processing circuit 13 such as a time base collector. Further, a control signal from the processing circuit 9 is supplied to the video processing circuit 13.

Also, the speed ratio x of the original tape 1 (the ratio of the tape speed during playback to the tape speed during recording),
Setting signals such as Tcx, which is the absolute address of the start of the desired video on original tape 1, and Tcr, the desired playback time or the time indicated by the time code recorded at the start of a predetermined portion of master tape 4, are sent to terminal 1.
4 to the processing circuit 9.

Furthermore, a memory 15 in which operating programs and the like of the processing circuit 9 are written is provided, and signals from the memory 15 cause the processing circuit 9 to perform processing operations, and data etc. from the processing circuit 9 are transferred to the memory 1.
Recorded at 5.

In this memory 15, a processing program as shown in the flowchart of FIG. 2, for example, is written. This program uses the reference time from the reference time generator 12, and when the reference time reaches a predetermined value, the original tape 1 is
A case is shown in which a video signal is reproduced from the starting end of a desired video.

Next, with reference to FIG. 2, when the reference time generated by the reference time generator 12 reaches a predetermined value, the video signal starts from the beginning of the desired video of the video signal recorded on the original tape 1. The transfer control of the original tape 1 will be explained using the case where the original tape 1 is played back as an example.

The absolute address of the start of the desired video on original tape 1, that is, the time Tcx required to transport original tape 1 from the reference point to the start of the desired video at the standard speed (tape speed at the time of recording), the tape at the time of recording Speed The time required for phase adjustment when playing back from the start of the desired video at the same speed, α, the ratio of the tape speed during playback to the tape speed during recording x
Then, in step, the original tape 1 is transferred to the absolute address position indicated by Tcx-α·x . . .1. This operation is called pre-roll, and the position after transfer is called a standby position in this specification.

Next, in step, an initial value of the reference time indicated by Tcr-α-n . Note that Tcr indicates the desired value of the reference time generated by the reference time generator 12, and n indicates the desired value of the reference time generated by the reference time generator 1.
The time corresponding to the time required for the operation of No. 2 to stabilize is shown.

In a further step, the reference time generated by the reference time generator 12 is read by the processing circuit 9 and set in the register in the memory 15 as the time Tr.

Next, in the step, it is determined that Tr≧Tcr−αm . Note that m indicates the time required for the capstan motor 3 to start up, and n≧m≧0...4.

If the third equation holds true in step, the capstan motor 3 is driven at a speed x times the tape speed during recording.

In step, the time code read from the original tape 1 by the time code reading circuit 8 is read by the processing circuit 9 and set in a register in the memory 15 as a time code.

In step, the reference time generated by the reference time generator 12 is read by the processing circuit 9, converted into a time code, and stored in the memory 15.
is set as the updated timecode in the register within.

In the step, the time code set in the register in the memory 15 in the step is converted into time Tx. Also, in the step, the time code set in the register in the memory 15 is converted into a time Tr. Then, it is determined that (Tcr-Tr)≧<Tcx-Tx/X...5. When the left side is large, the process proceeds to step, and when the right side is large, the process proceeds to step.

In the step, Y=(Tcr-Tr)-Tcx-Tx/x...6 is calculated, and in the step, based on the value of Y, the capstan motor 3 adjusts the tape speed during recording to (x〓f(Y )) times (here, the symbol "-" is selected when the tape is transported in the forward direction and played back, and the symbol "+" is selected when the tape is transported in the reverse direction and played back. ).

In the step, T=Tcx-Tx/x-(Tcr-Tr) is calculated, and in the step, based on this Y value, the capstan motor 3 adjusts the tape speed (x±f(Y)) during recording. times (here, the symbol "+" is selected when the tape is transported in the forward direction and played back, and the symbol "-" is selected when the tape is transported in the reverse direction and played back. ) is driven at a speed of

In step, when the magnitudes of the right and left sides of the fifth equation are equal, the process advances to step and the capstan motor 3 is driven at a speed x times the recording speed.

In the step, it is determined that Tr≧Tcr...8, and if the 8th equation does not hold, the process returns to the step. Also, when the 8th formula holds,
In step, the capstan motor 3 is driven at a speed x times the recording speed, and the series of programs ends.

As described above, in the apparatus of the present invention, when the reference time generated by the reference time generator 12 reaches a desired value, the video signal is started from the beginning of the desired video of the video signal recorded on the original tape 1. When playing, first start from the beginning of the desired video.
Original tape 1 is transferred to the absolute address position indicated by Tcx - αx, and that position (standby position)
will be waited for. When the reference time generated by the reference time generator 12 reaches (Tcr-α-m), tape transport is started so that the tape speed of the original tape 1 becomes x times the tape speed at the time of recording. Furthermore, after the transfer of original tape 1 is started, the difference between the time Tx obtained by converting the time code played from original tape 1 and the time Tcx indicating the position (address) where the start of the desired video is recorded (this The difference indicates the time it takes to transport the original tape at the standard speed (recording speed) from the position on the original tape where the time code is currently being played to the position where the start of the desired video is recorded. ) original tape 1,
The time and speed ratio that should be spent when transporting the recording medium from the position where the current time code is being played to the position where the start end of the desired video is recorded at a speed different from the traveling speed of the recording medium at the time of recording. Based on x, the speed of the original tape is controlled and phasing is performed. Then, when the reference time generated by the reference time generator 12 reaches the desired value by transporting the original tape 1 at a speed of x〓f(Y) during recording or x times the speed during recording. The address obtained by converting the time code reproduced from the original tape 1 becomes the absolute address Tcx on the tape of the starting end of the desired video, and the video signal is reproduced from this point on.

In this way, the pre-roll of the original tape 1, the phase adjustment, and the reproduction of the video signal recorded on the original tape 1 are performed.

In the example explained with reference to FIG. 2, the value of the reference time generated by the reference time generator 12 that generates the reference time that advances at the same step speed as real time reaches the desired value. This is a case where playback is started from the beginning of the desired video on the original tape 1, but when the video signal recorded on the original tape 1 is played back and recorded on the master tape 4, as shown in FIG. In the explanation of the flowchart shown in , instead of the reference time Tr generated by the reference time generator 12, a time code obtained by converting the time code reproduced from the master tape 4 by the time code reading circuit 11 is used. Time can be used as Tr. Also, instead of the desired value Tcr of the reference time generated by the reference time generator 12, a time code indicating the absolute address of the desired recording start point of the master tape 4 recorded on the master tape 4 is used. The time obtained by conversion may be used as Tcr. In addition, in the step, the master tape 4 is read so that the address of the point where the time code is read from the master tape 4 by the time code reading circuit 11 is the address indicated by (Tcr-α-n). All you have to do is transfer it. At this time, n corresponds to the start-up time of the capstan motor that drives the master tape 4. After the step, the master tape 4 may be transported in the forward direction at 1x speed, and the time obtained by converting the time code read from the master tape 4 at that time may be used as Tr.

According to the present invention, the original tape 1 at the time of recording
The standby position of the original tape 1 is determined according to the ratio x of the running speed during playback to the running speed of Start transferring the original tape 1, and calculate the difference ( This difference indicates the time it takes to transport the recording medium from the position on the original tape where the time code is currently being played to the position where the start of the desired video is recorded at the traveling speed of the recording medium at the time of recording. ), the speed of the original tape 1 is determined based on the time and speed ratio Since it controls and performs phase adjustment,
When the reference time generated by the reference time generator 12 reaches the desired value Tcr, the original tape 1 accurately reaches the start of the desired video, and the running speed of the original tape 1 at that time is determined. It is possible to accurately increase the traveling speed by x times the traveling speed at the time of recording. Therefore, even during special playback (variable speed playback), there is an effect that playback can be started from the starting end of a desired video signal at a desired time and at a desired playback speed.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an example of the present invention, and FIG. 2 is a flowchart for explaining the same. 1 is an original tape, 3 is a capstan motor, 7 is a magnetic head for time code detection, 9 is a processing circuit, and 12 is a reference time generator.

Claims (1)

[Claims] 1. After a recording medium on which an information signal is recorded is kept at a standby position, the recording medium is transported at a speed different from the traveling speed of the recording medium at the time of recording, and moved to a desired playback start position. In a synchronizing device that controls the transport of the recording medium so as to start playback from A predetermined phasing time required to transport the recording medium at the recording speed and start reproduction from the reproduction start position, and start the desired reproduction from the reference point at the traveling speed of the recording medium at the time of recording. a first calculating means for calculating the standby position based on the time taken to transport the recording medium to the position, and moving the recording medium from the current position of the recording medium to the playback start position at the speed of the recording medium at the time of recording. Based on the time required to transport the recording medium from the current position to the playback start position at a speed different from the traveling speed of the recording medium at the time of recording, and the ratio. A second device that calculates the running speed of the recording medium.
and a transporting means for transporting the recording medium, the transporting means transporting the recording medium to the standby position calculated by the first calculation means, and then transporting the recording medium to the standby position calculated by the first calculation means. A synchronizing device characterized in that the synchronizing device is configured to transport toward the regeneration start position at the traveling speed calculated by the second calculation means.