JPH0126232B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a variable speed playback system for video signals suitable for use, for example, in editing video tapes. When 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 master tape The time code of each starting end (editing point on the master tape side) of a predetermined portion is specified to the editing device. Then, each VTR moves the tape back a predetermined amount from the specified time code and starts playback from that position. It also detects the timecode from each tape, calculates the difference between these timecodes and the timecode of each specified edit point, and transports the original tape so that these difference values match each other. Control (phase adjustment). Then, when both of the differences become 0, the VTR of the master tape is put into the recording state and the desired video from the original tape is recorded. In other words, while the rewind portion is being transferred, control is performed so that the number of time codes up to each specified editing point is equal, and a time code is attached to each frame of the video. Therefore, the time it takes for each tape to reach the editing point is made equal, and frame synchronization is applied between the two tapes. 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. Similarly, when using video from the original tape for broadcasting, a standard time code generator is provided, and the desired playback time in this standard time code and the time code at the start of the desired video on the original tape are generated. By specifying , the original tape is rewound by a predetermined amount, playback of the original tape is started from a predetermined time before the playback time, phase adjustment is performed, and playback without disturbance is started at the playback time. By the way, in a VTR, the tape can be transported at a speed different from that at which it was recorded, allowing slow playback, double speed playback, still playback, etc. Particularly in such a case, the reproducing head should be provided with 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 load the original tape into a VTR capable of special playback and use the special playback footage for editing and broadcasting. At this time, when playing back the original tape, if special playback is performed with the playback speed fixed, such as 2x speed playback or 1/3x slow playback, and then edited and recorded on the master tape, the video will be relatively monotonous. You can only get the effect. Therefore, it is desirable to have a scanning system in which the playback speed can be arbitrarily changed according to the editor's intention, for example, slow playback is performed for a certain scene, and from there the playback speed is gradually increased to normal speed, and then returns to slow playback again. Ta. However, the signal from the VTR being played back at a playback speed that can be changed arbitrarily by the editor's manual operation,
Since the data was recorded on the master tape in real time, the following inconvenience occurs. That is, if the playback settings for the variable speed playback that have been once performed do not match the editor's intention, the above-mentioned editing and recording must be performed again from the beginning. You can also use the lever to set the speed as you intended.
Manual operations such as adjusting dials require considerable skill. Therefore, the present invention provides a video signal reproducing means having a variable speed reproduction function, a first specifying means for specifying the playback speed, a second specifying means for specifying the playback start point, and a reproduced video signal. a means for storing speed information corresponding to a designated playback speed; and a playback speed control means for controlling the playback speed of the video signal playback means based on the stored content of the speed information storage means. To provide a variable speed playback system for a video signal, which has a variable speed playback system and can automatically perform the same variable speed playback as rehearsal by sequentially reading out playback speed information arbitrarily specified by an operator from a storage means while observing a monitor means. It is. An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 5. In FIG. 1, reference numerals 1a to 1n indicate a plurality of playback machines loaded with original tapes, and any number of playback machines may be provided as required and operate in series. Reference numerals 2a to 2n are time code readout circuits provided corresponding to each of the playback machines 1a to 1n, and these time code readout circuits 2a to 2n read the time code of the original tape of each of the playback machines 1a to 1n. are read respectively. The read time code is then supplied to a central processing unit (hereinafter referred to as CPU) 3. Reference numeral 4 denotes a recording machine loaded with a master tape, and although any number of recording machines 4 may be provided as required, a case in which one recording machine 4 is typically provided is shown here. Reference numeral 5 denotes a time code reading circuit, which reads out the time code of the master tape of the recorder 4. This read time code is
Supplied to CPU3. The video monitor output from each of these playback machines 1a to 1n and the recorder 4 is supplied to the monitor controller 11, and the time code reproduced from each playback machine and recorder is sent from the CPU 3 to the monitor controller 1.
1 and an appropriately selected video signal is displayed on the monitor 12. At this time, if necessary,
A time code corresponding to the displayed video is superimposed on the monitor screen. Furthermore, a reference time code is supplied to the CPU 3 from the reference time code generator 6 . Also CPU
A signal from time code generator 3 presets the contents of time code generator 6 to a predetermined value. Control signals are then supplied from the CPU 3 to the tape running control circuit 7, and the signals from the tape running control circuit 7 drive the respective capstan motors of the playback machines 1a to 1n and the recording machine 4, which transport the tape (not shown). is controlled. Also, the speed ratio x of the original tape, the time code Tcx at the beginning of the desired video of the original tape,
Setting signals such as the desired playback time or the time code Tcr of the start of a predetermined portion of the master tape are sent from the keyboard 8 via the interface circuit 9.
Supplied to CPU3. Furthermore, a memory 10 in which operating programs and the like for the CPU 3 are written is provided, and processing operations of the CPU 3 are performed by signals from the memory 10, and data and the like from the CPU 3 are stored in the memory 10. A processing program as shown in the flowchart of FIG. 2, for example, is written in this memory 10. Note that this program shows the case where the reference time code from the time code generator 6 is used to reproduce the video from the original tape at a desired reproduction time. In the figure, when the program corresponding to the playback device 1a is started, the original tape of the playback device 1a is transferred to the time code position of Tcx±αx in step [1]. Note that α indicates a normal phase adjustment time. Next, in step [2], the time code Tcr-α-n is preset in the time code generator 6, and time codes are sequentially generated from this point. Note that n indicates the time required for the operation of the time code generator 6 and the like to stabilize. In addition, if you want to record the video on the master tape of the recorder 4 and edit it, use this step 2 to record the video on the master tape of the recorder 4.
The phase of the master tape is shifted to the time code position of (Tcr-α-n). Furthermore, in step [3], the time code generator 6
The time code is read and set in the register in the memory 10 as the reference time code Tr. Then, in step [4], it is determined whether Tr≧Tcr−α−m, and if this formula does not hold, the process returns to step [3]. Note that m indicates the time required for starting up the capstan motor of the regenerator 1a, etc., and n≧m≧0. If the equation holds true in step [4], then in step [5] the capstan motor of the reproducing device 1a is driven at a speed ±x times that of recording. Further, in step [6], the time code from the time code reading circuit 2a is read and set in the register in the memory 10 as the read time code Tx from the playback device 1a. Further, in step [7], the time code of the time code generator 6 is read and set in the register in the memory 10 as the reference time code Tr. Then, in step [8], it is determined that (Tcr-Tr)> = <(Tcx-Tx/+x), and if the left side is large, step

In step [9], Y=(Tcr-Tr)-(Tcx-Tx/±x) is calculated, and in step [10], based on this Y value, the capstan motor of the player 1a is adjusted to the ±during recording time. It is driven at a speed x±Δ(Y) times. If the right side is large in step [8], Y = (Tcx - Tx / ±x) - (Tcr - Tr) is calculated in step [11], and the capstan motor of the regenerator 1a is calculated in step [12]. is driven at a speed that is ±x〓Δ(Y) times that of recording. Furthermore, if both sides are equal in step [8],
At step [13], the capstan motor of the reproducing device 1a is driven at a speed ±x times that of recording. Then, in step [14], it is determined whether Tr≧Tcr, and if this formula does not hold, the process returns to step [6]. If the equation holds true in step [14], then in step [15] the capstan motor of the reproducing device 1a is driven at a speed ±x times that of recording, and the program is ended. The operation of such a program is performed in the same manner for the other playback devices 1b to 1n. Therefore, in this apparatus, the original tape of each playback machine is transferred to a position 〓xα from the starting edge of a desired video image, and is held at that position. When the time code of the reference time code generator 6 becomes (Tcr-α-m), reproduction of the original tape is started. Furthermore, during this playback period, the time until the original tape reaches the start of the desired video is calculated from the time code of the original tape, and the original tape is adjusted so that this time is x times the time up to the playback time. A phase is performed. Then, by transporting the original tape at a speed that is ±x times faster than when it was recorded, the time code of the original tape becomes Tcx at the playback time Tcr.
Playback starts from this point. In this way, the phase adjustment during variable speed playback, that is, the relative timing of the desired playback time or the time code of the start end of a predetermined portion of the master tape of the recorder 4 and the time code of the start end of a predetermined portion of the master tape of the specified player, is performed. The positional relationship is specified. The original tape images of each of the playback devices 1a to 1n are then played back and used for broadcasting, or recorded on the master tape of the recorder 4 and used for editing. Rehearsals are conducted and the most favorable one is selected. Therefore, in the present invention, when rehearsing for broadcasting or editing, the interface circuit 9,
Through the CPU 3 and the tape running control circuit 7, the designated playback device is sequentially put into a variable speed mode and its playback speed is controlled in relation to the time code. That is, the operator observes the playback video output from the playback device displayed on the monitor 12, and uses the keyboard 8 to determine the time code and playback speed.
and stores information on the locus of changes in playback speed from the start to the end of the desired playback time or edit point in the memory 10. If the time code (absolute address) reproduced by the playback device is used as the above-mentioned time code, the playback speed of the playback device will change in relation to the tape position of the playback tape, as shown in Figure 3. If the time code preset from the standard time code generator 6 to the CPU 3 is used as the above-mentioned time code, the playback speed of the playback device will change in relation to the real time as shown in Figure 4. I will do it. When using the former, the video content of each frame of the playback video signal and the playback speed at that point are programmed, so if the scene and playback speed are out of sync, this will not happen. After performing still playback for 10 seconds, the tape cannot be run again at the predetermined playback speed. On the other hand, when the latter method is used, the tape running speed is determined in accordance with real time, so it is possible to play stills for 10 seconds in a specific scene as described above, but due to errors in tape running, etc. The tape position, ie, each scene of the video, and the playback speed may not always match what was programmed during rehearsal. Therefore, in reality, a program operation is performed by selecting both or using both as necessary. Next, a method for effectively using the memory 10 when storing the playback speed in association with this time code will be described below. If time codes and playback speeds are made to correspond according to the curve shown in Figure 5, the capacity of the memory 10 would be extremely large if the playback speeds corresponding to all the timecodes were stored one by one. It becomes something big. Therefore, if the playback speed changes rapidly in response to a change in time code, such as between A and B in Figure 5, the playback speed should be adjusted per unit of time code, specifically per unit time or per unit tape length. The system memorizes how much the playback speed has changed, and in places where the change in playback speed is not very large in response to a change in time code, such as between CDs, it takes real time or To remember how much the tape position has changed. In this way, the memory capacity can be reduced by efficiently storing the relationship between playback speed and time code. Also memory 10
The information on the locus of speed change stored in can be modified by operating the dial knob of the keyboard 8 or the lever 8a. In the embodiment described above, the relationship between the time code data representing the tape position or real time and the playback speed is programmed, but considering the general relationship between speed, time, and position, for example, the relationship between real time and tape position can be programmed. It goes without saying that you can program the relationship with. In this way, the information on the best speed change locus corresponding to each playback device, which is stored in the memory 10 during broadcast or editing rehearsal, is reproduced at any time during broadcast or editing rehearsal or execution. For example, when editing, a program corresponding to each reproducing machine is used to store information about the trajectory of speed changes following the phase adjustment made as described above in relation to the time code.
When the video is taken out from the memory 10 by a command signal from the CPU 3, the first playback device 1a is first controlled according to the corresponding program, and the played video is transferred to a recorder that operates continuously while each playback device is in operation. recorded on 4 master tapes. Then the second player 2 according to the next corresponding program.
a is controlled, the reproduced video is recorded on the master tape, and this operation is repeated in the same manner up to the last reproducing device 1n, and the editing is completed. Furthermore, when broadcasting is performed, images reproduced by the reproduction machines 1a to 1n, which are sequentially controlled according to each program as described above, are used. As described above, according to the present invention, it is possible to adjust the phase during special playback, and also to control the playback speed of the playback device specified during rehearsal for broadcasting or editing in the special playback mode, and to store the trajectory of the speed change. However, since it can be reproduced at any time, it is possible to achieve labor saving and to obtain a versatile variable speed reproduction system for video signals.
Furthermore, since the memory being used can be made effective, various functions during editing etc. can be expanded, and the position of the reproduced signal can be associated with the position on the storage medium based on a predetermined designation.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
This figure is a flowchart for explaining the operation of FIG. 1, and FIGS. 3 to 5 are characteristic diagrams for explaining the operation of FIG. 1. 1a to 1n are playback devices, 2a to 2n are time code reading circuits, 3 is a central processing unit (CPU), 4 is a recording device, 5 is a time code reading circuit, 6 is a time code generator, 8 is a keyboard, 10 is memory, 11 is monitor controller,
12 is a monitor.

Claims (1)

[Scope of Claims] 1. Video signal playback means having a variable speed playback function for controlling the playback of video signals at an arbitrary playback speed; first designation means for specifying the playback speed of the video signal playback means; and playback. a second specifying means for specifying a playback start position; and a speed information storage for storing a trajectory of change in playback speed specified by the first and second specifying means. A variable speed playback system for video signals, comprising: means for controlling the playback speed of the video signal playback means based on the content stored in the speed information storage means.