JPH0438076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape data search method suitable for use in automatically operating a videotape.
In particular, it is designed to be able to store accurate data.

Generally, to reproduce a large number of video tapes with the same content, one or two master video tape recorders (hereinafter referred to as VTRs) are used to copy the master tape.
Repeatedly play back multiple playback signals (for example,
100 VCRs). In order to operate such a duplicating device automatically, the positions of the start and end of the recorded portion of the master tape are stored in the control device, and this control device can also operate the master tape.
Controls VTR playback and rewinding. The positions of the start and end of the recorded portion are also represented by the count value of the control signal, but since there is a count error, it is not possible to accurately detect the editing point of the tape.

In view of this point, the present invention enables editing points to be accurately specified.

An embodiment of the tape data search method of the present invention will be described below with reference to the drawings.

In a helical scan VTR, a method is known in which the time code of the video track is recorded at frame intervals on a cue track along the length of the tape. FIG. 1 shows an example of such a time code, the SMPTE time code.
As shown in Figure 1, one frame consists of 80 bits (1 bit = 1/(80 x 30) sec), of which 64 bits are used as time code and user bits, and the remaining 16 bits are used as a synchronization word. It is. The time code part contains the time (×10 and ×
1), minutes (×10 and ×1), seconds (×10 and ×1),
Each data of frame (x10 and x1) is written. The space between these data is used as user bits. The 16-bit synchronization word consists of a 12-bit (all "1") synchronization signal and 2-bit direction determination signals "00" and "01" added before and after the synchronization signal. The direction discrimination signal is provided so that the time code reader can operate correctly regardless of whether the tape is running in the forward direction F or the reverse direction R.

FIG. 2 is a block diagram of a videotape duplicating apparatus to which the present invention is applied. This duplication device (printer) consists of two master VTRs 1A, 1B and multiple (for example, 100) copy VTRs 2a, 2b, 2.
It is equipped with c... Master VTR1A, 1B
A master tape or an original tape is wound on the VTRs, these VTRs are operated alternately, and the playback outputs are recorded in parallel on the copy VTRs 1a, 1b, . . . 24 for each VTR1a+1b...
Raw roll tapes corresponding to hours are wound, and the same content source is recorded multiple times on each roll tape by alternate operation of the two master VTRs 1A and 1B. After recording is completed, the roll tape is cut into pieces and wound into cassettes.

Immediately before the reproduction of one of the master VTRs 1A and 1B, for example A, ends, the other B begins reproduction operation, and when the reproduction of master A ends, it is switched to master B. Master A, which has finished playing, is rewound and waits until the next playback. The playback output of master VTRs 1A and 1B can also be switched using switcher 3.
The copies are sent to VTRs 1a, 1b, . . . The switcher 2 is controlled by a microcomputer 4, and an operation command signal is given to the microcomputer 4 from a console 5.

A time code writing/reading circuit 6 is connected to the master VTRs 1A and 1B, and lines 7a and 7
The time code of the editing point is recorded at the beginning of the tape via line 8a and 8b during playback. The write data is sent from the microcomputer 4 to the time code write/read circuit 6 via the data bus 9, and the read data and the time code during playback are sent from the write/read circuit 6 to the microcomputer via lines 10 and 11. It is sent to the computer 4. Edit point data and playback time code are processed by microcomputer 4.
is processed in the master VTR 1 via line 12 in the mode set in the console 5.
A, 1B are sent control signals, and line 1
A switching control signal is sent to the switcher 3 via the switch 3. The microcomputer 4 and the write/read circuit 6 are also coupled by a control line 14.
The microcomputer 4 includes a central processing unit 16 and
It is equipped with ROM17 and RAM18.

FIG. 3 is a circuit diagram of the time code write/read circuit 6 of FIG. This circuit 6 includes a SMPTE time code generator 19, which is well known in the art. The time code is generated by a counter 2 that counts the output of a clock circuit 20 in the generator 19.
Formed by 1. The time code formed for each frame is transmitted through the OR circuit 22 and the line 7a.
7b to the master VTRs 1A and 1B. Further, time code data indicating the editing point is sent from the microcomputer 4 to the data recording circuit 23 via the data bus 9, and further to the OR circuit 23.
2. Master VTR1 through lines 7a and 7b
A, 1B is supplied. The data recording circuit 23 is also operated by a control signal sent from the microcomputer 4 through the control line 14, whereby edit point data is written on the cue track at the beginning of the tape.

The time code outputs of the master VTRs 1A and 1B are supplied from lines 8a and 8b via the generator 19 to an identification circuit 24, where the time code during playback and the editing point data at the beginning of the tape are identified. The time code is sent from line 11 through microcomputer 4 to console 5 and displayed. Edit point data is also sent to the microcomputer 4 via line 10, where processing such as storage and comparison with playback time code is performed.
Based on this processing, control signals for the system are formed.

FIG. 4 is a front view of the operation console 5 of FIG. 2. FIG. 5 is a time chart showing the edit point data recording mode and a diagram showing the contents of the edit point data.

Knob 27 Master VTR1A, 1B in Figure 4
When this knob 27 is set to the zero point, the VTR 1A, 1B performs still playback, and by rotating the knob 27 in the F direction and R direction, the playback speed can be changed to any speed in the forward or reverse direction. can be played (from slow to fast). FIG. 5A shows the recorded contents of the master tape, in which a color bar 50 is recorded on the video track T ₂ for about 120 seconds from the beginning of the tape, and a 1 kHz reference signal 51 is recorded on the audio track T ₁ .
is recorded. After another 10 seconds of these color bars and reference signals, the video software 52 (master software or original software) to be duplicated
is recorded together with the audio signal. Furthermore, an SMPTE time code 53 is recorded on the queue track _T3 corresponding to each frame of the video track _T2 . Note that the SMPTE time code may indicate an absolute address with zero at the beginning of the tape, or may indicate real time when the software 52 is recorded.

By operating the manual key 28 shown in FIG.
1A or 1B can be placed in playback mode. In this state, operate the speed variable knob 27 and watch the video software 52 of FIG. 5A while looking at the monitor screen.
Detect the soft top t. At this time, when the memory in key 35 (KEY IN) shown in FIG. 4 is operated, the system shown in FIG. 2 goes into memory mode. When the soft top key 36 is further operated, the time code at the soft top t changes to the writing/writing shown in FIG.
The data is written to the RAM 18 in the microcomputer 4 through the read circuit 6. Note that the time code of the soft top is displayed on the display section 37 of the console 4. After that, perform the same operation and press the soft end key 38 to open the video software 5.
The time code at the end (soft end) of 2 is
Written to RAM18. Also video software 5
If there is an edit instruction point at the intermediate point of 2, the time code of this edit point is written into the RAM 18 by operating the soft edit key 39. In Fig. 4, among the operation mode keys 30 to 34, the standby key 30 is the master VTR 1A.
Or the operation key to rewind 1B and make it playable, and the shuttle key 34 is the master key.
This is an operation key for operating the VTRs 1A and 1B alternately.

When the memory input is completed, the check key 40 is operated, thereby confirming the timing of sending out the software during duplication. When the code recording key 42 is operated after the check is completed, the system enters the code recording mode. In the code recording mode, first convert the standard speed from the soft top t in Figure 5A.
The master tape is fast-forwarded in reverse to a position 90 seconds earlier, and from this position the recording mode is switched to standard speed. Code recording is performed in a 30 second period, during which a zero reset pulse b shown in FIG. 5B is sent from the microcomputer 4 through the control line 14 as shown in FIG. supplied to the input. As a result, the time code output of the counter 21 becomes zero, and the data of frame 0:00:00:00 is recorded on cue track _T3 of the tape.

On the other hand, when the code recording mode is entered, a data transfer pulse c shown in FIG.
Edit point data such as soft top and soft end stored in the RAM 18 is transferred to the data recording circuit 23 in FIG. 3 via the data bus 9. The data recording circuit 23 converts the input data into SMPTE time code and outputs the OR circuit 22 and lines 7a and 7b.
to the master VTRs 1A and 1B.
This code is sent by the microcomputer 4.
The recording start pulse d of approximately 6 msec width shown in FIG. 5D is generated at . This start pulse d is generated at a position approximately 15 seconds from the start point of the code recording mode, and is generated on the control line 14 as shown in FIG.
The data is sent to the data recording circuit 2 through. As a result, as shown in FIG _.
0 data D ₀ is recorded for a period of 15 seconds, then edit point code data Dc is recorded, and then 0
Data is recorded for a period of approximately 13 seconds. Note that the 0 data _D0 is the code output (0:00:00:00 frame) with the counter 21 reset as described above, but this may also be a code of all "1"s.

FIG. 5F is an enlarged view of the code recording portion shown in FIG. 5E. As shown in FIG. 5F, soft top data and soft end data are recorded in the code recording portion Dc. Each data area is divided into five blocks _B1 to _B5 , and the same data is written in each block. When these code data are read and written into the memory RAM 18 of the microcomputer 4 during tape duplication, only when it is confirmed that, for example, three data matches among the five reproduction signals of the same data, are they written to the memory as official data. I try to include it. This increases the reliability of data reading.

FIG. 5G is an enlarged view of one block in FIG.
The soft top or soft end time code corresponding to the fourth frame of minutes and 16 seconds is written in the code format shown in FIG. In addition, the (x10) time (4 bits) digit _H10 of the time code shown by the hatching in Fig. 5G has a maximum of 1.5
Since it is about the time, without entering the time code,
Contains an identification signal for video software. If multiple video sources are recorded on one master tape, the code data Dc shown in Figure 5F
A plurality of video sources are recorded, and in this case, a signal (code) for identifying each video source is written in the most significant digit _H10 . Note that instead of this identification signal, data indicating the editing time width may be written.

Next, the operation of multiple tapes will be explained. Fourth
When the auto mode key 43 of the operation console 5 shown in the figure is operated, the system enters an automatic operation state, and the video software 52 of the master tape is repeated based on the soft end data and soft top data stored in the RAM 18 of the microcomputer 4. and the playback signal is sent to the copy VTR 2a, 2b.
It will be sent to... The master VTRs 1A and 1B are alternately in playback mode, and while one is playing, the other is in standby. The recording section of the video software 52 is detected by comparing the soft top and soft end data with the reproduced SMPTE code, and when a match is detected, the microcomputer 4 starts the master VTR 1A, 1B. Various control signals such as rewind are sent. Soft duplication is a copy
This process continues for about 24 hours until the raw roll tape of VTR2a, 2b... is used up.

In this case, in this example, the fifth
A master tape on which a code as shown in the figure is recorded is loaded into the master VTRs 1A and 1B, and first the tape is moved to the vicinity of the soft top by manual operation, and then the search key 14 on the console 5 is operated.
When this search key 44 is operated, it operates as shown in the flowchart of FIG. That is, when the search key 5 is operated, the system enters the search mode, clears the time code work area, clears the flag, displays the search mode, and sets the VTRs 1A and 1B to standby. next
Set VTR1A and 1B in reverse mode, return 90 seconds in standard speed, and then read the time code in reverse mode. In this case, “0” data is sampled at regular intervals and detected five times, and data “0” is detected five times.
When it is detected three times, it is detected three times that the (×10) time (4 bits) digit _H10 of the time code, which is an identification signal, is not “0” and at the same time, the (×10) time (4 bits) of the time code, which is an identification signal, is detected. 4 bits) digit H ₁₀
It is detected that is not "0" and that the following 7 digits of the code are not all "0". When the above-mentioned detection is made, it is determined that this part is the part where the data code is recorded, and the reverse is further performed for a predetermined second, for example, 20 seconds in terms of standard speed. After that VTR1A,1
Stop B, then put it into playback mode, read the code of the identification signal of digit _H10 , and if the code of the identification signal recorded 5 times matches 3 or more times, this data code is recognized as the correct data code and is sent to the microcomputer 4. It is stored in the RAM 18 of. After storing this, the time code of the soft top is read out and displayed, the time code of the soft end is read out and this soft end is displayed, and the type of software is determined from the identification signal and the type of this software is displayed. At the same time, the playback position of the tape is located, and a message indicating that the search has been completed is displayed. Thereafter, the automatic tape duplication operation described above is performed. When detecting a code recording part in search mode, the code data Dc described above is used.
The 0 data D ₀ written before and after acts as a data sink. 0 data D ₀ is code data
Since it is inserted before and after Dc, the recording position of code data Dc can be detected whether the tape is fed backwards or forwards. Furthermore, if the time code write/read circuit 6 is controlled by the data sink (0 data), malfunctions such as reading time codes other than the code data recording area can be prevented. The code data Dc (edit point data) and the time code corresponding to each recording field are
It is identified by the identification circuit 24 shown in the figure.

In addition, on the operation console 5 in FIG. 4, operate the auto mode key 43 and then press the print start key 4.
7, edit point data (soft top, soft end) and master VTR1A,
The operating mode of 1B, etc. are displayed by a printer (not shown). In this case, the duplication operation continues until the prescribed number of recordings specified by the daisy switch 48 is completed. When the mode clear key 46 on the console 5 is operated, the specified mode (auto, manual, memory in, search, etc.)
is cleared. Further, when the emergency stop key 45 is operated, the entire system is suddenly stopped.

In the above example, the time code is
Although SMPTE timecode was used, other timecodes such as EBU timecode (European type) could also be used.

As described above, the present invention detects the data code while the tape is in the reverse state, then reverses for a predetermined period of time, and then searches for data in the playback state, so it is possible to search for accurate data on the tape. Furthermore, according to the present invention, since a plurality of identical data are recorded and their coincidences are detected, correct data can be read. Furthermore, according to the present invention, since data "0" or "1" is recorded for a predetermined period before and after the data, data can be read easily and reliably. Furthermore, since the data is recorded in the same format as the SMPTE time code, a special signal generator for this recording is not required, which simplifies the circuit configuration.
Since the most significant digit _H10 of the time code is used as a data identification signal, it is easier to handle than using a user's code. Furthermore, when the present invention is used in a printer as in the above-mentioned example, it is possible to specify editing points very accurately, which has the advantage of enabling good automatic operation.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the contents of the SMPTE time code, Fig. 2 is a block diagram showing an example of a videotape duplicating device using an example of the tape data search method of the present invention, and Fig. 3 is a diagram showing the contents of the SMPTE time code. A configuration diagram showing an example of a time code writing/reading circuit, FIG.
FIG. 5 is a time chart showing an example of data recording contents and a recording process, and FIG. 6 is a diagram for explaining the present invention. 1A and 1B are master VTRs, 2a and 2b respectively
... 2f is a VTR for copying, 4 is a microcomputer, and 5 is an operation console.

Claims (1)

[Claims] 1. A time code indicating a predetermined position on the tape is recorded corresponding to each diagonal track, and the time code is recorded in each of a plurality of blocks, including code data indicating an editing point and code data before and after the code data. A tape having data "0" or data "1" recorded over a predetermined period of time, and in which an identification signal for identifying the video software is recorded in the uppermost digit of each of the blocks. In the method of searching for data, the tape is rewound by a playback device, the data "0" or the data "1" is detected, the identification signal is detected after such detection, and the identification signal is detected. After the detection, the tape is rewound for a predetermined period of time to be in a stopped state, and then switched to a playback state and the identification signal is detected a plurality of times, and when the detected identification signals match each other more than a predetermined number of times, the detected identification signal is detected. A method for searching data on a tape, characterized in that code data including a signal is stored by the reproducing device.