JPH0817027B2 - Frame search device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is more desirable than a video signal (video signal) in frame units reproduced from a helical scan type magnetic recording / reproducing apparatus such as a video tape recorder. The present invention relates to a frame search device for searching the above frames, and more particularly to a frame search device suitable for additional use in a video printer.

(Technical background) In recent years, a video printer that prints and outputs an image from a video tape recorder (VTR) or a television receiver (TV) has been researched, developed, and commercialized. As shown in FIG. 11, this video printer converts a video signal supplied from a VTR or TV into digital data, and temporarily stores the data for one frame (consisting of two feeds) in a frame memory. . Next, the data is sequentially read from the frame memory line by line (returned to an analog signal), and an image for one screen is printed on the recording paper by the printing means.

That is, the video signal is composed of two fields for one frame, that is, one screen, the operating speed of the printing means is extremely slow compared to the transmission frequency of the video signal, and the video signal is a composite signal. Is necessary for printing by separating it into a luminance component and a color component.
From the viewpoint of generating R, G, B signals, etc., the video printer is provided with a frame memory as described above.

Then, while monitoring images (moving images) that are continuously reproduced, a desired frame is searched for and the image is taken into the frame memory (as a still image) by operating a write switch or the like.

(Problems to be solved by conventional techniques and inventions) As frame search methods, (a)
In the VTR, a VITC signal (frame address signal) is additionally recorded to the video signal, and at the time of reproduction, the frame data of the image is searched by the address data obtained from the VITC signal.

On the other hand, adding the VITC signal function to a consumer VTR used in a general household cannot be adopted because it increases the cost. In addition, since it is necessary to add a VITC signal to a magnetic tape that has already been recorded and rerecord it, it takes time and trouble, and the image also deteriorates.

(B) It is also possible to search for a desired frame by a reproduction method such as so-called frame advance / still (still). However, in an image obtained by a reproduction method such as frame advance or still (still), the inclination of the track during recording differs from the inclination of the head scan during reproduction, as is clear from the explanatory diagram shown in FIG. Therefore, only an image with poor image quality containing noise can be obtained.

Therefore, a desired frame is searched while monitoring a moving image obtained by normal reproduction, but the timing of loading into the frame memory is difficult and the search accuracy is extremely poor.

(Means for Solving the Problems) A desired frame is searched for from a frame-unit video signal reproduced by a helical scan type magnetic recording / reproducing apparatus in which a control pulse is recorded in a longitudinal direction of a magnetic tape, and is stored in a frame memory. A frame search device for storing and displaying and outputting the stored video signal on a monitor, and a means for rewriting the duty ratio of a control pulse on a magnetic tape as a reference point and a frame number from the reference point. A predetermined amount of magnetic tape is wound according to the means for measuring, thinning out the video signals of a plurality of consecutive frames and storing them in the frame memory, and the means for displaying as a multi-screen, and the search switch operated in the desired frame. A method to return and automatically set the reference point to a position before the desired frame, and a method to set the reference point from the set reference point. A means for thinning out a plurality of consecutive frames, storing them in a frame memory, and displaying them as a multi-screen so as to include the frame in which the search switch is operated while measuring the number of frames.
A means for generating a search frame number from the set reference point to the selected frame while selecting a desired frame from the displayed multi-screen, and rewinding the magnetic tape, and a video signal of the search frame number from the reference point. The present invention provides a frame search device characterized by comprising means for storing as a mono screen in a frame memory.

(Embodiment) An embodiment of the frame search device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a structural diagram showing an example in which the frame search device is realized by a system controller (microcomputer) and is added to a video tape recorder.

 First, the configuration of the frame search device will be described.

Reference numeral 1 is a video tape recorder (hereinafter referred to as VTR) to which a frame search device is added. Video signals are recorded / reproduced on the magnetic tape by the well-known helical scan method, and audio signals and audio signals are recorded in the longitudinal direction of the magnetic tape. A control signal (control pulse) is recorded / reproduced. Reference numeral 2 denotes a system controller (for example, a microcomputer, hereinafter referred to as a syscon) that executes the operation of the frame search device, and has an input port group In and an output port group On. By the mode switch Sm on the VTR1 side,
When the normal mode is switched to the frame search mode, the VTR1 enters the control of the syscon 2, and the control signal from the output port of the syscon 2 causes the VTR1 to play / pause / stop.
Performs operations such as rewind, fast forward, and reverse playback (search). Further, the control pulse from the VTR 1 is input to the pulse detectors 3a and 3b, and the presence / absence (and duty ratio) of the control pulse is input to the syscon 2. Furthermore, the control signal of the VSC1 is rewritten by the control signal of the syscon 2 (for example, VTR1
When the VISS terminal and the MARK terminal on the side are turned on, the VISS signal described later is written).

On the other hand, the reproduction signal from the VTR 1 is input to the A / D converter 6 after passing through the LPFs (low pass filters) 4a and 4b and the mode switch 5. The video signal digitized by the A / D converter 6 is written into the (frame) memory 7, sequentially read out, input to the D / A converter 9 via the switch 8, and again analogized, The data is output to the monitor 10 and a printing device (not shown). Reference numeral 11 controls an address at the time of writing and reading of the memory 7 to create a (divided) multi-screen of video signals (hereinafter, a multi-screen of 3 vertical × 3 horizontal = 9 multi-screen will be described as an example). ) Control circuit.

When writing to the memory, the control circuit 11 uses the frame pulse fp from the frame detector (V DET) 12 and the horizontal sync pulse from the horizontal sync signal separator (HDET) 13 as a reference P
A clock CK (a clock having a frequency corresponding to 4f when the color image carrier is f) generated by the LL circuit 14 and a horizontal pulse Hd are input.

Further, in the control circuit 11, at the time of memory reading, the PLL circuit 14 based on the reference signal from the crystal oscillator 15 having the same frequency as the horizontal synchronizing signal, the clock CK generated by the frequency divider 16, the horizontal pulse Hd, Each frame pulse fp is input. Clock CK is AD converter 6 and DA converter 9
It is also the clock of. It should be noted that the switching of the clock at the time of writing and reading of the memory is switched by the switches 17a and 17b controlled by the mechanical controller 2.

Further, a control signal for switching between the mono screen and the multi screen from the mechanical controller 2 is output to the changeover switch 5 of the control circuit 11 and the screen switch 8 for switching the signal from the memory 7 of the video signal from the VTR 1 is also controlled by the syscon 2. ing.

Further, the search switch S _{1 which} will be described in detail later is provided on the system controller 2.
・ S ₂ , keyboard K for inputting numerical values is connected. The output of the frame detector 12 is input to the counter of the syscon 2 so that the number of frame pulses can be counted.

 Here, the control pulse of VTR1 will be described.

Fig. 4 shows the magnetic tape format of the helical scan type VTR. An inclined video track 112 is formed on the magnetic tape 111, an audio track 113 is formed on the upper side in the longitudinal direction, and a control track 114 is formed on the lower side in the longitudinal direction.

A control pulse is recorded on the control track 114. The control pulse is a 30 Hz pulse synchronized with the fall of the vertical synchronizing signal of the input video signal as shown in FIG. 5, and is recorded on the magnetic tape 111 at the same time as the video / audio signal. At the time of reproduction from the magnetic tape 111, the control pulse is also reproduced at the same time, the rising portion of the pulse is detected, and it is used for tape feed phase control (servo control).

Furthermore, due to the falling edge of the control pulse,
By changing the duty ratio as shown in FIGS. 6 (A) and (B), the control pulse with a duty ratio of 60% is used as “0” pulse data and the control pulse with a duty ratio of 27.5% is used as “1” pulse data. , It is also used to insert the cue data of the magnetic tape 1.

As a (positional) reference signal using such data, there is already the VISS format as shown in FIG.

A control pulse (that is, data "0") having a duty ratio of 60% has already been written in the control track on the magnetic tape on which the video signal is recorded. The rewriting of the control pulse is to rewrite only the falling portion of the control pulse while reproducing the rising portion of the control pulse for use in servo control.

That is, when the syscon 2 turns on the VISS terminal and the MARK terminal of the VTR 1, the VISS signal is superimposed on the magnetic tape. The write signal to the magnetic head when the VISS signal is superimposed is input to the detector 3b as a REC control pulse,
By the output of the detector 3b, the write timing of the VISS signal is sent to the syscon 2.

During normal playback, the control pulse demodulated by VTR1 is input to the detector 3a, and the output of this detector 3a outputs "0", "1" data based on the control pulse number and the duty ratio of the control pulse. Syscon 2
And the VISS signal during normal playback is detected. Further, VISS signal detection pulse during reverse playback is sent from VTR1 VISS DET to syscon.

When using the VISS signal as the reference signal,
Even if the entire signal is used, only a part of the VISS signal (for example,
61 32nd) may be used.

In the control circuit 11 configured as described above, the memory 7 is operated at the timings shown in FIGS. 8 (A) and (B) and FIG.
Writing / reading to / from is performed as shown in Fig. 10.
9 (divided) multi-screens for 9 frames of F _{1 to} F ₉ are created.

(Writing / reading in mono screen) In mono screen, 4f clock CK is used as a writing / reading clock, and addresses are sequentially given by the count value of horizontal pulse Hd and the number of clock CK from horizontal pulse Hd. The write / read timings are the same, and one frame (two fields) of data from the VTR 1 is written to and read from the memory 7.

(Writing in 9-division multi-screen) At this time, as shown in FIGS. 8 (A) and 8 (B),
The write clock is (1/3) .multidot.4f, and the write timing signal is generated once between the three horizontal synchronizing signals to write to the memory 7 every two horizontal lines. In the memory 7, the video signal from the VTR 1 is thinned out by 1/3 in the horizontal and vertical directions, and in the area of 1/9 of the memory in the order of the arrows (a ₁ → b ₁ → a ₂ → b ₂ … → a ₉ → b ₉ ) Continuous video signals for 9 frames are written for 1 frame (2 fields) in the memory 7.

In addition, when an m × n multi-screen is used, the write clock may be set to 1 / m and writing may be performed every n−1 horizontal lines.

(Reading in 9-division multi-screen) As shown in FIG.
It is read out in the order of arrows (the first line of a ₁ → the first line of a ₂ → the first line of a ₃ → the second line of a ₁ ... the last line of b ₉ ) and as shown in FIG. A multi-screen (from F ₁ to F ₉ ) is played on monitor 10.

The operation of the frame search device configured as described above will be described. First, the operation will be described with reference to FIGS. 2 and 3. FIG. 2 is a flow chart showing the operation of the frame search device executed by the system controller, and FIG. 3 is an explanatory diagram showing the operation of the video tape recorder by the frame search device.

Becomes the search mode, the operator searches the vicinity of the desired frame manually, in the normal playback operation Once reached the vicinity of the desired frame, the setting switch and ON the S ₁ (step
100-103). One frame immediately after the setting switch S ₁ is turned on is written in the memory 7 as a mono screen, the VTR 1 is temporarily stopped, and the mono screen in the memory 7 is immediately read out and reproduced on the monitor 10 (steps 104a to 104a). 106).

Here, when the reproduction screen is near the desired frame, the search is started, and when the search switch S ₂ is turned on,
The VTR 1 is rewound by a predetermined amount, then temporarily stopped, and then resumes normal reproduction. Two to three seconds after the normal reproduction is started, when the servo rides and an accurate frame pulse is obtained, rewriting of the control pulse (duty) is started (steps 200 to 250a).

Data “0” is superimposed on the control pulse to prevent erroneous detection, followed by superimposing a VISS signal (61 pieces of data “1”) as a reference signal, and thereafter, superimposing data “0” (step 205b). ). Duty (du
ty) When a change point is detected, counting of frame pulses n _X is started, and video signals for 9 consecutive frames are repeatedly written in the memory 7 (steps 206a to 207).
When the predetermined count number is reached, the writing is stopped, the screen in the memory 7 is read and reproduced as a multi-screen on the monitor, and the VTR 1 is temporarily stopped (steps 208 to 211).

Here, the operator determines whether or not there is a desired frame in the multi-screen (steps 300 to 302).

If there is a desired frame, the frame number is input (steps 302 and 304). A new search frame pulse number n _X according to the input frame number value b is generated (steps 305 to 307). The VTR1 is rewound again, detects the reference signal, then pauses, starts normal playback, and receives a frame pulse n _X from the reference signal (duty change point) according to the value of the frame number. Is written in the memory 7 (when the flag m = 0), and the desired frame written in the memory 7 is sent to a printing device or the like (steps 400 to 409). Return to step 300.

If there is no desired frame, move the block or make a frame sheet. When it is determined that the desired frame is around several frames, the frame is shifted (steps 300, 313 to 317), and when it is determined that the desired frame is around several tens of frames, one block is set to 9 frames. Moves as a block (steps 301, 308 to 312).

When the block movement amount a and the frame shift amount d are input, the VTR1 is rewound again, and after detecting the reference signal,
The video signal for 9 consecutive frames is generated after a new search frame pulse n _X corresponding to the block movement amount a and the frame shift amount b input from the reference signal (duty change point) Written in the memory 7 (when the flag m = 1), monitor as a multi-screen
Played on 10. It is again judged whether or not there is a desired frame in the multi-screen (steps 400 to 409).

When the frame set by the block movement amount a and the frame shift amount d is positioned before the reference signal (that is, when n _X ≧ 0 is not satisfied), (steps 312, 31
7), the reference signal is newly rewritten before the setting frame, and the same multi-screen writing is performed (steps 500a to 510).

Based on the outline of the operation described above, the operation of the frame search device, in particular, the amount of movement will be described in detail with reference to FIGS. 3 (A) and 3 (B).

Note that the frame search device counts the number of control pulses and the number of frame pulses as a method of detecting the relative position (movement amount) on the magnetic tape. Hereinafter, the control pulse number is indicated by (n) and the frame pulse number is indicated by [n].

(Operation [Steps 100 to 106]) As shown in FIG. 3 (A), the switch S ₁ is pressed in the playback state of the VTR _1, and the video signal of one frame is stored in the frame memory 7 at that timing, and then the control pulse Start counting, put VTR1 in pause mode, detect VTR1 standstill, and store the count value of control pulses. Let this be (n ₄ ). If the time from one control pulse to the next control pulse exceeds a certain time, VTR1 is considered to be stationary.

(Operation Step 200-203]) If S ₂ is ON, VTR 1 is the reverse reproduction (search) mode, starts counting the control pulses. The count value, after a _{(n 4 + X + X +} 9l + n y), starts counting the control pulses again, after detecting the stationary and pause mode VTR 1, and stores the count value. Let this be (n _Z ). In addition, multi 9 to be taken in
The value of X is set to 4 to 5 so that it can be obtained in the middle of the screen, that is, the fifth screen.

(Operation [Steps 204 to 211]) Set VTR1 to playback mode, start counting control pulses, and after (n _Z + n ₅ ) counting, start rewriting the control pulse duty and write "0". Here, n ₅ is the number of pulses until the servo rides and an accurate frame pulse is obtained, and is set to 90 here. After rewriting is started, (n ₇ ) = 30 counts, and then detection of whether or not the duty of the control pulse during recording changes is started. Furthermore, after rewriting is started (n ₆ )
= After counting 60, change the duty amount and write "1" 61 times continuously. On the other hand, the timing at which this duty change point is detected, the frame pulse count of the reproduced video signal is started with reference to it, and the timing is synchronized with the frame pulse after the number of control pulses (n ₀ ) (hereinafter referred to as t ₀ Calling) repeatedly writes the multi-screen to the memory 7, and stops writing to the memory 7 at the timing when the writing after 9 (l + 1) frames from the timing t ₀ ends (for example, l = 9),
After counting frame pulse [n ₁ ], stop counting,
Store the count value. Let this be [n _X ]. After counting the control pulse (ng), stop rewriting duty and stop VTR1. In addition, [n ₁ ] is an adjustment value of the control pulse and the frame pulse, and is 1, for example.
If there is a VISS signal in this part, and n _g is the desired frame earlier than this in the subsequent search by block transfer, _ng will mistakenly detect the VISS signal in this part during the search. This is to prevent this, and it is set to 80 frames.

(Operation [Steps 303 to 307, 400 to 401]) When a desired frame is present in the multi-screen, a frame is selected. When the desired frame in the multi-screen is the b-th, the set value b is input. [N _X ] ← [n _X -9
-N ₁ + b], VTR1 is rewound, and step 205a
(Or step 504a described later) detects the Duty change point rewritten and starts counting the control pulse from that point, and after counting (n ₅ + n ₆ −n ₇ ) again, starts counting the control pulse again, Put the VTR1 in pause mode,
After detecting the static of VTR1, the count value of control pulse is stored. Let this be (n _Z ).

Control pulse counting is started again, and after (n _Z + n ₅ ) counting in playback mode, Du
Start detecting the change point of ty.

The duty change point is detected, the frame pulse count of the reproduced video signal is started based on the detected duty change point, and the desired one frame is stored in the memory 7 after the number of frame pulses reaches [n _X ].
Is written to and output (when m = 0).

(Operation [Steps 300, 313 to 317, 301, 308 to 312]) If there is no desired frame, block movement or frame shift is performed. When it is determined that the desired frame is around several frames, the frame is shifted, and when it is determined that the desired frame is around several tens of frames, the block is moved with 9 frames as one block.
The block movement amount a and the frame shift amount d are input.

When moving blocks, [n _X ] ← [n _X -9-n ₁ -9x
It is a a], when the frame _{shift, [n X] ← [n} X -9
-N ₁ + d].

When the new n _X is n _X ≧ 0 (when there is a destination after the reference signal, steps 400 to 409), reverse reproduction is performed in the same manner as the above-described operation,
The duty change point rewritten in 205a is detected, control pulse counting is started from that point, and after (n ₅ + n ₆ −n ₇ ) counting, control pulse counting is started again.
The VTR1 is set to the pause mode, and the count value of the control pulse is memorized after detecting the static of the VTR1. Let this be (n _Z ).

The control pulse counting is started again, this time after (n _Z + n ₅ ) counting in the playback mode, detection of the Duty change point of the control pulse is started. The duty change point is detected, the frame pulse count of the reproduced video signal is started with reference to the duty change point, and after [n _X ] is reached, the multi-screen is written in the memory 7 (m = 1).

When the new n _X is not n _X ≧ 0 (when there is a destination ahead of the reference signal, steps 500a to 519), as shown in FIG. 3 (B), during reverse reproduction (search),
The Duty change point rewritten in step 205a is detected, control pulse counting is started from that point, and after a certain number of pulses (Y ₀ = 9l + n _y ) have been counted, VTR1 is set to the pause mode. Stop the control pulse counting after the VTR1 is stopped. Let this count value be (n _Z ). Counting of the control pulse is started again, this time, after the constant number of pulses (n _Z + n ₅ ) is counted in the reproduction mode, the duty of the control pulse is started to be rewritten (n ₆ ), and then a new VISS signal is superimposed. Detect the Duty change point and use it as a reference
Start counting the frame pulse of the playback video signal,
Take in the _{[9l + n 0 + n X} ] count after the multi-screen. The process moves to step 300 to search for a desired frame.

Although the number of frame pulses from the frame detector 12 is used as the count value from the reference signal in the above embodiments, the number of control pulses from the detector 3a may be used.

Further, the frame search device such as the system controller 2 and (frame) memory 7 may be built in the VTR 1, a printing device (printer) not shown, or an adapter interposed between the two. If built in the printing device,
The (frame) memory 7 can also be used as a buffer memory of the printing apparatus.

(Effects of the Invention) As described in detail above, according to the frame search device of the present invention, an arbitrary frame of a VTR playback video signal is searched and extracted from the normal playback state without making the VTR still playback. Since it can be stored in the memory, the video signal of the desired frame can be reliably and accurately searched.

Furthermore, the reference point is automatically set according to the search switch operated in the desired frame, and the multi-screen is displayed to include the frame in which the search switch is operated so that the search can be performed. A desired frame can be easily obtained by referring to the multi-screen.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a frame search device according to the present invention. FIG. 1 is a block diagram showing an example in which the frame search device is realized by a system controller (microcomputer) and added to a video tape recorder. 3 is a flowchart showing the operation of the frame search device executed by the system controller, FIGS. 3A and 3B are explanatory diagrams showing the operation of the video tape recorder by the frame search device, and FIG.
FIG. 7 is a diagram for explaining the control pulse, FIGS. 8 (A) and (B), FIG. 9 are diagrams for explaining the control circuit of the memory, FIG. 10 are diagrams showing a multi-screen, and FIG. Is a diagram showing a conventional example, and FIG. 12 is a diagram explaining conventional problems. 1 ... video tape recorder (VTR), 2 ... system controller, 7 ... (frame) memory, 11 ... control circuit.

Claims (1)

[Claims] 1. A desired frame is searched for from a video signal of a frame unit reproduced by a helical scan type magnetic recording / reproducing apparatus in which a control pulse is recorded in a longitudinal direction of a magnetic tape and stored in a frame memory. A frame search device for displaying and outputting a stored video signal on a monitor, a means for rewriting a duty ratio of a control pulse on a magnetic tape as a reference point, and a means for measuring the number of frames from the reference point. , A means for displaying a multi-screen while thinning out video signals of a plurality of consecutive frames and storing them in the frame memory, and rewinding the magnetic tape by a predetermined amount according to the search switch operated in the desired frame A method to automatically set a reference point at a position before the frame, and to measure the number of frames from the set reference point At the same time, a means for thinning out a plurality of consecutive frames and storing them in the frame memory and displaying them as a multi-screen so that the search switch includes the operated frame, and selecting a desired frame from the displayed multi-screens. , And means for generating the number of search frames from the set reference point to the selected frame, and means for rewinding the magnetic tape and storing the video signal of the number of search frames from the reference point in the frame memory as a mono screen. A frame search device characterized by the above.