JPS63245078A - Still picture recording system - Google Patents

Abstract

PURPOSE:To prevent the degradation in use efficiency of a recording area and to simplify control procedures by adding frame numbers, which correspond to recording positions of two-field units of a video signal forming a still picture, and still picture identification codes to every 2n-number of fields. CONSTITUTION:Since frame numbers C1 and C2 corresponding to recording position of two-field units of the video signal forming a still picture and disk codes D1-D4 consisting of still picture identification codes are added to every 2n-number of fields, search and jump for still picture reproducing are performed with the single code. Thus, a digital data multiplex area in the vertical blanking period is not narrowed and switching to search based on the still picture code is unnecessary in the case of search, and the still picture reproducing operation is easily controlled.

Description

TECHNICAL FIELD The present invention relates to a still image recording method, and more particularly to a method for recording a video signal forming a still image every 2n (n is a natural number) fields.

BACKGROUND TECHNOLOGY MUSE (Multiple Sub
-Nyquist Sampling Encodln
A method called g) has been proposed. According to this MUSE system, it is also easy to record high-quality television signals onto a recording medium such as an optical video disc.

In this MUSE method, subsampling is performed in a cycle of four fields, so one still image is formed by four fields, that is, two frames.

Therefore, the conventional method for recording MUSE signals for four fields forming a still image on a disk is to give a common picture number to each field of the MUSE signals for four fields, and then to Japanese Unexamined Patent Publication No. 191590/1983 discloses a method in which a still image identification code is formed with a subcode that identifies each field from the other three fields, and this code is inserted and recorded in the MUSE signal field by field. Disclosed.

In such conventional recording systems, when still images and moving images are recorded on the same disc, a frame number is added to each frame of the moving image to enable searches, etc., so this frame number code and The still image identification code must be switched and recorded for each field, or both must be recorded together. In the former method, when searching for still images, it is necessary to switch the procedure to a search by picture number. However, the latter method has the disadvantage that the recording area is used inefficiently.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent a decrease in recording area usage efficiency even when a moving image and a still image are recorded on the same disk,
Another object of the present invention is to provide a still image recording method that can simplify control procedures.

The still image recording method according to the present invention is characterized in that a still image identification code is added together with a frame number corresponding to the recording position every two fields of a video signal forming a still image every 2n fields.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, a high-quality television signal edited on a videotape or the like with a mixture of moving images and still images or both is reproduced and input to a MUSE encoder 1. M.U.
The SE encoder 1 compresses and multiplexes two chrominance signals of a high-definition television signal alternately in one line during the horizontal blanking period of a luminance signal, and then shifts the phase of a 16.2 MHz sampling clock by π/2 for each field. By performing sampling at sample points at different positions for each field and inserting various control signals necessary for sample synthesis processing in the MUSE decoder, the bandwidth is 8.1M.
A Hz video transmission signal (MUSE signal) is derived.

Meanwhile, from the videotape, Time Food is played along with a high-definition television signal. In addition, 2 that forms a still image
When a frame is input to the MUSE encoder, a still image identification code is input to the disc code generator 2 together with the time code from an external controller or the like.

The time code is a code that indicates hours, minutes, seconds, and a frame number within one second.The disc code generator 2 generates a frame number code corresponding to this, and generates a disc code that is configured together with the still image identification code. Derived for each frame.

The frame number code may indicate hours, minutes, seconds, and a frame number for one second like a time code, or it may be converted into a frame number. Further, the still image identification code includes a code indicating that the frame is one of two frames constituting the still image, and a code indicating whether it is the first frame or the m2 frame.

The disk code derived as above is the multiplex circuit 3
Thus, each frame is multiplexed onto a predetermined line of the output of the MUSE encoder 1 within the vertical blanking period preceding the frame. Furthermore, digital data such as PCM audio data is multiplexed into the empty portion of each field vertical blanking period.

The structure of the portion corresponding to one still image in the output of the multiplex circuit 3 is as shown in FIG.
The first and third fields of the two fields each contain a disc code CI%C2 consisting of a frame number code and a still picture identification code, and digital data D Is such as PCM audio data.
Each of D3 and the video signal are arranged in sequence. Also, 2
Each of the 4th and 4th fields contains digital data D.
2, D4 and the video signal are arranged in sequence.

In FIG. 3, FI and F2 indicate two consecutive frames of video signals forming a still image, and f1 to f4 indicate four consecutive fields of video signals forming a still image. Further, VB indicates a vertical blanking period, ■ indicates a two-track jump start position during still image reproduction, and ■ indicates a two-track jump end position.

The output of the multiplex circuit 3 is supplied to an FM modulation circuit 4. F
In the M modulation circuit 4, the carrier of a predetermined frequency is frequency-modulated by the output of the multiplexing circuit 3. FM modulation circuit 4
The FM signal output from the is supplied to the optical modulator (not shown) of the video disc recorder, and the light is irradiated onto the recording surface of the disc, which is rotated at a frame period and transported at a predetermined speed in the radial direction. The intensity of the beam is modulated.

As a result, the MUSE signal is recorded on the spiral track of the disk.

Incidentally, since the video disc recorder is well known, the explanation thereof will be omitted.

The track on the disc recorded in this way is the third
They are arranged as shown in the figure. Symbols C1, C2, Dl~
Da, FI, F2, f+ to f1 all indicate track portions corresponding to the symbols in FIG. Third
As is clear from the figure, since each still image code is multiplexed on a predetermined line within the vertical blanking period, the recording positions are aligned in the radial direction.

Next, a reproducing apparatus for reproducing still images from a disc obtained in this manner will be explained with reference to FIGS. 4 and 5.

In FIG. 4, the disk 11 is rotated by a motor 12 at a constant rotation speed of approximately 1800 rps (C frame period). An RF (high frequency) signal is read from the disk 11 by a pickup 13 . The position of the information reading light spot of the pickup 13 is controlled in the radial direction by a tracking servo mechanism 14 so as to track the track of the disk. The tracking servo mechanism 14 causes the optical spot of the pickup 13 to jump in response to a command supplied from the system controller 15 in a special playback mode that requires a jump operation (track skipping operation) such as still image playback.

The RF signal read from the disk 11 by the pickup 13 is amplified by the amplifier 16 and then converted to FM.
The signal is supplied to the demodulation circuit 17 and converted into the original MUSE signal. This MUSE signal is sent to a high-definition television receiver or the like.

On the other hand, the MUSE signal is also supplied to the disc code reading circuit 18, and the disc code is read. Reading is performed using the disc code's own synchronization timing or the MU
This is done based on the synchronized timing of the SE signal. The output of this disc code reading circuit 18 is supplied to the system controller 15. Commands corresponding to key operations on the operation unit 21 are also supplied to the system controller 15 . The system controller 15 includes, for example, a processor, a ROM,
It is formed by a microcomputer consisting of RAM, etc. Each part of the system controller 15 is controlled by a processor that operates according to a program stored in the ROM in advance.

The operation of the processor in the system controller 15 will be explained with reference to the flowchart in FIG.

When the frame number of the first frame forming a desired still image is specified during execution of a main routine, etc., and a still image playback command is issued, the processor moves to step S1, starts a reading operation, and reads the disc. Read the frame number in the code.

Next, the processor moves to step S2 and determines whether the read frame number matches the target frame number. If it is determined in step S2 that the read frame number FC and the target frame number FT do not match, the processor executes step S2.
3 or step S3', where a command is sent to the tracking servo mechanism 14 to jump one track toward the outer circumference when FC<FT, and jump two tracks toward the inner circumference when FC>FT, and then proceed to step S1 again.

When it is determined in step S2 that the read frame number and the target frame number match, the processor moves to step S4 and determines whether it is a still image and the first frame based on the read still image identification code. Determine.

If it is determined in step S4 that the image is a still image and that the frame is the first frame, the processor executes step S5.
After the disc code is read twice and two frames are reproduced, the process moves to step S6, and it is determined whether or not there is an end command. If there is no end command, the process moves to step S8, and after sending out a command to jump to the inner circumference of two tracks, the process moves to step S5, and thereafter, step S6. The still image is reproduced by repeating S8.

If the frame is a still image and is not the first frame in step S4, and if there is an end command in step S6, the process moves to step S71;
Resumes execution of the routine that was being executed immediately before transitioning to step 1.

Through the above operations, the desired still image recording position is searched using the frame number code in the same way as the video recording position is searched, and the jump operation is activated using the still image identification code added to this frame number code. The desired still image is reproduced.

Note that in the above embodiment, a still image identification code is added to both of the two frames forming a still image.
Even if the still image identification code is added only to the first frame, the still image reproduction operation can be performed according to the flowchart shown in FIG. In addition, if the video signals of the four fields forming a still image are recorded from the position where the frame number of the first frame is an odd number, the still image can be played back by determining whether the frame numbers are odd or even. Since the start timing of the jump operation can be obtained, it is not necessary to add the first/second frame identification code.

The above describes the case where signals are recorded on a disk in constant rotational speed mode (CAV) and still images are played back by repeating track jump operations, but the MUSE decoder has four fields worth of memory for sample composition processing. By repeatedly reproducing the contents of this memory, still images can be reproduced even in constant linear velocity (CLV) mode.

In this case, step S8 in FIG. 5 may be used as the above-mentioned repeat reproduction operation, and step S6 and step S8 may be repeated.

Effects of the Invention As detailed above, the still image recording method according to the present invention has a 2n
A disk code consisting of a frame number corresponding to the recording position and a still image identification code is added to every two fields of the video signal that forms a still image for each field, so a single code can be used for searching and still image playback. You will be able to perform the following jumps. Therefore, the digital data multiplexing area during the vertical blanking period is not narrowed, and there is no need to switch to a search using a still image code in the search, making it easier to control the still image reproduction operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the operation of the device shown in FIG. 1, and FIG. 3 is a video disc on which signals are recorded by the device shown in FIG. 1. FIG. 4 is a block diagram showing a reproducing apparatus for reproducing still images recorded according to the present invention, and FIG. 5 is a diagram showing the arrangement of tracks.
5 is a flowchart showing the operation of the apparatus of FIG. 4.

Claims (3)

[Claims] (1) A still image recording method in which a video signal forming a still image is recorded on a recording disk for each 2n (n is a natural number) field, in which a frame number corresponding to the recording position is recorded for every 2 fields of the video signal. A still image recording method characterized by adding a still image identification code. (2) The still image identification code includes a code indicating that the video signal of the frame forms a still image, and a frame identification code indicating which frame among n frames of the video signal. A still image recording method according to claim 1, characterized in that the method comprises: (3) The still image identification code is a code indicating that the video signal of the frame forms a still image, and the frame number of the first frame among n frames of the video signal is determined in advance. 2. The still image recording method according to claim 1, wherein the video signal of the 2n fields is recorded from a position where one of the 2n fields is a predetermined odd number or even number.