JP2962220B2 - Video signal playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal reproducing apparatus, and more particularly to a video signal reproducing apparatus for reproducing a video signal recorded on a recording medium such as a magnetic tape or a magneto-optical disk to obtain a slow-motion reproduced video signal.

[0002]

2. Description of the Related Art A video signal reproducing apparatus for reproducing a video signal already recorded on a recording medium can perform slow motion reproduction in which the motion of an image of a video signal recorded conventionally is displayed more slowly than at the time of recording. It is well known that there are devices. As a video signal reproducing apparatus, in a magnetic recording / reproducing apparatus (VTR) which records a video signal on a magnetic tape by a rotating head and reproduces the video signal, the running speed of the magnetic tape is slower during the slow motion reproduction than during the recording. Then, a slow-motion playback video signal is obtained by repeatedly playing back a certain track a specified number of times and then proceeding to the next track a specified number of times.

Further, in a disk recording / reproducing apparatus such as a magneto-optical file for recording and reproducing a video signal on a magneto-optical disk, a recording track of the disk such as a magneto-optical disk which rotates at the same number of revolutions as during recording is designated. A slow-motion playback video signal is obtained by performing head transfer control so that the playback is repeated a number of times and the process proceeds to the repetition of the next track a specified number of times.

[0004]

However, during the above-described slow motion reproduction, only odd or even fields may be reproduced depending on the speed ratio of the slow motion, and an image of the same field may be repeatedly reproduced. In such a case, if the video at the time of slow motion reproduction is interpolated from the video information of one field, the texture in the depth direction (time axis direction) is reduced. In addition, since the display device that displays the slow-motion playback video signal displays an image by interlaced scanning, the slow playback image appears to vibrate in the vertical direction of the screen (blurring occurs), and the image quality deteriorates.

[0005] The present invention has been made in view of the above points,
It is an object of the present invention to provide a video signal reproducing apparatus capable of obtaining a slow-motion reproduced image having a smooth texture and a texture in a depth direction without vertical movement.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and comprises a plurality of cascaded memories each storing video data of one field or an integer multiple thereof, and a desired slow speed. A coefficient generating means for outputting a coefficient having a value corresponding to the motion reproduction speed ratio in a predetermined sequence; and repeatedly outputting stored video data of a plurality of memories in accordance with a desired slow motion reproduction speed ratio. a memory control means for updating the stored image data in accordance with the reproduction speed ratio, double
Are provided corresponding to the number of memories, and each of the
Process at least the color signal of the read video data
And read video data from each of a plurality of memories.
Color field based on data and reference sync signal
The comb filter circuit based on the judgment result.
Field judgment to perform color signal phase adjustment
A mixer circuit for multiplying a plurality of video data read out from a plurality of comb filter circuits by coefficients from coefficient generating means and then combining them to output slow-motion playback video data And a configuration having:

[0007] Thus, the multiplication of the coefficient to be performed on image data read from said plurality of memory in a mixer circuit, it is possible to perform the optimum interpolation process to the desired slow-motion playback speed ratio and ,Kara
-In the comb filter circuit by the judgment of the field
Ru can phase alignment of the color signal.

Further, the coefficient generation means of the present invention gradually reduces the ratio of video data to be reproduced next among video data read from a plurality of memories constituting composite video data output from the mixer circuit. This is characterized in that a coefficient is generated which changes the value such that the number increases. As a result, the value of the coefficient differs for each interpolation point, and data loss in the depth direction can be compensated.

[0009]

[0010]

Next, an embodiment of the present invention will be described.

FIG. 1 is a block diagram showing an embodiment of a video signal reproducing apparatus according to the present invention. In this figure, this video signal reproducing apparatus is provided corresponding to a cascade-connected first memory 1 and a second memory 2 and read-out sides of these memories 1 and 2, respectively. A first comb filter circuit 3 and a second comb filter circuit 4; and a mixer for multiplying the output signals of these comb filter circuits 3 and 4 by a coefficient given in accordance with a slow motion reproduction speed ratio and then adding the resultant signals. A circuit 5, a color field determination circuit 6 to which a reference synchronization signal is input from the outside, and slow-motion playback speed data input via a system bus 9, based on which the memories 1 and 2 are controlled and an address signal is output. Control circuit 7
And a coefficient unit 8 for supplying a coefficient to the mixer circuit 5.

The first and second memories 1 and 2 store one field of the input slow reproduction image data.
The first and second comb filter circuits 3 and 4 are each provided with a comb filter for Y / C separation and a process (for example, phase inversion or field interpolation, etc.) for the separated color signal data in accordance with a color field. ), And a synthesizing circuit for synthesizing again the output color signal data of the processing circuit and the luminance signal data separated by the Y / C separating comb filter and outputting the result.

The mixer circuit 5 receives multipliers 51 and 52 to which the coefficients are inputted from the coefficient unit 8 and to which the output data of the comb filter circuits 3 and 4 are inputted, and to both output signals of the multipliers 51 and 52. , And an adder 53 that outputs the resultant data as output data. The coefficient circuit 8 generates a coefficient of a value that changes in a predetermined sequence stored in advance according to the slow reproduction speed ratio based on an address corresponding to the slow reproduction speed ratio input from the control circuit 7 and multiplies the coefficient. These circuits output to the devices 51 and 52, respectively, and are constituted by, for example, a read-only memory (ROM).

The color field determination circuit 6 determines a color field of input video data based on a reference synchronization signal input from the outside. In the case of an NTSC video signal, as is well known, the phase of a color signal is 90 per field.
The delay is such that the color signal data is cycled in four fields, so that for the purpose of field interpolation or the like, the input color signal data is in any of the phases of the four fields described above, that is, in the color field in one cycle in four fields. It is necessary to determine which color field it is and perform color signal processing (such as color inversion) according to the field to be output. For this purpose, a color field determination circuit 6 is provided.

Next, the operation of this embodiment will be described. For example, input video data obtained by reproducing a reproduced video signal obtained by reproducing an NTSC video signal recorded on a recording medium at an arbitrary slow-motion reproduction speed ratio in the form of a composite signal is 1 is supplied to the memory 1 and written.

The video data written in the first memory 1 is supplied to the second memory 2 and written therein.
It is supplied to the first comb filter circuit 3. The video data written in the second memory 2 is supplied to a second comb filter circuit 4. The video data stored in the first memory 1 and the second memory 2 are supplied to the color field determination circuit 6 together with the reference synchronization signal, and the respective color fields are determined.

The judgment result obtained by the color field judgment circuit 6 is supplied to the comb filter circuits 3 and 4 as a control signal. The comb filter circuits 3 and 4 separate Y / C image data of different fields input from the memories 1 and 2 by the internal Y / C separation comb filter, respectively. After the internal processing circuits perform color phase matching based on the determination result, the luminance signal data in the separated input video data and the internal synthesis circuit are again synthesized and output to the mixer circuit 5.

On the other hand, slow-motion playback speed data indicating the current slow-motion playback speed ratio is input to the control circuit 7 from a host device (not shown) via the system bus 9. The control circuit 7 identifies the current slow-motion playback speed ratio from the input data, generates a control signal in accordance with the ratio, controls the write / read operation of the memories 1 and 2, and outputs the combined ratio of each system. And supplies the generated address to the coefficient unit 8. The coefficient unit 8 generates a coefficient calculated in advance in the mixer circuit 5 by switching a coefficient calculated in advance so as to be optimal at the interpolation point with respect to the video data of the current slow motion reproduction speed ratio indicated by the input address. To the multipliers 51 and 52, respectively.

Multipliers 51 and 52 multiply the above coefficients by the video data input from the comb filter circuits 3 and 4, respectively, and apply the video data weighted by the input coefficients to the adder circuit 53 in field units. Supply.
The addition circuit 53 adds and combines the output multiplication results of the multipliers 51 and 52 and outputs the result as video data of the same field. At the time of normal reproduction, the output video data of the comb filter 3 is output as it is without being added and synthesized by the mixer circuit 5 (that is, the coefficient to the multiplier 51 at this time is “1”, The coefficient to 52 is "0").

Next, the specific operation of this embodiment at the time of slow motion reproduction will be further described. Now, the second
It is assumed that the reproduced video data A of the field in the memory 2 is stored, and the reproduced video data B of the next field is stored in the first memory 1, for example. in this case,
During a period until the reproduced video data C of the next field is input to the memory 1, the first and second memories 1 and 2 are prohibited from performing a write operation, and the first and second memories 1 and 2 are not written.
Of the stored data B and A are maintained.

The reproduced video data C of the next field
Is input to the memory 1 until the first memory 1
Is continuously read and supplied to the comb filter 3 and the color field determination circuit 6, respectively.
The data A stored in the memory 2 is read and continuously supplied to the comb filter 4 and the color field determination circuit 6, respectively, and further processed by the comb filter circuits 3 and 4 such as color phase matching. A and B continue to be supplied to multipliers 51 and 52 in mixer circuit 5, respectively. To the multipliers 51 and 52, coefficients previously calculated so as to be optimal at the interpolation point are input from the coefficient unit 8 as described above.

Here, as an example, assuming that the current slow-motion playback speed ratio is 1/5, the input video data is updated only once in five fields.
During the field, the video data B is output from the comb filter circuit 3 and the video data A is output from the comb filter circuit 4. On the other hand, the first coefficient output from the coefficient unit 8 to the multiplier 51 is “0”, “1/5”, “2 /
5 "," 3/5 "," 4/5 ", and" 1 "are switched so as to increase sequentially for each field, while the second coefficient output from the coefficient unit 8 to the multiplier 52 is switched. Is
"1", "4/5", "3/5", "2/5", "1 /
Switching is performed so as to decrease sequentially for each field at the values of "5" and "0".

As a result, the adder 53, which adds and synthesizes the output multiplication results of the multipliers 51 and 52, outputs A, (4A + B) /
5, (3A + 2B) / 5, (2A + 3B) / 5, (A +
4B) / 5 interpolation data is extracted for each field.

As shown in FIG. 2, during slow-motion playback at 1 / 5.times. Speed, four fields during which only video data A is switched to video data B only are obtained by combining both video data A and B. Since interpolation processing is performed on video data, and the ratio of the video data B is gradually increased as compared with the video data A, a slow-motion playback image with smooth motion can be obtained. Further, by changing the synthesis ratio of both video data for each interpolation point, it is possible to compensate for the lack of data in the depth direction.

Also, when performing slow motion reproduction at 2/15 × speed, it can be realized by repeatedly reproducing two fields of video data per 15 fields. For example, interpolation data generated from video data A and B is used. Seven fields are reproduced, and eight fields are reproduced using interpolation data generated from the next video data B and C.

That is, the video data B is stored in the multiplier 51,
The eight fields in which the video data A is input to the multiplier 52 are the first fields output from the coefficient unit 8 to the multiplier 51.
Are “0”, “2/15”, “4/15”, “6”
/ 15 "," 9/15 "," 11/15 "," 13/1
The values are switched so as to increase sequentially for each field by the values of "5" and "1". On the other hand, the second coefficients output from the coefficient unit 8 to the multiplier 52 are "1", "13/15", "1
1/15 "," 9/15 "," 6/15 "," 4/1
Switching is performed so as to decrease sequentially for each field at the values of "5", "2/15", and "0".

Subsequently, the video data C is stored in the memory 1, and the video data B read from the memory 1 is stored in the memory 2. Then, in the next eight fields where the video data C is input to the multiplier 51 and the video data B is input to the multiplier 52, the first coefficient output from the coefficient unit 8 to the multiplier 51 is “2 / 15 "," 4/15 "," 6 "
/ 15 "," 9/15 "," 9/15 "," 11/1
The switching is performed so as to sequentially increase by the value of “5”, “13/15”, and “1” for each field, while the second coefficient output from the coefficient unit 8 to the multiplier 52 is “13/1”.
5 "," 11/15 "," 9/15 "," 6/15 ",
Switching is performed so as to sequentially decrease by the value of “6/15”, “4/15”, “2/15”, “0” for each field. Hereinafter, the same operation as described above is repeated.

As a result, the adder 53 for adding and synthesizing the output multiplication results of the multipliers 51 and 52, as shown in FIG.
A + 2B) / 15, (11A + 4B) / 15, (9A +
6B) / 15, (6A + 9B) / 15, (4A + 11
B) / 15 and (2A + 13B) / 15 interpolation data are extracted for each field.
And C to B, then (13B + 2C) / 15, (11
B + 4C) / 15, (9B + 6C) / 15, (6B + 9
C) / 15, (6B + 9C) / 15, (4B + 11C)
/ 15, (2B + 13C) / 15 interpolation data is 1
Retrieved field by field. That is, (6B + 9
C) / 15 is output twice.

At the time of slow motion reproduction at 2/15 × speed, as can be seen from FIG. 3, six fields during switching from only video data A to only video data B, and
The seven fields during switching from only the video data B to only the video data C are video data obtained by combining the two video data A and B, or B and C, and the ratio is the ratio of the video data to be reproduced next. Is gradually increased, so that a slow-motion reproduced image having a smooth motion can be obtained. Further, by changing the synthesis ratio of both video data for each interpolation point, it is possible to compensate for the lack of data in the depth direction.

In the above description, 1/5 times speed and 2/1 speed
Although the description has been given of the 5 × slow-motion playback, it goes without saying that a similar effect can be obtained with other slow-motion playback speed ratios. Further, in the above embodiment, the interpolation data is generated from the video data of the two fields by using two memories, but the interpolation data is generated from the output video data by using three or more memories. You can also. Further, the memories 1 and 2 can be frame memories. The input video data is not limited to slow-motion-reproduced data, and a slow-motion-reproduced image can be obtained by intermittently inputting normally reproduced data.

[0031]

As described above, according to the present invention,
Multiplication of the video data read from a plurality of memories by the mixer circuit with a coefficient to be performed enables optimal interpolation processing to be performed at a desired slow-motion playback speed ratio. Images can be obtained.

Further, according to the present invention, the ratio of video data to be reproduced next among the video data read from a plurality of memories constituting the composite video data output from the mixer circuit gradually increases. By multiplying the video data by a coefficient that causes the value to change gradually, the value of the coefficient differs at each interpolation point, and data loss in the depth direction can be compensated for. It is possible to obtain a slow-motion playback image of a simple motion.

Further, according to the present invention, since the color signal is discriminated and the phase of the color signal is adjusted, it is possible to obtain a high-quality slow-motion reproduced image having no hue error.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation at the time of 1/5 slow reproduction in FIG. 1;

FIG. 3 is an explanatory diagram of an operation at the time of 2/15 slow reproduction in FIG. 1;

[Explanation of symbols]

 1, 2 memory 3, 4 comb filter circuit 5 mixer circuit 6 color field judgment circuit 7 control circuit 8 coefficient unit 9 system bus 51, 52 multiplier 53 adder

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 5/937 G11B 5/027 501 G11B 20/02 H04N 5/783 H04N 9/87

Claims (2)

(57) [Claims] 1. A cascade-connected one file each.
Field or an integral multiple of that field
And a coefficient of a value corresponding to a desired slow-motion playback speed ratio.
A coefficient generating means for outputting in a predetermined sequence;
Output repeatedly according to the slow motion playback speed ratio of
At the same time as the desired slow-motion playback speed ratio.
Memory control means for updating stored video dataA plurality of memories are provided corresponding to the plurality of memories, and the plurality of memories are provided.
Processing at least the color signal of each read video data of the memory
And a comb filter circuit Each of the read video data of the plurality of memories and a reference synchronization signal
The color field is determined based on the
Of the color signal in the comb filter circuit based on
A color field determination circuit for performing matching, The pluralityComb filter circuitMultiple read from
For the video data, the
After multiplying the numbers, they are synthesized and
Having a mixer circuit for outputting raw video data.
A video signal reproducing device characterized by the following. 2. The image processing apparatus according to claim 1, wherein the coefficient generation unit gradually increases a ratio of video data to be reproduced next among video data read from the plurality of memories constituting the composite video data output from the mixer circuit. 2. The video signal reproducing apparatus according to claim 1, wherein a coefficient that changes the value so as to increase is generated.