JP2723024B2 - Compressed image data 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 an in-frame compressed data reproducing apparatus for outputting a smooth moving image during special reproduction.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional intra-frame compressed image data reproducing apparatus.

A conventional intra-frame compressed image data reproducing apparatus includes a reproducing apparatus 11 for reproducing intra-frame compressed compressed image data 1 and a decoder 13 for decoding intra-frame compressed compressed image data 1 and returning the same to image data 2. And a playback device control unit 15 for controlling the reading of the playback device 11. To decode the compressed image data 1, it is necessary to read the compressed image data 1 from the playback device 11 in frame units.

[0004]

In the conventional in-frame compressed image data, in the case of fast-forward playback of compressed image data compressed in a frame by a playback device, for example, in double-speed fast-forward playback, the playback device control unit 15 sends a lead frame. The control signal 3 is sent to the reproducing apparatus 11 to read out the in-frame compressed image data 1 of the frame corresponding to the double speed, for example, the even number frame.

[0005] The read in-frame compressed image data 1
Are decoded by the decoder 13 and returned to the original image data to be output as output image data 5.

Here, the frames of the compressed image data 1 read from the reproducing apparatus 11 are frame units such as a second frame, a fourth frame, a sixth frame, an eighth frame, and so on.

At this time, the field numbers of the data output to the output image data 5 are the first field of the second frame, the second field of the second frame, the first field of the fourth frame, the second field of the fourth frame, Sixth
The first field of the frame, the second field of the sixth frame, the first field of the eighth frame, the second field of the eighth frame, and so on.

[0008] In the image reproduced in this manner, the images between frames are not temporally continuous, whereas the images between fields in the frame are temporally continuous. Feel

The same applies to fast-forward playback other than double-speed playback.

During slow playback, the playback device control unit 15
, A read frame control signal 3 indicating slow reproduction is sent to the reproducing apparatus 11, and the compressed image data 1 of each frame is repeatedly read out a predetermined number of times.

The read compressed image data 1 in the frame
Is restored by the decoder 13, is returned to the original image data, and is output as output image data 5.

For example, when performing slow reproduction at 1/2 speed, the compressed data of each frame is read twice, so that
The frames of the compressed image data 1 to be read are the first frame, the first frame, the second frame, the second frame, and the third frame.
The frame is repeated every two frames, such as a frame, a third frame, and so on.

At this time, the field numbers of the data output to the output image data 5 are the first field of the first frame, the second field of the first frame, the first field of the first frame, the second field of the first frame, Second
A first field of a frame, a second field of a second frame, a first field of a second frame, a second field of a second frame, and so on.

In an image reproduced in this manner, even in the same frame, since it returns to the previous field temporally once, the motion becomes unnatural and becomes unsightly.

The same can be said for slow reproduction other than 1/2 speed.

As described above, in the conventional intra-frame compressed image reproducing apparatus, the output is unsightly because the temporal positional relationship of the output image is not constant at the time of special reproduction such as fast forward reproduction or slow reproduction because the control is performed on a frame basis. There was a problem that it would become an image.

An object of the present invention is to provide an in-frame compressed image data reproducing apparatus capable of reproducing a smooth output image even during special reproduction such as fast-forward reproduction or slow reproduction.

[0018]

According to the present invention, there is provided an intra-frame compressed image data reproducing apparatus for reproducing intra-frame compressed image data.
A reproducing apparatus for reading out the intra-frame compressed image data from the recording medium on a frame basis, a decoder for decoding the intra-frame compressed image data and returning the decoded frame image data to an image signal; a memory temporarily storing for each frame, the desired read control and the reproducing apparatus in accordance with the reproduction speed, includes a system control unit for the read control of the memory, the system control unit at the time of fast forward reproduction
Depending on the desired playback speed, the playback device outputs
Control to read compressed data of the
Only the data of the first field in each frame from the memory
Or read only the data in the second field
Control function as described above.

Further, the system control unit controls the compressed data of each frame to be repeatedly read a plurality of times from the reproducing device at the time of slow reproduction in accordance with a desired reproduction speed, and performs a desired slow reproduction from the memory. According to the speed, control is performed such that only the data of the first field is read in the first half of the period during which the same frame is read from the reproducing apparatus, and only the data of the second field is read in the second half.

[0020]

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an in-frame compressed image reproducing apparatus according to the present invention.

In this embodiment, an explanation will be given using an optical disk reproducing apparatus as an example of the reproducing apparatus 11.

An example of the case of performing the fast forward reproduction at the even double speed of the double speed will be described below.

In FIG. 1, for example, when performing double-speed fast-forward playback, the system control 12 sends a read frame control signal 3 indicating double-speed fast-forward playback to the optical disk playback device 11.

On the other hand, when receiving the lead frame control signal 3, the optical disk reproducing apparatus 11 converts the in-frame compressed image data 1 recorded on the optical disk into the second, fourth, sixth, eighth,.
And reads out the intra-frame compressed image data 1 in frame units.

When the in-frame compressed image data 1 of the second frame read out frame by frame is input to the decoder 13, the decoder 13 uses the decompression method corresponding to the compression method of the recorded data to generate the frame of the second frame. The internal compressed image data 1 is decoded, and the original image data 2 of the second frame is restored.

The reconstructed image data 2 of the second frame is written into the memory 14 in frame units, and is read out under the control of the system control unit 12.

At this time, the system control 12 sends to the memory 14 a reproduction field control signal 4 meaning fast forward reproduction at double speed and reading data in the first field.

The memory 14 reads and outputs data in the order of the first field 1 and the second field during one frame during normal reproduction, but receives the reproduction field control signal 4 and outputs the first field 1 during one frame. Is repeatedly read twice and output as image data 5.

The in-frame compressed image data 1 sequentially read from the optical disk reproducing device 11 in frame units will be described below.
To output image data 5.

As shown in FIG. 4, the field numbers of the output image data 5 obtained as a result of the fast forward reproduction are the first field of the second frame, the first field of the second frame, and the first field of the fourth frame. Field, the first field of the fourth frame, the first field of the sixth frame,
The first field of the sixth frame,...

In the double speed reproduction of the present embodiment, the reproducing apparatus 11 reads data from even frames, but may read data from odd frames.

Although only the first field data is read from the memory 14, only the second field data may be read.

As described above, by controlling the output image so that the image data is output twice in one frame at a fixed period during the fast forward reproduction, the image data is output from the same field group of the output image data. Since the time interval is kept constant, it is possible to perform fast forward reproduction with a smooth reproduced image.

Next, the case where slow reproduction is performed will be described.

An example in which slow reproduction is performed at 1/2 speed will be described below.

In FIG. 1, when performing slow reproduction at 1/2 speed, for example, the system control 12
A lead frame control signal 3 indicating slow reproduction at / 2 × speed is sent to the optical disk reproducing device 11.

Upon receiving the lead frame control signal 3, the optical disk reproducing apparatus 11 converts the in-frame compressed image data 1 recorded on the optical disk into a first frame, a first frame, a second frame, a second frame, and a third frame. , The third frame, etc., the intra-frame compressed image data 1 of each frame is repeatedly read twice in frame units.

When the in-frame compressed image data 1 of the first frame read out for the first of the two repetitive readings is input to the decoder 13, the decoder 13 performs a decompression method corresponding to the compression method of the recorded data. First using
The in-frame compressed image data 1 of the frame is decoded, and the original first frame image data 2 is restored.

The reconstructed image data 2 of the first frame is written into the memory 14 in frame units, and is read out under the control of the system control 12.

The system control 12 sends to the memory 14 a reproduction field control signal 4 meaning slow reproduction and reading the data of the first field.

The memory 14 receives the reproduction field control signal 4 and stores the first field in two frames in one frame.
It is read out repeatedly and output as image data 5.

Next, the compressed image data 1 of the first frame read out the second time out of the two times of repeated reading out
Is input to the decoder 13, the decoder 13 decodes the in-frame compressed image data 1 of the first frame using an expansion method corresponding to the compression method as in the first reading, and outputs the image data 2 of the first frame. To restore.

The restored first frame image data 2 is written to the memory 14.

The system control 12 sends to the memory 14 a reproduction field control signal 4 meaning slow reproduction and reading data of the second field.

In response to the reproduction field control signal 4, the memory 14 repeatedly reads out the data of the second field twice in one frame and outputs it as image data 5.

The in-frame compressed image data 1 sequentially read from the optical disk reproducing device 11 in frame units will be described below.
To output image data 5.

The field numbers of the output image data 5 resulting from the slow reproduction in this manner are, as shown in FIG. 5, the first field of the first frame, the first field of the first frame, and the second field of the first frame. A field, a second field of the first frame, a first field of the second frame,
The first field of the second frame, the second field of the second frame, the second field of the second frame, and so on.

As described above, the time interval of the same field group of the output image data is kept constant by controlling the image data to be output twice in the same field in one frame during the slow reproduction. Because of the dripping, it is possible to perform smooth slow reproduction of the reproduced image.

In this embodiment, an optical disk reproducing device is used as the reproducing device 11. However, any reproducing device may be used as long as it can reproduce data on a frame basis, such as a VTR or a magnetic disk.

[0052]

As described above, the compressed image data reproducing apparatus according to the present invention controls the output image data for each field in spite of reproducing the compressed data in units of frames in order to decode the data. At any playback speed, the time interval of the same field group of the output image data can be kept constant.

Therefore, it is possible to reproduce an image having a smooth motion during fast forward reproduction or slow reproduction.

[Brief description of the drawings]

FIG. 1 is a block diagram of an in-frame compressed image data reproducing apparatus according to the present invention.

FIG. 2 is a block diagram of a conventional in-frame compressed image data reproducing apparatus.

FIG. 3 is an example of a field number of output image data during normal reproduction according to the present invention.

FIG. 4 is an example of a field number of output image data at the time of fast-forward reproduction according to the present invention.

FIG. 5 shows an example of a field number of output image data at the time of slow reproduction according to the present invention.

FIG. 6 shows an example of a field number of output image data at the time of conventional fast-forward reproduction.

FIG. 7 shows a field number example of output image data at the time of conventional slow reproduction.

[Explanation of symbols]

 1 compressed image data within a frame 2 decompressed image data 3 lead frame control signal 4 playback field control signal 5 output image data 11 playback device 12 system control unit 13 decoder 14 memory 15 playback device control unit

Claims (2)

(57) [Claims] An image data reproducing apparatus for reproducing intra-frame compressed image data, comprising: a reproducing device for reading out the intra-frame compressed image data from a recording medium in frame units;
A decoder for decoding the compressed image data in the frame and returning the decoded image data to an image signal; a memory for temporarily storing the decoded frame image data for each frame; reading control of the playback device according to a desired playback speed; A system control unit for controlling readout , wherein the system control unit performs desired playback during fast forward playback.
A frame of a fixed cycle from the playback device according to the playback speed
Control to read compressed data of
Only the data of the first field in each frame from
Or read only the data in the second field
A compressed image data reproducing device having a control function . 2. The system control section controls, during slow playback, to repeatedly read compressed data of each frame a plurality of times from the playback device in accordance with a desired playback speed, and performs desired slow playback from the memory. 2. The compressed image data reproduction according to claim 1, wherein control is performed such that only the data of the first field is read in the first half of the period during which the same frame is read from the reproduction device in accordance with the speed, and only the data of the second field is read in the second half. apparatus.