JP3308523B2 - Multi-screen playback device for compressed images - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a device that reproduces a moving image by recording the moving image in a compressed manner on a recording medium such as a CD-ROM, and particularly relates to a multi-screen of a compressed image that enables high-quality reproduction. It relates to a playback device.

[0002]

[Prior art]

As means for high-quality image reproduction of a moving image compressed image recording and reproduction system, an original screen is spatially divided and recorded on a plurality of recording media, and reproduction is performed, particularly, the divided images of the recording medium are combined and displayed. Multi-screen playback technology has not been developed yet.

[0003]

[Problems to be solved by the invention]

In order to realize the above-described multi-screen recording / playback system, each system included in the image playback unit for playing back a divided image from each recording medium has the same configuration, and it is necessary to perform decoding completely in synchronization with each other. It is.

[0004] To this end, each system simultaneously reads compressed image data from a recording medium and accumulates the data in a temporary buffer memory.
This data is read and decoded for each frame. A slight phase shift of each system can be corrected by accumulating it in a buffer memory. However, for example, if there is an error in reading from the recording medium, the driver that reads the image data from the recording medium performs this correction operation, so that a significant delay occurs and correction cannot be performed.

[0005] Compressed image data is recorded on a recording medium for each frame. However, since there is no means for identifying a frame, when reproducing the recording medium, if the above-described phase shift is large, the compressed image data is mutually recorded. In some cases, image data of different frames is reproduced.

Japanese Patent Application Laid-Open No. 61-265983, “Multi-Video Display Method”, discloses a timing signal generated by the first recording medium reproducing apparatus to control the reproduction timing of each of the first and second recording medium reproducing apparatuses. A method is disclosed in which the display timings of the respective portions when displaying each portion of a single video on each of a plurality of video display devices are made to match each other by making them match. However, in this method, the first recording medium reproducing device generates a timing signal at a predetermined time, and the second recording medium reproducing device reproduces a predetermined position in response to the timing signal. The role of the personal computer that performs the frame synchronization control by focusing on the frame address is merely assigned to the first recording medium reproducing device. In addition, if the first recording medium reproducing apparatus does not generate a timing signal for some reason or the second recording medium reproducing apparatus fails to receive the timing signal, the second recording medium reproducing apparatus Will be left in a reproduction interrupted state while waiting for the arrival of a timing signal, so that the second recording medium reproducing apparatus cannot prompt the first recording medium reproducing apparatus to generate a timing signal, so that it is stuck for a long time. There was a problem that the state continued. The conventional method in which a personal computer controls frame synchronization is also a second method.
Lacks the flexibility to cope with the increase or decrease in the number of recording medium playback devices, the modification of the operation program is required when the number of storage medium playback devices to be controlled changes, and lacks general-purpose support capabilities. It had problems. Further, regardless of whether the frame synchronization control is performed by the first recording medium reproducing apparatus or by the personal computer, the non-compressed image data is recorded on the recording medium. As described above, there is no need to perform frame synchronization control in accordance with different decoding processes depending on the degree of compression, and a simple control system can cope with the small variation in the playback frame period between the recording medium playback devices. On the contrary, there is a problem that the possibility of diverting the compressed image data to the frame synchronous reproduction technology is narrowed.

Japanese Patent Application Laid-Open No. 63-274275 discloses a system in which a parameter for determining an image encoding condition is recorded together with an original image signal. Although this system handles compressed image data, it has a problem that it is necessary to devise various measures in a reproducing apparatus in order to perform frame synchronous reproduction of a plurality of recording media with frame numbers read from the recording media. Was something.

In view of the above circumstances, an object of the present invention is to provide a multi-screen playback apparatus for a compressed image which can correct the reading of a compression-encoded image division recording medium even if there is a synchronization error. It is in.

[0009]

[Means for Solving the Problems]

A multi-image playback apparatus for compressed images according to the present invention has solved the above-mentioned problem, and a frame image is spatially divided into a plurality of divided images, and each divided image is compression-encoded and divided. Each of the divided compressed image data is read from a plurality of recording media in which a frame synchronization time code is added to each of the divided compressed image data and stored in a dedicated buffer, and is included in each of the compressed image data. Based on the time code for frame synchronization, read the compressed image data of each buffer while synchronizing the frame, decode the read compressed image data,
A plurality of divided images are combined and displayed on one or a plurality of monitors.

[0010] The multi-image reproduction apparatus for compressed images of the present invention may further comprise a plurality of buffer memories for individually storing the compressed image data read from the recording medium, and a method for storing the compressed image data stored in each of the buffer memories. A plurality of decoding circuits for reading and decoding each of the decoding circuits, a plurality of frame memories for respectively writing the decoding outputs of the respective decoding circuits, and one or a plurality of display units for combining and displaying a plurality of divided images from the plurality of frame memories; And a timing correction circuit that controls reading of compressed image data from each buffer memory while synchronizing frames based on a frame synchronization time code included in the compressed image data to be read from each buffer memory. It is characterized by including.

The fact that each divided compressed image of the same frame of the original image is stored in the buffer memory with a time lag in each system of the image reproducing apparatus means that the time contained in the image data from the buffer memory It is detected by the timing correction circuit based on the code. Among the divided compressed image data, the synchronous correction can be performed on the divided image data having the earliest phase by suspending the decoding until the other divided image data has the same time code.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below with reference to the drawings. This example shows the simplest case where the original image is divided into two as shown in FIG. 3, but the number of divisions can be arbitrarily set. Each divided image data is compressed and encoded, and CD
-Store them in the ROM 10 and 20, respectively. As shown in FIG. 2, a time code having a one-to-one correspondence with each frame is recorded in the frame data of each CD-ROM. That is, for the same frame screen, CD-ROM10,20
Have the same time code, number this time code in frame order, and use it as moving image synchronization data.

Although the details of the image recording apparatus for recording the divided image data on the CD-ROMs 10 and 20 are omitted, a time code for achieving frame synchronization is interwoven with the compressed image data of the divided image. Any device capable of recording can be used.

FIG. 1 shows the overall configuration of an image reproducing apparatus using the CD-ROMs 10 and 20 to which the above time codes are added. This device
The CD-ROM has an image reproducing unit 1 composed of a plurality of threads each having the same circuit configuration. However, in FIG. 1, the controller 101 and the timing correction circuit 102
Common to the system. Then, the display unit 2 gives the reproduced image data of each system to each monitor of the monitor group 104 by the switch 103 in a time division manner. Since the arrangement of the monitors in the monitor group 104 and the CD-ROM into which the original image is divided into two correspond to each other, the original image is displayed as one screen.

Hereinafter, the reproducing operation will be described in detail. Driver 11,21
Drives CD-ROMs 10 and 20 to read data at 1.2 Mbi
At the speed of t / s, data error detection and correction are performed. When the controller 101 sends a read start command to the CD-ROM interfaces 12, 22, the CD-ROM
The interfaces 12 and 22 read data from the drivers 11 and 21 and write the data into the buffer memories 14 and 24 under the control of the buffer memory controllers 13 and 23. Buffer memory 1
In accordance with instructions from the buffer memory controllers 13 and 23, the frames 4 and 24 cut out data for one frame from the stored data every frame period, and
5,25, audio data is audio decoding unit (not shown)
And the time code included in the frame data is 2
The signal is transferred to the timing correction circuit 102 common to the systems. The timing correction circuit 102 has a register 102A, and registers a time code sent from each system. Now, both systems are out of sync. For example, CD-RO
If the image data from M20 is delayed, the time codes registered in the register 102A do not match. At this time, the timing correction circuit 102 sends a reproduction stop signal to the buffer memory controller 13 of the system of the CD-ROM 10 that is proceeding. Upon receiving this signal, the buffer memory controller 13 stops transferring image data to the decoding circuit 15 and sends the dummy data written in the buffer memory controller 13 to the decoding circuit 15 and the audio decoding unit. At this time, the system from the CD-ROM 20 continues to operate as before, and after a lapse of time, the timing correction circuit 102 detects, for example, a match with the time code of the system of the CD-ROM 10 in the next frame. At this time, the timing correction circuit 102
The reproduction stop signal to 3 is released, and thereafter, the image data of the two systems is completely synchronized.

From the buffer memories 14 and 24, the video compression codes are sent to the decoding circuits 15 and 25, and the two are synchronized by the timing correction circuit 102, and stored in the frame memories 16 and 26 by the frame memory controllers 17 and 26. Written and read under 27.

The read video signal data is transmitted to the NTSC encoder 1
It is converted to an NTSC signal by 8,28. Switch 103 is 2
The outputs of the NTSC encoders 18 and 28 of the system are time-divisionally switched and displayed on each monitor of the monitor group 104.

Although the above embodiment is a case of two divisions, when the number of divisions is further large, the reproduction stop of the earliest system is performed, and even if the next system has the same time code as the earliest system, If the time code does not match the other systems, the reproduction of the next earlier system is also stopped. When the time codes of all systems match, the stop of the system that has been stopped until now is released.

In the above-described embodiment, the case where each system is displayed on a separate monitor arranged close to each other to form one screen is taken as an example. However, image data of each system is written in one frame memory. In addition, it goes without saying that the present invention is also applied to a method of performing composite display on one monitor. In addition,
Here, composing and displaying one screen on a plurality of separate monitors is referred to as proximity display, and composing and displaying one screen on a single monitor is referred to as composite display to distinguish them. . However, it goes without saying that both the proximity display and the composite display are concepts that can be included in the composite display in a broad sense.

[0020]

【The invention's effect】

As described above, according to the present invention, a frame image is divided into a plurality of spatially divided images, each of which is compression-encoded, and a time code for frame synchronization is added to each of the divided compressed image data. While recording on a recording medium, reading each of the divided compressed image data from the recording medium, storing the read compressed image data in a dedicated buffer, and establishing frame synchronization based on a frame synchronization time code included in each compressed image data. While reading the compressed image data in each buffer, decoding the read compressed image data, and displaying the images in close proximity to each other or displaying them together, the compressed image data read from the recording medium has a phase shift. In addition, each image data can be decoded in a state where the frame shift is corrected by correcting this shift, thereby synchronizing each divided image. High-quality multi-screen playback is possible, and the time code for frame synchronization is added to the data recorded on each recording medium at the time of recording on the recording medium and recorded. Unlike the method of recording the time code for synchronization, there is no brittleness peculiar to a centralized system such that the success or failure of frame synchronization control depends on the recording quality of a specific recording medium, and the compression recorded on the recording medium Even if the decoding / reproduction of the image data differs depending on the degree of compression, by comparing the frame synchronization time code read for each recording medium, it is possible to perform accurate frame synchronization control according to the decoding process. It works.

Further, according to the present invention, the timing correction circuit performs the frame synchronization based on the frame synchronization time code included in the compressed image data read from each buffer memory to the decoding circuit while synchronizing the compressed image data from each buffer memory. Since reading of data is controlled, decoding to the decoding circuit is performed while completing frame by frame. Therefore, the decoded data stored in the frame memory is completely in phase, and the synchronized high level is obtained for each divided image. This produces effects such as enabling multi-screen reproduction of image quality.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 shows a format for writing on a recording medium.

FIG. 3 is a diagram showing division of an original image.

[Explanation of symbols]

 1 ... image reproducing unit, 2 ... display unit, 10,20 ... CD-ROM, 13,23 ... buffer memory controller, 14,24 ... buffer memory, 15,25 ... decoding circuit, 101 ... Controller, 102: Timing correction circuit, 103: Switch, 104: Monitor group

(56) References JP-A-61-265983 (JP, A) JP-A-56-157180 (JP, A) JP-A-63-274275 (JP, A) Patent 2812780 (JP, B2)

Claims (2)

(57) [Claims] A frame image is spatially divided into a plurality of divided images, each divided image is compression-encoded, and a time code for frame synchronization is added to each of the divided compressed image data. Read each of the divided compressed image data from a plurality of recorded recording media,
Based on the frame synchronization time code included in each compressed image data, the compressed image data is read out from each buffer while being stored in each dedicated buffer and synchronized with the frame.
A multi-screen reproduction apparatus for a compressed image, wherein each of the read compressed image data is decoded, and a plurality of divided images are combined and displayed on one or a plurality of monitors. 2. A plurality of buffer memories for respectively storing compressed image data respectively read from the recording medium,
A plurality of decoding circuits for reading out the compressed image data stored in each of the buffer memories and decoding each of the compressed image data, a plurality of frame memories for individually writing the decoded output of each of the decoding circuits, and a plurality of And one or more display means for synthesizing and displaying the divided images, and a compressed image from each buffer memory while synchronizing the frames based on a frame synchronization time code included in the compressed image data read from each buffer memory. 2. The multi-screen reproduction apparatus for compressed images according to claim 1, further comprising a timing correction circuit for controlling data reading.