JPH08289288A - Moving image communication system - Google Patents

Abstract

PURPOSE: To realize the moving image communication system which does not depend on the capacity of a decoding device as the system requesting a new encoding processing and the resumption of a transmission to the encoding device at a point of time when a decoding processing is completed in the decoding device. CONSTITUTION: An image encoding device 01 in which a moving image signal 100 is inputted is provided with an encoding circuit 103 which is controlled by a control circuit receiving the start of an encoding and the instruction of the stoppage received via a transmission line and executing an encoding processing and executes an encoding processing only when the instruction of the start of the encoding is received. A moving image encoding device 02 receives moving image encoding data, executes a decoding processing and outputs a reproduced moving image. During the decoding processing, the instruction of the stoppage of the encoding is transmitted via the transmission line. When the decoding processing of a new encoding image is possible to be executed after the decoding processing is completed, the instruction of the start of the encoding is transmitted and new encoding data is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture communication system used in a television conference system or the like for coding moving picture signals and transmitting / receiving them through a communication network.

[0002]

2. Description of the Related Art Generally, an image coding apparatus used in a television conference system or the like compresses a moving image signal input at 30 frames per second into an amount of information that can be transmitted through a transmission line of a fixed rate and transmits it to a communication network. To do.

As a compression method, for example, ITU-T Recommendation H.264 is recommended. There are motion compensation interframe coding, DCT conversion coding, variable length coding, and the like adopted in H.261, and excludes space-time redundancy. Furthermore, when the compression rate is insufficient and transmission at a fixed rate is impossible, a method of thinning out input image frames is used.

The image decoding apparatus receives and faithfully reproduces compressed moving image information transmitted through a fixed rate transmission line. For example, from the encoding device 30
A frame-encoded compressed image must be faithfully decoded at 30 frames per second.

Conventionally, ITU-T Recommendation H.264 has been adopted. In the communication procedure defined by 242, when communicating with an image decoding device having a low processing capability, the encoding may be executed according to a certain decoding capability designated by the image decoding device. It is set. For example, if the image decoding device declares a decoding capability of 15 frames per second, then the image coding device is an arrangement to perform a coding of at most 15 frames per second.

[0006]

In the above-described conventional moving picture communication system, the image coding apparatus needs to perform coding within the range of the decoding capability first declared by the image decoding apparatus. is there. If the decryption process is assumed by software processing of a personal computer, etc., the interrupt process such as file transfer is dynamically entered in addition to the decryption process. There is a problem that it is not possible to respond immediately to fluctuations in. In other words, if the load exceeds the capacity declared at the beginning, it becomes impossible to decrypt, and conversely, if the load becomes less than the ability, there is a problem that idle time occurs in the decryption device and waste occurs. is there.

The present invention depends on the processing capacity of the decoding apparatus by a method of requesting the coding apparatus to restart new coding processing and transmission when the decoding processing is completed in the decoding apparatus. Provide a moving image communication method.

[0008]

The moving picture communication system of the present invention provides an instruction to control the start and stop of encoding in order to solve the above problems when the load of the image decoding apparatus changes. When receiving the encoding start instruction, start the encoding process of the encoding circuit, when receiving the encoding stop instruction, the control circuit for stopping the encoding process, and when the decoding is started, It has a decoding circuit which transmits a coding stop instruction and transmits a coding start instruction when the decoding processing of new moving image coded data can be executed.

Also, when the coding instruction signal received from the decoding apparatus by the coding apparatus is "1", the coding execution is instructed to output the coded image data, and when it is "0", the coding is carried out. May be provided and the dummy data of "1" may be output as image coded data.

[0010]

In the moving picture communication system configured as described above, an instruction for controlling the start and stop of encoding is received,
When the encoding start instruction is received, the encoding circuit starts the encoding process, and when the encoding stop instruction is received, the control circuit that stops the encoding process, and when the decoding is started, the encoding stop is performed. When the decoding processing of the new moving image coded data can be executed by transmitting the instruction, by sending the coding start instruction, the decoding apparatus decodes the image coded data of one frame. When the encoding process is completed, the encoding device is requested to restart the new encoding process and transmission, so that the processing capability of the decoding device can be maintained even when the device communicates with the decoding device having low processing capability. Work independent.

[0011]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment for realizing the present invention.

In FIG. 1, the moving picture coding apparatus 01 is
The moving image signal 100 to be input is encoded with high efficiency and transmitted as image encoded data 102. Video decoding device 02
Receives the encoded image data 102, performs decoding processing, and outputs the reproduced moving image 109.

In the moving picture coding apparatus 01, the coding circuit 03 performs a high-efficiency coding process on the input moving picture signal 100 of one frame, which will be described in detail later, and adds a header indicating the beginning of the image frame. The encoded data 101 is output.

The line interface circuit 04 transmits the input image coded data 101 to the transmission line.

The line interface circuit 04 receives the coding instruction signal 107 transmitted from the moving picture decoding apparatus 02, and outputs it to the coding circuit 03 as 108.

When the encoding circuit 03 receives the encoding instruction signal 108 of "0", after executing the encoding processing of one frame, the encoding processing of the next and subsequent frames is stopped and "1" without a header is executed. The dummy data of is output as the image coded data 101.

The encoding instruction signal 108 received is "1".
In the case of, the execution of the encoding is instructed, and in the case of "0", the stop of the encoding is instructed.

On the other hand, when the encoding instruction signal 108 of "1" is received, the encoding is started from the head of the image frame of the moving image signal 100 and the encoded image data 101 is output.

In the moving picture decoding apparatus 02, the decoding circuit 06 receives from the moving picture coding apparatus 01 through the line interface 05, one frame of the coded image data 104, and starts the image frame. When the header indicating the is detected, the decoding processing described in detail later is performed, and the reproduced moving image 109 is output. Further, the decoding circuit 06 outputs a coding instruction signal 105 for instructing the start or stop of the coding to the line interface circuit 05. The line interface circuit 05 transmits the input coding instruction signal 105 to the transmission line as 106.

Next, the operation of the encoding circuit 03 will be described in detail with reference to FIG. The encoding circuit 03 uses the encoding instruction signal 1
The following operation is executed according to the analysis result of 08.

(1) When the encoding instruction signal 108 of "1" is received: The encoding process is started from the beginning of the moving image signal 100.

The selection circuit 15 outputs the encoded data 209 as the image encoded data 101.

(2) When the encoding instruction signal 108 of "0" is received: After the encoding process of 1 frame is executed, the encoding process is stopped.

The selection circuit 15 outputs the dummy data 210 of “1” as the image coded data 101.

The buffer memory 07 newly inputs the moving image signal 100 when the encoding process is completed.

The motion detection circuit 08 has a buffer memory 07.
From the moving image signal 100 input to
To detect. Prediction error signal 200 with temporal redundancy removed
Is a motion compensation circuit 1 based on the detected motion vector 201.
4 is obtained by subtracting the motion-compensated previous frame local decoding image 202 from FIG.

The DCT conversion circuit 09 performs DCT conversion on the input prediction error signal 200.

The quantizing circuit 10 carries out an operation of dropping the wide area component of the output signal 205 of the input DCT converting circuit 09, and removes the spatial redundant component without visually deteriorating.

The variable length coding circuit 11 is a quantization circuit 10.
The output signal 206 of is input and the amount of information is compressed.

The variable-length coding circuit 11 also adds a header indicating the beginning of the image frame to the coded data 209.
Is output.

When the selection circuit 15 receives the encoding instruction signal 108 of "1", it outputs the encoded data 209 as the image encoded data 101. When the coding instruction signal 108 of "0" is received, the dummy data 2 of "1"
10 is output as image encoded data 101.

The local decoded image 204 is obtained by adding the inverse DCT transform signal 208 and the output signal 203 of the motion compensation circuit 14.

Next, the operation of the decoding circuit 06 will be described in detail with reference to FIG.

The decoding circuit 06 is used for the image coded data 10
4 is received and stored in the buffer memory 16. The header detection circuit 17 searches the stored image encoded data 104 for a header indicating the beginning of a moving image frame, and outputs a "0" encoding instruction signal 105 when a header is detected. Also, after the decoding process for one frame is completed,
The coding instruction signal 105 of "1" is output and the decoding process is stopped.

The reproduced moving image 109 is the inverse DCT circuit signal 3
It is obtained by adding 04 and the prediction error signal 306.

As described above, in the moving picture decoding apparatus 02, when the decoding processing of the image coded data 104 of one frame is completed,
The intended purpose can be achieved by a method that requires new encoding processing and restart of transmission.

[0037]

As described above, the moving picture communication system according to the present invention is capable of communicating with a decryption device having a low processing capacity and limiting the processing time allocated to the decryption process. In the above, according to the request of the decoding device, there is an effect that moving image communication that does not depend on the processing capability of the decoding device is possible.

[Brief description of drawings]

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

FIG. 2 is a block diagram for explaining an encoding circuit of the present invention.

FIG. 3 is a block diagram for explaining a decoding circuit of the present invention.

[Explanation of symbols]

 01 Moving picture coding device 02 Moving picture decoding device 03 Encoding circuit 04 Line interface circuit 05 Line interface circuit 06 Decoding circuit 07 Buffer memory 08 Motion detection circuit 09 DCT conversion circuit 10 Quantization circuit 11 Variable length Encoding circuit 12 Inverse quantization circuit 13 Inverse DCT circuit 14 Motion compensation circuit 15 Selection circuit 16 Buffer memory 17 Header detection circuit 18 Variable length decoding circuit 19 Inverse quantization circuit 20 Inverse DCT circuit 21 Motion compensation circuit 100 Motion picture input Signals 101 to 104 Image coded data 105 to 108 Coding instruction signal 109 Reproduction moving image 200 Prediction error signal 201 Motion vector 202 Local decoded image 203 Output signal 204 Local decoded image 205, 206 Output signal 208 Inverse DCT conversion signal 209 encoded data 210 da Mie data 304 Inverse DCT circuit signal 306 Prediction error signal

Claims (2)

[Claims] 1. An encoding is applied to an input moving image signal,
A coding circuit for compressing information, a line interface circuit for transmitting moving picture coded data from the coding circuit through a transmission line, and a moving picture coding for receiving the moving picture coded data In a moving picture communication system composed of a decoding circuit for decoding data and reproducing a moving picture signal, in the case where an instruction for controlling the start and stop of encoding is received and the encoding start instruction is received, the encoding circuit When the encoding process is started and the encoding stop instruction is received, the control circuit that stops the encoding process, and when the decoding is started, the encoding stop instruction is transmitted, and new moving image encoded data is transmitted. A moving picture communication system characterized by having a decoding circuit for transmitting a coding start instruction when the decoding process of is executable. 2. The encoding device instructs the execution of encoding when the encoding instruction signal received from the decoding device is "1" and outputs the image encoded data, and when it is "0", the encoding is performed. 2. The moving image communication system according to claim 1, further comprising means for stopping and outputting dummy data of "1" as image encoded data.