JPH01198142A - Picture packet transmission equipment - Google Patents

Abstract

PURPOSE:To efficiently transmit a packet by outputting transmitted and encoded data to a packet transmission control part at an information speed corresponding to the produced quantity of data between frames. CONSTITUTION:An information speed control part 3b outputs a fixed threshold level decided based on a set speed set from the outside to a video CODEC part 1 and simultaneously outputs the information speed being suitable for the inputted generated quantity of the information, that means, a high speed when the generated quantity of the information is much and a low speed when it is small, to a CODEC, interface block 3a. Thus, the packet transmission control part 2 can construct the packet data of a packet length corresponding to the generated quantity of the information. As the data is always sent to the control part 2 at the information speed corresponding to the generated quantity of the information in this way, unnecessary data is not made be packet.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image packet transmission device, particularly an image packet transmission device that compresses and compresses image information.
The present invention relates to an improvement of an image packet transmission device that packetizes and transmits initialized data.

[Prior Art] Image information, especially video information, has a huge amount of information and requires high-speed transmission. To reduce transmission costs, read image information must be compressed and encoded. transmitted. As a compression/encoding method, an inter-frame differential encoding method has been put into practical use, in which initial screen information is encoded and transmitted, and thereafter, a difference value from the screen information of the previous frame is encoded and transmitted.

Hereinafter, a conventional bucket transmission device will be explained based on the drawings.

FIG. 3 shows a block on the transmitting side of a conventional image packet transmitting device.

In the figure, (1) is a video codec unit that compresses and encodes image information using an interframe difference method and generates compressed and encoded data;
)teeth,? 11 encoding (1a) and a threshold control unit that determines a threshold value necessary for information compression of the next frame based on information generation of compressed/encoded data generated in the encoding unit (1a). (lb).

(2) is a packet transmission control unit that packetizes the compressed/71 coded data and sends it to the line; (3) is a codec interface that interfaces between the video codec unit (1) and the packet transmission control unit (2). Department,
(4) is a trunk line.

Next, the operation will be explained. In FIG. 3, screen information is input to a video codec unit (1) frame by frame.

Then, the screen information is compared with the screen information of the previous frame in the encoding unit (1a), and difference information (interframe data) is calculated.

Further, the encoding unit (1a) encodes the interframe data based on the threshold value output from the threshold control unit (1b).
It compresses and encodes, generates compressed and encoded data, and outputs it to the codec interface unit (3).

At this time, the encoding unit (1a) outputs the amount of information generated representing the amount of the compressed and encoded interframe data (compressed and encoded data) to the threshold control unit (1b).

Then, the threshold control section (1b) causes the compressed and encoded data output from the encoding section (1a) to converge to the data log corresponding to the set speed set from the outside based on the information generation needle. Output the threshold value to the encoder (1a) (
The encoding unit (1a) generates compressed and encoded data for the next frame in consideration of this threshold value).

Here, the threshold is a value that determines the amount of compressed/encoded data between frames; if the threshold is large, the amount of compressed/encoded data is small, and if the threshold is small, the amount of compressed/encoded data is small. The amount of digitized data will increase. Therefore, the amount of information generated in compressed/encoded data is determined by the intensity of the movement of manually generated screen information (the size of the difference value between screen information between adjacent frames) and the threshold value described above. It turns out.

Next, the compressed/encoded data output from the encoder (1a) is processed by the codec interface unit (3) as transmission encoded data to which control information indicating the type of image information, etc. is added, under bucket transmission control. The information is output to section (2) at a constant information speed.

Then, the packet transmission control section (2) reads the transmission encoded data at regular intervals, assembles it into packets, and packetizes it according to a prescribed format (transmission procedure based on CCITT Remark X, 25) to send it to the relay line. (4
).

Therefore, when there is little movement on the screen and the amount of compressed/encoded data from the 7.1 encoding unit (1a) is small, the amount of data underflows, so the codec interface unit (3) only uses the communication line. By inserting idle data to be transmitted, constant information is always outputted to the packet transmission control unit (2) at a constant speed.

FIG. 4 shows an example of the data interface image between the packet transmission control section (2) and the codec interface section (3) (in the case where the set speed is 192 kl ps). In the same figure, compressed/71 coded data is always compressed and encoded at 512 times during frame pulse 1 (8ms) at the codec interface unit (3) together with the data enable signal.
interfaced to the bX3 transmit encoded data.

That is, said sending? Co-encoded data is (512x3)
b/(8xlO-3s) = 192 kbps information rate is always output to the packet transmission control unit (2).

In addition, the packet transmission control unit (2) transmits 7 at regular intervals.
Since the first coded data is read and assembled into bucket data with a fixed packet length, if the aforementioned compressed/encoded data underflows, idle data is added to the compressed/encoded data and the packet transmission control is performed. It is output to section (2).

[Problems to be Solved by the Invention] Since the conventional image packet transmission device is configured as described above, the amount of transmission data output from the transmission control section is limited to the amount when compressed/encoded data underflows. However, since idle data is transmitted, the packet length is always constant, which has the problem of poor transmission efficiency on the trunk line.

Furthermore, since the transmission efficiency is low, there is a problem that it is not particularly suitable for use in packet switching.

This invention was made to solve the problems mentioned above, and it is capable of packet transmission corresponding to the generation of compressed and encoded data, and also provides an image packet transmission device suitable for bucket exchange. The purpose is to obtain.

[Means for Solving the Problems] An image packet transmission device according to the present invention outputs packet data corresponding to compressed encoded data of interframe data, and also transmits idle data even when image data underflows. I tried not to do that.

[Operation] In the present invention, by outputting encoded data to the packet transmission control section at an information speed corresponding to the amount of interframe data generated, unnecessary data transmission is eliminated and efficient packet processing is achieved. transmission can be carried out.

[Embodiment of the Invention] Hereinafter, a preferred embodiment of the image packet transmission device according to the present invention will be described with reference to the drawings.

In addition, are the same parts as the conventional example described above? ] and the explanation will be omitted.

FIG. 1 shows a block configuration of an image packet transmission device according to this embodiment.

As shown in the figure, the video codec section (1) sends the amount of information generated to the codec interface (3).

Further, the codec interface section (3) adds additional information to the compressed encoded data output from the video codec section (1), and sends out the data after interfacing with the packet transmission control section (2). It consists of a codec interface block (3a) and an information rate control unit (3b) that determines the information rate based on the amount of information generated from the video codec unit (1).

Then, the information speed control section (3b) outputs a threshold value from the average value of the set speeds to the video codec section (1).

Next, the operation of this embodiment will be explained.

First, is the screen information input to the video codec section (1) an inter-frame difference? Compressed by No. 1 housing method? ] and outputs the compressed and encoded data to the codec interface section (3), and also outputs the amount of information generation of the compressed and encoded data associated with the inter-frame data to the information rate control section (3b). do.

The information speed control section (3b) outputs a fixed threshold determined by the set speed set from the outside to the video codec section (1), and also outputs an information speed suitable for the amount of manually generated information, that is, , a high speed is output when there is a large amount of information generated, and a low speed is output when there is little information generation, to the codec interface block (3a).

Therefore, the information speed of the output data from the codec interface block (3a) to the packet transmission control section changes every time the information generation amount changes, so the packet transmission control section (2) adjusts the packet length according to the amount of information generation. packet data can be assembled.

The packet transmission control unit (2) then sends the packet data to the relay circuit (4) according to the specified format 1-(X, 25).

That is, in order to always send data to the packet transmission control unit (2) at an information rate corresponding to information generation, unnecessary data is not packetized.

Further, FIG. 2 shows an example of an interface image between the codec interface section (3) and the packet transmission control section (2) in this embodiment.

In the same figure, the information speed is 192 kbps -> 64
An example is shown in which the speed changes from kbps to -256 kbps, but actually changes within a range of up to 384 kbps.

Note that the threshold value at this time is set to a value such that when the information speed is averaged, it becomes a value close to the setting speed set from the outside.

In the above embodiment, the information rate control section (3b) is provided in the codec interface section (3), but it can also be provided in the packet transmission control section (2) and controlled by S/W. The circuit can be simplified.

[Effects of the Invention] As described in 1-1 above, according to the image bucket transmission device according to the present invention, compression and
It is possible to perform bucketing corresponding to No. 71 data transmission, improve the transmission efficiency of the relay line, and perform image packet transmission with high efficiency suitable for packet exchange.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the transmitting side of a preferred embodiment of the image bucket transmission device according to the present invention, and FIG. 2 is an exemplary diagram of an interface image of the packet transmission control section and codec interface section according to the embodiment of FIG. FIG. 3 is a block diagram showing the transmitting side of a conventional painter packet transmission device, and FIG. 4 is an example diagram of an interface between a conventional packet transmission control section and a codec interface section. In the figure, (1) is a video codec section, (1a) is an encoding section, (1b) is a threshold control section, (3) is a codec interface section, (3a) is a codec interface block, and (3b) is an information The main part is the control section, (2
) is a packet transmission control unit, and (4) is a relay line. Note that in the figures, the same reference numerals indicate the same or equivalent parts. Agent: Patent attorney Masuo Oiwa (and 2 others) Procedural amendment (voluntary)

Claims (2)

[Claims] (1) a video codec section including an encoding section that reads transmission image information frame by frame and compresses and encodes the screen information by applying an interframe differential encoding method; and the video codec section that is output from the video codec section. a codec interface section that outputs transmission encoded data, which is the compressed and encoded screen information to which additional information such as the type of image information is added, to the packet transmission control section at a predetermined information rate interfaced with the packet transmission control section; , a packet transmission control unit that reads the transmission encoded data output from the codec interface unit at predetermined time intervals, packetizes it to generate packet data, and controls the transmission and reception of the packet data. , the codec interface unit, for each frame,
Reads the amount of information generated from compressed and encoded screen information,
an information speed control section that controls the information speed to be fast when the amount of information generation is large and to slow the information speed when the amount of information generation is small according to the amount of information generation, and transmit encoded data at the information speed controlled by the information speed control section. a codec interface unit that outputs the information to the packet transmission control unit, and transmits packet data having a packet length corresponding to the amount of information generated, and performs efficient transmission suitable for a packet switching method. image packet transmission device. (2) The image packet transmission device according to claim 1, wherein a threshold value for determining a compression rate of screen information is controlled by the information rate control section.