JPH04248786A - Rate variable type video coding transmission method and rate variable type video coding transmitter - Google Patents

Abstract

PURPOSE:To reduce information quantity sent in response to a revision of a coded parameter from a video coder at a sender side with respect to a rate variable type video coding transmission method and a rate variable type video coding transmitter able to revise share of bands to each video image when a coding rate is revised to send plural videos, images. CONSTITUTION:A coder side revises the setting of a coded parameter in the video coding transmission method coding video information and sending it in response to a prescribed coded parameter, the revised coded parameter control information is subject to packet processing and sent to a decoder side and an area displaying coded parameter control information is provided to a packet sent from the coder to the decoder and the decoder extracts the coded parameter control information set by the coder from the reception packet and decodes the data in response to the coded parameter.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a video encoding transmission method and a video encoding transmission device used in a high-speed wideband transmission system suitable for video transmission, in which a plurality of videos are transmitted by changing the encoding rate. The present invention relates to a variable rate video encoding/transmission method and a variable rate video encoding/transmission device that enable changing the bandwidth allocation for each video.

[0002] CCITT's I
There is an asynchronous transfer mode (ATM) using broadband ISDN recommended in the series, which divides information into cells (a type of packet) and transmits them. One cell is divided into a header that indicates the cell's destination and route, and an information field that contains user information. The feature of this method is that since the user terminal can transmit only significant information in a cell, the transmission path can be used more effectively by not transmitting unnecessary information.

0003

2. Description of the Related Art In conventional video transmission, quantization step width, video area, scale, and other encoding parameters are determined in advance between a video encoding device and a video decoding device. Therefore, it has not been possible to unilaterally change these encoding parameters in accordance with a request from a video encoding device on the transmitting side or a video decoding device on the receiving side.

On the other hand, when changing encoding parameters such as video area and scale, the video signal from the video encoding device is fixed, and the video area and scale displayed by the video decoding device on the receiving side are changed. Was.

[0005]

[Problem to be Solved by the Invention] As described above, since it is not possible to manipulate the amount of information to be transmitted in conventional video encoding and transmission devices (video encoding devices and video decoding devices), it is not possible to change the encoding parameters. Even if the amount of information decreased, the amount of information transmitted did not change, and there was a limit to the effective use of the transmission path.

The present invention provides a variable rate video encoding transmission method and variable rate video encoding transmission method that can reduce the amount of information transmitted according to changes in encoding parameters in a video encoding device on the transmitting side. It is characterized by being equipped with a device.

[0007]

[Means for Solving the Problems] A variable rate video encoding device according to claim 1 includes encoding means for encoding video information converted into digital information according to predetermined encoding parameters; A video encoding device comprising a transmitting means for packetizing and transmitting encoded video information,
The encoding means includes a control means for changing the setting of the encoding parameter to control the amount of information to be transmitted, and transmitting the encoding parameter control information to the transmitting means, and the transmitting means The present invention is characterized in that it includes a control means for packetizing the encoding parameter control information together with the video information.

The variable rate video decoding device according to claim 2 includes receiving means for processing a received signal transmitted in packets, and decoding video information from the obtained packets according to predetermined encoding parameters. In the video decoding apparatus, the receiving means includes a control means for extracting encoding parameter control information included in the packet and notifying the decoding means, and the receiving means includes a control means for extracting encoding parameter control information included in the packet and notifying the decoding means. The method is characterized in that it includes a control means for changing the setting of the encoding parameter according to the encoding parameter control information.

[0009] The variable rate video encoding and transmission method according to claim 3 encodes video information according to predetermined encoding parameters, further packetizes it and transmits it, and extracts data from received packets according to the corresponding encoding parameters. In a video encoding transmission method for decoding video information, the encoding device side changes the settings of the encoding parameters to control the amount of transmitted information, and also packetizes the changed encoding parameter control information and decodes it. The packet transmitted from the encoding device to the decoding device is provided with an area for displaying the encoding parameter control information, and the decoding device side displays the information set by the encoding device from the received packet. The feature is that encoding parameter control information is extracted and decoding is performed according to the encoding parameter.

[0010] A variable rate video encoding and transmission device according to claim 4 comprises the variable rate video encoding device according to claim 1 and the variable rate video decoding device according to claim 2. The present invention is characterized in that at least one of a quantization step width, a video area, and a video scale is used as the encoding parameter whose settings are to be changed.

[0011]

[Operation] According to the present invention, the video encoding apparatus can control the amount of transmitted information by changing the settings of encoding parameters in the encoding means. Further, the encoding parameter control information is packetized together with the encoded video information via the transmitting means, and the packet is notified to the video decoding device. Therefore, the video decoding device can extract the encoding parameter control information notified from the video encoding device and perform the corresponding decoding process. That is, a change in the encoding parameter can be recognized by both the video encoding device and the video decoding device, and the amount of information to be transmitted can be reduced by the change.

0012

Embodiment FIG. 1 is a block diagram showing the configuration of a first embodiment of a video encoding apparatus according to the present invention. In the figure, information on each pixel of the video to be transmitted is converted into a digital value and written into a frame memory 11, compressed via an encoder 12, and further quantized by a quantizer 13 to form a packet. It is input to the assembly circuit 14. The packet assembling circuit 14 packetizes the encoded and quantized video information and sends it to the transmission path.

Here, the feature of the present invention is that in this embodiment, the quantizer 13 has a plurality of quantization tables, and the corresponding quantization table is selected under the control of the quantization table control circuit 15. At the same time, the quantization table control information is sent to the packet assembling circuit 14, packetized together with the video information, sent out to the transmission path, and notified to the opposing video decoding device.

That is, the quantization table control circuit 15 controls the quantization table control circuit 15 according to settings from outside the video encoding device.
3 is selected, and the quantization step width is changed to reduce the amount of information to be transmitted. On the other hand, since the video decoding device is notified of the quantization table control information, it becomes possible to perform corresponding dequantization processing. FIG. 2 is a block diagram showing the configuration of a first embodiment of a video decoding device according to the present invention.

In the figure, a packet disassembly circuit 21 connected to the transmission line separates video information from the received packet and sends it to a dequantizer 22, and the dequantized information is sent to a decoder 23. The values of each pixel are restored and written into the frame memory 24. Note that the video information written in the frame memory 24 is converted into an analog value and displayed as a video on the display device.

Here, the feature of the present invention is that in this embodiment, the packet decomposition circuit 21 separates the quantization table control information transmitted from the video encoding device and notifies it to the dequantization table control circuit 25. At the same time, the inverse quantizer 22 is provided with a plurality of inverse quantization tables, and the corresponding inverse quantization table is selected under the control of the inverse quantization table control circuit 25.

That is, the inverse quantization table control circuit 25
can perform dequantization corresponding to the video encoding device by selecting the dequantization table of the dequantizer 22 according to quantization table control information instructed by the video encoding device. In this way, in the first embodiment of the video encoding and transmitting device shown in FIGS. 1 and 2, the amount of information to be transmitted is reduced by changing the quantization step width in the video encoding device, and the control information is By notifying the decoding device and subjecting it to dequantization processing, the transmission rate can be freely changed.

FIG. 3 is a block diagram showing the configuration of a second embodiment of the video encoding apparatus according to the present invention. In the figure,
Information on each pixel of the video to be transmitted is converted into a digital value and written into the frame memory 31, compressed via the encoder 12, further quantized by the quantizer 33, and sent to the packet assembly circuit 14. is input. The packet assembling circuit 14 packetizes the encoded and quantized video information and sends it to the transmission path.

[0019] Here, the features of this embodiment are as follows.
It is equipped with a read address control circuit 35 that controls the read address of the frame memory 31 according to video area control information indicating the size of the video to be transmitted (the number of vertical and horizontal pixels), and also includes a read address control circuit 35 that controls the read address of the frame memory 31 and transfers the video area control information to a packet assembly circuit. 14, packetized together with video information, sent out to the transmission path, and notified to the opposing video decoding device.

That is, the read address control circuit 35
Control information indicating the video area to be transmitted is set from outside the video encoding device, and the amount of information to be transmitted is reduced by converting into pixel addresses corresponding to the control information and controlling readout of the frame memory 31. On the other hand, since the video decoding device is notified of the video area control information, it is possible to perform processing corresponding to the size of the video.

FIG. 4 is a block diagram showing the configuration of a second embodiment of the video decoding apparatus according to the present invention. In the figure,
The packet decomposition circuit 21 connected to the transmission path separates video information from the received packet and sends it to the dequantizer 42, and the dequantized information is restored to the value of each pixel via the decoder 23. and written into the frame memory 44. Note that the video information written in the frame memory 44 is converted into an analog value and displayed as a video on the display device.

[0022] Here, the features of this embodiment are as follows.
The packet decomposition circuit 21 separates the video area control information transmitted from the video encoding device and notifies the write address control circuit 45, and the write address control circuit 45 divides the write address of the pixel corresponding to the size of the video into a frame. It is configured to be set in the memory 44. That is, the write address control circuit 45 specifies the write address of the frame memory 44 according to the video area control information instructed by the video encoding device, thereby performing the writing process according to the size of the video corresponding to the video encoding device. be able to.

As described above, in the second embodiment of the video encoding and transmitting apparatus shown in FIGS. 3 and 4, the amount of information to be transmitted is reduced by changing the video area in the video encoding apparatus, and
By notifying the video decoding device of the control information and having it perform the corresponding processing, the transmission rate can be changed freely. FIG. 5 is a block diagram showing the configuration of a third embodiment of the video encoding device according to the present invention.

In the figure, the configurations of a frame memory 11, an encoder 12, a quantizer 33, and a packet assembling circuit 14 are the same as in each embodiment shown in FIGS. 1 and 3. Here, the feature of this embodiment is that the frame memory 1
1 and the encoder 12, a video scale control circuit 52 is provided which outputs video scale control information for controlling the video scale circuit 51, and further transmits this video scale control information to the packet assembling circuit 14. The configuration is such that the data is sent to the video decoder, which is then packetized together with the video information, sent out to the transmission path, and notified to the opposing video decoding device.

That is, the video scale control circuit 52 outputs the corresponding video scale control information when the scale rate of the video to be transmitted is set from outside the video encoding device. The video scale circuit 51 controls the frame memory 1 based on the video scale control information.
1, and if subsampling alone cannot accurately correspond to the set scale factor, interpolation processing is performed to reduce the amount of information to be transmitted. On the other hand, the video decoding device is notified of the video scale control information (number of vertical and horizontal pixels), so
Processing that corresponds to the size of the image becomes possible.

Note that since this processing is equivalent to the second embodiment of the video encoding device shown in FIG. 3, the corresponding video decoding processing can be performed by the second embodiment of the video decoding device shown in FIG. It is. In this way, in the third embodiment of the video encoding and transmitting device shown in FIG. 5 (and FIG. 4), the video encoding device changes the scale of the video to reduce the amount of information to be transmitted, and the control information The transmission rate can be freely changed by notifying the video decoding device and having it perform the corresponding processing.

[0027]

[Effects of the Invention] As explained above, the present invention makes it possible to change the quantization step width, video area, scale, and other encoding parameters together with the video decoding device under control from the video encoding device. The amount of information to be transmitted can be reduced according to the encoding parameters. Therefore, for example, when applied to a multimedia transmission system that transmits a plurality of videos, it is possible to freely set or change bandwidth allocation according to the amount of information transmitted between media.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a first embodiment of a video encoding device according to the present invention.

FIG. 2 is a block diagram showing the configuration of a first embodiment of a video decoding device according to the present invention.

FIG. 3 is a block diagram showing the configuration of a second embodiment of the video encoding device according to the present invention.

FIG. 4 is a block diagram showing the configuration of a second embodiment of the video decoding device according to the present invention.

FIG. 5 is a block diagram showing the configuration of a third embodiment of the video encoding device according to the present invention.

[Explanation of symbols]

11 Frame memory 12 Encoder 13 Quantizer 14 Packet assembly circuit 15 Quantization table control circuit 21 Packet disassembly circuit 22 Inverse quantizer 23 Decoder 24 Frame memory 25 Inverse quantization table control circuit 31 Frame memory 33 Quantizer 35 Read address control circuit 42 Inverse quantizer 44 Frame memory 45 Write address control circuit 51 Video scaling circuit 52 Video scale control circuit

Claims (4)

[Claims] Claim 1: A video code comprising: encoding means for encoding video information converted into digital information according to predetermined encoding parameters; and transmitting means for packetizing and transmitting the encoded video information. In the encoding device, the encoding means includes a control means for controlling the amount of information to be transmitted by changing the setting of the encoding parameter, and transmitting the encoding parameter control information to the transmitting means, and the transmitting means:
A rate-variable video encoding device characterized by comprising a control means for packetizing the encoding parameter control information together with the encoded video information. 2. A video decoding device comprising: receiving means for processing a received signal packetized and transmitted; and decoding means for decoding video information from the obtained packets according to predetermined encoding parameters. In the above, the receiving means includes:
control means for extracting encoding parameter control information included in the packet and notifying the decoding means, the decoding means controlling for changing settings of encoding parameters according to the encoding parameter control information; What is claimed is: 1. A variable rate video decoding device, comprising: means. 3. A video encoding and transmission method that encodes video information according to a predetermined encoding parameter, further packetizes it and transmits it, and decodes the video information from the received packet according to the corresponding encoding parameter. The coding device changes the settings of the coding parameters to control the amount of information to be transmitted, and also packetizes the changed coding parameter control information and transmits it to the decoding device. An area for displaying the encoding parameter control information is provided in the packet to be transmitted, and the decoding device extracts the encoding parameter control information set by the encoding device from the received packet and uses the encoding parameter in the received packet. A variable rate video encoding and transmission method characterized by decoding according to the rate. 4. A variable rate video encoding device according to claim 1 and a variable rate video decoding device according to claim 2, wherein the encoding parameters to be changed include a quantization step width, A variable rate video encoding/transmission device characterized by using at least one of a video area and a video scale.