KR0176091B1 - Method of processing a video stream in a multimedia board for a multipoint desktop video conferencing - Google Patents

Abstract

The present invention relates to a method for processing a video stream in a multimedia board for multi-party desktop video conferencing. The present invention relates to a method for processing a video stream in a multimedia board in which a video stream processor is dualized in a video stream compression / restore unit. Initializes each hardware component in the multimedia board, loads the microcode required to perform compression / restore of the video stream compression / restoration to the processors 1 and 2, and sets the necessary parameters for video compression / restore to drive the processor. Making a first process; A second process of the processor 1 performing a compression process to compress the video stream according to the driving of the processor 1 of the first process; A third step of performing the reconstruction processing by the processor 2 to reconstruct the video stream according to the driving of the processor 2 of the first step; The processor 1 and 2 perform a process of compressing and reconstructing each of the processors through mode conversion for multi-view video and video processing. It is possible to improve the quality of multi-party desktop video conferencing by compressing one video stream inputted by a video signal and simultaneously converting and compressing a compressed video stream received through a communication network according to a two- or three-party conference.

Description

Video Stream Processing Method in Multimedia Board for Multi-Party Desktop Video Conference

1 is a hardware block diagram of a multimedia board according to the present invention.

2 is a video flow processing flowchart according to the present invention.

3 is a flow chart for compression processing during video stream processing of FIG.

4 is a flowchart for reconstruction processing during video stream processing of FIG.

* Explanation of symbols for main parts of the drawings

10: video signal input unit 20: video overlay / output unit

30: video stream compression / restoration unit 40: audio input unit

50: audio output unit 60: PC matching unit

The present invention relates to a method for processing a video stream in a multimedia board for multi-party desktop video conferencing. The present invention relates to a multimedia board in which a video stream processor in a video stream compression / restore unit is dualized to compress one input video stream. At the same time, a video stream processing method in a multimedia board for multi-party desktop video conference, which enables high-quality multi-party desktop video conference by dynamically modulating and restoring a compressed video stream received through a communication network according to a 2- or 3-way conference. It is about.

In general, a multi-party desktop video conferencing system is a system that allows multiple meeting participants to conduct a meeting using a networked computer on their desks without having to go to the meeting place for the meeting.

Using this system, each meeting participant can call a meeting participant who wants to have a meeting on his or her computer, and have a meeting while watching the participant's picture on his monitor screen.

In addition, the system receives the participant's appearance and voice from the camera and the microphone connected to the computer, and digitalizes it in the computer, and delivers it to other participants' computers through a general telephone network or a computer communication network. Show them on a computer on the participants' desks, allowing them to conduct meetings.

In this case, when all attendees digitalize video and audio and exchange them with a communication network, the amount of data transmitted is out of the range of the current transmission bandwidth of a general computer network, and thus a meeting cannot be conducted in real time.

Therefore, in a multi-party desktop video conferencing system, a real-time video data input / output function and a compression / restore function of video data are required to support video conferencing in real time in a current computer communication network.

In particular, the functions required for multi-party desktop video conferencing support include real-time input and compression of video signals input through the camera, real-time reconstruction of multiple compressed video streams received through a communication network, and monitoring of input and reconstructed video streams. Simultaneous output is also required, and simultaneous input and encoding of a voice signal input through a microphone, decoding of encoded voice data, and a mixed output function of a microphone input voice signal and a decoded voice signal are also required.

The video stream processing in the conventional desktop video conferencing multimedia board is limited in compression / restore performance of the video data, so that only one video stream received through the communication network can be restored in the compressed and compressed state. have.

Accordingly, the compressed video stream is controlled by the application program for the multi-party video conference.

However, as a result of the control, the frame rate of the video image is low, and thus the motion of the video is not natural. When displaying the video data on the monitor, only one video is output or the screen size is small even when the screens of several participants are displayed. The frame rate was also low, there was a problem that can not provide enough video.

An object of the present invention for solving the above problems is to compress one video stream input from a multimedia board in which the video stream processor in the video stream compression / restore unit is duplexed in parallel, and at the same time according to a two- or three-way conference The present invention provides a method for processing a video stream in a multimedia board for multi-party desktop video conferencing capable of enabling high-definition and high-quality multi-degree desktop video conferencing by dynamically modulating and restoring a compressed video stream received through a video. have.

A feature of the present invention for achieving the above object is a method for processing a video stream in a multimedia board in which a video stream processor is duplexed in parallel in a video stream compression / recovery unit. A first step of initializing, loading microcodes necessary to perform compression / restore of the video stream compression / restore unit to the processors 1 and 2, and setting parameters necessary for video compression / restore to drive the processor; A second process of the processor 1 performing a compression process to compress the video stream according to the driving of the processor 1 of the first process; A third step of performing the reconstruction processing by the processor 2 to reconstruct the video stream according to the driving of the processor 2 of the first step; In order to process a multi-view video and video, the processor 1 and 2 perform a compression and decompression process through a mode conversion.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a hardware block diagram of a multimedia board used for multi-party desktop video conferencing according to the present invention. The board includes a video signal input unit 10, a video overlay / output unit 20, and a video stream compression / restore unit 30. , An audio input unit 40, an audio output unit 50, and a PC matching unit 60.

The video signal input unit 10 converts a video signal input from a camera into a data format that can be processed by a computer, and the video overlay / output unit 20 compresses / restores a video stream with the video signal input unit 10. The three video streams input from the unit 30 are overlaid on the graphic data input from the graphics board.

The video stream compression / recovery unit 30 compresses the video stream input from the video signal input unit 10 and delivers the video stream to the PC. At the same time, the other video stream is received from the PC and restored through the PC. Output to the digital video processor 108 of the video overlay / output unit 20.

The audio input unit 40 digitalizes the analog voice signal input from the microphone and passes it to the PC. The audio output unit 50 receives the coded voice stream from the PC, decodes it, and converts the analog voice signal into an analog voice signal. Output

The PC matching unit 60 is a matching unit for communication between the multimedia board and the PC, so that the compressed video streams and coded voice streams processed by the board can be exchanged with the PC.

The compression / restore method according to the present invention improves the compatibility of compressed video data streams by following the ITU-TS H.261 standard, and performs video stream control processing suitable for the characteristics of this standard.

FIG. 2 is an overall flowchart of video stream processing for implementing multi-party video conferencing by driving the hardware of FIG. 1. First, the hardware initialization module step S201 is a module for initializing to a state necessary for driving the hardware of FIG. 1. The video signal input unit, video overlay / output unit, and video stream compression / recovery unit of FIG. 1 are initialized, data and code memory initialization, data transmission / reception queue and stack initialization, interrupt and DMA initialization are performed.

Subsequently, in the microcode download module step S202, the microcodes required to perform compression / restore are downloaded to the videostream processor 1101 and the videostream processor 2102 in the videostream compression / restore unit 30, respectively. As a module, the microcode consists of a data portion and a code portion, which are downloaded to the code memories 103 and 105 by direct writing to a memory and then subjected to the code. The data portion is downloaded to 104,106.

In the next initial parameter setting module step (S203), the processor 1 and the processor 2 are driven to perform compression and restoration on the processor 1 and the processor 2 after setting initial parameters required for compression / restore of the video stream.

The compression module step (S204) performed by the processor 1 is shown in FIG. 3, and the restoration modules (S205 and S206) performed by the processor 1 and the processor 2 will be described in detail with reference to FIG.

Subsequently, the mode conversion module steps S207 and S208 are processing modules for further increasing image quality since the image processing function is improved when one compression or restoration is performed, rather than the simultaneous compression and restoration in one processor. In case of restoring from one processor according to the state of multi-conference video conferencing, mode 1 is divided into mode 2 when both processors restore. In mode 1, compression is performed on processor 2 and mode 2 is restored. In 2, compression and decompression is performed on processor 1 and restoring is performed on processor 2.

That is, when the mode 1 is converted to the mode 2, the restoration process of the processor that has not been restored is additionally performed. When the mode 2 is converted to the mode 1, the restoration is desired to be stopped by checking the restoration processing unit to be stopped. If the processor is processor 1, the processor 1 only needs to stop the compression process. However, if the compression process to be stopped is processor 2, the processor 1 and the processor 2 that are currently being processed are stopped and the video stream processed by the processor 1 is received. After preparing for processing in step 2, resume the restoring process of processor 2 and request the other side to compress the restored video stream to restart compression, and the position of the output video stream of the processor through the MUX 107 through processor 1 The location of the output on the monitor The.

3 is a flowchart for compressed stream processing performed by the processor 1 of FIG. 2, and the parameter setting module steps S301 and S302 set parameters according to a user's request, and the restart request module steps S303 and S304. Will resume compression from the beginning when it receives a restart request.

Subsequently, in the compression end module steps S305 and S306, if the compression end request is received, this ends.

In the compressed data read module step (S307, S308, S309), if the current compressed data is being read or there is a request to read the compressed data, the amount of data to be read is calculated first, and whether the data is ready for data communication by the processor 1 and the DMA. If it is prepared by checking the information, the compressed data amount information prepared from the processor 1 is obtained, and the data amount is read by DMA.

In the compressed data read end module step (S310, S311, S312), when the compressed data is read, the total read data amount is satisfied compared to the user's read demand (S310) or whether the total read time exceeds the predetermined time (S311). If exceeded, the reading of the compressed data is terminated (S312).

The time delay module step (S313) is inserted to reduce the working time of the processor by preventing repeating of the compression routine too frequently.

4 is a flowchart for reconstructed stream processing in the processor 1 and the processor 2. The parameter setting module steps S401 and S402 analyze the user's request or the input video stream and set necessary parameters.

In the restoration termination module steps S403, S404, and S405, when there is a request for terminating compression restoration, the initial processing is performed so that the initial screen data necessary to remove the afterimage of the previous screen may be used in the frame buffer in the next restoration.

The restore data write module step (S406, S407, S408) is currently writing the restore data or if there is a request to write the restore data, it first calculates the amount of data to write and checks if the data communication is ready by the processor and the DMA. If it is ready to check whether the recovery data required by the processor is obtained, this data amount is used by DMA.

Restoration data write end module steps (S409, S410), after the completion of restoration data writing, if the total amount of data written is satisfied in comparison with the user's requirement (S409), the restoration data writing ends.

The time delay module step (S411) is inserted to reduce the working time of the processor by preventing the repetition of too many recovery routines.

As described above, the present invention compresses one video stream inputted by the paralleled and redundant video stream processors 1 and 2 of a multimedia board, and simultaneously receives a compressed video stream received through a communication network according to a two or three party conference. By dynamically modulating and restoring, you can improve the quality of multi-party desktop video conferencing.

Claims (1)

A method of processing a video stream in a multimedia board in which a video stream processor is duplexed in parallel in a video stream compression / recovery unit, the method comprising: initializing each hardware component in the multimedia board, and performing compression / restore of the video stream compression / restore unit. A first step of loading the microcode required for execution into the processors 1 and 2 and setting the parameters necessary for video compression / restore to drive the processor; A second process of the processor 1 performing a compression process to compress the video stream according to the driving of the processor 1 of the first process; A third step of performing the reconstruction processing by the processor 2 to reconstruct the video stream according to the driving of the processor 2 of the first step; The video stream in the multimedia board for multi-party desktop video conferencing, which is performed by the processor 1 and 2 performing a respective compression and reconstruction process through mode conversion for multi-view video and video processing. Treatment method.