Research On Digital Signal Processing Based On Video Conferencing Multipoint Control Unit

The video conferencing system is a set of computer, communications and microelectronics technology,which is an multi-party remote off-site communication. In the course of development of video conferencing systems, how to improve the quality of video conferencing, voice and image transmission has become the primary task of the scientific research of the video conference system.Digital signal processing is the key of output of high-quality voice and image of video conferencing system, G.723codec standard audio codec standard as a video conferencing system in the H.323protocol stack, has a pivotal role in the video conferencing system, high-qualitythe audio codec is the essence of the agreement, and low-rate speech coder saves a lot of bandwidth. A high performance algorithm can not only improve the quality of the conference call, but also can bring huge economic benefits. G.723audio codec protocol is the main study object of this paper. Based on the application of the function of the multi-point control unit (MCU) core processor, the paper presents several optimization programs and test through simulation experiment for the implemented of G.723codec algorithm on the MCU, this main contents of the paper are as follows:1-Study and analysis the basic architecture of the video conferencingRe system and the main ways of audio codec, to understand the structure and function of the MCU.2Understand the structure, principles and mathematical models of G.723coding algorithm system, study code excited linear prediction algorithm in-depth. Based on the the reasearch of algorithms,the paper proposed algorithm level C code level, assembly-level optimization scheme to improve the efficiency of compiled code, reduce the complexity of the algorithm through the introduction of the First-Forecast ACELP algorithm.3Based on G.723decoding algorithm, the article put in the LMS noise cancellation algorithm to improve the quality of voice calls.4The article analysis the gathered data of the experimental throngh the VS2010,the CCS software platform and MATLAB experimental tests,The experimental results show that, coding results are normal throngh the analysis and testing of the optimized result, which can process multi-channel voice synthesis normally, and has improved the run rate and voice quality, and achieved the desired effect.