The Research And Implementation Of SVAC Audio Codec

Audio and video monitoring system occupies an important position in the prevention and control system of social security. Currently , existing audio coding standards are all used for at radio and television and popular entertainment applications, if they are used directly in the field of safety precautions, there are some non-adaptive. And in the domestic and international, there is no audio video coding standards designed for security video surveillance. So from 2007, our country organizes relevant departments and experts, to summarize the special needs of security surveillance, research and draft the surveillance video and audio coding-SVAC.SVAC Audio coding standard, is drafted by national security precautions alarm system standardization technical committee. It is specially used in The field of security monitoring, and now it is still in the phase of the study. It solves the problem that there is no unified standard in the The field of security monitoring, and meets the demand of security precautions. It also can get rid of the patent trap of foreign standards, more conducive to the domestic video surveillance market.This first briefly introduce the development of Audio and video surveillance and some audio coding standerds. Secondly the fundamental knowledge theory of audio coding will be introduced in details, including some key theories, For example LPC, TCX, ACELP, and so on. And then the article expatiates the architecture framework and coding theory of SVAC. After that, the error and lost frame concealment is added to SVAC, for now SVAC has no ability to deal with the error/lost frame data. At last the subjective and objective evaluations for SVAC encoding quality, anti-noise ability, and the quality of error and lost frame concealment module has been done.