The Research Of Algorithms Of AVS Audio Coding And The Realization On DSP

AVS audio standard is the third part of AVS (Audio and Video coding Standard), which is of our own independent intellectual property, it provides a good way to the field of high quality audio compression. And it applies to the high-resolution digital broadcast, high-density laser digital storage medium, wireless wide-band multimedia communication, broad band internet streaming media application and so on. There are many advanced technology on audio coding in AVS audio standard. It has great significance on the spread and applications of AVS audio standard to do the research on the algorithms and realization in real time of AVS audio coding.The thesis introduces the development and the fundamental principle of audio coding technology. The standard modules of AVS audio and the algorithm of each module are studied and analyzed. It could be found that the computational complexity of AVS audio coding is very high when transient signals are processed. Thus, two new methods are presented in place of the original method. It is proved by experimentation based on AVS that the audio quality of new methods is the same as the quality of the original method. But the computational complexity of AVS audio encoder and decoder are greatly decreased in the new methods.After the analysis of the algorithms of AVS audio, the thesis optimizes all modules of AVS audio so as to decrease the computational complexity of encoder and decoder greatly. After that, the porting and optimization of AVS audio encoder is presented based on DM642 EVM, including audio capturing, encoding, and bit stream transmitting in real time. And the porting and optimization of AVS audio decoder is presented based on DSK5416, including bit stream receiving, decoding and playing in real time. The encoder can encode the audio samples in real time with the sampling rate of 44.1kHz at 150MHz cycles while the decoder at 25MHz cycles.Finally, the thesis introduces the purpose and necessity of audio conformance testing and sums up the parameters that are necessary to be tested. And the method to generating bit streams which are used to test decoder is given at last.