The Implementation Of LD-AAC Coder Based On TM1300

MPEG-4 Audio Version2 specifies a Low-Delay Advanced Audio Codec to reduce the algorithmic delay to not exceeding 20 ms. This paper presents the theory of low delay advanced audio coding algorithms and analyzes the key technical issues and the implementation of them. Firstly, some improvements of LD-AAC coder based on PC platform are made by this paper, which are mostly concentrated on the decreasing of the computational complexity without any influence on the coding quality. The main improvements are as followings: fast MDCT , IMDCT algorithms; simplified quantization module; and improved LTP module. Then, a LD-AAC encoder was realized on the Digital Signal Processor TM1300.Finally, experimental results have shown that all the improvements show an excellent performance in calculating speed and stability.