MPEG-2 AAC解码器的优化算法

Optimized Algorithm of MPEG-2 AAC Decoder

作为新一代的音频编码国际标准,先进音频编码(AAC)提供了良好的压缩性能,具有广阔的发展和应用前景。但是由于AAC标准给出的算法比较复杂,按照标准算法进行测试时发现其并不能满足实时解码的要求,因此,必须对标准算法进行优化以达到实时解码的要求。在叙述了MPEG-2 AAC解码器的模块组成和原理的基础上,针对各个模块的特点采用优化算法,对MPEG-2 AAC解码器的部分模块进行了优化设计,较大程度地提高了解码速度。

As a new generation international standard of audio coding, the Advanced Audio Coding （AAC） supplies good compression performance,it has a wide prospect of development and application. However, we find it can not satisfy the requirement of real- time decoding because of the complexity of the algorithm presented by AAC standard,so we must optimize the algorithm presented by AAC standard in order to satisfy the requirement of real time decoding. In this article, the principle and constitution of MPEG - 2 AAC decoder is described. Adopting optimized algorithm according to characteristic of each module, we optimize part modules of MPEG- 2 AAC decoder,and increase speed of decoding greatly.