MPEG音频解码中子带合成滤波器的快速算法及定点DSP实现

Fast Algorithm of Subband Synthesis Filter Banks for Decoding of Digital Audio and Its Implementation on Fixed Point DSP Chip

高质量的数字音频编解码一般都采用频域子带编解码算法 .以 MPEG- 2 Audio Layer 标准为基础 ,推导了在高质量数字音频编解码算法的子带合成滤波器模块中改进的反向离散余弦变换 ( IMDCT)快速算法 ,并讨论了加窗运算的技巧及其在定点数字信息处理 ( DSP)中实现的具体方法 .在保证运算精度的前提下 ,该基于 IDCT的快速算法在 DSP实时实现中大约可减少 2 /3的运算量与

Subband synthesis filter bank is an important module in high quality audio codec. This paper presented a fast IMDCT algorithm based on MPEG2 Audio Layer Ⅲ. And it introduced an efficient windowing tricky method. The implementation ideal based on fixed point DSP chip was also covered in this paper. While guaranteeing the computing precision, the proposed algorithm and windowing method can reduce lots of computational complexity and memory requirements.