说明：  Mp3解码过程,总体上可分为9个过程：比特流分解，霍夫曼解码，逆量化处理，立体声处理，频谱重排列，抗锯齿处理，IMDCT变换，子带合成，pcm输出。
(Mp3 decoding process, on the whole can be divided into nine process: bit-stream decomposition, Huffman decoding, inverse quantization processing, sound processing, spectrum re-arrangement, antialiasing, IMDCT transform, sub-band synthesis, pcm output.)