变换音频编码预回声产生机理与抑制方法

Principle of Pre-echo and Control Methods in Transform Audio Coding

针对变换音频编码中的预回声问题,阐述了预回声的概念及产生机理,分析了预回声抑制方法的原理与实现手段.提出了基于时域拆分——频域合成的预回声处理算法,与窗切换及比特池等预回声处理技术相比,可以减小算法延迟,并取得良好的预回声抑制效果.

Aiming at the pre-echo problem in transform audio coding, the concept and principle of pre- echo was explained, and several schemes to control pre-echo distortion were presented with their basic ideas and implementary approaches. A new algorithm of reducing pre-echo utilizing time domain analysis and fre- quency domain synthesis psychoacoustics model was proposed, which, compared with window switching and bit reservoir technologies, can lower the algorithm delay and achieve a good effect of pre-echo reduction.