语音识别前期处理代码，包括语音信号预处理，预加重，加窗分帧，短时能量及短时平均幅度分析，短时平均过零率，短时自相关分析，短时平均幅度差函数。-Speech recognition pre-processing code, including voice signal pre-processing, pre-emphasis, windowing sub-frame, and the short-term average short-term energy analysis, the average short-term zero-crossing rate, short-term autocorrelation analysis, short-term average magnitude difference function.