webrtc基础音频信号处理，以及CNG模块提取，并向其中附加了G7221C编解码器，用于处理7221音频数据和VAD活动语音检测后的CNG包，用于服务器处理流媒体数据，混音等的操作。-webrtc base audio signal processing, as well as CNG module extracts, to which is added G7221C codec 7221 for processing audio data and voice activity detecti

g7221c的编解码库可以用来编解码，好用(g7221c decode and encode sample)