VAD(Voice Activity Detector) python 实现对读入的流式数据, 进行端点检测
依赖 pyaudio http://people.csail.mit.edu/hubert/pyaudio/
Distributor ID: Ubuntu Description: Ubuntu 12.04.5 LTS Release: 12.04 Codename: precise
Linux ubuntu 3.13.0-32-generic #57~precise1-Ubuntu SMP Tue Jul 15 03:51:20 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux Python 2.7.3