pcap截包文件结构分析，将RTP视频数据提取出，可以分析码率，帧率，和丢包率-pcap file structure analysis cut-off

VideoSnarf version 0.63. VideoSnarf is a new security assessment tool that takes an offline pcap as input, and outputs any detected media streams (RTP sessions), including common audio codecs as well as H264 Video support.