检查demux的支持哪些format状况
AVInputFormat *av_i = av_iformat_next(NULL); while(av_i) { printf("name:%s\n", av_i->name); av_i = av_iformat_next(av_i); }
ffmpeg 检查demux codec
原文：http://www.cnblogs.com/ranson7zop/p/7061530.html
