stream->fmt = ffserver_guess_format(NULL, stream->filename, NULL);
avcodec_get_context_defaults2(&video_enc, AVMEDIA_TYPE_VIDEO);
avcodec_get_context_defaults2(&audio_enc, AVMEDIA_TYPE_AUDIO);
stream->fmt = ffserver_guess_format(NULL, stream->filename, NULL);
avcodec_get_context_defaults2(&video_enc, AVMEDIA_TYPE_VIDEO);
avcodec_get_context_defaults2(&audio_enc, AVMEDIA_TYPE_AUDIO);