libavformat/flvdec.c:388: error: Uninitialized Value
  The value read from is_audio was never initialized.

libavformat/flvdec.c:388:8: 
386.     }
387. 
388.     if(is_audio){
            ^
389.         if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample || (!st->codec->codec_id && !st->codec->codec_tag)) {
390.             st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
