libavformat/flvdec.c:393: error: Uninitialized Value
  The value read from is_audio was never initialized.

libavformat/flvdec.c:393:8: 
391.     }
392. 
393.     if(is_audio){
            ^
394.         if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
395.             st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
