libavformat/flvdec.c:808: error: Uninitialized Value
  The value read from is_audio was never initialized.

libavformat/flvdec.c:808:9: 
806.     }
807. 
808.     if (is_audio) {
             ^
809.         int bits_per_coded_sample;
810.         channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
