libavformat/flvdec.c:909: error: Uninitialized Value
  The value read from is_audio was never initialized.

libavformat/flvdec.c:909:9: 
907.         }
908.     }
909.     if (is_audio && (sample_rate != flv->last_sample_rate ||
             ^
910.                      channels    != flv->last_channels)) {
911.         flv->last_sample_rate = sample_rate;
