libavcodec/fmvc.c:331: error: Uninitialized Value
  The value read from opcode was never initialized.

libavcodec/fmvc.c:331:21: 
329.                 do {
330.                     bytestream2_put_byte(pb, bytestream2_get_byte(gb));
331.                     --opcode;
                         ^
332.                 } while (opcode && bytestream2_get_bytes_left(gb) > 0);
333. 
