libavcodec/fmvc.c:354: error: Uninitialized Value
  The value read from opcode was never initialized.

libavcodec/fmvc.c:354:13: 
352.                 break;
353.             bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
354.             pos = (-((opcode & 0x1F) | 32 * bytestream2_get_byte(gb)) - 1);
                 ^
355.             bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
356.             bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
