libavcodec/mjpegdec.c:881: error: Uninitialized Value
  The value read from linesize[_] was never initialized.

libavcodec/mjpegdec.c:881:25: 
879. 
880.                     if (s->interlaced && s->bottom_field)
881.                         block_offset += linesize[c] >> 1;
                             ^
882.                     ptr = data[c] + block_offset;
883.                     if (!s->progressive) {
