libavcodec/mjpegdec.c:848: error: Uninitialized Value
  The value read from linesize[_] was never initialized.

libavcodec/mjpegdec.c:848:29: 
846.                     if(!s->progressive) {
847.                         if (copy_mb) {
848.                             mjpeg_copy_block(ptr, reference_data[c] + block_offset, linesize[c], s->avctx->lowres);
                                 ^
849.                         } else {
850.                         s->dsp.clear_block(s->block);
