mjpegdec: Handle RSTn in progressive jpegs

Fixes Ticket2003
Reviewed-by: Alexander Strasser <eclipse7@gmx.net>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mjpegdec.c

@@ -1141,6 +1141,9 @@ static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss,
         uint8_t *last_nnz    = &s->last_nnz[c][block_idx];
         for (mb_x = 0; mb_x < s->mb_width; mb_x++, block++, last_nnz++) {
                 int ret;
+                if (s->restart_interval && !s->restart_count)
+                    s->restart_count = s->restart_interval;
+
                 if (Ah)
                     ret = decode_block_refinement(s, *block, last_nnz, s->ac_index[0],
                                                   quant_matrix, ss, se, Al, &EOBRUN);
@@ -1157,6 +1160,7 @@ static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss,
                     s->dsp.idct_put(ptr, linesize, *block);
                     ptr += 8 >> s->avctx->lowres;
             }
+            handle_rstn(s, 0);
         }
     }
     return 0;