[FFmpeg-cvslog] ljpegdec: support non zero MCU for RGB. 2nd try

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Fri Jan  6 19:03:21 2012 +0100| [bbe25b4f3ebb5f7436d066a787e9ebf964aca1d0] | committer: Michael Niedermayer

ljpegdec: support non zero MCU for RGB. 2nd try

Fixes Ticket875
Compared to patch 1 this fixes a bright line at the right side.

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bbe25b4f3ebb5f7436d066a787e9ebf964aca1d0
---

 libavcodec/mjpegdec.c |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 58bbd63..c0c4080 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -684,6 +684,8 @@ static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int nb_components, int p
     int left[3], top[3], topleft[3];
     const int linesize= s->linesize[0];
     const int mask= (1<<s->bits)-1;
+    int resync_mb_y = 0;
+    int resync_mb_x = 0;
 
     av_fast_malloc(&s->ljpeg_buffer, &s->ljpeg_buffer_size, (unsigned)s->mb_width * 4 * sizeof(s->ljpeg_buffer[0][0]));
     buffer= s->ljpeg_buffer;
@@ -692,7 +694,6 @@ static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int nb_components, int p
         buffer[0][i]= 1 << (s->bits - 1);
     }
     for(mb_y = 0; mb_y < s->mb_height; mb_y++) {
-        const int modified_predictor= mb_y ? predictor : 1;
         uint8_t *ptr = s->picture.data[0] + (linesize * mb_y);
 
         if (s->interlaced && s->bottom_field)
@@ -702,8 +703,17 @@ static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int nb_components, int p
             top[i]= left[i]= topleft[i]= buffer[0][i];
         }
         for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
-            if (s->restart_interval && !s->restart_count)
+            int modified_predictor = predictor;
+
+            if (s->restart_interval && !s->restart_count){
                 s->restart_count = s->restart_interval;
+                resync_mb_x = mb_x;
+                resync_mb_y = mb_y;
+                for(i=0; i<3; i++)
+                    top[i]= left[i]= topleft[i]= 1 << (s->bits - 1);
+            }
+            if (mb_y == resync_mb_y || mb_y == resync_mb_y+1 && mb_x < resync_mb_x)
+                modified_predictor = 1;
 
             for(i=0;i<nb_components;i++) {
                 int pred, dc;