[FFmpeg-cvslog] avcodec/mjpegdec: Fix decoding RGBA RCT LJPEG

[Michael Niedermayer]

ffmpeg | branch: release/2.5 | Michael Niedermayer <michael at niedermayer.cc> | Fri Sep 11 13:28:51 2015 +0200| [93fc958f22499c37bfa5fb9bfd89e2eb75df3bc7] | committer: Michael Niedermayer

avcodec/mjpegdec: Fix decoding RGBA RCT LJPEG

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 055e56e9f76da3298f1b59bf5ea46f570e844600)

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=93fc958f22499c37bfa5fb9bfd89e2eb75df3bc7
---

 libavcodec/mjpegdec.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index af38364..1edbe5d 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -971,7 +971,14 @@ static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int nb_components, int p
                 skip_bits(&s->gb, 16); /* skip RSTn */
             }
         }
-        if (s->nb_components == 4) {
+        if (s->rct && s->nb_components == 4) {
+            for (mb_x = 0; mb_x < s->mb_width; mb_x++) {
+                ptr[4*mb_x + 2] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2] - 0x200) >> 2);
+                ptr[4*mb_x + 1] = buffer[mb_x][1] + ptr[4*mb_x + 2];
+                ptr[4*mb_x + 3] = buffer[mb_x][2] + ptr[4*mb_x + 2];
+                ptr[4*mb_x + 0] = buffer[mb_x][3];
+            }
+        } else if (s->nb_components == 4) {
             for(i=0; i<nb_components; i++) {
                 int c= s->comp_index[i];
                 if (s->bits <= 8) {