jpegdec: actually search for and parse RSTn
authorMichael Niedermayer <michaelni@gmx.at>
Thu, 9 Jun 2011 01:35:50 +0000 (03:35 +0200)
committerReinhard Tartler <siretart@tauware.de>
Sat, 23 Jul 2011 17:19:13 +0000 (19:19 +0200)
Fixes decoding of MJPEG files produced by some UVC Logitec web cameras,
such as "Notebook Pro" and "HD C910".

References:
http://trac.videolan.org/vlc/ticket/4215
http://ffmpeg.org/trac/ffmpeg/ticket/267

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Reviewed-by: Kostya <kostya.shishkov@gmail.com>
(cherry picked from commit 7b8ed831eb8432d202dad16dedc1758b018bb1fa)

libavcodec/mjpegdec.c

index b28fdf8..7eea6d7 100644 (file)
@@ -879,9 +879,12 @@ static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah, i
                 }
             }
 
-            if (s->restart_interval && !--s->restart_count) {
+            if (s->restart_interval && show_bits(&s->gb, 8) == 0xFF){ /* skip RSTn */
+                --s->restart_count;
                 align_get_bits(&s->gb);
-                skip_bits(&s->gb, 16); /* skip RSTn */
+                while(show_bits(&s->gb, 8) == 0xFF)
+                    skip_bits(&s->gb, 8);
+                skip_bits(&s->gb, 8);
                 for (i=0; i<nb_components; i++) /* reset dc */
                     s->last_dc[i] = 1024;
             }