[FFmpeg-cvslog] vc1dec: Don't decode slices when the latest slice header failed to decode

[Michael Niedermayer]

ffmpeg | branch: release/0.10 | Michael Niedermayer <michaelni at gmx.at> | Tue Feb 19 21:40:09 2013 +0100| [c00e491aebecd3257cccb41c56029996146727d2] | committer: Luca Barbato

vc1dec: Don't decode slices when the latest slice header failed to decode

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable at libav.org
Signed-off-by: Martin Storsjö <martin at martin.st>

Conflicts:
	libavcodec/vc1dec.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c00e491aebecd3257cccb41c56029996146727d2
---

 libavcodec/vc1dec.c |   18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c
index cf960f6..2d193c1 100644
--- a/libavcodec/vc1dec.c
+++ b/libavcodec/vc1dec.c
@@ -5579,6 +5579,8 @@ static int vc1_decode_frame(AVCodecContext *avctx, void *data,
         if (avctx->hwaccel->end_frame(avctx) < 0)
             goto err;
     } else {
+        int header_ret = 0;
+
         ff_er_frame_start(s);
 
         v->bits = buf_size * 8;
@@ -5623,13 +5625,21 @@ static int vc1_decode_frame(AVCodecContext *avctx, void *data,
             }
             if (i) {
                 v->pic_header_flag = 0;
-                if (v->field_mode && i == n_slices1 + 2)
-                    vc1_parse_frame_header_adv(v, &s->gb);
-                else if (get_bits1(&s->gb)) {
+                if (v->field_mode && i == n_slices1 + 2) {
+                    if ((header_ret = vc1_parse_frame_header_adv(v, &s->gb)) < 0) {
+                        av_log(v->s.avctx, AV_LOG_ERROR, "Field header damaged\n");
+                        continue;
+                    }
+                } else if (get_bits1(&s->gb)) {
                     v->pic_header_flag = 1;
-                    vc1_parse_frame_header_adv(v, &s->gb);
+                    if ((header_ret = vc1_parse_frame_header_adv(v, &s->gb)) < 0) {
+                        av_log(v->s.avctx, AV_LOG_ERROR, "Slice header damaged\n");
+                        continue;
+                    }
                 }
             }
+            if (header_ret < 0)
+                continue;
             s->start_mb_y = (i == 0) ? 0 : FFMAX(0, slices[i-1].mby_start % mb_height);
             if (!v->field_mode || v->second_field)
                 s->end_mb_y = (i == n_slices     ) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);