[FFmpeg-cvslog] h264: Move slice_table clean out of frame_start
Michael Niedermayer
git at videolan.org
Sat Mar 30 20:42:54 CET 2013
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Mar 30 16:04:07 2013 +0100| [746016598d1885afd1fee976b6d315ed7eeefa68] | committer: Michael Niedermayer
h264: Move slice_table clean out of frame_start
Fixes inconsistency ultimately leading to an out of array read
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=746016598d1885afd1fee976b6d315ed7eeefa68
---
libavcodec/h264.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index a736070..21da19f 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -1864,11 +1864,6 @@ static int h264_frame_start(H264Context *h)
h->block_offset[48 + 32 + i] = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 8 * h->uvlinesize * ((scan8[i] - scan8[0]) >> 3);
}
- /* Some macroblocks can be accessed before they're available in case
- * of lost slices, MBAFF or threading. */
- memset(h->slice_table, -1,
- (h->mb_height * h->mb_stride - 1) * sizeof(*h->slice_table));
-
// s->decode = (h->flags & CODEC_FLAG_PSNR) || !s->encoding ||
// h->cur_pic.reference /* || h->contains_intra */ || 1;
@@ -3563,6 +3558,15 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
} else {
release_unused_pictures(h, 0);
}
+ /* Some macroblocks can be accessed before they're available in case
+ * of lost slices, MBAFF or threading. */
+ if (FIELD_PICTURE(h)) {
+ for(i = (h->picture_structure == PICT_BOTTOM_FIELD); i<h->mb_height; i++)
+ memset(h->slice_table + i*h->mb_stride, -1, (h->mb_stride - (i+1==h->mb_height)) * sizeof(*h->slice_table));
+ } else {
+ memset(h->slice_table, -1,
+ (h->mb_height * h->mb_stride - 1) * sizeof(*h->slice_table));
+ }
}
if (h != h0 && (ret = clone_slice(h, h0)) < 0)
return ret;
More information about the ffmpeg-cvslog
mailing list