From 746016598d1885afd1fee976b6d315ed7eeefa68 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 30 Mar 2013 16:04:07 +0100 Subject: [PATCH] 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 --- libavcodec/h264.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/libavcodec/h264.c b/libavcodec/h264.c index a736070f0f..21da19fbf6 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); imb_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;