From f96fdb46b773eadcfa5de34e800ec456c0e545b9 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 8 Apr 2015 12:29:47 +0200 Subject: [PATCH] avcodec/h264_slice: Dont reset mb_aff_frame per slice Fixes null pointer dereference Fixes Ticket4440 Signed-off-by: Michael Niedermayer (cherry picked from commit 386601286fed2dff5e1955bc21a0256f6f35ab19) Conflicts: libavcodec/h264_slice.c (cherry picked from commit ce6d38e9ed0842870f3cd5414937bb6d1f2417d9) --- libavcodec/h264_slice.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c index 560b24f9e6..b667da3956 100644 --- a/libavcodec/h264_slice.c +++ b/libavcodec/h264_slice.c @@ -1307,6 +1307,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264Context *h0) int field_pic_flag, bottom_field_flag; int first_slice = h == h0 && !h0->current_slice; int frame_num, picture_structure, droppable; + int mb_aff_frame, last_mb_aff_frame; PPS *pps; h->qpel_put = h->h264qpel.put_h264_qpel_pixels_tab; @@ -1531,7 +1532,8 @@ int ff_h264_decode_slice_header(H264Context *h, H264Context *h0) } h->mb_mbaff = 0; - h->mb_aff_frame = 0; + mb_aff_frame = 0; + last_mb_aff_frame = h0->mb_aff_frame; last_pic_structure = h0->picture_structure; last_pic_droppable = h0->droppable; droppable = h->nal_ref_idc == 0; @@ -1549,12 +1551,13 @@ int ff_h264_decode_slice_header(H264Context *h, H264Context *h0) picture_structure = PICT_TOP_FIELD + bottom_field_flag; } else { picture_structure = PICT_FRAME; - h->mb_aff_frame = h->sps.mb_aff; + mb_aff_frame = h->sps.mb_aff; } } if (h0->current_slice) { if (last_pic_structure != picture_structure || - last_pic_droppable != droppable) { + last_pic_droppable != droppable || + last_mb_aff_frame != mb_aff_frame) { av_log(h->avctx, AV_LOG_ERROR, "Changing field mode (%d -> %d) between slices is not allowed\n", last_pic_structure, h->picture_structure); @@ -1570,6 +1573,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264Context *h0) h->picture_structure = picture_structure; h->droppable = droppable; h->frame_num = frame_num; + h->mb_aff_frame = mb_aff_frame; h->mb_field_decoding_flag = picture_structure != PICT_FRAME; if (h0->current_slice == 0) {