From ab6f4bc06433c57ca9b789a5853524b67301b548 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 31 Oct 2015 21:36:00 +0100 Subject: [PATCH] avcodec/h264_slice: Disable slice threads if there are multiple access units in a packet Fixes null pointer dereference Fixes part of Ticket4977 Signed-off-by: Michael Niedermayer (cherry picked from commit 9368d2da3d33cac845f2fdf663df500b53625c5e) Conflicts: libavcodec/h264_slice.c --- libavcodec/h264_slice.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c index 968e3ecb83..10f4d77380 100644 --- a/libavcodec/h264_slice.c +++ b/libavcodec/h264_slice.c @@ -1159,6 +1159,15 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl) if (first_mb_in_slice == 0) { // FIXME better field boundary detection if (h->current_slice) { + if (h->max_contexts > 1) { + if (!h->single_decode_warning) { + av_log(h->avctx, AV_LOG_WARNING, "Cannot decode multiple access units as slice threads\n"); + h->single_decode_warning = 1; + } + h->max_contexts = 1; + return SLICE_SINGLETHREAD; + } + if (h->cur_pic_ptr && FIELD_PICTURE(h) && h->first_field) { ff_h264_field_end(h, h->slice_ctx, 1); h->current_slice = 0;