From 8b2e5e42bb9d6a59ede5af2e6df4aaf7750d1195 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Thu, 28 Nov 2013 10:54:35 +0100
Subject: [PATCH] h264: check that an IDR NAL only contains I slices

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
---
 libavcodec/h264.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 6f329aacb3..4b10a68f03 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -3383,6 +3383,12 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
     h->slice_type     = slice_type;
     h->slice_type_nos = slice_type & 3;
 
+    if (h->nal_unit_type  == NAL_IDR_SLICE &&
+        h->slice_type_nos != AV_PICTURE_TYPE_I) {
+        av_log(h->avctx, AV_LOG_ERROR, "A non-intra slice in an IDR NAL unit.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
     // to make a few old functions happy, it's wrong though
     h->pict_type = h->slice_type;