gst-ffmpeg: h264: skip error concealment when SPS and slices are
 mismatching

Fixes out of array accesses

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 695af8eed642ff0104834495652d1ee784a4c14d)

Upstream-Status: Backport

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Yue Tao <yue.tao@windriver.com>
---
 libavcodec/h264.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index da144db..0aab4e7 100644
--- a/gst-libs/ext/libav/libavcodec/h264.c
+++ b/gst-libs/ext/libav/libavcodec/h264.c
@@ -2351,7 +2351,7 @@ static int field_end(H264Context *h, int in_setup)
      * past end by one (callers fault) and resync_mb_y != 0
      * causes problems for the first MB line, too.
      */
-    if (!FIELD_PICTURE)
+    if (!FIELD_PICTURE && h->current_slice && !h->sps.new)
         ff_er_frame_end(s);
 
     ff_MPV_frame_end(s);
-- 
1.7.5.4