[FFmpeg-cvslog] avcodec/cbs: fix crash in sei_pic_timestamp

[Aman Gupta]

ffmpeg | branch: release/4.0 | Aman Gupta <aman at tmm1.net> | Thu Oct 11 20:42:58 2018 -0700| [70d0d83d4d61f4c85ff4fe75e24de94a27f61288] | committer: Aman Gupta

avcodec/cbs: fix crash in sei_pic_timestamp

Signed-off-by: Aman Gupta <aman at tmm1.net>
(cherry picked from commit b6c3a02740871f4992ab7c34a95dfa53a56ba382)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=70d0d83d4d61f4c85ff4fe75e24de94a27f61288
---

 libavcodec/cbs_h264_syntax_template.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/cbs_h264_syntax_template.c b/libavcodec/cbs_h264_syntax_template.c
index b5cd0b2310..834b44a091 100644
--- a/libavcodec/cbs_h264_syntax_template.c
+++ b/libavcodec/cbs_h264_syntax_template.c
@@ -539,6 +539,12 @@ static int FUNC(sei_pic_timestamp)(CodedBitstreamContext *ctx, RWContext *rw,
     }
 
     sps = h264->active_sps;
+    if (!sps) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR,
+               "No active SPS for pic_timestamp.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
     if (sps->vui.nal_hrd_parameters_present_flag)
         time_offset_length = sps->vui.nal_hrd_parameters.time_offset_length;
     else if (sps->vui.vcl_hrd_parameters_present_flag)