[FFmpeg-devel] [PATCH] lavf/matroskaenc: fix crash on empty H.264 packets

[Rodger Combs]

Fixes:
ffmpeg -i https://dl.dropboxusercontent.com/u/105828/sample%20crash%20file.mkv \
-bsf:v h264_mp4toannexb -c copy -y -f matroska /dev/null

Not 100% sure if this is the best place to do this.
---
 libavformat/matroskaenc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 3b525ad..37d9caa 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -1568,7 +1568,8 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb,
            avio_tell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration,
            keyframe != 0);
     if (codec->codec_id == AV_CODEC_ID_H264 && codec->extradata_size > 0 &&
-        (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
+        (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1) &&
+        pkt->data)
         ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
     else if (codec->codec_id == AV_CODEC_ID_HEVC && codec->extradata_size > 6 &&
              (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
-- 
2.4.1