@@ -2328,6 +2328,7 @@ static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
if (ret < 0)
return ret;
+ if (mkv->cluster_pos != -1) {
if (mkv->tracks[pkt->stream_index].write_dts)
cluster_time = pkt->dts - mkv->cluster_pts;
else
@@ -2355,9 +2356,10 @@ static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
start_new_cluster = 0;
}
- if (mkv->cluster_pos != -1 && start_new_cluster) {
+ if (start_new_cluster) {
mkv_end_cluster(s);
}
+ }
if (!mkv->cluster_pos)
avio_write_marker(s->pb,
In order to determine whether the current Cluster needs to be closed because of the limits on clustersize and clustertime, mkv_write_packet() would first get the size of the current Cluster by applying avio_tell() on the dynamic buffer holding the current Cluster. It did this without checking whether there is a dynamic buffer for writing Clusters open right now. In this case (which happens when writing the first packet) avio_tell() returned AVERROR(EINVAL); yet it is not good to rely on avio_tell() (or actually, avio_seek()) to handle the situation gracefully. Fixing this is easy: Only check whether a Cluster needs to be closed if a Cluster is in fact open. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> --- libavformat/matroskaenc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)