From 6a1bf8634acdd7112979b7e5ae6684e4acaf3339 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Wed, 1 Jan 2020 01:58:18 +0100 Subject: [PATCH] avformat/matroskaenc: Fix ReferenceBlock timestamp In order to indicate that the frames in a BlockGroup are not keyframes, one has to add a ReferenceBlock element containing the timestamp of a referenced Block that has already been written. The timestamp ought to be relative to the timestamp of the Block it is attached to. Yet the Matroska muxer used the relative timestamp of the preceding Block of the track, i.e. the timestamp of the preceding block relative to the timestamp of the Cluster containing said block (that need not be the Cluster containing the current Block). This has been fixed. Signed-off-by: Andreas Rheinhardt Reviewed-by: Paul B Mahol Signed-off-by: James Almer --- libavformat/matroskaenc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index 71c9afb15c..953421435d 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -2163,9 +2163,9 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb, av_free(data); if (blockid == MATROSKA_ID_BLOCK && !keyframe) { - put_ebml_sint(pb, MATROSKA_ID_BLOCKREFERENCE, track->last_timestamp); + put_ebml_sint(pb, MATROSKA_ID_BLOCKREFERENCE, track->last_timestamp - ts); } - track->last_timestamp = ts - mkv->cluster_pts; + track->last_timestamp = ts; if (discard_padding) { put_ebml_sint(pb, MATROSKA_ID_DISCARDPADDING, discard_padding);