[FFmpeg-devel] [PATCH 01/20] avformat/matroskaenc: Fix ReferenceBlock timestamp

[Andreas Rheinhardt]

On Wed, Jan 1, 2020 at 1:59 AM Andreas Rheinhardt <
andreas.rheinhardt at gmail.com> wrote:

> 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 <andreas.rheinhardt at gmail.com>
> ---
>  libavformat/matroskaenc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
> index 469b604de6..9cf840c9be 100644
> --- a/libavformat/matroskaenc.c
> +++ b/libavformat/matroskaenc.c
> @@ -2167,9 +2167,9 @@ 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);
> --
> 2.20.1
>
>
Ping for the rest of this patchset.

- Andreas