[FFmpeg-devel] [PATCH 12/20] avformat/matroskaenc: Improve Cues in case of no video

[Jan Chren (rindeal)]

On Sun, 5 Apr 2020 at 16:01, Andreas Rheinhardt
<andreas.rheinhardt at gmail.com> wrote:
>
> The Matroska muxer currently only adds CuePoints in three cases:
> a) For video keyframes. b) For the first audio frame in a new Cluster if
> in DASH-mode. c) For subtitles. This means that ordinary Matroska audio
> files won't have any Cues which impedes seeking.
>
> This commit changes this. For every track in a file without video track
> it is checked and tracked whether a Cue entry has already been added
> for said track for the current Cluster. This is used to add a Cue entry
> for each first packet of each track in each Cluster.
>
> Implements #3149.
>
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---

Fixed at last, danke schön! This was a very annoying bug.

One thing I noticed is, however, that the spec recommends "CuePoint
Elements SHOULD reference audio keyframes at most once every 500
milliseconds" [1], but this is not checked currently.

[1]: https://cellar-wg.github.io/matroska-specification/cues.html