Opened 4 years ago

Last modified 4 years ago

#1305 open enhancement

Embedded ASS subtitle support

Reported by: SubJunk Owned by:
Priority: wish Component: avfilter
Version: git-master Keywords: ass
Cc: Blocked By:
Blocking: Reproduced by developer: yes
Analyzed by developer: no


It would be great to see support for embedded ASS subtitles.
Currently ASS subtitles are only supported if there is an external .ass file, but almost always it is a stream inside an MKV container (so there are 3 streams: video, audio and ASS subtitle)

It is possible currently to extract the subtitle stream from the original container, then load it in a second step, but it would be cool to be able to do it in one step instead.

For example in MEncoder you use:
mencoder input.mkv -ass -o output.mkv
And it will burn the ASS/SSA subtitles contained within input.mkv onto the video stream of output.mkv

Change History (6)

comment:1 Changed 4 years ago by SubJunk

Ah I forgot to provide a sample. It's here:
It's a 4MB direct link on my server so it won't be going anywhere :)

comment:2 Changed 4 years ago by Cigaes

  • Component changed from undetermined to avfilter
  • Status changed from new to open
  • Version changed from unspecified to git-master

That would be nice indeed, but that is hard.

Adding support for subtitles in libavfilter (and not as an external resource for a single filter) is a project, but it requires careful design, especially since, unlike video and audio streams, subtitles streams are sparse.

So yes, it will eventually be possible. But do not hold your breath yet.

comment:3 Changed 4 years ago by cehoyos

  • Keywords ass added
  • Priority changed from normal to wish
  • Reproduced by developer set

comment:4 Changed 4 years ago by SubJunk

6 months went by, is it any closer to being easier to develop this feature or is it a pipedream? :)

comment:5 Changed 4 years ago by ubitux

Unfortunately, there are a lot of subtitle issues to solve before considering this; help is needed if you are interested...

Note that you can extract the ASS track from the MKV into an external ASS (ffmpeg -i in.mkv out.ass) so you can achieve the operation anyway, it just takes two steps instead of one.

comment:6 Changed 4 years ago by SubJunk

OK, no problem. I'm happy to help in any way I can. I'm idling in #ffmpeg-devel if you want to chat there

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