[FFmpeg-trac] #2402(FFmpeg:open): FFmpeg marks no subtitles in mkv files as default

[FFmpeg]

#2402: FFmpeg marks no subtitles in mkv files as default
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             Reporter:  someuser     |                    Owner:
                 Type:  enhancement  |                   Status:  open
             Priority:  wish         |                Component:  FFmpeg
              Version:  git-master   |               Resolution:
             Keywords:  mkv          |               Blocked By:
             Blocking:               |  Reproduced by developer:  1
Analyzed by developer:  1            |
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Comment (by someuser):

 Replying to [comment:1 cehoyos]:
 > None of your input subtitle streams is marked as default, current FFmpeg
 therefore does not write the default flag for any of the subtitle tracks.
 The Matroska specification -
 http://matroska.org/technical/specs/index.html (search for FlagDefault) -
 specifies that the value for the default flag is "default" if nothing is
 specified, the demuxer therefore marks all subtitle tracks as "default".

 Ok, thanks for this background information, I was looking at the above
 output and saw '''DISPOSITION:default=1''' and also in ''ffmpeg -i
 test.mkv'' output there is:

 {{{
 Stream #0:2(eng): Subtitle: subrip (default)
 Stream #0:3(fra): Subtitle: subrip (default)
 }}}

 > What is missing afaict is a possibility for the user to mark streams as
 default streams, an alternative is to always set the first stream as
 default in the Matroska muxer, I am not completely convinced that this is
 the best solution,

 For me as a user the ability to mark streams as default streams sounds
 like an ideal solution, although forcing the first one being the default
 one would be ok'ish, too.

 > consider sending a patch if that is what you want.

 I am a user unfortunately not a developer so I tried to do my best with
 home work wrt googling, reading documents, checking for duplicate tickets,
 etc and since I couldn't find any clear answers I wanted to file this
 ticket to serve as a note for other users and developers alike.

 Thanks.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2402#comment:3>
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