[FFmpeg-user] MPEG-DASH video with Subtitles

[Nate]

Hello,



I am trying to take a video with subtitles, run it through ffmpeg with the “dash” output format and get ffmpeg to output the subtitles.



Steps that I’ve taken:



1.       I took this video: https://www.youtube.com/watch?v=QF8pM4wiLaY and downloaded the mp4 and srt files

2.       I combined them with this command:

bin\ffmpeg.exe -i "Prime Minister's Questions_ 25 March 2015\Prime Minister's Questions_ 25 March 2015 (480p).mp4" -sub_charenc UTF-8 -i "Prime Minister's Questions_ 25 March 2015\Prime Minister's Questions_ 25 March 2015 (480p).English.srt" -vcodec copy -acodec copy -scodec mov_text -metadata:s:s:0 lang=eng "Prime Minister's Questions_ 25 March 2015.mp4"

3.       I then tried to dash the video with this command:

bin\ffmpeg.exe -i "Prime Minister's Questions_ 25 March 2015.mp4" -vcodec copy -acodec copy -scodec copy -f dash out.mpd
ffmpeg finds the subtitle track in the video:

    Stream #0:0(und): Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 854x480 [SAR 1:1 DAR 427:240], q=2-31, 659 kb/s, 25 fps, 25 tbr, 12800 tbn, 25 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, 253 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
    Stream #0:2(und): Subtitle: mov_text ([8][0][0][0] / 0x0008), 0 kb/s (default)
    Metadata:
      handler_name    : SubtitleHandler

But the subtitles do not appear as a track in the resulting out.mpd file or segment files.
I tried using the –adaptation_sets option to force it but it didn’t seem to do anything.

Are subtitles supported in the “dash” output format?  Am I doing something wrong?

Thanks,
Nate