MPEG-DASH: Live profile stream with TTML subtitles not played
When an MPEG-DASH stream (live profile) contains subtitles, the playback of the stream starts, but neither video nor audio are played. The media information window shows the containted streams (except the subtitles).
I tested the following streams:
- http://irtdashreference-i.akamaihd.net/dash/live/901161/bfs/manifestARD.mpd
- http://irtdashreference-i.akamaihd.net/dash/live/901161/keepixo1/manifestBR2.mpd
- https://vm2.dashif.org/livesim/testpic_2s/multi_subs.mpd
The following streams work in constrast:
- VoD profile stream with subtitles: https://vm2.dashif.org/dash/vod/testpic_2s/multi_subs.mpd
- live profile stream without subtitles: https://vm2.dashif.org/livesim/testpic_2s/Manifest.mpd
This is not about support for rendering TTML subtitles from MPEG-DASH itself - I will open a separate ticket for this. This is just about the playback not starting.
Note that the two IRT streams are available worldwide and always consist of subtitles; I assume that this also applies to the DASH-IF streams.