- Remove unused method in DashChunkSource.
- Remove inputEncoding parameter for subtitle parsers. We're
ignoring it in all but one of the parsers, and for the one
that does use it, it'll only ever receive null, since that's
all we're passing.
- Make TextTrackRenderer advance to the next subtitle even if
the current one hasn't finished, in the case that they overlap.
This shouldn't ever really happen, but it seems best to trust
the start time of the new sample rather than the last event
time of the previous one.
- Currently all subtitles we parse contain timestamps relative to the sample
timestamp, however we add the sample timestamp in inconsistent ways (sometimes
in the Subtitle, sometimes in the SubtitleParser). This change converges on
a single approach. It also paves the way for passing absolute offsets to use
instead, and being able to apply them in a consistent way in a single place
(PlayableSubtitle). This functionality will be required for ISO 14496-30 TTML
embedded subtitles.
Issue: #689
