Replacing TTML parsing with imscJS library
Created by: TobbeEdgeware
This is an effort to get IMSC-1 compliant by replacing our own TTML parser with imscJS.
Both text and image profiles of IMSC-1 are supported.
The SMPTE-TT image mode is also supported for legacy image subtitle sources.
The same library is also used for parsing subtitles for Smooth Streaming.