Support non-transcript insertions #279
Description
During the TTWG call of 2025-01-16 @gkatsev described a "dubtitling" experience in which a viewer watching content with original language audio and translation subtitles generated from the dubbing translation would experience poorly synchronised subtitle presentation, including in some cases insertion of words not present in the original transcript at all. The example genre discussed was animé.
Consider adding an explanation of how non-transcript insertions can be modelled in the DAPT Script.
For example, what value should the daptm:represents have for an inserted Script Event?