[PROPOSAL] Validate TTML subtitles in an MPEG2-TS

[donmartin00]

CCExtractor Version: 0.88

Necessary information

• Is this a regression (i.e. did it work before)? {NO}
• What platform did you use? {Window/Mac}
• What were the used arguments? {The first time testing our TTML in MPEG2-TS to validate the subtitles we used the windows gui, and the autodetect radio button; no subtitles were found. The second time we attempted to use the command line and tried all the different input files with our TTML in MPEG2-TS and again no subtitles were found or generated.}

Additional information

1. We would like to have a feature to validate TTML subtitles in an MPEG2-TS per specification https://www.etsi.org/deliver/etsi_en/303500_303599/303560/01.01.01_60/en_303560v010101p.pdf