[PROPOSAL] Add support for TTML EBU-TT-D and IMSC1 profiles.

[donmartin00]

CCExtractor Version: 0.88

Necessary information

• Is this a regression (i.e. did it work before)? {NO}
• What platform did you use? {Window}
• What were the used arguments? {No arguments - we did not notice any options for TTML EBU-TT-D or IMSC1. We would like to have these types of files recognized through this program.}

[bbgdzxng1]

Adding a link to the EBU-TT Toolkit in case a commercial sponsor is identified. "The kit is envisaged to contain a set of components for generating, testing and distributing subtitle documents in EBU-TT Part 3 format". It useful to have a test suite if and when the time comes - it looks like EBU-TT Team have put together an extensive test suite.

https://github.com/ebu/ebu-tt-live-toolkit
http://ebu.github.io/ebu-tt-live-toolkit/html/index.html

And for IMSC1...
https://github.com/w3c/imsc-tests
https://github.com/w3c/imsc/

For any passers-by seeing OP's feature request, here's a useful intersection and overlap of the various TTML profiles and where EBU-TT fits in.