[imsc] Specifying both tts:position and tts:origin should be forbidden

palemieux has just created a new issue for https://github.com/w3c/imsc:

== Specifying both tts:position and tts:origin should be forbidden ==
See w3c/ttml2#538

Please view or discuss this issue at https://github.com/w3c/imsc/issues/289 using your GitHub account

Received on Wednesday, 10 January 2018 20:00:20 UTC