[ttml2] Pull Request: Add #extent-length-version-2 feature (#853).

skynavga has just submitted a new pull request for https://github.com/w3c/ttml2:

== Add #extent-length-version-2 feature (#853). ==
Closes #853.

See https://github.com/w3c/ttml2/pull/854

Received on Saturday, 23 June 2018 04:53:50 UTC