[ttml2] Pull Request: Make begin times relative to the document temporal coordinate space (#512)

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

== Make begin times relative to the document temporal coordinate space (#512) ==
Closes #512. Resolves the ambiguity of whether the root temporal extent begins at the same time as the document's temporal coordinate space.

Clarifies that body element and isd:isd begin and end times are relative to that coordinate space, rather than the root temporal extent, whose begin time is not necessarily the origin of the document's temporal coordinate space.

See https://github.com/w3c/ttml2/pull/616

Received on Wednesday, 31 January 2018 16:52:02 UTC