TTML: Support linePadding attribute

Open

#7,521 opened on Jun 18, 2020 0 comments 1 reaction 1 assignee Claimed by @icbaker View on GitHub

enhancement

Description

IMSC spec: https://www.w3.org/TR/ttml-imsc1.1/#text-linePadding

Mentioned here in https://github.com/google/ExoPlayer/issues/7516#issuecomment-645886878.

This issue has not been assessed yet.