• Chris Bass's avatar
    ttml: Add support for IMSC 1.0.1 fillLineGap attribute · 2863a55a
    Chris Bass authored
    Strictly speaking, the TTML spec requires that text backgrounds extend
    only to the font height of the related text, rather than to the vertical
    distance between lines. The result of this is that there will typically
    be vertical gaps between line backgrounds through which moving video can
    be seen. Since this was unnacceptable to some content providers, v1.0.1
    of the IMSC spec (which profiles TTML) adds a new attribute,
    itts:fillLineGap[1], that allows content authors to specify that clients
    should extend text backgrounds such that there are no gaps between
    lines. This attribute is also going to be included in the next release
    of EBU-TT-D.
    This patch adds support for fillLineGap to ttmlparse and ttmlrender.
    [1] https://www.w3.org/TR/ttml-imsc1.0.1/#itts-fillLineGap
ttmlparse.c 58.9 KB