One of the nice features of ITS Tool is that it can merge ITS definitions from multiple sources. So when you embed TTML into Mallard, you don’t need to have a specific Mallard+TTML mode. Instead, the Mallard ITS definitions get applied, and the TTML ITS definitions get applied on top of them. I just added this ITS file to itstool git:
<its:rules xmlns:its="http://www.w3.org/2005/11/its" xmlns:tt="http://www.w3.org/ns/ttml" its:version="1.0"> <its:withinTextRule withinText="yes" selector="//tt:p//*"/> </its:rules>
This ensures that inline markup like tt:span doesn’t get split off with a placeholder into a separate translation unit. This one file applies the ITS definitions whether your TTML is embedded in Mallard, DocBook, XHTML, or any other format, or even if you have a standalone TTML file.