Support setting the title/text background color with transparency
@jeff
Submitted by Jeff F.T. Assigned to Thibault Saunier @thiblahute
Description
We were missing something in GES/gstreamer to set the background color of titlesource in order to use exclusively this element for our title editor.
However, there now is
ges_timeline_title_source_set_background ()
...in the api docs in GES. In theory, this "should" work now that we have video compositing/mixing in GES.
Once this is done, the title editor/timeline codebase in Pitivi should be updated to get rid of the silly "titles as overlays as properties of a video clip" approach, and only keep the "each title is a clip by itself" approach. See http://wiki.pitivi.org/wiki/Title_editor_design for an explanation of that.
Imported from https://bugzilla.gnome.org/show_bug.cgi?id=708411