... in the extent that a non-waiting pad (so indicated by newsegment)
turns out to provide the best buffer, which is then forced to waiting
for book-keeping purposes, but that should only be temporary.
See bug #415754.
This handles muxing of sparse/subtitle streams and has
lots of cleanup. Still missing is special support for
live streams but this can be added later without breaking
API/ABI.
Based on the version from the videomixer plugin.
https://bugzilla.gnome.org/show_bug.cgi?id=415754