Recursive functions are elegant but dangerous since they might
overflow the stack. It is better to turn them into a list tranversal
if possible, as this case.
Instead of using a parent structure that has to be derived by API
consumers, this change propse a simplification by using the common
pattern of GTK of passing a function pointer and user data which will
be passed as its parameter. That user data contains the state and the
function will be called to update that state.
A plugin similar to the base compositor element but
uses VA-API VPP blend functions to accelerate the
overlay/compositing.
Simple example:
gst-launch-1.0 -vf videotestsrc ! vaapipostproc \
! tee name=testsrc ! queue \
! vaapioverlay sink_1::xpos=300 sink_1::alpha=0.75 \
name=overlay ! vaapisink testsrc. ! queue ! overlay.
