Use the gst_video_aggregator_pad_has_current_buffer API
to check if the current sinkpad has a queued buffer before
attempting to obtain a input buffer from the base plugin.
If the sinkpad does not have a current buffer, then it is
either not producing them yet (e.g. current time < sinkpad
start time) or it has reached EOS.
Previously, we only handled EOS case.
Example:
gst-launch-1.0 videotestsrc num-buffers=100 \
! vaapipostproc ! vaapioverlay name=overlay \
! vaapisink videotestsrc timestamp-offset=1000000000 \
num-buffers=100 ! video/x-raw,width=160,height=120 \
! overlay.
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.
