Hi,
NvBufSurface APIs are more flexible, so we would suggest use the interface. You can start from the samples:
/usr/src/jetson_multimedia_api/samples
The function calls of getting GPU pointer is demonstrated in cuda_postprocess() in
/usr/src/jetson_multimedia_api/samples/12_v4l2_camera_cuda
If you prefer using nvivafilter plugin, please try to build this sample and give it a try:
Nvcompositor plugs alpha is not work and alpha plugs no work - #14 by DaneLLL