Gpudirect for video

Hello everyone,
According to this link

https://www.google.com/url?sa=t&source=web&rct=j&url=http://developer.download.nvidia.com/devzone/devcenter/cuda/docs/GPUDirect_Technology_Overview.pdf&ved=0ahUKEwjLi8LMl_nKAhVC32MKHavRDfkQFggaMAA&usg=AFQjCNG1hZR2S3NmGnx1fADB_OCFE5MpAw&sig2=Y6wvk2VR0Qqxv4pIXYn11Q

You can use gpu direct for video in cuda directx or opengl but I can’t find any documentation on any of those 3 except for one example in opengl that my sdi card manufacturer decklink provides in there sdk

Does anyone know anymore information or where I can get any more information?

Thanks