How to use video_codec_sdk for linux?

hello , I am trying to decode RTSP stream with the help of Ffmpeg based on GPU.
And the operation system is ubuntu. I have downloaded the SDK and found the description for the NvDecodeD3D9 is quiet few.
Any blogs or suggestion about this would be appreciated!

decode rtsp stream with ffmpeg on Titan X,Ubuntu16.04

Please refer to our decoder programming guide for more details about how to use NVDECODEAPI to program the decoder. Let us know if there is anything specific that is not clear.

Ryan Park