How to get the NvBuffer from NvBufferGetParams

Yes, you can reference to the sample code from the link you find from the forum.

https://devtalk.nvidia.com/default/topic/966938/jetson-tx1/how-to-achieve-the-h-264-encoding-performance-4k-3-840x2-160-30fps-with-openmax-il-api-l4t-r24-1/post/4990099/#4990099