Hi,
The code are open source and we encourage users to do customization. For using appsrc, you may refer to
https://devtalk.nvidia.com/default/topic/1026106/jetson-tx1/usage-of-nvbuffer-apis/post/5219225/#5219225
It has to use CPU buffers in appsrc, so for Z16->I420 conversion, it may not be possible to do it on GPU(through CUDA). You can implement it on CPU first and check if the performance is acceptable.