Hi,
We support GREY format in 12_camera_v4l2_cuda. GREY is actually NV12/YU12/YV12 without UV plane. You may check how it works, and replace NvBufferColorFormat_GRAY8 with desired color format for a try.
You would need to consider data alignment in NvBuffer. Please refer to this post:
Memory for NvMap - #10 by DaneLLL