Hi,
If you need CUDA filters in OpenCV. The data is in cv::gpu::gpuMat, which can be directly accessed through CUDA. The performance is optimal.
If you need OpenCV functions that data is in cv::Mat, it may take certain CPU usage in converting frame data into BGR format, and the functions consume CPU also.
For demo of using CUDA filters, please take a look at
LibArgus EGLStream to nvivafilter - #14 by DaneLLL