OpenCV using an Intel iGPU (OpenGL/OpenCL/VAAPI interop) on Linux: Custom Optical Flow Visualizatio

Performance (with this particular video): *4k: 15+FPS (20+FPS offscreen)* *1080p: 50+FPS (65+FPS offscreen)* While this visualization looks good on many videos, it was made with videos in mind that have a rather stable background (so background and foreground can be distinguished easily). Scene changes are no problem because there is explicit detection for it in place. I contacted the rights holder of the original video (BBTV) several times to ask them what they think of my fair-use of this video for educational purpose. They never answered.