I have compiled OpenCV 3.0.0 master (commit 50c9367d7ae8824654776ffd1fd6707448ccb384) with the examples. Among the examples is opencv_source_code/samples/gpu/hog.cpp, which compiles to a gpu-example-hog binary.
It runs and I see the video window with the fps. However, I am unable to get it to detect any person in the video file input (I don't see any rectangle being drawn). The original video file is 1920x1080p. I have also tried resizing it to 960x540, 640x360, 480x270, 384x216 and 320x180. None of these resolutions yielded any detection result.
Could somebody help me with tweaking the command-line arguments? I can post the original video somewhere if that helps.