如何在视频播放n秒后运行特定代码

Question

I am working on python3 and using Microsoft azure face API function 'CF.face.detect' to detect faces in a video. I want to detect faces after every 1 second in the video that means run CF.face.detect once/second on video frame.

Please tell how to do it

Thanks in advance

Answer 1

If you know how many fps your video has, you could read the frames one by one and detect on every n -th frame, n being the number of fps of a video you're processing.

fps = x
cnt = 0

for f in get_frames():
  if cnt % fps == 0: 
    # run algorithm here
    cv.imwrite(f)

After you have gone through the video then you can run the algorithm. But I would suggest to run the algorithm in the loop and save the frame then, preferably with drawn result (squares for detection)