Using the properties – playing a video backwards

To see how we can use the aforementioned properties, we are going to understand the read_video_file_backwards.py script, which uses some of these properties to load a video and output it backwards, showing the last frame of the video first and so on. We are going to use the following properties:

• cv2.CAP_PROP_FRAME_COUNT: This property provides the total number of frames
• cv2.CAP_PROP_POS_FRAMES: This property provides the current frame

The first step is to get the index of the last frame:

# We get the index of the last frame of the video file
frame_index = capture.get(cv2.CAP_PROP_FRAME_COUNT) - 1

Therefore, we set the current frame to read to this position:

 # We set the current frame position
 capture.set(cv2.CAP_PROP_POS_FRAMES, frame_index)

This way, we can read this frame as usual:

 # Capture frame-by-frame from the video file
 ret, frame = capture.read()

Finally, we decrement the index in order to read the next frame from the video file:

 # Decrement the index to read next frame
 frame_index = frame_index - 1

The full code is provided in the read_video_file_backwards.py script. This script can be easily modified to save the resulting video playing backwards (not only showing it). This script is proposed in the Question section.