- Can we detect motion from a video file instead of from a camera? How is this achieved?
Yes, we can. Just use the video file path to construct the VideoCapture instance. More details can be found at https://docs.opencv.org/4.0.0/d8/dfe/classcv_1_1VideoCapture.html.
- Can we perform the motion detection work in a thread that differs from the video capturing thread? If so, how is this possible?
Yes. But we should use a number of synchronization mechanisms to ensure data safety. Also, if we dispatch the frames to different threads, we must ensure that the order of the resulting frames is also correct when they are sent back and are about to be shown.
- IFTTT allows you to include images in the notifications it sends—How could we send an image with the motion we detected while sending notifications to your mobile phone via this feature...