Changed code into c++, and now window shows the difference between current frame and last frame.
able to trigger a sentence, but the frame rate of the program drops.
fixed frame drop.
enhanced frame subtraction.
- added rtmidi, able to send midi signals through virtual ports.
- the red box bugs.
flipped image.
Progress

-background subtraction for motion detect
-uparrow to update background
-trigger to send midi signal to device0
-fps drop was at the minimal