Video looping and repeat

aloha !

i want to find an option of automatic blending mode from a live frame.
after X time, the last scene will be in an opacity of (lets say) 80 precent, while the new scene on top will be in higher opacity. im trying to make a collages of scenes in order to create a chaotic image (lorenzo attractor) from the same object recorded which moves slowly all the time. same frame (after x time) will reduce its opacity every X time in order to blend with the new scenes in higher opacity.