thank you all very much! the closest thing (visually) to what I want to do was from Jean-Francois Charles patch "3-record-play-speed-control" with the number of frames set to 1. I just don’t know now if I have to use jit.peek to create the vertical blur like the attached image, or if there is another easier way, because i don’t see any tutorials for jit.peek..
To have a blur, I guess you would use more frames than 1, and you could use a jitter object (filter) to blur the image.
Or with 1 frame, you could use a temporal blurring, maybe something like [jit.slide].