Technology – a playlist of trimmed Youtube videos

i wanted to knw if there is an app (web or otherwise)
that can “TRIM” (ie re-select the start-in point, and/or the out-end point) a youtube video.

what i want is an ability to trim( always shorten) the video clips/movies without the need to downloading it. ( i guess downloading might have copy right issues)

and making a playlist of these trimmed clips.

Simple!

now how i think IT might work is-

this simple app will result in a PLAYLIST that can viewd like a TELEVISION program, Made up of “footage from youtube” (public)

and essentially u are not changing the clip or copying it. All u need from youtube is the metadata of the clip, that is  no copy right info, right?

trimming is actually just starting to watch a 10 min clip from say 2min and stop watching it at 5mins. This is making the 10min video in a 3min video clip.
Logic of defense is u cant tell ppl to watch the entire clip or just a part of it