netbsdnoob As you've introduced me to Vulfpeck, I'll try to help you.
Download the video using youtube-dl, then play it locally using mpv. Press I. How many frames are dropped?
Using my lowest CPU frequency, 800 MHz, playing Dean Town, I see 7 output frames dropped at the end of the video with vo=sdl, and 425 dropped output frames with vo=xv (the default), but, no noticeable slowdowns in either case.
