I've been watching videos using mpv, a derivative of MPlayer, using the default options. When I increase the speed, pitch-shift kicks in so that while people sound like they're speaking faster, they aren't squeaky and hard to understand like they're on helium.
The pitch-shift (in the manual as scaletempo) works fairly well, but I've noticed that YouTube does it significantly better.
How does YouTube shift pitch, and is there any way I can improve MPlayer's pitch shift (by tweaking the scaletempo options, f.e.)?