The generic answer is: no :}
It would be a bit of a big ask of either of those apps or the varied
screensavers (xlock, xlockmore, xscreensaver, gnomes built-in
or KDEs built-in) to check for all possible others at all times. One
work-around would be (e.g. if you were using xscreensaver) to
use a wrapper-script for the player like so:
Code:
#!/bin/bash
xscreensaver-command -exit
mplayer $0
xscreensaver&
Cheers,
Tink