[MPlayer-users] How to keep video from centering on screen?

[Sage]

Every time a new video stream starts up in mplayer, the video window
centers itself on the screen. This wouldn't be so bad except that I use
dual monitors and Xinerama (actually, I use the nVidia drivers with
Twinview, but the result is the same) and the video is centered between
the two screens, with half the video on one screen and half the video on
the other. I would greatly prefer the video window to remain wherever I
move it to on the screen. Is there a setting in mplayer that enables
this? I have been unable to find it in the program or the documentation.