You can play 3D movies on 2D screen by
gl:stereo=3 option, check MPlayer man page:
Select a method for stereo display. You may have to use -aspect to fix the aspect value. Add 32 to swap left and right side. Experimental, do not expect too much from it.
0 normal 2D display.
1 Convert side by side input to full-color red-cyan stereo.
2 Convert side by side input to full-color green-magenta stereo.
3 Convert side by side input to quadbuffered stereo. Only supported by very few OpenGL cards.