filip@desktop:~$ gmplayer -prefereces- video output
MPlayer 2:0.99+1.0pre8-0ubuntu8 (C) 2000-2006 MPlayer Team
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ (Family: 15, Model: 75, Stepping: 2)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.



Unknown option on the command line: -prefereces-
Error parsing option on the command line: -prefereces-