mplayer problem

so, I tried to use -vo option for every devices from `mplayer -vo help`. It helps to playing sound, but noone device can display graphics. I was trying to use -vf spp,scale together with -vo options. This method did't help too. I should tell you that now I have some other information from mplayer:

Linux RTC init error in ioctl (rtcirqpset 1024): Permission denied startup scripts.

but I really doubt that help me and I don't know about what startup scripts is going about ( I am really newbie ) .

Moreover, I must say that I tried to execute "startx -- -depth 24" or "startx -- -bpp 24", but ubuntu displays:

xauth: creating new authority fileroot-.serverauth.5427

bane server error: Server is already active for display 0 If this server is no longer running, removetmp-.X0-lock and start again.

( I had to change my profile to root. )

I think that this command "startx -- -depth 24" or "startx -- -bpp 24" should be added to some init scripts but I really don't know to which one. Additionally, I don't know how can I find out what bitdepth is my display.

btw. I use ubuntu dapper ( this information can be found out from second post ). please be lenient for me:)