Are u using xvesa flavor?

Mplayer does not even play video on my slitaz 3 xvesa, only the audio of a video.

Xine-ui scales the video with the window unless you change the settings not to do that.

no using simple default release (slitaz stable 3.0) .
It plays both audio and video but I am unable to change the size of video only the windowframe resizes ( intel 845g graphic controller, 256MB ram , celron1.7)
the mplayer also gives an error every time when it starts
Error:
No accelerated color space conversion found for yuv420p to bgra



waiting for help

Open terminal
type

mplayer -zoom /path/to/video.file.avi

enter
F key toggles fullscreen
If this works make a file called config in .mplayer directory add
zoom="1"
Then it will work with the gui or without adding -zoom switch in terminal

thanks...........I used zoom='2' in mplayer.conf and now i can resize mplayer in gui

Now your thinking outside the box ;)