Tearing while playing video with mplayer on Ubuntu

I had a slight tearing problem while playing video with mplayer on my Ubuntu 8.10 machine. My machine has a Intel i945 graphics card with the i915 driver. This is how I solved it.

In my case the problem was that mplayer used wrong xvideo adaptor.

$ mplayer -v file.avi
...
using Xvideo port 97 for hw scaling

So it's using port 97.

Running xvinfo displays information about the xv xorg extension. Two adaptors in my case; one bad and one good. Mplayer is unfortunately using the bad one because it always picking number #0.

Relevant parts from xvinfo:

Adaptor #0: "Intel(R) Textured Video"
port base: 97
Adaptor #1: "Intel(R) Video Overlay"
port base: 113

Port 97 is Textured Video and port 113 is Video Overlay. The -vo parameter can be used to tell mplayer which adaptor to use.

mplayer -vo xv:port=113 file.avi

And bam! That's it.