Playing video on beagleboard Ubuntu

I have installed Ubuntu successfully on devkit8000, thanks to the
wonderful help from Robert Nelson's website and himself.

There is no problem playing audio. However, when it comes to playing
video (using gstreamer), the frame rate looks very slow. The
resolution does not look sharp either.

Does anyone know how to improve on the video quality on Ubuntu running
on OMAP? Is there any helpful websites I can visit? I think the DSP on
the OMAP3530 is not being utilized. Does someone know how to enable
the OMAP DSP while playing video?

Thank you.

did you set necessary variables in u-boot to enable DSP?