for HD video playback. i just did all these::

1. Download attached .deb files on your n900 in a directory of your choice

2. from xterm as root cd to that directory and install .deb files
dpkg -i omap3-dsp-baseimage-ti_0.i3.6-15+0m6_armel.deb omap3-dsp-libraries-ti_0.i3.6-15+0m6_armel.deb omap3-dsp-hd-codecs_0.3.8-7+0m6_armel.deb

3. from attached libgstdsp.zip copy libgstdsp.so to your n900 /usr/lib/gstreamer-0.10/libgstdsp.so

4. uninstall gstreamer0.10-openmax from n900. As root:

apt-get remove gstreamer0.10-openmax

anything else i shud do for HD recording?