Video player questions

I have my B7 Beagle running Anstrom with 2.6.28 kernel. I am trying
to configure for best video playback. Questions are:
1. For mplayer, does resolution in bootargs "video=omapfb:mode:
1280X720@50 init =/init" need to agree with video format? When I play
big buck bunny 720p mp4, it runs slow.

2. for omapfplay, how do I configure kernel video mode boot args? I
see no reference to "mode" but to "vram:2M:vram4M" What is difference
between vram parameters and mode parameters as in above? Also need a
pointer to omapfbplay instructions and playback options/switches. (I
can't get it to run.)

3. Trying to get my USB camera to display on the dvi-d screen
(Angstrom running). Is it best to use Mplayer to display USB video?
So far no luck seeing the actual video although I see evidence the
camera is producing a video stream.

4. Not strictly a video question, but I when I run the linux command
"top" while running the Elightenment desktop, I see memory is in short
supply, 22Meg free, when I start firefox browser, memory is down to
only one or two Meg free, anything I can do to alleviate the memory

Thanks very much.