I just tried the canola-mplayer plugin. I must admit, it is difficult
to find information on how to enable it, when in fact it is very
simple to install:

-1- in application manager, edit the canola repository and add
experimental
-2- canola-mplayer should now show up in the list of installable
applications
-3- enable the plugin via the canola config web interface

A few comments on the plugin, and feature requests:

* I have got the latest mplayer from
https://garage.maemo.org/projects/mplayer/ - it is not clear
whether canola uses this one, or the older compile from the canola
repository

* it works very well: at last I can use canola to watch videos;
the built in media player was useless to me

* pause does not work :-( That's a big problem for me. I suspect
this is due to canola launching mplayer in slave mode, but as
it is not able to control it, mplayer does not register the
pause event; please enable pause mode

* osd does not show (eg: volume control, fast forward, ...).
This is very annoying and again probably caused by launching
mplayer with a parameter to disable the osd

* the non full screen mode does not integrate with canola; I
am aware this is an experimental plugin, so that's kind of expected.
I think you might be able to do it by using the -noborder and
size parameters

* mplayer can play many more filetypes than the built in media
player, so I suggest when the mplayer plugin is enabled you scan
for more filetypes (eg: mkv, ogm, mp4). The only way I managed
to get my videos recognised was by renaming then from *.mkv to
*.avi (which is misleading, but mplayer recognizes they are matroska
containers)