What is it :

omxplayer is a commandline OMX player for the Rasipberry PI.

It was developed as a testbed for the XBMC Raspberry PI implementation
and is quite handy to use standalone. 

Using it :

Usage: omxplayer [OPTIONS] [FILE]
Options :
         -h / --help                    print this help
         -a / --alang language          audio language        : e.g. ger
         -n / --aidx  index             audio stream index    : e.g. 1
         -o / --adev  device            audio out device      : e.g. hdmi/local
         -i / --info                    dump stream format and exit
         -s / --stats                   pts and buffer stats
         -p / --passthrough             audio passthrough
         -d / --deinterlace             deinterlacing
         -w / --hw                      hw audio decoding
         -3 / --3d                      switch tv into 3d mode
         -y / --hdmiclocksync           adjust display refresh rate to match video
         -t / --sid index               show subtitle with index

For example: ./omxplayer -p -o hdmi test.mkv

Compiling :

You need the content of your sdcard somewhere mounted or copied.
There might be development headers to install on the running PI system
for the crosscompiling.

Edit Makefile.include and change the settings according your locations.

You can also compile it on the PI the native way ;)

Run : 

  make ffmpeg
  make
  make dist

Installing :
  copy over omxplayer-dist/* to the PI /