Ubuntu – Command line flag for mplayer to use hardware acceleration

Why not just put a list of the video outputs and codecs you want to try in your ~/.mplayer/config file? As in:

##################
# video settings #
##################

# Specify default video driver (see -vo help for a list).
vo=vdpau


############
# Profiles #
############

# The options declared as part of profiles override global default settings,
# but only take effect when the profile is active.

[vo.vdpau]
vc=ffmpeg12vdpau,ffwmv3vdpau,ffvc1vdpau,ffh264vdpau,ffodivxvdpau,
# Most video filters do not work with vdpau.
vf-clr=yes

¹ the trailing comma in each setting tells mplayer to fall back to standard codecs if necessary

Create a named pipe like this:

mkfifo ~/.mplayer/pipe

Then, put the following line in ~/.mplayer/config:

input=file=/home/<username>/.mplayer/pipe

or you can run mplayer with input argument:

mplayer -input file=/home/<username>/.mplayer/pipe

Now use System Setting->Keyboard->Shortcut and add a shortcut with the command parameter as (see mplayer -input cmdlist for the command list):

echo "<mplayer command>" > /home/<username>/.mplayer/pipe

e.g. echo "pt_step 1" > /home/<username>/.mplayer/pipe for next track.

and then assign a key to this shortcut.