I recently wrote a script such that I could easily playback files easily in mythtv. It just finds out which codec the file in question is using, and launches mplayer with the correct codec. Nothing much, but I thought someone might find it useful. Just change the $mplayerlocation to wherever it is on your computer and uncomment the last if fi statement to enable vc-1.

Code:
#!/bin/bash
#Script to automatically find out which codec a file is using and determine whether or not to use VDPAU.

#if no input display usage
if [ -z "$1" ]; then
	echo usage: $0 /path/to/file
	exit
fi

#remember to change this to the path of your mplayer binary
mplayerlocation=/usr/local/bin/mplayer-vdpau-3263604/mplayer-vdpau
cd $mplayerlocation

#kinda a lame way to do it, but bring up mplayer and pipe the output to a temporary file, then read which codec the file is
./mplayer -identify -vo vdpau $1 > /tmp/VIDEOCODEC &
sleep 0.5
killall mplayer
videocodec=`cat /tmp/VIDEOCODEC | grep ID_VIDEO_CODEC | cut -c 16-25`
rm /tmp/VIDEOCODEC

echo "VIDEO CODEC: $videocodec"

if [ $videocodec = "ffh264" ]; then
	codec='h264'
	echo \n Playing $1 with $codec codec \n
	./mplayer -vo vdpau -vc ffh264vdpau $1

	exit
fi

if [ $videocodec = "ffmpeg2" ]; then
	codec='MPEG2'
	echo \n Playing $1 with $codec codec \n
	./mplayer -vo vdpau -vc ffmpeg12vdpau $1

	exit
fi

if [ $videocodec = "ffwmv3" ]; then
	codec='WMV3'
	echo \n Playing $1 with $codec codec \n
	./mplayer -vo vdpau -vc ffwmv3vdpau $1

	exit
fi

#VC1 is not supported on most gpus
#uncomment if it is supported on your gpu
#if [ $videocodec = "ffvc1" ]; then
#	codec='VC1'
#	echo \n Playing $1 with $codec codec \n
#	./mplayer -vo vdpau -vc ffvc1vdpau $1
#
#	exit
#fi

#if it isnt one of those it is not supported by vdpau
#so we should play without vdpau
./mplayer $1
exit