Need the w32codecs to play those files.

Refer to the following steps:

1.echo "deb feisty free non-free" | sudo tee -a /etc/apt/sources.list

2.wget -q -O- | sudo apt-key add - && sudo apt-get update

3.sudo apt-get install w32codecs mplayer

4.mplayer foo.wma



Problem Detail:

An error occured

The playback of this movie requires the following decoders which are not installed:

video/x-asf-unknown decoder

audio/x-asf-unknown decoder