Library aa (Ascii Art) should work with any video player not just mplayer it should also work with any suitable format input such as web cam or movie file format that the player itself supports. However each player syntax format will or may be different. For Example

vlc -vo caca v4l2:///dev/video0

may not be the same although it is very close to this

vlc --vout caca v4l2:///dev/video0

You can run this command below but image might appear out of sync I do not know the reason for this but to obtain an undistorted image you need to force your output to a window rather than full screen.

vlc --vout aa v4l2:///dev/video0

Do not assume all these commands use a similar format syntax it could have undesirable results

sudo apt-get install mplayer libaa1 aalib-bin caca vlc vlc-plugin*

mplayer -vo aa movie.avi