Mpeg layer 1 audio codec?

does anyone know were i can find a mpeg layer 1 audio codec for WMP?

i have this xvid movie, gspot said it used layer 1, to test this i renamed the extention to .mp1, and played it with real player, but evidently WMP doest suport mp1 format and only played the video, what should i do?

where can i get mpeg- layer 1 audio codec

help to find mpeg layer 1 audio codec