I don't think it is possible to protect files that are in .wmv formats. Even you are playing the file using a media player plugin. The source code will still be a able to figure it out. The other was changing the .wmv to other formats. Or even live streaming through the server. Another was importing the song to a flash-based, a .swf file. If not you would want to try converting the html codes to javascripts. There is a topic below this. Hiding Source Codes.