CodecViewer is small program that tells you what audio and video codec you need for an avi file. If you want to watch a movie or to listen to a special type of music file and don't know which codec you need to be able to do this, then CodecViewer is the tool you need. Program says "Unknown" codec ? Seems as if you are using a codec, which is not supported by M$, and I don't know... If you got any clue what codec it is, and what it's FOURCC is ( or can send me the file ), I will include it in future versions. [ read more about CodecViewer >> ]