Most of you face to problem to download Codec to play Video or Audio in your operating system. As I know Microsoft Windows Operating systems are not too much, but Linux OS users facing this. so tool is MediaInfo (http://sourceforge.net/projects/mediainfo/). it is OpenSource and supports Linux and Microsoft Windows Operating Systems. It gives to links to download Codec or Media player support that codec.
Hint: when you use Microsoft Windows Operating systems ffdshow tryouts (http://ffdshow-tryout.sourceforge.net) and it includes all codec to play any video.
