There must have been an occasion when you launched a video and got sound but no picture. The most likely cause is that you never had the correct codec installed, so here’s how to find out exactly which codec is needed to play any media file.
Finding the Codec
Head over to the developer’s website and grab a copy of CodecInstaller (full package).
Once downloaded, launch it and run through the install wizard.
Once you have it installed, launch it from the shortcut on your desktop, then click on the analyze file button.
Now you will need to select a file, once selected, you will be given a fairly detailed break down of the file. It looks like the file I chose is encoded with the FLAC codec.
A quick Google search takes us directly to the download page where i can grab a copy of the FLAC codec.
Of course you could always use VLC, but for those more conscious about what gets installed on their PC’s, this is a great alternative.