CodecInstaller: free program for installing A/V codecs
Of course, if you've got a good media player like VLC or ZoomPlayer, you probably don't need a separate program to install these codecs. But CodecInstaller can still come in handy if you want a lightweight program for analyzing audio and video files.
Just click the analyze button at point CodecInstaller at your mystery file. It's not perfect. For example, when we tried to analyze several DivX recordings made using BeyondTV, it could only find info for the audio codec, not the video codec. But if you want to know the bitrate, framerate, codec, or dimensions of that file you downloaded from the interwebs, you might want to give CodecInstaller a try.