VideoSpec - VideoSpec is a free AppleScript studio App (Xcode 3.
MediaInfo - MediaInfo is a convenient unified display of the most relevant technical and tag data for video and audio files
CodecInstaller - Ever had a movie where you could only hear the sound and there were no video?
GSpot - GSpot is a Windows-based freeware designed to identify codecs used in video files.
AVInaptic - AVInaptic is one of the powerful software that allows you to scan & analyze the video files from your computer and extract useful information lie duration, container, AVI index, and resolution without any disturbance.
Avicodec - AVIcodec is a free multimedia file analyser for Windows.