Wikipedia
MediaInfo is a free and open-source program that displays technical information about media files, as well as tag information for many audio and video files. It is used in many programs such as XMedia Recode, MediaCoder, eMule, and K-Lite Codec Pack. It can be easily integrated into any program using a supplied MediaInfo.dll. MediaInfo supports popular video formats (e.g. AVI, WMV, QuickTime, Real, DivX, XviD) as well as lesser known or emerging formats such as MKV including WebM. In 2012 MediaInfo 0.7.57 was also distributed in the PortableApps format.
MediaInfo provides a command-line interface for displaying the provided information on all supported platforms. Additionally, a GUI for viewing the information on Microsoft Windows and Mac OS X is provided. Users that want to have the Windows GUI version of the software can choose to download it bundled with the OpenCandy installer to support the software's creators.