04/24/05

  Microsoft MPEG-4 

Ancestor of current Microsoft Windows Media codec, MPEG-4 v2 can encode AVI. Renamed Windows Media 7, MPEG-4 v3 is not an AVI codec. Still widely used despite being obsolete from a technical standpoint, MPEG-4 v2 encodes AVIs which are more convenient than Windows Media files. More than adequate for most video sources, MPEG4 v2 differences are rather subtle while subsequent Windows Media codecs do give better quality. At very low bit rates (500 kbps), blockiness becomes very noticeable. Usually quite small, MPEG4 video files are among the smallest of all delivery codecs. Available as a free download from Microsoft, MPEG4 is compatible with Windows 2000 and XP. With only three parameters to adjust, the codec provides adequate control. Using the default settings, most videos are acceptable in terms of quality. Unable to specify an average rate, Encoding is rather fast at maximum data rate. Although larger than need be, file size can be hard to estimate. Launching MPEG-4 before the standard was in agreement, Microsoft changes the MPEG-4 codec name to Windows Media in later versions. If the codec is non MPEG-4 compliant, the MPEG4 standard does not matter for downloading and web distribution. However, requiring a compliant MPEG4 codec to compress video files, Microsoft Windows Media is the wrong codec.

http://graphics.csail.mit.edu/~tbuehler/video/codecs/avi.html