Wmv decoder X is an active x control that allows developers to add the ability to encode wmv files from avi to there custom software programs. Wmv decoder X encodes avi if the video is compressed however at this time the audio has to be uncompressed. Will encode to wmv v8 on windows 9x-me machines, wmv v9 on 2k-xp machines. The Windows Media 9 Format is needed for control to work. you can obtain the windows media format redistributable to add to your installer at http://wmlicense.smdisp.net/v9sdk . For win9x-me machines i will send you the wmv8 format redistributable since ms no longer offers it and the windows media 9 video format is only made for 2k xp machines. You can insert the the Active X Controls in your programs, written in a language, which supports Active X automation.