We have been designing and implementing scalable streaming servers for the past several years [4, 5]. Initially we did most of our system testing with either MPEG-1 or MPEG-2 streams. When the DivX codec became available we were interested to try MPEG-4 streaming at lower bitrates that would be suitable for ADSL or Cable modem connections. At first, version 3 of the DivX codec was only available in binary code form for the Windows platform. However, we had already implemented a Linux MPEG-2 client and wanted to re-use as much as possible of that software.

While investigating possible solutions we discovered a project called avifile for Linux (avifile.sourceforge.net). Its goal was to provide a runtime environment on Linux that would allow the execution of Windows codecs which are generally provided as Dynamic Link Libraries (DLL). To that end, it uses a specific subset of the libraries from the Wine project (www.winehq.com). Wine is an implementation of the Windows 3.x and Win32 application programming interface on top of X11 and Unix. Because Windows codecs have a very narrow and well-defined interface, only a small subset of theWine code—a library to provide a runtime environment for DLLs — is necessary to successfully executeWindows codecs.