VirtualDub is an extremely efficient video capture and processing program. Applications of it are almost unlimited. You can use it to for example compress an MJPEG AVI file to MPEG4 video with MP3 audio, capture video without worrying about the 2GB barrier, or just multiplex audio and video into a single AVI stream. A must-have piece of software for everyone! VirtualDub is free, copylefted software, with full source code available for use in GNU GPL programs. VirtualDub v1.3c still has ASF support. The latest version of VirtualDub is also available and it is recommended to use the latest version unless you really need ASF support. VirtualDub has the capability to load third-party DLLs that include their own video filters. The filters that are built into VirtualDub use the same interface that is exported to DLLs, so you can write filters similar to or better than the included ones. You can sample some of these at the third-party filters page; these range from corrective filters, such as noise reducers, to synthesis filters, such as the subtitler. The basic interface is simple to work with: VirtualDub gives you a 32-bit ARGB bitmap to modify. Requirements for the filter SDK: * A 32-bit Windows C++ compiler. Microsoft Visual C++ 6.0 Service Pack 5 recommended; it is possible to write filters in Borland C++ Builder but I cannot help you with this. Microsoft Visual Studio .NET has not been tested with this SDK and is not recommended. * VirtualDub 1.2 or newer (viable V1.4.11 build tree recommended to build debug builds). VirtualDub filters can be loaded manually by clicking on the Load button that appears in the Add Filters dialog box. They can also be automatically loaded at startup if you copy the .vdf file into a plugins subdirectory under the VirtualDub program directory. It is possible, although unusual, for filters to conflict with each other, so if you have problems with a particular filter chain you might want to try testing each filter individually to narrow the scope of the problem.