Use the program either as a plug-in for Adobe Premiere 5.x or by itself. The first frame of the .avi file you select will be displayed in a window, and may be played. Then, specify a name for the output MPEG file and choose properties for frame operations, cropping, and output resolution. Press the Start Encoding button and in just a bit the process will be complete. You may preview the output as well.
Source code is available.