123 AVI to GIF Converter is a image-video-image converter for Windows. The application can convert both GIF animated images to AVI, and AVI video files to GIF files. The user interface is divided in two tabs, according to what you intend to do. The default view is AVI to GIF conversion, which is easier than GIF to AVI.
When you want to convert AVI to GIF, you can simply convert the whole file or specify the starting and ending frames. 123 AVI to GIF Converter also allows you to crop the source image and resize it. However, you have to do this by eye. You simply write a number of pixels on the Left and Top fields and the program will then make the calculations for you. It would definitely be easier to just select the area with your mouse. You are also given two options for defining the settings of the GIF movie you are making. You can define the Loop and the Frame Delay. If you set a Loop of 0, the GIF will repeat forever. There are also some color options to play with.
The GIF to AVI process is less customizable. You can only crop the source and resize the image. I don't see any general options, so everything has to be done from the main graphical user interface.