Most of movie files stored in your computer may be AVI video format and we don't know how to get them into iPhone 4. Simply, iPhone 4 supports some types of video cameras watch AVI footage via the camera card reader accessory, while it won't let you play downloaded AVI movies on the iPhone 4. If you want to play AVI movies downloaded from the internet or computer on you iPhone 4, you can convert your AVI to iPhone 4 friendly format.
Cucusoft DVD to iPhone 4 Converter Suite makes everything becomes so easy. It can convert AVI to iPhone 4 compatible format like MP4, MOV or M4V with its optimized presets. So you don't need to worry about the settings for your iPhone 4.
Tips: If you are a Mac user, you need a Mac version of conversion software. We recommend this one: iPhone 4 Converter Mac.
Step 1: Free download Cucusoft DVD to iPhone 4 Converter Suite and install the software on your PC. Click the second button on the main interface to run iPhone Video Converter.

Step 2: Then click "Open fIle" button on the interface of iPhone Video Converter to choose the AVI file you want to convert.
Step 3: Choose output profile in the "Profile" pull-down list. Click "Output" button to select the output folder.

Step 4: Click "Convert" button to start converting AVI video to iPhone 4.
While the conversion is going, You can preview the movie by the screen of the little "iPhone" under the control panel. The output folder will be opened automatically when the conversion have finished. Then , you can transfer the AVI movie to your iphone 4 with iTunes and enjoy yourself.
Related Guides:
Convert DVD movie to iPhone 4
Play YouTube videos on iPhone 4
WMV to iPhone 4