How to Rip DVD to iPhone 4, Watch DVD Movies on iPhone 4
If you just get an iPhone 4 then you must be dying to put your DVD movies on iPhone 4 for watching. To do that, you have to rip DVD to iPhone 4 video format. However, the process of converting DVD movies to a format that can be used on an iPhone 4 is not installed within iTunes but must be done through third party software called DVD to iPhone 4 Converter. This software can convert movies to the correct iPhone4 format and will allow you copy DVD movies to your iPhone 4 for viewing.
Now, let me explain how to rip DVD to iPhone 4 step by step.
Step 1 Download 4Videosoft DVD to iPhone Converter for Windows. Install and run the program.

Step 2 Now click "Load DVD" to import DVD chapters and titles to the program. Or, you can directly load DVD folder from your hard driver.
The imported DVD movies are displayed in the panel. You can now decide to rip the whole DVD movies or only certain title/chapter of the movie by checking/unchecking the chapters.
Step 3 Set the output profile for your device. We would recommend you set the output file to MP4 that works with iPhone 4 perfectly. Then, choose the output dir for the converted movies at "Destination".

Before converting, you can set the output parameters to match your personal needs. Two important considerations with video playback and the quality of the resulting file are the resolution and the bit-rate.
Naturally, the higher that both of these numbers are, the better the quality of the resulting image will be. However, if your original source video is already at a smaller resolution, there is absolutely no point in encoding it in any higher resolution or bit-rate, as you're not going to magically gain any resolution that wasn’t there in the first place.
Step 4 Now, you are ready to convert DVD movies. Just hit the "Start" for converting.