iPad Video: Never Go from DVD to HD
If you are looking for the best quality from a DVD source on any encoder you will waste your time and disk space if you go from 720 x 480 DVD resolution to the 1024 x 768 HD iPad screen. Never do this as from the real movie quality it doesn’t matter what bit rate you use, you are just adding inexistent quality details that will only use more space.
For DVD movies or videos use the “AppleTV” settings on Handbrake as a maximum quality for reference. The resulting files are about 2 GBs for 2 hour movies and the bitrate is 1800 – 2000. So don’t go beyond this setting for your iPad as you will not gain any quality at all.
Usually a 1.2 – 1.5 GB file for a 90 min movie is all you need and for 2 hours movie 2 GBs is close to the top. Longer movies will obviously need more data.
If you go from an 1920 x 1024 HD BlueRay source down to the 1024 x 768 iPad screen, then it make sense because you are downscaling the movie and the details and quality will fit your iPad screen. You will lose some HD details but those wont matter on your iPad screen.
Even encoding to HD 720p just for iPad watching wont make sense as the details will be there but you wont be able to see them on the iPad screen. Only do this if you are playing the DVD movie from the iPad to a screen that support 1280 x 720 resolution or up to 1920 x 1080.