The 3GP file format, with the file extension ".3gp", stores video as MPEG-4 Part 14 and H.263 files, and audio streams as AAC and AMR audio files. 3GP's are big endian and the content is also correctly sized for mobile display screens as image sizes and bandwidth are also described in the file. Usually 3GP record by traditional cellphone is in 176 x 144 or 176 x 120, 320 x 240 resolution, but Smart phone rise sharply and current 3GP has up to 720p or 1080p resolution.
What if some friend email you a 3GP file to your iPhone 4S email account or you download a 3GP files on-line for playing? iPhone 4S is not obeying to 3GP recording cellphone series. So the easy way is to convert 3GP movies to iPhone 4S supported MP4, H.264 format. And the toolkit to use is right the 3GP to iPhone 4S Converter for Mac. With it, you will be able to convert all kinds of 3GP files from common cellphone, current Android Phone with any different resolution to iPhone 4S supported MP4, H.264 in a breeze.
Import 3GP videos to 3GP to iPhone 4S Converter from your PC HD drive.
Set iPhone 4S supported format as output.
Go to HD option------Set H.264 1080p/720p
Go to iPhone option ----Set MP4 480p
Click "Start" button to begin M2TS to iPhone 4S Conversion.
Related link: AVI to iPhone 4S Converter for Mac