Forum Thread: Recording More Than 30 Mins of Video

It's a file system limit with the way SD cards are formatted. Connect your GS3 to your computer and make sure it's set to Mass Storage mode. Your GS3 will show up as a drive. Open up the drive and select all the files in the drive. Copy them to folder. You'll be restoring your files later.

Afterwards, right click on your drive and choose "format". From the drop down option, choose "exFAT" and click format.

WARNING: ALL YOUR DATA WILL BE ERASED!

Your SD card will be formatted so more than 30 minutes of video can be recorded.

With Control Video Recording app for Android you can set the length, size and quality of the video.
https://play.google.com/store/apps/details?id=com.controlvideorecording.controlvideorecording

Had exactly the same problem. ExFAT is not the solution as Samsung prevents videos over 4 GB. The solution is an app that records for a preset time, then automatically start a new recording. I use AutoBoy Dash Cam. I can now record for hours and hours. You then stick the videos back together. There is a slight glitch at the join, but minimal.