I have been using the wonderful djifix.exe, but sometimes it does not repair my videos, so I looked further and found some pieces of software (all console application) which requires a lot of effort and knowledge to build the proper command line, so I made my own GUI application (using those apps, sorry only for Windows) which until now has been able to fix all my P3P damaged videos. I like to share with you all to download, its pretty easy to use. Only choose (browse for) a good video from your disk with the same settings of the damaged one and then choose the damaged video and click fix it, the app will do everything it need to fix it, you will have a new working video in the same folder the application started. I hope it works for you all: download it here
FIX-DJI.zip