I had a folder with 685 FLV and F4V files divided between folders I needed to remux or transcode, I tried Handbrake, it didn't recognize the files within the folder, I would have to do one by one manually so that didn't work. I tried Avidemux, the interface was a joke and it closed with errors without even beginning the process. I gave this app a go and wow, super simple! I dragged the files into the input zone, selected the option to repack to mp4, and it even saved with the same file name on the original directories!!!! This application deserves 5 stars, well-done to the developer this just works!