If is one of several clips (common with cameras like Canon or GoPro that split long recordings), you can stitch them together:
To do more than just join clips, such as adding text or trimming parts: g61029.mp4
For advanced work, Adobe Premiere Pro or the free DaVinci Resolve are industry standards for editing MP4 files. 3. Troubleshooting Playback If you're having trouble opening the file: If is one of several clips (common with