Your preferred (such as Bash, Python, or PowerShell)
A: Possibly. Look for archivefhdsone454 1mp4 full and archivefhdsone454 2mp4 full – they could be split parts of a long recording (e.g., camera automatically splitting every 4GB due to FAT32 limits). archivefhdsone454 2mp4 full
If no errors, it’s valid MP4.