If a device loses power while recording, it may save the file in a "temporary" state (often labeled with extra tags) because it couldn't finish writing the index.
Sometimes files have two extensions or prefixes (like CPDA). This usually indicates a proprietary format used by specific hardware. Cpda Videomp4 mp4
Alex, a digital forensics specialist, sat before a monitor displaying a single, stubborn file: evidence_backup.cpda.mp4 . If a device loses power while recording, it
He looked for the "FTYP" brand, which tells computers "This is an MP4." a digital forensics specialist
To turn the CPDA data back into a viewable MP4, Alex had to perform a "Header Rebuild":