: MP4 (MPEG-4 Part 14). This is a universal container for digital video and audio, compatible with almost all modern devices. Naming Convention : The "g" prefix is common in:

: If you recently offloaded footage from a GoPro or similar device, this is likely a raw clip from your gallery.

: If the file is not corrupted, your OS should generate a thumbnail giving a visual hint of the location or subject.

: Occasionally, apps that "hide" media will rename files to generic strings like "g_022" to prevent them from being easily identified in a file explorer. How to Identify the Content If you have the file and need to know what is in it safely:

: Use a tool like MediaInfo to see the "Writing Library." This can tell you the specific brand of camera that created the file.

: Right-click the file and select Properties (Windows) or Get Info (Mac) to see the "Date Created." This often reveals the exact time the video was filmed.

: Many budget security systems use a single letter followed by a three-digit sequence (001, 022, etc.).