: On Windows, right-click the file, select Properties , and go to the Details tab to see the "Date Created" and "Frame Width/Height". This can give you a clue about its origin (e.g., a specific camera resolution).
If you are unsure of the file's origin, treat it with caution to avoid potential malware or "zip bombs" disguised as media. 871605.mp4
: The .mp4 extension is a "container". If it uses an exotic codec (like those found in proprietary security systems), a standard player may fail. You can use MediaInfo to see exactly what is inside the file. : On Windows, right-click the file, select Properties
: Use the VLC Media Player to open it. VLC is safer than standard OS players because it contains its own codecs and rarely executes malicious scripts embedded in a file. : Use the VLC Media Player to open it
Files with purely numerical names like are typically generated by: