Open the file using a universal player like VLC Media Player , which can handle almost any .mp4 encoding and show you technical information about the video codec used.
Many digital cameras use a sequence of numbers (e.g., YYMMDD or a simple counter) followed by the .mp4 extension. 22601mp4
Where the file was saved (e.g., a folder named "DCIM," "REC," or "DASHCAM") usually reveals the source device. Open the file using a universal player like