: If your default player won't open it, use the VLC Media Player . It can play almost any MP4 file, even those with missing headers or unusual codecs.
If you have found this file on a hard drive or SD card and want to see what it is: g_147.mp4
"g_147.mp4" is not a commercial film or a widely known media production with public reviews. Instead, it is a likely produced by a recording device or software. While there is no "complete review" for this specific file, Common Sources for This Naming Convention : If your default player won't open it,
: Right-click the file and select Properties (Windows) or Get Info (Mac). Look for the "Date Created" or "Origin" to see when and where it was filmed. Instead, it is a likely produced by a
: Check the "Camera Model" field in the file's extended properties to identify which device captured the footage. Default File Name - GoPro Support