You can typically open any .mp4 file by double-clicking it to use your computer's default media player (e.g., Windows Media Player or QuickTime).
It could also be a system-generated file name from specialized hardware such as a Panasonic GH4 Go to product viewer dialog for this item. g4_01434.mp4
The G4 prefix is commonly used for files exported from the G4 Viewer Plus , a video management software for fleet and asset management. These files are typically exported in .mp4 format for sharing incident reports. You can typically open any