Right-click the file, select Properties , and go to the Details tab to see the date created, frame width, and length. On Mac: Right-click the file and select Get Info .
If the file won't open in your default player, the VLC Media Player is a reliable, free tool that can handle almost any MP4 codec. 770054949544_3(1).mp4
If you received this file as an attachment from an unknown sender, it is best not to open it, as unusual filenames can sometimes be used to disguise malicious content. Right-click the file, select Properties , and go
If you have this file and want to know what it is without opening it blindly, you can check its metadata: Right-click the file