3GP video files are actually not files at all, but containers holding both the video and audio streams of a specific video. When played back on a device, the video and audio streams sync up and the end result is a movie or home video being played back on your mobile phone. 3GP videos are usually the type of file made when recording videos with your mobile device.
MP4, or Moving Picture Expert Group-4, is another video file that can be played on the Sony 580i. MP4 is the standard video file that is playable on nearly every mobile device, as well as computers and DVD players. MP4 first came to the digital video scene in 1998, and by 1999, it was designated the standard video format by which devices could develop for.
The Sony 580i Walkman Phone comes with the standard USB 2.0 data cable. Connecting the 580i to your computer with the data cable automatically places it into USB mode. When in USB mode, the 580i is accessible from your computer. Place your video files into the "DCIM" folder on the 580i memory to be able to play it back after disconnecting it from your computer.
It becomes a problem for consumers when their personal video files are not the ones supported by the device they want to play them on. If this is the case for you, you can easily convert all your video files into the MP4 or 3GP video format. This means if you have a plethora of AVI, MKV or any other video file format, you can simply convert them in order to be able to watch them from your Sony 580i.