What Is an MP4 Video File?

By Shannon Keen

MPEG-4, also referred to as MP4, is a graphics and video file type. It's based on the technology used by Apple for its QuickTime programs and files. The file is designed to be transmitted over a narrower bandwidth than similar JPEG and QuickTime files, making it better suited to low bandwidth media like cellphones and broadband Internet connections.


One useful feature of the MPEG-4 video file is its ability to support multiple bits of data in addition to a standard video or audio stream. MPEG-4 files can mix video with a variety of visual elements including text, animation layers in both 2-D and 3-D, and still graphics. They can also support things like stage descriptions, 3-D objects and embedded interactivity features. This ability can prove valuable when the file is being used to create a multimedia presentation.


MPEG-4 files are designed to transmit on a narrow bandwidth to make them more compatible with low bandwidth media including DSL and broadband Internet connections. Bandwidth refers specifically to the amount of data than can be transmitted by a device or connection within a set amount of time. Digital devices and connections express bandwidth in bits per second, or bps. Hertz, or Hz, is used to express the bandwidth of analog devices and connections.


A variety of programs and devices can support MPEG-4 video files. Apple QuickTime 6 and any later edition will support both MP4 file playback and compression. RealMedia uses a licensed plug-in to play back MPEG-4 files. IBM also uses a plug-in to decode MP4s. Companies including Sony, Samsung, JVC and Philips make a number of media devices that support and actively use MP4 files.

Advantages and Disadvantages

MPEG-4 files have both advantages and disadvantages that come with their use. Their compatibility with multiple media players like Real and QuickTime make them preferable to other, more player-specific file types. However, they can play back only archived content. You can't use them to stream live events. Also, MP4 files require you to wait for pre-buffering before viewing content, increasing the amount of time it takes to view the video as a whole.