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.

Graphics

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.

Bandwidth

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.

Compatibility

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.