Regulated by the Moving Picture Experts Group (MPEG), MPEG-3 refers to coding standards for high definition television (HDTV) signals. The group is part of the International Organization for Standardization. Since 1988, the group has been responsible for creating both video and audio coding standards.

It is important to note that the specific MPEG-3 standard no longer exists, and that the standards set forth within it are now a part of MPEG-2. When the group originally took on the responsibility for setting MPEG-3 regulations for HDTV in 1992, they were simultaneously working on what is called MPEG-2. It was discovered, however, that MPEG-2 encoding could accommodate HDTV signals as well. The MPEG-3 standard was therefore discontinued.

The MPEG-2 supplies coding standards for all HDTV signals that are sent at 1080p, which is a shorthand term for the video mode known as full high definition. In addition, MPEG-2 includes coding standards for all broadcast signals. This includes digital satellite and cable TV, as well as protocol for digital video disks (DVDs).

MPEG-2, including its standardization of HDTV that was formerly known as MPEG-3, is only one of five formats that the Moving Picture Experts Group oversees. The organization is also responsible for MPEG-1, which handles the audio coding standards for the popular MP3 music format, and MPEG-4, which offers coding standards for 3D content. Two other coding standards that deal with multimedia content fall under their umbrella, as well.

The standards put forth by the Moving Picture Experts Group offer a reliable and consistent method for coding video, as well as audio. At its most basic, video and audio coding refers to the way that electrical and computer engineers turn data into what is seen on television screens or heard on MP3 players. This transformation of data into real sound and visible images is quite complex and technical. At its core, the process is essentially threefold: compressed data is transferred into more recognizable samples; the samples of picture and sound are then cut into smaller segments; and then these segments are transformed into a frequency that can be coded and transmitted.

MPEG-2 goes a step beyond this basic process. Thanks to sophisticated technology, the standards allow the raw picture data to be predicted based on reconstructed images that have been seen in other things before. Then, only data that is different from the old images must be coded to create the video that viewers see.