The

MPEG The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by International Organization for Standardization, ISO and International Electrotechnical Commission, IEC that sets standards for media coding, includ ...

user data feature provides a means to inject application-specific data into an MPEG

elementary stream An elementary stream (ES) as defined by the MPEG communication protocol is usually the output of an audio encoder or video encoder. An ES contains only one kind of data (e.g. audio, video, or closed caption). An elementary stream is often referred t ...

. User data can be inserted on three different levels: *The sequence level *The

group of pictures In video coding, a group of pictures, or GOP structure, specifies the order in which intra- and inter-frames are arranged. The GOP is a collection of successive pictures within a coded video stream. Each coded video stream consists of successive ...

(GOP) level *The picture data level Applications that process MPEG data do not need to be able to understand data encapsulated in this way, but should be able to preserve it. Examples of information embedded in MPEG streams as user data are: * Aspect ratio information *"Hidden" information per the

Active Format Descriptor In television technology, Active Format Description (AFD) is a standard set of codes that can be sent in the MPEG video stream or in the baseband SDI video signal that carries information about their aspect ratio and other active picture charac ...

specification *

Closed captioning Closed captioning (CC) and subtitling are both processes of displaying text on a television, video screen, or other visual display to provide additional or interpretive information. Both are typically used as a transcription of the audio por ...

per the

EIA-708 CTA-708 (formerly EIA-708 and CEA-708) is the standard for closed captioning for ATSC digital television (DTV) streams in the United States and Canada. It was developed by the Consumer Electronics sector of the Electronic Industries Alliance, w ...

standard

External links

ATSCDVB
ATSC Digital television MPEG {{tech-stub