Encyclopedia > MPEG-4

  Article Content


MPEG-4 (1998) is the designation for a group of audio and video coding standards agreed upon by MPEG (Motion Pictures Coding Experts Group). MPEG-4 is primarily designed to handle low bit-rate[?] content, from 4800 bps to approximately 4 Mbps. The primary uses for the MPEG-4 standard are web (streaming media) and CD distribution, conversational (videophone) uses, and broadcast television.

MPEG-4 absorbs many of the features of MPEG-1 and MPEG-2, adding new features such as (extended) VRML support for 3D rendering, object-oriented oriented composite files (including audio, video and VRML objects), support for Digital Rights Management and various types of interactivity.

Most of the 'features' included in MPEG-4 are left to individual developers to implement. This means that there are very few complete implementations of the MPEG-4 standard. Anticipating this, the developers added the concept of 'Profiles', allowing various capabilities to be grouped together.

MPEG-4 consists of several standards (termed "Layers"), as follows:

Layer 1: Describes synchronization and multiplexing of video and audio.
Layer 2: Compression codec for video signals.
Layer 3: Compression codec for perceptual coding of audio signals.
Layer 4: Describes procedures for testing compliance.
Layer 5: Describes systems for Software simulation.
Layer 6: Describes Delivery Multimedia Integration Framework (DMIF)

See also:

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article
East Islip, New York

... out with 28.5% under the age of 18, 6.3% from 18 to 24, 32.3% from 25 to 44, 21.1% from 45 to 64, and 11.8% who are 65 years of age or older. The median age is 37 ...

This page was created in 23.1 ms