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MPEG-4, introduced in 1998, is the designation for a group of audio and video coding standards agreed upon by MPEG (Moving Picture Experts Group). MPEG-4 is primarily designed to handle low bit rate content, from 4800 bit/s to approximately 4 Mbit/s. The primary uses for the MPEG-4 standard are web ( streaming media) and CD distribution, conversational ( videophone), and broadcast television. MPEG-4 absorbs many of the features of MPEG-1 and MPEG-2MPEG-2 (1994) is the designation for a group of audio and video coding standards agreed upon by MPEG (Moving Pictures Experts Group), and published as ISO standard 13818. MPEG-2 is typically used to encode audio and video for broadcast signals, including, adding new features such as (extended) VRMLVRML Virtual Reality Modeling Language sometimes pronounced vermal is a standard file format for representing 3-dimensional (3D) interactive vector graphics, designed particularly with the World Wide Web in mind. It is a text file format where, e. vertice support for 3D rendering, object-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 developerThe term developer has many meanings: A software developer, one who does computer programming or designs the system to match the requirements of a systems analyst. A real estate developer, one who builds on land or changes and enhances the use of an exists 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 is a compression codec for video signals.
- Layer 3 is a 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).
- Layer 10 is an advanced codec for video signals also called H.264264 is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective effort known as the Joint Video Team (JVT). This sta.
The designated container for MPEG-4 content is MP4MP4 is the "official" container for MPEG-4 media types defined by the Moving Picture Experts Group. It is, or will be, typically used to store data in files, though it will be used in data streams and possibly in other ways. MP4 thus allows streaming over, which was also defined within MPEG-4.
MPEG-7MPEG-7 is a multimedia content description standard. Thus, it is not a standard which deals with the actual coding of moving pictures and audio, like MPEG-1, MPEG-2 and MPEG-4. It uses XML to store metadata, and can be attached to timecode in order to tag and MPEG-21The MPEG-21 standard, from the Moving Picture Experts Group aims at defining an open framework for multimedia applications. See also Digital Rights Management External links . serve other purposes.
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