lt is an object-oriented compression. In MPEG-4, objects are separated independently from other objects in the picture and compressed to form a file package. Mpeg4 was extensively used in digital video recording and transfer cards and dvr devices before the H.264 compression technology emerged.
The results are very efficient compared to MPEG2 and MJPEG and can be scaled from low bitrate to high bitrate. MPEG4 is two times more efficient than MPEG2. Its history goes back to the late 1990s.
MPEG-4 absorbs many of the MPEG-1 and MPEG-2 and other related standards, adding new features such as (extended) VRML support for 3D rendering, object-oriented composite files (including audio, video, and VRML objects).
Support for externally defined Digital Rights Management and various types of interaction. AAC (Advanced Audio Coding) was standardized in addition to MPEG-2 (as Chapter 7) prior to the release of MPEG-4.
MPEG-4 is still an emerging standard and is broken down into a number of parts. Companies promoting MPEG-4 compliance do not always make it clear which "part" level compliance they are talking about.
The most important things to note are MPEG-4 Part 2 (including the Advanced Simple Profile used by DivX, Xvid, Nero Digital, and codecs like 3ivx and QuickTime 6) and MPEG-4 part 10 (MPEG-4 AVC/H .264 or Advanced Video Coding is used by high definition video media such as x264 encoder, Nero Digital AVC, QuickTime 7 and Blu-ray Disc).
Most of the features available in MPEG-4 are left up to individual developers to decide if implementation is required. This likely means that not all MPEG-4 standards have been fully implemented. To deal with this, the standard incorporates the concept of "profiles" and "levels" and allows a particular set of capabilities to be properly defined for a subset of applications.
MPEG-4 provides the following functions:
- Improved coding efficiency than MPEG-2 [ citation needed ]
- Encoding mixed media data (video, audio, speech)
- Error resilience to ensure robust transmission
- Ability to interact with the audio-visual scene produced at the receiver