MPEG2 Video and Audio Compression
Better quality, but more computing ressource needed
NO 3 .... Mpeg1 Layer3
MPEG4 Aggregation of all possible type of Media + improvement in low bandwidth
video
description of the video in term of objects.
Based on Quicktime for the mix of the different type of data
Based on VRML for the scene graph
Even Java is Part of MPEG4
Moving Picture Experts Group
Divx : a mix of different bricks comming from MPEG4
MPEG-4 has future potential for use in CVEs, but is not a viable technology
in the short to medium
terms, for the following reasons:
MPEG-4 is designed around a model of uni-directional
one to one communication, with "beta"
support for one to many and no support for many to many links
There is little or no provision for any complex
interaction by the user with the MPEG-4 world. In
particular, there is no support for 6DOF input devices such as the Polhemus
or haptic feedback
There is no provision for interaction by multiple
users within the same VE, for instance locking
mechanisms or conflict resolution
Although MPEG-4 is design for real-time decoding, it is not designed for
real-time encoding. There are profound differences between real-time and
non real-time audio and video encoders. The experience of trying to build
video conferencing tools on top of MPEG-2 suggests that any attempt to perform
real-time interactions through MPEG-4 will be fraught with problems and
severely
limited.