MPEG4

• MPEG1 Video and Audio Compression (CDrom)

• 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.