binary format for scene description (MPEG) (BIFS)

Binary Format for Scene Description (BIFS) is a scene description language used in MPEG-4 that can be used to describe the spatiotemporal assignment of individual objects in a data stream independently of each other.

With BIFS, objects can be described, hierarchically ordered and grouped in a two- or three-dimensional space, taking the time axis into account.

BIFS relies on the VRML virtual modeling language and can combine different scenes. For example, participants in a video conference could be punched out of the different studio environments and combined into one virtual studio. This technique uses chroma keying, which is known in studio technology as blue keying or green keying.