A syntactic framework for bitstream-level representation of audio-visual objects

We present the design of a novel syntactic and semantic framework to describe the bitstream-level representation of audio-visual information objects. This framework is important for emerging techniques in video compression, and is currently part of the MPEG-4 System Description Language Working Draft. The design is based on a principle of orthogonality between parsing and processing, i.e., separating the bitstream parsing from the other decoding operations, and extends the basic typing system of a programming language so that it incorporates sophisticated parsing information. Examples of object representations are provided using the MPEG-2 video bitstream syntax.