| MPEG-4 (with a formal ISO/IEC designation ISO/IEC 14496) standardization was initiated in 1994 to address the requirements of the rapidly converging telecommunication, computer, and TV/film industries. MPEG-4 had a mandate to standardize algorithms for audiovisual coding in multimedia applications, digital television, interactive graphics, and interactive multimedia applications. The functionalities of MPEG-4 cover content-based interactivity, universal access, and compression, and a brief summary of these is provided in Table 1.1. MPEG-4 was finalized in October 1998 and became an international standard in the early months of 1999.
The technologies developed during MPEG-4 standardization, leading to its current use especially in multimedia streaming systems and interactive applications, go significantly beyond the pure compression efficiency paradigm [1] under which MPEG-1 and MPEG-2 were developed. MPEG-4 was the first major attempt within the research community to examine object-based coding, i.e., decomposing a video scene into multiple arbitrarily shaped objects, and coding these objects separately and efficiently. This new approach enabled several additional functionalities such as region of interest coding, adapting, adding or deleting objects in the scene, etc., besides also having the potential to improve the coding efficiency. Furthermore, right from the outset,MPEG-4 was designed to enable universal access, covering a wide range of target bit-rates and receiver devices. Hence, an important aim of the standard was providing novel algorithms for scalability and error resilience. In this book, we use MPEG-41 as the backdrop to describe the underlying principles and concepts behind some of these new technologies that continue to have significant impact in video coding and transmission applications. |
