Adaptive Encoders: The New Generation of MPEG-2 Encoders

Whereas current debates concern more object oriented technologies, such as the MPEG-4 standardization process, this paper would like to state the art concerning the MPEG-2 technology. The standard was adopted 4 years ago, and is now currently used for broadcasting digital TV worldwide. Some comments and requirements from the first field trials require new generation of MPEG-2 compression systems, and it was the objective of this paper to try to give some inputs for them. — Whereas the first generations were mainly an optimization of the TM5 model with new motion estimators, new bit-rate control strategies and sometimes new mode selection algorithms, this new generation will be adaptive to the picture content and complexity. This adaptation concerns either the input data (such as picture resolution, noise reduction) or the encoder itself (GOP structure, local adaptation, multipass encoding), but also the bandwidth (statistical multiplexing). From the results presented in this paper a 20% to 30% bits saving can be expected on average, and locally more than 50% (for special cases where the encoders fails, i.e. noise, scene cuts, fading,) — After being in the cost and system software, the competition is now clearly on the compression efficiency to add as many programs as possible into one single channel. The new techniques developed and introduced in this phase of optimization will certainly be exploited in future standards such as MPEG-4 or MPEG-7 where respectively segmentation and scene characterization will be key technologies.

Published

1999-07

Content type

Original Research

DOI

10.5594/M001191

ISBN

978-1-61482-948-5