An adapted H.261 two-layer video codec for ATM networks

Author

Ghanbari, M.

Author_Institution

Dept. of Electron. Syst. Eng., Essex Univ., Colchester, UK

Volume

40

Issue

9

fYear

1992

fDate

9/1/1992 12:00:00 AM

Firstpage

1481

Lastpage

1490

Abstract

An adaptive video codec which can maintain compatibility between the existing digital circuit switched networks and future ATM networks is described. It is based on two-layer coding principles, where in the base layer the H.261 standard video codec is employed. It is shown that a discrete cosine transform (DCT) in the second layer is unnecessary and can be replaced by a simple requantizer which finely quantizes the residue quantization distortions of the transform coefficients of the base layer. Characteristics of this quantizer in terms of nature of quantization and step sizes are studied. Efficient coding and addressing of residual distortions are described. Finally, a two-dimensional variable length code for the quantized residual distortions is given

Keywords

asynchronous transfer mode; codecs; telecommunication standards; video equipment; ATM networks; H.261 standard; adaptive video codec; residual distortions; residue quantization distortions; simple requantizer; two-dimensional variable length code; two-layer coding; Asynchronous transfer mode; Bit rate; Code standards; Digital circuits; Discrete cosine transforms; Helium; Pulse modulation; Quantization; Switching circuits; Video codecs;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.163569

Filename

163569