Exact Discrete-Time Realization of a Dolby B Encoding/Decoding Architecture

Federico Avanzini; Federico Fontana
DAFx-2006 - Montreal
An algebraic technique which computes nonlinear, delay-free digital filter networks is applied to model the Dolby B in the discretetime. The model preserves the topology of the analog system, and imports the characteristics of the nonlinear processing blocks which are responsible of the peculiar functioning of Dolby B. The resulting numerical system exhibits qualitatively similar dynamic behavior and performance – full compliance with the Dolby B specifications would be achieved by deriving, from comprehensive data sheets of the system, accurate discrete-time models of the analog processing blocks. Results demonstrate that the computation converges if proper iterative methods are employed.