Dolby Laboratories Licensing Corporation

Corey I Cheng

Michael John Smithers

David N Lathrop

Claus Bauer

Michael J Smithers

Estimates of spectral magnitude and phase are obtained by an estimation process using spectral information from analysis filter banks such as the Modified Discrete Cosine Transform. The estimation process may be implemented by convolution-like operations with impulse responses. Portions of the impulse responses may be selected for use in the convolution-like operations to trade off between computational complexity and estimation accuracy. Mathematical derivations of analytical expressions for filter structures and impulse responses are disclosed.

Coding techniques using estimated spectral magnitude and phase derived from MDCT coefficients

Transmitters and receivers in multiple description coding systems use correlating and decorrelating transforms to generate and process multiple descriptions of elements of an input signal. The multiple descriptions include groups of correlating transform coefficients that permit recovery of an inexact facsimile of the signal if some of the correlating transform coefficients are lost or corrupted during transmission. Noiseless implementations of the correlating and decorrelating transforms are described that allow the signal elements to be quantized with different quantizing resolutions. Implementations using the Fast Hadamard Transform are described that reduce the resources needed to perform the transforms.

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Framingham, MA, United States of America

Corey I Cheng