US05394473Adaptive-block-length, adaptive-transforn, and adaptive-window transform coder, decoder, and encoder/decoder for high-quality audio
AssigneeDolby Laboratories Licensing Corporation
Assign./FiledFeb. 28, 1995/ Dec. 11, 1991
InventorsDavidson; Grant A.
SummaryTransform audio coding with adaptive block length, transform and window. This patent (at least) must cover some of the IP embodied in Minidisc's ATRAC. Description has commonality with other Dolby patents.
AbstractThe invention relates in general to high-quality low bit-rate digital transform coding and decoding of information corresponding to audio signals such as music signals. More particularly, the invention relates to signal analysis/synthesis in coding and decoding. The invention can optimize the trade off in transform coders between time resolution and frequency resolution by adaptively selecting the transform block length for each sampled audio segment, and/or can optimize coding gain by adaptively selecting the transform and/or by adaptively selecting the analysis window or the analysis/synthesis window pair.