Patents by Inventor Grant A. Davidson

Grant A. Davidson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9135907
    Abstract: A method and apparatus for enhancing a desired audio signal for delivery through an electroacoustic channel include obtaining a noise estimate attributable to an external disturbance, applying the noise estimate to a dynamic noise compensation (DNC) process to thereby condition the desired audio signal as a function of the spectral characteristics of the noise estimate, applying the noise estimate to an adaptive equalization (AEQ) process to thereby condition the desired audio signal as a function of the electroacoustic response of the electroacoustic channel, and applying the noise estimate to an active noise cancellation (ANC) process configured to generate anti-noise for delivery into the electroacoustic channel.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: September 15, 2015
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Matthew C. Fellers, Alan J. Seefeldt, Brett G. Crockett, Grant A. Davidson, Louis D. Fielder
  • Publication number: 20140324441
    Abstract: A method for determining mantissa bit allocation of audio data values of frequency domain audio data to be encoded. The allocation method includes a step of determining masking values for the audio data values, including by performing adaptive low frequency compensation on the audio data of each frequency band of a set of low frequency bands of the audio data. The adaptive low frequency compensation includes steps of: performing tonality detection on the audio data to generate compensation control data indicative of whether each frequency band in the set of low frequency bands has prominent tonal content; and performing low frequency compensation on the audio data in each frequency band in the set of low frequency bands having prominent tonal content as indicated by the compensation control data, but not performing low frequency compensation on the audio data in any other frequency band in the set of low frequency bands.
    Type: Application
    Filed: July 7, 2014
    Publication date: October 30, 2014
    Applicants: DOLBY INTERNATIONAL AB, DOLBY LABORATORIES LICENSING CORPORATION
    Inventors: Arijit BISWAS, Vinay MELKOTE, Michael SCHUG, Grant A. DAVIDSON, Mark S. VINTON
  • Publication number: 20130179175
    Abstract: A method for determining mantissa bit allocation of frequency domain audio data to be encoded, including by performing adaptive low frequency compensation on each frequency band of a set of low frequency bands of the data. The low frequency compensation includes steps of: performing tonality detection on the audio data to generate compensation control data indicative of whether each frequency band in the set has prominent tonal content; and performing low frequency compensation on each frequency band in the set having prominent tonal content, including by correcting a preliminary masking value for each frequency band having prominent tonal content, but not performing low frequency compensation on the audio data in any other frequency band in the set. Other aspects are audio encoding methods including such tonality detection and low frequency compensation steps, and a system configured to perform any embodiment of the inventive method.
    Type: Application
    Filed: August 17, 2012
    Publication date: July 11, 2013
    Applicant: DOLBY LABORATORIES LICENSING CORPORATION
    Inventors: Arijit Biswas, Vinay Melkote, Michael Schug, Grant A. Davidson, Mark S. Vinton
  • Publication number: 20130083939
    Abstract: A method and apparatus for enhancing a desired audio signal for delivery through an electroacoustic channel include obtaining a noise estimate attributable to an external disturbance, applying the noise estimate to a dynamic noise compensation (DNC) process to thereby condition the desired audio signal as a function of the spectral characteristics of the noise estimate, applying the noise estimate to an adaptive equalization (AEQ) process to thereby condition the desired audio signal as a function of the electroacoustic response of the electroacoustic channel, and applying the noise estimate to an active noise cancellation (ANC) process configured to generate anti-noise for delivery into the electroacoustic channel.
    Type: Application
    Filed: June 16, 2011
    Publication date: April 4, 2013
    Applicant: DOLBY LABORATORIES LICENSING CORPORATION
    Inventors: Matthew C. Fellers, Alan J. Seefeldt, Brett G. Crockett, Grant A. Davidson, Louis D. Fielder
  • Patent number: 5632003
    Abstract: The invention relates in general to low bit-rate encoding and decoding of information such as audio information. More particularly, the invention relates to computationally efficient adaptive bit allocation and quantization of encoded information useful in high-quality low bit-rate coding systems.In one embodiment, an audio split-band encoder splits an input signal into frequency subband signals, quantizes the subband signals according to values established by an allocation function, and assembles the quantized subband signals into an encoded signal. The allocation function establishes allocation values in accordance with psychoacoustic principles based upon a masking threshold.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: May 20, 1997
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Grant A. Davidson, Craig C. Todd, Mark F. Davis, Brian D. Link, Louis D. Fielder
  • Patent number: 5579404
    Abstract: A signal processing system comprising components such as split-band perceptual coders can receive a peak amplitude limited input audio signal and can process the signal in such a manner that the processed signal preserves the apparent loudness of the input signal but is no longer peak-amplitude limited. In one embodiment, upsampling is used in estimating the resultant peak amplitude and gain factors established in response to the estimated peak amplitude are applied to one or more frequency subbands of the processed signal.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: November 26, 1996
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Louis D. Fielder, Marina Bosi-Goldberg, Grant A. Davidson, Kenneth J. Gundry
  • Patent number: 5479562
    Abstract: The invention relates to formatting encoded audio information in a form suitable for transmission or storage. Audio information is encoded into a binary form, using an invariant number of bits to represent at least some but not all of the encoded information. The information represented by an invariant number of bits is assembled into pre-established positions within a formatted frame.
    Type: Grant
    Filed: June 18, 1993
    Date of Patent: December 26, 1995
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Louis D. Fielder, Grant A. Davidson
  • Patent number: 5451954
    Abstract: The invention relates in general to low bit-rate encoding and decoding of information such as audio information. More particularly, the invention relates to the suppression of quantizing noise which results from low bit-rate encoding and decoding of signal events such as transients. An encoder identifies intervals of an input signal in which a decoder is likely to generate audible artifacts caused by quantizing errors. Indications of these intervals are passed in the encoded signal to the decoder. The decoder uses these indications to eliminate quantizing artifacts by suppressing corresponding intervals in the output signal.
    Type: Grant
    Filed: August 4, 1993
    Date of Patent: September 19, 1995
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Mark F. Davis, Craig C. Todd, Grant A. Davidson, Stephen D. Vernon
  • Patent number: 5394473
    Abstract: The 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.
    Type: Grant
    Filed: December 11, 1991
    Date of Patent: February 28, 1995
    Assignee: Dolby Laboratories Licensing Corporation
    Inventor: Grant A. Davidson
  • Patent number: 5297236
    Abstract: The invention relates in general to digital encoding and decoding of information. More particularly, the invention relates to efficient implementation of digital analysis and synthesis filter banks used in encoding and decoding. The invention permits the length of a digital transform used to implement critically-sampled analysis and synthesis filter banks to be adaptively selected.
    Type: Grant
    Filed: June 5, 1991
    Date of Patent: March 22, 1994
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Michael B. Antill, Grant A. Davidson
  • Patent number: 5230038
    Abstract: A transform encoder, a transform decoder, and a transform encoder/decoder system utilize complex pre- and post-transform multiplication of input signal samples to implement concurrent application of a modified Discrete Cosine Transform and a modified Discrete Sine Transform according to the Evenly-Stacked Time Domain Aliasing Cancellation technique against two channels of input signal samples, and to reduce the computational complexity of a digital filter bank of a modified Discrete Cosine Transform.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: July 20, 1993
    Inventors: Louis D. Fielder, Grant A. Davidson
  • Patent number: 5142656
    Abstract: A transform encoder, a transform decoder, and a transform encoder/decoder system employ adaptive bit allocation wherein each code word representing spectral information is allocated a fixed number of bits and an adaptive number of bits, except that at least some but not all code words are allocated a fixed number of bits.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: August 25, 1992
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Louis D. Fielder, Grant A. Davidson
  • Patent number: 5109417
    Abstract: Quantizing noise is lessened in a speech signal system by using adaptive bit allocation for subband channels, wherein subband information of digital words is represented in block-floating-point form, and normalized mantiss as may allow dropping a sign bit.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: April 28, 1992
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Louis D. Fielder, Grant A. Davidson