Patents by Inventor Peter Graham Craven

Peter Graham Craven 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: 11388510
    Abstract: A compact multi-element microphone has two rings of directional sensors. Using simple analog electronics, it delivers first-order outputs with low noise, wide bandwidth and tight transient response. The double-ring structure provides exceptionally high directional fidelity in the horizontal plane, while also keeping out-of-plane behaviour under control. This enables faithful capture of ambience, reflections and reverberation. A non-radial capsule arrangement moderates cavity resonances and reduces shading. Combined with digital electronics, the array can efficiently provide second-order and higher-order horizontal directivities that maintain their performance over a wider frequency range than with prior solutions. Outputs can be mono, two-channel stereo and multichannel surround sound. Applications include 360-degree immersive audio, with-height concert hall recording, and advanced voice capture using electronic steering of beams and nulls.
    Type: Grant
    Filed: June 2, 2017
    Date of Patent: July 12, 2022
    Inventors: Peter Graham Craven, Christopher Julian Travis
  • Publication number: 20210289291
    Abstract: A compact multi-element microphone has two rings of directional sensors. Using simple analog electronics, it delivers first-order outputs with low noise, wide bandwidth and tight transient response. The double-ring structure provides exceptionally high directional fidelity in the horizontal plane, while also keeping out-of-plane behaviour under control. This enables faithful capture of ambience, reflections and reverberation. A non-radial capsule arrangement moderates cavity resonances and reduces shading. Combined with digital electronics, the array can efficiently provide second-order and higher-order horizontal directivities that maintain their performance over a wider frequency range than with prior solutions. Outputs can be mono, two-channel stereo and multichannel surround sound. Applications include 360-degree immersive audio, with-height concert hall recording, and advanced voice capture using electronic steering of beams and nulls.
    Type: Application
    Filed: June 2, 2017
    Publication date: September 16, 2021
    Inventors: Peter Graham Craven, Christopher Travis
  • Patent number: 11095304
    Abstract: Quantisation methods are provided which employ dither techniques to reduce the noise penalty in certain circumstances whilst still removing noise modulation. One method relates to reducing the wordwidth of audio by one bit, while another method relates to burying one bit of data in a pair of signal samples.
    Type: Grant
    Filed: December 18, 2019
    Date of Patent: August 17, 2021
    Assignee: MQA Limited
    Inventors: Peter Graham Craven, Malcolm Law
  • Publication number: 20210193157
    Abstract: Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimising downsampling and upsampling filters to minimise the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.
    Type: Application
    Filed: December 14, 2020
    Publication date: June 24, 2021
    Inventors: Peter Graham Craven, John Robert Stuart
  • Patent number: 10896683
    Abstract: Methods and devices are described for lossless bandsplitting and bandjoining of streams of signal samples using allpass filtering. The bandsplitting operation reformats an original stream into two intermediate streams representing even and odd samples of the original stream, and then matrix filters these to provide two output substreams representing higher frequency components and lower frequency components of the original stream. Conversely, the bandjoining operation matrix filters two subband streams to provide two quantised intermediate substreams, and then interleaves the filtered streams to furnish an output stream, such that the intermediate substreams are the even and odd samples of the output stream.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: January 19, 2021
    Assignee: MQA Limited
    Inventors: Peter Graham Craven, Malcolm Law
  • Publication number: 20200395918
    Abstract: Methods and devices are described for reducing the audible effect of pre-responses in an audio signal. The pre-responses are effectively delayed by employing a digital non-minimum-phase filter, which includes a zero lying outside the unit circle in its z-transform response. This zero is not paired with another zero at a reciprocal position inside the unit circle, as this would linearise the phase modification. The filtering can introduce a greater group delay at the pre-response frequency than at a low frequency, such as 500 Hz or even 0 Hz. The technique can be used to reduce pre-responses in an existing audio signal and also to pre-empt pre-responses that would be introduced to the audio signal by subsequent processing.
    Type: Application
    Filed: August 28, 2020
    Publication date: December 17, 2020
    Inventors: Peter Graham Craven, John Robert Stuart
  • Patent number: 10867614
    Abstract: Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimising downsampling and upsampling filters to minimise the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: December 15, 2020
    Assignee: MQA Limited
    Inventors: Peter Graham Craven, John Robert Stuart
  • Patent number: 10763828
    Abstract: Methods and devices are described for reducing the audible effect of pre-responses in an audio signal. The pre-responses are effectively delayed by employing a digital non-minimum-phase filter, which includes a zero lying outside the unit circle in its z-transform response. This zero is not paired with another zero at a reciprocal position inside the unit circle, as this would linearise the phase modification. The filtering can introduce a greater group delay at the pre-response frequency than at a low frequency, such as 500 Hz or even 0 Hz. The technique can be used to reduce pre-responses in an existing audio signal and also to pre-empt pre-responses that would be introduced to the audio signal by subsequent processing.
    Type: Grant
    Filed: December 3, 2015
    Date of Patent: September 1, 2020
    Inventors: Peter Graham Craven, John Robert Stuart
  • Publication number: 20190057709
    Abstract: Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimising downsampling and upsampling filters to minimise the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.
    Type: Application
    Filed: October 2, 2018
    Publication date: February 21, 2019
    Inventors: Peter Graham Craven, John Robert Stuart
  • Publication number: 20190013032
    Abstract: Methods and devices are described for lossless bandsplitting and bandjoining of streams of signal samples using allpass filtering. The bandsplitting operation reformats an original stream into two intermediate streams representing even and odd samples of the original stream, and then matrix filters these to provide two output substreams representing higher frequency components and lower frequency components of the original stream. Conversely, the bandjoining operation matrix filters two subband streams to provide two quantised intermediate substreams, and then interleaves the filtered streams to furnish an output stream, such that the intermediate substreams are the even and odd samples of the output stream.
    Type: Application
    Filed: December 21, 2016
    Publication date: January 10, 2019
    Inventors: Peter Graham Craven, Malcolm Law
  • Patent number: 10115410
    Abstract: Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimizing downsampling and upsampling filters to minimize the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.
    Type: Grant
    Filed: June 10, 2014
    Date of Patent: October 30, 2018
    Inventors: Peter Graham Craven, John Robert Stuart
  • Patent number: 9940940
    Abstract: An encoding method and encoder is provided for transparent lossless audio watermarking by quantizing an original PCM audio signal twice, each quantization quantizing to a quantization grid. As a PCM signal is inherently already quantized, there are three quantization grids to consider, the first being the quantization grid of the original PCM signal, the second being that of the watermarked signal and the third being that of an intermediate signal. The technique reduces the amount of introduced quantization error, spectrally shapes the error and fully decorrelates signal alterations from the original audio, thus making the error more similar to additive noise. A decoding method and decoder is also provided, as is a method of altering the watermark without fully decoding the encoded signal.
    Type: Grant
    Filed: March 26, 2015
    Date of Patent: April 10, 2018
    Inventors: Peter Graham Craven, Malcolm Law
  • Patent number: 9870777
    Abstract: Methods are disclosed for an encoder to embed a data stream into a quantized PCM digital audio signal and for a corresponding decoder to both retrieve the data stream and losslessly reconstruct the exact original audio. Some methods employ complimentary amplification and attenuation, while others employ gain redistribution. Pre-emphasis and soft clipping techniques are described as methods of losslessly reducing the peak excursion of the PCM audio signal. Also described is the lossless placing of data at predetermined positions within an audio stream.
    Type: Grant
    Filed: October 24, 2012
    Date of Patent: January 16, 2018
    Inventors: Peter Graham Craven, Malcolm Law
  • Publication number: 20170346465
    Abstract: Methods and devices are described for reducing the audible effect of pre-responses in an audio signal. The pre-responses are effectively delayed by employing a digital non-minimum-phase filter, which includes a zero lying outside the unit circle in its z-transform response. This zero is not paired with another zero at a reciprocal position inside the unit circle, as this would linearise the phase modification. The filtering can introduce a greater group delay at the pre-response frequency than at a low frequency, such as 500 Hz or even 0 Hz. The technique can be used to reduce pre-responses in an existing audio signal and also to pre-empt pre-responses that would be introduced to the audio signal by subsequent processing.
    Type: Application
    Filed: December 3, 2015
    Publication date: November 30, 2017
    Inventors: Peter Graham Craven, John Robert Stuart
  • Publication number: 20170116996
    Abstract: An encoding method and encoder is provided for transparent lossless audio watermarking by quantising an original PCM audio signal twice, each quantisation quantising to a quantisation grid. As a PCM signal is inherently already quantised, there are three quantisation grids to consider, the first being the quantisation grid of the original PCM signal, the second being that of the watermarked signal and the third being that of an intermediate signal. The technique reduces the amount of introduced quantisation error, spectrally shapes the error and fully decorrelates signal alterations from the original audio, thus making the error more similar to additive noise. A decoding method and decoder is also provided, as is a method of altering the watermark without fully decoding the encoded signal.
    Type: Application
    Filed: March 26, 2015
    Publication date: April 27, 2017
    Inventors: Peter Graham Craven, Malcolm Law
  • Publication number: 20170110141
    Abstract: Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimising downsampling and upsampling filters to minimise the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.
    Type: Application
    Filed: June 10, 2014
    Publication date: April 20, 2017
    Inventors: Peter Graham Craven, John Robert Stuart
  • Patent number: 9548055
    Abstract: An encoder for digital audio signals at a higher sample rate creates a stream for consumer distribution at a lower sampling rate, with compatibility for standard PCM players without a decoder. In conjunction with a suitable decoder, two enhanced playback options are supported, the first option allowing full lossless reconstruction of a noise-shaped higher sampling rate signal, the second option allowing lossy bandwidth extension even if an intervening transmission chain has truncated the least-significant-bits of the encoder's output signal.
    Type: Grant
    Filed: June 12, 2013
    Date of Patent: January 17, 2017
    Inventors: Peter Graham Craven, Malcolm Law, John Robert Stuart
  • Publication number: 20160005411
    Abstract: Methods and devices are described whereby a representation of an original PCM signal may be reversibly degraded in a controlled manner and information losslessly embedded to produce a streamable PCM signal, which provides a controlled audio quality when played on standard players and conditional access to a lossless presentation of the original PCM signal. Using such techniques allows control over the level of degradation of the signal and also flexibility in the type information of information embedded. Some methods require a song key, which is employed in one or both of the degrading and embedding steps and for creating a token. These methods may further require a user key, which is used to encrypt the song key before creating the token.
    Type: Application
    Filed: February 13, 2014
    Publication date: January 7, 2016
    Inventors: John Robert Stuart, Richard J. Hollinshead, Peter Graham Craven, Malcolm Law
  • Publication number: 20150279378
    Abstract: Methods are disclosed for an encoder to embed a data stream into a quantised PCM digital audio signal and for a corresponding decoder to both retrieve the data stream and losslessly reconstruct the exact original audio. Some methods employ complimentary amplification and attenuation, while others employ gain redistribution. Pre-emphasis and soft clipping techniques are described as methods of losslessly reducing the peak excursion of the PCM audio signal. Also described is the lossless placing of data at predetermined positions within an audio stream.
    Type: Application
    Filed: October 24, 2012
    Publication date: October 1, 2015
    Inventors: Peter Graham CRAVEN, Malcolm LAW
  • Patent number: 9106241
    Abstract: In lossy data compression of a signal using ADPCM, an adaptive decorrelation or “prediction” filter is used to reduce the amplitude of the signal, the spectral dynamic range of the signal also being reduced. This latter reduction is effected in a nonuniform manner, if known techniques are used, with regions of high spectral density being compressed more than regions of low spectral density. The present invention recognises that using a uniform compression ratio results in a better tradeoff between compression and robustness to transmission channel errors. A method is described for obtaining a uniform compression ratio by adjusting coefficients of the decorrelation filter in dependence on coefficients of an adaptive training filter that is fed from the output of the decorrelation filter. A reverse method is also provided along with encoder, decoder and codec implementing the techniques.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: August 11, 2015
    Inventors: Peter Graham Craven, Malcolm Law