Patents by Inventor Michael John Smithers
Michael John Smithers 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).
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Patent number: 8731215Abstract: Scaling, by a desired amount sm, the overall perceived loudness Lm of a multichannel audio signal, wherein perceived loudness is a nonlinear function of signal power P, by scaling the perceived loudness of each individual channel Lc by an amount substantially equal to the desired amount of scaling of the overall perceived loudness of all channels sm subject to accuracy in calculations and the desired accuracy of the overall perceived loudness scaling sm. The perceived loudness of each individual channel may be scaled by changing the gain of each individual channel, wherein gain is a scaling of a channel's power. Optionally, in addition, the loudness scaling applied to each channel may be modified so as to reduce the difference between the actual overall loudness scaling and the desired amount of overall loudness scaling.Type: GrantFiled: December 27, 2011Date of Patent: May 20, 2014Assignee: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Michael John Smithers
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Patent number: 8504181Abstract: Processing an audio signal represented by the Modified Discrete Cosine Transform (MDCT) of a time-sampled real signal is disclosed in which the loudness of the transformed audio signal is measured, and at least in part in response to the measuring, the loudness of the transformed audio signal is modified. When gain modifying more than one frequency band, the variation or variations in gain from frequency band to frequency band, is smooth. The loudness measurement employs a smoothing time constant commensurate with the integration time of human loudness perception or slower.Type: GrantFiled: March 30, 2007Date of Patent: August 6, 2013Assignee: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Brett Graham Crockett, Michael John Smithers
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Patent number: 8488811Abstract: A method and apparatus for limiting the absolute magnitude of an audio signal. The method may include firstly variable-gain reducing the gain of an audio signal, and then secondly variable-gain reducing the gain of the audio signal faster than the first variable-gain reduction, thereby limiting the absolute magnitude of the audio signal to a threshold. The first variable-gain reduction may include variable-gain reducing the gain of the audio signal in a first stage, and the second variable-gain reduction may include variable-gain reducing the gain of the audio signal in a second stage that reduces the gain faster than the first stage. The second variable-gain reduction may include delaying the audio signal, finding a peak among the delayed audio signal, calculating a fast gain from a found peak, and modifying the delayed audio signal with the calculated fast gain.Type: GrantFiled: August 8, 2007Date of Patent: July 16, 2013Assignee: Dolby Laboratories Licensing CorporationInventors: Michael John Smithers, Brett Graham Crockett, David Stanley McGrath
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Patent number: 8437482Abstract: One or a combination of two or more specific loudness model functions selected from a group of two or more of such functions are employed in calculating the perceptual loudness of an audio signal. The function or functions may be selected, for example, by a measure of the degree to which the audio signal is narrowband or wideband. Alternatively or with such a selection from a group of functions, a gain value G[t] is calculated, which gain, when applied to the audio signal, results in a perceived loudness substantially the same as a reference loudness. The gain calculating employs an iterative processing loop that includes the perceptual loudness calculation.Type: GrantFiled: May 27, 2004Date of Patent: May 7, 2013Assignee: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Michael John Smithers, Brett Graham Crockett
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Patent number: 8239050Abstract: Measuring the loudness of audio encoded in a bitstream that includes data from which an approximation of the power spectrum of the audio can be derived without fully decoding the audio is performed by deriving the approximation of the power spectrum of the audio from said bitstream without fully decoding the audio, and determining an approximate loudness of the audio in response to the approximation of the power spectrum of the audio. The data may include coarse representations of the audio and associated finer representations of the audio, the approximation of the power spectrum of the audio being derived from the coarse representations of the audio. In the case of subband encoded audio, the coarse representations of the audio may comprise scale factors and the associated finer representations of the audio may comprise sample data associated with each scale factor.Type: GrantFiled: March 23, 2006Date of Patent: August 7, 2012Assignee: Dolby Laboratories Licensing CorporationInventors: Brett Graham Crockett, Michael John Smithers, Alan Jeffrey Seefeldt
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Publication number: 20120106743Abstract: Scaling, by a desired amount sm, the overall perceived loudness Lm of a multichannel audio signal, wherein perceived loudness is a nonlinear function of signal power P, by scaling the perceived loudness of each individual channel Lc by an amount substantially equal to the desired amount of scaling of the overall perceived loudness of all channels sm subject to accuracy in calculations and the desired accuracy of the overall perceived loudness scaling sm. The perceived loudness of each individual channel may be scaled by changing the gain of each individual channel, wherein gain is a scaling of a channel's power.Type: ApplicationFiled: December 27, 2011Publication date: May 3, 2012Applicant: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Michael John Smithers
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Publication number: 20110311062Abstract: Scaling, by a desired amount sm, the overall perceived loudness Lm of a multichannel audio signal, wherein perceived loudness is a nonlinear function of signal power P, by scaling the perceived loudness of each individual channel Lc by an amount substantially equal to the desired amount of scaling of the overall perceived loudness of all channels sm, subject to accuracy in calculations and the desired accuracy of the overall perceived loudness scaling sm. The perceived loudness of each individual channel may be scaled by changing the gain of each individual channel, wherein gain is a scaling of a channel's power. Optionally, in addition, the loudness scaling applied to each channel may be modified so as to reduce the difference between the actual overall loudness scaling and the desired amount of overall loudness scaling.Type: ApplicationFiled: August 22, 2011Publication date: December 22, 2011Applicant: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Michael John Smithers
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Patent number: 8032385Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.Type: GrantFiled: September 24, 2009Date of Patent: October 4, 2011Assignee: Dolby Laboratories Licensing CorporationInventors: Michael John Smithers, Jeffrey Charles Riedmiller, Charles Quito Robinson, Brett Graham Crockett
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Patent number: 8019095Abstract: Scaling, by a desired amount sm, the overall perceived loudness Lm of a multichannel audio signal, wherein perceived loudness is a nonlinear function of signal power P, by scaling the perceived loudness of each individual channel Lc by an amount substantially equal to the desired amount of scaling of the overall perceived loudness of all channels sm, subject to accuracy in calculations and the desired accuracy of the overall perceived loudness scaling sm. The perceived loudness of each individual channel may be scaled by changing the gain of each individual channel, wherein gain is a scaling of a channel's power. Optionally, in addition, the loudness scaling applied to each channel may be modified so as to reduce the difference between the actual overall loudness scaling and the desired amount of overall loudness scaling.Type: GrantFiled: March 14, 2007Date of Patent: September 13, 2011Assignee: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Michael John Smithers
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Publication number: 20100250258Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.Type: ApplicationFiled: September 24, 2009Publication date: September 30, 2010Applicant: Dolby Laboratories Licensing CorporationInventors: Michael John Smithers, Jeffrey Charles Riedmiller, Charles Quito Robinson, Brett Graham Crockett
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Publication number: 20100202632Abstract: Scaling, by a desired amount sm, the overall perceived loudness Lm of a multichannel audio signal, wherein perceived loudness is a nonlinear function of signal power P, by scaling the perceived loudness of each individual channel Lc by an amount substantially equal to the desired amount of scaling of the overall perceived loudness of all channels sm, subject to accuracy in calculations and the desired accuracy of the overall perceived loudness scaling sm. The perceived loudness of each individual channel may be scaled by changing the gain of each individual channel, wherein gain is a scaling of a channel's power.Type: ApplicationFiled: March 14, 2007Publication date: August 12, 2010Applicant: Dolby Laboratories Licensing CorporationInventors: Alan Jeffrey Seefeldt, Michael John Smithers
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Publication number: 20090304190Abstract: Processing an audio signal represented by the Modified Discrete Cosine Transform (MDCT) of a time-sampled real signal is disclosed in which the loudness of the transformed audio signal is measured, and at least in part in response to the measuring, the loudness of the transformed audio signal is modified. When gain modifying more than one frequency band, the variation or variations in gain from frequency band to frequency band, is smooth. The loudness measurement employs a smoothing time constant commensurate with the integration time of human loudness perception or slower.Type: ApplicationFiled: March 30, 2007Publication date: December 10, 2009Applicant: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alan Jeffrey Seefeldt, Brett Graham Crockett, Michael John Smithers
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Publication number: 20090304213Abstract: A method for reducing phase differences varying with frequency occurring at certain listening positions with respect to loudspeakers reproducing respective ones of multiple sound channels in a listening space, the phase differences occurring in a sequence of frequency bands in which the phase differences alternate between being predominantly in-phase and predominantly out-of-phase, comprises adjusting the phase in multiple frequency bands in which the multiple sound channels are out-of-phase at such listening positions. Such adjustment of phase includes the frequency bands in which the width of comb filtering pass bands and notches resulting from phase differences at such listening positions would be greater than or commensurate with the critical band width if the phase adjustment were not applied. The listening space may be the interior of a vehicle.Type: ApplicationFiled: March 14, 2007Publication date: December 10, 2009Applicant: Dolby Laboratories Licensing CorporationInventors: Bryan Austin Cook, Michael John Smithers
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Publication number: 20090299756Abstract: A hybrid stereophonic/monophonic audio signal encoding comprises generating, in response to a discrete two-channel stereophonic audio signal, an encoded hybrid stereophonic/monophonic audio signal in which the audio signal is a discrete two-channel audio signal below a frequency fm and a single-channel monophonic audio signal above the frequency fm, generating, in response to the discrete two-channel stereophonic audio signal, spatial parameter information characterizing the discrete two-channel stereophonic audio signal above the frequency fm, and combining the hybrid stereophonic/monophonic audio signal with said spatial parameter information in such a manner that the resulting signal is decodable both by a decoder configured to decode a discrete two-channel stereophonic audio signal encoded with the same encoding as applied to the hybrid stereophonic/monophonic audio signal and by a decoder configured to decode, with the use of the spatial parameter information, the hybrid stereophonic/monophonic audio sigType: ApplicationFiled: September 12, 2008Publication date: December 3, 2009Applicant: Dolby Laboratories Licensing CorporationInventors: Mark Franklin Davis, Michael John Smithers
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Patent number: 7617109Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness and dynamic range of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.Type: GrantFiled: July 1, 2004Date of Patent: November 10, 2009Assignee: Dolby Laboratories Licensing CorporationInventors: Michael John Smithers, Jeffrey Charles Riedmiller, Charles Quito Robinson, Brett Graham Crockett
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Publication number: 20090271185Abstract: A method and apparatus for limiting the absolute magnitude of an audio signal. The method may include firstly variable-gain reducing the gain of an audio signal, and then secondly variable-gain reducing the gain of the audio signal faster than the first variable-gain reduction, thereby limiting the absolute magnitude of the audio signal to a threshold. The first variable-gain reduction may include variable-gain reducing the gain of the audio signal in a first stage, and the second variable-gain reduction may include variable-gain reducing the gain of the audio signal in a second stage that reduces the gain faster than the first stage. The second variable-gain reduction may include delaying the audio signal, finding a peak among the delayed audio signal, calculating a fast gain from a found peak, and modifying the delayed audio signal with the calculated fast gain.Type: ApplicationFiled: August 8, 2007Publication date: October 29, 2009Applicant: Dolby Laboratories Licensing CorporationInventors: Michael John Smithers, Brett Graham Crockett, David Standley McGrath
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Patent number: 7508947Abstract: A process for combining audio channels combines the audio channels to produce a combined audio channel and dynamically applies one or more of time, phase, and amplitude or power adjustments to the channels, to the combined channel, or to both the channels and the combined channel. One or more of the adjustments are controlled at least in part by a measure of auditory events in one or more of the channels and/or the combined channel. Applications include the presentation of multichannel audio in cinemas and vehicles. Not only methods, but also corresponding computer program implementations and apparatus implementations are included.Type: GrantFiled: August 3, 2004Date of Patent: March 24, 2009Assignee: Dolby Laboratories Licensing CorporationInventor: Michael John Smithers
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Publication number: 20090067644Abstract: Measuring the loudness of audio encoded in a bitstream that includes data from which an approximation of the power spectrum of the audio can be derived without fully decoding the audio is performed by deriving the approximation of the power spectrum of the audio from said bitstream without fully decoding the audio, and determining an approximate loudness of the audio in response to the approximation of the power spectrum of the audio. The data may include coarse representations of the audio and associated finer representations of the audio, the approximation of the power spectrum of the audio being derived from the coarse representations of the audio. In the case of subband encoded audio, the coarse representations of the audio may comprise scale factors and the associated finer representations of the audio may comprise sample data associated with each scale factor.Type: ApplicationFiled: March 23, 2006Publication date: March 12, 2009Applicant: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Brett Graham Crockett, Michael John Smithers, Alan Jeffrey Seefeldt