公开(公告)号：US12033645B2

公开(公告)日：2024-07-09

申请号：US18376913

申请日：2023-10-05

申请人： DOLBY INTERNATIONAL AB

发明人： Lars Villemoes

IPC分类号： G10L19/02 ,  G10L19/025 ,  G10L19/26 ,  G10L21/038 ,  G10L21/04 ,  H03G3/00 ,  H03G3/30

CPC分类号： G10L19/0208 ,  G10L19/025 ,  G10L19/265 ,  G10L21/038 ,  G10L21/04 ,  H03G3/00 ,  H03G3/3089

摘要： The invention provides an efficient implementation of cross-product enhanced high-frequency reconstruction (HFR), wherein a new component at frequency QΩ+rΩ0 is generated on the basis of existing components at Ω and Ω+Ω0. The invention provides a block-based harmonic transposition, wherein a time block of complex subband samples is processed with a common phase modification. Superposition of several modified samples has the net effect of limiting undesirable intermodulation products, thereby enabling a coarser frequency resolution and/or lower degree of oversampling to be used. In one embodiment, the invention further includes a window function suitable for use with block-based cross-product enhanced HFR. A hardware embodiment of the invention may include an analysis filter bank, a subband processing unit configurable by control data and a synthesis filter bank.

公开(公告)号：US11972768B2

公开(公告)日：2024-04-30

申请号：US17970879

申请日：2022-10-21

申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

发明人： Yutaka Kamamoto ,  Takehiro Moriya ,  Noboru Harada

IPC分类号： G10L19/06 ,  G10L19/02 ,  G10L19/032 ,  G10L21/04 ,  G10L25/06 ,  G10L25/12 ,  G10L25/18 ,  G10L25/27

CPC分类号： G10L19/06 ,  G10L19/0212 ,  G10L19/032 ,  G10L21/04 ,  G10L25/06 ,  G10L25/12 ,  G10L25/18 ,  G10L25/27

摘要： An autocorrelation calculation unit 21 calculates an autocorrelation RO(i) from an input signal. A prediction coefficient calculation unit 23 performs linear prediction analysis by using a modified autocorrelation R′O(i) obtained by multiplying a coefficient wO(i) by the autocorrelation RO(i). It is assumed here, for each order i of some orders i at least, that the coefficient wO(i) corresponding to the order i is in a monotonically increasing relationship with an increase in a value that is negatively correlated with a fundamental frequency of the input signal of the current frame or a past frame.

公开(公告)号：US20240135939A1

公开(公告)日：2024-04-25

申请号：US18397158

申请日：2023-12-27

申请人： Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V. ,  Dolby International AB

发明人： Lars VILLEMOES ,  Per EKSTRAND ,  Sascha DISCH ,  Frederik NAGEL ,  Stephan WILDE

IPC分类号： G10L19/008 ,  G10L19/02 ,  G10L21/038 ,  G10L21/04

CPC分类号： G10L19/008 ,  G10L19/0204 ,  G10L21/038 ,  G10L21/04

摘要： An apparatus for processing an input audio signal relies on a cascade of filterbanks, the cascade having a synthesis filterbank for synthesizing an audio intermediate signal from the input audio signal, the input audio signal being represented by a plurality of first subband signals generated by an analysis filterbank, wherein a number of filterbank channels of the synthesis filterbank is smaller than a number of channels of the analysis filterbank. The apparatus furthermore has a further analysis filterbank for generating a plurality of second subband signals from the audio intermediate signal, wherein the further analysis filterbank has a number of channels being different from the number of channels of the synthesis filterbank, so that a sampling rate of a subband signal of the plurality of second subband signals is different from a sampling rate of a first subband signal of the plurality of first subband signals.

公开(公告)号：US11929089B2

公开(公告)日：2024-03-12

申请号：US16176280

申请日：2018-10-31

申请人： Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.

发明人： Christian Uhle ,  Michael Kratz ,  Paul Klose ,  Timothy Leonard ,  André Luvizotto ,  Sebastian Scharrer

IPC分类号： G10L21/043 ,  G10L19/008 ,  G10L19/02 ,  G10L21/04 ,  G11B27/00 ,  G11B27/28

CPC分类号： G10L21/043 ,  G10L19/008 ,  G10L19/02 ,  G10L21/04 ,  G11B27/005 ,  G11B27/28

摘要： An apparatus for processing a multichannel audio signal has a plurality of channel signals. The apparatus performs a time scale modulation of the multichannel audio signal and has a phase adaptor and a separator. The phase adaptor provides a processed signal by modifying a phase of a signal based on a combination of the channel signals. The separator provides separated signals based on the processed signal. A corresponding method is provided.

公开(公告)号：US11817110B2

公开(公告)日：2023-11-14

申请号：US17829733

申请日：2022-06-01

申请人： DOLBY INTERNATIONAL AB

发明人： Lars Villemoes

IPC分类号： G10L19/02 ,  G10L21/038 ,  G10L21/04 ,  G10L19/025 ,  G10L19/26 ,  H03G3/00 ,  H03G3/30

CPC分类号： G10L19/0208 ,  G10L19/025 ,  G10L19/265 ,  G10L21/038 ,  G10L21/04 ,  H03G3/00 ,  H03G3/3089

摘要： The invention provides an efficient implementation of cross-product enhanced high-frequency reconstruction (HFR), wherein a new component at frequency QΩ+rΩ0 is generated on the basis of existing components at Ω and Ω+Ω0. The invention provides a block-based harmonic transposition, wherein a time block of complex subband samples is processed with a common phase modification. Superposition of several modified samples has the net effect of limiting undesirable intermodulation products, thereby enabling a coarser frequency resolution and/or lower degree of oversampling to be used. In one embodiment, the invention further includes a window function suitable for use with block-based cross-product enhanced HFR. A hardware embodiment of the invention may include an analysis filter bank, a subband processing unit configurable by control data and a synthesis filter bank.

公开(公告)号：US20230238017A1

公开(公告)日：2023-07-27

申请号：US18192982

申请日：2023-03-30

申请人： DOLBY INTERNATIONAL AB

发明人： Lars VILLEMOES

IPC分类号： G10L21/038 ,  G10L19/02 ,  G10L19/022 ,  G10L21/04 ,  G10L25/18 ,  G10L19/032

CPC分类号： G10L21/038 ,  G10L19/0204 ,  G10L19/022 ,  G10L21/04 ,  G10L25/18 ,  G10L19/032

摘要： The present document relates to audio source coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), as well as to digital effect processors, e.g. exciters, where generation of harmonic distortion add brightness to the processed signal, and to time stretchers where a signal duration is prolonged with maintained spectral content. A system and method configured to generate a time stretched and/or frequency transposed signal from an input signal is described. The system comprises an analysis filterbank configured to provide an analysis subband signal from the input signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples, each having a phase and a magnitude. Furthermore, the system comprises a subband processing unit configured to determine a synthesis subband signal from the analysis subband signal using a subband transposition factor Q and a subband stretch factor S. The subband processing unit performs a block based nonlinear processing wherein the magnitude of samples of the synthesis subband signal are determined from the magnitude of corresponding samples of the analysis subband signal and a predetermined sample of the analysis subband signal. In addition, the system comprises a synthesis filterbank configured to generate the time stretched and/or frequency transposed signal from the synthesis subband signal.

公开(公告)号：US11657830B2

公开(公告)日：2023-05-23

申请号：US17158873

申请日：2021-01-26

申请人： BabbleLabs LLC

发明人： Samer Hijazi ,  Kamil Krzysztof Wojcicki ,  Dror Maydan ,  Christopher Rowen

IPC分类号： G10L25/51 ,  G10L21/0364 ,  H04L1/08 ,  H04L1/00 ,  G06N3/086 ,  G10L21/04 ,  G06N3/084 ,  G06N3/04 ,  G10L25/30

CPC分类号： G10L21/0364 ,  G06N3/04 ,  G06N3/084 ,  G06N3/086 ,  G10L21/04 ,  G10L25/30 ,  H04L1/0045 ,  H04L1/08

摘要： Systems and methods are disclosed for data driven radio enhancement. For example, methods may include demodulating a radio signal to obtain a demodulated audio signal; determining a window of audio samples based on the demodulated audio signal; applying an audio enhancement network to the window of audio samples to obtain an enhanced audio segment, in which the audio enhancement network includes a machine learning network that has been trained using demodulated audio signals derived from radio signals; and storing, playing, or transmitting an enhanced audio signal based on the enhanced audio segment.

公开(公告)号：US20230027660A1

公开(公告)日：2023-01-26

申请号：US17954179

申请日：2022-09-27

申请人： DOLBY INTERNATIONAL AB

发明人： Per EKSTRAND ,  Lars VILLEMOES

IPC分类号： G10L19/022 ,  G10L19/24 ,  G10L21/038 ,  G10L21/04 ,  G10L19/02

摘要： The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.

公开(公告)号：US11562755B2

公开(公告)日：2023-01-24

申请号：US17409592

申请日：2021-08-23

申请人： Dolby International AB

发明人： Per Ekstrand ,  Lars Villemoes

IPC分类号： G10L19/22 ,  G10L21/038 ,  G10L21/04 ,  G10L19/24 ,  G10L19/02 ,  G10L19/022

摘要： The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.

公开(公告)号：US11495236B2

公开(公告)日：2022-11-08

申请号：US16878313

申请日：2020-05-19

申请人： Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V. ,  Dolby International AB

发明人： Lars Villemoes ,  Per Ekstrand ,  Sascha Disch ,  Frederik Nagel ,  Stephan Wilde

IPC分类号： G10L19/008 ,  G10L21/038 ,  G10L21/04 ,  G10L19/02

摘要： An apparatus for processing an input audio signal relies on a cascade of filterbanks, the cascade having a synthesis filterbank for synthesizing an audio intermediate signal from the input audio signal, the input audio signal being represented by a plurality of first subband signals generated by an analysis filterbank, wherein a number of filterbank channels of the synthesis filterbank is smaller than a number of channels of the analysis filterbank. The apparatus furthermore has a further analysis filterbank for generating a plurality of second subband signals from the audio intermediate signal, wherein the further analysis filterbank has a number of channels being different from the number of channels of the synthesis filterbank, so that a sampling rate of a subband signal of the plurality of second subband signals is different from a sampling rate of a first subband signal of the plurality of first subband signals.