公开(公告)号：US11017785B2

公开(公告)日：2021-05-25

申请号：US16369728

申请日：2019-03-29

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Kristofer Kjoerling

IPC: G10L19/002 ,  H04S5/00 ,  H04S3/02 ,  G10L19/008 ,  H04S5/02 ,  G10L19/18

Abstract: The application relates to audio encoder and decoder systems. An embodiment of the encoder system comprises a downmix stage for generating a downmix signal and a residual signal based on a stereo signal. In addition, the encoder system comprises a parameter determining stage for determining parametric stereo parameters such as an inter-channel intensity difference and an inter-channel cross-correlation. Preferably, the parametric stereo parameters are time- and frequency-variant. Moreover, the encoder system comprises a transform stage. The transform stage generates a pseudo left/right stereo signal by performing a transform based on the downmix signal and the residual signal. The pseudo stereo signal is processed by a perceptual stereo encoder. For stereo encoding, left/right encoding or mid/side encoding is selectable. Preferably, the selection between left/right stereo encoding and mid/side stereo encoding is time- and frequency-variant.

公开(公告)号：US20200258531A1

公开(公告)日：2020-08-13

申请号：US16796150

申请日：2020-02-20

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Lars Villemoes ,  Pontus Carlsson

IPC: G10L19/008 ,  G10L19/18 ,  G10L19/16 ,  G10L19/02 ,  H04S3/00 ,  G10L19/06

Abstract: The invention provides methods and devices for stereo encoding and decoding using complex prediction in the frequency domain. In one embodiment, a decoding method, for obtaining an output stereo signal from an input stereo signal encoded by complex prediction coding and comprising first frequency-domain representations of two input channels, comprises the upmixing steps of:(i) computing a second frequency-domain representation of a first input channel; and(ii) computing an output channel on the basis of the first and second frequency-domain representations of the first input channel, the first frequency-domain representation of the second input channel and a complex prediction coefficient. The upmixing can be suspended responsive to control data.

公开(公告)号：US20190392844A1

公开(公告)日：2019-12-26

申请号：US16558634

申请日：2019-09-03

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Kristofer Kjoerling

IPC: G10L19/002 ,  H04S5/02 ,  H04S5/00 ,  H04S3/02 ,  G10L19/008

Abstract: Methods and systems encoding a stereo audio signal having a left channel and a right channel are disclosed. The system includes a downmixer for generating a downmix signal and a residual signal from the stereo audio signal in selected frequency bands representing only part of a used audio frequency range of the stereo audio signal, and a decision module for selecting, in a time variant manner, either left/right perceptual encoding or mid/side perceptual encoding. The system also includes a parameter estimator for estimating stereo parameters for reconstructing a stereo image of a portion of the stereo audio signal, and a perceptual encoder for performing either left/right perceptual encoding or mid/side perceptual encoding based on the selecting to generate an encoded output signal. Finally, the system includes a bitstream generator for creating a bitstream signal comprising the encoded output signal.

公开(公告)号：US20190318748A1

公开(公告)日：2019-10-17

申请号：US16456476

申请日：2019-06-28

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Kristofer Kjoerling

IPC: G10L19/002 ,  H04S5/00 ,  G10L19/008 ,  H04S3/02 ,  H04S5/02

Abstract: Methods and systems encoding a stereo audio signal having an original left channel and an original right channel are disclosed. The method includes generating a downmix signal and a residual signal based on the stereo audio signal and determining one or more stereo parameters based on the stereo audio signal. The residual signal covers only a part of an audio frequency range of the stereo signal, and the one or more stereo parameters describing a stereo image of the stereo audio signal. The method further includes analyzing the stereo audio signal and selecting, based on the analyzing, left/right perceptual encoding or mid/side perceptual encoding in a time variant manner.

公开(公告)号：US20190287541A1

公开(公告)日：2019-09-19

申请号：US16431081

申请日：2019-06-04

Applicant: DOLBY INTERNATIONAL AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Lars Villemoes

IPC: G10L19/008 ,  G10L19/16 ,  H04S3/00 ,  G10L19/06 ,  G10L19/02

Abstract: The invention provides methods and apparatuses for encoding a stereo audio signal having a left channel and a right channel. The apparatus includes a prediction coefficient estimator, downmixer, and multiplexer. The downmixer is configured operate either in a prediction mode or a non-prediction mode.

公开(公告)号：US10297259B2

公开(公告)日：2019-05-21

申请号：US15873083

申请日：2018-01-17

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Kristofer Kjoerling

IPC: H04S3/02 ,  H04S5/00 ,  H04S5/02 ,  G10L19/18 ,  G10L19/002 ,  G10L19/008

Abstract: The application relates to audio encoder and decoder systems. An embodiment of the encoder system comprises a downmix stage for generating a downmix signal and a residual signal based on a stereo signal. In addition, the encoder system comprises a parameter determining stage for determining parametric stereo parameters such as an inter-channel intensity difference and an inter-channel cross-correlation. Preferably, the parametric stereo parameters are time- and frequency-variant. Moreover, the encoder system comprises a transform stage. The transform stage generates a pseudo left/right stereo signal by performing a transform based on the downmix signal and the residual signal. The pseudo stereo signal is processed by a perceptual stereo encoder. For stereo encoding, left/right encoding or mid/side encoding is selectable. Preferably, the selection between left/right stereo encoding and mid/side stereo encoding is time- and frequency-variant.

公开(公告)号：US10283126B2

公开(公告)日：2019-05-07

申请号：US15849622

申请日：2017-12-20

Applicant: DOLBY INTERNATIONAL AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Lars Villemoes

IPC: H04S3/00 ,  G10L19/02 ,  G10L19/008 ,  G10L19/06 ,  G10L19/16 ,  G10L25/12

Abstract: The invention provides methods and devices for stereo encoding and decoding using complex prediction in the frequency domain. In one embodiment, a decoding method, for obtaining an output stereo signal from an input stereo signal encoded by complex prediction coding and comprising first frequency-domain representations of two input channels, comprises the upmixing steps of: (i) computing a second frequency-domain representation of a first input channel; and (ii) computing an output channel on the basis of the first and second frequency-domain representations of the first input channel, the first frequency-domain representation of the second input channel and a complex prediction coefficient. The upmixing can be suspended responsive to control data.

公开(公告)号：US20180144751A1

公开(公告)日：2018-05-24

申请号：US15873083

申请日：2018-01-17

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Kristofer Kjoerling

IPC: G10L19/002 ,  H04S5/00 ,  H04S3/02 ,  G10L19/008 ,  H04S5/02 ,  G10L19/18

CPC classification number: G10L19/002 ,  G10L19/008 ,  G10L19/18 ,  H04S3/02 ,  H04S5/00 ,  H04S5/005 ,  H04S5/02 ,  H04S2400/01 ,  H04S2400/03 ,  H04S2420/03

Abstract: The application relates to audio encoder and decoder systems. An embodiment of the encoder system comprises a downmix stage for generating a downmix signal and a residual signal based on a stereo signal. In addition, the encoder system comprises a parameter determining stage for determining parametric stereo parameters such as an inter-channel intensity difference and an inter-channel cross-correlation. Preferably, the parametric stereo parameters are time- and frequency-variant. Moreover, the encoder system comprises a transform stage. The transform stage generates a pseudo left/right stereo signal by performing a transform based on the downmix signal and the residual signal. The pseudo stereo signal is processed by a perceptual stereo encoder. For stereo encoding, left/right encoding or mid/side encoding is selectable. Preferably, the selection between left/right stereo encoding and mid/side stereo encoding is time- and frequency-variant.

公开(公告)号：US09761233B2

公开(公告)日：2017-09-12

申请号：US15170100

申请日：2016-06-01

Applicant: Dolby International AB

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Lars Villemoes

IPC: G10L19/02 ,  G10L19/16 ,  G10L19/008 ,  G10L19/06 ,  H04S3/00

CPC classification number: G10L19/008 ,  G10L19/0212 ,  G10L19/06 ,  G10L19/167 ,  G10L25/12 ,  H04S3/008 ,  H04S2400/01

Abstract: The invention provides methods and devices for stereo encoding and decoding using complex prediction in the frequency domain. In one embodiment, a decoding method, for obtaining an output stereo signal from an input stereo signal encoded by complex prediction coding and comprising first frequency-domain representations of two input channels, comprises the upmixing steps of: (i) computing a second frequency-domain representation of a first input channel; and (ii) computing an output channel on the basis of the first and second frequency-domain representations of the first input channel, the first frequency-domain representation of the second input channel and a complex prediction coefficient. The method comprises applying independent band-width limits for the input channels.

公开(公告)号：US08655670B2

公开(公告)日：2014-02-18

申请号：US13645700

申请日：2012-10-05

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

Inventor： Heiko Purnhagen ,  Pontus Carlsson ,  Lars Villemoes ,  Julien Robillard ,  Matthias Neusinger ,  Christian Helmrich ,  Johannes Hilpert ,  Nikolaus Rettelbach ,  Sascha Disch ,  Bernd Edler

IPC: G10L19/00

CPC classification number: G10L19/04 ,  G10L19/008

Abstract: An encoder, based on a combination of two audio channels, obtains a first combination signal as a mid-signal and a residual signal derivable using a predicted side signal derived from the mid signal. The first combination signal and the prediction residual signal are encoded and written into a data stream together with the prediction information. A decoder generates decoded first and second channel signals using the prediction residual signal, the first combination signal and the prediction information. A real-to-imaginary transform may be applied for estimating the imaginary part of the spectrum of the first combination signal. For calculating the prediction signal used in the derivation of the prediction residual signal, the real-valued first combination signal is multiplied by a real portion of the complex prediction information and the estimated imaginary part of the first combination signal is multiplied by an imaginary portion of the complex prediction information.

Abstract translation: 基于两个音频通道的组合的编码器获得作为中间信号的第一组合信号和使用从中间信号导出的预测侧信号可导出的残差信号。 将第一组合信号和预测残差信号与预测信息一起编码并写入数据流。 解码器使用预测残差信号，第一组合信号和预测信息来产生解码的第一和第二信道信号。 可以应用实数到虚部的变换来估计第一组合信号的频谱的虚部。 为了计算在推导预测残差信号中使用的预测信号，将实值第一组合信号乘以复数预测信息的实部，并将第一组合信号的估计虚部乘以假想部分 复杂的预测信息。