公开(公告)号：US10304469B2

公开(公告)日：2019-05-28

申请号：US15685252

申请日：2017-08-24

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johannes Boehm ,  Sven Kordon ,  Alexander Krüger ,  Peter Jax

IPC: H04S3/02 ,  G10L19/02 ,  G10L19/008 ,  G10L19/012 ,  G10L19/038

Abstract: A method for encoding multi-channel HOA audio signals for noise reduction comprises steps of decorrelating the channels using an inverse adaptive DSHT, the inverse adaptive DSHT comprising a rotation operation and an inverse DSHT, with the rotation operation rotating the spatial sampling grid of the iDSHT, perceptually encoding each of the decorrelated channels, encoding rotation information, the rotation information comprising parameters defining said rotation operation, and transmitting or storing the perceptually encoded audio channels and the encoded rotation information.

公开(公告)号：US10091601B2

公开(公告)日：2018-10-02

申请号：US15457718

申请日：2017-03-13

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm

IPC: H04S3/02 ,  H04S7/00

Abstract: Multi-channel audio content is mixed for a particular loudspeaker setup. However, a consumer's audio setup is very likely to use a different placement of speakers. The present invention provides a method of rendering multi-channel audio that assures replay of the spatial signal components with equal loudness of the signal. A method for obtaining an energy preserving mixing matrix (G) for mixing L1 input audio channels to L2 output channels comprises steps of obtaining a first mixing matrix Ĝ, performing a singular value decomposition on the first mixing matrix Ĝ to obtain a singularity matrix S, processing the singularity matrix S to obtain a processed singularity matrix Ŝ, determining a scaling factor a, and calculating an improved mixing matrix G according to G=aUŜVT. The perceived sound, loudness, timbre and spatial impression of multi-channel audio replayed on an arbitrary loudspeaker setup practically equals that of the original speaker setup.

公开(公告)号：US09837087B2

公开(公告)日：2017-12-05

申请号：US15275699

申请日：2016-09-26

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Sven Kordon ,  Alexander Krueger ,  Peter Jax

IPC: G10L19/012 ,  G10L19/008 ,  G10L19/02 ,  G10L19/038 ,  H04S3/02

CPC classification number: G10L19/012 ,  G10L19/008 ,  G10L19/0212 ,  G10L19/038 ,  H04S3/02 ,  H04S2420/11

Abstract: A method for encoding multi-channel HOA audio signals for noise reduction comprises steps of decorrelating the channels using an inverse adaptive DSHT, the inverse adaptive DSHT comprising a rotation operation and an inverse DSHT, with the rotation operation rotating the spatial sampling grid of the iDSHT, perceptually encoding each of the decorrelated channels, encoding rotation information, the rotation information comprising parameters defining said rotation operation, and transmitting or storing the perceptually encoded audio channels and the encoded rotation information.

公开(公告)号：US09712938B2

公开(公告)日：2017-07-18

申请号：US14415561

申请日：2013-07-16

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Florian Keiler

IPC: H04S7/00 ,  H04S3/00

CPC classification number: H04S7/30 ,  H04S3/008 ,  H04S2420/11

Abstract: The invention discloses rendering sound field signals, such as Higher-Order Ambisonics (HOA), for arbitrary loudspeaker setups, where the rendering results in highly improved localization properties and is energy preserving. This is obtained by a new type of decode matrix for sound field data, and a new way to obtain the decode matrix. In a method for rendering an audio sound field representation for arbitrary spatial loudspeaker setups, the decode matrix for the rendering to a given arrangement of target loudspeakers is obtained by steps of obtaining a number of target speakers, their positions, positions of a spherical modeling grid and a HOA order, generating a mix matrix from the positions of the modeling grid and the positions of the speakers, generating a mode matrix from the positions of the spherical modeling grid and the HOA order, calculating a first decode matrix from the mix matrix and the mode matrix, and smoothing and scaling the first decode matrix with smoothing and scaling coefficients.

公开(公告)号：US09460726B2

公开(公告)日：2016-10-04

申请号：US14750115

申请日：2015-06-25

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johann-Markus Batke ,  Florian Keiler ,  Johannes Boehm

IPC: G10L19/008 ,  H04S3/02

CPC classification number: G10L19/008 ,  H04S3/02 ,  H04S7/308 ,  H04S2400/13 ,  H04S2420/11

Abstract: Soundfield signals such as e.g. Ambisonics carry a representation of a desired sound field. The Ambisonics format is based on spherical harmonic decomposition of the soundfield, and Higher Order Ambisonics (HOA) uses spherical harmonics of at least 2nd order. However, commonly used loudspeaker setups are irregular and lead to problems in decoder design. A method for improved decoding an audio soundfield representation for audio playback comprises calculating (110) a function (W) using a geometrical method based on the positions of a plurality of loudspeakers and a plurality of source directions, calculating (120) a mode matrix (Ξ) from the loudspeaker positions, calculating (130) a pseudo-inverse mode matrix (Ξ+) and decoding (140) the audio soundfield representation. The decoding is based on a decode matrix (D) that is obtained from the function (W) and the pseudo-inverse mode matrix (Ξ+).

Abstract translation: Soundfield信号，例如 Ambisonics携带所需声场的表示。 Ambisonics格式基于声场的球谐函数分解，而高阶Ambisonics（HOA）使用至少二阶的球谐函数。 然而，常用的扬声器设置是不规则的，并导致解码器设计中的问题。 一种用于改进对用于音频回放的音频声场表示进行解码的方法包括使用基于多个扬声器和多个源方向的位置的几何方法来计算（110）功能（W），计算（120）模式矩阵 Ξ）从扬声器位置，计算（130）伪逆模式矩阵（Ξ+）和解码（140）音频声场表示。 解码基于从函数（W）和伪逆模式矩阵（Ξ+）获得的解码矩阵（D）。

公开(公告)号：US09454971B2

公开(公告)日：2016-09-27

申请号：US14400039

申请日：2013-05-06

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Alexander Kruger ,  Sven Kordon ,  Johannes Boehm ,  Johann-Markus Batke

IPC: H04R5/00 ,  G10L19/008 ,  H04S3/00 ,  H04H20/89 ,  H04S3/02

CPC classification number: H04S3/008 ,  G10L19/008 ,  G10L19/20 ,  H04H20/89 ,  H04S3/02 ,  H04S2420/11

Abstract: Higher Order Ambisonics (HOA) represents a complete sound field in the vicinity of a sweet spot, independent of loudspeaker set-up. The high spatial resolution requires a high number of HOA coefficients. In the invention, dominant sound directions are estimated and the HOA signal representation is decomposed into dominant directional signals in time domain and related direction information, and an ambient component in HOA domain, followed by compression of the ambient component by reducing its order. The reduced-order ambient component is transformed to the spatial domain, and is perceptually coded together with the directional signals. At receiver side, the encoded directional signals and the order-reduced encoded ambient component are perceptually decompressed, the perceptually decompressed ambient signals are transformed to an HOA domain representation of reduced order, followed by order extension. The total HOA representation is recomposed from the directional signals, the corresponding direction information, and the original-order ambient HOA component.

Abstract translation: 高阶Ambisonics（HOA）代表一个完美的声场，位于甜蜜点附近，独立于扬声器设置。 高空间分辨率需要大量的HOA系数。 在本发明中，主要声音方向被估计，并且HOA信号表示被分解成时域中的主要方向信号和相关方向信息，以及HOA域中的环境分量，随后通过降低其顺序来压缩环境分量。 将低阶环境分量变换为空间域，并与定向信号一起被感知地编码。 在接收机侧，编码的定向信号和降序编码的环境分量被感知地解压缩，感知解压缩的环境信号被转换为降序的HOA域表示，随后是顺序扩展。 总的HOA表示由方向信号，相应的方向信息和原始阶环境HOA分量重组。

公开(公告)号：US12283279B2

公开(公告)日：2025-04-22

申请号：US18607321

申请日：2024-03-15

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johann-Markus Batke ,  Florian Keiler ,  Johannes Boehm

IPC: G10L19/00 ,  G10L19/008 ,  H04S3/02 ,  H04S7/00

Abstract: Soundfield signals such as e.g. Ambisonics carry a representation of a desired sound field. The Ambisonics format is based on spherical harmonic decomposition of the soundfield, and Higher Order Ambisonics (HOA) uses spherical harmonics of at least 2nd order. However, commonly used loudspeaker setups are irregular and lead to problems in decoder design. A method for improved decoding an audio soundfield representation for audio playback comprises calculating a panning function (W) using a geometrical method based on the positions of a plurality of loudspeakers and a plurality of source directions, calculating a mode matrix (Ξ) from the loudspeaker positions, calculating a pseudo-inverse mode matrix (Ξ+) and decoding the audio soundfield representation. The decoding is based on a decode matrix (D) that is obtained from the panning function (W) and the pseudo-inverse mode matrix (Ξ+).

公开(公告)号：US12245014B2

公开(公告)日：2025-03-04

申请号：US18457030

申请日：2023-08-28

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Florian Keiler ,  Johannes Boehm

IPC: H04S3/02 ,  H04R5/00 ,  H04R5/02 ,  H04S5/02 ,  H04S7/00

Abstract: Improved methods and/or apparatus for decoding an encoded audio signal in soundfield format for L loudspeakers. The method and/or apparatus can render an Ambisonics format audio signal to 2D loudspeaker setup(s) based on a rendering matrix. The rendering matrix has elements based on loudspeaker positions and wherein the rendering matrix is determined based on weighting at least an element of a first matrix with a weighting factor ℊ = 1 L . The first matrix is determined based on positions of the L loudspeakers and at least a virtual position of at least a virtual loudspeaker that is added to the positions of the L loudspeakers.

公开(公告)号：US12245012B2

公开(公告)日：2025-03-04

申请号：US18487280

申请日：2023-10-16

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Alexander Krueger ,  Sven Kordon ,  Johannes Boehm ,  Johann-Markus Batke

IPC: H04S3/00 ,  G10L19/008 ,  G10L19/20 ,  H04H20/89 ,  H04S3/02

Abstract: A method and apparatus for decompressing a Higher Order Ambisonics (HOA) signal representation is disclosed. The apparatus includes an input interface that receives an encoded directional signal and an encoded ambient signal and an audio decoder that perceptually decodes the encoded directional signal and encoded ambient signal to produce a decoded directional signal and a decoded ambient signal, respectively. The apparatus further includes an extractor for obtaining side information related to the directional signal and an inverse transformer for converting the decoded ambient signal from a spatial domain to an HOA domain representation of the ambient signal. The apparatus also includes a synthesizer for recomposing a Higher Order Ambisonics (HOA) signal from the HOA domain representation of the ambient signal and the decoded directional signal. The side information includes a direction of the directional signal selected from a set of uniformly spaced directions.

公开(公告)号：US11743669B2

公开(公告)日：2023-08-29

申请号：US17943965

申请日：2022-09-13

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Florian Keiler

IPC: H04S7/00 ,  H04S3/00

CPC classification number: H04S7/30 ,  H04S3/008 ,  H04S2420/11

Abstract: The invention discloses rendering sound field signals, such as Higher-Order Ambisonics (HOA), for arbitrary loudspeaker setups, where the rendering results in highly improved localization properties and is energy preserving. This is obtained by rendering an audio sound field representation for arbitrary spatial loudspeaker setups and/or by a decoder that decodes based on a decode matrix (D). The decode matrix (D) is based on smoothing and scaling of a first decode matrix {circumflex over (D)} with smoothing coefficients. The first decode matrix {circumflex over (D)} is based on a mix matrix G and a mode matrix {tilde over (Ψ)}, where the mix matrix G was determined based on L speakers and positions of a spherical modelling grid related to a HOA order N, and the mode matrix {tilde over (Ψ)} was determined based on the spherical modelling grid and the HOA order N.