公开(公告)号：US20250095661A1

公开(公告)日：2025-03-20

申请号：US18818367

申请日：2024-08-28

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Florian KEILER ,  Sven KORDON ,  Alexander KRUEGER

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

Abstract: The present invention relates to methods and apparatus for encoding an HOA signal representation (c(t)) of a sound field having an order of N and a number O=(N+1)2 of coefficient sequences to a mezzanine HOA signal representation (wMEZZ(t)). The present invention further relates to methods and apparatus for decoding a reconstructed HOA signal representation from the mezzanine HOA signal representation.

公开(公告)号：US20240040327A1

公开(公告)日：2024-02-01

申请号：US18359198

申请日：2023-07-26

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 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.

公开(公告)号：US20190139555A1

公开(公告)日：2019-05-09

申请号：US16189768

申请日：2018-11-13

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johann-Markus BATKE ,  Florian KEILER ,  Johannes BOEHM

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

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：US20220417690A1

公开(公告)日：2022-12-29

申请号：US17893753

申请日：2022-08-23

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Florian KEILER ,  Johannes BOEHM

IPC: H04S3/02 ,  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：US20200068330A1

公开(公告)日：2020-02-27

申请号：US16660626

申请日：2019-10-22

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes BOEHM ,  Florian KEILER

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

Abstract: A method for performing DRC on a HOA signal comprises transforming the HOA signal to the spatial domain, analyzing the transformed HOA signal, and obtaining, from results of said analyzing, gain factors that are usable for dynamic compression. The gain factors can be transmitted together with the HOA signal. When applying the DRC, the HOA signal is transformed to the spatial domain, the gain factors are extracted and multiplied with the transformed HOA signal in the spatial domain, wherein a gain compensated transformed HOA signal is obtained. The gain compensated transformed HOA signal is transformed back into the HOA domain, wherein a gain compensated HOA signal is obtained. The DRC may be applied in the QMF-filter bank domain.

公开(公告)号：US20190052990A1

公开(公告)日：2019-02-14

申请号：US15891326

申请日：2018-02-07

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes BOEHM ,  Florian KEILER

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

CPC classification number: H04S3/008 ,  G10L19/008 ,  H04S3/02 ,  H04S2420/01 ,  H04S2420/11

Abstract: A method for performing DRC on a HOA signal comprises transforming the HOA signal to the spatial domain, analyzing the transformed HOA signal, and obtaining, from results of said analyzing, gain factors that are usable for dynamic compression. The gain factors can be transmitted together with the HOA signal. When applying the DRC, the HOA signal is transformed to the spatial domain, the gain factors are extracted and multiplied with the transformed HOA signal in the spatial domain, wherein a gain compensated transformed HOA signal is obtained. The gain compensated transformed HOA signal is transformed back into the HOA domain, wherein a gain compensated HOA signal is obtained. The DRC may be applied in the QMF-filter bank domain.

公开(公告)号：US20180308498A1

公开(公告)日：2018-10-25

申请号：US16019233

申请日：2018-06-26

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johann-Markus BATKE ,  Florian KEILER ,  Johannes BOEHM

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

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 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：US20170289725A1

公开(公告)日：2017-10-05

申请号：US15619935

申请日：2017-06-12

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 (D) for the rendering to a given arrangement of target loudspeakers is obtained by steps of obtaining a number (L) of target speakers, their positions (L), positions (S) of a spherical modeling grid and a HOA order (N), generating (141) a mix matrix (G) from the positions (S) of the modeling grid and the positions (L) of the speakers, generating (142) a mode matrix ({tilde over (Ψ)})from the positions (S) of the spherical modeling grid and the HOA order, calculating (143) a first decode matrix ({circumflex over (D)}) from the mix matrix (G) and the mode matrix ({tilde over (Ψ)}), and smoothing and scaling (144, 145) the first decode matrix ({circumflex over (D)}) with smoothing and scaling coefficients.

公开(公告)号：US20240304195A1

公开(公告)日：2024-09-12

申请号：US18607321

申请日：2024-03-15

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johann-Markus BATKE ,  Florian KEILER ,  Johannes BOEHM

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

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 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：US20240056755A1

公开(公告)日：2024-02-15

申请号：US18457030

申请日：2023-08-28

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Florian KEILER ,  Johannes Boehm

IPC: H04S3/02 ,  H04S7/00

CPC classification number: H04S3/02 ,  H04S7/308 ,  H04S2420/11 ,  H04S2400/11 ,  H04S2420/07

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




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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.