公开(公告)号：US10075799B2

公开(公告)日：2018-09-11

申请号：US15920849

申请日：2018-03-14

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：US10037762B2

公开(公告)日：2018-07-31

申请号：US15681793

申请日：2017-08-21

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

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

IPC: 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：US09984694B2

公开(公告)日：2018-05-29

申请号：US15417565

申请日：2017-01-27

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Oliver Wuebbolt ,  Johannes Boehm ,  Peter Jax

IPC: G10L19/008 ,  H04S3/00 ,  G10L19/16 ,  H04R5/027

CPC classification number: G10L19/008 ,  G10L19/167 ,  H04R5/027 ,  H04S3/008 ,  H04S2400/01 ,  H04S2400/03 ,  H04S2400/15 ,  H04S2420/03 ,  H04S2420/11

Abstract: Conventional audio compression technologies perform a standardized signal transformation, independent of the type of the content. Multi-channel signals are decomposed into their signal components, subsequently quantized and encoded. This is disadvantageous due to lack of knowledge on the characteristics of scene composition, especially for e.g. multi-channel audio or Higher-Order Ambisonics (HOA) content. An improved method for encoding pre-processed audio data comprises encoding the pre-processed audio data, and encoding auxiliary data that indicate the particular audio pre-processing. An improved method for decoding encoded audio data comprises determining that the encoded audio data had been pre-processed before encoding, decoding the audio data, extracting from received data information about the pre-processing, and post-processing the decoded audio data according to the extracted pre-processing information.

公开(公告)号：US09980073B2

公开(公告)日：2018-05-22

申请号：US15221354

申请日：2016-07-27

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

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

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

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

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：US09838822B2

公开(公告)日：2017-12-05

申请号：US14779326

申请日：2014-03-17

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm

IPC: H04S7/00 ,  G06F17/15 ,  G10L21/02 ,  G10L19/008

CPC classification number: H04S7/30 ,  G06F17/156 ,  G10L19/008 ,  G10L21/02 ,  H04S2400/11 ,  H04S2400/15 ,  H04S2420/11

Abstract: Recordings from microphones that provide 1st order Ambisonics signals, so-called B-format signals, offer a limited cognition of sound directivity. Sound sources are perceived broader than they actually are, especially for off-center listening positions, and the sound sources are often located to be coming from the closest speaker positions. In a method and apparatus for enhancing the directivity of 1st order Ambisonics signals, additional directivity information is extracted (SFA) from the lower order Ambisonics input signal. The additional directivity information is used to estimate higher order Ambisonics coefficients, which are then combined with the coefficients of the input signal. Thus, the directivity of the Ambisonics signal is enhanced, which leads to an increased accuracy of spatial source localization when the Ambisonics signal is decoded to loud speaker signals. The resulting output signal has more energy than the input signal.

公开(公告)号：US09832584B2

公开(公告)日：2017-11-28

申请号：US14761109

申请日：2014-01-09

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Florian Keiler

IPC: H04S3/00 ,  H03G5/00 ,  H03G9/00

CPC classification number: H04S3/008 ,  H03G5/005 ,  H03G9/005 ,  H04S2400/13 ,  H04S2400/15 ,  H04S2420/11

Abstract: The invention relates to Higher-Order Ambisonics (HOA) Content Loudness Level Adjustment. A method for adjusting a loudness level of a HOA audio signal on a transmitting side comprises steps of measuring loudness of only the W-channel of the HOA audio signal, and leveling HOA master gain for all channels of the HOA signal according to the measured loudness of the W-channel.

公开(公告)号：US09767813B2

公开(公告)日：2017-09-19

申请号：US15245061

申请日：2016-08-23

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：US12205600B2

公开(公告)日：2025-01-21

申请号：US18489606

申请日：2023-10-18

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Oliver Wuebbolt ,  Peter Jax ,  Johannes Boehm

IPC: G10L19/008 ,  H04S3/00 ,  G10L19/16 ,  H04R5/027

Abstract: Conventional audio compression technologies perform a standardized signal transformation, independent of the type of the content. Multi-channel signals are decomposed into their signal components, subsequently quantized and encoded. This is disadvantageous due to lack of knowledge on the characteristics of scene composition, especially for e.g. multi-channel audio or Higher-Order Ambisonics (HOA) content. A method for decoding an encoded bitstream of multi-channel audio data and associated metadata is provided, including transforming the first Ambisonics format of the multi-channel audio data to a second Ambisonics format representation of the multi-channel audio data, wherein the transforming maps the first Ambisonics format of the multi-channel audio data into the second Ambisonics format representation of the multi-channel audio data. A method for encoding multi-channel audio data that includes audio data in an Ambisonics format, wherein the encoding includes transforming the audio data in an Ambisonics format into encoded multi-channel audio data is also provided.

公开(公告)号：US11948583B2

公开(公告)日：2024-04-02

申请号：US17560223

申请日：2021-12-22

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

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

IPC: G10L19/00 ,  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：US11895482B2

公开(公告)日：2024-02-06

申请号：US18159135

申请日：2023-01-25

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Peter Jax ,  Johannes Boehm ,  William G. Redmann

IPC: H04S7/00 ,  H04R5/00 ,  G10L19/008

CPC classification number: H04S7/302 ,  G10L19/008 ,  H04R5/00 ,  H04S7/305 ,  H04S2420/11

Abstract: A method for generating loudspeaker signals associated with a target screen size is disclosed. The method includes receiving a bit stream containing encoded higher order ambisonics signals, the encoded higher order ambisonics signals describing a sound field associated with a production screen size. The method further includes decoding the encoded higher order ambisonics signals to obtain a first set of decoded higher order ambisonics signals representing dominant components of the sound field and a second set of decoded higher order ambisonics signals representing ambient components of the sound field. The method also includes combining the first set of decoded higher order ambisonics signals and the second set of decoded higher order ambisonics signals to produce a combined set of decoded higher order ambisonics signals.