公开(公告)号：US11798568B2

公开(公告)日：2023-10-24

申请号：US17392210

申请日：2021-08-02

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Oliver Wuebbolt ,  Johannes Boehm ,  Peter Jax

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

CPC classification number: G10L19/008 ,  H04S3/008 ,  G10L19/167 ,  H04R5/027 ,  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. 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：US11451920B2

公开(公告)日：2022-09-20

申请号：US17189067

申请日：2021-03-01

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Florian Keiler

IPC: H04S7/00 ,  H04S3/00

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：US20220020382A1

公开(公告)日：2022-01-20

申请号：US17392210

申请日：2021-08-02

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Oliver Wuebbolt ,  Johannes Boehm ,  Peter Jax

IPC: G10L19/008 ,  H04S3/00

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：US11217258B2

公开(公告)日：2022-01-04

申请号：US16852459

申请日：2020-04-18

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：US20210258708A1

公开(公告)日：2021-08-19

申请号：US17189067

申请日：2021-03-01

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Florian Keiler

IPC: H04S7/00 ,  H04S3/00

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：US10893372B2

公开(公告)日：2021-01-12

申请号：US16857093

申请日：2020-04-23

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Florian Keiler

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

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：US10827295B2

公开(公告)日：2020-11-03

申请号：US16560733

申请日：2019-09-04

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johannes Boehm ,  Xiaoming Chen

IPC: H04S7/00 ,  H04S5/00 ,  H04S1/00

Abstract: For generating 3D audio content from a two-channel stereo signal, the stereo signal (x(t)) is partitioned into overlapping sample blocks and is transformed into time-frequency domain. From the stereo signal directional and ambient signal components are separated, wherein the estimated directions of the directional components are changed by a predetermined factor, wherein, if changes are within a predetermined interval, they are combined in order to form a directional centre channel object signal. For the other directions an encoding to Higher Order Ambisonics HOA is performed. Additional ambient signal channels are generated by de-correlation and rating by gain factors, followed by encoding to HOA. The directional HOA signals and the ambient HOA signals are combined, and the combined HOA signal and the centre channel object signals are transformed to time domain.

公开(公告)号：US10609501B2

公开(公告)日：2020-03-31

申请号：US16276363

申请日：2019-02-14

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Alexander Krueger ,  Sven Kordon ,  Johannes Boehm

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

Abstract: The invention improves HOA sound field representation compression and decompression. A decoder decodes compressed dominant directional signals and compressed residual component signals so as to provide decompressed dominant directional signals and decompressed time domain signals representing a residual HOA component in a spatial domain. A re-correlator re-correlates the decompressed time domain signals to obtain a corresponding reduced-order residual HOA component. A processor determines a decompressed residual HOA component based on the corresponding reduced-order residual HOA component, and determines predicted directional signals based on at least a parameter. The processor is further configured to determine an HOA sound field representation based on the decompressed dominant directional signals, the predicted directional signals, and the decompressed residual HOA component.

公开(公告)号：US20190259396A1

公开(公告)日：2019-08-22

申请号：US16403224

申请日：2019-05-03

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Oliver Wuebbolt ,  Johannes Boehm ,  Peter Jax

IPC: G10L19/008 ,  H04S3/00

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 firstAmbisonics 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 encoded multi-channel audio data into a second format encoded multi-channel audio data is also provided.

公开(公告)号：US20180220248A1

公开(公告)日：2018-08-02

申请号：US15927985

申请日：2018-03-21

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

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

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