公开(公告)号：US11228856B2

公开(公告)日：2022-01-18

申请号：US17003289

申请日：2020-08-26

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Peter Jax ,  Johannes Boehm ,  William Redmann

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

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.

公开(公告)号：US10986455B2

公开(公告)日：2021-04-20

申请号：US16903238

申请日：2020-06-16

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Florian Keiler ,  Johannes Boehm

IPC: H04S3/02 ,  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：US20200252737A1

公开(公告)日：2020-08-06

申请号：US16789077

申请日：2020-02-12

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：US10595145B2

公开(公告)日：2020-03-17

申请号：US16417515

申请日：2019-05-20

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 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：US10460737B2

公开(公告)日：2019-10-29

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

公开(公告)号：US10448188B2

公开(公告)日：2019-10-15

申请号：US15761351

申请日：2016-09-29

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 center 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 center channel object signals are transformed to time domain.

公开(公告)号：US20190239020A1

公开(公告)日：2019-08-01

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

CPC classification number: H04S7/302 ,  G10L19/008 ,  H04S3/008 ,  H04S2400/01 ,  H04S2420/11

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：US10362424B2

公开(公告)日：2019-07-23

申请号：US15891326

申请日：2018-02-07

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：US10257635B2

公开(公告)日：2019-04-09

申请号：US16019256

申请日：2018-06-26

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Alexander Krueger ,  Sven Kordon ,  Johannes Boehm

IPC: H04R5/00 ,  H04S7/00 ,  G10L19/008 ,  H04S3/00

Abstract: The invention improves HOA sound field representation compression. The HOA representation is analysed for the presence of dominant sound sources and their directions are estimated. Then the HOA representation is decomposed into a number of dominant directional signals and a residual component. This residual component is transformed into the discrete spatial domain in order to obtain general plane wave functions at uniform sampling directions, which are predicted from the dominant directional signals. Finally, the prediction error is transformed back to the HOA domain and represents the residual ambient HOA component for which an order reduction is performed, followed by perceptual encoding of the dominant directional signals and the residual component.

公开(公告)号：US10158959B2

公开(公告)日：2018-12-18

申请号：US15718471

申请日：2017-09-28

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Florian Keiler ,  Johannes Boehm

IPC: H04S3/02 ,  G10L19/008 ,  H04S5/02 ,  H04S3/00 ,  H04S7/00

Abstract: Sound scenes in 3D can be synthesized or captured as a natural sound field. For decoding, a decode matrix is required that is specific for a given loudspeaker setup and is generated using the known loudspeaker positions. However, some source directions are attenuated for 2D loudspeaker setups like e.g. 5.1 surround. An improved method for decoding an encoded audio signal in soundfield format for L loudspeakers at known positions comprises steps of adding (10) a position of at least one virtual loudspeaker to the positions of the L loudspeakers, generating (11) a 3D decode matrix (D′), wherein the positions ({circumflex over (Ω)}1 . . . {circumflex over (Ω)}L) of the L loudspeakers and the at least one virtual position ({circumflex over (Ω)}L+1′) are used, downmixing (12) the 3D decode matrix (D′), and decoding (14) the encoded audio signal (i14) using the downscaled 3D decode matrix ({tilde over (D)}). As a result, a plurality of decoded loudspeaker signals (q14) is obtained.