公开(公告)号：US11322165B2

公开(公告)日：2022-05-03

申请号：US17116900

申请日：2020-12-09

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven Kordon ,  Alexander Krueger

IPC: G10L19/008 ,  H04S7/00

Abstract: When compressing an HOA data frame representation, a gain control (15, 151) is applied for each channel signal before it is perceptually encoded (16). The gain values are transferred in a differential manner as side information. However, for starting decoding of such streamed compressed HOA data frame representation absolute gain values are required, which should be coded with a minimum number of bits. For determining such lowest integer number (βe) of bits the HOA data frame representation (C(k)) is rendered in spatial domain to virtual loudspeaker signals lying on a unit sphere, followed by normalisation of the HOA data frame representation (C(k)). Then the lowest integer number of bits is set to βe=┌log2(┌log2(√{square root over (KMAX)}·O)┐+1)┐.

公开(公告)号：US20210058729A1

公开(公告)日：2021-02-25

申请号：US17010827

申请日：2020-09-03

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

IPC: H04S3/00 ,  G10L19/008 ,  G10L19/24

Abstract: A method for compressing a HOA signal being an input HOA representation with input time frames (C(k)) of HOA coefficient sequences comprises spatial HOA encoding of the input time frames and subsequent perceptual encoding and source encoding. Each input time frame is decomposed (802) into a frame of predominant sound signals (XPS(k−1)) and a frame of an ambient HOA component ({tilde over (C)}AMB(k−1)). The ambient HOA component ({tilde over (C)}AMB(k−1)) comprises, in a layered mode, first HOA coefficient sequences of the input HOA representation (cn(k−1)) in lower positions and second HOA coefficient sequences (cAMB,n(k−1)) in remaining higher positions. The second HOA coefficient sequences are part of an HOA representation of a residual between the input HOA representation and the HOA representation of the predominant sound signals.

公开(公告)号：US10714112B2

公开(公告)日：2020-07-14

申请号：US16719806

申请日：2019-12-18

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

IPC: H04R5/00 ,  G10L19/20 ,  G10L19/008 ,  H04S3/00

Abstract: Higher Order Ambisonics represents three-dimensional sound independent of a specific loudspeaker set-up. However, transmission of an HOA representation results in a very high bit rate. Therefore compression with a fixed number of channels is used, in which directional and ambient signal components are processed differently. For coding, portions of the original HOA representation are predicted from the directional signal components. This prediction provides side information which is required for a corresponding decoding. By using some additional specific purpose bits, a known side information coding processing is improved in that the required number of bits for coding that side information is reduced on average.

公开(公告)号：US10679634B2

公开(公告)日：2020-06-09

申请号：US16186765

申请日：2018-11-12

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

IPC: G06F17/00 ,  G10L19/008 ,  H04S3/00 ,  G10L19/24

Abstract: Methods and apparatus for decoding a compressed Higher Order Ambisonics (HOA) representation of a sound or soundfield. The method may include receiving a bit stream containing the compressed HOA representation and decoding, based on a determination that there are multiple layers, the compressed HOA representation from the bitstream to obtain a sequence of decoded HOA representations. A first subset of the sequence of decoded HOA representations is determined based only on corresponding ambient HOA components. A second subset of the sequence of decoded HOA representations is determined based on corresponding ambient HOA components and corresponding predominant sound components. For a frame k, the sequence of decoded HOA representations are represented at least in part by c ^ ~ n ⁡ ( k - 1 ) = { c ^ AMB , n ⁡ ( k - 1 ) for ⁢ ⁢ n ⁢ ⁢ in ⁢ ⁢ the ⁢ ⁢ first ⁢ ⁢ subset c ^ n ⁡ ( k - 1 ) = c ^ PS , n ⁡ ( k - 1 ) + c ^ AMB , n ⁡ ( k - 1 ) , for ⁢ ⁢ n ⁢ ⁢ in ⁢ ⁢ the ⁢ ⁢ second ⁢ ⁢ subset where ĉAMB,n(k−1) corresponds to the corresponding ambient HOA components and ĉPS,n(k−1) corresponds to the corresponding predominant sound components.

公开(公告)号：US10468037B2

公开(公告)日：2019-11-05

申请号：US15747022

申请日：2016-07-29

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Florian Keiler ,  Sven Kordon ,  Alexander Krueger

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

Abstract: From an HOA signal representation (c(t)) of a sound field having an order of N and a number 0=(N+1)2 of coefficient sequences a mezzanine HOA signal representation (wMEZZ(t)) is generated that consists of an arbitrary number I

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：US20190215630A9

公开(公告)日：2019-07-11

申请号：US15790375

申请日：2017-10-23

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger

IPC: H04S3/00 ,  G10L19/008

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

Abstract: There are two representations for Higher Order Ambisonics denoted HOA: spatial domain and coefficient domain. The invention generates from a coefficient domain representation a mixed spatial/coefficient domain representation, wherein the number of said HOA signals can be variable. A vector of coefficient domain signals is separated into a vector of coefficient domain signals having a constant number of HOA coefficients and a vector of coefficient domain signals having a variable number of HOA coefficients. The constant-number HOA coefficients vector is transformed to a corresponding spatial domain signal vector. In order to facilitate high-quality coding, without creating signal discontinuities the variable-number HOA coefficients vector of coefficient domain signals is adaptively normalised and multiplexed with the vector of spatial domain signals.

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：US10257632B2

公开(公告)日：2019-04-09

申请号：US15751255

申请日：2016-03-01

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven Kordon ,  Alexander Krueger

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

Abstract: Higher Order Ambisonics (HOA) signals can be compressed by decomposition into a predominant sound component and a residual ambient component. The compressed representation comprises pre-dominant sound signals, coefficient sequences of the ambient component and side information. For efficiently combining HOA decompression and HOA rendering to obtain loudspeaker signals, combined rendering and decoding of the compressed HOA signal comprises perceptually decoding the perceptually coded portion and decoding the side information, without reconstructing HOA coefficient sequences. For reconstructing components of a first type, fading of coefficient sequences is not required, while for components of a second type fading is required. For each second type component, different linear operations are determined: one for coefficient sequences that in a current frame require no fading, one for those that require fading-in, and one for those that require fading-out. From the perceptually decoded signals of each second type component, faded-in and faded-out versions are generated, to which the respective linear operations are applied.

公开(公告)号：US10127914B2

公开(公告)日：2018-11-13

申请号：US15127545

申请日：2015-03-20

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

IPC: G06F17/00 ,  G10L19/008 ,  H04S3/00 ,  G10L19/24

Abstract: A method for compressing a HOA signal being an input HOA representation with input time frames (C(k)) of HOA coefficient sequences comprises spatial HOA encoding of the input time frames and subsequent perceptual encoding and source encoding. Each input time frame is decomposed (802) into a frame of predominant sound signals (XPS(k−1)) and a frame of an ambient HOA component (CAMB(k−1)). The ambient HOA component (C˜AMB(k−1)) comprises, in a layered mode, first HOA coefficient sequences of the input HOA representation (cn(k−1)) in lower positions and second HOA coefficient sequences (cAMB,n(k−1)) in remaining higher positions. The second HOA coefficient sequences are part of an HOA representation of a residual between the input HOA representation and the HOA representation of the predominant sound signals.