公开(公告)号：US20240007813A1

公开(公告)日：2024-01-04

申请号：US18339368

申请日：2023-06-22

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven KORDON ,  Alexander KRUEGER ,  Oliver WUEBBOLT

IPC: H04S3/00 ,  G10L19/008 ,  G10L19/24 ,  H04S7/00

CPC classification number: H04S3/008 ,  G10L19/008 ,  G10L19/24 ,  H04S7/30 ,  H04S2400/01 ,  H04S2420/11

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：US20190356998A1

公开(公告)日：2019-11-21

申请号：US16525074

申请日：2019-07-29

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven KORDON ,  Alexander KRUEGER

IPC: H04S3/00 ,  G10L19/008

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. An aspect of the invention further relates to methods and apparatus decoding multiplexed and perceptually encoded HOA signals, including transforming a vector of PCM encoded spatial domain signals of the HOA representation to a corresponding vector of coefficient domain signals by multiplying the vector of PCM encoded spatial domain signals with a transform matrix and de-normalizing the vector of PCM encoded and normalized coefficient domain signals, wherein said de-normalizing comprises. The methods may include combining a vector of coefficient domain signals and the vector of de-normalized coefficient domain signals to determine a combined vector of HOA coefficient domain signals that can have a variable number of HOA coefficients.

公开(公告)号：US20190214033A1

公开(公告)日：2019-07-11

申请号：US16189797

申请日：2018-11-13

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven KORDON ,  Alexander KRUEGER ,  Oliver WUEBBOLT

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

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

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：US20180166084A1

公开(公告)日：2018-06-14

申请号：US15891066

申请日：2018-02-07

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Alexander KRUEGER ,  Sven KORDON

IPC: G10L19/008 ,  G10L19/24

CPC classification number: G10L19/008 ,  G10L19/24

Abstract: When decompressing 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：US20230179936A1

公开(公告)日：2023-06-08

申请号：US18081956

申请日：2022-12-15

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. An aspect of the invention further relates to methods and apparatus decoding multiplexed and perceptually encoded HOA signals, including transforming a vector of PCM encoded spatial domain signals of the HOA representation to a corresponding vector of coefficient domain signals by multiplying the vector of PCM encoded spatial domain signals with a transform matrix and de-normalizing the vector of PCM encoded and normalized coefficient domain signals, wherein said de-normalizing comprises. The methods may include combining a vector of coefficient domain signals and the vector of de-normalized coefficient domain signals to determine a combined vector of HOA coefficient domain signals that can have a variable number of HOA coefficients.

公开(公告)号：US20220225045A1

公开(公告)日：2022-07-14

申请号：US17711029

申请日：2022-04-01

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven KORDON ,  Alexander KRUEGER

IPC: H04S3/00 ,  G10L19/008

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. An aspect of the invention further relates to methods and apparatus decoding multiplexed and perceptually encoded HOA signals, including transforming a vector of PCM encoded spatial domain signals of the HOA representation to a corresponding vector of coefficient domain signals by multiplying the vector of PCM encoded spatial domain signals with a transform matrix and de-normalizing the vector of PCM encoded and normalized coefficient domain signals, wherein said de-normalizing comprises. The methods may include combining a vector of coefficient domain signals and the vector of de-normalized coefficient domain signals to determine a combined vector of HOA coefficient domain signals that can have a variable number of HOA coefficients.

公开(公告)号：US20220225044A1

公开(公告)日：2022-07-14

申请号：US17700390

申请日：2022-03-21

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven KORDON ,  Alexander KRUEGER

IPC: H04S3/00 ,  G10L19/008

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. The ambient HOA component is represented by a minimum number of HOA coefficient sequences. The remaining channels contain either directional signals or additional coefficient sequences of the ambient HOA component, depending on what will result in optimum perceptual quality. This processing can change on a frame-by-frame basis.

公开(公告)号：US20210144503A1

公开(公告)日：2021-05-13

申请号：US17099120

申请日：2020-11-16

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven KORDON ,  Alexander KRUEGER

IPC: H04S3/00 ,  G10L19/008

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. An aspect of the invention further relates to methods and apparatus decoding multiplexed and perceptually encoded HOA signals, including transforming a vector of PCM encoded spatial domain signals of the HOA representation to a corresponding vector of coefficient domain signals by multiplying the vector of PCM encoded spatial domain signals with a transform matrix and de-normalizing the vector of PCM encoded and normalized coefficient domain signals, wherein said de-normalizing comprises. The methods may include combining a vector of coefficient domain signals and the vector of de-normalized coefficient domain signals to determine a combined vector of HOA coefficient domain signals that can have a variable number of HOA coefficients.

公开(公告)号：US20190174243A1

公开(公告)日：2019-06-06

申请号：US16210957

申请日：2018-12-05

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven KORDON ,  Alexander KRUEGER

IPC: H04S3/02 ,  G10L19/008

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

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)}·0)┐+1)┐.

公开(公告)号：US20180310112A1

公开(公告)日：2018-10-25

申请号：US16019256

申请日：2018-06-26

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. 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.