公开(公告)号：US10264382B2

公开(公告)日：2019-04-16

申请号：US15876442

申请日：2018-01-22

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven Kordon ,  Alexander Krueger

IPC: H04S3/02 ,  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：US10147437B2

公开(公告)日：2018-12-04

申请号：US15956295

申请日：2018-04-18

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Alexander Krueger ,  Sven Kordon ,  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：US09922657B2

公开(公告)日：2018-03-20

申请号：US15319711

申请日：2015-06-22

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Alexander Krueger ,  Sven Kordon

IPC: H04S5/02 ,  H04S3/00 ,  G10L19/008 ,  G10L19/24

CPC classification number: G10L19/008 ,  G10L19/24

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 normalization of the HOA data frame representation (C(k)). Then the lowest integer number of bits is set to (AA).

公开(公告)号：US09837087B2

公开(公告)日：2017-12-05

申请号：US15275699

申请日：2016-09-26

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Johannes Boehm ,  Sven Kordon ,  Alexander Krueger ,  Peter Jax

IPC: G10L19/012 ,  G10L19/008 ,  G10L19/02 ,  G10L19/038 ,  H04S3/02

CPC classification number: G10L19/012 ,  G10L19/008 ,  G10L19/0212 ,  G10L19/038 ,  H04S3/02 ,  H04S2420/11

Abstract: A method for encoding multi-channel HOA audio signals for noise reduction comprises steps of decorrelating the channels using an inverse adaptive DSHT, the inverse adaptive DSHT comprising a rotation operation and an inverse DSHT, with the rotation operation rotating the spatial sampling grid of the iDSHT, perceptually encoding each of the decorrelated channels, encoding rotation information, the rotation information comprising parameters defining said rotation operation, and transmitting or storing the perceptually encoded audio channels and the encoded rotation information.

公开(公告)号：US12245012B2

公开(公告)日：2025-03-04

申请号：US18487280

申请日：2023-10-16

Applicant: Dolby Laboratories Licensing Corporation

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

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

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：US11875803B2

公开(公告)日：2024-01-16

申请号：US17733757

申请日：2022-04-29

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven Kordon ,  Alexander Krueger

IPC: G10L19/008 ,  H04S7/00

CPC classification number: G10L19/008 ,  H04S7/30 ,  H04S2400/11 ,  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)}·O)┐+1)┐.

公开(公告)号：US11863958B2

公开(公告)日：2024-01-02

申请号：US18081956

申请日：2022-12-15

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger

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

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：US11462222B2

公开(公告)日：2022-10-04

申请号：US16892154

申请日：2020-06-03

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 ^ A ⁢ M ⁢ B , n ⁡ ( k - 1 ) for ⁢ ⁢ n ⁢ ⁢ in ⁢ ⁢ the ⁢ ⁢ first ⁢ ⁢ subset ⁢ c ^ n ⁡ ( k - 1 ) = c ^ P ⁢ S , n ⁡ ( k - 1 ) + c ^ A ⁢ M ⁢ B , 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：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.