公开(公告)号：US09794713B2

公开(公告)日：2017-10-17

申请号：US15319353

申请日：2015-06-22

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Sven Kordon ,  Alexander Krueger

IPC: H04S5/02 ,  H04S3/00 ,  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 normalization of the HOA data frame representation (C(k)). Then the lowest integer number of bits is set to (AA). β e = ⌈ log 2 ⁡ ( ⌈ log 2 ⁡ ( K MAX · O ) ⌉ + 1 ) ⌉ ( AA )

公开(公告)号：US20170245084A1

公开(公告)日：2017-08-24

申请号：US15588320

申请日：2017-05-05

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：US09691406B2

公开(公告)日：2017-06-27

申请号：US14896383

申请日：2014-05-27

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Peter Jax ,  Alexander Krueger

IPC: G10L19/24 ,  G10L19/008 ,  G10L19/038 ,  H04S3/00

CPC classification number: G10L19/24 ,  G10L19/008 ,  G10L19/038 ,  H04S3/008 ,  H04S2420/11

Abstract: The invention introduces a new concept for hierarchical coding of HOA content. A method for encoding a hierarchical audio bitstream comprises rendering a HOA input signal to surround sound, encoding the surround sound for a base layer output signal, decoding the encoded surround sound to obtain a reconstructed surround sound signal, performing dimensionality reduction on the received HOA input signal, calculating a residual between the dimensionality-reduced HOA signal and the reconstructed surround sound signal, encoding the residual signal, and multiplexing structural information about the HOA input signal, the encoded residuals and the encoded surround sound into a bitstream to obtain a hierarchical audio bitstream.

公开(公告)号：US09668079B2

公开(公告)日：2017-05-30

申请号：US14904406

申请日：2014-06-24

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. 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 normalized and multiplexed with the vector of spatial domain signals.

公开(公告)号：US12245013B2

公开(公告)日：2025-03-04

申请号：US18517301

申请日：2023-11-22

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger

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

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：US20220115027A1

公开(公告)日：2022-04-14

申请号：US17558550

申请日：2021-12-21

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

IPC: G10L19/20 ,  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. 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：US11297455B2

公开(公告)日：2022-04-05

申请号：US17099120

申请日：2020-11-16

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger

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

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：US20210390964A1

公开(公告)日：2021-12-16

申请号：US17353711

申请日：2021-06-21

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Florian Keiler ,  Sven Kordon ,  Alexander Krueger

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

Abstract: The present invention relates to methods and apparatus for encoding an HOA signal representation (c(t)) of a sound field having an order of N and a number O=(N+1)2 of coefficient sequences to a mezzanine HOA signal representation (wMEZZ(t)). The present invention further relates to methods and apparatus for decoding a reconstructed HOA signal representation from the mezzanine HOA signal representation.

公开(公告)号：US10999688B2

公开(公告)日：2021-05-04

申请号：US16841203

申请日：2020-04-06

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：US10779104B2

公开(公告)日：2020-09-15

申请号：US16716424

申请日：2019-12-16

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.