公开(公告)号：US10424312B2

公开(公告)日：2019-09-24

申请号：US16189797

申请日：2018-11-13

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：US10388292B2

公开(公告)日：2019-08-20

申请号：US16222901

申请日：2018-12-17

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

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

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：US20190214026A1

公开(公告)日：2019-07-11

申请号：US16222901

申请日：2018-12-17

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

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

CPC classification number: G10L19/008 ,  G10L19/24 ,  H04S3/008 ,  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：US10236003B2

公开(公告)日：2019-03-19

申请号：US15319699

申请日：2015-06-22

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 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：US10224044B2

公开(公告)日：2019-03-05

申请号：US15891066

申请日：2018-02-07

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Alexander Krueger ,  Sven Kordon

IPC: H04S3/02 ,  H04S5/02 ,  H04S3/00 ,  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 normalization 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：US10194257B2

公开(公告)日：2019-01-29

申请号：US15320071

申请日：2015-07-02

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Alexander Krueger ,  Sven Kordon

IPC: H04S3/02 ,  H04R3/00 ,  G10L19/008 ,  H04S3/00 ,  G10L19/02

Abstract: Encoding of Higher Order Ambisonics (HOA) signals commonly results in high data rates. For data rate reduction, a method (100) for encoding direction information for frames of an input HOA signal comprises determining (s101) active candidate directions (MDIR(k)) among predefined global directions having global direction indices, dividing (s102) the input HOA signal into frequency subbands (f1 . . . , fF), determining (s103) for each frequency subband active subband directions among the active candidate directions, assigning (s104) a relative direction index to each direction per subband, assembling (s105) direction information for the frame, the direction information comprising the active candidate directions (MDIRk)), for each subband and each active candidate direction a bit indicating whether or not the active candidate direction is an active subband direction for the respective frequency subband, and for each frequency subband the relative direction indices of active subband directions in the second set of subband directions, and transmitting (s106) the assembled direction information.

公开(公告)号：US10165384B2

公开(公告)日：2018-12-25

申请号：US15702471

申请日：2017-09-12

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger

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

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：US10102864B2

公开(公告)日：2018-10-16

申请号：US15508444

申请日：2015-08-19

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Florian Keiler ,  Sven Kordon ,  Alexander Krueger

IPC: G10L19/00 ,  G10L19/02 ,  G10L19/002

Abstract: For an efficient encoding of subband configuration data the first, penultimate and last subband groups are treated differently than the other subband groups. Further, subband group bandwidth difference values are used in the encoding. The number of subband groups NSB is coded using a fixed number of bits representing NSB−1. The bandwidth value BSB[1] of the first subband group is coded using a unary code representing BSB[1]−1. No bandwidth value BSB[g] is coded for the last subband g=NSB. For subband groups g=2, . . . , NSB−2 bandwidth difference values ΔBSB[g]=BSB[g]−BSB[g−1] are coded using a unary code, and the bandwidth difference value ΔBSB[NSB−1] for subband group g=NSB−1 is coded using a fixed number of bits.

公开(公告)号：US20180220248A1

公开(公告)日：2018-08-02

申请号：US15927985

申请日：2018-03-21

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

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

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

CPC classification number: H04S3/008 ,  G10L19/008 ,  G10L19/20 ,  H04H20/89 ,  H04S3/02 ,  H04S2420/11

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：US20180108362A1

公开(公告)日：2018-04-19

申请号：US15713174

申请日：2017-09-22

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Sven Kordon ,  Alexander Krueger ,  Oliver Wuebbolt

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

CPC classification number: G10L19/008 ,  G10L19/24 ,  H04S3/008 ,  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.