公开(公告)号：US11081117B2

公开(公告)日：2021-08-03

申请号：US16580738

申请日：2019-09-24

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Oliver Wuebbolt ,  Johannes Boehm ,  Peter Jax

IPC: G10L19/008 ,  H04S3/00 ,  H04R5/027 ,  G10L19/16

Abstract: Conventional audio compression technologies perform a standardized signal transformation, independent of the type of the content. Multi-channel signals are decomposed into their signal components, subsequently quantized and encoded. This is disadvantageous due to lack of knowledge on the characteristics of scene composition, especially for e.g. multi-channel audio or Higher-Order Ambisonics (HOA) content. A method for decoding an encoded bitstream of multi-channel audio data and associated metadata is provided, including transforming the first Ambisonics format of the multi-channel audio data to a second Ambisonics format representation of the multi-channel audio data, wherein the transforming maps the first Ambisonics format of the multi-channel audio data into the second Ambisonics format representation of the multi-channel audio data. A method for encoding multi-channel audio data that includes audio data in an Ambisonics format, wherein the encoding includes transforming the audio data in an Ambisonics format into encoded multi-channel audio data is also provided.

公开(公告)号：US10600425B2

公开(公告)日：2020-03-24

申请号：US15771084

申请日：2016-11-16

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johannes Boehm ,  Xiaoming Chen

IPC: G10L19/008 ,  H04S3/00

Abstract: A system for converting a channel-based 3D audio signal to a higher-order Ambisonics HOA audio signal, the channel-based 3D audio signal is transformed from time domain to frequency domain. A primary ambient decomposition is carried out for three-channel triplets of blocks of the domain channel-based 3D audio signal, wherein directional signals and ambient signals are provided for each triplet. From the directional signals directional information of a total directional signal for each triple is derived. That total directional signal is HOA encoded according to the derived directions, and ambient signals are HOA encoded according to channel positions. The HOA coefficients of the HOA encoded directional signal and the HOA coefficients of the HOA encoded ambient signal are superimposed in order to obtain a HOA coefficients signal for the channel-based 3D audio signal, followed by a transformation into time domain.

公开(公告)号：US20200020344A1

公开(公告)日：2020-01-16

申请号：US16580738

申请日：2019-09-24

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Oliver Wuebbolt ,  Johannes Boehm ,  Peter Jax

IPC: G10L19/008 ,  H04S3/00

Abstract: Conventional audio compression technologies perform a standardized signal transformation, independent of the type of the content. Multi-channel signals are decomposed into their signal components, subsequently quantized and encoded. This is disadvantageous due to lack of knowledge on the characteristics of scene composition, especially for e.g. multi-channel audio or Higher-Order Ambisonics (HOA) content. A method for decoding an encoded bitstream of multi-channel audio data and associated metadata is provided, including transforming the first Ambisonics format of the multi-channel audio data to a second Ambisonics format representation of the multi-channel audio data, wherein the transforming maps the first Ambisonics format of the multi-channel audio data into the second Ambisonics format representation of the multi-channel audio data. A method for encoding multi-channel audio data that includes audio data in an Ambisonics format, wherein the encoding includes transforming the audio data in an Ambisonics format into encoded multi-channel audio data is also provided.

公开(公告)号：US10522159B2

公开(公告)日：2019-12-31

申请号：US16514446

申请日：2019-07-17

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johann-Markus Batke ,  Florian Keiler ,  Johannes Boehm

IPC: G10L19/008 ,  H04S7/00 ,  H04S3/02

Abstract: Soundfield signals such as e.g. Ambisonics carry a representation of a desired sound field. Methods and apparatus for improved decoding an audio soundfield representation for audio playback comprise receiving, by a processor configured to decode the audio soundfield representation, the audio soundfield representation, receiving, by the processor, a decode matrix for decoding the audio soundfield representation to determine a decoded audio signal. The decode matrix is based on an inverse of a mode matrix, and the coefficients of the mode matrix relate to information for a panning based on positions of loudspeakers over a unit sphere. The mode matrix is further based on an order N. The decoded audio signal is determined based on a multiplication of the decode matrix and the audio soundfield representation.

公开(公告)号：US10390164B2

公开(公告)日：2019-08-20

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: G10L19/00 ,  H04S3/00 ,  G10L19/008 ,  H04H20/89 ,  G10L19/20 ,  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：US10341802B2

公开(公告)日：2019-07-02

申请号：US15768695

申请日：2016-11-11

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Alexander Krueger ,  Johannes Boehm ,  Sven Kordon ,  Xiaoming Chen ,  Stefan Abeling ,  Florian Keiler ,  Holger Kropp

IPC: H04S7/00 ,  H04S3/00

Abstract: Currently there is no simple and satisfying way to create 3D audio from existing 2D content. The conversion from 2D to 3D sound should spatially redistribute the sound from existing channels. From a multi-channel 2D audio input signal (x(k)(t)) a 3D sound representation is generated which includes an HOA representation Formula (I) and channel object signals Formula (II) scaled from channels of the 2D audio input signal. Additional signals Formula (III) placed in the 3D space are generated by scaling (21, 222; 41, 422; Formula (IV)) channels from the 2D audio input signal and by decorrelating (24, 25; 44, 45, 451; Formula (V)) a scaled version of a mix of channels from the 2D audio input signal, whereby spatial positions for the additional signals are predetermined. The additional signals Formula (III) are converted (27; 47) to a HOA representation Formula (I).

公开(公告)号：US10299062B2

公开(公告)日：2019-05-21

申请号：US15220766

申请日：2016-07-27

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Peter Jax ,  Johannes Boehm ,  William Redmann

IPC: H04S3/02 ,  H04S7/00 ,  H04R5/00 ,  G10L19/008

Abstract: A method for generating loudspeaker signals associated with a target screen size is disclosed. The method includes receiving a bit stream containing encoded higher order ambisonics signals, the encoded higher order ambisonics signals describing a sound field associated with a production screen size. The method further includes decoding the encoded higher order ambisonics signals to obtain a first set of decoded higher order ambisonics signals representing dominant components of the sound field and a second set of decoded higher order ambisonics signals representing ambient components of the sound field. The method also includes combining the first set of decoded higher order ambisonics signals and the second set of decoded higher order ambisonics signals to produce a combined set of decoded higher order ambisonics signals.

公开(公告)号：US10134405B2

公开(公告)日：2018-11-20

申请号：US16019233

申请日：2018-06-26

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Johann-Markus Batke ,  Florian Keiler ,  Johannes Boehm

IPC: G10L19/008 ,  H04S3/02 ,  H04S7/00

Abstract: Soundfield signals such as e.g. Ambisonics carry a representation of a desired sound field. The Ambisonics format is based on spherical harmonic decomposition of the soundfield, and Higher Order Ambisonics (HOA) uses spherical harmonics of at least 2nd order. However, commonly used loudspeaker setups are irregular and lead to problems in decoder design. A method for improved decoding an audio soundfield representation for audio playback comprises calculating a panning function (W) using a geometrical method based on the positions of a plurality of loudspeakers and a plurality of source directions, calculating a mode matrix (Ξ) from the loudspeaker positions, calculating a pseudo-inverse mode matrix (Ξ+) and decoding the audio soundfield representation. The decoding is based on a decode matrix (D) that is obtained from the panning function (W) and the pseudo-inverse mode matrix (Ξ+).

公开(公告)号：US10038965B2

公开(公告)日：2018-07-31

申请号：US15435175

申请日：2017-02-16

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Alexander Krueger ,  Sven Kordon ,  Johannes Boehm

IPC: H04R5/00 ,  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 analyzed 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：US09646618B2

公开(公告)日：2017-05-09

申请号：US14651313

申请日：2013-12-04

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Alexander Krueger ,  Sven Kordon ,  Johannes Boehm

IPC: 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 analyzed 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.