公开(公告)号：US11626123B2

公开(公告)日：2023-04-11

申请号：US17078113

申请日：2020-10-23

Applicant: DOLBY INTERNATIONAL AB

Inventor： Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

IPC: G10L19/00 ,  G10L19/26 ,  G10L19/008 ,  G10L19/24

Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.

公开(公告)号：US11626121B2

公开(公告)日：2023-04-11

申请号：US17973393

申请日：2022-10-25

Applicant: DOLBY INTERNATIONAL AB

Inventor： Kristofer Kjoerling ,  Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

IPC: G10L19/02 ,  G10L19/16 ,  G10L19/26 ,  H03M7/30

Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.

公开(公告)号：US20230042393A1

公开(公告)日：2023-02-09

申请号：US17963767

申请日：2022-10-11

Applicant: DOLBY INTERNATIONAL AB

Inventor： Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

IPC: G10L19/26 ,  G10L19/008 ,  G10L19/24

Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.

公开(公告)号：US20220293115A1

公开(公告)日：2022-09-15

申请号：US17831080

申请日：2022-06-02

Applicant: DOLBY INTERNATIONAL AB

Inventor： Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

IPC: G10L19/16 ,  G10L19/035 ,  G10L19/24 ,  G10L21/038

Abstract: Embodiments relate to an audio processing unit that includes a buffer, bitstream payload deformatter, and a decoding subsystem. The buffer stores at least one block of an encoded audio bitstream. The block includes a fill element that begins with an identifier followed by fill data. The fill data includes at least one flag identifying whether enhanced spectral band replication (eSBR) processing is to be performed on audio content of the block. A corresponding method for decoding an encoded audio bitstream is also provided.

公开(公告)号：US11297533B2

公开(公告)日：2022-04-05

申请号：US16905920

申请日：2020-06-19

Applicant: DOLBY INTERNATIONAL AB

Inventor： Heiko Purnhagen ,  Per Ekstrand

IPC: H04W28/06 ,  H04W28/02 ,  G10L19/008 ,  G10L19/035 ,  G10L19/038 ,  H04S1/00

Abstract: The present disclosure provides methods, devices and computer program products for non-uniform quantization of parameters. The disclosure further relates to a method and apparatus for reconstructing an audio object in an audio decoding system taking the non-uniformly quantized parameters into account. According to the disclosure, such an approach renders it possible to reduce bit consumption without substantially reducing the quality of the reconstructed audio object.

公开(公告)号：US11238876B2

公开(公告)日：2022-02-01

申请号：US16556016

申请日：2019-08-29

Applicant: Dolby International AB

Inventor： Kristofer Kjoerling ,  Per Ekstrand ,  Holger Hoerich

IPC: G10L19/02 ,  G10L21/038 ,  G10L19/07 ,  G10L19/24 ,  G10L19/00 ,  G10L19/028 ,  G10L19/06 ,  G10L19/093 ,  G10L19/26 ,  G10L19/16

Abstract: The present invention proposes a new method and a new apparatus for enhancement of audio source coding systems utilising high frequency reconstruction (HFR). It utilises a detection mechanism on the encoder side to assess what parts of the spectrum will not be correctly reproduced by the HFR method in the decoder. Information on this is efficiently coded and sent to the decoder, where it is combined with the output of the HFR input.

公开(公告)号：US11200874B2

公开(公告)日：2021-12-14

申请号：US16876793

申请日：2020-05-18

Applicant: Dolby International AB

Inventor： Per Ekstrand ,  Lars Villemoes ,  Per Hedelin

IPC: G10L21/038 ,  G10H1/00 ,  G10L19/26 ,  G10H1/12 ,  G10L21/0388

Abstract: The present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. In particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. The system may comprise an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of Δf. The system further comprises a nonlinear processing unit (502) configured to determine a set of synthesis subband signals from the set of analysis subband signals using a transposition order P; wherein the set of synthesis subband signals comprises a portion of the set of analysis subband signals phase shifted by an amount derived from the transposition order P; and a synthesis filter bank (504) configured to generate the high frequency component of the signal from the set of synthesis subband signals; wherein the synthesis filter bank (504) has a frequency resolution of FΔf; with F being a resolution factor, with F≥1; wherein the transposition order P is different from the resolution factor F.

公开(公告)号：US10657937B2

公开(公告)日：2020-05-19

申请号：US16376433

申请日：2019-04-05

Applicant: Dolby International AB

Inventor： Per Ekstrand ,  Lars Villemoes ,  Per Hedelin

IPC: G10H1/00 ,  G10L21/038 ,  G10L19/26 ,  G10H1/12 ,  G10L21/0388

Abstract: The present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. In particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. The system may comprise an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of Δf. The system further comprises a nonlinear processing unit (502) configured to determine a set of synthesis subband signals from the set of analysis subband signals using a transposition order P; wherein the set of synthesis subband signals comprises a portion of the set of analysis subband signals phase shifted by an amount derived from the transposition order P; and a synthesis filter bank (504) configured to generate the high frequency component of the signal from the set of synthesis subband signals; wherein the synthesis filter bank (504) has a frequency resolution of FΔf; with F being a resolution factor, with F≥1; wherein the transposition order P is different from the resolution factor F.

公开(公告)号：US10584386B2

公开(公告)日：2020-03-10

申请号：US16223112

申请日：2018-12-18

Applicant: Dolby International AB

Inventor： Lars Villemoes ,  Per Ekstrand

IPC: G10L21/038 ,  C12Q1/6883 ,  G10L19/26 ,  G10L19/02 ,  G10L19/022

Abstract: The present invention relates to coding of audio signals, and in particular to high frequency reconstruction methods including a frequency domain harmonic transposer. A system and method for generating a high frequency component of a signal from a low frequency component of the signal is described. The system comprises an analysis filter bank (501) comprising an analysis transformation unit (601) having a frequency resolution of Δf; and an analysis window (611) having a duration of DA; the analysis filter bank (501) being configured to provide a set of analysis subband signals from the low frequency component of the signal; a nonlinear processing unit (502, 650) configured to determine a set of synthesis subband signals based on a portion of the set of analysis subband signals, wherein the portion of the set of analysis subband signals is phase shifted by a transposition order T; and a synthesis filter bank (504) comprising a synthesis transformation unit (602) having a frequency resolution of QΔf; and a synthesis window (612) having a duration of DS; the synthesis filter bank (504) being configured to generate the high frequency component of the signal from the set of synthesis subband signals; wherein Q is a frequency resolution factor with Q≥1 and smaller than the transposition order T; and wherein the value of the product of the frequency resolution Δf and the duration DA of the analysis filter bank is selected based on the frequency resolution factor Q.

公开(公告)号：US20190385624A1

公开(公告)日：2019-12-19

申请号：US16556016

申请日：2019-08-29

Applicant: Dolby International AB

Inventor： Kristofer Kjoerling ,  Per Ekstrand ,  Holger Hoerich

IPC: G10L19/02 ,  G10L19/00 ,  G10L19/028 ,  G10L19/06 ,  G10L21/038 ,  G10L19/093 ,  G10L19/16 ,  G10L19/24 ,  G10L19/26 ,  G10L19/07

Abstract: The present invention proposes a new method and a new apparatus for enhancement of audio source coding systems utilising high frequency reconstruction (HFR). It utilises a detection mechanism on the encoder side to assess what parts of the spectrum will not be correctly reproduced by the HFR method in the decoder. Information on this is efficiently coded and sent to the decoder, where it is combined with the output of the HFR input.