公开(公告)号：US20160232912A1

公开(公告)日：2016-08-11

申请号：US15133410

申请日：2016-04-20

Applicant: DOLBY INTERNATIONAL AB

Inventor： Kristofer KJOERLING ,  Per EKSTRAND ,  Holger HOERICH

IPC: G10L19/24 ,  G10L19/02 ,  G10L19/093 ,  G10L19/06 ,  G10L19/028

CPC classification number: G10L19/0208 ,  G10L19/0017 ,  G10L19/0204 ,  G10L19/028 ,  G10L19/06 ,  G10L19/07 ,  G10L19/093 ,  G10L19/167 ,  G10L19/24 ,  G10L19/26 ,  G10L19/265 ,  G10L21/038

Abstract: A method performed in an audio decoder for reconstructing an original audio signal having a lowband portion and a highband portion is disclosed. The method includes receiving an encoded audio signal and extracting reconstruction parameters from the encoded audio signal. The method further includes decoding the encoded audio signal with a core audio decoder to obtain a decoded lowband portion and regenerating the highband portion based at least in part on a cross over frequency and the decoded lowband portion to obtain a regenerated highband portion. The method also includes creating a synthetic sinusoid with a level based at least in part on a spectral envelope value for the particular subband and a noise floor value for the particular subband and adding the synthetic sinusoid to the regenerated highband portion in the particular frequency band specified by the location information. Finally, the method includes combining the lowband portion and the regenerated highband portion to obtain a full bandwidth audio signal.

Abstract translation: 公开了一种在用于重构具有低频带部分和高频带部分的原始音频信号的音频解码器中执行的方法。 该方法包括接收经编码的音频信号并从编码的音频信号中提取重建参数。 该方法还包括用核心音频解码器对编码的音频信号进行解码以获得解码的低频带部分，并且至少部分地基于交叉频率和解码的低频带部分来再生高频部分，以获得再生的高频带部分。 该方法还包括至少部分地基于特定子带的频谱包络值和特定子带的噪声本底值创建具有电平的合成正弦波，并将合成正弦波加到指定的特定频带中的再生高频带部分 通过位置信息。 最后，该方法包括组合低频带部分和再生高频部分以获得全带宽音频信号。

公开(公告)号：US20130238345A1

公开(公告)日：2013-09-12

申请号：US13872930

申请日：2013-04-29

Applicant: DOLBY INTERNATIONAL AB

Inventor： Per EKSTRAND ,  Lars Falck VILLEMOES ,  Heiko PURNHAGEN

IPC: G10L19/008

CPC classification number: G10L19/008 ,  G10L19/0208

Abstract: An apparatus for processing a plurality of real-valued subband signals using a first real-valued subband signal and a second real-valued subband signal to provide at least a complex-valued subband signal comprises a multiband filter for providing an intermediate real-valued subband signal and a calculator for providing the complex-valued subband signal by combining a real-valued subband signal from the plurality of real-valued subband signals and the intermediate subband signal.

Abstract translation: 一种用于使用第一实值子带信号和第二实值子带信号来处理多个实值子带信号以提供至少复值子带信号的装置包括多频带滤波器，用于提供中间实值子带 信号和用于通过组合来自多个实值子带信号和中间子带信号的实值子带信号来提供复值子带信号的计算器。

公开(公告)号：US20250118327A1

公开(公告)日：2025-04-10

申请号：US18982215

申请日：2024-12-16

Applicant: DOLBY INTERNATIONAL AB

Inventor： Kristofer KJOERLING ,  Lars VILLEMOES ,  Heiko PURNHAGEN ,  Per EKSTRAND

IPC: G10L21/0388 ,  G10L19/008 ,  G10L19/02 ,  H04S3/00

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. The high frequency regeneration is performed as a post-processing operation with a delay of 3010 samples per audio channel.

公开(公告)号：US20240105191A1

公开(公告)日：2024-03-28

申请号：US18523067

申请日：2023-11-29

Applicant: DOLBY INTERNATIONAL AB

Inventor： Per EKSTRAND ,  Lars VILLEMOES

IPC: G10L19/022 ,  G10L19/02 ,  G10L19/24 ,  G10L21/038 ,  G10L21/04

CPC classification number: G10L19/022 ,  G10L19/0212 ,  G10L19/24 ,  G10L21/038 ,  G10L21/04

Abstract: The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.

公开(公告)号：US20230217166A1

公开(公告)日：2023-07-06

申请号：US17913156

申请日：2021-03-19

Applicant: Dolby International AB ,  Dolby Laboratories Licensing Corporation

Inventor： Per EKSTRAND ,  Yuxing HAO ,  Xuemei YU

IPC: H04R3/04

CPC classification number: H04R3/04 ,  H04R2430/03 ,  H04R2430/01

Abstract: A method of audio processing includes generating harmonics in a hybrid complex quadrature mirror filter domain. Generating the harmonics may include multiplication, using a feedback delay loop, and dynamic compression. The harmonics may be generated based on one or more hybrid sub-bands of the complex transform domain signal.

公开(公告)号：US20230206935A1

公开(公告)日：2023-06-29

申请号：US18178416

申请日：2023-03-03

Applicant: Dolby International AB

Inventor： Kristofer KJOERLING ,  Lars VILLEMOES ,  Heiko PURNHAGEN ,  Per EKSTRAND

IPC: G10L19/18 ,  G10L21/038

CPC classification number: G10L19/18 ,  G10L21/038

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. The high frequency regeneration is performed as a post-processing operation with a delay of 3010 samples per audio channel.

公开(公告)号：US20230206934A1

公开(公告)日：2023-06-29

申请号：US18178412

申请日：2023-03-03

Applicant: Dolby International AB

Inventor： Kristofer KJOERLING ,  Lars VILLEMOES ,  Heiko PURNHAGEN ,  Per EKSTRAND

IPC: G10L19/18 ,  G10L21/038

CPC classification number: G10L19/18 ,  G10L21/038

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. The high frequency regeneration is performed as a post-processing operation with a delay of 3010 samples per audio channel.

公开(公告)号：US20230206932A1

公开(公告)日：2023-06-29

申请号：US18178396

申请日：2023-03-03

Applicant: Dolby International AB

Inventor： Kristofer KJOERLING ,  Lars VILLEMOES ,  Heiko PURNHAGEN ,  Per EKSTRAND

IPC: G10L19/18 ,  G10L21/038

CPC classification number: G10L19/18 ,  G10L21/038

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. The high frequency regeneration is performed as a post-processing operation with a delay of 3010 samples per audio channel.

公开(公告)号：US20230197089A1

公开(公告)日：2023-06-22

申请号：US18164357

申请日：2023-02-03

Applicant: DOLBY INTERNATIONAL AB

Inventor： Per EKSTRAND ,  Lars VILLEMOES

IPC: G10L19/022 ,  G10L19/02 ,  G10L19/24 ,  G10L21/038 ,  G10L21/04

CPC classification number: G10L19/022 ,  G10L19/24 ,  G10L19/0212 ,  G10L21/04 ,  G10L21/038

Abstract: The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.

公开(公告)号：US20220295347A1

公开(公告)日：2022-09-15

申请号：US17711191

申请日：2022-04-01

Applicant: Dolby International AB

Inventor： Heiko PURNHAGEN ,  Per EKSTRAND

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

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.