公开(公告)号：US20250118325A1

公开(公告)日：2025-04-10

申请号：US18982152

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：US20240018844A1

公开(公告)日：2024-01-18

申请号：US18355168

申请日：2023-07-19

Applicant: DOLBY LABORATORIES LICENSING CORPORATION ,  DOLBY INTERNATIONAL AB

Inventor： Jeffrey RIEDMILLER ,  Karl J. ROEDEN ,  Kristofer KJOERLING ,  Heiko PURNHAGEN ,  Vinay MELKOTE ,  Leif SEHLSTROM

IPC: E21B33/138 ,  E21B41/00 ,  E21B21/00 ,  G10L19/008 ,  G10L19/16 ,  G10L19/18 ,  G10L19/24

CPC classification number: E21B33/138 ,  E21B41/00 ,  E21B21/003 ,  G10L19/008 ,  G10L19/167 ,  G10L19/18 ,  G10L19/24

Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (a) from the bitstream, where 1≤m

公开(公告)号：US20230245667A1

公开(公告)日：2023-08-03

申请号：US18295701

申请日：2023-04-04

Applicant: DOLBY INTERNATIONAL AB

Inventor： Heiko PURNHAGEN ,  Kristofer KJOERLING

IPC: G10L19/06 ,  G10L19/02 ,  G10L19/008 ,  G10L25/06 ,  H04S1/00 ,  G10L19/16

CPC classification number: G10L19/06 ,  G10L19/02 ,  G10L19/008 ,  G10L25/06 ,  H04S1/007 ,  G10L19/0204 ,  G10L19/167 ,  H04S2400/03 ,  H04S2420/03 ,  G10L19/0212 ,  G10L19/265

Abstract: The present disclosure provides methods, devices and computer program products for encoding and decoding a stereo audio signal based on an input signal. According to the disclosure, a hybrid approach of using both parametric stereo coding and a discrete representation of the stereo audio signal is used which may improve the quality of the encoded and decoded audio for certain bitrates.

公开(公告)号：US20230197103A1

公开(公告)日：2023-06-22

申请号：US18113406

申请日：2023-02-23

Applicant: Dolby International AB

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

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

CPC classification number: G10L21/0388 ,  G10L19/02 ,  G10L19/008 ,  H04S3/008

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：US20230162748A1

公开(公告)日：2023-05-25

申请号：US18157644

申请日：2023-01-20

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：US20230087552A1

公开(公告)日：2023-03-23

申请号：US17987545

申请日：2022-11-15

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：US20220101865A1

公开(公告)日：2022-03-31

申请号：US17495184

申请日：2021-10-06

Applicant: Dolby International AB

Inventor： Kristofer KJOERLING ,  Robin THESING ,  Harald MUNDT ,  Heiko PURNHAGEN ,  Karl Jonas ROEDEN

IPC: G10L19/02 ,  G10L21/038 ,  G10L21/0388 ,  G10L19/26

Abstract: There is provided methods and apparatuses for decoding and encoding of audio signals. In particular, a method for decoding includes receiving a waveform-coded signal having a spectral content corresponding to a subset of the frequency range above a cross-over frequency. The waveform-coded signal is interleaved with a parametric high frequency reconstruction of the audio signal above the cross-over frequency. In this way an improved reconstruction of the high frequency bands of the audio signal is achieved.

公开(公告)号：US20220059110A1

公开(公告)日：2022-02-24

申请号：US17463192

申请日：2021-08-31

Applicant: DOLBY INTERNATIONAL AB

Inventor： Kristofer KJOERLING ,  Heiko PURNHAGEN ,  Harald MUNDT ,  Karl Jonas ROEDEN ,  Leif SEHLSTROM

IPC: G10L19/20 ,  G10L19/008 ,  G10L25/18 ,  H04S3/00 ,  G10L19/02 ,  G10L19/16

Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.

公开(公告)号：US20210151062A1

公开(公告)日：2021-05-20

申请号：US17050664

申请日：2019-04-25

Applicant: Dolby International AB

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

IPC: 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：US20200380999A1

公开(公告)日：2020-12-03

申请号：US16900950

申请日：2020-06-14

Applicant: DOLBY INTERNATIONAL AB

Inventor： Kristofer KJOERLING ,  Lars VILLEMOES

IPC: G10L19/02 ,  G10L25/18 ,  G10L25/48 ,  H03H17/02 ,  G10L19/00 ,  G10L19/12 ,  G10L19/26 ,  G10L25/21 ,  G10L19/025 ,  G10L19/083 ,  G10L25/12

Abstract: The present invention proposes a new method for improving the performance of a real-valued filterbank based spectral envelope adjuster. By adaptively locking the gain values for adjacent channels dependent on the sign of the channels, as defined in the application, reduced aliasing is achieved. Furthermore, the grouping of the channels during gain-calculation, gives an improved energy estimate of the real valued subband signals in the filterbank.