公开(公告)号：US20180130480A1

公开(公告)日：2018-05-10

申请号：US15563936

申请日：2016-04-01

Applicant: Dolby International AB

Inventor： Heiko PURNHAGEN ,  Per EKSTRAND ,  Harald MUNDT ,  Klaus PEICHL

IPC: G10L19/035 ,  G10L19/02

CPC classification number: G10L19/035 ,  G10L19/0204 ,  G10L21/0316 ,  G10L2019/0002 ,  G10L2019/0004

Abstract: Disclosed are some examples of systems, apparatus, methods and computer program products implementing techniques for extending the range of a set of decoded parameter values for a sequence of frequency bands in an identifiable time frame of an audio signal. In some implementations, the parameter values vary in relation to a sequence of time frames of the audio signal and in relation to a sequence of frequency bands in each time frame. In some implementations, it is determined that a decoded value corresponds to a minimum of a first range of values of a first coding protocol of a set of coding protocols. The determined value is modified to be below the minimum of the first range of values to produce an extended value. A modified set of decoded values including one or more extended values can thus be provided.

公开(公告)号：US20250118326A1

公开(公告)日：2025-04-10

申请号：US18982181

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：US20250118313A1

公开(公告)日：2025-04-10

申请号：US18982254

申请日：2024-12-16

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：US20250029621A1

公开(公告)日：2025-01-23

申请号：US18905649

申请日：2024-10-03

Applicant: DOLBY INTERNATIONAL AB

Inventor： Per EKSTRAND ,  Lars VILLEMOES

IPC: G10L19/022 ,  G10L19/02 ,  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：US20250015785A1

公开(公告)日：2025-01-09

申请号：US18712235

申请日：2022-11-29

Applicant: DOLBY INTERNATIONAL AB

Inventor： Per EKSTRAND

IPC: H03H17/02

Abstract: The present document describes a method (200) for determining N coefficients of an asymmetric prototype filter p0 for use in a low delay M-channel analysis and/or synthesis filter bank (101, 102) comprising M analysis filters hk (103) and/or M synthesis filters fk(106), k=0, . . . , M−1, wherein M is greater than 1, and wherein subband signals which are processed by the analysis and/or synthesis filter bank (101, 102) are decimated by a decimation factor S, with S

公开(公告)号：US20230395089A1

公开(公告)日：2023-12-07

申请号：US18248808

申请日：2021-10-15

Applicant: DOLBY INTERNATIONAL AB

Inventor： Per EKSTRAND ,  Janusz KLESJA ,  Pedro Jafeth VILLASANA TINAJERO ,  Lars VILLEMOES

IPC: G10L21/0208 ,  G10L25/30

CPC classification number: G10L21/0208 ,  G10L25/30

Abstract: A neural network system is provided, implementing a generative model for autoregressively generating a distribution for a plurality of current filter-bank samples of an audio signal, wherein the current samples correspond to a current time slot, and each current sample corresponds to a channel of the filter-bank. The system includes a hierarchy of a plurality of neural network processing tiers ordered from a top to a bottom tier, each tier trained to generate conditioning information based on previous filter-bank samples and, for at least each tier but the top tier, also on the conditioning information from a tier higher up in the hierarchy, and an output stage trained to generate the probability distribution based on previous samples for one or more previous time slots and the conditioning information from the lowest processing tier.

公开(公告)号：US20230197102A1

公开(公告)日：2023-06-22

申请号：US18113397

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 ,  G10L19/008 ,  G10L19/02 ,  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：US20230197101A1

公开(公告)日：2023-06-22

申请号：US18113391

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 ,  G10L19/008 ,  G10L19/02 ,  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：US20230059049A1

公开(公告)日：2023-02-23

申请号：US17973397

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：US20230050996A1

公开(公告)日：2023-02-16

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.