公开(公告)号：US10453468B2

公开(公告)日：2019-10-22

申请号：US16269161

申请日：2019-02-06

Applicant: DOLBY INTERNATIONAL AB

Inventor： Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

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

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：US20190189140A1

公开(公告)日：2019-06-20

申请号：US16274044

申请日：2019-02-12

Applicant: Dolby International AB

Inventor： Lars G. Liljeryd ,  Per Ekstrand ,  Fredrik Henn ,  Kristofer Kjoerling

IPC: G10L19/02 ,  G10L21/038 ,  G10L19/26 ,  G10L19/00

CPC classification number: G10L19/0208 ,  G10L19/0017 ,  G10L19/0204 ,  G10L19/26 ,  G10L19/265 ,  G10L21/038

Abstract: The present invention relates to a new method and apparatus for improvement of High Frequency Reconstruction (HFR) techniques using frequency translation or folding or a combination thereof. The proposed invention is applicable to audio source coding systems, and offers significantly reduced computational complexity. This is accomplished by means of frequency translation or folding in the subband domain, preferably integrated with spectral envelope adjustment in the same domain. The concept of dissonance guard-band filtering is further presented. The proposed invention offers a low-complexity, intermediate quality HFR method useful in speech and natural audio coding applications.

公开(公告)号：US20190119753A1

公开(公告)日：2019-04-25

申请号：US16223112

申请日：2018-12-18

Applicant: Dolby International AB

Inventor： Lars Villemoes ,  Per Ekstrand

IPC: C12Q1/6883

CPC classification number: C12Q1/6883 ,  C12Q2600/118 ,  C12Q2600/156 ,  G10L19/0204 ,  G10L19/022 ,  G10L19/265 ,  G10L21/038

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 Q1 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：US10262669B1

公开(公告)日：2019-04-16

申请号：US16208325

申请日：2018-12-03

Applicant: DOLBY INTERNATIONAL AB

Inventor： Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

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

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：US10186280B2

公开(公告)日：2019-01-22

申请号：US15792956

申请日：2017-10-25

Applicant: Dolby International AB

Inventor： Lars Villemoes ,  Per Ekstrand

IPC: G10L21/038 ,  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：US20180322889A1

公开(公告)日：2018-11-08

申请号：US16040243

申请日：2018-07-19

Applicant: DOLBY INTERNATIONAL AB

Inventor： Lars Villemoes ,  Heiko Purnhagen ,  Per Ekstrand

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

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：US10057808B2

公开(公告)日：2018-08-21

申请号：US15584534

申请日：2017-05-02

Applicant: DOLBY INTERNATIONAL AB

Inventor： Heiko Purnhagen ,  Per Ekstrand

IPC: H04W28/06 ,  H04W28/02 ,  G10L19/008 ,  G10L19/035 ,  G10L19/083 ,  H04S1/00 ,  G10L19/038

CPC classification number: H04W28/065 ,  G10L19/008 ,  G10L19/035 ,  G10L19/038 ,  H04S1/007 ,  H04S2420/03 ,  H04W28/0215

Abstract: The present disclosure provides methods, devices and computer program products for non-uniform quantization of parameters relating to parametric spatial coding of audio signals. 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：US10043526B2

公开(公告)日：2018-08-07

申请号：US14881250

申请日：2015-10-13

Applicant: Dolby International AB

Inventor： Per Ekstrand ,  Lars Villemoes

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

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：US09818418B2

公开(公告)日：2017-11-14

申请号：US15452897

申请日：2017-03-08

Applicant: Dolby International AB

Inventor： Kristofer Kjoerling ,  Per Ekstrand ,  Holger Hoerich

IPC: G10L15/00 ,  G10L19/02 ,  G10L19/26 ,  G10L19/07 ,  G10L19/16 ,  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.

公开(公告)号：US09762210B1

公开(公告)日：2017-09-12

申请号：US15608020

申请日：2017-05-30

Applicant: Dolby International AB

Inventor： Per Ekstrand

IPC: G06F7/00 ,  H03H17/02

CPC classification number: H04R3/04 ,  G06F17/10 ,  G06F17/11 ,  G10L19/008 ,  G10L19/0204 ,  G10L19/0208 ,  G10L19/26 ,  G10L19/265 ,  G10L21/00 ,  H03H17/0201 ,  H03H17/0248 ,  H03H17/0266 ,  H03H17/0275 ,  H03H17/0294 ,  H03H2017/0297 ,  H04S7/307

Abstract: An apparatus and method are disclosed for filtering an audio signal. The apparatus includes an analysis filter bank, a phase shifter, a high frequency reconstructor or parametric stereo processor, and a synthesis filter bank. The analysis filterbank receives real-valued time domain input audio samples and generates complex valued subband samples. The phase shifter shifts a phase of the complex-valued subband samples by an amount. The high frequency reconstructor or parametric stereo processor modifies at least some of the complex valued subband samples. A phase shifter then unshifts a phase of the modified complex-valued subband samples by the amount. The synthesis filter bank receives the modified complex valued subband samples and generates time domain output audio samples.