公开(公告)号：US09318127B2

公开(公告)日：2016-04-19

申请号：US13604313

申请日：2012-09-05

Applicant: Sascha Disch ,  Frederik Nagel ,  Stephan Wilde ,  Lars Villemoes ,  Per Ekstrand

Inventor： Sascha Disch ,  Frederik Nagel ,  Stephan Wilde ,  Lars Villemoes ,  Per Ekstrand

IPC: G10L21/038

CPC classification number: G10L19/0208 ,  G10L19/022 ,  G10L19/16 ,  G10L19/26 ,  G10L21/038

Abstract: An apparatus for generating a bandwidth extended audio signal from an input signal, includes a patch generator for generating one or more patch signals from the input signal, wherein the patch generator is configured for performing a time stretching of subband signals from an analysis filterbank, and wherein the patch generator further includes a phase adjuster for adjusting phases of the subband signals using a filterbank-channel dependent phase correction.

Abstract translation: 一种用于从输入信号产生带宽扩展音频信号的装置，包括用于从所述输入信号产生一个或多个贴片信号的贴片发生器，其中所述贴片发生器被配置为执行来自分析滤波器组的子带信号的时间拉伸，以及 其中所述补丁发生器还包括相位调整器，用于使用滤波器组信道相关相位校正来调整所述子带信号的相位。

公开(公告)号：US08447621B2

公开(公告)日：2013-05-21

申请号：US13206440

申请日：2011-08-09

Applicant: Kristofer Kjörling ,  Per Ekstrand ,  Holger Hörich

Inventor： Kristofer Kjörling ,  Per Ekstrand ,  Holger Hörich

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

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: The present invention proposes a new method and a new apparatus for enhancement of audio source coding systems utilizing high frequency reconstruction (HFR). It utilizes 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 unit.

Abstract translation: 本发明提出了一种利用高频重构（HFR）来增强音频源编码系统的新方法和新装置。 它利用编码器侧的检测机制来评估解码器中HFR方法将不能正确地再现频谱的哪些部分。 关于此的信息被有效地编码并发送到解码器，其中它与HFR单元的输出组合。

公开(公告)号：US08255233B2

公开(公告)日：2012-08-28

申请号：US13230654

申请日：2011-09-12

Applicant: Lars G. Liljeryd ,  Kristofer Kjoerling ,  Per Ekstrand ,  Frederik Henn

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

IPC: G10L19/00

CPC classification number: G10L19/028 ,  G10L19/035 ,  G10L19/06 ,  G10L19/26 ,  G10L19/265 ,  G10L21/038 ,  G10L25/18

Abstract: Methods and an apparatus for enhancement of source coding systems utilizing high frequency reconstruction (HFR) are introduced. The problem of insufficient noise contents is addressed in a reconstructed highband, by using Adaptive Noise-floor Addition. New methods are also introduced for enhanced performance by means of limiting unwanted noise, interpolation and smoothing of envelope adjustment amplification factors. The methods and apparatus used are applicable to both speech coding and natural audio coding systems.

公开(公告)号：US20110302230A1

公开(公告)日：2011-12-08

申请号：US13201572

申请日：2010-02-17

Applicant: Per Ekstrand

Inventor： Per Ekstrand

IPC: G06F17/10

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: The document relates to modulated sub-sampled digital filter banks, as well as to methods and systems for the design of such filter banks. In particular, the present document proposes a method and apparatus for the improvement of low delay modulated digital filter banks. The method employs modulation of an asymmetric low-pass prototype filter and a new method for optimizing the coefficients of this filter. Further, a specific design for a (64) channel filter bank using a prototype filter length of (640) coefficients and a system delay of (319) samples is given. The method substantially reduces artifacts due to aliasing emerging from independent modifications of subband signals, for example when using a filter bank as a spectral equalizer. The method is preferably implemented in software, running on a standard PC or a digital signal processor (DSP), but can also be hardcoded on a custom chip. The method offers improvements for various types of digital equalizers, adaptive filters, multiband companders and spectral envelope adjusting filterbanks used in high frequency reconstruction (HFR) or parametric stereo systems.

Abstract translation: 该文件涉及调制的次采样数字滤波器组，以及用于设计这种滤波器组的方法和系统。 特别地，本文件提出了一种用于改进低延迟调制数字滤波器组的方法和装置。 该方法采用非对称低通原型滤波器的调制和用于优化滤波器系数的新方法。 此外，给出了使用（640）系数的原型滤波器长度和（319）个样本的系统延迟的（64）信道滤波器组的具体设计。 该方法基本上减少了由于子带信号的独立修改引起的混叠所产生的伪像，例如当使用滤波器组作为频谱均衡器时。 该方法优选地以在标准PC或数字信号处理器（DSP）上运行的软件实现，但也可以在定制芯片上被硬编码。 该方法为各种类型的数字均衡器，自适应滤波器，多频带压缩器以及用于高频重构（HFR）或参数立体声系统的频谱包络调整滤波器组提供了改进。

公开(公告)号：US08036882B2

公开(公告)日：2011-10-11

申请号：US12491001

申请日：2009-06-24

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

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

IPC: G10L19/00

CPC classification number: G10L19/028 ,  G10L19/035 ,  G10L19/06 ,  G10L19/26 ,  G10L19/265 ,  G10L21/038 ,  G10L25/18

Abstract: Methods and an apparatus for enhancement of source coding systems utilizing high frequency reconstruction (HFR) are introduced. The problem of insufficient noise contents is addressed in a reconstructed highband, by using Adaptive Noise-floor Addition. New methods are also introduced for enhanced performance by means of limiting unwanted noise, interpolation and smoothing of envelope adjustment amplification factors. The methods and apparatus used are applicable to both speech coding and natural audio coding systems.

公开(公告)号：US08036880B2

公开(公告)日：2011-10-11

申请号：US12490969

申请日：2009-06-24

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

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

IPC: G10L19/00

CPC classification number: G10L19/028 ,  G10L19/035 ,  G10L19/06 ,  G10L19/26 ,  G10L19/265 ,  G10L21/038 ,  G10L25/18

Abstract: Methods and an apparatus for enhancement of source coding systems utilizing high frequency reconstruction (HFR) are introduced. The problem of insufficient noise contents is addressed in a reconstructed highband, by using Adaptive Noise-floor Addition. New methods are also introduced for enhanced performance by means of limiting unwanted noise, interpolation and smoothing of envelope adjustment amplification factors. The methods and apparatus used are applicable to both speech coding and natural audio coding systems.

公开(公告)号：US20100211399A1

公开(公告)日：2010-08-19

申请号：US12703553

申请日：2010-02-10

Applicant: Lars Liljeryd ,  Per Ekstrand ,  Fredrik Henn ,  Kristofer Kjorling

Inventor： Lars Liljeryd ,  Per Ekstrand ,  Fredrik Henn ,  Kristofer Kjorling

IPC: G06F17/00

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.

Abstract translation: 本发明涉及使用频率转换或折叠或其组合来改进高频重建（HFR）技术的新方法和装置。 所提出的发明适用于音频源编码系统，并提供显着降低的计算复杂度。 这通过在子带域中的频率转换或折叠来实现，优选地与同一域中的频谱包络调整集成。 进一步提出了不一致保卫带滤波的概念。 所提出的发明提供了一种在语音和自然音频编码应用中有用的低复杂度，中等质量的HFR方法。

公开(公告)号：US20060031065A1

公开(公告)日：2006-02-09

申请号：US11246284

申请日：2005-10-11

Applicant: Lars Liljeryd ,  Kristofer Kjorling ,  Per Ekstrand ,  Fredrik Henn

Inventor： Lars Liljeryd ,  Kristofer Kjorling ,  Per Ekstrand ,  Fredrik Henn

IPC: G10L19/04

CPC classification number: G10L19/06 ,  G10L19/0208 ,  G10L19/022 ,  G10L19/035 ,  G10L21/038 ,  G10L25/18

Abstract: The present invention provides a new method and an apparatus for spectral envelope encoding. The invention teaches how to perform and signal compactly a time/frequency mapping of the envelope representation, and further, encode the spectral envelope data efficiently using adaptive time/frequency directional coding. The method is applicable to both natural audio coding and speech coding systems and is especially suited for coders using SBR [WO 98/57436] or other high frequency reconstruction methods.

公开(公告)号：US09159337B2

公开(公告)日：2015-10-13

申请号：US13503248

申请日：2010-05-25

Applicant: Lars Villemoes ,  Per Ekstrand ,  Sascha Disch ,  Frederik Nagel ,  Stephan Wilde

Inventor： Lars Villemoes ,  Per Ekstrand ,  Sascha Disch ,  Frederik Nagel ,  Stephan Wilde

IPC: H04R3/04 ,  G10L21/038 ,  G10L19/025

CPC classification number: G10L21/038 ,  G10L19/025

Abstract: An apparatus for generating a high frequency audio signal that includes an analyzer for analyzing an input signal to determine a transient information adaptively. Additionally a spectral converter is provided for converting the input signal into an input spectral representation. A spectral processor processes the input spectral representation to generate a processed spectral representation including values for higher frequencies than the input spectral representation. A time converter is configured for converting the processed spectral representation to a time representation, wherein the spectral converter or the time converter are controllable to perform a frequency domain oversampling for the first portion of the input signal having the transient information associated and to not perform the frequency domain oversampling for the second portion of the input signal not having the associated transient information.

Abstract translation: 一种用于产生高频音频信号的装置，包括用于分析输入信号的分析器，以自适应地确定瞬时信息。 另外，提供了用于将输入信号转换为输入频谱表示的频谱转换器。 频谱处理器处理输入频谱表示以产生包括比输入频谱表示更高频率的值的经处理的频谱表示。 时间转换器被配置为将经处理的频谱表示转换为时间表示，其中频谱转换器或时间转换器是可控制的，以对具有相关联的瞬态信息的输入信号的第一部分执行频域过采样，并且不执行 输入信号的第二部分不具有相关联的瞬态信息的频域过采样。

公开(公告)号：US08886346B2

公开(公告)日：2014-11-11

申请号：US13499893

申请日：2010-05-25

Applicant: Lars Villemoes ,  Per Ekstrand

Inventor： Lars Villemoes ,  Per Ekstrand

IPC: G06F17/00 ,  G10L21/038

CPC classification number: G10L21/038 ,  G10L19/0204 ,  G10L19/022 ,  G10L19/265

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.

Abstract translation: 本发明涉及音频信号的编码，特别涉及包括频域谐波转移器的高频重构方法。 描述了用于从信号的低频分量产生信号的高频分量的系统和方法。 该系统包括分析滤波器组（501），其包括频率分辨率为＆Dgr; f的分析变换单元（601） 和具有DA持续时间的分析窗口（611）; 所述分析滤波器组（501）被配置为从所述信号的低频分量提供一组分析子带信号; 非线性处理单元（502,650），被配置为基于所述一组分析子带信号来确定一组合成子带信号，其中所述一组分析子带信号的所述部分被相移一个换位阶数T; f）具有频率分辨率为Q＆Dgr; f的合成变换单元（602）的合成滤波器组（504） 和具有持续时间Ds的合成窗口（612）; 所述合成滤波器组（504）被配置为从所述一组合成子带信号中产生所述信号的高频分量; 其中Q是具有Q≥1且小于置换次数T的频率分辨率因子; 并且其中基于频率分辨率因子Q选择频率分辨率＆Dgr; f的乘积值和分析滤波器组的持续时间DA。