公开(公告)号：WO2022046533A1

公开(公告)日：2022-03-03

申请号：PCT/US2021/046810

申请日：2021-08-20

Applicant: APPLE INC.

Inventor： BAUMGARTE, Frank

IPC: G10L19/008 ,  H04S3/00

Abstract: Disclosed is an audio codec that represents an immersive signal by a two-channel stereo signal that is a stereo rendering of the immersive signal and directional parameters. The directional parameters may be based on a perceptual model describing the direction of virtual speaker pairs to recreate the perceived location of dominant sounds. Audio processing at the decoder may be performed on the stereo signal in the frequency domain for multiple channel pairs using time-frequency tiles. Spatial localization of the audio signals may use a panning approach by applying weightings to the time-frequency tiles of the stereo signal for each output channel pair. The weightings for the time-frequency tiles may be derived based on the directional parameters, an analysis of the stereo signal, and the output channel layout. The weightings may be used to adaptively process the time-frequency tiles using a de-correlator to reduce or minimize spectral distortions from spatial rendering.

公开(公告)号：WO2011026083A1

公开(公告)日：2011-03-03

申请号：PCT/US2010/047269

申请日：2010-08-31

Applicant: APPLE INC. ,  BAUMGARTE, Frank ,  STEWART, William ,  KUO, Shyh-Shiaw

Inventor： BAUMGARTE, Frank ,  STEWART, William ,  KUO, Shyh-Shiaw

IPC: G10L19/00 ,  G10L19/02 ,  G10L19/14

CPC classification number: G10L19/24

Abstract: Methods, systems, and apparatus are presented for decoding an audio signal that includes bandwidth extension data. An audio signal that includes core audio data and bandwidth extension data can be received in a decoder. The core audio data can be associated with a core portion of an audio signal, such as the frequency range below a cutoff frequency, and the bandwidth extension data can be associated with an extended portion of the audio signal, such as a frequency range above the cutoff frequency. The core audio data can be decoded to generate a decoded core audio signal in a time domain representation. Further, an extended portion of the audio signal can be reconstructed in accordance with extension data and decoded core audio signal. Additionally, the decoded core audio signal can be lowpass filtered and the extended portion can be highpass filtered before being combined to generate a decoded output signal.

Abstract translation: 呈现用于对包括带宽扩展数据的音频信号进行解码的方法，系统和装置。 可以在解码器中接收包括核心音频数据和带宽扩展数据的音频信号。 核心音频数据可以与诸如低于截止频率的频率范围的音频信号的核心部分相关联，并且带宽扩展数据可以与音频信号的扩展部分相关联，例如高于 截止频率。 核心音频数据可以被解码以在时域表示中产生解码的核心音频信号。 此外，可以根据扩展数据和解码的核心音频信号来重构音频信号的扩展部分。 此外，解码的核心音频信号可以被低通滤波，并且扩展部分可以在被组合之前被高通滤波以产生解码的输出信号。

公开(公告)号：WO2022066426A1

公开(公告)日：2022-03-31

申请号：PCT/US2021/049744

申请日：2021-09-10

Applicant: APPLE INC.

Inventor： KIM, Moo Young ,  SEN, Dipanjan ,  ALLAMANCHE, Eric ,  CALHOUN, J. Kevin ,  BAUMGARTE, Frank ,  ZAMANI, Sina ,  DAY, Eric

IPC: G10L19/18 ,  G10L19/24 ,  G10L19/008 ,  H04S3/02

Abstract: Disclosed are methods and systems for decoding immersive audio content encoded by an adaptive number of scene elements for channels, audio objects, higher-order ambisonics (HOA), and/or other sound field representations. The decoded audio is rendered to the speaker configuration of a playback device. For bit streams that represent audio scenes with a different mixture of channels, objects, and/or HOA in consecutive frames, fade-in of the new frame and fade-out of the old frame may be performed. Crossfading between consecutive frames happen in the speaker layout after rendering, in the spatially decoded content type before rendering, or between the transport channels as the output of the baseline decoder but before spatial decoding and rendering. Crossfading may use an immediate fade-in and fade-out frame (IFFF) for the transition frame or may use an overlap-add synthesis technique such as time-domain aliasing cancellation (TDAC) of MDCT.

公开(公告)号：WO2017023601A1

公开(公告)日：2017-02-09

申请号：PCT/US2016/043932

申请日：2016-07-25

Applicant: APPLE INC.

Inventor： BAUMGARTE, Frank

IPC: G10L19/008 ,  H04S3/00

CPC classification number: G10L19/008 ,  H04S3/008 ,  H04S2400/13 ,  H04S2400/15 ,  H04S2420/07

Abstract: An audio encoder encodes a digital audio recording having a number of audio channels or audio objects. A Dynamic Range Control (DRC) processor produces a sequence of encoder DRC gain values, by applying a selected one of a number of DRC characteristics to a group of one or more of the audio channels or audio objects. The encoder DRC gain values are to be applied to adjust the group of audio channels or audio objects, upon decoding them from the encoded digital audio recording. A bitstream multiplexer combines a) the encoded digital audio recording with b) the sequence of encoder DRC gain values, an indication of the selected DRC characteristic, and an indication of an alternate DRC characteristic, the latter as metadata associated with the encoded digital audio recording. Other embodiments are also described including a system for decoding the encoded audio recording and performing DRC adjustment upon it.

Abstract translation: 音频编码器对具有多个音频通道或音频对象的数字音频记录进行编码。 动态范围控制（DRC）处理器通过将多个DRC特性中选择的一个应用到一个或多个音频通道或音频对象的组来产生编码器DRC增益值序列。 在编码数字音频记录中对编码器DRC增益值进行解码时，将应用编码器DRC增益值来调整音频通道或音频对象组。 比特流多路复用器将a）编码的数字音频记录与b）编码器DRC增益值的序列，所选择的DRC特性的指示以及替代DRC特性的指示，后者作为与编码的数字音频记录相关联的元数据 。 还描述了其他实施例，其包括用于对编码的音频记录进行解码并在其上执行DRC调整的系统。

公开(公告)号：WO2017058731A1

公开(公告)日：2017-04-06

申请号：PCT/US2016/053811

申请日：2016-09-26

Applicant: APPLE INC.

Inventor： BAUMGARTE, Frank

IPC: H03G7/00 ,  G10L19/00

CPC classification number: H04R3/04 ,  G06F3/165 ,  G10L19/00 ,  G10L19/167 ,  H03G5/165 ,  H03G7/007 ,  H04N21/8113 ,  H04N21/84 ,  H04R2430/01

Abstract: Dynamic loudness equalization of received audio content in a playback system, using metadata that includes instantaneous loudness values for the audio content. A playback level is derived from a user volume setting of the playback system, and is compared with a mixing level that is assigned to the audio content. Parameters are computed, that define an equalization filter that is filtering the audio content before driving a speaker with the filtered audio content, based on the instantaneous loudness values and the comparing of the playback level with the assigned mixing level. Other embodiments are also described and claimed.

Abstract translation: 使用包含音频内容的瞬时响度值的元数据，在播放系统中接收音频内容的动态响度均衡。 从播放系统的用户音量设置导出播放级别，并将其与分配给音频内容的混合级别进行比较。 计算参数，其基于瞬时响度值和重放级别与分配的混合级别的比较，定义在驱动具有滤波的音频内容的扬声器之前对音频内容进行滤波的均衡滤波器。 还描述和要求保护其他实施例。

公开(公告)号：EP2473994A1

公开(公告)日：2012-07-11

申请号：EP10757502.9

申请日：2010-08-31

Applicant: Apple Inc.

Inventor： BAUMGARTE, Frank ,  STEWART, William ,  KUO, Shyh-Shiaw

IPC: G10L19/00 ,  G10L19/02 ,  G10L19/14

CPC classification number: G10L19/24

Abstract: Methods, systems, and apparatus are presented for decoding an audio signal that includes bandwidth extension data. An audio signal that includes core audio data and bandwidth extension data can be received in a decoder. The core audio data can be associated with a core portion of an audio signal, such as the frequency range below a cutoff frequency, and the bandwidth extension data can be associated with an extended portion of the audio signal, such as a frequency range above the cutoff frequency. The core audio data can be decoded to generate a decoded core audio signal in a time domain representation. Further, an extended portion of the audio signal can be reconstructed in accordance with extension data and decoded core audio signal. Additionally, the decoded core audio signal can be lowpass filtered and the extended portion can be highpass filtered before being combined to generate a decoded output signal.

公开(公告)号：WO2022066370A1

公开(公告)日：2022-03-31

申请号：PCT/US2021/048354

申请日：2021-08-31

Applicant: APPLE INC.

Inventor： SEN, Dipanjan ,  KIM, Moo Young ,  BAUMGARTE, Frank ,  ZAMANI, Sina ,  LINDAHL, Aram

IPC: G10L19/008 ,  G10L19/24 ,  H04S3/00

Abstract: Disclosed is a hierarchical spatial resolution codec that adaptively adjusts the representations of immersive audio content as the target bandwidth for delivering the audio content changes. The audio content may be represented by an adaptive number of content types such as channels/objects, higher-order ambisonics (HOA), and encoded by adaptive spatial coding techniques to support the target bitrate of a transmission channel or user. Adaptive spatial coding techniques may include adaptive channel/object spatial encoding techniques to generate an adaptive number of channels/objects, and adaptive HOA spatial encoding or HOA compression techniques to generate an adaptive order of the HOA. The adaptation may be a function of the target bitrate that is associated with a desired quality, and an analysis that determines the priority of the channels, objects, and HOA. High priority channels/objects may be encoded into a high quality bit-stream while low priority channels/objects may be converted and encoded as HOA.

公开(公告)号：WO2017023423A1

公开(公告)日：2017-02-09

申请号：PCT/US2016/037240

申请日：2016-06-13

Applicant: APPLE INC.

Inventor： BAUMGARTE, Frank

IPC: G11B27/031 ,  G11B27/32 ,  H04S3/00 ,  H04S7/00

CPC classification number: G10L19/26 ,  G10L19/008 ,  G10L19/167 ,  G11B27/031 ,  G11B27/322 ,  H04S3/006 ,  H04S3/008 ,  H04S7/307 ,  H04S2400/03 ,  H04S2400/13 ,  H04S2400/15

Abstract: A system for producing an encoded digital audio recording has an audio encoder that encodes a digital audio recording having a number of audio channels or audio objects. An equalization (EQ) value generator produces a sequence of EQ values which define EQ filtering that is to be applied when decoding the encoded digital audio recording, wherein the EQ filtering is to be applied to a group of one or more of the audio channels or audio objects of the recording independent of any downmix. A bitstream multiplexer combines the encoded digital audio recording with the sequence of EQ values, the latter as metadata associated with the encoded digital audio recording. Also described is a system for decoding the encoded audio recording.

Abstract translation: 用于产生编码数字音频记录的系统具有对具有多个音频通道或音频对象的数字音频记录进行编码的音频编码器。 均衡（EQ）值发生器产生一系列EQ值，其定义在对编码的数字音频记录进行解码时应用的EQ滤波，其中将EQ滤波应用于一个或多个音频信道的组或 音频对象的录音独立于任何下混。 比特流多路复用器将编码的数字音频记录与EQ值序列组合，后者作为与编码的数字音频记录相关联的元数据。 还描述了用于对编码的音频记录进行解码的系统。

公开(公告)号：WO2014160849A2

公开(公告)日：2014-10-02

申请号：PCT/US2014/031992

申请日：2014-03-27

Applicant: APPLE INC.

Inventor： BAUMGARTE, Frank ,  ALLAMANCHE, Eric A. ,  STROMMER, Stefan K.O.

IPC: G10L19/008

CPC classification number: H03G3/20 ,  G10L19/008 ,  G10L21/0316 ,  H03G7/007

Abstract: An audio normalization gain value is applied to an audio signal to produce a normalized signal. The normalized signal is processed to compute dynamic range control (DRC) gain values in accordance with a selected one of several pre-defined DRC characteristics. The audio signal is encoded, and the DRC gain values are provided as metadata associated with the encoded audio signal. Several other embodiments are also described and claimed.

Abstract translation: 将音频归一化增益值应用于音频信号以产生归一化信号。 处理归一化信号以根据几个预定义的DRC特性中选择的一个来计算动态范围控制（DRC）增益值。 音频信号被编码，并且提供DRC增益值作为与编码的音频信号相关联的元数据。 还描述和要求保护的其它几个实施例。

公开(公告)号：EP3329487B1

公开(公告)日：2019-12-11

申请号：EP16748414.6

申请日：2016-07-25

Applicant: Apple Inc.

Inventor： BAUMGARTE, Frank

IPC: G10L19/008 ,  H04S3/00