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：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：WO2022066313A1

公开(公告)日：2022-03-31

申请号：PCT/US2021/045976

申请日：2021-08-13

Applicant: APPLE INC.

Inventor： KIM, Moo-Young ,  ZAMANI, Sina ,  SEN, Dipanjan

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

Abstract: Encoding and decoding of higher order ambisonics, HOA, data for purposes of bitrate reduction. One aspect uses principal components analysis to produce spatial descriptors. Other aspects include various spatial descriptor quantization techniques.

公开(公告)号：EP4471764A1

公开(公告)日：2024-12-04

申请号：EP24177351.4

申请日：2024-05-22

Applicant: Apple Inc.

Inventor： SEN, Dipanjan ,  ATTI, Venkatraman

IPC: G10L19/038

Abstract: Aspects of the present disclosure provide improved techniques for coding audio signal with a transient audio sound. Improved techniques include parsing a frame of predetermined length of audio samples into a series of windows of a smaller size, and transforming the windows of time-domain samples into a series of windows of frequency-domain samples. In an aspect coding of the frequency-domain samples may include vector quantization of vectors formed of frequency-domain samples selected from across the frame.

公开(公告)号：EP4471763A1

公开(公告)日：2024-12-04

申请号：EP24178003.0

申请日：2024-05-24

Applicant: Apple Inc.

Inventor： SEN, Dipanjan ,  ATTI, Venkatraman

IPC: G10L19/022 ,  G10L19/02

Abstract: Aspects of the present disclosure provide improved techniques for coding audio signal with a transient audio sound. Improved techniques include parsing a frame of predetermined length of audio samples into a series of windows of a smaller size, and transforming the windows of time-domain samples into a series of windows of frequency-domain samples. The frequency-domain samples may be organized according to an alignment pattern and may be coded with respect to an envelope of the organized frequency-domain samples.