Qualcomm Incorporated

Apple Inc.

Dipanjan Sen

Nils Günther Peters

Moo Young Kim

Martin James Morrell

S M Akramus Salehin

Shankar Thagadur Shivappa

Pei Xiang

Siddhartha Goutham Swaminathan

Frank M Baumgarte

Ferdinando Olivieri

Sang-Uk Ryu

Thomas Stockhammer

Ricardo De Jesus Bernal Castillo

Richard Paul Walters

Jeongook Song

Juha O Merimaa

Eric A Allamanche

Isaac Garcia Munoz

Nils Gunther Peters

Wenliang Lu

Michael Ericson

Sina Zamani

Aram M Lindahl

Jonathan D Sheaffer

Joshua D Atkins

Symeon Delikaris Manias

Wade Lyle Heimbigner

Eric Stephen Mattis

Peter A Raffensperger

Jason Filos

Mark Adam Cherry

Gaetan R Lorho

Eric J Day

Daniel Weber

Martin Morrell

Kerry Titus Hartman

J Kevin Calhoun

Akramus S M Salehin

A method that includes receiving a bitstream that comprises: an encoded version of an audio signal that is associated with a sound source that is within a first 3D scene, a scene tree structure that includes an origin of the first scene relative to an origin of a second scene, and a position of the sound source within the first scene relative to the origin of the first scene, wherein the position references the origin of the first scene using an identifier, wherein the scene tree structure defines an initial configuration of the sound source with respect to the first and second scenes; determining a position of a listener; producing a set of spatially rendered audio signals by spatially rendering the audio signal according to the position of the sound source with respect to the position of the listener; and using the spatially rendered audio signals to drive speakers.

Method and system for efficiently encoding scene positions

In general, techniques are described by which to synchronize enhanced audio transports with backward compatible audio transports. A device comprising a memory and one or more processors may be configured to perform the techniques. The memory may store a backward compatible bitstream conforming to a legacy transport format. The processor may obtain, from the backward compatible bitstream, a first audio transport stream, and obtain, from the backward compatible bitstream, a second audio transport stream. The processor(s) may also obtain, from the backward compatible bitstream, indications representative of synchronization information for the first audio transport stream and the second audio transport stream. The processor(s) may synchronize, based on the indications, the first audio transport stream and the second audio transport to obtain synchronized audio data stream. The processor(s) may obtain, based the synchronized audio data, enhanced audio data, and output the enhanced audio data to one or more speakers.

Synchronizing enhanced audio transports with backward compatible audio transports

A method that includes receiving a first bitstream that includes an encoded version of an audio signal for a three-dimensional (3D) scene and a first set of metadata that has 1) a position of a 3D sub-scene within the scene and 2) a position of a sound source associated with the audio signal within the sub-scene; determining a position of a listener; spatially rendering the scene to produce the sound source with the audio signal at the position of the sound source with respect to the position of the listener; receiving a second bitstream that includes a second set of metadata that has a different position of the sub-scene; and adjusting the spatial rendering of the scene such that the position of the sound source changes to correspond to movement of the sub-scene from the position of the sub-scene to the different position of the sub-scene.

Method and system for spatially rendering three-dimensional (3D) scenes

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.

Hierarchical spatial resolution codec

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.

Seamless scalable decoding of channels, objects, and HOA audio content

An example device includes a memory configured to store a plurality of representations of a soundfield, each representation of the soundfield comprising a different set of ambisonic coefficients representative of the same soundfield at concurrent periods of time. The device also includes a processor, coupled to the memory, and the processor is configured to perform audio playback based on a field of view and on a particular representation of the soundfield from the plurality of representations.

Mixed-order ambisonics (MOA) audio data for computer-mediated reality systems

An example audio decoding device includes a memory configured to store at least a portion of a coded audio bitstream; and one or more processors configured to: decode, based on the coded audio bitstream, a representation of a soundfield; decode, based on the coded audio bitstream, a syntax element indicating a selection of either a head-related transfer function (HRTF) or a binaural room impulse response (BRIR); and render, using the selected HRTF or BRIR, speaker feeds from the soundfield.

Signaling for rendering tools

In general, disclosed is a device that includes one or more processors, coupled to the memory, configured to perform an energy analysis with respect to one or more audio objects, in the ambisonics domain, in the first time segment. The one or more processors are also configured to perform a similarity measure between the one or more audio objects, in the ambisonics domain, in the first time segment, and the one or more audio objects, in the ambisonics domain, in the second time segment. In addition, the one or more processors are configured to perform a reorder of the one or more audio objects, in the ambisonics domain, in the first time segment with the one or more audio objects, in the ambisonics domain, in the second time segment, to generate one or more reordered audio objects in the first time segment.

Reordering of foreground audio objects in the ambisonics domain

A device and method for backward compatibility for virtual reality (VR), mixed reality (MR), augmented reality (AR), computer vision, and graphics systems. The device and method enable rendering audio data with more degrees of freedom on devices that support fewer degrees of freedom. The device includes memory configured to store audio data representative of a soundfield captured at a plurality of capture locations, metadata that enables the audio data to be rendered to support N degrees of freedom, and adaptation metadata that enables the audio data to be rendered to support M degrees of freedom. The device also includes one or more processors coupled to the memory, and configured to adapt, based on the adaptation metadata, the audio data to provide the M degrees of freedom, and generate speaker feeds based on the adapted audio data.

Six degrees of freedom and three degrees of freedom backward compatibility

A device with microphones can generate microphone signals during an audio recording. The device can store, in an electronic audio data file, the microphone signals, and metadata that includes impulse responses of the microphones. Other aspects are described and claimed.

Spatial audio file format for storing capture metadata

A device configured to decode a bitstream, where the device includes a memory configured to store a temporally encoded representation of spatial audio signals. The device is also configured to receive the bitstream that includes an indication of a spatial transformation, and includes a temporal decoding unit, coupled to the memory, configured to decode one or more spatial audio signals represented in a spatial domain, where the one or more spatial audio signals are associated with different angles in the spatial domain. In addition, the device includes an inverse spatial transformation unit, coupled to the temporal decoding unit, is configured to convert the one or more spatial audio signals represented in the spatial domain into at least three ambisonic coefficients that, in part, represent a soundfield in an ambisonics domain, and perform a spatial transformation of the soundfield based on the indication of the spatial transformation received in the bitstream.

Spatial transformation of ambisonic audio data

A first layer of data having a first set of Ambisonic audio components can be decoded where the first set of Ambisonic audio components is generated based on ambience and one or more object-based audio signals. A second layer of data is decoded having at least one of the one or more object-based audio signals. One of the object-based audio signals is subtracted from the first set of Ambisonic audio components. The resulting Ambisonic audio components are rendered to generate a first set of audio channels. The one or more object-based audio signals are spatially rendered to generate a second set of audio channels. Other aspects are described and claimed.

Layered coding of audio with discrete objects

In general, techniques are described by which to provide priority information for higher order ambisonic (HOA) audio data. A device comprising a memory and a processor may perform the techniques. The memory stores HOA coefficients of the HOA audio data, the HOA coefficients representative of a soundfield. The processor may decompose the HOA coefficients into a sound component and a corresponding spatial component, the corresponding spatial component defining shape, width, and directions of the sound component, and the corresponding spatial component defined in a spherical harmonic domain. The processor may also determine, based on one or more of the sound component and the corresponding spatial component, priority information indicative of a priority of the sound component relative to other sound components of the soundfield, and specify, in a data object representative of a compressed version of the HOA audio data, the sound component and the priority information.

Higher order ambisonic audio data

One or more processors may obtain a first distance between a first audio zone of the two or more audio zones associated with the one or more interest points within the first audio zone, and a first device position of a device, obtain a second distance between a second audio zone of the two or more audio zones associated with the one or more interest points within the second audio zone, and the first device position of the device, and obtain an updated first distance and updated second distance after movement of the device has changed from the first device position to a second device position. The one or more processor(s) may independently control the first audio zone and the second audio zone, such that the audio data within the first audio zone and the second audio zone are adjusted based on the updated first distance and updated second distance.

Rendering audio data from independently controlled audio zones

In general, techniques are described for rendering metadata to control user movement based audio rendering. A device comprising a memory and one or more processors may be configured to perform the techniques. The memory may be configured to store audio data representative of a soundfield. The one or more processors may be coupled to the memory, and configured to obtain rendering metadata indicative of controls for enabling or disabling adaptations, based on an indication of a movement of a user of the device, of a renderer used to render audio data representative of a soundfield, specify, in a bitstream representative of the audio data, the rendering metadata, and output the bitstream.

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San Diego, CA, United States of America

Dipanjan Sen