Dolby Laboratories Licensing Corporation

Dolby International Ab

Michael Eckert

Glenn N Dickins

David S McGrath

Stefan Bruhn

Shen Huang

Heiko Purnhagen

Xuejing Sun

Hannes Muesch

David Gunawan

Juan Felix Torres

Gary Spittle

Paul Francis Holmberg

Erwin Goesnar

Stefanie Brown

Michael P Hollier

Richard James Cartwright

Dirk Jeroen Breebaart

Feng Deng

Rishabh Tyagi

Craig Johnston

Poppy Crum

Jean-Francois Catz

David S Mcgrath

Paul Holmberg

The present document describes a method () for encoding a multi-channel input signal () which comprises N different channels. The method () comprises, for a current frame of a sequence of frames, determining () whether the current frame is an active frame or an inactive frame using a signal and/or a voice activity detector, and determining () a downmix signal () based on the multi-channel input signal (), wherein the downmix signal () comprises N channels or less. In addition, the method () comprises determining () upmixing metadata () comprising a set of parameters for generating, based on the downmix signal (), a reconstructed multi-channel signal () comprising N channels, wherein the upmixing metadata () is determined in dependence of whether the current frame is an active frame or an inactive frame. The method () further comprises encoding () the upmixing metadata () into a bitstream.

Methods and devices for encoding and/or decoding spatial background noise within a multi-channel input signal

A method comprising receiving a first input bit stream for a first parametrically coded input audio signal, the first input bit stream including data representing a first input core audio signal and a first set including at least one spatial parameter relating to the first parametrically coded input audio signal. A first covariance matrix of the first parametrically coded audio signal is determined based on the spatial parameter(s) of the first set. A modified set including at least one spatial parameter is determined based on the determined first covariance matrix, wherein the modified set is different from the first set. An output core audio signal is determined, which is based on, or constituted by, the first input core audio signal. An output bit stream for a parametrically coded output audio signal is generated, the output bit stream including data representing the output core audio signal and the modified set.

Processing parametrically coded audio

The present document describes a method () for encoding a multi-channel input signal (). The method () comprises determining () a plurality of downmix channel signals () from the multi-channel input signal () and performing () energy compaction of the plurality of downmix channel signals () to provide a plurality of compacted channel signals (). Furthermore, the method () comprises determining () joint coding metadata () based on the plurality of compacted channel signals () and based on the multi-channel input signal (), wherein the joint coding metadata () is such that it allows upmixing of the plurality of compacted channel signals () to an approximation of the multi-channel input signal (). In addition, the method () comprises encoding () the plurality of compacted channel signals () and the joint coding metadata ().

Methods and devices for encoding and/or decoding immersive audio signals

Systems and methods for providing forward error correction for a multi-channel audio signal are described. Blocks of an audio stream are buffered into a frame. A transformation can be applied that compacts the energy of each block into a plurality of transformed channels. The energy compaction transform may compact the most energy of a block into the first transformed channel and to compact decreasing amounts of energy into each subsequent transformed channel. The transformed frame may be encoded using any suitable codec and transmitted in a packet over a network. Improved forward error correction may be provided by attaching a low bit rate encoding of the first transformed channel to a subsequent packet. To reconstruct a lost packet, the low bit rate encoding of the first channel for the lost packet may be combined with a packet loss concealment version of the other channels, constructed from a previously-received packet.

Selective forward error correction for spatial audio codecs

The disclosed embodiments enable converting audio signals captured in various formats by various capture devices into a limited number of formats that can be processed by an audio codec (e.g., an Immersive Voice and Audio Services (IVAS) codec). In an embodiment, a simplification unit of the audio device receives an audio signal captured by one or more audio capture devices coupled to the audio device. The simplification unit determines whether the audio signal is in a format that is supported/not supported by an encoding unit of the audio device. Based on the determining, the simplification unit, converts the audio signal into a format that is supported by the encoding unit. In an embodiment, if the simplification unit determines that the audio signal is in a spatial format, the simplification unit can convert the audio signal into a spatial 'mezzanine' format supported by the encoding.

Transforming audio signals captured in different formats into a reduced number of formats for simplifying encoding and decoding operations

A communication system, method, and computer-readable medium therefor comprise a media server configured to receive a plurality of audio streams from a corresponding plurality of client devices, the media server including circuitry configured to rank the plurality of audio streams based on a predetermined metric, group a first portion of the plurality of audio streams into a first set, the first portion of the plurality of audio streams being the N highest-ranked audio streams, group a second portion of the plurality of audio streams into a second set, the second portion of the plurality of audio streams being the M lowest-ranked audio streams, forward respective audio streams of the first set to a receiver device, and discard respective audio streams of the second set, wherein N and M are independent integers.

Scalable voice scene media server

Systems and methods are described for determining orientation of an external audio device in a video conference, which may be used to provide congruent multimodal representation for a video conference. A camera of a video conferencing system may be used to detect a potential location of an external audio device within a room in which the video conferencing system is providing a video conference. Within the detected potential location, a visual pattern associated with the external audio device may be identified. Using the identified visual pattern, the video conferencing system may estimate an orientation of the external audio device, the orientation being used by the video conferencing system to provide spatial audio video congruence to a far end audience.

Multimodal spatial registration of devices for congruent multimedia communications

A method for processing audio data, the method comprising: receiving audio data corresponding to a plurality of instances of audio, including at least one of: (a) audio data from multiple endpoints, recorded separately or (b) audio data from a single endpoint corresponding to multiple talkers and including spatial information for each of the multiple talkers; rendering the audio data in a virtual acoustic space such that each of the instances of audio has a respective different virtual position in the virtual acoustic space; and scheduling the instances of audio to be played back with a playback overlap between at least two of the instances of audio, wherein the scheduling is performed, at least in part, according to a set of perceptually-motivated rules.

Scheduling playback of audio in a virtual acoustic space

A method of outputting audio in a teleconferencing environment includes receiving audio streams, processing the audio streams according to information regarding effective spatial positions, and outputting, by at least three speakers arranged in more than one dimension, the audio streams having been processed. The information regarding the plurality of effective spatial positions corresponds to a perceived spatial scene that extends beyond the speakers in at least two dimensions. In this manner, participants in the teleconference perceive the audio from the remote participants as originating at different positions in the teleconference room.

System and method of speaker cluster design and rendering

Example embodiments disclosed herein relate to spatial congruency adjustment. A method for adjusting spatial congruency in a video conference is disclosed. The method in unwarping a visual scene captured by a video endpoint device into at least one rectilinear scene, the video endpoint device being configured to capture the visual scene in an omnidirectional manner, detecting spatial congruency between the at least one rectilinear scene and an auditory scene captured by an audio endpoint device that is positioned in relation to the video endpoint device. The spatial congruency being a degree of alignment between the auditory scene and the at least one rectilinear scene and in response to the detected spatial congruency being below the threshold, adjusting the spatial congruency. Corresponding system and computer program products are also disclosed.

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Ashfield, Australia

Michael Eckert