Telefonaktiebolaget Lm Ericsson (publ)

Dolby Laboratories Licensing Corporation

Dolby International Ab

Stefan Bruhn

Jonas Svedberg

Karl Hellwig

Martin Sehlstedt

Erik Norvell

David S McGrath

Tomas Frankkila

Volodya Grancharov

Juan Felix Torres

Michael Eckert

Daniel Enström

Tomas Jansson Toftgård

Anisse Taleb

Ingemar Johansson

Harald Pobloth

Heiko Purnhagen

Sigurdur Sverrisson

Stefanie Brown

Stefan Hakansson

Susanne Olvenstam

Per Skillermark

Willem Bastiaan Kleijn

Magnus K Almgren

Fredrik Klas Jansson

Erik Ekudden

Stefan Håkansson

Tomas Lundberg

Patrik Sandgren

Maria Hultström

Johan Nystrom

Johan Sjöberg

Brian B Lee

Moo Young Kim

Stefan Häkansson

Klas Fredrik Janis Jansson

Peter Blocher

David S Mcgrath

Daniel ENSTRÖM

A method of generating a substitution frame for a lost audio frame of an audio signal is presented. The method may comprise determining an audio filter based on samples of a valid audio frame preceding the lost audio frame. The method may comprise generating the substitution frame based on the audio filter and the samples of the valid audio frame preceding the lost audio frame. The method may be advantageously applied to a low frequency effects (LFE) channel of a multi-channel audio signal.

Frame loss concealment for a low-frequency effects channel

Transmitting node and receiving node for audio coding and methods therein. The nodes being operable to encode/decode speech and to apply a discontinuous transmission (DTX) scheme comprising transmission/reception of Silence Insertion Descriptor (SID) frames during speech inactivity. The method in the transmitting node comprising determining, from amongst a number N of hangover frames, a set Y of frames being representative of background noise, and further transmitting the N hangover frames, comprising at least said set Y of frames, to the receiving node. The method further comprises transmitting a first SID frame to the receiving node in association with the transmission of the N hangover frames, where the SID frame comprises information indicating the determined set Y of hangover frames to the receiving node. The method enables the receiving node to generate comfort noise based on the hangover frames most adequate for the purpose.

Methods and apparatuses for DTX hangover in audio coding

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

The disclosure herein generally relates to capturing, acoustic pre-processing, encoding, decoding, and rendering of directional audio of an audio scene. In particular, it relates to a device adapted to modify a directional property of a captured directional audio in response to spatial data of a microphone system capturing the directional audio. The disclosure further relates to a rendering device configured to modify a directional property of a received directional audio in response to received spatial data.

Audio processing in immersive audio services

There is provided mechanisms for frame loss concealment. A method is performed by a receiving entity. The method comprises adding, in association with constructing a substitution frame for a lost frame, a noise component to the substitution frame. The noise component has a frequency characteristic corresponding to a low-resolution spectral representation of a signal in a previously received frame.

Burst frame error handling

There is provided encoding and decoding methods for representing spatial audio that is a combination of directional sound and diffuse sound. An exemplary encoding method includes inter alia creating a single- or multi-channel downmix audio signal by downmixing input audio signals from a plurality of microphones in an audio capture unit capturing the spatial audio; determining first metadata parameters associated with the downmix audio signal, wherein the first metadata parameters are indicative of one or more of: a relative time delay value, a gain value, and a phase value associated with each input audio signal; and combining the created downmix audio signal and the first metadata parameters into a representation of the spatial audio.

Representing spatial audio by means of an audio signal and associated metadata

Concealing a lost audio frame of a received audio signal is provided by performing a sinusoidal analysis of a part of a previously received or reconstructed audio signal, wherein the sinusoidal analysis involves identifying frequencies of sinusoidal components of the audio signal, applying a sinusoidal model on a segment of the previously received or reconstructed audio signal, wherein said segment is used as a prototype frame in order to create a substitution frame for a lost audio frame, and creating the substitution frame for the lost audio frame by time-evolving sinusoidal components of the prototype frame, up to the time instance of the lost audio frame, in response to the corresponding identified frequencies.

Audio frame loss concealment

The present document describes a method () for generating a bitstream (), wherein the bitstream () comprises a sequence of superframes () for a sequence of frames of an immersive audio signal (). The method () comprises, repeatedly for the sequence of superframes (), inserting () coded audio data () for one or more frames of one or more downmix channel signals () derived from the immersive audio signal (), into data fields () of a superframe (); and inserting () metadata () for reconstructing one or more frames of the immersive audio signal () from the coded audio data (), into a metadata field () of the superframe ().

Methods and devices for generating or decoding a bitstream comprising immersive audio signals

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 method performed by an encoder. The method comprises determining envelope representation residual coefficients as first compressed envelope representation coefficients subtracted from the input envelope representation coefficients. The method comprises transforming the envelope representation residual coefficients into a warped domain so as to obtain transformed envelope representation residual coefficients. The method comprises applying, at least one of a plurality of gain-shape coding schemes on the transformed envelope representation residual coefficients in order to achieve gain-shape coded envelope representation residual coefficients, where the plurality of gain-shape coding schemes have mutually different trade-offs in one or more of gain resolution and shape resolution for one or more of the transformed envelope representation residual coefficients. The method comprises transmitting, over a communication channel to a decoder, a representation of the first compressed envelope representation coefficients, the gain-shape coded envelope representation residual coefficients, and information on the at least one applied gain-shape coding scheme.

Methods, encoder and decoder for handling envelope representation coefficients

In accordance with an example embodiment of the present invention, disclosed is a method and an apparatus thereof for selecting a packet loss concealment procedure for a lost audio frame of a received audio signal. A method for selecting a packet loss concealment procedure comprises detecting an audio type of a received audio frame and determining a packet loss concealment procedure based on the audio type. In the method, detecting an audio type comprises determining a stability of a spectral envelope of signals of received audio frames.

Selecting a packet loss concealment procedure

Concealing a lost audio frame of a received audio signal is provided by performing a sinusoidal analysis () of a part of a previously received or reconstructed audio signal, wherein the sinusoidal analysis involves identifying frequencies of sinusoidal components of the audio signal, applying a sinusoidal model on a segment of the previously received or reconstructed audio signal, wherein said segment is used as a prototype frame in order to create a substitution frame for a lost audio frame, and creating the substitution frame () for the lost audio frame by time-evolving sinusoidal components of the prototype frame, up to the time instance of the lost audio frame, in response to the corresponding identified frequencies.

Growing community of inventors

Sollentuna, Sweden

Stefan Bruhn