Orange

France Telecom

France Telecom Sa

Marc Emerit

Grégory Pallone

Jean-Philippe Thomas

David Virette

Stephane Ragot

Gregory Pallone

Bertrand Fatus

Jérôme Daniel

Pierrick Philippe

Stéphane Ragot

Julien Faure

Georges Buchner

Rozenn Nicol

Alexandre Guerin

Yannick Mahieux

Alain Saliou

Stéphane Louis Dit Picard

Alain Leyreloup

Robert Warzocha

Clément Gaultier

Thomas Joubaud

Felipe Rugeles Ospina

Robert Kolodynski

Andrzej Zielinski

The processing of a signal y(t) coming from a microphone of an equipment item including a loudspeaker intended to be supplied a signal x(t), limits an echo effect induced by the microphone capturing a sound emitted by the loudspeaker. This sound and any of its acoustic reflections follow an acoustic path w from the loudspeaker to the microphone. To limit the echo effect, the processing includes determining ŝ(t) a useful signal s(t) by subtracting from the signal y(t) an estimate of an echo signal x(t)*ŵ(t) given by applying a filter ŵ(t) to the signal x(t). The filter ŵ(t) is adaptive by variable step size to account for a change over time in the acoustic path w(t). The adaptive filter ŵ(t) is produced at each frame k of samples as a function of an update ΔWto the acoustic path w for this frame k and by applying a normalization Λ satisfying a criterion chosen for minimal variance.

Method and device for variable pitch echo cancellation

A method for calibrating a distributed audio reproduction system, including a set of N heterogeneous loudspeakers controlled by a server. This method includes the following steps: a) placing a microphone in front of a first loudspeaker of the set; b) capturing), by the microphone, a calibration signal sent to the loudspeaker at a first time and reproduced by same; c) capturing, by the microphone, the calibration signal sent with a known time delay to the N&#x2212;1 other loudspeakers of the set and reproduced by these N&#x2212;1 loudspeakers; d) capturing, by the microphone, the calibration signal sent to the first loudspeaker at a second time and reproduced again by same; e) repeating steps a) to d) for the N loudspeakers of the set; f) determining a plurality of heterogeneity factors to be corrected for the set of N loudspeakers by analysing the data thus captured; g) correcting the determined heterogeneity factors.

Calibration of a distributed sound reproduction system

A method of parametric coding of a multichannel digital audio signal including coding a signal arising from a channels reduction processing applied to the multichannel signal and coding spatialization information of the multichannel signal. The method includes the following acts: extraction of a plurality of items of spatialization information of the multichannel signal; obtaining at least one representation model of the extracted spatialization information; determination of at least one angle parameter of a model obtained; coding the at least one determined angle parameter so as to code the spatialization information extracted during the coding of spatialization information. Also provided are a method for decoding such a coded signal and corresponding coding and decoding devices.

Optimized coding and decoding of spatialization information for the parametric coding and decoding of a multichannel audio signal

Method and device for processing a video sequence containing a succession of images of one or more participant speakers, captured by a wide-angle camera. The method includes: capturing sound using a microphone having a plurality of sensors for capturing a sound field; processing the audio data captured by the microphone in order to determine at least one direction of origin of sound coming from a participant, relative to an optical axis of the wide-angle camera; generating a signal including data concerning the direction of origin of the sound relative to the optical axis of the camera, for the purpose of utilizing the signal when rendering the captured images by zooming into an area around the participant emitting the sound for which the direction of origin corresponds to the data of the signal.

Processing of data of a video sequence in order to zoom to a speaker detected in the sequence

The invention relates to a method for processing customized data representative of the directivity of an customized audio system, the method comprising the following steps: &#x2014;obtaining (), for each individual of an initial set of individuals, at least one customized suite of filters; &#x2014;determining () N independent components common to the suites of filters obtained; &#x2014;decomposing () each of the suites obtained into a first base constructed from the N independent components with a view to obtaining, for each suite of filters, a first suite of weighting coefficients; &#x2014;decomposing () each first suite of weighting coefficients into a second base of P independent components, so as to obtain a second suite of weighting coefficients; &#x2014;storing () each second suite of weighting coefficients obtained in association with an identifier of an individual from among the initial set of individuals.

Successive decompositions of audio filters

A method of sound spatialization, in which at least one filtering process, including summation, is applied, to at least two input signals, the filtering process comprising: the application of at least one first room effect transfer function, the first transfer function being specific to each input signal, and the application of at least one second room effect transfer function, the second transfer function being common to all input signals. The method is such that it comprises a step of weighting at least one input signal with a weighting factor, said weighting factor being specific to each of the input signals.

Sound spatialization with room effect

A sound spatialization, with the application of at least one transfer function with room effect to at least one sound signal. This application amounts to multiplying, in the spectral range, spectral components of the sound signal by the spectral components of a filter corresponding to the transfer function, each spectral component of the filter having a temporal evolution in a time-frequency representation. In particular, the spectral components of the filter are especially ignored, for the above-mentioned multiplications of components, beyond a threshold frequency and after at least a given instant in said time-frequency representation.

Sound spatialization with room effect, optimized in terms of complexity

The invention concerns sound spatialization with multichannel encoding for binaural reproduction on two loudspeakers, the spatial encoding being defined by encoding functions associated with multiple encoding channels and the decoding by applying filters for binaural reproduction. The invention provides for an optimization as follows: a) obtaining a original set of acoustic transfer functions particular to an individual's morphology (HRIR;HRTF), b) selecting spatial encoding functions (g(&#x3b8;,&#x3c6;,n)) and/or decoding filters (F(t,n)), and c) through successive iterations, optimizing the filters associated with the selected encoding functions or the encoding functions associated with the selected filters, or jointly the selected filters and encoding functions, by minimizing an error (c(HRIR,HRIR*)) calculated based on a comparison between: the original set of transfer functions (HRIR), and a set of reconstructed transfer functions (HRIR*) from encoding functions and decoding filters, whether optimized and/or selected.

Optimization of binaural sound spatialization based on multichannel encoding

Processing of sound data encoded in a sub-band domain, for dual-channel playback of binaural or Transaural&#xae; type is provided, in which a matrix filtering is applied so as to pass from a sound representation with N channels with N&#x3e;0, to a dual-channel representation. This sound representation with N channels comprises considering N virtual loudspeakers surrounding the head of a listener, and, for each virtual loudspeaker of at least some of the loudspeakers: a first transfer function specific to an ipsilateral path from the loudspeaker to a first ear of the listener, facing the loudspeaker, and a second transfer function specific to a contralateral path from said loudspeaker to the second ear of the listener, masked from the loudspeaker by the listener's head. The matrix filtering comprises a multiplicative coefficient defined by the spectrum, in the sub-band domain, of the second transfer function deconvolved with the first transfer function.

Processing of sound data encoded in a sub-band domain

The invention concerns a method and a system for sound spatialization of a first set of not less than one of the audio channels encoded on of a number of frequency subbands (SBk) and decoded in a transformed domain (Fl, C, Fr, Sr, SI, Ife) into a second set of not less than two (Bl, Br) sound channels in the time domain, from modelling filters converted into a gain and a delay applicable in the transformed domain involving: filtering (A) through equalization, subband delay of the signal by applying at least one gain and one delay to generate from each of said encoded channels an equalized and delayed component; adding (B) a subset of equalized and delayed signals to create a number of filtered signals corresponding to not less than two; synthesizing (C) each of said filtered signals to obtain the second set of not less than two reproduction sound channels (Bl, Br) in the time domain.

Method and device for efficient binaural sound spatialization in the transformed domain

The invention concerns a process for joint synthesis and spatialization of multiple sound sources in associated spatial positions, including: a) a step of assigning to each source at least one parameter (p) representing an amplitude; b) a step of spatialization consisting in implementing an encoding into a plurality of channels, wherein each amplitude (p) is duplicated to be multiplied to a specialization gain (g), each spatialization gain being determined for one encoding channel (p) and for a source to be spatialized (S); c) a step of grouping (R) the parameters multiplied by the gains (P), in respective channels (p, . . . , p), by applying a sum of said multiplied parameters (p) on all the sources (S) for each channel (p), and d) a step of parametric synthesis (SYNTH(I), . . . , SYNTH(M)) applied to each of the channels (p).

Joint sound synthesis and spatialization

A method of comparison between pieces of information characterizing reference values and pieces of information characterizing current values of sound-reproducing systems of a system of (n) microphones mand (p) speakers hpfor the control of said sound-reproducing systems characterized in that: A: for each speaker hp, at least one sound signal S is sent on the speaker hp, for each microphone m, a piece of information hpmis retrieved, this piece of information characterizing the sound-reproducing system comprising the speaker hpand the microphone m, B: a reference matrix Qis saved, this reference matrix being constituted by all the pieces of reference information hpmobtained following the sending of the sound signal S, C: as soon as a comparison is to be made, the step A is run with a sound signal S' to obtain current information on a matrix Q, D: the matrices Q and Qare compared.

Method and device for comparing signals to control transducers and transducer control system

An audio-visual system is provided for bringing together a local scene and a remote scene. The audio-visual system includes several concatenated audio-visual modules, and feedback control and control means between the various modules. Each audio-visual module comprises an image sensing device and a sound pickup device of the local scene, and an image and sound recovery device of the remote scene in an image plane. The audio-visual modules are connected to a transmission network. The feedback control and control means ensures image and sound quality continuity on the image plane when the people being filmed or recorded pass in front of the various image and sound pickup devices of the scene concerned.

Modular audio-visual system to bring together a local scene and a remote scene

In order to reduce acoustic echo and restore stereophonic sound in a digital transmission system of sound signals on multiple transmission channels, between a local site and one or several remote sites, comprising several microphones and loudspeakers, the method consists in the following steps: computing a weighting factor to be applied to each microphone signal before emitting, based on two attenuation factors computed from the microphone and loudspeaker signals; transmitting on each transmission channel the linear combination of weighted microphone signals; computing a weighting factor to be applied to each loudspeaker signal; and emitting on the loudspeaker the linear combination of transmitted, weighted signals.

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Rennes, France

Marc Emerit