Orange

France Telecom

Grégory Pallone

Marc Emerit

David Virette

Julien Faure

Rozenn Nicol

Alexandre Guerin

Jean-Philippe Thomas

Arnault Nagle

Patrice Houze

Stéphane Louis Dit Picard

Thomas Joubaud

Clément Gaultier

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

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 relates to a method of tracking the position of the bust of a user on the basis of a video image stream, said bus comprising the user's torso and head, the method comprising the determination of the position of the torso on a first image, in which method a virtual reference frame is associated with the torso on said first image, and in which method, for a second image, a new position of the virtual reference frame is determined on said second image, and, a relative position of the head with respect to said new position of the virtual reference frame is measured by comparison with the position of the virtual reference frame on said first image, so as to determine independently the movements of the head and the torso.

Method of tracking the position of the head in real time in a video image stream

A conference bridge of a conference system having a plurality of conference stations, the bridge comprising: reception means for receiving dual-channel audio signals coming from the conference station; determination means for determining at least one processing function per conference station of the conference system; application means for applying respective weighing functions to the received dual-channel signals; build-up means for building up one hybrid dual-channel signal for forwarding per conference station by means for summing a portion of the process dual-channel audio signals; and forwarding means for forwarding the respective hybrid dual-channel audio signal to each of the various conference stations of the conference system. A method of forwarding a spatialized audio scene and implemented by a conference bridge is also disclosed.

Forwarding an audio signal in an immersive audio conference system

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).

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Trelevern, France

Grégory Pallone