Abstract: The invention comprises a videoconference server (2) comprising: —an audio processing module (9) configured to, ?calculating an average audio processing delay of processing audio packets intended to the second client device, in order that the second client device may synchronize a received video packet with the associated received audio packet, —a video router (10) configured to: ?duplicate the video packet and temporarily store the duplicated video packet, ?receive a retrieving request from the second client device (4) for retrieving a lost video packet, ?retrieving the duplicated video packet associated with the identification information in the video buffer (17).

Abstract: The invention comprises a videoconference server (2) comprising:—an audio processing module (9) configured to, o calculating an average audio processing delay of processing audio packets intended to the second client device, in order that the second client device may synchronize a received video packet with the associated received audio packet,—a video router (10) configured to: duplicate the video packet and temporarily store the duplicated video packet, o receive a retrieving request from the second client device (4) for retrieving a lost video packet, o retrieving the duplicated video packet associated with the identification information in the video buffer (17).

Abstract: A method and a resource broker are provided to control a conference session. The resource broker receives, from a conference controller, a message requesting to set up a conference communication for a participant. The message indicates whether a terminal of the participant supports selective forwarding. The resource broker verifies the availability of local selective forwarding and multipoint control resources. Based on the capabilities of the terminal and based on local resource availability, a reply is sent to the conference controller, indicating that the conference communication should be set up in selective forwarding or multipoint control mode, using local resources or resources of a network cloud. When a new participant is added or when a monitoring agent reports a change of availability of the local resources, the conference communication may be moved between the network cloud and the local resources, or change between selective forwarding and multipoint control modes.

Abstract: A method and a resource broker are provided to control a conference session. The resource broker receives, from a conference controller, a message requesting to set up a conference communication for a participant. The message indicates whether a terminal of the participant supports selective forwarding. The resource broker verifies the availability of local selective forwarding and multipoint control resources. Based on the capabilities of the terminal and based on local resource availability, a reply is sent to the conference controller, indicating that the conference communication should be set up in selective forwarding or multipoint control mode, using local resources or resources of a network cloud. When a new participant is added or when a monitoring agent reports a change of availability of the local resources, the conference communication may be moved between the network cloud and the local resources, or change between selective forwarding and multipoint control modes.

Abstract: A method for generating an immersive video of a plurality of persons in a computer server, the method comprising: —receiving a plurality of video streams on a plurality of video channels from a plurality of client devices, each video stream including a silhouette of a person; —extracting the person's silhouette from each incoming video stream to generate a filtered video stream representing only the silhouette of the person; —generating a video stream of a virtual scene comprising a plurality of—the silhouettes extracted from the plurality of filtered video streams the method further comprising receiving silhouette data carried on a metadata channel from a client device in addition to the video stream, the silhouette data representing a position of a face of the person within a frame of the video stream; —analyzing the silhouette data performing the silhouette extraction as a function of the silhouette data analyzed.

Abstract: A method for allocating a video conferencing task within a computer network comprising a plurality of candidate processing devices, the method comprising: for each of the candidate processing devices: determining a topological score, the topological score being a function of at least one end-to-end delay between a pair of participating endpoints through the candidate processing device; for each candidate processing device within at least a subset of the candidate processing devices: determining an availability score, the availability score being a function of an available processing capacity of the candidate processing device; selecting a preferred processing device among the candidate processing devices as a function of the topological scores and of the availability scores, and allocating the video conferencing task to the preferred processing device.

Abstract: A method for allocating a video conferencing task within a computer network comprising a plurality of candidate processing devices, the method comprising: for each of the candidate processing devices: determining a topological score, the topological score being a function of at least one end-to-end delay between a pair of participating endpoints through the candidate processing device; for each candidate processing device within at least a subset of the candidate processing devices: determining an availability score, the availability score being a function of an available processing capacity of the candidate processing device; selecting a preferred processing device among the candidate processing devices as a function of the topological scores and of the availability scores, and allocating the video conferencing task to the preferred processing device.

Abstract: A method for generating an immersive video of a plurality of persons in a computer server, the method comprising:—receiving a plurality of video streams on a plurality of video channels from a plurality of client devices, each video stream including a silhouette of a person;—extracting the person's silhouette from each incoming video stream to generate a filtered video stream representing only the silhouette of the person;—generating a video stream of a virtual scene comprising a plurality of—the silhouettes extracted from the plurality of filtered video streams the method further comprising receiving silhouette data carried on a metadata channel from a client device in addition to the video stream, the silhouette data representing a position of a face of the person within a frame of the video stream;—analyzing the silhouette data performing the silhouette extraction as a function of the silhouette data analyzed.

Abstract: The present invention relates to a method for recognizing gestures within a two-dimensional video stream for use in conference situations and the like, comprising the step of performing a skin-recognition within a screen of the video stream for recognizing skin parts, identifying at least one body part within the recognized skin parts, monitoring a state of at least one predefined screen area in respect to the at least one body part, and providing a control signal indicating a detected gesture upon detection of a change of state. The present invention further relates to a gesture detector adapted to perform the above method, a presentation system comprising the above gesture detector and a video camera device comprising a video camera and the above gesture detector.

Abstract: A canceller splits a signal, transmitted from a near end terminal (ET) to a far ET, into a sub-sampled signal corresponding to a higher frequency sub-band of the signal transmitted to the far ET, and a sub-sampled signal corresponding to a lower frequency sub-band of the signal transmitted to the far ET; and splits a signal received from a far ET into a sub-sampled signal corresponding to a higher frequency sub-band of the signal received from the far ET, and a sub-sampled signal corresponding to a lower frequency sub-band of the signal received from the far ET. The canceller includes a first adaptive filter for filtering the sub-sampled signal corresponding to the lower frequency sub-band, a second adaptive filter for filtering the sub-sampled signal corresponding to the higher frequency sub-band, and controls the adaptation of the first and second adaptive filters so that these two adaptations are never simultaneous.

Abstract: The present invention relates to a method for recognizing gestures within a two-dimensional video stream (3) for use in conference situations and the like, comprising the step of performing a skin-recognition within a screen (4) of the video stream (3) for recognizing skin parts (13), identifying at least one body part (19, 20) within the recognized skin parts (13), monitoring a state of at least one predefined screen area (23) in respect to the at least one body part (19, 20), and providing a control signal indicating a detected gesture upon detection of a change of state. The present invention further relates to a gesture detector (5) adapted to perform the above method, a presentation system (1) comprising the above gesture detector (5) and a video camera device (24) comprising a video camera (2) and the above gesture detector (5).

Abstract: The proposed echo canceller comprises:—an adaptive filter for receiving a signal affected by an echo, and for supplying a filtered signal that is an estimate of the echo;—a subtractor for subtracting this estimate from the received signal and supplying a residual signal;—means for detecting (7, 8) a ring back tone in said residual signal;—means for blocking (9) the received signal and replacing it by a locally generated ring back tone if a ring back tone is detected in the received signal;—a timer to determine a time period;—and means (11-17) for, during said time period, replacing the residual signal by some synthetic comfort noise when there is no ring back tone.

Abstract: A canceller splits a signal, transmitted from a near end terminal (ET) to a far ET, into a sub-sampled signal corresponding to a higher frequency sub-band of the signal transmitted to the far ET, and a sub-sampled signal corresponding to a lower frequency sub-band of the signal transmitted to the far ET; and splits a signal received from a far ET into a sub-sampled signal corresponding to a higher frequency sub-band of the signal received from the far ET, and a sub-sampled signal corresponding to a lower frequency sub-band of the signal received from the far ET. The canceller includes a first adaptive filter for filtering the sub-sampled signal corresponding to the lower frequency sub-band, a second adaptive filter for filtering the sub-sampled signal corresponding to the higher frequency sub-band, and controls the adaptation of the first and second adaptive filters so that these two adaptations are never simultaneous.

Abstract: The proposed echo canceller comprises:—an adaptive filter for receiving a signal affected by an echo, and for supplying a filtered signal that is an estimate of the echo;—a subtractor for subtracting this estimate from the received signal and supplying a residual signal;—means for detecting (7, 8) a ring back tone in said residual signal;—means for blocking (9) the received signal and replacing it by a locally generated ring back tone if a ring back tone is detected in the received signal;—a timer to determine a time period;—and means (11-17) for, during said time period, replacing the residual signal by some synthetic comfort noise when there is no ring back tone.

Abstract: The invention concerns a method of controlling an adaptation of a filter, and a controller and a computer program product to execute this method. The filter is an adaptive finite impulse response (=FIR) filter for modelling an echo path impulse response for echo cancellation in a telecommunications connection between a first terminal providing a near-end signal at a first end of the telecommunications connection and a second terminal providing a far-end signal at another end of the telecommunications connection. In a multi-windowing scheme, a plurality of filter segments and segments of the far-end signal is determined in the time domain. An energy level associated to an individual segment of the far-end signal is compared with an energy level associated to a sample of the near-end signal. In dependence on the result of the comparison of the energy levels, the adaptation of an individual filter segment associated to the individual segment of the far-end signal is enabled or inhibited.

Abstract: The invention concerns a method of controlling an adaptation of a filter, and a controller and a computer program product to execute this method. The filter is an adaptive finite impulse response (=FIR) filter for modelling an echo path impulse response for echo cancellation in a telecommunications connection between a first terminal providing a near-end signal at a first end of the telecommunications connection and a second terminal providing a far-end signal at another end of the telecommunications connection. In a multi-windowing scheme, a plurality of filter segments and segments of the far-end signal is determined in the time domain. An energy level associated to an individual segment of the far-end signal is compared with an energy level associated to a sample of the near-end signal. In dependence on the result of the comparison of the energy levels, the adaptation of an individual filter segment associated to the individual segment of the far-end signal is enabled or inhibited.

Abstract: A device is dedicated to encrypting/decrypting data in a communication equipment able to exchange data with another data equipment of an equivalent type via at least one communication network entailing modulation/demodulation. This device comprises processing means adapted i) in the event of setting up a call between their called equipment and a calling equipment with a view to transmitting data to generate a first message to the calling equipment containing in a non-standard facilities field first data for determining a primary encryption key then to determine that primary encryption key as a function of the first data and ii) in the event of reception from the calling equipment of a second message containing (possibly in a field of the message) second data representative of its ability to encrypt data to be transmitted and then of encrypted data to decrypt the received encrypted data by means of the primary encryption key.