Telefonaktiebolaget Lm Ericsson (publ)

Patrik Sandgren

Anders K Eriksson

Tommy Falk

Stefan Bruhn

Anisse Taleb

Ingemar Johansson

Erlendur Karlsson

Bo Burman

Jerker Mattias Zetterlund

Anders Eriksson

A method relating to a video conference connecting a first terminal to a plurality of second terminals via a switching server is disclosed. The switching server receives a plurality of uplink video streams from the first terminal via a single transport path, and the switching server sends a downlink video stream based on the uplink video streams to each of the second terminals. The method involves the steps of collecting information relating to the use of each of the second terminals and determining an order between the uplink video streams based on the information. The method further involves the steps of generating instructions for the first terminal to adjust the plurality of uplink video streams based on the order, and informing the first terminal of the instructions. A switching server and a first terminal involved in the method are also disclosed.

Priority of uplink streams in video switching

A method of audio scene management in a teleconference or other group sound telecommunication is presented, in which teleconference at least a first transmitting party, a second transmitting party and a receiving party participates. The method comprises receiving of signals representing sound of the first transmitting party and sound of the second transmitting party. The method further comprises obtaining of measures of sound activity for the first and second transmitting parties, respectively and selecting a first angle and/or a second angle based on the obtained measures of sound activity. The method further comprises processing of the received signals into processed signals such that sound from the first transmitting party is experienced by the receiving party as emanating from the first angle while sound from the second transmitting party is experienced as emanating from the second angle, with respect to the receiving party. Finally signals representing the processed signals are outputted.

Methods and arrangements for group sound telecommunication

Conference bridge () for managing an audio scene comprising two or more participants, the conference bridge comprising a mixer () and several user channels (N). The conference bridge is arranged to continuously create a 3D positional audio environment signal for each participant as a listening participant, by rendering the speech of each participant as a 3D positioned virtual sound source and excluding the speech of the listening participant, and to distribute each created 3D positional audio environment signal to the corresponding listening participant. Further, the conference bridge is arranged to place the virtual sound source corresponding to each participant at the same spatial position relative the listening participant in every created 3D positional audio environment.

Common scene based conference system

An audio processing circuit includes a crosstalk cancellation circuit that is advantageously simplified for use in audio devices that have closely-spaced speakers. In particular, crosstalk filtering as implemented in the circuit assumes that the external head-related contralateral filters are time-delayed and attenuated versions of the external, head-related ipsilateral filters. With this assumption, the circuit's crosstalk filtering is configurable for varying audio characteristics, according to a small number of settable parameters. These parameters include configurable first and second attenuation parameters for cross-path signal attenuation, and configurable first and second delay parameters for cross-path delay. Optional sound normalization, if included, uses similar simplified parameterization. Further, in one or more embodiments, the audio processing circuit and method include or are associated with a defined table of parameters that are least-squares optimized solutions. The optimized parameter values provide wider listening sweet spots for a greater variety of listeners.

Apparatus and method for producing 3D audio in systems with closely spaced speakers

Signals of different channels are combined into one mono signal. A set of adaptive filters, preferably one for each channel, is derived in a respective filter adaptation unit. When an adaptive filter is applied to the mono signal it reconstructs the signal of the respective channel under a perceptual constraint. The perceptual constraint is a gain and/or shape constraint. The gain constraint allows the preservation of the relative energy between the channels while the shape constraint allows more stability by avoiding unnecessary filtering of spectral nulls. The transmitted parameters are the mono signal, in encoded form, and the parameters of the adaptive filters, preferably also encoded. The receiver reconstructs the signal of the different channels by applying the adaptive filters and possibly some additional post-processing.

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Stockholm, Sweden

Patrik Sandgren