Vantrix Corporation

Francis Roger Labonte

Sebastien Cote

Yves Lefebvre

Stéphane Coulombe

Richard Elliott Norton

Mario Joseph Leo Claude Lavalliere

Joseph Leo Lavalliere

A system and methods for adapting streaming data for transmission over a connection of time-varying capacity are disclosed. A streaming server individually adapts transmission rates of signals directed to subtending clients according to measurements characterizing connections from the streaming server to the clients. The measurements may relate to characteristics such as transfer delay, data-loss fraction, and occupancy level of a buffer at a client's receiver. A flow controller associated with the streaming server derives metrics from measurements taken over selected time windows to determine a permissible transmission rate from the server to each active client. Metrics related to a specific characteristic may include a mean value over a moving window as well as short and long term tendencies of respective measurements. An adaptable encoder at the streaming server encodes signals to meet permissible transmission rates.

Flow-rate adaptation for a connection of time-varying capacity

A device and method of controlling bitrate in video coding of a sequence of frames including series of Inter frames separated by Intra frames, wherein the coded frames are validated in a video buffering device prior to transmission of the coded frames and wherein the method comprises: measuring frame complexity in the sequence of frames; for each Inter frame, calculating a target buffer level of the video buffering device in relation to a distance between the Inter frame and a next Intra frame; for each Inter frame, calculating a target frame size in relation to the distance between the Inter frame and the next Intra frame, the measured frame complexity, a current buffer level of the video buffering device and the calculated target buffer level of the video buffering device; and using the calculated target frame size to control bitrate in video coding of the sequence of frames.

Buffer based rate control in video coding

A method and system are disclosed for adapting the media contained in a multimedia messaging service (MMS) message, which may include a presentation, into a single media format such as an audio/video file or stream by creating a logical timeline from information found in the presentation, creating an adaptation pipeline from the logical timeline, and executing the adaptation pipeline.

Method and system for multimedia messaging service (MMS) to video adaptation

A method of data streaming from an encoder to a decoder through a time-varying connection, is disclosed. The method includes associating an encoding coefficient with said time-varying connection, the encoding coefficient determining a flow rate at an output of said encoder; defining a performance metric of the time-varying connection; defining an acceptance interval of the performance metric having a lower bound and an upper bound; acquiring a set of performance measurements of the time-varying connection over a time window at a current encoding coefficient; determining a current value of the metric of the time-varying connection according to the set of measurements; determining a preferred encoding coefficient according to the current value of the metric; and modifying the current encoding coefficient based on the current value of the metric and the acceptance interval to attain the preferred encoding coefficient. A corresponding streaming server and system for data streaming are also provided.

Data streaming through time-varying transport media

Methods of data streaming from an encoder to a decoder through a connection subjected to time-varying conditions are disclosed. The connection is assigned a nominal flow rate and an encoding coefficient associated with the connection modifies the nominal flow rate to determine a permissible flow rate compatible with a time-varying state of the connection. Multiple performance characteristics are associated with the connection and corresponding sets of performance measurements taken over adaptively selected time windows are acquired. Performance metrics having one-to-one correspondence to the performance characteristics are determined and compared with lower bounds and upper bounds of respective predefined acceptance intervals. A current encoding coefficient is computed as a function of the performance metrics and used to determine the permissible flow rate. The encoder's configuration is adapted to produce an encoded signal which maximizes signal fidelity under the constraint of the permissible flow rate.

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Sherbrooke, Canada

Francis Roger Labonte