Vantrix Corporation

Yves Lefebvre

Sebastien Cote

Francis Roger Labonte

A method of data streaming from an encoder to a decoder is provided. The method includes establishing a connection from said encoder to said decoder; acquiring measurements characterizing said connection; estimating transmittance variation of said connection according to said measurements; determining a permissible encoding rate of said encoder compatible with the transmittance variation; determining a set of metrics characterizing said connection; receiving, at said encoder, a signal from a source; instructing said encoder to encode said signal according to said permissible encoding rate; selecting a set of notification-display intervals each corresponding to a respective metric among said set of metrics; and superimposing on said signal, during said notification-display intervals, corresponding indications of said metrics. A corresponding system is also provided.

Informative data streaming server

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 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.

A server for data streaming encodes multimedia signals at bit rates compatible with a connection of time-varying conditions and informs a client receiving a multimedia signal of changing bit rates and causes of change. The server supports several clients and includes a flow controller and at least one encoder. The flow controller derives metrics from measurements to determine a permissible transmission rate from the server to each active client. An encoder adapts individual transmission rates of signals according to respective permissible transmission rates. An overlay module, coupled to a multimedia signal source, the flow controller, and an encoder, superimposes informative insertions indicating permissible transmission rates and associated metrics on a multimedia signal to inform a client of changing transmission rates and causes of change. An informative insertion has a predefined duration and is sent either periodically or following a substantial change of network conditions.

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Sherbrooke, Canada

Yves Lefebvre