Abstract: The present invention relates generally to network quality estimation using HTTP/2 push feature. When network quality estimation is required, a client web application requests a server to enter a probing mode. During the probing mode, the server pushes useful data to the application for the latter to perform the estimation. This avoids wasting bandwidth since the useful data are likely to be used by the application. Furthermore, during the probing mode, the server notifies the application of the push start and the push end of each pushed data. This is one using a web socket established with the application. This makes it possible to overcome the limitations of the application in accessing HTTP/2 features of a client browser. Based on the notifications, the application is able to perform accurate estimations.

Abstract: The invention relates to encapsulating tiled timed media data in a server and providing a timed media data bit-stream from encapsulated tiled timed media in a client device. The tiled timed media data comprises timed samples and each timed sample comprises a plurality of spatial subsamples. After having selected at least one spatial subsample from amongst the plurality of spatial subsamples of one of the timed samples, one tile track comprising the selected spatial subsample and one corresponding spatial subsample of each of the other timed samples is created for each selected spatial subsample. One composite track comprising at least one extractor identifying at least one of the created tile tracks is created. Each created track is independently encapsulated in at least one media segment file.

Abstract: A method of processing video data comprising subdividing a video stream into image portions, encoding the image portions with high resolution in respective encoded video streams and reassembling a selection of encoded video streams in order to display a region of interest with high resolution. Embodiments of the invention provide high resolution display of specific region of interest without a priori knowledge of the position of the region of interest.

Abstract: The present invention provides a method for streaming data corresponding to a given video, each frame of the video being divided into n spatial tiles, n being an integer, in order to create n independent video sub-tracks. The method comprises: transmitting, by a server, a description file to a client device, said description file including data about the spatial organization of the n video sub-tracks and at least n URLs respectively designating each video sub-track, selecting by the client device one or more URLs according to one Region Of Interest chosen by the client device or a client device's user, receiving from the client device, by the server, one or more request messages for requesting a resulting number of video sub-tracks, each request message comprising one of the URLs selected by the client device, and transmitting to the client device, by the server, video data corresponding to the requested video sub-tracks, in response to the request messages.

Abstract: The invention concerns a method of notifying control information to a congestion control mechanism in charge of controlling data segments sending rate of a server towards a client. The control information includes loss events where a loss event corresponds to one or more data segments lost. The method comprises a step of receiving data segments into a reception buffer at the client, a step of detecting loss events from the received data segments and a step of notifying the congestion control mechanism with a number of loss events that is dependent on the number of detected loss events and a measure of criticality related to the reception of the data segments by the client. The measure of criticality can be derived from the filling level of the reception buffer, the reception of data segments being in a critical state when the reception buffer is experiencing overflow or underflow conditions.

Abstract: A method of encapsulating data units of at least one encoded video frame into a data stream, said data units representing frame portions of the video frame, wherein said data stream is associated with an ordering information indicating the compliance of the order of the data units with a nominal data unit decoding order. Embodiments of the invention provide flexible transmission with robust and flexible decoders.

Abstract: A method of sending a data stream of video images between a server and at least one client device in a communication network, employing a rate setting for the sending of data over the communication network, the method comprising the following steps: obtaining (910) an item of information Pc representing a speed of variation over time for a rate setting, said item of information depending on at least one characteristic of the state of the traffic over the communication network, comparing (920) said item of information Pc so obtained with a scheduled time Ev for a set of video image data to send, adapting (930) the rate setting delivered by the server on the basis of at least the result of the comparing step, compressing said set of video image data to send using a compression mode which depends on the adapted rate setting, sending said set of video image data so compressed.

Abstract: A video consisting of data organized in the form of a plurality of images is transmitted in a communication network. The method comprises a step of coding images with motion compensation, which consists in compressing the images of the video and in creating dependencies between compressed images, a step of scheduling the transmission of packets representing the compressed images, which consists in sending the compressed images over the network in a selected order, and a step of controlling the rate of the video. At least one of reconsidering the selected order of sending already compressed but not yet transmitted images and deleting at least one compressed image is performed at the time of coding a new image. Furthermore, the dependencies between the new image to be compressed and the compressed images are selected by taking into account the reconsidered sending order at the time of coding the new image.

Abstract: The method of computing the available space in a packet for data stream transport comprises: a step of determining the requirements of each module of a data stream manager, for space in the packet for at least two types of header and/or extension data required by each protocol and/or service used by said module, a step of determining a maximum space requirement in the packet to meet all these requirements, by implementing different rules for combining space requirements for the different types of data and a sum of the combined requirements for the different types of data and a step of computing a difference between the space of the packet and the maximum space requirement in the packet in order to determine the available space for data stream transport.

Abstract: The present invention relates to a method and device for generating a description file about a video sequence at a server device for a client device, to retrieve a video segment and containing a region of interest. The method comprising for each video segment, determining a time interval during which the detected region of interest is spatially included in a same frame region in the video sequence; and generating a description file comprising spatial information describing the frame region and temporal information describing a duration at least equal to the determined time interval.

Abstract: A method for adapting error protection in a communication network includes: a step of determining periods of time that are homogeneous as regards the distribution law of losses over the network, a step of classifying the homogeneous periods of time into at least two classes, on the basis of information representing losses over the network and/or representing a corresponding level of protection, during these periods of time, a step of determining a probability of alternation between two of said classes, and a step of selecting a protection strategy on the basis of said probability of alternation. A method of detecting transition between two states of a communication network corresponding to different loss rates of sent data includes: a step of determining a probability of transition, and a step of determining the existence of a transition on the basis of said probability.

Abstract: The access method comprises the following steps: i) receiving a request coming from a user for accessing at least one digital document, said request comprising an identifier (303) designating the digital document and an identifier (304) designating said user; ii) searching locally for at least one collection (C1) containing the identifier (303) of the document and the identifier (304) of the user, each collection (C1, C2) being stored locally in response to a positive verification with regard to at least one condition agreeing to supply the document according to at least one access right linked to the collection; and iii) in the case of a positive search, supplying said corresponding document (303) to said user (304) thus designated.

Abstract: A method of distributing digital data implemented in a telecommunications system that has at least one holding server device able to hold digital data and to receive at least one request for supplying said digital data, at least one client device able to request the digital data of the holding server device, and at least one replication server device able to store a replica of the digital data of the holding server device and to supply the replica digital data to the client device.

Abstract: The method of transmitting data packets associated with an importance level comprises a step (305) of estimating available rate on the network. In case a variation is detected in estimated available rate greater than a first predetermined value, determination is made (309-317) of whether there is an increase in the round trip time on said network that is greater than a second predetermined value. If yes, the data packets are transmitted (319-325) at a rate lower than the estimated available rate. In embodiments, in case a variation is detected in estimated available rate greater than a first predetermined value and before the step of detecting an increase in the round trip time, a step (307) is carried out of transmitting packets of lower importance level than the average of said importance levels by using the current estimated available rate and the round trip time is determined on the basis of the sending of those packets.

Abstract: The invention concerns a method of correcting errors in a data stream of at least one image, implemented in a data reception device, said at least one image being cut up into image portions, said stream being coded by image portion and divided into data packets, the method comprising a step of detecting at least one lost data packet and being characterized in that it comprises the following steps: determining a strategy for cutting up said at least one image into image portions, determining, according to the determined cutting-up strategy, an item of information representing the reconstruction quality of data included in said at least one lost packet by an error correcting method, adapting said error correcting method according to the determined item of information representing the reconstruction quality, and applying the adapted error correcting method to the adapting step to reconstruct the data included in said at least one lost packet.

Abstract: This method allows the transmission of coded data representing a sequence of digital images. A predetermined quantity of this data is stored in a buffer before transmission over a communication network. The method comprises a step of determining a subset of data in the buffer to be transcoded, as a function of at least one quantity representing the bandwidth available for the communication network.

Abstract: An encoder extracts motion vectors from a frame I(t?1) preceding the frame I(t) being encoded and processes them to create an estimated motion vector field I(t) for the frame being encoded. A minimised difference between the motion vector field of the frame being encoded and the estimated motion vector field is used to generate transform parameters, which are transmitted to the decoder as auxiliary information along with the usual motion prediction information. The decoder receives the transform parameters. The decoder also creates an estimated motion vector field I(t) for based on a preceding frame I(t?1) and applies the transform parameters to the estimated motion vector field to obtain missing motion vectors. The motion vector field rebuilt using the reconstructed missing motion vectors is used for subsequent error concealment/decoding/displaying.

Abstract: A method of processing a coded data stream of a current image on a receiving device, the data stream being organized into packets, comprises a step of detecting a lost packet. It further comprises: a step of estimating, prior to the decoding of the current image, an importance criterion of the lost packet, the importance criterion being determined from at least one decoded preceding image; and a step of requesting retransmission of the lost packet depending on said estimated importance criterion. Use in particular for improving the transmission of a video.

Abstract: The invention concerns a method of notifying control information to a congestion control mechanism in charge of controlling data segments sending rate of a server towards a client. The control information includes loss events where a loss event corresponds to one or more data segments lost. The method comprises a step of receiving data segments into a reception buffer at the client, a step of detecting loss events from the received data segments and a step of notifying the congestion control mechanism with a number of loss events that is dependent on the number of detected loss events and a measure of criticality related to the reception of the data segments by the client. The measure of criticality can be derived from the filling level of the reception buffer, the reception of data segments being in a critical state when the reception buffer is experiencing overflow or underflow conditions.

Abstract: To predict the transmission error rate in a stream of data packets transmitted between a server and at least one client in a communication network: the server sends at least one group of packets to the client; the client calculates a plurality of items of statistical information on the group of packets and transmits them to the server; the server analyzes the items of statistical information so as to obtain a network stability indicator; and the server calculates a prediction of the transmission error rate on the basis of the network stability indicator.