Abstract: A control server is intended for controlling content distribution to peers coupled to a communication network which comprises at least one content serving means (CNS, N1-N3) storing contents. This control server is arranged i) for transmitting messages to these peers to inform them that a content will soon be distributed by means of an identified multicast session, and to identify content parts that have been respectively associated to them, and ii) for ordering at least one content serving means to initiate this identified multicast session to transmit the content to the peers, in order those having decided to listen to the multicast session store the content parts that have been identified into their respective messages.

Abstract: The invention concerns a method for assigning parts of multimedia files to distributed storage devices, the number of said devices being an integer n, characterized in that it comprises the following steps: a step consisting in dividing each multimedia file in windows, which represent data for contiguous playback of a given duration; a step consisting, for each multimedia file, in determining a number k so that any original window of file can be recovered from any k distinct symbols; a step consisting, for each window of each said multimedia files, in assigning n corresponding symbols to said devices, one to each device, the n distinct symbols being created using erasure coding; and a step consisting in partially or totally filling the storage memory left on each device after said first steps with prefix windows of said multimedia files.

Abstract: A method is intended for disseminating content data in a peer-to-peer mode between peers connected to at least one communication network. This method comprises the steps of: i) making peers exchange neighboring information between them to build a bipartite peer overlay comprising a first group, comprising peers having a complete content to be disseminated, and a second group, comprising peers having not this content or only a part of it and having links therebetween, ii) disseminating the data defining the content (and preferably encoded with erasure correcting codes) from peers of the first group to first peers of the second group according to the bipartite peer overlay, iii) disseminating the data received by the first peers to other peers of the second group according to the bipartite peer overlay, and iv) updating the bipartite peer overlay when a peer of the second group has fully completed the content.

Abstract: A method dedicated to the management of data transmission in peer to peer mode between peers that can connect to a communication network, each transmission being carried out by a peer, following the reception of a request from another peer, according to a selected reciprocity mechanism. When a peer wants to receive from another peer N blocks of data according to a first priority level Xk selected in a set of at least two different priority levels, in assigning to this peer an exchange value equivalent to a number M of blocks of data to be transmitted to at least one other peer according to a second priority level Xk? selected in this set, M being equal to N*mkk?, where mkk? is a predetermined value function of the first Xk and second Xk? selected priority levels.

Abstract: The present invention concerns a method of transferring content from a first communication device to a second communication device in a communication network, comprising the following steps: defining a first probability, according to which a content can be encoded; defining a second probability, according to which a content can be chosen; upon request of content from said second communication device to said first communication device: encoding content with another content according to said first probability, said content being chosen with said second probability, and transferring content z=x XOR y from said first communication device to said second communication device, or according to probability 1-pe transferring unencoded content x from said first communication device to said second communication device.

Abstract: In a method and an apparatus for navigating through subtitles of an Audio Video data stream an address information of one or more played back data units is stored together with the subtitle information of said played back data units during play back of said data units. One or more of said stored subtitle information can be displayed. Following the selection of one of said displayed subtitle information the stored address information of the data unit corresponding to the selected subtitle information is retrieved and the corresponding data unit is accessed using said retrieved address information. Playing back the accessed data unit conveniently allows to watch and listen to a scene including subtitles again, e.g. by a few clicks on the remote control.

Abstract: The invention relates to a method of transmitting digital data packets protected by error correction packets and more precisely the manner of inserting these correction packets into the data packet stream so as to increase the correction effectiveness of the error correction method while limiting the latency introduced into the transmission. The packets are set out in matrix form, error packets are computed on lines and columns and are inserted regularly into the stream at a sufficient distance from the data packets that they protect.

Abstract: A method of managing auxiliary programs broadcast with main programs in a digital data stream, wherein the method is implemented by a receiver, involving receiving several digital data streams including the aforementioned digital data stream, detecting data identifying all the auxiliary programs contained in said digital data stream, extracting all the auxiliary programs identified in the stream, and storing all of the auxiliary programs identified and extracted from the digital data stream, wherein the extraction is followed by analyzing execution commands associated with the extracted auxiliary programs.

Abstract: A method is intended for disseminating content data in a peer-to-peer mode between peers connected to at least one communication network. This method comprises the steps of: i) making peers exchange neighboring information between them to build a bipartite peer overlay comprising a first group, comprising peers having a complete content to be disseminated, and a second group, comprising peers having not this content or only a part of it and having links therebetween, ii) disseminating the data defining the content (and preferably encoded with erasure correcting codes) from peers of the first group to first peers of the second group according to the bipartite peer overlay, iii) disseminating the data received by the first peers to other peers of the second group according to the bipartite peer overlay, and iv) updating the bipartite peer overlay when a peer of the second group has fully completed the content.

Abstract: A network re-encoding device is intended for re-encoding encoded symbols to be transmitted to at least one communication equipment connected to a network. This network re-encoding device comprises a re-encoding means arranged for re-encoding output nodes, defined by LT code symbols representative of encoded symbols and representative respectively of the results of XOR Boolean operation between input nodes defining decoded symbols whose values have to be discovered and to which they are linked into a Tanner graph, by combining chosen input node and/or output node having known values, in order to produce new LT code symbols defining generated output nodes ready to be transmitted.

Abstract: Methods for transmitting first packets encapsulated in second packets in a transmission system in which part of the first packets contain a first timing reference for synchronization of a receiver clock and at least part of said second packets contain a second timing reference for reducing transmission jitter of the second packets at the receiver is described. This method provides, at the transmitter, collecting first packets, determining whether a collected first packet contains a first timing reference and triggering transmission of a second packet encapsulating collected first packets including the first packet containing the first timing reference in response to a positive determination.

Abstract: The invention relates to a method for controlling of the display of audio-visual program by a receiver provided with means of receiving and recording audio-visual programs. The method comprises a step of recording a first program selected by the user; and subsequent to an action by the user to display the recorded program, a step of playback a program of a second type pre-recorded in the recording means (this program being for example of an advertising type), and a step which consists in displaying the second type program before the end of the first program display for a time interval stored in the receiver, the display of the first program being conditional to the display of the second-type program. The invention is characterized in that it comprises an improvement, whereby the receiver keeps an account of the duration of display of programs of the second type and authorizes unconditionally the display of programs after a certain duration.

Abstract: A method dedicated to the management of data transmission in peer to peer mode between peers (P1-P4) that can connect to a communication network (R), each transmission being carried out by a peer (P1), following the reception of a request from another peer (P2), according to a selected reciprocity mechanism. This method consists, when a peer (P2) wants to receive from another peer (P1) N blocks of data according to a first priority level Xk selected in a set of at least two different priority levels, in assigning to this peer (P2) an exchange value equivalent to a number M of blocks of data to be transmitted to at least one other peer (P1) according to a second priority level Xk? selected in this set, M being equal to N*mkk?, where mkk? is a predetermined value function of the first Xk and second Xk? selected priority levels.

Abstract: A network re-encoding device is intended for re-encoding encoded symbols to be transmitted to at least one communication equipment connected to a network. This network re-encoding device comprises a re-encoding means arranged for re-encoding output nodes, defined by LT code symbols representative of encoded symbols and representative respectively of the results of XOR Boolean operation between input nodes defining decoded symbols whose values have to be discovered and to which they are linked into a Tanner graph, by combining chosen input node and/or output node having known values, in order to produce new LT code symbols defining generated output nodes ready to be transmitted.

Abstract: The present invention concerns a transmitter and a receiver and a method thereof for permitting a receiver to reconstruct a stream at a constant bit rate. In particular it concerns a method for transmitting first packets encapsulated in second packets in a transmission system, comprising the steps, at the transmitter, of collecting a predetermined number of the first packets, and triggering transmission of the second packet encapsulating the collected first packets, the second packet comprising a timestamp for each one of the first packets.

Abstract: The invention concerns a method for securing a data packet stream involving the following steps: arranging the packets to be sent in a matrix of D rows and L columns; to each row and each column of the matrix, applying an error correction function, the result of which is a correction packet; then sending the resulting correction packets in addition to the data packets. The invention also concerns a method for reconstructing lost packets in a data packet stream involving the following steps: arranging the received packets in a matrix of D rows and L columns, taking their sequence number into account; to each row and each column of the matrix containing at least one lost packet, applying a function for reconstructing missing packets using the received packets and the correction packet corresponding to the row or to the column. The invention also concerns the devices implementing these methods.

Abstract: A method is dedicated to data transmission in peer-to-peer mode between peers (P1-P4) being able to connect by means of communication equipment (E1-E4) to a first communication network (R1) providing access to the Internet and to a second communication network (R2). This method consists, when a communication application of the peer-to-peer type (A) running in a first peer (P1) must transmit data to at least one second peer (P3) in which the same communication application (A) runs, i) in choosing one of the first (R1) and second (R2) networks according to at least one criterion chosen to perform its transmission, and ii) in connecting the first peer (P1), via its equipment (E1), to the network chosen to transmit the data in peer-to-peer mode to the second peer (P3), via this chosen network.

Abstract: The present invention relates to a method for the distribution of multimedia content, comprising: a first step comprising a download in “push” mode of a multimedia content, in a partial way, from a content server to a client device, and a second step comprising a download of the missing elements of said multimedia content in “pull” mode via a “peer to peer” mechanism from a second client device, and in that the multimedia content can be reconstituted with n+p blocks, n and p being non-null natural integers, n blocks being downloaded during said first step and p blocks being downloaded during the second step, the multimedia content being exploitable only after reception of n+p blocks.

Abstract: Method for transmission of images comprising: a reception of a source digital image comprising padding lines and data lines, the data lines comprising ancillary data and video data. In order to optimise the use of a transmission channel, the method also comprises: a filtering of padding lines to form sets of data comprising ancillary data and video data; a cutting of the sets into fragments of a maximum fragment length that is a function of a maximum transport packet length; an insertion of at least one image number in each of the fragments, each of the ancillary data and video data being associated with this number; an insertion of fragments into transport packets; and a transmission of the transport packets according to an internet protocol. The invention also relates to a corresponding method for reception.

Abstract: The invention concerns a solution for detecting conditions of dearth and overflow of a client input buffer to a real time content distribution. Said detection is performed upstream of clients through a dynamic estimation of the fill factor of the input buffers of said clients. Thus, it is possible to predict the occurrence of dearth or overflow situations and to take actions such as inserting stored video sequences or storing queueing packets.