Abstract: A method of method of processing an image of a video sequence including a plurality of images, wherein the video sequence is divided into a sequence of consecutive subsets each including one or more consecutive images of the video sequence is provides, which includes: determining, among the consecutive subsets, a current subset that includes the image, upon determining that the image is a first image of the current subset to be processed, determining an analysis window corresponding to the current subset, wherein the analysis window includes a plurality of consecutive images of the video sequence, and includes at least one image of the current subset, and generating processing results for the image by performing a processing on the images of the analysis window.

Abstract: Disclosed is a method for processing a video stream including a set of images liable to contain a transition effect, the method including the following steps: detecting a fade-type transition effect within the set of images of the video stream and, where appropriate, calculating minimum and maximum brightnesses LMIN and LMAX for each image of the set of images containing the fade; estimating minimum and maximum brightnesses EMIN and EMAX for all of the images not containing the detected transition effect; determining minimum and maximum brightnesses SMIN and SMAX for a standard dynamic range; calculating minimum and maximum brightnesses TMIN and TMAX depending on the minimum and maximum brightnesses LMIN, LMAX, EMIN, EMAX, SMIN and SMAX calculated and determined beforehand; transmitting the calculated minimum and maximum brightnesses TMIN and TMAX with a view to dynamic range compression.

Abstract: Disclosed is a method for processing a video stream including a set of images liable to contain a transition effect, the method including the following steps: detecting a fade-type transition effect within the set of images of the video stream and, where appropriate, calculating minimum and maximum brightnesses LMIN and LMAX for each image of the set of images containing the fade; estimating minimum and maximum brightnesses EMIN and EMAX for all of the images not containing the detected transition effect; determining minimum and maximum brightnesses SMIN and SMAX for a standard dynamic range; calculating minimum and maximum brightnesses TMIN and TMAX depending on the minimum and maximum brightnesses LMIN, LMAX, EMIN, EMAX, SMIN and SMAX calculated and determined beforehand; transmitting the calculated minimum and maximum brightnesses TMIN and TMAX with a view to dynamic range compression.

Abstract: A method of processing an image divided into a plurality of pixel blocks which are processed according to a processing sequence is provided, which comprises, for a current pixel block: determining an application area comprising a set of pixels in blocks preceding the current block in the processing sequence; performing a gradient analysis on at least one pixel of the application area; selecting at least two intra prediction video coding modes among a plurality of intra prediction video coding modes usable for processing the current pixel block, wherein at least one of the selected intra prediction video coding modes is selected based on the gradient analysis; determining a plurality of predictors of the current pixel block based on the at least two selected intra prediction video coding modes; and generating a predictor of the current pixel block based on the determined plurality of predictors.

Abstract: A method, implemented by computer means, for digitally encoding multimedia content into one or more video streams for on-demand distribution to at least one receiving terminal, the method comprising the following steps: from a given set of profiles, each profile being characterized by a value of at least one encoding parameter, forming one or more ordered groups of profiles, it being possible for a same profile to be present in multiple groups, such that in each group, each profile and its immediate successor satisfy a first predetermined condition, and selecting from the formed groups at least one group of profiles satisfying a second predetermined condition.

Abstract: The invention concerns a method for encoding a multi-view video stream comprising at least two video sequences, comprising a step of motion information prediction for a square or rectangular block of a current picture of a current view from a list of candidate motion information predictors, a motion information predictor including at least a motion vector, and a step of entropic encoding of an item of information representative of the position of a selected motion information predictor in the list.

Abstract: A system is proposed for dynamic reduction of the entropy of a signal upstream to a data compression device. The signal includes a set of successive frames. The system has a filtering decision module that provides a setpoint value of filtering and a filtering module that filters the signal according to the setpoint value of filtering and gives a filtered signal to the data compression device. The system further includes a module for obtaining a piece of information on complexity for each frame of the signal. The filtering decision module is adapted to determining the setpoint value of filtering, for each frame of the signal, as a function inter alia of the piece of information on complexity.

Abstract: The invention concerns a method for encoding a video stream, an associated method for decoding a video stream, an associated encoder, an associated decoder and associated computer programs. The encoding method is directed to encoding a video stream comprising at least one video sequence, comprising, for the encoding of a square or rectangular block of a picture of a video sequence of the video stream, selecting a motion information predictor for the block from a list of candidate motion information predictors, and entropic encoding of an index representative of a position of the selected motion information predictor in the list.

Abstract: A system is proposed for dynamic reduction of the entropy of a signal upstream to a data compression device. The signal includes a set of successive frames. The system has a filtering decision module that provides a setpoint value of filtering and a filtering module that filters the signal according to the setpoint value of filtering and gives a filtered signal to the data compression device. The system further includes a module for obtaining a piece of information on complexity for each frame of the signal. The filtering decision module is adapted to determining the setpoint value of filtering, for each frame of the signal, as a function inter alia of the piece of information on complexity.

Abstract: The invention concerns a method for encoding a video stream, an associated method for decoding a video stream, an associated encoder, an associated decoder and associated computer programs. The encoding method is directed to encoding a video stream comprising at least one video sequence, comprising, for the encoding of a square or rectangular block of a picture of a video sequence of the video stream, selecting a motion information predictor for said block from a list of candidate motion information predictors, and entropic encoding of an index representative of a position of the selected motion information predictor in said list.

Abstract: The invention concerns a method for encoding a multi-view video stream comprising at least two video sequences, comprising a step of motion information prediction for a square or rectangular block of a current picture of a current view from a list of candidate motion information predictors, a motion information predictor including at least a motion vector, and a step of entropic encoding of an item of information representative of the position of a selected motion information predictor in the list.

Abstract: A real time encoder with bit rate constraint, of the type including: a capture buffer memory storing frames waiting to be processed; an encoding module receiving frames issued from the capture buffer memory and delivering compressed frames; an intermediate buffer memory, storing the compressed frames issued from the encoding module; and an emission buffer memory, storing data packets, resulting from the division of the compressed frames issued from the intermediate buffer memory, and emitting, with a controlled bit rate, the data packets on a communication channel. The encoder includes a control module, which dynamically adjusts the maximum size of the capture buffer memory, permitting the maximum size of the capture buffer memory to be temporarily increased as long as the emission buffer memory is not empty.

Abstract: A method is proposed for encoding/decoding an image having rectangular blocks of pixels. The image has a height of H blocks and a width of W blocks and is divided into vertical (or horizontal) bands of blocks having the height of H (or width of W) blocks. The method includes: obtaining N processors and M coprocessors, the M coprocessors distributed over S levels, N>1, S>0 and M>S; assigning the N processors Pi to N contiguous bands BPi having sizes of Ki blocks, 0?i?N?1 and ? i = 0 N - 1 ? ? K i = W ; for every level of coprocessors s, 0?s?S?1, assigning Ms coprocessors CPs,j to Ms contiguous bands having sizes of Qs,j blocks, with: ? j = 0 M s - 1 ? ? Q s , j = W ; managing sending of first, second and third start messages, and first and second verification messages to the processors and coprocessors, according to a predetermined set of rules.

Abstract: Method and apparatus for detecting transitions in a video sequence, which include detecting an abrupt transition including, for each image It?2k included in said video sequence and with a processing time rank t?2k: calculating a first distance D(It?k), between an image It?k and a reference image for said image It?k, which precedes said image It?k in the video sequence; calculating a second distance D(It?2k), between an image It?2k and a reference image for said image It?2k, which precedes said image It?2k in the video sequence; calculating a third distance D(It?3k), between an image It?3k and a reference image for said image It?3k, which precedes said image It?3k in the video sequence; calculating a criterion C? indicating whether said second distance D(It?2k) is significantly greater than the largest of the first and third distances, D(It?k) and D(It?3k); deciding, according to said criterion C?, on the belonging of the image It?2k to an abrupt transition.

Abstract: A method is proposed for encoding/decoding an image having rectangular blocks of pixels. The image has a height of H blocks and a width of W blocks and is divided into vertical (or horizontal) bands of blocks having the height of H (or width of W) blocks. The method includes: obtaining N processors and M coprocessors, the M coprocessors distributed over S levels, N>1, S>0 and M>S; assigning the N processors Pi to N contiguous bands BPi having sizes of Ki blocks, 0?i?N?1 and ? i = 0 N - 1 ? ? K i = W ; for every level of coprocessors s, 0?s?S?1, assigning Ms coprocessors CPs,j to Ms contiguous bands having sizes of Qs,j blocks, with: ? j = 0 M s - 1 ? ? Q s , j = W ; managing sending of first, second and third start messages, and first and second verification messages to the processors and coprocessors, according to a predetermined set of rules.

Abstract: A real time encoder with bit rate constraint, of the type including: a capture buffer memory storing frames waiting to be processed; an encoding module receiving frames issued from the capture buffer memory and delivering compressed frames; an intermediate buffer memory, storing the compressed frames issued from the encoding module; and an emission buffer memory, storing data packets, resulting from the division of the compressed frames issued from the intermediate buffer memory, and emitting, with a controlled bit rate, the data packets on a communication channel. The encoder includes a control module, which dynamically adjusts the maximum size of the capture buffer memory, permitting the maximum size of the capture buffer memory to be temporarily increased as long as the emission buffer memory is not empty.

Abstract: The invention concerns a decoder (2) comprising a first input for receiving a coded flow of second binary elements (Yd). It comprises a second input for receiving channel properties (Ic) designed to define probabilities of receiving second binary elements, upon transmitting first binary elements, a first module (12) defining a source model (8) adapted to define the probabilities for x-ray symbols associated with transitions between source states in a source state diagram, a so-called product model (7), adapted to define a correspondence between the x-ary symbols and the first binary elements produced in a product state diagram, a product state being a function of a source state, a processing module (6) adapted to calculate probabilities of decoding x-ary symbols, knowing bits of the coded flow of second binary elements from the channel properties (Ic) of the source model (8) and of the product model (7), and adapted to reconstitute the most probable flow of x-ary symbols from said computed probabilities.

Abstract: A multiple-reference motion-compensated predictive coding method is provided, which includes a multiple-reference motion estimation step, of the type making it possible to estimate the motion for each current frame included in a video sequence, from at least one initial list of reference frames for said current frame, each initial list LIi including Ni reference frames selected in a predetermined manner, with i>1 and Ni22 2. The multiple-reference motion estimation step includes the following steps for each current frame: for each initial list LIi, obtaining of a corresponding short list LRi by selecting ki reference frame(s) from among the Ni reference frames included in said initial list LIi, with 1<ki<Ni; and estimating motion based on the ki reference image(s) for each short list LRi. A flash frame detection step is performed based on the ki reference frame(s) selected for each short list LRi.

Abstract: Method and apparatus for detecting transitions in a video sequence, which include detecting an abrupt transition including, for each image It?2k included in said video sequence and with a processing time rank t=2k: calculating a first distance D(It?k), between an image It?k and a reference image for said image It?k, which precedes said image It?k in the video sequence; calculating a second distance D(It?2k), between an image It?2k and a reference image for said image It?2k, which precedes said image It?2k in the video sequence; calculating a third distance D(It?3k), between an image It?3k and a reference image for said image It?3k, which precedes said image It?3k in the video sequence; calculating a criterion C? indicating whether said second distance D(It?2k) is significantly greater than the largest of the first and third distances, D(It?k) and D(It?3k); deciding, according to said criterion C?, on the belonging of the image It?2k to an abrupt transition.

Abstract: The invention concerns a decoder (2) comprising a first input for receiving a coded flow of second binary elements (Yd). It comprises a second input for receiving channel properties (1c) designed to define probabilities of receiving second binary elements, upon transmitting first binary elements, a first module (12) defining a source model (8) adapted to define the probabilities for x-ray symbols associated with transitions between source states in a source state diagram, a so-called product model (7), adapted to define a correspondence between the x-ary symbols and the first binary elements produced in a product state diagram, a product state being a function of a source state, a processing module (6) adapted to calculate probabilities of decoding x-ary symbols, knowing bits of the coded flow of second binary elements from the channel properties (1c) of the source model (8) and of the product model (7), and adapted to reconstitute the most probable flow of x-ary symbols from said computed probabilities.