Abstract: Approaches for generating dynamic over-the-top (OTT) adjustable bit rate (ABR) representations of a video with a variable resolution and/or frame rate using on-the-fly (OTF) transcoding and assistance metadata. At an encoder located at a head-end, the encoder encodes a video stream at an initial bit rate and produces optimum representation (OpRep) metadata, which describes an optimum presentation for the video stream for each of a plurality of bit rates or the minimum bitrate below which a presentation becomes sub-optimal. The head-end transmits the encoded video stream and the OpRep metadata to a transcoder of a Content Delivery Network (CDN). The transcoder at the CDN uses the OpRep metadata to dynamically transcode the video stream in a preferred picture resolution and a preferred frame rate at a different bit rate than the initial bit rate using the OpRep metadata.

Abstract: A video server comprising an input port configured to receive from a user terminal requests to deliver video segments in a target representation. The server comprises an output port configured to deliver the requested video segments to the user terminal. The server comprises a data link configured to retrieve from storage capabilities, for each request from the user terminal, a video segment in at least one source representation in an Open GOP scheme. The server comprises an access to one or more video transcoding capabilities. The video server is configured to cause one or more video transcoding capabilities to transcode at least a part of the video segment in at least one source representation in an Open GOP scheme into the requested target representation in a Closed GOP scheme when the requested target representation is different from a representation previously provided to the user terminal.

Abstract: The present invention concerns a method for dynamically adapting the lossy encoding of an audio and/or video stream (112) transmitted by a first device (101) to a remote device (102), said method comprising the following steps: the remote device (102) receives and decodes said stream (112), called the incoming stream, and transmits an outgoing stream (111) having at least one indicator relating to a state of said remote device (102) that is modified by the execution of the decoding of the incoming stream (112); the first device (101) receives the outgoing stream (111), extracts said at least one indicator therefrom and adapts the encoding of the incoming stream (112) according to said at least one extracted indicator. The method can be applied notably to video conferences conducted on the basis of self-powered terminals for the purpose of maintaining the operating period of these terminals.

Abstract: Method of adaptive broadcasting of multimedia data streams Fi originating from a service provider (20), during a download between a reception terminal (40) and a server (30), as a function of an energy criterion, comprising the following steps: determining, for N representations Fi, at least one first energy index by calculating, for each of the representations Fi of a multimedia segment, a value of energy Ei(t) consumed to decode the representation Fi at the instant t, the maximum energy value Emax(t) associated with the most energy-consuming representation, and the values of the ratios corresponding E i ? ( t ) E Max ? ( t ) ?storing these values in a file associating with a representation Fi at least one ratio E i ? ( t ) E Max ? ( t ) , measuring the consumption of energy used by the terminal in the course of the playback of the representation Fi, and choosing another representation Fj or altering the quality of playback of the representation if the

Abstract: A video server comprising an input port configured to receive from a user terminal requests to deliver video segments in a target representation. The server comprises an output port configured to deliver the requested video segments to the user terminal. The server comprises a data link configured to retrieve from storage capabilities, for each request from the user terminal, a video segment in at least one source representation in an Open GOP scheme. The server comprises an access to one or more video transcoding capabilities. The video server is configured to cause one or more video transcoding capabilities to transcode at least a part of the video segment in at least one source representation in an Open GOP scheme into the requested target representation in a Closed GOP scheme when the requested target representation is different from a representation previously provided to the user terminal.

Abstract: Method of adaptive broadcasting of multimedia data streams Fi originating from a service provider (20), during a download between a reception terminal (40) and a server (30), as a function of an energy criterion, comprising the following steps: determining, for N representations Fi, at least one first energy index by calculating, for each of the representations Fi of a multimedia segment, a value of energy Ei(t) consumed to decode the representation Fi at the instant t, the maximum energy value Emax(t) associated with the most energy-consuming representation, and the values of the ratios corresponding E i ? ( t ) E Max ? ( t ) storing these values in a file associating with a representation Fi at least one ratio E i ? ( t ) E Max ? ( t ) , measuring the consumption of energy used by the terminal in the course of the playback of the representation Fi, and choosing another representation Fj or altering the quality of playback of the representation if the energy

Abstract: The present invention concerns a method for dynamically adapting the lossy encoding of an audio and/or video stream (112) transmitted by a first device (101) to a remote device (102), said method comprising the following steps: the remote device (102) receives and decodes said stream (112), called the incoming stream, and transmits an outgoing stream (111) having at least one indicator relating to a state of said remote device (102) that is modified by the execution of the decoding of the incoming stream (112); the first device (101) receives the outgoing stream (111), extracts said at least one indicator therefrom and adapts the encoding of the incoming stream (112) according to said at least one extracted indicator. The method can be applied notably to video conferences conducted on the basis of self-powered terminals for the purpose of maintaining the operating period of these terminals.

Abstract: The present invention relates to a method of dynamic quantization of a stream of images including blocks (210) of different types transposed into the transform domain, the method comprising a first step of quantization (201) of several of said blocks with initial quantization coefficients (211), the method comprising a step of determination (202), for several types of block respectively, of the residual encoding costs after said first quantization (201), and a second step of quantization (204) of the transposed blocks (210) of at least one type with quantization coefficients chosen (203) according to the distribution of said residual costs between several types of block. The invention applies to encoders comprising a step of quantization capable of applying different quantization coefficients according to the types of block of images to be encoded.

Abstract: The invention relates to a method for coding a sequence of images, comprising the following steps: determining, for the image data, the prediction image data from reference image data, calculating residual data from image data and prediction image data, quantizing the residual data with a quantization step, reconstructing the image data into reconstructed image data, filtering the reconstructed image data according to at least one filtering parameter with a view to their use as reference image data, coding the quantized residual data, selecting a function representing the variations of at least one filtering parameter according to a quantization step value of a set of at least two functions from a predetermined value representative of a filtering intensity, determining the value of at least one filtering parameter from the function selected and the quantization step.

Abstract: The invention relates to a method for coding a sequence of images divided into blocks, comprising the following steps for a current block:—selecting, for the current block, a coding mode in a set of coding modes that comprises at least two coding modes, and a transform in a set of transforms that comprises at least a first transform and a second transform; and—coding the current block according to the coding mode and the transform selected. The coding mode and the transform, themselves, are selected according to the following steps:—selecting the coding mode in the set of coding modes while using the first transform, and—selecting the transform in the set of transforms while using the coding mode selected.

Abstract: The method is characterized in that the step for selecting a coding mode from the inter modes and from the intra modes is broken down into two sequential steps, a step for preselecting the intra coding mode for preselecting an intra mode for the current macroblock from the intra coding modes, and a coding decision step, part of the effective coding of the current macroblock for selecting the mode of coding the current macroblock from the inter modes and the preselected intra mode and in that the preselection step for the current macroblock is carried out during the coding decision step for a preceding macroblock.

Abstract: The invention relates to a method for coding a sequence of images, comprising the following steps: determining, for the image data, the prediction image data from reference image data, calculating residual data from image data and prediction image data, quantizing the residual data with a quantization step, reconstructing the image data into reconstructed image data, filtering the reconstructed image data according to at least one filtering parameter with a view to their use as reference image data, coding the quantized residual data, selecting a function representing the variations of at least one filtering parameter according to a quantization step value of a set of at least two functions from a predetermined value representative of a filtering intensity, determining the value of at least one filtering parameter from the function selected and the quantization step.

Abstract: The invention relates to a device for double pass encoding of a video data stream comprising: a first type encoding means performing the first encoding pass, a second type encoding means performing the second encoding pass. According to the invention, the second type encoding means are different from the first type encoding means and the second type encoding means use encoding information originating from the first encoding pass. Application to MPEG-2 and H.264 encoding.

Abstract: Image sequences are advantageously recoded based on an evaluation of complexities before and after trans-coding of the images. Initially, information is extracted representing at least the complexity of recoding each image. A complexity ratio is calculated in accordance with the complexities of images recoded previously using the aforementioned mode to the complexities of the initial coding of said images. After smoothing the complexity ratio undergoes updating. Each image is recoded according to the mode by estimating the complexity of each image to be recoded as the product of the complexity of the initial coding of the image by the smoothed complexity ratio for the mode.

Abstract: The invention relates to a device for coding video frame sequences, comprising means (1) for measuring the spatial activity of the video frames to be coded, means (1) for measuring the temporal activity of the video frames to be coded, means (2) for coding the frames as a frame structure or as a field structure. According to the invention, the means (2) for coding the frames as a frame structure or as a field structure are able to choose the field or frame structure dynamically as a function of the measurements of spatial and temporal activity of the said frame.

Abstract: The invention relates to a device for double pass encoding of a video data stream comprising: a first type encoding means performing the first encoding pass, a second type encoding means performing the second encoding pass. According to the invention, the second type encoding means are different from the first type encoding means and the second type encoding means use encoding information originating from the first encoding pass. Application to MPEG-2 and H.264 encoding.

Abstract: The method is characterized in that the step for selecting a coding mode from the inter modes and from the intra modes is broken down into two sequential steps, a step for preselecting the intra coding mode for preselecting an intra mode for the current macroblock from the intra coding modes, and a coding decision step, part of the effective coding of the current macroblock for selecting the mode of coding the current macroblock from the inter modes and the preselected intra mode and in that the preselection step for the current macroblock is carried out during the coding decision step for a preceding macroblock.

Abstract: The present invention relates to a method and a device for monitoring the quality of video data having to undergo coding and decoding, making it possible to maintain predetermined constant quality of the video data after decoding. The method is such that information representing the complexity of video data to be coded is received from at least one coder. For each video-data item to be coded, a reference quantization value is calculated as a function of the complexity. For each video-data item to be coded, a reference throughput calculated as a function of the reference quantization value and of the value of the predetermined constant quality is calculated and transmitted to the coder, allowing the coder to code each video data item so as to obtain video data at the predetermined quality, after decoding.

Abstract: The process implements a global regulation at the level of a horizontal band of the image, band consisting of panels, an encoder being assigned to each panel, as a function of a preset bit rate for the band and on the basis of a single Video Buffering Verifier (VBV) taking into account the state of the buffer memories of the encoders of the band.

Abstract: The invention relates to a device for recoding images, using a given set throughout, from a video stream comprising image sequences initially coded according to at least one mode.