Abstract: In an embodiment, a method for converting an input video sequence, comprising digital images organized in frames and operating at a variable frame-rate, into an output video sequence, operating at a pre-set constant frame-rate, storing the input video sequence temporarily and controlling fetching of images of said temporarily stored input video sequence. The method further includes controlling fetching of images from the temporarily stored input video sequence by adjusting an emptying rate to form an intermediate video sequence; and carrying out an operation of motion-compensated interpolation on the intermediate video sequence to form the output video sequence operating at a pre-set constant frame-rate, the emptying rate being adjusted as a function of a number of images of the input video sequence with variable frame-rate temporarily stored. An application is in the reproduction of video sequences in mobile terminals, with the capacity of audio-video conversation, for example for videoconferences.

Abstract: In an embodiment, a method for converting an input video sequence, comprising digital images organized in frames and operating at a variable frame-rate, into an output video sequence, operating at a pre-set constant frame-rate, storing the input video sequence temporarily and controlling fetching of images of said temporarily stored input video sequence. The method further includes controlling fetching of images from the temporarily stored input video sequence by adjusting an emptying rate to form an intermediate video sequence; and carrying out an operation of motion-compensated interpolation on the intermediate video sequence to form the output video sequence operating at a pre-set constant frame-rate, the emptying rate being adjusted as a function of a number of images of the input video sequence with variable frame-rate temporarily stored. An application is in the reproduction of video sequences in mobile terminals, with the capacity of audio-video conversation, for example for videoconferences.

Abstract: In an embodiment of a method for converting an input video sequence, comprising digital images organized in frames and operating at a variable frame-rate, into an output video sequence, operating at a pre-set constant frame-rate, it is envisaged to store the input video sequence temporarily and to control fetching of images of said temporarily stored input video sequence. The method moreover envisages: controlling fetching of images from the temporarily stored input video sequence by adjusting an emptying rate to form an intermediate video sequence; and carrying out an operation of motion-compensated interpolation on the intermediate video sequence to form the output video sequence operating at a pre-set constant frame-rate, the emptying rate being adjusted as a function of a number of images of the input video sequence with variable frame-rate temporarily stored.

Abstract: The present invention relates to the demultiplexing of a digital data stream in a receiver so as to retain only those parts of the digital data stream required by the receiver. Such demultiplexing is particularly useful when applied to a receiver circuit in a television system having a digital set-top-box. A memory in the receiver stores packet identifiers of data packets required by the receiver, which are stored in the memory under the control of a first control circuit. A second control circuit extracts packet identifiers from incoming data packets in an input digital data stream. A third control circuit receives the extracted packet identifier and determines whether this matches one of the packet identifiers stored in the memory. A match signal is set by the third control circuit to the second control circuit responsive to a match. The second control circuit demultiplexes the input data packet responsive to the match signal.

Abstract: A spatial-type de-interlacing process to be applied to a digital image for obtaining a spatial reconstruction. Furthermore, to the digital image there are also applied one or more temporal-type motion compensation de-interlacing processes for obtaining one or more temporal reconstructions, and the spatial reconstruction and the one or more temporal reconstructions are sent to a decision module. The decision module applies a cost function to the spatial reconstruction and the temporal reconstructions and chooses from among the spatial reconstruction and the temporal reconstructions the one that minimizes the cost function. Preferential application is to display systems, in particular displays of a cathode-ray type, liquid-crystal type, and plasma type which use a mechanism of progressive scan.

Abstract: In an embodiment of a method for converting an input video sequence, comprising digital images organized in frames and operating at a variable frame-rate, into an output video sequence, operating at a pre-set constant frame-rate, it is envisaged to store the input video sequence temporarily and to control fetching of images of said temporarily stored input video sequence. The method moreover envisages: controlling fetching of images from the temporarily stored input video sequence by adjusting an emptying rate to form an intermediate video sequence; and carrying out an operation of motion-compensated interpolation on the intermediate video sequence to form the output video sequence operating at a pre-set constant frame-rate, the emptying rate being adjusted as a function of a number of images of the input video sequence with variable frame-rate temporarily stored.

Abstract: A system for generating motion vectors in a motion estimator is configured for co-operating with an engine for calculating estimation error for generating motion vectors, according to estimation errors and/or motion vectors previously generated. The system comprises a program memory that contains program data for a motion-estimation algorithm, and a motion-vector memory that contains data identifying said motion vectors previously calculated.

Abstract: A moving-image signal, such as typically a luminance signal organized in blocks of pixels is coded via a technique that envisages the steps of: comparing a block to be coded with a plurality of candidate prediction blocks; determining, for each candidate prediction block, a respective value of an index representing the difference between the block to be coded and each candidate prediction block; and choosing between the candidate prediction blocks, as a function of the respective value of the aforesaid index, a prediction block to be used for coding of the block to be coded. The signal is sampled pixel by pixel on the block to be coded and on the plurality of candidate prediction blocks, thus generating respective surfaces representing the pattern of the signal in the block to be coded and in the candidate prediction blocks. Chosen as an index is an index of the parallelism between the aforesaid respective surfaces.

Abstract: A process for realizing an estimate of global motion based on a sequence of subsequent video images, such as those received via an optical mouse (M) for the purposes of detecting its movement.

Abstract: A processing system, such as typically a CPU, is used for converting a digital signal organized in pixels, such as a video signal, between a first format and a second multiple-description format. The system comprises at least one input register and at least one output register, and is configured via instructions, that can be constituted at least in part by instructions of a SIMD type, so as to: order the pixels of the signal to be converted in a set of input registers; and take selectively the pixels from the aforesaid set of input registers and place them in an orderly way in at least one output register.

Abstract: Transcoder apparatus for transcoding an input video bit-stream having a first encoding profile (e.g., MPEG-2) into an output video bit-stream having a second encoding profile (e.g., H.264), the first encoding profile including motion estimation information, the apparatus including: a front-end for extracting the motion estimation information from the input video bit-stream, and a back-end for constructing the output bit-stream. The front-end and the back-end of the apparatus are interconnected (e.g., via a buffer) to pass the motion estimation information from the front-end to the back-end, thereby avoiding motion estimation in constructing the output bit-stream at the apparatus back-end.

Abstract: A coprocessor circuit for processing image data in digital form, having a motion vector controller block for generating, starting from the image data, motion vector values that include predictor data and macroblock data relating to a current macroblock of the image data to be estimated and being adapted to be stored at respective memory addresses. Also included is an address generator block for extracting respective addresses from the motion vector values, a predictor fetch block for retrieving predictor data based on respective addresses extracted by the address generator block, a current macroblock fetch and distengine block for retrieving macroblock data based on respective addresses extracted by the address generator block and for processing the macroblock data according to a given function, and a decision block for collecting the retrieved data as partial results and selecting the best result therefrom.

Abstract: A method controls operation of a network wherein at least one coded information stream is delivered to at least one user via at least one link exposed to variable operating conditions. The method includes the steps of: monitoring the operating conditions of the at least one link, and selectively transcoding the at least one coded information stream by selectively varying at least one transcoding parameter as a function of the operating conditions monitored. The monitoring operating conditions of the at least one link includes evaluating a set of cost functions related to an available bit rate and to complexity of said coded information stream and the selective variation of at least one transcoding parameter includes selecting among a plurality of transcoding levels associated to different values of quantization, resolution and frame rate.

Abstract: A method for encoding and decoding media signals, includes the operations of generating at a transmitting side multiple descriptions associated to data of the media signals through a downsampling operation performed on the data, and decoding at a receiving side the multiple descriptions for reconstructing the data by merging the multiple descriptions. The operation of generating multiple descriptions further includes the operations of obtaining a spectral representation of the data, including bands associated to different ranges, the bands being obtained by a suitable quantization operation and including at least one highly quantized band, that is subjected to a higher degree of quantization. A scrambling operation is performed on the spectral representation by moving the at least one highly quantized band to a different range, the scrambling operation being performed prior the downsampling operation. In decoding, a descrambling operation is performed before the merging operation on the multiple descriptions.

Abstract: A system controls operation of a network, such as a WLAN, where at least one information stream is delivered to at least one user via a link that is exposed to variable operating conditions. The system includes a controller module for monitoring the operating conditions of the link, and at least one transcoder for selectively transcoding the information stream by selectively varying one or more transcoding parameters as a function of the monitored operating conditions.

Abstract: The method is directed to encoding/decoding a video signal sequence by generating therefrom multiple description subsequences wherein the subsequences are produced by a plurality of parallel video encoding processes based on respective encoding parameters. The method includes the step of commonly controlling the encoding/decoding parameters for the plurality of video encoding/decoding processes.

Abstract: The method for encoding and/or decoding video signals, includes the operations of generating at a transmitter side a multiple descriptions vector associated to a pixel values vector of the video signals and decoding at a receiver side available descriptions vector for reconstructing the pixel values vector. The operation of generating a multiple descriptions vector includes the steps of obtaining the pixel values vector by selecting a group of pixels in a picture of the video signal and applying an encoding matrix to the pixel values vector. The decoding operation includes the step of applying a decoding matrix that is in an inverse relationship with the encoding matrix to the available descriptions vector to obtain the pixel values vector.

Abstract: A spatial-type de-interlacing process to be applied to a digital image for obtaining a spatial reconstruction. Furthermore, to the digital image there are also applied one or more temporal-type motion compensation de-interlacing processes for obtaining one or more temporal reconstructions, and the spatial reconstruction and the one or more temporal reconstructions are sent to a decision module. The decision module applies a cost function to the spatial reconstruction and the temporal reconstructions and chooses from among the spatial reconstruction and the temporal reconstructions the one that minimizes the cost function. Preferential application is to display systems, in particular displays of a cathode-ray type, liquid-crystal type, and plasma type which use a mechanism of progressive scan.

Abstract: A motion estimation process in video signals organized in successive frames divided into macroblocks that is carried out by the identification of motion vectors. In a first identification phase, starting from a current motion vector, a best motion vector predictor is identified, chosen from a set of candidates. The best predictor thus identified is then subjected to a second refining phase. The aforesaid set of candidates is identified by selecting vectors belonging to macroblocks close to the current vector within the current frame and the preceding frame. Preferably, the refining phase comprises the definition of a grid of n points centered on the central position to which the best motion vector points and the distance of the points of the grid from the center is defined as a function of the matching error typically consisting of an SAD function, defined in the first identification phase. Application to the IPB and APM operating modes of the H.263+ video standard is envisaged.

Abstract: A method of estimating the motion field of a digital picture sequence includes subdividing a current picture to examine in an integer number of macroblocks, for each macroblock of the current picture determining a search window centered on a macroblock of a preceding picture placed in the same position of the considered macroblock of the current picture, carrying out a motion estimation between the considered macroblock of the current picture and the macroblock most similar to it included in the window. At least a dimension of the search window is established as a function of the corresponding dimension of the search window used for the preceding picture, the estimated motion field of the preceding picture and certain threshold values.