Abstract: The invention relates to a device for pre-processing video images intended to be coded in the MPEG 2 format. The MPEG 2 standard provides that, mode which exploits the spatial redundancy of the images. The images thus coded then define a succession of groups of images, a group of images being referred to as a GOP. The pre-processing device according to the invention comprises an image memory and an analysis circuit. The image memory makes it possible to store the various images contained in the forecast GOP of rank ok and ax of the first few images contained in the GOP of rank ok+l, ax being an integer greater than or equal to 1. The analysis circuit is linked to the image memory and makes it possible to perform measurements on the images contained therein. The knowledge about the images of the GOP of rank and about the first images of the forecast GOP of rank k+1 which is ascertained following the above mentioned measurements is then used for coding the GOP of rank k.

Abstract: A variable length codeword decoder is responsive to a clock signal having multiple cycles and includes a source of sequential variable length codewords, each representing a run-length encoded codeword. A barrel shifter circuit is coupled to the codeword source and provides the next undecoded variable length codeword in lesser significant bits of its output terminal. A codeword decoding circuit is coupled to the output terminal of the barrel shifter and operates to decode two sequential variable length codewords, representing respective zero run run-length codewords, in a single clock cycle; or two sequential variable length codewords, a first representing a zero run run-length codeword and a second representing a one run run-length codeword, in a single clock cycle; and all other variable length codewords in a single clock cycle.

Abstract: An analog to digital converter transposes the input signal into two differential signals, which are applied to respective inputs of a differential comparator. The output of the differential comparator is linked to the input of the analog-digital converter by a circuitry loop for restoring a DC component of each of the differential signals at the mid-voltage of the conversion range of the analog-digital converter.

Abstract: The invention relates to a process for coding digital data of a video sequence for its transmission and a variable bit rate. It is characterized in that the bit rate regulation in respect of the image at the instant n is performed as a function of a bit rate prediction in respect of the transmission channel for the instant n+&tgr;, &tgr; being a constant time between the instant of storage of an image in the buffer of the coder and the instant of output of this image from the buffer of the decoder.

Abstract: A video processing device capable of minimizing clock cycles lost to overhead information includes an encoder for generating first and second groups of overhead bits. The first group includes a fixed number of overhead bits and the second group includes a variable number of overhead bits. A shift register receives pixel data from a data source, receives the second group of overhead bits from the encoder, and provides output of the pixel data and the second group of overhead bits. A multiplexer receives the pixel data and the second group of overhead bits from the shift register, receives the first group of overhead bits from the encoder, and provides output of the pixel data and the first and second groups of overhead bits which are then combined in an output register.

Abstract: A video decoder provides an interface enabling a User to create, manage and maintain favorite service lists for facilitating User navigation through a complex array of multimedia services. The on-screen display interface system generates an abbreviated menu list of favorite multimedia services available from both local and remote sources to enable navigation through user selected favorite services. A database associates individual services and corresponding menu items in the favorite services menu with their respective sources and supports service selection, tuning and acquisition. Additional abbreviated lists of favorite multimedia services, comprising sub-sets of parent service lists, are also hierarchically displayed in response to User command in order to facilitate and focus a search for a desired service.

Abstract: A cache enabling architecture in which an optical storage reading and/or writing device, a caching processor and a mass writing and reading device are each connected to a data bus. The optical storage reading and/or writing device exchanges information directly with the caching processor over the data bus. The caching uses the mass writing and reading device as cache memory.

Abstract: In an MPEG compatible image signal processor an MPEG data stream is decoded, decompressed and recompressed before blocks of image pixel values are stored in memory. The recompression system evaluates block data to determine the range and minimum pixel values for a given image block of pixels values. These values are encoded, and the encoded representations are stored in a parameter field with the quantized data block to facilitate data reconstruction. Encoding occurs by fitting the actual range and minimum values to a predetermined set of values. Each selected predetermined value is then encoded as a three-bit index in the parameter field. Storing the encoded values with the quantized data facilitates reconstruction with minimal error. Also, encoding the values preserves memory for the quantized data.

Abstract: A system and method reduces multipass signal degradation attributable to non-linear processing, namely quantization and dequantization. In one embodiment, a decoder decodes a predetermined unit of data utilizing a first quantization value. A quantization restrictor receives the first quantization value and generates a second quantization value having a restricted value wherein the second quantization value is equal to the first quantization value divided by a given integer. An encoder encodes the predetermined unit of data utilizing the second quantization value. A function unit can be provided for performing a predetermined pixel domain function on the predetermined unit of data between the decoding operation of the decoder and the encoding operation of the encoder. In this system, the decoder performs an inverse discrete cosine transform on the predetermined unit of data, and dequantizes the predetermined unit of data.

Abstract: A block based signal compression system, as for example for coding video signal, and employing quantization of codewords or transform coefficients includes circuitry for adaptively controlling the quantization. Adaptivity of quantization is made a function of several parameters. One parameter is coding cost or bandwidth, wherein coding cost is generated on a macroblock basis but averaged over a window of macroblocks centered on a macroblock currently to be quantized. Another parameter is block or macroblock motion attributes, wherein block motion attribut values are used to modify the quantizing function.

Abstract: A device for estimating motion between a current image and a previous image by block matching, the images being split into blocks. The device includes a processing circuit for each candidate motion vector and at least one memory. Each processing circuit calculates errors between a block of the current image and the block designated by a respective candidate motion vector in the previous image. The processing circuit successively receives pixels of the current image according to a line scan at a first input and corresponding pixels of the previous image identified by the associated candidate motion vector at a second input. The processing circuit calculates partial sums at the end of line of each block of the current image corresponding to accumulated errors for this block. The processing circuits further include an output for delivering the partial sums and a third input for receiving the partial sums.

Abstract: The present invention relates to a process and device for labeling a region in which the regions are defined by the juxtaposition of segments of a line, which are portions of a line. During a line scan of an image, the invention increments and allocates a label to each segment encountered on the current line when this segment is not connected to any segments of the preceding line. The invention allocates the same label to each segment encountered on the current line as that assigned to the segment of the preceding line when it is connected to the segment. The invention allocates the same label to each segment encountered on the current line as that assigned to the first of the segments of the preceding line. In this last case, the invention stores the relationship between the labels of the successive segments to one and the same segment of the current line.

Abstract: For compatible transmission of a television picture having an aspect ratio of 16:9 within a 4:3 system, transmission is effected in the letterbox format in accordance with the PALplus system specification. The receiver reconstructs the original picture with the aid of vertical filters and is able, furthermore, to suppress crosstalk interference from the luminance signals in the chrominance signals. To further improve the picture quality, the picture is displayed at a frame frequency of 100 Hz. For this purpose, the picture supplied at 50 Hz with line interlacing must be converted to a frame frequency of 100 Hz. Known concepts for PALplus decoding and 100 Hz conversion carry out these processes separately and in doing so require a great deal of memory space.

Abstract: A method for compatibly tuning a video signal receiver to an image processing device involves generating a prompting message for display to prompt a user to initiate a command response. First and second signals are generated. Each signal incorporates the prompting message but only one of the signals is compatibly tuned to the display. The first and second signals are alternately provided to the display and the prompting message is legibly displayed when the compatibly tuned signal is provided. The signal that is compatibly tuned to the display is selected in response to the command.

Abstract: Channel map information includes program map table information in packetized program information used in video processing and storage medium formats. In a digital video system for decoding an MPEG compatible datastream containing MPEG compatible program map table information, channel map information is identified and assembled. The channel map information identifies individual packetized datastreams that constitute a broadcast program. The channel map information associates a broadcast channel with packet identifiers used to identify individual packetized datastreams that constitute a program transmitted in the broadcast channel. The channel map information replicates information conveyed in the MPEG compatible program map table information.

Abstract: Noise reduction circuitry, in a video signal compression apparatus of the predictive DPCM compression type includes a simple nonlinear processing element within the DPCM loop to eliminate residues between predicted and real image signals, which are smaller than a predetermined value. Elimination of such residues dramatically reduces the amount of compressed data generated for signals including even modest amounts of noise.

Abstract: Program channels are allocated first and second identification numbers in packetized program information used in video processing and storage medium formats. Packetized program information is decoded to provide data content of a program. Channel map information in the packetized program information is identified. The channel map includes a first identification number for use in identifying a first broadcast sub-channel and the first identification number is associated with a first broadcast source. The channel map also includes a second identification number for use in identifying the first broadcast sub-channel from among a group of sub-channels associated with the first identification number. The identified information is assembled to form a channel map suitable for use in identifying a program transmitted on the first broadcast channel using the first and second identification numbers in conjunction.

Abstract: Packetized video program information used in video processing and storage medium formats includes program related text messages. A decoder decodes packetized video program information including program related text messages. The decoder determines a broadcast programming time segment associated with a desired program related text message and identifies program related text message data occurring in the determined broadcast programming time segment. The decoder acquires the identified program related text message data and formats the text message data for display.

Abstract: The computation-intensive task of motion estimation for video signals is performed by block search methods using apparatus of reduced complexity. Motion estimation is performed by analyzing only specific bits, e.g. one or two MSBs, of the picture element values. These bits are logic-linked by means of EXOR and/or EXNOR functions, and the individual results for different block positions of a current block within a search window are combined. The respective motion vector for the current block is determined by using a minimum or maximum comparison.

Abstract: The process is characterized in that the pilot signals (10) generated upstream of the device (11) whose non-linearity it is desired to measure pass through a known non-linear device (15) delivering intermodulation products of known characteristics and in that at least one of the known intermodulation products is harnessed in order to modulate, with the aid of synchronous detection circuits (17), at least one of the signals relating to the components of the intermodulation products of the device to be measured.The applications pertain to the analog transmission of television signals over optical fibers.