Abstract: Methods, medium, and machines which compress, enhance, encode, transmit, decompress and display digital video images in real time. Real time compression is achieved by sub-sampling each frame of a video signal, filtering the pixel values, and encoding. Real time transmission is achieved due to high levels of effective compression. Real time decompression is achieved by decoding and decompressing the encoded data to display high quality images. Receiver can alter various setting including but not limited to the format for the compression, image size, frame rate, brightness and contrast.

Abstract: Methods and apparatuses for blending two images using vector table look up operations. In one aspect of the invention, a method to blend two images includes: loading a vector of keys into a vector register; converting the vector of keys into a first vector of blending factors for the first image and a second vector of blending factors for the second image using a plurality of look up tables; and computing an image attribute for the blended image using the blending factors.

Abstract: A method and an apparatus for error resilient, digital image scrambling are disclosed. Error resilience scrambling is produced by shuffling transform coefficients between arrays of coefficients arranged along an axis substantially orthogonal to the axis along which packetization of the coefficients proceeds. Scrambling transform coefficients requires a reasonable level of processing resources and has minimal impact on the efficiency of the compression process. Shuffling can be performed in a number of ways to provide good access security and a variety of security. Scrambling the image data in a direction substantially orthogonal to the direction of packetization of the transform coefficients distributes any transmission error in the image reducing the effects of data error or loss on the displayed image.

Abstract: An optimal scanning method for coding/decoding an image signal is provided. In a method of coding an image signal through a discrete cosine transform, at least one is selected among a plurality of reference blocks. A scanning order in which to scan blocks to be coded of the reference blocks is generated and the blocks to be coded are scanned in the order of the generated scanning order. The at least one selected reference block is temporally or spatially adjacent to the block to be coded. When the blocks to be coded are scanned, probabilities that non-zero coefficients occur are obtained from the at least one selected reference block, and the scanning order is determined in descending order starting from the highest probability. Here, the scanning order is generated to be a zigzag scanning order if the probabilities are identical. The optimal scanning method increases signal compression efficiency.

Abstract: The invention is related to methods and apparatus that recover usable video data from partially corrupted data. Embodiments inspect corrupted data packets and identify the location or locations of an error, whether the corrupted data packet contains data expected to be error-free, and whether the error-free data should be used. Decoding of a packet in both the forward direction and the backward direction can be used to locate a position of an error. Intra-coded macroblocks can also be recovered. A decoder can elect to use or to drop an intra-coded macroblock recovered from a corrupted data packet according to further criteria that is applied to the recovered intra-coded macroblock. One embodiment inspects video bitstream data that has been encoded with an optional data partitioning feature enabled, and retrieves specified data in areas of a corrupted packet that are expected to be free from error.

Abstract: An exemplary embodiment of the invention relates to a method of using pattern vectors for image coding and decoding. The method comprises converting a block of image data into a set of transform coefficients, quantizing the transform coefficients such that a number of the coefficients become zero, constructing a single entity or bit vector indicating which coefficients are non-zero, coding the single entity or bit vector as an integer using an adaptive, semi-adaptive or non-adaptive arithmetic coder, coding the values of the coefficients in any fixed order, using an adaptive, semi-adaptive or non-adaptive arithmetic coder, or some other coder, and coding all coefficients except the zero coefficients. The system and method of decoding data relate to the corresponding hardware and process steps performed by the decoder when decoding a bitstream coded as described herein.

Abstract: A robust fine granularity scalability video encoding includes a base layer encoder and an enhancement layer encoder in which motion compensated difference images are generated by comparing an original image to predicted images at base layer and enhancement layer with motion compensation. Based on leaky and partial predictions, a high quality reference image is constructed at the enhancement layer to improve temporal prediction. In the construction of the high quality reference image, one parameter ? controls the number of bitplanes of the enhancement layer difference coefficients used and another parameter ? controls the amount of predictive leak. A spatial scalability module allows the processed pictures at the base layer and the enhancement layer to have identical or different spatial resolutions.

Abstract: Encoded data using reversible variable length code words is input to a forward decoder (123) to be decoded in the forward direction. When an error is detected in the encoded data in the forward decode processing, backward decode processing is started by a backward decoder (126). A decode value determination unit (125) determines a decode value by using the forward and backward decode results and the error detection positions in the encoded data in units of bits and syntax which are respectively detected in the forward decoding and the backward decoding.

Abstract: An interactive system for obtaining data for diagnostic purposes from a server having access to stores of said data wherein the server supplies the data and software to a data requesting user that enables the user to receive the data progressively so as to decide during the receipt of the data what portions of the data are to be received thereby decreasing the time required to receive the data and that enables the user to load the software to process the supplied data.

Abstract: The invention concerns a digital data compression encoder, characterized in that it comprises: an input for a first data flow (SH), and a second data flow (SL), an encoding module, matching symbols of the first data flow, and code words, wherein, for certain symbols, there exist several words, called redundant, corresponding to the same symbol, and a processing module for encoding the symbols of the first data flow based on the correspondence, by selecting among the redundant words, on the basis of at least part of the second data flow.

Abstract: A signal recording apparatus includes a quantizer for quantizing a signal employing a quantization step. The apparatus further includes a quantization information creator for creating plural pieces of quantization information to specify the quantization step, an encoder for generating an encoded signal from the quantized signal, and a recorder for recording a compressed signal having data containing the plural pieces of quantization information and the encoded signal.

Abstract: A method of representing encoding or non-encoding by extending a video information field of a block when coding video information, is provided. The method of representing encoding or non-encoding by extending an information field for representing encoding or non-encoding is applied to an error allowable mode. Also, the amount of bits depending on the characteristics of video information to be encoded can be reduced. In this method, an image is encoded by extending a code (COD) field which is used in H.263 and MPEG-4 to indicate the cases where neither a motion vector (MV) nor a discrete cosine transform (DCT) value are encoded, where both the MV and the DCT value are encoded, and where only the MV is encoded. Therefore, in a channel with errors, the extended OCD field can be used in the error allowable mode. Also, video information can be encoded using a smaller amount of bits where the motion of an image is constant, than in the conventional art.

Abstract: There are provided a variable-length code decoding apparatus and method which can perform high-speed decoding processing without decreasing an image size and frame rate. A variable-length code decoding apparatus of this invention decodes a variable-length code containing a prefix and a suffix. This apparatus includes a prefix decoding unit which decodes the prefix of an input variable-length code and outputs a symbol and prefix length corresponding to the prefix, a suffix shifter unit which supplies the suffix on the basis of the prefix length output from the prefix decoding unit, and a symbol decoding unit which decodes a symbol corresponding to a variable-length code on the basis of the symbol corresponding to the prefix which is output from the prefix decoding unit, the suffix supplied by the suffix shifter unit, and a suffix length acquired in advance.

Abstract: System and method for balancing video encoding tasks between multiple processors. The method may include receiving a real time video stream, performing picture level and upper processing on a main processor, executing a macroblock loop in parallel on a main processor and a co-processor, wherein executing includes processing a first group of video encoding tasks on the main processor and processing a second group of video encoding tasks on the co-processor, and outputting an encoded version of the real time broadcast. The method may be implemented on a system that includes a main processor, a co-processor, and an interface to receive the real time video stream, each coupled to one or more buses. The encoding may be performed according to the well known Moving Pictures Experts Group (MPEG) standards.

Abstract: The invention relates to a decoding apparatus and same method for decoding a video bit stream. The apparatus decodes an encoded video bit stream to produce pixel data of a first and second macroblocks. The video bit stream comprises at least one video packet, a first, second, third logic units. The first logic unit comprising parameters a1 and b1. The second logic unit comprises parameters a2 and b2. The third logic unit comprises parameters a3 and b3. The parameters a1 and a2 are used for reconstructing a first macroblock. The parameters b1 and b2 are used for reconstructing a second macroblock. The video decoding apparatus comprises a searching module and a decoding module. The searching module locates a first address indicating location of the first logic unit, a second address indicating location of the second logic unit, and a third address indicating location of the third logic unit.

Abstract: A decoder for decoding a plurality of digital video data is described. In an embodiment, the decoder comprises a DV video decoder for decoding digital video data which is formatted according to the DV standard. The DV video decoder has a Very-Long Instruction Word (VLIW) processor and a variable length decoding unit. The VLIW processor includes a preparser unit for recovering a decoding order of the digital video data so that the variable length decoding unit can process the digital video data. The variable length decoding unit decodes a variable length coding format of the digital video data which has been preparsed by the VLIW processor. Furthermore, the VLIW processor includes a decompression unit for decompressing the digital video data which has been decoded by the variable length decoding unit. In an embodiment, the VLIW processor and the variable length decoding unit are formed on the same semiconductor device.

Abstract: A drift reduction method and apparatus. Drift reduction is effected in an MPEG video transcoder by decoding dropped out pixels to form a drift reference frame. The quantization indices in the current macro-block are changed accordingly in a drift reduction process. The compensated quantized frame is then variable length coded to an MPEG bitstream.

Abstract: A discrete cosine transform (DCT) level enhancement to Motion Picture Experts Group (MPEG) video encoding is described that results in a more concise bitstream than MPEG encoding without the enhancement. One degree of freedom provided by the MPEG encoding specifications is whether a frame- or field-based DCT operation will be used. In the field-based DCT operations, luminance sub-blocks are built from even or odd rows of the original image, which correspond to the top and bottom fields in field-based video. This allows the encoder to take advantage of the higher correlation between rows for the same field, especially in field-based video with a high level of motion. In one embodiment, both field- and frame-based DCT operations are performed and the results are quantized. On a macroblock-by-macroblock basis, the option that results in the fewest non-zero coefficients is selected and those coefficients are used for run-time encoding.

Abstract: A method and system for decoding symbols of variable length in a digital video bit stream in real time, using Very Long Instruction Word (VLIW) architecture. In one embodiment, several bit sections are first read from a bit stream. While the first bit section will correspond to a valid symbol in the bit-stream, the rest of the bit sections may or may not, depending on the length of the first section. A table of variable length codes is then indexed to obtain a look-up result for each of the read-in bit sections, which done in parallel for all sections. Next, a determination is made as to whether each of the look-up results is valid. A valid look-up result provides the length of the symbol. The valid look-up values are then accepted. In another embodiment the bit stream is thereafter advanced by the sum of all accepted look-up results.

Abstract: Encoded data using reversible variable length code words is input to a forward decoder (123) to be decoded in the forward direction. When an error is detected in the encoded data in the forward decode processing, backward decode processing is started by a backward decoder (126). A decode value determination unit (125) determines a decode value by using the forward and backward decode results and the error detection positions in the encoded data in units of bits and syntax which are respectively detected in the forward decoding and the backward decoding.

Abstract: The present invention selectively applies one of VLC tables stored in a memory for encoding a coded block pattern of a macroblock according to the number of blocks having an object within the macroblock, the number of blocks obtained using shape information, thereby reducing the amount of data transmitted and increasing coding efficiency. The present invention also selectively applies one of VLD tables stored in a memory for decoding a coded block pattern of a macroblock according to the number of blocks having an object within the macroblock, the number of blocks obtained using shape information.

Abstract: An apparatus and method thereof to encode a moving image include a discrete cosine transform (DCT) unit performing a DCT process on input video data, a quantizer, and a motion estimation (ME) unit calculating a motion vector and a SAD per macro block. A DCT computational complexity calculator calculates a computational complexity of the ME unit, estimates a difference between the ME computational complexity and a target ME computational complexity, and updates a target DCT computational complexity based on the estimated difference. A DCT skipping unit sets a threshold value to determine whether to skip performing the DCT process on the input video data, based on the target DCT computational complexity updated by the DCT computational complexity calculator, compares the SAD per macro block, and the quantization parameter with the threshold value, and determines whether to allow the DCT unit to perform the DCT process on the input video data.

Abstract: A technique is described for decoding an MPEG-4 run-length-limited (RLL) code word using a hardware designed to decode MPEG-2 RLL code words.

Abstract: Transform coefficients of sample blocks of a macroblock of a video picture are encoded by adaptively encoding in combination, the number of non-zero coefficients before the trailing one coefficients and the number of trailing one coefficients. The transform coefficients may be further encoded by adaptively encoding one or more of the signs of the trailing one coefficients, the level measures of the non-zero coefficients, the total number of zero coefficients interposed in the non-zero coefficients, and the respective run lengths of the zero coefficients. Adaptive encoding of the number and trailing one coefficients may be performed in view of one or more neighboring sample blocks, whereas adaptive encoding of level measures may be performed in view of quantization parameters of a macroblock and previously encoded level measures. Decoding may be performed in an inverse manner.

Abstract: A method and apparatus for variable accuracy inter-picture timing specification for digital video encoding is disclosed. Specifically, the present invention discloses a system that allows the relative timing of nearby video pictures to be encoded in a very efficient manner. In one embodiment, the display time difference between a current video picture and a nearby video picture is determined. The display time difference is then encoded into a digital representation of the video picture. In a preferred embodiment, the nearby video picture is the most recently transmitted stored picture. For coding efficiency, the display time difference may be encoded using a variable length coding system or arithmetic coding. In an alternate embodiment, the display time difference is encoded as a power of two to reduce the number of bits transmitted.

Abstract: A variable bit rate (VBR) representation of an image sequence is segmented based on a plurality of time intervals. For each of at least two of the time intervals, the method comprises: determining which of the packets, denoted by Pp, in the VBR representation within the presently-considered time interval has a number of blocks of information per unit time greater than a baseline value; determining which of the packets, denoted by Pn, in the VBR representation within the presently-considered time interval has a number of blocks of information per unit time less than the baseline value; and creating a second representation of the image sequence in which some blocks of information Bp are removed from at least one Pp packet and interlaced with blocks of information in at least one Pn packet to produce reformatted packets.

Abstract: A robust fine granularity scalability video encoding includes a base layer encoder and an enhancement layer encoder in which motion compensated difference images are generated by comparing an original image to predicted images at base layer and enhancement layer with motion compensation. Based on leaky and partial predictions, a high quality reference image is constructed at the enhancement layer to improve temporal prediction. In the construction of the high quality reference image, one parameter ? controls the number of bitplanes of the enhancement layer difference coefficients used and another parameter ? controls the amount of predictive leak. A spatial scalability module allows the processed pictures at the base layer and the enhancement layer to have identical or different spatial resolutions.

Abstract: Video encoding methods and video encoders that provide improved performance while reducing power consumption. In one aspect, a video encoding method comprises the steps of outputting a parameter for a slice of a current frame, wherein the slice comprises a plurality of macroblocks, processing the slice by consecutively encoding and decoding each macroblock of the slice in response to the parameter, and outputting an interrupt signal for the slice The parameter preferably comprises an address of the first macroblock of the slice, an address of a search area in a previous frame, the search area corresponding to a current macroblock in a current frame, and a number of macroblocks comprising the slice.

Abstract: An apparatus and method for performing bitplane coding with reordering, that may be used in a Fine Granularity Scalability (FGS) system. The apparatus and method reorder coefficients each time after a bitplane is coded. By reordering, the apparatus and method separate the coefficients into two groups. When coding a bitplane, bits in the first group are copied into the bitstream, while the bits in the second group are subject to common run-length, VLC, or arithmetic coding. The apparatus and method may also be used with or in a conventional SNR, temporal and/or spatially scalable architectures, for example, as utilized within an MPEG-4 framework.

Abstract: Edges are detected in block coded video by a threshold comparison upon the lengths of variable-length codes used for encoding the differential DC coefficients of the pixel blocks. A thinning filter compares the code lengths of the differential DC coefficients of adjacent blocks in order to retain the edge indications of more significant edges and to exclude the edge indications of less significant edges. The edge indications can be split into substantially independent channels for luminance or chrominance, for edges having positive or negative horizontal gradient components, and for edges having positive or negative vertical gradient components. The edge indications for successive frames in an MPEG sequence are compared to each other in various ways in order to detect scene changes.

Abstract: A method comprises determining a plurality of time intervals Tp and Tn within a variable bit rate (VBR) representation of an image sequence. The time intervals Tp are those in which a number of blocks of information per unit time is greater than a baseline value. The time intervals Tn are those in which a number of blocks of information per unit time is less than the baseline value. A second representation of the image sequence is created in which some blocks of information Bp are removed from the time intervals Tp and interlaced with blocks of information Bn in the time intervals Tn to reduce a variation in a number of blocks of information per unit time between the time intervals Tp and Tn.

Abstract: A method comprises determining a plurality of time intervals Tp and Tn within a variable bit rate (VBR) representation of an image sequence. The time intervals Tp are those in which a number of blocks of information per unit time is greater than a baseline value. The time intervals Tn are those in which a number of blocks of information per unit time is less than the baseline value. A second representation of the image sequence is created in which some blocks of information Bp are removed from the time intervals Tp and interlaced with blocks of information Bn in the time intervals Tn to reduce a variation in a number of blocks of information per unit time between the time intervals Tp and Tn.

Abstract: Methods and apparatuses for blending two images using vector table look up operations. In one aspect of the invention, a method to blend two images includes: loading a vector of keys into a vector register; converting the vector of keys into a first vector of blending factors for the first image and a second vector of blending factors for the second image using a plurality of look up tables; and computing an image attribute for the blended image using the blending factors.

Abstract: The present invention relates to an apparatus and a method for vector descriptor representation and multimedia data retrieval, which can quantize a plurality of feature values described by a vector descriptor respectively, represent the quantized feature values in the form of bit or orthogonally transform the quantized bector feature values, and rearrange the feature values represented in the form of bit from the highest bit to the lowest bit or rearrange the transformed coefficient from low frequency to high frequency to represent the vector descriptor hierarchically.

Abstract: Methods, medium, and machines which compress, encode, enhance, transmit, decompress and display digital video images in real time. Real time compression is achieved by sub-sampling each frame of a video signal, encoding and filtering the pixel values to codes, and run-length encoding the codes. Real time transmission is achieved due to high levels of effective compression. Real time decompression is achieved by decoding and decompressing the encoded data to display high quality images. High levels of effective compression also reduce the storage space requirement for recorded video.

Abstract: A communication system for performing transmission and reception of a signal over a communication channel assesses a state of the communication channel and produces channel state information accordingly. A block length selector selects block lengths that are dependent on the channel state information and that are selected from a group of block lengths having an integral multiple relationship to produce a schedule of block lengths. Encoding and decoding is performed based on the schedule of block lengths.

Abstract: A variable length coding method is provided. The method comprises comparing corresponding portions of a present picture and a previous picture received by a video encoder; and performing coding by fixing a COD (coded macroblock indication) flag of the present picture at a certain value, if said corresponding portions are similar to each other.

Abstract: The present embodiments address the need for an apparatus and method that provides additional orthogonal codes without trading off RF capacity. When a system is operating near its RF capacity and running out of available orthogonal codes, one or more channels are allocated using a new radio configuration (510) that utilizes longer orthogonal codes. This new radio configuration increases the number of available orthogonal codes without sacrificing RF capacity. Instead, it reduces the peak data rate such a channel can provide.

Abstract: A method comprises determining a plurality of time intervals Tp and Tn within a variable bit rate (VBR) representation of an image sequence. The time intervals Tp are those in which a number of blocks of information per unit time is greater than a baseline value. The time intervals Tn are those in which a number of blocks of information per unit time is less than the baseline value. A second representation of the image sequence is created in which some blocks of information Bp are removed from the time intervals Tp and interlaced with blocks of information Bn in the time intervals Tn to reduce a variation in a number of blocks of information per unit time between the time intervals Tp and Tn.

Abstract: An input digital signal of a first format (DV video signal) is restored to a variable-length code by having its framing cancelled by a de-framing section 11, then decoded by a variable-length decoding (VLD) section 12, inversely quantized by an inverse quantizing (IQ) section 13, and inversely weighted by an inverse weighting (IW) section 14. Then required resolution conversion in the orthogonal transform domain (frequency domain) is carried out on the inversely weighted video signal by a resolution converting section 16. After that, the video signal having the resolution converted is weighted by a weighting (W) section 18, then quantized by a quantizing (Q) section 19, coded by a variable-length coding by a variable-length coding (VLC) section 20, and outputted as a digital signal of a second format (MPEG video signal).

Abstract: Means of communicating between modules in a decoding system. A variable-length decoding accelerator communicates with a core decoder processor via a co-processor interface. In one embodiment, other decoding accelerators, in addition to the variable-length decoder, are adapted to provide status data indicative of their status to a co-processor status register. In another embodiment, a decoding accelerator is controlled by providing commands to the accelerator via posted write operations and polling the accelerator to determine whether the command has been performed. In still another embodiment, a first hardware accelerator communicates with a core decoder processor via a co-processor interface and other decoding accelerators, in addition to the first hardware accelerator, are adapted to provide status data indicative of their status to a co-processor status register.

Abstract: A picture decoding device of the present invention comprises a CPU, receiving as input encoded moving picture information, for subtracting ‘1’ from a slice start code inside slice information extracted from this information, a variable length code decoding circuit provided with a horizontal position generating circuit for subtracting ‘1’ from a macro block address (MBA) when output information formed from macro block position information (VP, HP), motion vectors, picture information etc. is output, using information output from the CPU, and a motion compensation circuit for carrying out decoding processing for the moving picture information, with origin coordinates set to (0,0), using a slice start code and macro block address after subtraction.

Abstract: An apparatus for partitioning moving picture data comprises a first quantizing unit for first-quantizing a received video signal and outputting a first-quantized signal; and a second quantizing unit for second-quantizing the first-quantized signal and partitioning the first-quantized signal into a preceding part and a succeeding part.

Abstract: The present invention selectively applies one of VLC tables stored in a memory for encoding a coded block pattern of a macroblock according to the number of blocks having an object within the macroblock, the number of blocks obtained using shape information, thereby reducing the amount of data transmitted and increasing coding efficiency. The present invention also selectively applies one of VLD tables stored in a memory for decoding a coded block pattern of a macroblock according to the number of blocks having an object within the macroblock, the number of blocks obtained using shape information.

Abstract: A variable length decoder (VLD) for decoding MPEG-1 and -2 syntax compliant video bit streams. The VLD includes a micro-sequencer and VLD command decode/execution unit for controlling the MPEG decoding process using a novel instruction set. The instruction set includes a set of commands for decoding the video data and a set of flow control instructions. A rotator/barrel shifter is provided for making a predetermined number of encoded bits from the video bit stream available to the VLD and a variable length table decoder for variable length decoding using the MPEG standard variable length code (VLC) tables. The variable length table decoder shares a prefix pattern matching scheme across all of the VLC tables and organizes the variable length codes into a series of subtables. Each subtable corresponds to one of the unique prefix patterns. Variable length codes are decoded by identifying a leading pattern in the video data bit stream and, in parallel, accessing the subtable corresponding to that leading pattern.

Abstract: A method achieves high performance MPEG-2 video variable length decoding as to improve MPEG-2 video decoding process on the whole. The method includes parsing bits, Huffman code decoding for macroblock address increment, decoding motion code, and decoding macroblocks including intra and non-intra macroblocks. This is suitable to any application that are compliant with MPEG-2 MP@ML or MP@ HL video standard. For example, in PC-DTV receiver application, with properly configured PC, one can receive DTV program in real time.

Abstract: A system and method for recording compressed data onto a storage medium so that it can be presented later in either lossy or lossless quality. The method receives a plurality of primary bit streams and supplemental bit streams representing data to be recorded onto the storage medium. Each primary bit stream is recorded onto the storage medium as it is received. As each of the supplemental bit streams are received, they are stored in a temporary memory location. After the primary bit streams have been recorded onto the storage medium, the supplemental bit streams are retrieved from the temporary memory location and recorded onto the storage medium. The recording process is completed when all the primary bit stream data and the supplemental bit stream data have been written onto the storage medium. To present the data, a user is given the option of viewing the data in either lossy quality or lossless quality.

Abstract: The object-oriented coder discriminates resource allocation between objects and non-objects for video messaging applications over wireless networks. The object-oriented coder executes a rate control algorithm, an unequal error protection algorithm, and an error concealment algorithm. In the rate control algorithm, an iterative feedback rate control scheme is used in which quantization values of object and non-object data are held constant. In the unequal error protection algorithm, the bit stream is partitioned by object macroblocks and non-object macroblocks. In the error concealment algorithm, five bits of QUANT values of each GOB are used for representing location and motion vectors of the object in the next frame, since the quantization value is constant. The five bits are not used for quantization value. The five bits are used for error concealment to avoid bit rate overhead. The object-oriented coder increases encoding delay, but this increase is acceptable in messaging.

Abstract: An MPEG decoder in a high definition television receiver decodes and decompresses MPEG coded data to produce decompressed image pixel blocks, and includes a motion compensation network coupled to a frame memory to produce finally decoded pixel data for display. The decompressed MPEG data is recompressed by plural parallel recompressors prior to storage in frame memory. Each recompressor receives a datastream of interleaved pixel data, and predicts and compresses interleaved pixel values during each clock cycle, respectively. One of the recompressors is de-energized in a reduced data processing mode when pixel data is subsampled prior to recompression. Subsampled data is re-ordered prior to recompression. Multiple parallel decompressors coupled to the frame memory provide pixel data to the motion processing network. A control unit insures an uninterrupted interleaved data flow to the decompressors by repeating last valid data when source data is interrupted.

Abstract: A method of video data compression is provided which is comparatively efficient in compressing data, and at the same time enables transmission of compressed data with sufficient robustness to withstand losses in the transmission channel. A frame of data is divided into coded macroblocks and skipped macroblocks which are grouped into respective slices in a sequence of slices. Respective slices are allowed to contain arbitrary numbers of consecutive macroblocks, and can begin and end at arbitrary positions within the frame. A run-length codeword, comprising a small number of bits, is inserted at the end of a slice to indicate the total number of skipped macroblocks between the final coded macroblock and the end of the slice. To further enhance error resilience an additional codeword, which also indicates the total number of skipped macroblocks, may be inserted at the beginning of the next-following slice.