Patent application number | Description | Published |
20080317134 | Video Coding - A low-complexity method for prevention of H.264 start code emulation by bit-handling routines with additional functionality. The low-complexity is achieved by employing a start code pre-determination scheme, which saves bitstream handling complexity by about 50% and 30% on the encoder and decoder sides, respectively. The start code emulation prevention has been embedded into the low-level bitstream handling routines. By doing so it avoids the use of the second bitstream buffer, maintains the decoder ability of using a circular bitstream buffer, and satisfies the BURST-aligned SDRAM access requirement. | 12-25-2008 |
20100098166 | VIDEO CODING WITH COMPRESSED REFERENCE FRAMES - A method and apparatus for video coding for reducing memory size and external memory access bandwidth in video coding, wherein the method compresses a reference frame prior to storing the reference frame to memory. | 04-22-2010 |
20100309976 | METHOD AND APPARATUS FOR ENHANCING REFERENCE FRAME SELECTION - A method and apparatus for selecting a reference frame for producing an encoded image. The method includes retrieving a histogram for a current frame, determining the difference between the histogram and a previous histogram, and calculating adaptive threshold utilizing the determined difference and encoding the frame as intra frame if it is an intra frame, and selecting a reference frame and encoding the frame as non-intra frame if the frame is a non-intra frame. | 12-09-2010 |
20110080947 | Line-Based Compression for Digital Image Data - A method of compressing digital image data is provided that includes selecting an entropy code for encoding a line of pixels in the digital image data, wherein the entropy code is selected from a plurality of variable length entropy codes, using spatial prediction to compute a pixel predictor and a pixel residual for a pixel in the line of pixels, and selectively encoding the pixel residual using one of the entropy code or run mode encoding. | 04-07-2011 |
20110080956 | Reducing Memory Bandwidth for Processing Digital Image Data - A method for processing digital image data is provided that includes compressing a block of the digital image data to generate a compressed block, storing the compressed block in an external memory when a number of bits in the compressed block does not exceed a first compression threshold, and storing the block in the external memory when the number of bits in the compressed block exceeds the first compression threshold. | 04-07-2011 |
20110142135 | Adaptive Use of Quarter-Pel Motion Compensation - A method of encoding a digital video sequence is provided that includes disabling quarter-pel motion compensation for a first sequence of blocks in the digital video sequence, computing an average half-pel cost for the first sequence of blocks, computing an average quarter-pel cost for the first sequence of blocks, and enabling quarter-pel motion compensation for a second sequence of blocks in the digital video sequence based on a comparison of the average half-pel cost and the average quarter-pel cost. | 06-16-2011 |
20110170594 | Method and System for Intracoding in Video Encoding - A method of intra-coding blocks of pixels in a digital video sequence is provided that includes selecting a block transform of a plurality of block transforms according to a spatial prediction mode used in generating a block of pixel residual values from a block of pixels, wherein the block transform is based on a single directional transform matrix predetermined for the spatial prediction mode and is a same size as the block of pixel values, applying the block transform to the block of pixel residual values to generate transform coefficients of the residual pixel values, and entropy coding the generated transform coefficients. | 07-14-2011 |
20110206289 | Guaranteed-Rate Tiled Image Data Compression - A method of compressing digital image data is provided that includes, for each image data block in a plurality of image data blocks in the digital image data, transforming image data in the image data block to convert the image data to a low-frequency coefficient and a plurality of high-frequency coefficients, computing a predicted low-frequency coefficient for the image data block based on at least one neighboring image data block in the plurality of image data blocks, computing a residual low-frequency coefficient based on the predicted low-frequency coefficient and the low-frequency coefficient, quantizing the plurality of high-frequency coefficients, and entropy coding the residual low-frequency coefficient and the quantized high-frequency coefficients. | 08-25-2011 |
20110216834 | Fixed Length Coding Based Image Data Compression - A method of compressing an image data block is provided that includes computing a pixel residual for each pixel in the image data block except a non-residual pixel, computing a compression level for the image data block based on a minimum pixel residual value and a maximum pixel residual value of the pixel residuals, encoding a compression flag for the image data block, wherein the compression flag includes an indicator identifying the compression level and a first portion of bits from the non-residual pixel, and generating a compressed block comprising a second portion of bits from the non-residual pixel and the pixel residuals encoded using fixed length coding based on the compression level. | 09-08-2011 |
20110274162 | Coding Unit Quantization Parameters in Video Coding - A method is provided that includes receiving a coded largest coding unit in a video decoder, wherein the coded largest coding unit includes a coded coding unit structure and a plurality of coded quantization parameters, and decoding the coded largest coding unit based on the coded coding unit structure and the plurality of coded quantization parameters. | 11-10-2011 |
20120007992 | Method and Apparatus for Sub-Picture Based Raster Scanning Coding Order - A method and apparatus for sub-picture based raster scanning coding order. The method includes dividing an image into even sub-pictures, and encoding parallel sub-pictures on multi-cores in raster scanning order within sub-pictures, wherein from core to core, coding of the sub-picture is independent around sub-picture boundaries, and wherein within a core, coding of a sub-picture is at least one of dependent or independent around sub-picture boundaries. | 01-12-2012 |
20120140815 | Quantization Matrix Compression in Video Coding - A method of quantization matrix compression in a video encoder is provided that includes preprocessing a quantization matrix by performing at least one selected from down-sampling the quantization matrix and imposing 135 degree symmetry on the quantization matrix, performing zigzag scanning on the pre-processed quantization matrix to generate a one dimensional (1D) sequence, predicting the 1D sequence to generate a residual 1D sequence, and coding the residual 1D sequence using kth order exp-Golomb coding to generate a compressed quantization matrix, wherein k≧0. | 06-07-2012 |
20120177104 | Reduced Complexity Adaptive Loop Filter (ALF) for Video Coding - Methods and apparatus for adaptive loop filtering in video coding are provided. The adaptive loop filtering may be largest coding unit (LCU) based, may use adaptive loop filter types in which the vertical size of a filter type is less than the horizontal size, may use a predefined set of filter types in which the vertical size of the largest filter type in the set is less than the horizontal size of the largest filter type in the set, may use a single adaptive loop filter type, and/or may use a filter type that is a cross with a center shape of a size dependent on an aspect ratio of the cross. | 07-12-2012 |
20120177122 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR DETERMINING A MOTION VECTOR - A prediction unit is identified within a picture of a video sequence. The prediction unit is bordered by neighboring prediction units within the picture. The neighboring prediction units include first and second neighboring prediction units that are separated from one another by at least a third neighboring prediction unit. A subset of the neighboring prediction units is scanned to identify an MVP candidate. The subset includes at least the first and second neighboring prediction units and excludes at least the third neighboring prediction unit. An encoder calculates a difference between a motion vector of the MVP candidate and a motion vector of the prediction unit, and encodes the difference and an index to identify the MVP candidate. A decoder decodes the difference, and calculates the motion vector of the prediction unit by adding the difference to the motion vector of the MVP candidate. | 07-12-2012 |
20120177123 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR COMPUTING A MOTION VECTOR - A prediction unit is identified within a picture of a video sequence. The prediction unit is bordered by neighboring prediction units within the picture. A match for the prediction unit is located within a first reference picture. At least a subset of the neighboring prediction units is scanned to identify a motion vector predictor (“MVP”) candidate. The MVP candidate of a first type is identified if available, wherein a match for the MVP candidate of the first type is located within the first reference picture. In response to the MVP candidate of the first type being unavailable, the MVP candidate of a second type is identified, wherein a match for the MVP candidate of the second type is located within a second reference picture. An encoder calculates a difference between a motion vector of the MVP candidate and a motion vector of the prediction unit, and encodes the difference and an index to identify the MVP candidate. A decoder decodes the difference, and calculates the motion vector of the prediction unit by adding the difference to the motion vector of the MVP candidate. | 07-12-2012 |
20120183080 | METHOD AND APPARATUS FOR A LOW COMPLEXITY TRANSFORM UNIT PARTITIONING STRUCTURE FOR HEVC - A method and apparatus for a low complexity transform unit partitioning structure for High Efficiency Video Coding (HEVC). The method includes determining prediction unit size of a coding unit, and setting the size of transform unit size of Y, U and V according to the prediction unit size of the coding unit. | 07-19-2012 |
20120230408 | Parsing Friendly and Error Resilient Merge Flag Coding in Video Coding - Methods and apparatus for parsing friendly and error resilient merge flag coding in video coding are provided. In some methods, in contrast to merging candidate list size dependent coding of the merge flag in the prior art, a merge flag is always encoded in the encoded bit stream for each inter-predicted prediction unit (PU) that is not encoded using skip mode. In some methods, in contrast to the prior art that allowed the merging candidate list to be empty, one or more zero motion vector merging candidates formatted according to the prediction type of the slice containing a PU are added to the merging candidate list if needed to ensure that the list is not empty and/or to ensure that the list contains a maximum number of merging candidates. | 09-13-2012 |
20120257678 | Parallel Motion Estimation in Video Coding - Methods for improved parallel motion estimation are provided that decouple the merging candidate list derivation and motion estimation for merge mode and skip mode and the advanced motion vector predictor (AMVP) candidate list construction from regular motion estimation to increase the coding quality in parallel motion estimation while meeting throughput requirements. This decoupling may be accomplished by modifying the availability rules for spatial motion data (SMD) positions for construction of the candidate lists. As part of the decoupling, largest coding units (LCUs) of a picture may be divided into non-overlapping parallel motion estimation regions (PMER) of equal size. Within a PMER, motion estimation for merge mode, skip mode, and normal inter-prediction mode may be performed in parallel for all the prediction units (PUs) in the PMER. | 10-11-2012 |
20120263231 | Temporal Motion Data Candidate Derivation in Video Coding - A method for derivation of a temporal motion data (TMD) candidate for a prediction unit (PU) in video encoding or video decoding is provided. The derived TMD candidate is for inclusion in an inter-prediction candidate list for the PU. The method includes determining a primary TMD position relative to a co-located PU in a co-located largest coding unit (LCU), wherein the co-located PU is a block in a reference picture having a same size, shape, and coordinates as the PU, and selecting at least some motion data of a secondary TMD position as the TMD candidate when the primary TMD position is in a bottom neighboring LCU or in a bottom right neighboring LCU of the co-located LCU, wherein the secondary TMD position is determined relative to the co-located PU. | 10-18-2012 |
20120320984 | Inter-Prediction Candidate Index Coding Independent of Inter-Prediction Candidate List Construction in Video Coding - Methods are provided for inter-prediction candidate index coding independent of the construction of the corresponding inter-prediction candidate list, i.e., a merging candidate list or an advanced motion vector predictor list. A maximum allowed number of inter-prediction candidates for an inter-prediction candidate list is used for encoding the inter-prediction candidate index in an encoded bit stream. The maximum allowed number may be pre-determined or may be selected by the encoder and encoded in the bit stream. A decoder may then decode the index using the maximum allowed number of inter-prediction candidates independent of the construction of the corresponding inter-prediction candidate list. | 12-20-2012 |
20130010055 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR CODING A SEREOSCOPIC NETWORK - In response to a stereoscopic image of first and second views, a maximum positive disparity is computed between the first and second views, and a minimum negative disparity is computed between the first and second views. Within a bit stream, at least the stereoscopic image, the maximum positive disparity, and the minimum negative disparity are encoded. | 01-10-2013 |
20130010069 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR WIRELESSLY CONNECTING A DEVICE TO A NETWORK - From a bit stream, at least the following are decoded: a stereoscopic image of first and second views; a maximum positive disparity between the first and second views; and a minimum negative disparity between the first and second views. In response to the maximum positive disparity violating a limit on positive disparity, a convergence plane of the stereoscopic image is adjusted to comply with the limit on positive disparity. In response to the minimum negative disparity violating a limit on negative disparity, the convergence plane is adjusted to comply with the limit on negative disparity. | 01-10-2013 |
20130016783 | Method and Apparatus for Coding Unit Partitioning - A method for coding unit partitioning in a video encoder is provided that includes performing intra-prediction on each permitted coding unit (CU) in a CU hierarchy of a largest coding unit (LCU) to determine an intra-prediction coding cost for each permitted CU, storing the intra-prediction coding cost for each intra-predicted CU in memory, and performing inter-prediction, prediction mode selection, and CU partition selection on each permitted CU in the CU hierarchy to determine a CU partitioning for encoding the LCU, wherein the stored intra-prediction coding costs for the CUs are used. | 01-17-2013 |
20130016787 | Fast Motion Estimation For Hierarchical Coding Structures - A method for motion estimation is provided that includes determining a first motion vector for a first child coding unit (CU) of a parent CU and a second motion vector for a second child CU of the parent CU, wherein the first child CU, the second child CU, and the parent CU are in a CU hierarchy, wherein the first and second child CUs are smallest size CUs in the CU hierarchy, and wherein a first motion search type is used to determine the first motion vector and the second motion vector, selecting the first and second motion vectors as candidate predictors for the parent CU, selecting a predictor for a prediction unit (PU) of the first parent CU from the candidate predictors, and refining the predictor using a second motion search type to determine a motion vector for the PU. | 01-17-2013 |
20130051454 | Sample Adaptive Offset (SAO) Parameter Signaling - A method for sample adaptive offset (SAO) filtering and SAO parameter signaling in a video encoder is provided that includes determining SAO parameters for largest coding units (LCUs) of a reconstructed picture, wherein the SAO parameters include an indicator of an SAO filter type and a plurality of SAO offsets, applying SAO filtering to the reconstructed picture according to the SAO parameters, and entropy encoding LCU specific SAO information for each LCU of the reconstructed picture in an encoded video bit stream, wherein the entropy encoded LCU specific SAO information for the LCUs is interleaved with entropy encoded data for the LCUs in the encoded video bit stream. Determining SAO parameters may include determining the LCU specific SAO information to be entropy encoded for each LCU according to an SAO prediction protocol. | 02-28-2013 |
20130077696 | Method and System for Lossless Coding Mode in Video Coding - A method for coding a video sequence is provided that includes encoding a portion of a picture in the video sequence in lossless coding mode, and signaling a lossless coding indicator in a compressed bit stream, wherein the lossless coding indicator corresponds to the portion of a picture and indicates whether or not the portion of the picture is losslessly coded. A method for decoding a compressed video bit stream is provided that includes determining that lossless coding mode is enabled, decoding a lossless coding indicator from the compressed video bit stream, wherein the lossless coding indicator corresponds to a portion of a picture in the compressed video bit stream and indicates whether or not the portion of the picture is losslessly coded, and decoding the portion of the picture in lossless coding mode when the lossless coding indicator indicates the portion of the picture is losslessly coded. | 03-28-2013 |
20130094592 | Virtual Memory Access Bandwidth Verification (VMBV) in Video Coding - A method is provided that includes determining a target picture virtual memory access (VMA) bandwidth rate, wherein the target picture VMA bandwidth rate indicates a maximum VMA bandwidth rate for motion compensation of a picture, and verifying the target picture VMA bandwidth rate for a compressed video bit stream. | 04-18-2013 |
20130101036 | Sample-Based Angular Intra-Prediction in Video Coding - A method for processing a prediction unit (PU) to generate predicted samples is provided that includes computing predicted samples for samples of the PU using sample-based angular intra-prediction (SAP) when lossless coding is enabled for the PU, and computing predicted samples for the samples of the PU using block-based angular intra-prediction when lossless coding is not enabled for the PU. Computation of the predicted using SAP includes determining an intra-prediction angle for the PU, and computing a predicted sample for each sample of the samples in the PU based on linear interpolation of two reference samples adjacent to the sample, wherein the two reference samples are selected according to the intra-prediction angle. | 04-25-2013 |
20130114715 | Delayed Duplicate I-Picture for Video Coding - A method is provided that includes receiving pictures of a video sequence in a video encoder, and encoding the pictures to generate a compressed video bit stream that is transmitted to a video decoder in real-time, wherein encoding the pictures includes selecting a picture to be encoded as a delayed duplicate intra-predicted picture (DDI), wherein the picture would otherwise be encoded as an inter-predicted picture (P-picture), encoding the picture as an intra-predicted picture (I-picture) to generate the DDI, wherein the I-picture is reconstructed and stored for use as a reference picture for a decoder refresh picture, transmitting the DDI to the video decoder in non-real time, selecting a subsequent picture to be encoded as the decoder refresh picture, and encoding the subsequent picture in the compressed bit stream as the decoder refresh picture, wherein the subsequent P-picture is encoded as a P-picture predicted using the reference picture. | 05-09-2013 |
20130128949 | Early Stage Slice Cap Decision in Video Coding - A method for making a slice cap decision during encoding of a video sequence in a video encoding pipe is provided that includes determining a prediction mode for a macroblock, computing an estimated encoded size of the macroblock based on an adaptive macroblock size estimation model, and making a slice cap decision for a current slice based on the estimated encoded macroblock size, wherein the slice cap decision is made prior to entropy coding the macroblock. | 05-23-2013 |
20130156097 | Adaptive Loop Filtering (ALF) for Video Coding - A method for adaptive loop filtering of a reconstructed picture in a video encoder is provided that includes determining whether or not sample adaptive offset (SAO) filtering is applied to the reconstructed picture, and using adaptive loop filtering with no offset for the reconstructed picture when the SAO filtering is determined to be applied to the reconstructed picture. | 06-20-2013 |
20130182759 | Method and Apparatus for Sample Adaptive Offset Parameter Estimation in Video Coding - A method for sample adaptive offset (SAO) filtering in a video encoder is provided that includes estimating SAO parameters for color components of a largest coding unit (LCU) of a picture, wherein estimating SAO parameters includes using at least some non-deblock-filtered reconstructed pixels of the LCU to estimate the SAO parameters, performing SAO filtering on the reconstructed LCU according to the estimated SAO parameters, and entropy encoding SAO information for the LCU in a compressed video bit stream, wherein the SAO information signals the estimated SAO parameters for the LCU. | 07-18-2013 |
20130188704 | Scalable Prediction Type Coding - A method for encoding a video sequence is provided that includes signaling in the compressed bit stream that a subset of a plurality of partitioning modes is used for inter-prediction of a portion of the video sequence, using only the subset of partitioning modes for prediction of the portion of the video sequence, and entropy encoding partitioning mode syntax elements corresponding to the portion of the video sequence, wherein at least one partitioning mode syntax element is binarized according to a pre-determined binarization corresponding to the subset of partitioning modes, wherein the pre-determined binarization differs from a pre-determined binarization for the least one partitioning mode syntax element that would be used if the plurality of partitioning modes is used for inter-prediction. | 07-25-2013 |
20130202051 | Sub-Pictures for Pixel Rate Balancing on Multi-Core Platforms - A method for decoding a compressed video bit stream in a video decoder to recover a video sequence, the video decoder including a plurality of decoder processing cores is provided. The method includes determining that a picture is encoded in the compressed bit stream as a pre-determined number of independently encoded sub-pictures, and dispatching a first encoded sub-picture of the pre-determined number of sub-pictures to a first decoder processing core of the plurality of decoder processing cores and a second encoded sub-picture of the pre-determined number of sub-pictures to a second decoder processing core of the plurality of decoder processing cores, wherein the first encoded sub-picture and the second encoded sub-picture are independently decoded in parallel on the respective first and second decoder processing cores. | 08-08-2013 |
20130223542 | Sample Adaptive Offset (SAO) Parameter Signaling - Techniques for signaling of sample adaptive offset (SAO) information that may reduce the coding rate for signaling such information in the compressed bit stream are provided. More specifically, techniques are provided that allow SAO information common to two or more of the color components to be signaled using one or more syntax elements (flags or indicators) representative of the common information. These techniques reduce the need to signal SAO information separately for each color component. | 08-29-2013 |
20130272415 | Memory Bandwidth Reduction for Motion Compensation in Video Coding - Motion compensation requires a significant amount of memory bandwidth, especially for smaller prediction unit sizes. The worst case bandwidth requirements can occur when bi-predicted 4×8 or 8×4 PUs are used. To reduce the memory bandwidth requirements for such smaller PUs, methods are provided for restricting inter-coded PUs of small block sizes to be coded only in a uni-predictive mode, i.e., forward prediction or backward prediction. More specifically, PUs of specified restricted sizes in bi-predicted slices (B slices) are forced to be uni-predicted. | 10-17-2013 |
20130329790 | Method and System for Reducing Slice Header Parsing Overhead in Video Coding - A method for encoding a picture of a video sequence in a bit stream that reduces slice header parsing overhead is provided. The method includes determining weighting factors that may be used for weighted prediction in encoding at least one slice of the picture, wherein a total number of the weighting factors is constrained to not exceed a predetermined threshold number of weighting factors, wherein the threshold number is less than a maximum possible number of weighting factors, and signaling weighted prediction parameters including the weighting factors in a slice header in the bit stream. | 12-12-2013 |
20140044193 | A GUARANTEED-RATE TILED MEMORY-DATA COMPRESSION - A method of compressing digital image data is provided that includes, for each image data block in a plurality of image data blocks in the digital image data, transforming image data in the image data block to convert the image data to a low-frequency coefficient and a plurality of high-frequency coefficients, computing a predicted low-frequency coefficient for the image data block based on at least one neighboring image data block in the plurality of image data blocks, computing a residual low-frequency coefficient based on the predicted low-frequency coefficient and the low-frequency coefficient, quantizing the plurality of high-frequency coefficients, and entropy coding the residual low-frequency coefficient and the quantized high-frequency coefficients. | 02-13-2014 |
20140185676 | LINE-BASED COMPRESSION FOR DIGITAL IMAGE DATA - A method of compressing digital image data is provided that includes selecting an entropy code for encoding a line of pixels in the digital image data, wherein the entropy code is selected from a plurality of variable length entropy codes, using spatial prediction to compute a pixel predictor and a pixel residual for a pixel in the line of pixels, and selectively encoding the pixel residual using one of the entropy code or run mode encoding. | 07-03-2014 |