262 results about "Coding tree unit" patented technology

The invention discloses an HEVC intra-frame prediction quick mode selection method based on texture analysis. According to the method, before intra-frame prediction is carried out on an encoding tree unit, the main texture direction and the texture complexity of each 4*4 unit in the encoding tree unit are determined according to the sum of absolute values of gradients in the horizontal direction, the vertical direction, the lower left direction and the lower right direction, and division of the current encoding tree unit is determined according to the principle that a larger encoding unit is adopted in a texture smooth area and a smaller encoding unit is adopted in a texture complex area. During prediction, according to the main texture direction of the prediction unit, a plurality of prediction modes with least probability are eliminated, and rough mode selection and rate-distortion optimization mode selection are carried out according to an HEVC encoding standard. According to the HEVC intra-frame prediction quick mode selection method based on texture analysis, on the premise that encoding quality is guaranteed, the encoding speed can be obviously improved.

Techniques and systems are provided for encoding and decoding video data. For example, a method of encoding video data including a plurality of pictures is described. The method includes performing intra-picture prediction on a block of one of the pictures to generate a prediction unit. Performing the intra-picture prediction includes selecting a reference block for intra-block copy prediction of a coding tree unit (CTU). The reference block is selected from a plurality of encoded blocks, and blocks within the CTU encoded with bi-prediction are excluded from selection as the reference block. Performing the intra-picture prediction further includes performing intra-block copy prediction with the selected reference block to generate the prediction unit. The method also includes generating syntax elements encoding the prediction unit based on the performed intra-picture prediction.

The invention provides a screen image compression device and a compression method thereof. A plurality of sets of complemental coding tool combinations are used by the compression device, a coding unit with a certain pixel is taken as a coding unit, to a same coding unit, a plurality of sets of coding tool combinations are used simultaneously to carry out precoding, and a combination with an optimal rate-distortion characteristic is selected to compress the coding unit. Simultaneously, the invention provides a decompression apparatus and a decompression method which are corresponding to the compression device and the compressing method, through analyzing input compression code stream data, a decoding tool combination corresponding to the data is selected to decode the data and carry out image reconstruction, and a screen image compression effect of the present invention is raised substantially compared with the prior art.

A method of encoding a coding tree unit in a video bitstream. A plurality of candidate configurations are formed for the coding tree unit, each of the candidate configurations having a variation of at least one of a set of partitioning modes and encoding parameters. A candidate configuration is selected from the plurality of candidate configurations based on a predetermined maximum bit rate for the coding tree unit, the selected candidate configuration having a size within the predetermined maximum bit rate. The coding tree unit is encoded using the selected candidate configuration.

The application relates to a loop filtering method, a loop filtering device, a piece of electronic equipment and a readable medium. The loop filtering method includes the following steps: setting a virtual boundary outside the actual boundary of a coding tree unit according to the size and shape of a filter; filling the gap between the actual boundary and the virtual boundary with virtual pixel samples; and using the virtual pixel samples instead of the pixels beyond the actual boundary of the coding tree unit to carry out loop filtering on the multiple pixels in the coding tree unit. According to the method, a virtual boundary is set outside the actual boundary, and virtual pixel samples are set between the virtual boundary and the actual boundary, so that virtual pixel samples can be used in adaptive loop filtering, and the problem of data dependence between coding tree units is solved.

The invention relates to an HEVC (High Efficiency Video Coding) intraframe coding mode selection method based on texture division features. The method includes steps of 1, inputting a CTU (Coding Tree Unit) with a to-be-selected coding mode; 2, performing texture feature analysis on original pixel brightness value of the current CTU and obtaining texture division marks of CUs of different sizes and a texture feature value of a 32*32 CU (Coding Unit) through calculation; 3, utilizing the texture division marks and the texture feature values of CUs, predicting a depth range of the current CTU and calculating an early termination coding division mark of the CUs and an early termination predication division mark of a PU (Predication Unit);4, utilizing the depth range of the current CTU, the early termination coding division mark of the CUs and the early termination predication division mark of the PU, implementing quadtree division of the current CTU. According to the invention, in a condition of maintaining good coding rate distortion performance, HEVC intraframe coding processing time is reduced effectively and at the same time, a comparatively good parallel treatment characteristic is achieved.

The invention discloses a learning-based high efficiency video coding method. The method comprises the following steps: coding a video sequence by a high efficiency video coder, and extracting feature vectors corresponding to coding unit blocks; inputting the extracted feature vectors and an optimal coding unit size into a three-value-output learning machine, and building a learning model; adding an early-abort strategy structure into a selection process of coding unit sizes in the high efficiency video coder, executing a skip mode current block and a merge mode current block firstly, and extracting feature vectors corresponding to corresponding current coding; inputting the feature vectors into a learned learning machine model, outputting a prediction value, and executing the current coding unit size according to the corresponding early-abort strategy structure till all coding unit layers in coding tree units are coded; and performing repeated execution till the coding tree units in all video frames are coded. By adoption of the method, an optimal coding process can be output correspondingly according to a rate-distortion cost and calculation complexity; the learning performance and classifying performance of a classifier are improved; and the coding efficiency of video coding is increased.

A two-stage context adaptive binary arithmetic coding (CABAC) parser is provided to efficiently transcode an input video bitstream that is partitioned into tiles into a non-tiled based video bitstream. A picture of the input video bitstream is partitioned into one or more tiles, each of which has multiple coding tree units (CTUs) according to the HEVC standard. The two-stage CABAC parser parses the input video bitstream in tile scan order in the first stage and generates a list of identified CTUs, whose CABAC state data are saved for the second stage parsing. In the second stage parsing, the two-stage parser parses the same input video bitstream in raster scan order using the saved CABAC state data of the identified CTUs.

The present invention relates to an image encoding / decoding method. The image decoding method includes splitting a coding tree unit (CTU) into at least one coding unit (CU) according to a block splitting structure and performing CU-based decoding, in which the block partition structure is configured such that at least one of binary tree splitting and ternary tree splitting is performed after quadtree splitting is performed.

Provided is a method for decoding a picture, performed by a decoding apparatus. The method includes deriving neighboring luma reference samples of a luma block; deriving neighboring chroma reference samples for a chroma block when an intra prediction mode of the chroma block is a cross-component linear model (CCLM) mode; deriving neighboring luma reference samples of a luma block corresponding to the chroma block and luma samples in the luma block; deriving down-sampled neighboring luma reference samples and down-sampled luma samples by down-sampling the neighboring luma reference samples and the luma samples; deriving a linear model parameter based on the down-sampled neighboring luma reference samples and the neighboring chroma reference samples; generating prediction samples for the chroma block based on the linear model parameter and the down-sampled luma samples of the luma block; and reconstructing the chroma block based on the prediction samples for the chroma block, wherein the neighboring luma reference samples includes top neighboring luma reference samples located at the upper side of a top boundary of the luma block, and left neighboring luma reference samples located at the left side of a left boundary of the luma block, and wherein when the top boundary of the luma block overlaps with a boundary of a coding tree unit (CTU), the number of the top neighboring luma reference samples used for deriving the down-sampled neighboring luma reference samples among the neighboring luma reference samples is less than that of the left neighboring luma reference samples used for deriving the down-sampled neighboring luma reference samples.

Systems and methods which provide a joint machine learning and game theory modeling (MLGT) framework for video coding rate control (RC) are described. A machine learning based R-D model classification scheme may be provided to facilitate improved R-D model prediction accuracy and a mixed R-D model based game theory approach may be implemented to facilitate improved RC performance. For example, embodiments may provide inter frame Coding Tree Units (CTUs) level bit allocation and RC optimization in HEVC. Embodiments provide for the CTUs being classified into a plurality of categories, such as by using a support vector machine (SVM) based multi-classification scheme. An iterative solution search method may be implemented for the mixed R-D models based bit allocation method. Embodiments may additionally or alternatively refine the intra frame QP determination and the adaptive bit ratios among frames to facilitate improving the coding quality smoothness.

A video coding system, and a method of operation thereof, includes: a source input module for receiving a frame from a video source; and a picture process module, coupled to the source input module, for generating a reference coding unit in the frame; for generating an intra copy motion vector pointing to the reference coding unit within a search range, wherein the search range does not include an upper coding tree unit of the frame; for generating a current coding unit based on the intra copy motion vector; and for generating a video bitstream based on the current coding unit for a video decoder to receive and decode for displaying on a device.

The invention relates to an HEVC interframe coding quick mode selection method, comprising the following steps of: 1, inputting frame video data; 2, selecting a coding tree unit (CTU) to be estimated; 3, calculating the depth estimation range of the current CTU; 4, selecting a CU to be estimated in the current CTU; 5, estimating a large size interframe prediction unit (PU) mode; 6, selecting to estimate a small size interframe PU mode or not; 7, estimating a symmetrical interframe PU mode; 8, selecting to estimate an asymmetrical interframe PU mode or not; 9, estimating an interframe PU mode; 10, selecting the optimum PU mode of the current CU; 11, ending the judgment of the CU partition; 12, repeating the steps 4 to the steps 11 until estimation of all CUs is completed; and 13, repeating the steps 2 to the steps 12 until estimation of all CTUs in the current frame is completed. According to the HEVC interframe coding quick mode selection method, the coding time of the HEVC can be effectively reduced, and meanwhile the good rate-distortion performance is kept.

The invention discloses a low-complexity method for selecting HEVC (High Efficiency Video Coding) coding multiple reference frames. The method comprises the following steps of inputting an original coding sequence, taking a code tree cell as the unit, and selecting the optimal reference frame for each coding cell through the operations of a, if the parent coding unit of the current coding unit is in an SKIP mode, taking the optimal reference frame of all forecast cells in the current coding unit as the optimal reference frame of the parent coding unit, and b, if the parent coding unit of the current coding unit is not in the SKIP mode, firstly selecting multiple reference frames for forecast cells in an inter-frame dividing mode of 2N*2N of the current coding unit, and calculating the rate distortion cost of each reference frame in the 2N*2N inter-frame dividing mode, gathering all reference frames of which the rate distortion costs are lower than a threshold in a reference frame set, and selecting the optimal reference frame for the rest inter-frame dividing modes in the reference frame set. The low-complexity method is capable of remarkably speeding up HEVC video coding.

The invention discloses a rapid high efficiency video coding (HEVC) method based on depth and space-time relevancy of coding units. The rapid HEVC method includes the following steps of (1) inputting an original coding sequence; (2) extracting the depth of a coded coding unit; (3) if the depth of a current coding unit is smaller than a depth threshold value, using a depth relationship of two adjacent coding units in a prior frame to narrow a depth search range of the current coding unit; (4) searching the depth within the depth search range obtained in step (3) according to the increasing sequence and ending the depth search unit the maximum depth is searched; (5) determining an optimum coding tree unit partition according to the depth searched in step (4), and subsequently performing HEVC. According to the HEVC method, the HEVC can be obviously accelerated, better rate-distortion properties can be guaranteed, and higher practicability is achieved.

The invention discloses a method for low-complexity video transcoding from H.264 to HEVC based on a statistic analysis. The method comprises the first step of decoding original H. 264 video streaming, wherein in the process of decoding, the macro block coding bit number, the macro block coding mode and the motion vector field of a current decoding frame are extracted; the second step of mapping areas covered by HEVC coding tree units to all macro blocks of the current decoding frame, calculating the coding complexity of each area and determining the searching depth ranges of each HEVC coding tree unit according to the coding complexity; the third step of carrying out motion estimation in a level-by-level mode according to the corresponding searching depth range of each coding tree unit, and carrying out corresponding HEVC recoding. By means of the method, the speed of low-complexity video transcoding from H.264 to HEVC can be obviously improved, low rate-distortion is obtained, and the method is very high in practicability.

The invention discloses an HEVC (High Efficiency Video Coding) rate control method based on rate distortion optimization and mainly aims at solving the problem that the quality of a video reconstructed by the existing rate control method of video coding standards HEVC is poor. The method is realized by the following steps of (1) setting encoder parameters; (2) sequentially reading each image group and carrying out rate control over each frame of each image group; (3), for each frame, calculating the quantitive parameter of the frame and coding if rate control is not needed for a coding tree unit layer, and if rate control is needed, calculating the target bit of the frame and carrying out rate control over the coding tree unit layer; and (4) sequentially calculating the quantitive parameter of each coding tree unit and coding by a quantitive parameter calculating method based on rate distortion optimization and realizing rate control over the coding tree unit layer. The quality of the video reconstructed by the video coding standards HEVC is improved by the method. The method can be used for videos on demand, remote education, telemedicine, video conferences, videophones, stream media and the like.

A video encoding method includes receiving a source video frame, dividing the source video frame into a coding tree unit, determining a coding unit from the coding tree unit, determining a correlation between components of the coding unit, enabling or disabling a coding mode of the coding unit, determining whether to evaluate a size of a transform unit for an enabled coding mode, and determining a transform unit of the coding unit for the enabled coding mode, wherein the size of the coding unit is defined by a number (N) of samples.

The invention discloses a video transcode method from H264 to HEVC based on region feature analysis. The method comprises the following steps that decoding is carried out on an original H.264 video stream, and macro block encoding bit numbers, macro block encoding modes and motion vector fields of a current decoding frame are extracted; areas covered by HEVC encoding tree units are made to correspond to macro blocks of the current decoding frame, encoding complexity of each area is calculated, and the searching depth range of each HEVC encoding tree unit is determined; motion estimation is carried out on each encoding tree unit level by level according to corresponding searching depth range, and if the mode of a predicted unit is an Inter mode, region feature analysis is carried out, and a division mode is obtained; motion search is carried out on each predicted unit according to various reserved division modes, and the division mode with the smallest rate-distortion and motion vectors are selected to carry out HEVC recoding. According to the method, on the premise that almost the same rate-distortion is kept, transcoding speed is greatly improved.

The invention discloses a method for quality scalable HEVC (high efficiency video coding), and belongs to the technical field of video coding. According to the method, the relevancy of the coding depth of a base layer and the coding depth of a reinforcement layer is used. When coding of the reinforcement layer is conducted, the actual coding depths of coding tree units of the base layer corresponding to all coding tree units of the reinforcement layer are used as the maximum coding depths of all the coding tree units of the reinforcement layer for coding. According to the method, the relevancy between corresponding CTU coding depths in a front frame and a rear frame is also used for further lowering the calculating complexity of a base layer coding algorithm. Compared with the prior art, under the premise that the image quality after coding can be guaranteed, the calculating complexity of coding is effectively lowered, and the real-time performance of the coding process is improved.

The invention provides a video decoding data storage method and a calculation method of motion vector data. The video decoding data storage method includes setting a reference frame queue table in a static random access memory, storing basic information of a plurality of reference frames in the reference frame queue table, wherein each unit of the reference frame queue table stores index information corresponding to one reference frame in a decoding buffer area; storing a plurality of groups of frame buffer information corresponding to the index information in the decoding buffer area, wherein each group of frame buffer information contains frame display sequence data and motion vector storage address information; storing the motion vector storage of each reference frame in a dynamic random access memory, wherein the motion vector storage address information is address information of the motion vector data of a coding tree unit of corresponding blocks of the reference frames stored in the dynamic random access memory. The video decoding data storage method and the calculation method of the motion vector data can improve the video decoding efficiency and save hardware expense and bandwidth resources occupied during video decoding.

The invention discloses a HEVC fast sample point self-adaptive offset method based on a dominant edge direction. The method comprises the following steps: step one, extracting the dominant edge direction of each CTU (coding tree unit); step two, determining an optimal boundary offset mode and a offset value thereof of the CTU; step three, computing a relative ratio distortion cost of other SAO offset way; step four, determining an optimal SAO mode of the CTU. The dominant edge direction of each CTU is extracted as the optimal EO mode of the CTU, and then the optimal mode is judged through the formula Cost=Distortion+lambda*Bitrate after traversing the optimal EO mode, the BO mode, the parameter merge mode, and the non-offset mode. The complexity in the SAO mode determination process is reduced through the adoption of texture information of an image, and the SAO encoding running time of the HEVC is saved.

In some aspects, the disclosure is directed to methods and systems for reducing memory utilization and increasing efficiency during affine merge mode for versatile video coding by utilizing motion vectors stored in a motion data line buffer for a prediction unit of a second coding tree unit neighboring a first coding tree unit to derive control point motion vectors for the first coding tree unit.

The invention discloses a rapid judgment method and system for multifunctional video coding and a storage medium. The method comprises: calculating texture values of input coding tree units; carryingout quadtree division on the input coding tree unit to obtain four coding units; calculating texture difference values of a plurality of sub-parts in each coding unit, and carrying out skip judgment of a division mode on the coding unit according to the calculated texture difference values and a preset threshold value; adding the division modes which are judged to be not skipped in the division modes into a candidate list; and dividing the coding unit according to the division mode in the candidate list. According to the method, the division mode skip judgment of the coding unit is carried outby utilizing the textural features of each sub-part in the coding unit, the invalid division operation of the QTMT can be reduced through the skip judgment, and the coding efficiency is improved; themethod and system are suitable for QTMT partitioning schemes of all VCC partitioning tree types, and is wide in applicability. The method and system can be widely applied to the field of video coding.

The invention discloses a multifunctional video coding intra-frame division method and system and a storage medium. The multifunctional video coding intra-frame division method comprises the followingsteps: extracting edge features of a coding tree unit by adopting an edge extraction algorithm; obtaining vertical edge texture features and horizontal edge texture features of a coding unit in the current coding tree unit according to the edge features of the current coding tree unit; and according to the vertical edge texture features and the horizontal edge texture features of the coding unitsin the current coding tree unit, performing division decision of the coding units. According to the multifunctional video coding intra-frame division method, edge texture features of the coding unitsare utilized to skip some division modes, so that the coding time is reduced, and the coding efficiency is improved; and according to the vertical edge texture features and the horizontal edge texture features of the coding units in the current coding tree unit, a horizontal binary division mode and a horizontal ternary division mode or a vertical binary division mode and a vertical ternary division mode are skipped, so that the coding quality is higher. The multifunctional video coding intra-frame division method can be widely applied to the field of video coding.

The invention discloses a multifunctional video coding inter-frame division method and system and a storage medium. The method comprises the following steps of: executing the next step when it is determined that a coding frame of a current coding tree unit is an intra-frame coding frame or a first ratio is less than or equal to a first threshold value; extracting and calculating vertical edge texture features and horizontal edge texture features of the current coding unit; and performing division decision of the current coding unit according to the vertical edge texture features and the horizontal edge texture features of the current coding unit. According to the invention, during inter-frame predictive coding, the relative size of the first ratio and whether the coding frame is an intra-frame coding frame or not or the edge texture feature of the current coding unit are used for skipping some division modes, so that the coding efficiency is improved; at least three division modes areselected for recursive division according to the vertical edge texture features and the horizontal edge texture features of the current coding unit, the BD-rate is smaller, and the coding performanceis better. The method can be widely applied to the field of video coding.

A method and apparatus for adaptive de-blocking filter are disclosed. One or more parameters associated with a de-blocking filter are determined. De-blocking filter using the derived parameters are then applied to reconstructed blocks. Each set of parameters is used for each picture, slice, coding tree unit (CTU) or CU (coding unit). The parameters can be signalled in VPS (video parameter set), SPS (sequence parameter set), PPS (picture parameter set), slice header, CTU (coding tree unit) or CU (coding unit) of the video bitstream. The parameters correspond to one or more values used as thresholds, clipping boundaries, or both the thresholds and clipping boundaries for the de-blocking filter. In one embodiment, the parameters for the current picture are determined using a training processusing a current coded picture a previous coded picture as training data.

The invention relates to a HEVC (High Efficiency Video Coding)-based coding method of layered depth video residual layer data. The method comprises the following specific steps: S1: carrying out parameter regulation when a LDV (Layered Depth Video) is generated to filter the useless residual data of a background area, and meanwhile, properly increasing the residual data; S2: carrying out residual layer block calibration preprocessing: in the LDV, the distribution of the residual data is unfriendly to a current coding frame, and in order to keep consistent with the quadtree partitioning principle of CTU (Coding Tree Unit) in the HEVC and do not change division situations of each CU (Coding Unit) block, a grid with the size of 8*8 is adopted to carry out block calibration processing; and S3: carrying out residual layer coding: the block is divided by the quadtree principle by the HEVC, and an improved CU division principle and a method for selecting the proper size of the CU are provided since the shape of the residual data does not completely conform to the CU block of the HEVC. When the method is used for coding the LDV residual data, a coding bit number can be lowered, and meanwhile, the artifacts of synthetic virtual viewpoints can be reduced.

A method of IntraBC coding using restricted reference area is disclosed. A reference block is selected from an available ladder-shaped reference area comprising previously processed blocks before the current working block in the current CTU row and previously processed blocks in one or more previous CTU rows. A location of a last previously processed block of a second previous CTU row that is one CTU row farther away from the current CTU row than a first previous CTU row is always in a same vertical location or after a same vertical position of a last previously processed block of the first previous CTU row. The current picture may be partitioned into multiple CTU rows for applying wavefront parallel processing (WPP) on the multiple CTU rows, where the current working block corresponds to a current working block. Similar restrictions may also be applied to slice / tile-based parallel processing.

An apparatus and method for determining a discrete cosine transform (DCT) size based on a transform depth are disclosed herein. The apparatus for determining a DCT size based on a transform depth includes a prediction mode determination unit, a transform unit (TU) generation unit, and a DCT performance unit. The prediction mode determination unit determines a prediction mode in order to determine a DCT size at the root location of a coding unit (CU) present in a coding tree unit (CTU). The transform unit (TU) generation unit partitions the CU into transform units (TUs) based on a residual quad tree (RQT). The DCT performance unit performs a DCT based on the TUs.