Merge candidate reorder based on global motion vector

Abstract

To provide merge candidate recorder based on a global motion vector.SOLUTION: A decoder includes circuitry configured to: receive a bitstream; construct, for a current block, a motion vector candidate list including a motion vector candidate having motion information that characterizes a global motion vector; reorder the motion vector candidate list such that the motion vector candidate having the motion information that characterizes the global motion vector is first in the reordered motion vector candidate list; and reconstruct pixel data of the current block, so as to use the reordered motion vector candidate list. Related apparatus, systems, techniques and articles are also described.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 856,339, filed June 3, 2019, and entitled "MERGE CANDIDATE REORDER BASED ON GLOBAL MOTION VECTOR," which is incorporated by reference in its entirety.

[0002] The present invention relates generally to the field of video compression. In particular, the present invention is directed to reordering of fusion candidates based on global motion vectors. [Background technology]

[0003] A video codec may include electronic circuitry or software that compresses or decompresses digital video. It can convert uncompressed video into a compressed format, or vice versa. In the context of video compression, a device that compresses video (and / or performs some function thereof) may typically be called an encoder, and a device that decompresses video (and / or performs some function thereof) may be called a decoder.

[0004] The format of the compressed data can conform to standard video compression specifications. The compression can be lossy, in that the compressed video lacks certain information present in the original video. Consequences of this can include that the decompressed video may have lower quality than the original uncompressed video, because there is insufficient information to accurately reconstruct the original video.

[0005] There may be a complex relationship between video quality, the amount of data used to represent the video (e.g., determined by bit rate), the complexity of the encoding and decoding algorithms, sensitivity to data loss and errors, ease of organization, random access, end-to-end delay (e.g., latency), and the like.

[0006] Motion compensation can include an approach for predicting a video frame or a portion thereof given a reference frame, such as a previous and / or future frame, by considering the motion of the camera and / or objects in the video. This can be employed in encoding and decoding video data for video compression, for example, in encoding and decoding using the Motion Picture Experts Group (MPEG)-2 (also referred to as Advanced Video Coding (AVC) and H.264) standard. Motion compensation can describe a picture in terms of a transformation of a reference picture to a current picture. The reference picture can be from the future, as compared to the current picture, that is temporally earlier, as compared to the current picture. Compression efficiency can be improved when images can be accurately synthesized from previously transmitted and / or stored images. Summary of the Invention [Means for solving the problem]

[0007] In one aspect, a decoder includes circuitry configured to receive a bitstream, construct a motion vector candidate list for a current block including motion vector candidates having motion information characterizing a global motion vector, sort the motion vector candidate list such that the motion vector candidate having motion information characterizing the global motion vector is first in the sorted motion vector candidate list, reconstruct pixel data for the current block, and use the sorted motion vector candidate list.

[0008] In another aspect, a method includes receiving, by a decoder, a bitstream; constructing a motion vector candidate list for a current block including motion vector candidates having motion information characterizing a global motion vector; sorting the motion vector candidate list such that the motion vector candidate having motion information characterizing the global motion vector is first in the sorted motion vector candidate list; and reconstructing pixel data for the current block using the sorted motion vector candidate list.

[0009] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. The present invention provides, for example, the following: (Item 1) A decoder, the decoder comprising circuitry; The circuitry includes: receiving a bitstream; constructing, for the current block, a motion vector candidate list including motion vector candidates having motion information characterizing a global motion vector; reordering the motion vector candidate list such that the motion vector candidate having the motion information characterizing the global motion vector is first in the reordered motion vector candidate list; reconstructing pixel data of the current block and using the reordered motion vector candidate list; A decoder configured to: (Item 2) Item 2. The decoder of item 1, wherein the decoder configured to determine global motion is designated for a current frame that includes the current block. (Item 3) 2. The decoder of claim 1, wherein the reordering includes inserting a first global motion vector candidate into a fusion candidate list. (Item 4) 2. The decoder of claim 1, wherein building the motion vector candidate list includes the reordering. (Item 5) 2. The decoder of claim 1, wherein the global motion vectors include control point motion vectors. (Item 6) 6. The decoder of claim 5, wherein the control point motion vector is a translational motion vector. (Item 7) 6. The decoder of claim 5, wherein the control point motion vectors are vectors of a four-parameter affine motion model. (Item 8) 6. The decoder of claim 5, wherein the control point motion vectors are vectors of a six-parameter affine motion model. (Item 9) The decider is an entropy decoder processor configured to receive the bitstream and decode the bitstream into quantized coefficients; an inverse quantization and inverse transform processor, the inverse quantization and inverse transform processor configured to process the quantized coefficients including performing an inverse discrete cosine; A deblocking filter; A frame buffer; Intra prediction processor Item 1. The decoder of item 1, further comprising: (Item 10) 2. The decoder of claim 1, wherein the current block forms part of a quadtree+binary decision tree. (Item 11) 2. The decoder of claim 1, wherein the current block is a coding tree unit. (Item 12) 2. The decoder of claim 1, wherein the current block is a coding unit. (Item 13) 2. The decoder of claim 1, wherein the current block is a prediction unit. (Item 14) 1. A method comprising: receiving, by a decoder, a bitstream; constructing, for the current block, a motion vector candidate list including motion vector candidates having motion information characterizing a global motion vector; reordering the motion vector candidate list such that the motion vector candidate having the motion information characterizing the global motion vector is first in the reordered motion vector candidate list; reconstructing pixel data of the current block and using the reordered motion vector candidate list; A method comprising: (Item 15) Item 15. The method of item 14, wherein the decoder configured to determine global motion is indicated for a current frame that includes the current block. (Item 16) Item 15. The method of item 14, wherein the reordering includes inserting a first global motion vector candidate into the fusion candidate list. (Item 17) 15. The method of claim 14, wherein constructing the motion vector candidate list includes the sorting. (Item 18) Item 15. The method of item 14, wherein the global motion vectors include control point motion vectors. (Item 19) 20. The method of claim 18, wherein the control point motion vector is a translational motion vector. (Item 20) 20. The method of claim 18, wherein the control point motion vectors are vectors of a four-parameter affine motion model. (Item 21) 20. The method of claim 18, wherein the control point motion vectors are vectors of a six-parameter affine motion model. (Item 22) The decoder comprises: an entropy decoder processor configured to receive the bitstream and decode the bitstream into quantized coefficients; an inverse quantization and inverse transform processor, the inverse quantization and inverse transform processor configured to process the quantized coefficients including performing an inverse discrete cosine; A deblocking filter; A frame buffer; Intra prediction processor Item 15. The method of item 14, further comprising: (Item 23) Item 15. The method of item 14, wherein the current block forms part of a quadtree+binary decision tree. (Item 24) Item 15. The method of item 14, wherein the current block is a coding tree unit. (Item 25) Item 15. The method of item 14, wherein the current block is a coding unit. (Item 26) Item 15. The method of item 14, wherein the current block is a prediction unit. (Item 27) Item 15. The method of item 14, wherein the global motion vector is characterized by a header of the bitstream, the header including a picture parameter set (PPS) or a sequence parameter set (SPS). (Item 28) Item 15. The method according to item 14, wherein the motion vector candidate list is a fused vector candidate list. [Brief description of the drawings]

[0010] For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown in the drawings.

[0011] [Figure 1]FIG. 1 is a diagram illustrating motion vectors of an example frame with global and local motion. [Diagram 2] FIG. 2 is a block diagram illustrating the spatial candidates considered in the approach to fusion modes. [Diagram 3] FIG. 3 is a block diagram illustrating spatial candidates and associated global motion vectors considered in an approach to fusion modes. [Figure 4] FIG. 4 illustrates three example motion models that may be utilized for global motion, including their index values ​​(0, 1, or 2). [Diagram 5] FIG. 5 is a process flow diagram according to some example implementations of the present subject matter. [Figure 6] FIG. 6 is a system block diagram of an example decoder in accordance with some example implementations of the present subject matter. [Figure 7] FIG. 7 is a process flow diagram according to some example implementations of the present subject matter. [Figure 8] FIG. 8 is a system block diagram of an example encoder in accordance with some example implementations of the present subject matter. [Figure 9] FIG. 9 is a block diagram of a computing system that may be used to implement any one or more of the methodologies disclosed herein and any one or more portions thereof.

[0012] The drawings are not necessarily to scale and may be illustrated by phantom lines, schematic representations, and partial views. In some instances, details that are not necessary for an understanding of the embodiments or that make other details difficult to perceive may be omitted. Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Global motion in a video refers to motion that occurs in the entire frame. Global motion can be caused by camera motion, e.g., camera panning and zooming typically produces motion in a frame that can affect the entire frame. Motion that is present in a portion of a video can be referred to as local motion. Local motion can be caused by a moving object in a scene, e.g., an object moving from left to right in a scene. A video can contain a combination of local and global motion. Some implementations of the present subject matter can provide for building a fusion candidate list based on global motion vectors, which can signal candidates and improve compression by reducing the bits required to code motion vector differences.

[0014] FIG. 1 is a diagram illustrating motion vectors of an example frame 100 with global and local motion. Frame 100 includes several blocks of pixels, illustrated as squares, and their associated motion vectors, illustrated as arrows. Squares (e.g., blocks of pixels) with arrows pointing up and to the left may indicate blocks with motion that may be considered to be global motion, and squares with arrows pointing in the other direction (indicated by 104) may indicate blocks with local motion. In the illustrated example of FIG. 1, many of the blocks have the same global motion. Signaling global motion in a header, such as a picture parameter set (PPS) or sequence parameter set (SPS), and using the signal global motion may reduce the motion vector information required by blocks, resulting in improved prediction.

[0015] As an example, still referring to FIG. 1, a simple translational motion is expressed as a two-component MV x , M.V. yMore complex motions, such as rotation, magnification, and warping, may be described using affine motion vectors, where an "affine motion vector" as used in this disclosure is a vector that describes a uniform displacement of a video picture and / or a set of pixels or points represented within a picture, such as a set of pixels illustrating an object moving across a field of view in a video without changing its apparent shape during the motion. Some approaches to video encoding and / or decoding may use a four-parameter or six-parameter affine model for motion compensation in inter-picture coding. For example, a six-parameter affine motion can be described as follows: x'=ax+by+c y'=dx+ey+f The four-parameter affine motion can be described as follows. x'=ax+by+c y'=-bx+ay+f where (x,y) and (x',y') are pixel locations in the current and reference pictures, respectively, and a, b, c, d, e, and f are the parameters of the affine motion model.

[0016] Continuing with reference to FIG. 1, block-based and / or sub-block-based affine transform motion compensation prediction may alternatively or additionally be applied. The affine motion field of a block and / or sub-block may be described by motion information of two control points (4 parameters) or three control point motion vectors (6 parameters). In a four-parameter affine motion model, a motion vector at a sample location (x,y) within a block may be derived as follows: [ka]

[0017] For a six-parameter affine motion model, the motion vector at a sample location (x,y) within a block can be derived as follows: [ka] In the formula, (mv 0x ,mv 0y ) is the motion vector of the upper left corner control point, and (mv 1x ,mv 1y ) is the motion vector of the control point in the upper right corner, and (mv 2x ,mv 2y ) is the motion vector of the lower-left control point.

[0018] To simplify the motion compensation prediction, a block-based affine transformation prediction may be applied. As an illustrative example, to derive a motion vector for each 4×4 luma sub-block, the motion vector of the center sample of each sub-block may be calculated according to the above equation and rounded to 1 / 16 fractional accuracy. Then, a motion compensation interpolation filter may be applied to generate a prediction of each sub-block with the derived motion vector. Still continuing with the example, the sub-block size of the chroma component may also be set to 4×4. The motion vector of a 4×4 chroma sub-block may be calculated as the average of the MVs of the four corresponding 4×4 luma sub-blocks.

[0019] As in the case of translational motion inter prediction, there are also two affine motion inter prediction modes, namely, affine fusion mode and affine AMVP mode. Still referring to FIG. 1, parameters used to describe affine motion may be signaled to a decoder to apply affine motion compensation at the decoder. In some approaches, the motion parameters may be signaled explicitly or by signaling translational control point motion vectors (CPMVs) and then deriving affine motion parameters from the translational motion vectors. Two control point motion vectors (CPMVs) may be utilized to derive affine motion parameters for a four-parameter affine motion model, and three control point translational motion vectors (CPMVs) may be utilized to obtain parameters for a six-parameter motion model. Signaling affine motion parameters using control point motion vectors may enable the use of efficient motion vector coding methods to signal affine motion parameters.

[0020] Continuing with reference to FIG. 1, some blocks may share the same motion vector information. For example, two blocks corresponding to an object moving across the screen may share the same motion vector because they both relate to the same object. In such a scenario, some approaches to motion compensation may utilize a fusion mode in which neighboring blocks may share a motion vector and motion information may be encoded in the bitstream for a first block, and a second block may inherit (e.g., fuse with) the motion information from the first block. During encoding, a fusion list may be constructed containing available fusion candidates. The fusion candidates may be selected from the constructed fusion list, and an index into the fusion list may be signaled in the bitstream. During decoding, a fusion list may again be constructed from the available fusion candidates, and an index signaled in the bitstream may be used to indicate the block with which the current block will inherit (e.g., fuse with) the motion information.

[0021] FIG. 2 is a block diagram 200 illustrating an example embodiment of spatial candidates that may be considered in a typical approach to a fusion mode, such as that implemented for HEVC. A current block 204 may include a coding unit or a prediction unit. The spatial fusion candidates may include A0, A1, B0, B1, and B2. A0, A1, B0, and B2 may include neighboring prediction and / or coding units. When generating a fusion candidate list, the list may be constructed by considering up to four spatial fusion candidates derived from five spatial neighboring blocks, as shown in FIG. 2. In this example, a threshold of five spatial candidates may be imposed. In addition to considering the spatial candidates illustrated in FIG. 2, additional candidates that may be considered for addition to the fusion list may include one temporal fusion candidate, which may be derived from two temporally co-located blocks, a combined bi-predictive candidate, and a zero motion vector candidate.

[0022] Still referring to FIG. 2, spatial fusion candidates may be added to the fusion list in response to determining that they are available. In quad-tree plus binary decision tree (QTBT) partitioning, some of the neighboring blocks may be asymmetric blocks and therefore may not be considered as spatial fusion candidates because they may be more likely to be partitioned asymmetrically since the partitions (e.g., prediction units) do not share similar motion information.

[0023] As described above, and with continued reference to FIG. 2, in some approaches to video coding, a fusion candidate list may be constructed based on the following candidates: up to four spatial fusion candidates derived from five spatial neighboring blocks, one temporal fusion candidate derived from two temporally co-located blocks, a combined bi-predictive candidate, and additional fusion candidates including a zero motion vector candidate.

[0024] Still referring to Figure 2, to derive the list of spatial candidates, there may be (a) a check whether neighboring blocks are available and contain motion information, and (b) a redundancy check to avoid having candidates with redundant motion data in the list.

[0025] Continuing with reference to FIG. 2, when N is the number of spatial fusion candidates, a full redundancy check may consist of N×(N−1) / 2 motion data comparisons. In the case of five potential fusion candidates, ten motion data comparisons may be used so that all candidates in the fusion list have different motion data. This may result in increased decoder complexity.

[0026] In some approaches to video coding, still referring to FIG. 2, in order to improve coding efficiency, after a fusion candidate list is constructed (the processing order of spatial candidate locations is A1, B1, B0, A0, B2), the order of each fusion candidate is adjusted according to the template matching cost. The template matching cost may be measured by the sum of absolute difference (SAD) between neighboring samples of the current coding unit (CU) and their corresponding reference samples. For example, but not limited to, the fusion candidates may be ordered in ascending order of the SAD calculated using the fusion candidates. The number of fusion candidates selected using the template matching cost may be limited. For example, a set of four lowest cost candidates among five first occurring and / or provided candidates may be selected.

[0027] Still referring to FIG. 2, some implementations of the present subject matter may further improve coding efficiency by reordering fusion candidates using global motion vectors. Global motion in a video as used in this disclosure refers to motion that occurs in an entire frame. Global motion may typically be caused by camera motion, such as camera panning and zooming, that affects the entire frame.

[0028] Still referring to FIG. 2, some implementations of the present subject matter may generate a fusion candidate list based on motion vectors signaled to a decoder. If global motion is signaled, such global motion may be expected to be common to many blocks in a frame. For example, as illustrated for illustrative purposes in FIG. 3, three of five spatial fusion candidates (B1, B2, and A1) may be signaled based on global motion. Based on the signaling step, at the decoder, the decoder may create a list of the following fusion candidates. They are ordered in such a way that the global motion candidate is the first one in the list as shown in Table 1. [Table 1]

[0029] Still referring to Figure 2, because blocks are more likely to have motion similar to the global motion, modifying the list so that the global motion vector is the first candidate in the list may signal prediction candidates and reduce the bits required to encode the motion vector difference. In such a way, motion vector coding may be improved and bit rate may be reduced, which would improve compression efficiency.

[0030] In some implementations, with continued reference to FIG. 2, signaling of global motion may be included in a header, such as a PPS or SPS. Global motion may vary between pictures. Motion vectors signaled in the picture header may describe motion relative to a previously decoded frame. In some implementations, global motion may be translational or affine. The motion mode used, such as the number of parameters, whether the model is affine, translational, or the like, may also be signaled in the picture header. FIG. 4 illustrates three example embodiments of motion models 600 that may be utilized for global motion, including their index values ​​(0, 1, or 2).

[0031] Still referring to Figure 4, translational CPMVs may be signaled in the PPS. Control points may be predefined. For example, control point MV 0 may be relative to the top left corner of the picture, MV 1 may be relative to the top right corner, and MV 3 may be relative to the bottom left corner of the picture.

[0032] Continuing with reference to Figure 4, the global motion may be relative to a previously coded frame. When only one set of global motion parameters is present, the motion can be relative to the frame presented immediately before the current frame.

[0033] FIG. 5 is a process flow diagram illustrating an exemplary embodiment of a process 500 for reordering fusion candidates based on global motion vectors.

[0034] At step 505, still referring to FIG. 5, a bitstream including a current block is received by the decoder. The current block may be contained within the bitstream received by the decoder. The bitstream may include data found in a stream of bits that is input to the decoder when using data compression, for example. The bitstream may include information necessary to decode the video. The receiving step may include extracting and / or parsing the block and associated signaling information from the bitstream. In some implementations, the current block may include a coding tree unit (CTU), a coding unit (CU), or a prediction unit (PU).

[0035] In step 510, still referring to FIG. 5, a motion vector candidate list may be constructed for the current block, including motion vector candidates having motion information that characterize a global motion vector. The global motion vector may be characterized by a bitstream header, which includes a picture parameter set (PPS) and / or a sequence parameter set (SPS).

[0036] 5, in step 515, the motion vector candidate list is sorted such that the motion vector candidate having motion information characterizing a global motion vector is the first one in the sorted motion vector candidate list. The sorting step may include inserting the first global motion vector candidate into the fusion candidate list. In some implementations, building the motion vector candidate list may include a sorting step.

[0037] At step 520, and still referring to FIG. 5, the pixel data for the current block may be reconstructed using the reordered motion vector candidate list.

[0038] Still referring to FIG. 5, in some implementations, the decoder may be configured to determine that a global motion is indicated for a current frame that includes the current block. The global motion vector may include a control point motion vector. The control point motion vector may include a translational motion vector. The control point motion vector may include a vector of a four-parameter affine motion model or a six-parameter affine motion model.

[0039] 6 is a system block diagram illustrating an example decoder 600 capable of decoding a bitstream using reordering of fusion candidates based on global motion vectors. The decoder 600 may include an entropy decoder processor 604, an inverse quantization and inverse transform processor 608, a deblocking filter 612, a frame buffer 616, a motion compensation processor 620, and / or an intra prediction processor 624.

[0040] In operation, still referring to FIG. 6, a bitstream 628 may be received by the decoder 600 and input to the entropy decoder processor 604, which may entropy decode a portion of the bitstream into quantized coefficients. The quantized coefficients may be provided to the inverse quantization and inverse transform processor 608, which may perform inverse quantization and inverse transform and generate a residual signal, which may be added to the output of the motion compensation processor 620 or the intra prediction processor 624, depending on the processing mode. The output of the motion compensation processor 620 and the intra prediction processor 624 may include a block prediction based on previously decoded blocks. The sum of the prediction and residual may be processed by the deblocking filter 612 and stored in the frame buffer 616.

[0041] 7 is a process flow diagram illustrating an example embodiment of a process 700 of encoding video using reordering of fusion candidates based on global motion vectors in accordance with some aspects of the present subject matter, which may improve compression efficiency while reducing encoding complexity. In step 705, the video frame may undergo initial block segmentation using, for example, a tree-structured macroblock partitioning scheme, which may include partitioning the picture frame into CTUs and CUs.

[0042] In step 710, a candidate list may be determined. The candidate list may be based on the global motion for the current block. The candidate list may include motion vector candidates having motion information characterizing a global motion vector. The motion vector candidate list may be sorted such that the motion vector candidate having motion information characterizing a global motion vector is the first one in the sorted motion vector candidate list. The sorting step may include inserting the first global motion vector candidate into the fused candidate list. In some implementations, building the motion vector candidate list may include a sorting step.

[0043] In step 715, the block may be encoded and included in the bitstream. The encoding may include, as a non-limiting example, utilizing inter-prediction and intra-prediction modes. More specifically, an index into the reordered candidate list may be included and / or encoded in the bitstream for use by the decoder.

[0044] FIG. 8 is a system block diagram illustrating an example video encoder 800 capable of encoding video using a reordering of fusion candidates based on global motion vectors. The example video encoder 800 may receive an input video 804, which may first be segmented or divided according to a processing scheme such as a tree-structured macroblock partitioning scheme (e.g., quadtree+binary tree). An example of a tree-structured macroblock partitioning scheme may include partitioning a picture frame into large block elements called coding tree units (CTUs). In some implementations, each CTU may be further partitioned one or more times into several sub-blocks, called coding units (CUs). The end result of this partitioning may include a group of sub-blocks, which may be called prediction units (PUs). Transform units (TUs) may also be utilized.

[0045] 8, an exemplary video encoder 800 may include an intra-prediction processor 808, a motion estimation / compensation processor 812, which may also be referred to as an inter-prediction processor, which is capable of building a motion vector candidate list, including adding global motion vector candidates to the motion vector candidate list, a transform / quantization processor 816, an inverse quantization / inverse transform processor 820, an in-loop filter 824, a decoded picture buffer 828, and / or an entropy coding processor 832. Bitstream parameters may be input to the entropy coding processor 832 for inclusion in an output bitstream 836.

[0046] In operation, and continuing to refer to Figure 8, for each block of a frame of the input video 804, it may be determined whether to process the block via intra-picture prediction or using motion estimation / compensation. The block may be provided to an intra-prediction processor 808 or a motion estimation / compensation processor 812. If the block is to be processed via intra-prediction, the intra-prediction processor 808 may perform the processing and output a predictor. If the block is to be processed via motion estimation / compensation, the motion estimation / compensation processor 812 may perform the processing, including building a motion vector candidate list, including adding global motion vector candidates to the motion vector candidate list, if applicable.

[0047] With further reference to FIG. 8, a residual may be formed by subtracting the predictor from the input video. The residual may be received by a transform / quantization processor 816, which may perform a transform process (e.g., a discrete cosine transform (DCT)) to produce coefficients, which may be quantized. The quantized coefficients and any associated signaling information may be provided to an entropy coding processor 832 for entropy encoding and inclusion in an output bitstream 836. The entropy encoding processor 832 may assist in encoding signaling information related to encoding the current block. In addition, the quantized coefficients may be combined with the predictor and provided to an inverse quantization / inverse transform processor 820, which may reconstruct pixels that may be processed by an in-loop filter 824, the output of which may be stored in a decoded picture buffer 828 for use by a motion estimation / compensation processor 812, which may build a motion vector candidate list, including adding global motion vector candidates to the motion vector candidate list.

[0048] Continuing with reference to Figure 8, several variations have been described in detail above, but other modifications or additions are possible. For example, in some implementations, the current block may include any symmetric block (8x8, 16x16, 32x32, 64x64, 128x128, and the like) and any asymmetric block (8x4, 16x8, and the like).

[0049] In some implementations, still referring to FIG. 8, a quad-tree plus binary decision tree (QTBT) may be implemented. In QTBT, at the coding tree unit level, the partition parameters of QTBT may be dynamically derived to fit local characteristics without transmitting any overhead. Then, at the coding unit level, a joint classifier decision tree structure may eliminate unnecessary iterations and control the risk of erroneous prediction. In some implementations, an LTR frame block update mode may be available as an additional option available per leaf node of QTBT.

[0050] In some implementations, still referring to Figure 8, additional syntax elements may be signaled at different hierarchical levels of the bitstream. For example, a flag may be enabled throughout a sequence by including an enabled flag coded in a sequence parameter set (SPS). Additionally, a CTU flag may be coded at the coding tree unit (CTU) level.

[0051] It should be noted that any one or more of the aspects and embodiments described herein may be conveniently implemented using digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), computer hardware, firmware, software, and / or combinations thereof, as realized and / or implemented in one or more machines (e.g., one or more computing devices utilized as user computing devices for electronic documents, one or more server devices, such as document servers, etc.) programmed according to the teachings herein, as would be apparent to one skilled in the computer arts. These various aspects or features may include implementation in one or more computer programs and / or software executable and / or interpretable on a programmable system including at least one programmable processor, which may be special purpose or general purpose, coupled to receive data and instructions from and transmit data and instructions to a storage system, at least one input device, and at least one output device. Appropriate software coding may be readily prepared by skilled programmers based on the teachings of the present disclosure, as would be apparent to one skilled in the software arts. The aspects and implementations discussed above that employ software and / or software modules may also include suitable hardware to assist in implementing the machine-executable instructions of the software and / or software modules.

[0052] Such software may be a computer program product employing a machine-readable storage medium. A machine-readable storage medium may be any medium capable of storing and / or encoding a sequence of instructions for execution by a machine (e.g., a computing device) and causing the machine to perform any one of the methodologies and / or embodiments described herein. Examples of machine-readable storage media include, but are not limited to, magnetic disks, optical disks (e.g., CDs, CD-Rs, DVDs, DVD-Rs, etc.), magneto-optical disks, read-only memory "ROM" devices, random access memory "RAM" devices, magnetic cards, optical cards, solid-state memory devices, EPROMs, EEPROMs, programmable logic devices (PLDs), and / or any combination thereof. Machine-readable media, as used herein, is intended to include a single medium as well as a collection of physically separate media, such as, for example, a collection of compact discs or one or more hard disk drives in combination with a computer memory. As used herein, machine-readable storage media does not include a transitory form of signal transmission.

[0053] Such software may also include information (e.g., data) carried as a data signal on a data carrier, such as a carrier wave. For example, machine-executable information may be included as a data carrying signal embodied in a data carrier, which signal encodes a sequence of instructions, or a portion thereof, for execution by a machine (e.g., a computing device), and any associated information (e.g., data structures and data) that causes the machine to perform any one of the methodologies and / or embodiments described herein.

[0054] Examples of computing devices include, but are not limited to, e-book reading devices, computer workstations, terminal computers, server computers, handheld devices (e.g., tablet computers, smart phones, etc.), web appliances, network routers, network switches, network bridges, any machine capable of executing a sequence of instructions that define actions to be taken by the machine, and any combination thereof. In one embodiment, the computing device may include and / or be included within a kiosk.

[0055] 9 illustrates a diagrammatic representation of one embodiment of a computing device in the exemplary form of a computer system 900 on which a set of instructions for causing a control system to perform any one or more of the aspects and / or methodologies of the present disclosure may be executed. It is also envisioned that multiple computing devices may be utilized to implement a specially configured set of instructions for causing one or more of the devices to perform any one or more of the aspects and / or methodologies of the present disclosure. The computer system 900 includes a processor 904 and a memory 908 that communicate with each other and with other components via a bus 912. The bus 912 may include any of several types of bus structures, including, but not limited to, a memory bus, a memory controller, a peripheral bus, a local bus, and any combination thereof, using any of a variety of bus architectures.

[0056] Memory 908 may include a variety of components (e.g., machine-readable media), including, but not limited to, random access memory components, read-only components, and any combination thereof. In one embodiment, a basic input / output system 916 (BIOS), including the basic routines that help to transfer information between elements within computer system 900, such as during start-up, may be stored in memory 908. Memory 908 may also include (e.g., stored on one or more machine-readable media) instructions (e.g., software) 920 that embody any one or more of the aspects and / or methodologies of the present disclosure. In another embodiment, memory 908 may further include any number of program modules, including, but not limited to, an operating system, one or more application programs, other program modules, program data, and any combination thereof.

[0057] Computer system 900 may also include a storage device 924. Examples of storage devices (e.g., storage device 924) include, but are not limited to, hard disk drives, magnetic disk drives, optical disk drives in combination with optical media, solid-state memory devices, and any combination thereof. Storage device 924 may be connected to bus 912 by an appropriate interface (not shown). Exemplary interfaces include, but are not limited to, SCSI, Advanced Technology Attachment (ATA), Serial ATA, Universal Serial Bus (USB), IEEE 1394 (FIREWIRE®), and any combination thereof. In one embodiment, storage device 924 (or one or more components thereof) may be removably interfaced with computer system 900 (e.g., via an external port connector (not shown)). In particular, storage device 924 and associated machine-readable media 928 may provide non-volatile and / or volatile storage of machine-readable instructions, data structures, program modules, and / or other data for computer system 900. In one embodiment, the software 920 may reside, completely or partially, within the machine-readable medium 928. In another embodiment, the software 920 may reside, completely or partially, within the processor 904.

[0058] Computer system 900 may also include input devices 932. In one embodiment, a user of computer system 900 may type commands and / or other information into computer system 900 via input devices 932. Examples of input devices 932 include, but are not limited to, alphanumeric input devices (e.g., keyboards), pointing devices, joysticks, gamepads, audio input devices (e.g., microphones, voice response systems, etc.), cursor control devices (e.g., mice), touchpads, optical scanners, video capture devices (e.g., still cameras, video cameras), touch screens, and any combination thereof. Input devices 932 may be interfaced to bus 912 via any of a variety of interfaces (not shown), including, but not limited to, a serial interface, a parallel interface, a game port, a USB interface, a FIREWIRE® interface, an interface directly to bus 912, and any combination thereof. Input devices 932 may include a touch screen interface, which may be part of or separate from display 936, discussed further below. The input device 932 may be utilized as a user selection device for selecting one or more graphical representations within a graphical interface such as those described above.

[0059] A user may also input commands and / or other information to computer system 900 via storage device 924 (e.g., a removable disk drive, flash drive, etc.) and / or network interface device 940. A network interface device, such as network interface device 940, may be utilized to connect computer system 900 to one or more of a variety of networks, such as network 944, and one or more remote devices 948 connected thereto. Examples of network interface devices include, but are not limited to, a network interface card (e.g., a mobile network interface card, a LAN card), a modem, and any combination thereof. Examples of networks include, but are not limited to, a wide area network (e.g., the Internet, an enterprise network), a local area network (e.g., a network associated with an office, a building, a campus, or other relatively small geographic space), a telephone network, a data network associated with a telephone / voice provider (e.g., a data and / or voice network of a mobile communications provider), a direct connection between two computing devices, and any combination thereof. A network, such as network 944, may employ wired and / or wireless modes of communication. In general, any network topology may be used. Information (eg, data, software 920 , etc.) may be communicated to and / or from computer system 900 via network interface device(s) 940 .

[0060] The computer system 900 may further include a video display adapter 952 for communicating images displayable on a display device, such as the display device 936. Examples of a display device include, but are not limited to, a liquid crystal display (LCD), a cathode ray tube (CRT), a plasma display, a light emitting diode (LED) display, and any combination thereof. The display adapter 952 and the display device 936 may be utilized in combination with the processor 904 to provide graphical representations of aspects of the disclosure. In addition to a display device, the computer system 900 may include one or more other peripheral output devices, including, but not limited to, audio speakers, a printer, and any combination thereof. Such peripheral output devices may be connected to the bus 912 via a peripheral interface 956. Examples of a peripheral interface include, but are not limited to, a serial port, a USB connection, a FIREWIRE® connection, a parallel connection, and any combination thereof.

[0061] The foregoing is a detailed description of exemplary embodiments of the present invention. Various modifications and additions may be made without departing from the spirit and scope of the present invention. Each feature of the various embodiments described above may be combined with features of other described embodiments as appropriate to provide a combination of features in a related new embodiment. Furthermore, while the foregoing describes several separate embodiments, what is described herein is merely illustrative of the application of the principles of the present invention. In addition, although certain methods herein may be illustrated and / or described as being performed in a specific order, the order may be highly variable among those skilled in the art to achieve the embodiments as disclosed herein. Thus, the present description is intended to be taken as an example only, and is not intended to otherwise limit the scope of the present invention.

[0062] In the above description and in the claims, phrases such as "at least one of" or "one or more of" may occur and be followed by a conjunctive enumeration of elements or features. The term "and / or" may also occur within a list of two or more elements or features. Unless otherwise implied or explicitly contradicted by the context in which such a phrase is used, this is intended to mean any of the elements or features listed individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases "at least one of A and B," "one or more of A and B," and "A and / or B" are intended to mean "A alone, B alone, or A and B together," respectively. A similar interpretation is also intended with respect to lists containing more than two items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, and / or C" are intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together." Additionally, use of the term "based on" above and in the claims is intended to mean "based at least on," such that unrecited features or elements are also permissible.

[0063] The subject matter described herein may be embodied in a system, an apparatus, a method, and / or an article, depending on the desired configuration. The implementations described in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the subject matter described. Although some variations have been described in detail above, other modifications or additions are possible. In particular, further features and / or variations may be provided in addition to those described herein. For example, the implementations described above may be directed to various combinations and subcombinations of the disclosed features and / or combinations and subcombinations of some further features disclosed above. In addition, the logic flow depicted in the accompanying figures and / or described herein does not necessarily require the particular order shown or sequential order to achieve the desired results. Other implementations may be within the scope of the following claims.

Claims

1. A video encoder comprising circuitry: The circuitry comprises: Receiving a video signal; generating an encoded bitstream including a coded picture, the coded picture including a first region having a first contiguous plurality of coded units and a second region having a second contiguous plurality of coded units, the bitstream being decodable by a decoder configured to receive the bitstream; The device is configured to: The decoder comprises: constructing, for each coding unit in the first region, a motion vector candidate list, each motion vector candidate list having a common motion vector, and an order of motion vector candidates in each motion vector candidate list is determined such that the common motion vector is first; decoding the first consecutive plurality of coded units using the common motion vector from the motion vector candidate list, whereby a picture region with common motion is reconstructed within the first region; determining from the bitstream an individually determined motion vector for each coding unit of the second region, wherein adjacent coding units in the second region have different individually determined motion vectors, each individually determined motion vector being one of a control point motion vector or a translational motion vector for affine motion; decoding the second consecutive plurality of coding units using the individually determined motion vectors, whereby local motion within the second region is reconstructed; and The encoder is further configured to:

2. The encoder of claim 1, wherein the decoder receiving the bitstream is configured to determine that global motion is indicated for the coded picture.

3. The encoder of claim 1, wherein the common motion vector includes a control point motion vector.

4. The encoder of claim 3, wherein the control point motion vector is a translational motion vector.

5. The encoder of claim 3, wherein the control point motion vector is a vector of a four-parameter affine motion model.

6. The encoder of claim 3, wherein the control point motion vector is a vector of a six-parameter affine motion model.

7. A decoder comprising: The circuitry comprises: receiving a bitstream including a coded picture, the coded picture including a first region with common motion having a first consecutive plurality of coding units and a second region with local motion having a second consecutive plurality of coding units and an intra-prediction coding unit; constructing, for each coding unit in the first region, a motion vector candidate list, each motion vector candidate list having a common motion vector, the motion vector candidate lists being ordered such that the common motion vector is first; decoding the first consecutive plurality of coded units using the common motion vector from the motion vector candidate list, whereby a picture region with common motion is reconstructed within the first region; determining from the bitstream an individually determined motion vector for each coding unit of the second consecutive plurality of coding units, wherein adjacent coding units in the second consecutive plurality of coding units have different individually determined motion vectors, each individually determined motion vector being one of a translational motion vector for translational motion or a control point motion vector for four-parameter or six-parameter affine motion; decoding the second consecutive plurality of coding units using the individually determined motion vectors, whereby local motion within the second region is reconstructed; and decoding the intra-predicted coding unit using predictions from previously decoded coding units in the picture; and A decoder configured to:

8. A video encoder, comprising: The circuitry comprises: Receiving a video signal; generating an encoded bitstream including a coded picture, the coded picture including a first region with common motion having a first consecutive plurality of coding units and a second region with local motion having a second consecutive plurality of coding units and an intra-prediction coding unit, the bitstream being encoded for decoding by a decoder configured to receive the encoded bitstream; The device is configured to: The decoder implements a decoding method, the decoding method comprising: constructing, for each coding unit in the first region, a motion vector candidate list, each motion vector candidate list having a common motion vector, the motion vector candidate lists being ordered such that the common motion vector is first; decoding the first consecutive plurality of coded units using the common motion vector from the motion vector candidate list, whereby a picture region with common motion is reconstructed within the first region; determining from the bitstream an individually determined motion vector for each coding unit of the second consecutive plurality of coding units, wherein adjacent coding units in the second consecutive plurality of coding units have different individually determined motion vectors, each individually determined motion vector being one of a translational motion vector for translational motion or a control point motion vector for four-parameter or six-parameter affine motion; decoding the second consecutive plurality of coding units using the individually determined motion vectors, whereby local motion within the second region is reconstructed; and decoding the intra-predicted coding unit using predictions from previously decoded coding units in the picture; and a video encoder.

9. A computer-readable recording medium storing an encoded bitstream decodable by a decoding method, the method comprising: receiving a bitstream including a coded picture, the coded picture including a first region having a first contiguous plurality of coded units and a second region having a second contiguous plurality of coded units; constructing, for each coding unit in the first region, a motion vector candidate list, each motion vector candidate list having a common motion vector, the motion vector candidate lists being ordered such that the common motion vector is first; decoding the first consecutive plurality of coded units using the common motion vector from the motion vector candidate list, whereby a picture region with common motion is reconstructed within the first region; determining from the bitstream an individually determined motion vector for each coding unit of the second region, wherein adjacent coding units in the second region have different individually determined motion vectors, each individually determined motion vector being one of a control point motion vector or a translational motion vector for four-parameter or six-parameter affine motion; decoding the second consecutive plurality of coding units using the individually determined motion vectors, whereby local motion within the second region is reconstructed; and A computer-readable recording medium comprising:

10. The computer-readable recording medium of claim 9, wherein the common motion vector includes a control point motion vector.

11. The computer-readable recording medium of claim 10, wherein the control point motion vector is a translational motion vector.

12. The computer-readable recording medium of claim 10, wherein the control point motion vector is a vector of a four-parameter affine motion model.

13. The computer-readable recording medium of claim 10, wherein the control point motion vector is a vector of a six-parameter affine motion model.

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