Adaptive motion vector prediction candidates in frame with global motion

Abstract

To provide an adaptive motion vector prediction candidate in a frame with global motion.SOLUTION: A decoder includes a circuit network that receives the bitstream, determines a global motion vector candidate utilized by a neighboring block by using the bitstream for the current block, adds the determined global motion vector candidate to a motion vector candidate list, builds the motion vector candidate list, reconstructs pixel data for the current block, and use the motion vector candidate list. There are also provided a related device, system, technique, and article.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 838,615, filed April 25, 2019, and entitled “ADAPTIVE MOTION VECTOR PREDICTION CANDIDATES IN FRAMES WITH GLOBAL MOTION,” which is incorporated by reference in its entirety.

[0002] The present invention relates generally to the field of video compression, and more particularly to adaptive motion vector prediction candidates in frames with global motion. [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., as 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 past 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 past in time compared to the current picture and from the future 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, the decoder includes circuitry configured to receive a bitstream, determine, for a current block, global motion vector candidates utilized by neighboring blocks using the bitstream, build a motion vector candidate list including adding the determined global motion vector candidates to the motion vector candidate list, and reconstruct pixel data for the current block and use the motion vector candidate list.

[0008] In another aspect, the method includes receiving, by a decoder, a bitstream; determining, for a current block, global motion vector candidates to be utilized by neighboring blocks using the bitstream; constructing a motion vector candidate list, the constructing of the motion vector candidate list further including adding the determined global motion vector candidates to the motion vector candidate list; and reconstructing pixel data of the current block and using the 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 specification also provides, for example, the following items: (Item 1) 1. A decoder, comprising: A circuitry comprising: receiving a bitstream; determining, for a current block, candidate global motion vectors utilized by neighboring blocks using the bitstream; constructing a motion vector candidate list, including adding the determined global motion vector candidate to a motion vector candidate list; reconstructing pixel data for the current block and using the motion vector candidate list; A circuit network configured to: A decoder comprising: (Item 2) 2. The decoder of claim 1, wherein the global motion vector candidates include a predefined global motion model type. (Item 3) 2. The decoder of claim 1, wherein the global motion vector candidates include control point motion vectors. (Item 4) 4. The decoder of claim 3, wherein the control point motion vector is a translational motion vector. (Item 5) 4. The decoder according to item 3, wherein the control point motion vectors are vectors of a four-parameter affine motion model. (Item 6) 4. The decoder of claim 3, wherein the control point motion vectors are vectors of a six-parameter affine motion model. (Item 7) an entropy decoder processor configured to receive the bitstream and decode the bitstream into quantized coefficients; an inverse quantization and inverse transform processor configured to process the quantized coefficients, including performing inverse discrete cosine; and A deblocking filter; A frame buffer; Intra prediction processor Item 1. The decoder of item 1, further comprising: (Item 8) 2. The decoder of claim 1, wherein the current block forms part of a quadtree+binary decision tree. (Item 9) 2. The decoder of claim 1, wherein the current block is a coding tree unit. (Item 10) 2. The decoder of claim 1, wherein the current block is a coding unit. (Item 11) 2. The decoder of claim 1, wherein the current block is a prediction unit. (Item 12) 2. The decoder of claim 1, wherein the global motion model of the candidate global motion vectors includes translational motion. (Item 13) 2. The decoder of claim 1, wherein the global motion model of the candidate global motion vectors comprises affine motion. (Item 14) 10. The decoder of claim 9, wherein the global motion model is characterized by a header of the bitstream, the header including a picture parameter set. (Item 15) 10. The decoder of claim 9, wherein the global motion model is characterized by a header of the bitstream, the header including a sequence parameter set. (Item 16) 1. A method comprising: receiving, by a decoder, a bitstream; determining, for a current block, candidate global motion vectors utilized by neighboring blocks using the bitstream; constructing a motion vector candidate list, the constructing of the motion vector candidate list further comprising adding the determined global motion vector candidate to the motion vector candidate list; reconstructing pixel data for the current block and using the motion vector candidate list; A method comprising: (Item 17) Item 17. The method of item 16, wherein the global motion vector candidates include a predefined global motion model type. (Item 18) Item 17. The method of item 16, wherein the global motion vector candidates 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 according to 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 further comprises: an entropy decoder processor configured to receive the bitstream and decode the bitstream into quantized coefficients; an inverse quantization and inverse transform processor configured to process the quantized coefficients, including performing inverse discrete cosine; and A deblocking filter; A frame buffer; Intra prediction processor Item 17. The method of item 16, comprising: (Item 23) 17. The method of claim 16, wherein the current block forms part of a quadtree+binary decision tree. (Item 24) Item 17. The method of item 16, wherein the current block is a coding tree unit. (Item 25) Item 17. The method of item 16, wherein the current block is a coding unit. (Item 26) Item 17. The method of item 16, wherein the current block is a prediction unit. (Item 27) 17. The method of claim 16, wherein the global motion model of the candidate global motion vectors includes translational motion. (Item 28) 17. The method of claim 16, wherein the global motion model of the candidate global motion vectors includes affine motion. (Item 29) 29. The method of claim 28, wherein the global motion model is characterized by a header of the bitstream, the header including a picture parameter set. (Item 30) 29. The method of claim 28, wherein the global motion model is characterized by a header of the bitstream, the header including a sequence parameter set. [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.

[0012] [Diagram 2] FIG. 2 illustrates three example motion models that may be utilized for global motion, including their index values ​​(0, 1, or 2).

[0013] [Diagram 3] FIG. 3 is a process flow diagram according to some example implementations of the present subject matter.

[0014] [Figure 4] FIG. 4 is a system block diagram of an example decoder in accordance with some example implementations of the present subject matter.

[0015] [Diagram 5] FIG. 5 is a process flow diagram according to some example implementations of the present subject matter.

[0016] [Figure 6] FIG. 6 is a system block diagram of an example encoder in accordance with some example implementations of the present subject matter.

[0017] [Figure 7] FIG. 7 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.

[0018] 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

[0019] Global motion in video refers to motion that occurs in the entire frame. Global motion may be caused by camera motion, e.g., camera panning and zooming creates motion in a frame that may typically affect the entire frame. Motion that is present within a portion of a video may be referred to as local motion. Local motion may be caused by moving objects in a scene, such as, but not limited to, an object moving from left to right in a scene. Video may contain a combination of local and global motion. Some implementations of the present subject matter may provide an efficient approach for communicating global motion to a decoder and the use of global motion vectors in improving compression efficiency.

[0020] FIG. 1 is a diagram illustrating motion vectors of an example frame 100 with global and local motion. Frame 100 may include 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) indicate blocks with local motion. In the illustrated example of FIG. 1, many blocks have the same global motion. Signaling global motion in a header, such as a picture parameter set (PPS) and / or a sequence parameter set (SPS), and using the signaled global motion may reduce the motion vector information required by blocks and may result in improved prediction. For illustrative purposes, the embodiments described below refer to determining and / or applying global or local motion vectors at the block level, although global motion vectors may be determined and / or applied with respect to any region of a frame and / or picture (including, but not limited to, a region comprised of multiple blocks, a region bounded by any geometric form, such as, but not limited to, a region defined by geometric and / or exponential coding, in which one or more lines and / or curves bounding a shape may be angled and / or curved, and / or the entire frame and / or picture). Although signaling is described herein as being performed at the frame level and / or within the header and / or frame parameter set, signaling may alternatively or additionally be performed at a sub-picture level, where a sub-picture may include any region of a frame and / or picture as described above.

[0021] 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 the uniform displacement of a set of pixels or points, such as a video picture and / or a set of pixels that illustrate an object represented within a picture that moves 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.

[0022] For example, with continued reference to FIG. 1, a six-parameter affine motion can be described as follows: x'=ax+by+c y'=dx+ey+f As a further example, a 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 parameters of the affine motion model.

[0023] Still referring to FIG. 1, the parameters used to describe the 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 the affine motion parameters using the control point motion vectors may enable the use of efficient motion vector coding methods to signal the affine motion parameters.

[0024] In an embodiment, with continued reference to FIG. 1, sps_affine_enabled_flag in the PPS and / or SPS may specify whether affine model-based motion compensation may be used for inter prediction. If sps_affine_enabled_flag is equal to 0, the syntax may be constrained such that affine model-based motion compensation is not used in a coded video sequence (CLVS), and inter_affine_flag and cu_affine_type_flag may not be present in the coding unit syntax of the CLVS. Otherwise (sps_affine_enabled_flag is equal to 1), affine model-based motion compensation may be used in the CLVS.

[0025] With further reference to FIG. 1 , sps_affine_type_flag in the PPS and / or SPS may specify whether 6-parameter affine model-based motion compensation may be used for inter prediction. If sps_affine_type_flag is equal to 0, the syntax may be constrained such that 6-parameter affine model-based motion compensation is not used in the CLVS, and cu_affine_type_flag may not be present in the coding unit syntax of the CLVS. Otherwise (sps_affine_type_flag is equal to 1), 6-parameter affine model-based motion compensation may be used in the CLVS. When not present, the value of sps_affine_type_flag may be inferred to be equal to 0.

[0026] Continuing with reference to FIG. 1, the step of handling a list of MV prediction candidates may be a step implemented in some compression approaches that utilize motion compensation at the decoder. Some previous approaches may define the use of spatial and temporal motion vector candidates. Global motion signaled in a header such as SPS or PPS may indicate the presence of global motion in the video. Such global motion may be expected to be common to most blocks in a frame. By using global motion as a prediction candidate, motion vector coding may be improved and bitrate may be reduced. Candidate MVs added to the MV prediction list may be selected depending on the motion model used to represent global motion and / or the motion model used in intercoding.

[0027] Still referring to FIG. 1, some implementations of global motion may be described with one or more control point motion vectors (CPMVs), depending on the motion model used. Thus, depending on the motion model used, one to three control point motion vectors may be available and used as candidates for prediction. In some implementations, all available CPMVs may be added to a list as prediction candidates. The general case of adding all available CPMVs may increase the likelihood of finding a good motion vector prediction and improve compression efficiency. Table 1: [Table 1]

[0028] With continued reference to FIG. 1, working with a list of motion vector (MV) prediction candidates may be a step in implementing motion compensation in a decoder.

[0029] Still referring to FIG. 1, the global motion signaled in a header such as SPS may indicate the presence of global motion in the video. Such global motion may be likely to be present in many blocks in a frame. Thus, a given block may be likely to have motion similar to the global motion. By using the global motion as a prediction candidate, motion vector coding may be improved and bitrate may be reduced. Candidate MVs may be added to the MV prediction list, and the candidate MVs may be selected depending on the motion model used to represent the global motion and the motion model used in intercoding.

[0030] Continuing with reference to FIG. 1, global motion may be described using one or more control point motion vectors (CPMVs), depending on the motion model used. Thus, depending on the motion model used, one to three control point motion vectors may be available and used as candidates for prediction. The list of MV prediction candidates may be reduced by selectively adding one CPMV to the prediction candidate list. Reducing the list size may reduce computational complexity and improve compression efficiency. In some implementations, still referring to FIG. 1, the selection of CPMVs as candidates may follow a predefined mapping, such as that illustrated in Table 3 below. [Table 2]

[0031] Still referring to FIG. 1, the use of selective prediction candidates from global motion may be signaled within a picture parameter set of a sequence parameter set, thereby reducing encoding and decoding complexity.

[0032] Further referring to FIG. 1, because a block is more likely to have motion similar to the global motion, adding the global motion vector as the first candidate in the prediction list may signal the prediction candidate to be used and reduce the bits required to encode the motion vector difference.

[0033] With continued reference to FIG. 1, working with a list of motion vector (MV) prediction candidates may be a step in implementing motion compensation in a decoder.

[0034] Still referring to FIG. 1, global motion signaled in a header such as SPS may indicate the presence of global motion in a video. Such global motion is likely to be present in many blocks in a frame. Thus, a given block is likely to have motion similar to the global motion. By using the global motion as a prediction candidate, motion vector coding may be improved and bitrates may be reduced.

[0035] Further referring to FIG. 1, for example, a candidate MV to be added to the MV prediction list may be adaptively selected depending on which control point motion vector (CPMV) is selected as a prediction candidate in a neighboring block (e.g., a prediction unit (PU)).

[0036] As a further example, still referring to FIG. 1, if a neighboring PU uses a specific CPMV as a predicted MV for a specific control point, the CPMV may be added to the MV candidate list. If a neighboring PU uses more than one CPMV as a predicted MV (e.g., the left PU uses CPMV0 and the top PU uses CPMV1), all CPMVs used as prediction candidates may be added to the list. If a neighboring PU does not use a CPMV, the CPMV may not be added to the prediction list. In some implementations, global motion information may be added as the first candidate in the prediction list.

[0037] With continued reference to FIG. 1, the use of adaptive prediction candidates from global motion may be signaled within a header such as the PPS and / or SPS, thereby reducing encoding and decoding complexity.

[0038] Still referring to Figure 1, since blocks are more likely to have motion similar to the global motion, adding the global motion vector as the first candidate in the prediction list may signal the prediction candidate to be used and reduce the bits required to encode the motion vector difference. Figure 2 illustrates three example motion models 200 that may be utilized for global motion, including their index values ​​(0, 1, or 2).

[0039] Still referring to Figure 2, the PPS may be used to signal parameters that may vary between pictures of a sequence. Parameters that remain the same for a sequence of pictures may be signaled in a sequence parameter set, reducing the size of the PPS and reducing the video bit rate. An exemplary picture parameter set (PPS) is shown in Table 2. [Table 3-1] [Table 3-2] [Table 3-3] [Table 3-4] [Table 3-5]

[0040] Additional fields may be added to the PPS to signal global motion. In case of global motion, the presence of global motion parameters in a sequence of pictures may be signaled in the SPS, and the PPS may reference the SPS by an SPS ID. The SPS may be modified to add a field to signal the presence of global motion parameters in the SPS in some approaches to decoding. For example, a 1-bit field may be added to the SPS. If the global_motion_present bit is 1, global motion related parameters may be expected to be in the PPS. If the global_motion_present bit is 0, global motion parameter related fields may not be present in the PPS. For example, the PPS of Table 2 may be extended to include a global_motion_present field, e.g., as shown in Table 3. [Table 4]

[0041] Similarly, the PPS may include a pps_global_motion_parameters field for the frame, eg, as shown in Table 4. [Table 5]

[0042] More specifically, the PPS may include fields for characterizing global motion parameters, for example using control point motion vectors as shown in Table 5. [Table 6-1] [Table 6-2]

[0043] As a further non-limiting example, Table 6 below may represent an exemplary SPS. [Table 7-1] [Table 7-2] [Table 7-3] [Table 7-4] [Table 7-5] [Table 7-6] [Table 7-7] [Table 7-8] [Table 7-9]

[0044] An SPS table such as the one above may be extended as described above to incorporate a global motion presence indicator such as that shown in Table 7. [Table 8]

[0045] Additional fields may be incorporated within the SPS to reflect further indicators as described within this disclosure.

[0046] In an embodiment, still referring to FIG. 2, sps_affine_enabled_flag in the PPS and / or SPS may specify whether affine model-based motion compensation may be used for inter prediction. If sps_affine_enabled_flag is equal to 0, the syntax may be constrained such that affine model-based motion compensation is not used in a coded video sequence (CLVS), and inter_affine_flag and cu_affine_type_flag may not be present in the coding unit syntax of the CLVS. Otherwise (sps_affine_enabled_flag is equal to 1), affine model-based motion compensation may be used in the CLVS.

[0047] Continuing with reference to FIG. 2, sps_affine_type_flag in the PPS and / or SPS may specify whether 6-parameter affine model-based motion compensation may be used for inter prediction. If sps_affine_type_flag is equal to 0, the syntax may be constrained such that 6-parameter affine model-based motion compensation is not used in the CLVS, and cu_affine_type_flag may not be present in the coding unit syntax of the CLVS. Otherwise (sps_affine_type_flag is equal to 1), 6-parameter affine model-based motion compensation may be used in the CLVS. When not present, the value of sps_affine_type_flag may be inferred to be equal to 0.

[0048] Still referring to FIG. 2, translational CPMV may be signaled within 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. Table 5 illustrates an example approach for signaling CPMV data depending on the motion model used.

[0049] In an example embodiment, still referring to FIG. 2, an array amvr_precision_idx, which may be signaled within a coding unit, coding tree, or equivalent, may specify a resolution of motion vector differences AmvrShift, which may be defined as a non-limiting example as shown in Table 8 as shown below. The array indexes x0, y0 may specify the location (x0, y0) of the top-left luma sample of the considered coding block relative to the top-left luma sample of the picture, and when amvr_precision_idx[x0][y0] is not present, it may be inferred to be equal to 0. When inter_affine_flag[x0][y0] is equal to 0, the variables MvdL0[x0][y0][0], MvdL0[x0][y0][1], MvdL1[x0][y0][0], MvdL1[x0][y0][1], which represent the motion vector difference values ​​corresponding to the considered block, may be, for example, [ka] If inter_affine_flag[x0][y0] is equal to 1, then the variables MvdCpL0[x0][y0][0][0], MvdCpL0[x0][y0][0][1], MvdCpL0[x0][y0][1][0], MvdCpL0[x0][y0][1][1], MvdCpL0[x0][y0][2][0], and MvdCpL0[x0][y0][2][1] may be modified, for example, to the following, i.e. [ka] [ka] The shifting step may be modified as follows: [Table 9]

[0050] FIG. 3 is a process flow diagram illustrating an example process 300 for building a motion vector candidate list using global motion vector candidates utilized by neighboring blocks.

[0051] At step 305, still referring to FIG. 3, a current block is received by the decoder. The current block may be contained within a bitstream that the decoder receives. The bitstream may include data found in a stream of bits that is input to the decoder, for example, when using data compression. 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).

[0052] In step 310, and still referring to Figure 3, global motion vector candidates utilized by neighboring blocks may be determined for the current block using the bitstream. In step 330, a motion vector candidate list may be constructed, including adding the determined global motion vector candidates to the motion vector candidate list. In step 140, pixel data of the current block may be reconstructed using the motion vector candidate list.

[0053] 4 is a system block diagram illustrating an example decoder 400 capable of decoding a bitstream, including building a motion vector candidate list using global motion vector candidates utilized by neighboring blocks. The decoder 400 may include an entropy decoder processor 404, an inverse quantization and inverse transform processor 408, a deblocking filter 412, a frame buffer 416, a motion compensation processor 420, and / or an intra prediction processor 424.

[0054] In operation, still referring to FIG. 4, a bitstream 428 may be received by the decoder 400 and input to the entropy decoder processor 404, 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 408, 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 420 or the intra prediction processor 424, depending on the processing mode. The output of the motion compensation processor 420 and the intra prediction processor 424 may include block predictions based on previously decoded blocks. The sum of the predictions and residuals may be processed by the deblocking filter 412 and stored in the frame buffer 416.

[0055] FIG. 5 is a process flow diagram illustrating an example embodiment of a process 500 for encoding video, including building a motion vector candidate list using global motion vector candidates utilized by neighboring blocks according to some aspects of the present subject matter, which may improve compression efficiency while reducing the complexity of the encoding step. In step 505, a video frame may undergo initial block segmentation, for example, by using a tree-structured macroblock partitioning scheme, which may include, but is not limited to, partitioning a picture frame into CTUs and CUs. In step 510, a global motion may be determined for a block. In step 515, the block may be encoded and included in a bitstream. The encoding may include building a motion vector candidate list using global motion vector candidates utilized by neighboring blocks. The encoding may include, for example, utilizing inter-prediction and intra-prediction modes.

[0056] FIG. 6 is a system block diagram illustrating an example video encoder 00 that is capable of constructing a motion vector candidate list using global motion vector candidates utilized by neighboring blocks. The example video encoder 600 may receive an input video 604, 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.

[0057] 6, an exemplary video encoder 600 may include an intra-prediction processor 608, a motion estimation / compensation processor 612, 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 616, an inverse quantization / inverse transform processor 620, an in-loop filter 624, a decoded picture buffer 628, and / or an entropy coding processor 632. Bitstream parameters may be input to the entropy coding processor 632 for inclusion in an output bitstream 636.

[0058] In operation, and continuing to refer to FIG. 6, for each block of a frame of the input video 604, it may be determined whether to process the block via intra-picture prediction or using motion estimation / compensation. The block may be provided to the intra-prediction processor 608 or the motion estimation / compensation processor 612. If the block is to be processed via intra-prediction, the intra-prediction processor 608 may perform processing and output a predictor. If the block is to be processed via motion estimation / compensation, the motion estimation / compensation processor 612 may perform processing including building a motion vector candidate list, including adding global motion vector candidates to the motion vector candidate list, if applicable.

[0059] With further reference to FIG. 6, a residual may be formed by subtracting the predictor from the input video. The residual may be received by a transform / quantization processor 616, 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 632 for entropy encoding and inclusion in an output bitstream 636. The entropy encoding processor 632 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 620, which may reconstruct pixels that may be processed by an in-loop filter 624, the output of which may be stored in a decoded picture buffer 628 for use by a motion estimation / compensation processor 612, which may build a motion vector candidate list, including adding global motion vector candidates to the motion vector candidate list.

[0060] Continuing with reference to Figure 6, 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).

[0061] In some implementations, still referring to FIG. 6, 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.

[0062] In some implementations, still referring to Figure 6, 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 7 shows a diagrammatic representation of one embodiment of a computing device in the exemplary form of a computer system 700 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 700 includes a processor 704 and a memory 708 that communicate with each other and with other components via a bus 712. The bus 712 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.

[0068] Memory 708 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 716 (BIOS), including the basic routines that help to transfer information between elements within computer system 700, such as during start-up, may be stored in memory 708. Memory 708 may also include (e.g., stored on one or more machine-readable media) instructions (e.g., software) 720 that embody any one or more of the aspects and / or methodologies of the present disclosure. In another embodiment, memory 708 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.

[0069] Computer system 700 may also include a storage device 724. Examples of storage devices (e.g., storage device 724) 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 724 may be connected to bus 712 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 724 (or one or more components thereof) may be removably interfaced with computer system 700 (e.g., via an external port connector (not shown)). In particular, storage device 724 and associated machine-readable media 728 may provide non-volatile and / or volatile storage of machine-readable instructions, data structures, program modules, and / or other data for computer system 700. In one embodiment, the software 720 may reside, completely or partially, within the machine-readable medium 728. In another embodiment, the software 720 may reside, completely or partially, within the processor 704.

[0070] Computer system 700 may also include input devices 732. In one embodiment, a user of computer system 700 may type commands and / or other information into computer system 700 via input devices 732. Examples of input devices 732 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 732 may be interfaced to bus 712 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 712, and any combination thereof. Input devices 732 may include a touch screen interface, which may be part of or separate from display 736, discussed further below. The input device 732 may be utilized as a user selection device for selecting one or more graphical representations within a graphical interface such as those described above.

[0071] A user may also input commands and / or other information to computer system 700 via storage device 724 (e.g., a removable disk drive, flash drive, etc.) and / or network interface device 740. A network interface device, such as network interface device 740, may be utilized to connect computer system 700 to one or more of a variety of networks, such as network 744, and one or more remote devices 748 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, a corporate 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 744, may employ wired and / or wireless modes of communication. In general, any network topology may be used. Information (eg, data, software 720 , etc.) may be communicated to and / or from computer system 700 via network interface device 740 .

[0072] Computer system 700 may further include a video display adapter 752 for communicating images displayable on a display device, such as display device 736. Examples of display devices 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. Display adapter 752 and display device 736 may be utilized in combination with processor 704 to provide graphical representations of aspects of the disclosure. In addition to a display device, computer system 700 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 bus 712 via a peripheral interface 756. Examples of peripheral interfaces include, but are not limited to, a serial port, a USB connection, a FIREWIRE® connection, a parallel connection, and any combination thereof.

[0073] 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.

[0074] 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 expressly 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.

[0075] 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. 1. A computer-readable storage medium storing an encoded bitstream that is decodable by a decoder, the decoder comprising: receiving a bitstream including a coded picture, the coded picture including a first region comprising a first consecutive plurality of coding units and having global motion, and a second region comprising a second consecutive plurality of coding units and having local motion different from the global motion, the first consecutive plurality of coding units all having the same affine motion model; constructing, for each of the coding units in the first contiguous plurality of coding units, a motion vector candidate list, each motion vector candidate list comprising one or more motion vector candidates generated using motion vector information of adjacent coding units; reconstructing pixel data for each of the first consecutive coding units of the first region using a selected one of the motion vector candidates from a motion vector candidate list for the coding unit, the selected motion vector candidate being a candidate generated using motion vector information of neighboring coding units, the affine motion model being a six-parameter affine motion model that can be characterized by parameters a, b, c, d, e, and f, where: x'=ax+by+c y'=dx+ey+f where (x,y) is a pixel location in the first region of the coded picture and (x',y') is a pixel location in a reference picture, each selected motion vector candidate comprises three control point motion vectors, the selected motion vector candidates are used to derive affine motion parameters such that a, b, c, d, e, and f have substantially identical values ​​in all coding units of the first consecutive plurality of coding units of the first region, thereby reconstructing the global motion within the first region; reconstructing pixel data of the coding units in the second consecutive plurality of coding units, whereby the local motion is reconstructed; and A computer-readable storage medium configured to perform the steps of:

2. 1. A computer-readable storage medium storing an encoded bitstream that is decodable by a decoder, the decoder comprising: receiving a bitstream including a coded picture, the coded picture including a first region comprising a first consecutive plurality of coding units and having global motion, and a second region comprising a second consecutive plurality of coding units and having local motion different from the global motion, the first consecutive plurality of coding units all having the same affine motion model; constructing, for each of the coding units in the first contiguous plurality of coding units, a motion vector candidate list, each motion vector candidate list comprising one or more motion vector candidates generated using motion vector information of neighboring coding units; Decoding each of the first consecutive coding units of the first region using a selected one of the motion vector candidates from a motion vector candidate list of the coding unit, the selected motion vector candidate being a candidate generated using motion vector information of neighboring coding units, the affine motion model being a four-parameter affine motion model that can be characterized by parameters a, b, c, and f, where: x'=ax+by+c y'=-bx+ay+f where (x,y) is a pixel location in the first region of the coded picture and (x',y') is a pixel location in a reference picture, each selected motion vector candidate comprises two control point motion vectors, and the selected motion vector candidates are used to derive affine motion parameters such that a, b, c, and f have substantially identical values ​​in all coding units of the first consecutive plurality of coding units of the first region, thereby reconstructing the global motion within the first region; decoding the coding units in the second consecutive plurality of coding units whereby the local motion is reconstructed; and A computer-readable storage medium configured to perform the steps of:

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