The method performed by an apparatus for encoding a current block, includes: generating a predicted block by predicting the current block; generating a residual block of the current block by subtracting the predicted block from the current block; partitioning the residual block into a plurality of subblocks having various sizes, and transforming each of the subblocks by using a transform unit of a size identical to each of the subblocks, to thereby generate transform blocks of the subblocks; quantizing the transform blocks; and encoding transform coefficients of each of the quantized transform blocks.

The method performed by an apparatus for encoding a current block, includes: generating a predicted block by predicting the current block; generating a residual block of the current block by subtracting the predicted block from the current block; partitioning the residual block into a plurality of subblocks having various sizes, and transforming each of the subblocks by using a transform unit of a size identical to each of the subblocks, to thereby generate transform blocks of the subblocks; quantizing the transform blocks; and encoding transform coefficients of each of the quantized transform blocks.

An encoding target region in an image can be partitioned into a plurality of prediction regions. Based on prediction information of a neighboring region neighboring a target region, the number of previously-encoded prediction regions in the target region, and previously-encoded prediction information of the target region, a candidate for motion information to be used in generation of a predicted signal of the target prediction region as a next prediction region is selected from previously-encoded motion information of regions neighboring the target prediction region. According to the number of candidates for motion information selected, merging block information to indicate generation of the predicted signal of the target prediction region using the selected candidate for motion information and motion information detected by prediction information estimation means, or either one of the merging block information or the motion information is encoded.

An encoding target region in an image can be partitioned into a plurality of prediction regions. Based on prediction information of a neighboring region neighboring a target region, the number of previously-encoded prediction regions in the target region, and previously-encoded prediction information of the target region, a candidate for motion information to be used in generation of a predicted signal of the target prediction region as a next prediction region is selected from previously-encoded motion information of regions neighboring the target prediction region. According to the number of candidates for motion information selected, merging block information to indicate generation of the predicted signal of the target prediction region using the selected candidate for motion information and motion information detected by prediction information estimation means, or either one of the merging block information or the motion information is encoded.

Methods for decoding of a video bitstream by a video decoding circuit are provided. In one implementation, a method receives coded data for a 2N×2N coding unit (CU) from the video bitstream, selects one or more first codewords according to whether asymmetric motion partition is disabled or enabled when a size of said 2N×2N CU is not equal to a smallest CU size, wherein none of the first codewords corresponds to INTER N×N partition, selects one or more second codewords when the size of said 2N×2N CU is equal to the smallest CU size, wherein none of the second codewords corresponds to the INTER N×N partition when N is 4, determines a CU structure for said 2N×2N CU from the video bitstream using said one or more first codewords or said one or more second codewords, and decodes the video bitstream using the CU structure.

Methods for decoding of a video bitstream by a video decoding circuit are provided. In one implementation, a method receives coded data for a 2N×2N coding unit (CU) from the video bitstream, selects one or more first codewords according to whether asymmetric motion partition is disabled or enabled when a size of said 2N×2N CU is not equal to a smallest CU size, wherein none of the first codewords corresponds to INTER N×N partition, selects one or more second codewords when the size of said 2N×2N CU is equal to the smallest CU size, wherein none of the second codewords corresponds to the INTER N×N partition when N is 4, determines a CU structure for said 2N×2N CU from the video bitstream using said one or more first codewords or said one or more second codewords, and decodes the video bitstream using the CU structure.

Syntax structures that indicate the completion of coded regions of pictures are described. For example, a syntax structure in an elementary bitstream indicates the completion of a coded region of a picture. The syntax structure can be a type of network abstraction layer unit, a type of supplemental enhancement information message or another syntax structure. For example, a media processing tool such as an encoder can detect completion of a coded region of a picture, then output, in a predefined order in an elementary bitstream, syntax structure(s) that contain the coded region as well as a different syntax structure that indicates the completion of the coded region. Another media processing tool such as a decoder can receive, in a predefined order in an elementary bitstream, syntax structure(s) that contain a coded region of a picture as well as a different syntax structure that indicates the completion of the coded region.

Syntax structures that indicate the completion of coded regions of pictures are described. For example, a syntax structure in an elementary bitstream indicates the completion of a coded region of a picture. The syntax structure can be a type of network abstraction layer unit, a type of supplemental enhancement information message or another syntax structure. For example, a media processing tool such as an encoder can detect completion of a coded region of a picture, then output, in a predefined order in an elementary bitstream, syntax structure(s) that contain the coded region as well as a different syntax structure that indicates the completion of the coded region. Another media processing tool such as a decoder can receive, in a predefined order in an elementary bitstream, syntax structure(s) that contain a coded region of a picture as well as a different syntax structure that indicates the completion of the coded region.

A picture prediction method includes receiving a bitstream, parsing the bitstream to obtain a prediction mode of a current block, when the prediction mode of the current block is a combined intra and inter prediction mode, selecting an execution manner of a triangular prediction unit mode according to a preset policy, determining motion information of the current block according to the execution manner of the triangular prediction unit mode, performing a motion compensation process based on the motion information, to obtain an inter prediction sample, obtaining an intra prediction sample according to the prediction mode of the current block, and combining the inter prediction sample and the intra prediction sample to obtain a prediction picture of the current block.

Various innovations in media encoding are presented herein. In particular, the innovations can reduce the computational complexity of encoding by selectively skipping certain evaluation stages during encoding. For example, based on analysis of decisions made earlier in encoding or based on analysis of media to be encoded, an encoder can selectively skip evaluation of certain coding tools (such as residual coding or rate-distortion-optimized quantization), skip evaluation of certain values for parameters or settings (such as candidate unit sizes or transform sizes, or candidate partition patterns for motion compensation), and/or skip evaluation of certain coding modes (such as frequency transform skip mode) that are not expected to improve rate-distortion performance during encoding.