摘要:
A method of video coding using palette coding mode for color video in a non-444 color format is disclosed. The non-444 video data can be converted to the 444 format so that the palette designed for the 444 format can be used for the non-444 video data. For the 4:2:0 color format, each chroma sample collocated with corresponding quad luma samples is padded with three chroma samples to form converted quad chroma samples. For the 4:2:0 color format, if a current pixel does not belong to the color palette, one or more escape values are signaled for the current pixel and the escape value associated with the chroma sample of the current pixel for each color component is not signaled for three of the quad chroma sample locations collocated with corresponding quad luma samples.
摘要:
A method and apparatus for video data processing for video in YUV422 or YUV 444 formats are disclosed. In one embodiment, for a 2N×2N luma coding unit (CU) in YUV422 format, the transform process partitions residue data corresponding to the 2N×2N luma CU and the N×2N chroma CU into square luma and chroma transform units (TUs). The residue data associated with the luma and the chroma CUs are generated by applying prediction process to the luma CU and the chroma CU. The transform process is independent of prediction block size or prediction mode associated with the prediction process. In another embodiment, the prediction process splits the CU into two prediction blocks. Transform process is applied on the chroma residue data corresponding to the chroma CU to form one or more chroma TUs, wherein the transform process is dependent on CU size and prediction block size, or CU size and prediction mode.
摘要:
An apparatus and method for video coding and decoding with constrained PU partition are disclosed. In the High Efficient Video Coding (HEVC) system, rate-distortion function or other performance criterion usually is evaluated for various CU partition and PU partition during the encoding process in order to select a configuration with best possible performance. The PU design in the current HEVC development results in some redundancy that causes rate-distortion function or other performance criterion repeatedly evaluated for same PU configuration. Accordingly, constrained PU partition is developed to eliminate or reduce the redundancy in processing. Furthermore, necessary syntax to convey the information related to constrained PU partition between an encoder and a decoder is developed. Systems embodying the present invention has been shown to result in sizeable reduction in encoding and decoding time while the performance in terms of RD-rate remains approximately the same or slightly higher than a conventional HEVC system.
摘要:
Embodiments according to the present invention configure the intra prediction mode candidates into multi-level MPM sets, which comprise at least a first-level MPM set and a second-level MPM set. Encoding or decoding a current intra prediction mode is based on the multi-level MPM sets, where one syntax element of the syntax information to be generated or decoded respectively is associated with evaluating the current intra prediction mode using the first-level MPM set. A method and apparatus for chroma intra prediction mode encoding and decoding are also disclosed. The chroma intra prediction mode set includes a Luma-based chroma prediction Mode (LM), a Direct Mode (DM) and four other modes. The codeword set comprises variable-length codewords and fixed-length codewords, and the fixed-length codewords are longer than the variable-length codewords. The variable-length codewords are used for the DM and LM, and the fixed-length codewords are used for the four other modes.
摘要:
A method and apparatus for Intra prediction of a block based on neighboring pixels around the block are disclosed. Embodiments according to the present invention use square blocks as well as non-square blocks for Intra prediction. For a 2N×2N Luma CU (coding unit), the CU can be partitioned into 2N×N, N×2N, 2N×2N or N×N PUs. The 2N×N and N×2N PUs can be further processed by either square transforms only or both non-square and square transforms. In one embodiment, the 2N×N PU or the N×2N PU is processed as two N×N TUs (transform units) and each of the N×N TU is further split into smaller N×N TUs based on quad-tree split. In another embodiment, the 2N×N and N×2N PUs are processed as two 2N×0.5N and 0.5N×2N TUs respectively.
摘要:
Embodiments according to the present invention configure the intra prediction mode candidates into multi-level MPM sets, which comprise at least a first-level MPM set and a second-level MPM set. Encoding or decoding a current intra prediction mode is based on the multi-level MPM sets, where one syntax element of the syntax information to be generated or decoded respectively is associated with evaluating the current intra prediction mode using the first-level MPM set. A method and apparatus for spectively is associated with evaluating the current intra prediction mode using the first-level MPM set. A method and apparatus for chroma intra prediction mode encoding and decoding are also disclosed. The chroma intra prediction mode set includes a Luma-based chroma prediction Mode (LM), a Direct Mode (DM) and four other modes. The codeword set comprises variable-length codewords and fixed-length codewords, and the fixed-length codewords are longer than the variable-length codewords. The variable-length codewords are used for the DM and LM, and the fixed-length codewords are used for the four other modes.
摘要:
In HEVC (High Efficiency Video Coding), a 2N×2N coding unit can be partitioned into various partition types hierarchically. The coding system uses a criterion to determine the best partition, where RD-rate is often used as the criterion. N×N partition at level k becomes redundant if 2N×2N at level k+1 will be evaluated. In order to eliminate the above redundancy, the allowable partition sizes are constrained according to a method previously disclosed. In the current invention, the complexity is further reduced. According to one embodiment, N×N partition is not allowed for any INTER mode regardless of the coding unit size. Furthermore, flexibility is provided so that either the method and apparatus with further complexity reduction can be selected or an alternative method and apparatus can be selected. Syntaxes to support embodiments according to the present invention are also disclosed.
摘要:
Three block concepts are introduced in HEVC: coding unit (CU), prediction unit (PU), and transform unit (TU). The overall coding structure is characterized by the various sizes of CU, PU and TU in a recursive fashion. For transform processing in current HEVC, a hierarchy RQT (Residual Quad Tree) is used and the TU size is related to the CU size, but independent of the PU size. This results in high encoding complexity and also causes increased processing time to process the syntax of residual quad tree. Accordingly a modified transform unit partition with reduced complexity is disclosed. According to an embodiment, the TU size may be restricted to the minimum of PU width and height, except for a 2N×2N coding unit with the 2N×2N partition type. In another embodiment, the maximum TU size equals to maximum of PU width and height, and the minimum TU size equals to minimum of the PU width and height, except for a 2N×2N coding unit with the 2N×2N partition type. In yet another embodiment, the TU size is selected between 2N×2N and N×N for the 2N×2N, 2N×N, N×2N and N×N partition types. The syntax element, split_transform_flag, is used to indicate the selection of 2N×2N or N×N TU size when needed. Furthermore, a method with reduced complexity of selecting the best merge candidate for the 2N×2N CU merge mode is disclosed. The method relies on R-D cost associated with the motion vector of merge candidate to reduce required computation.
摘要:
A method and apparatus of Intra mode coding for a scalable video coding system are disclosed. For a current Intra-coded block in the enhancement layer (EL), predictive coding is applied to the current Intra mode based on the base layer (BL) coding mode associated with the co-located block in the BL and neighboring coding modes associated with neighboring blocks of the current block in the EL. The neighboring blocks of the current block in the EL comprise a left block adjacent to a left side of the current block and a top block adjacent to a top side of the current block. One or more most probable modes (MPMs) can be derived from the neighboring coding modes and the BL coding mode, and the MPMs is then used for predictive coding of the current Intra mode.
摘要:
A method and apparatus of Intra mode coding for a scalable video coding system are disclosed. For a current Intra-coded block in the enhancement layer (EL), predictive coding is applied to the current Intra mode based on the base layer (BL) coding mode associated with the co-located block in the BL and neighboring coding modes associated with neighboring blocks of the current block in the EL. The neighboring blocks of the current block in the EL comprise a left block adjacent to a left side of the current block and a top block adjacent to a top side of the current block. One or more most probable modes (MPMs) can be derived from the neighboring coding modes and the BL coding mode, and the MPMs is then used for predictive coding of the current Intra mode.