Abstract:
Methods and apparatus for video coding using ringing smoothing filter (RSF) are disclosed. According to one method, ringing smoothing filter (RSF) is applied to the reconstructed residuals to form smoothed reconstructed residuals or applied to an in-loop-filtered reconstructed block to form a smoothed-filtered reconstructed block for the current block, where the RSF corresponds to an edge-preserving filter. The ringing smoothing filter (RSF) may correspond to a bilateral filter. According to another method, adaptive RSF is derived based on information comprising Intra prediction mode or Inter prediction mode. In yet another method, whether to apply ringing smoothing filter (RSF) to a current block in the current image is determined based on one or more control flags. If the control flag(s) indicates the RSF being on for the current block, the RSF is applied to the current block.
Abstract:
Processing methods and apparatuses for video data comprise receiving input data associated with a current coding block (CB) in a current slice, deriving a top-left location of a current quantization group containing the current CB using a recursive process or a tracking process, and determining a reference quantization parameter (QP) according to the top-left location of the current quantization group. The current CB is encoded or decoded according to the reference QP. The reference QP may be further derived based on a previous QP determined by a tracking method.
Abstract:
A method and apparatus of entropy coding for a video encoder or decoder using multiple-table based Context-Based Adaptive Binary Arithmetic Coder (CABAC) are disclosed. In one embodiment, a current bin of a binary data of a current coding symbol is encoded or decoded according to a probability of a binary value of the current bin and the probability of the binary value is updated according to the binary value of the current bin for a next bin by using multiple-parameter probability models. Each multiple-parameter probability model is updated using at least one lookup table with the individual set of probability state as a table index to access contents of said at least one lookup table. In another embodiment, the range update is calculated for a range interval based on middle value of the range interval.
Abstract:
A method and apparatus for video encoding and decoding with affine motion compensation are disclosed. An embodiment of the method receives input data associated with a current block coded or to be coded in an affine mode. Two or more motion vectors of a neighboring block are retrieved from a buffer, where at least one of the retrieved motion vectors is not corresponding to a sub-block in a first neighboring block row or a first neighboring block column. The method derives an affine candidate including affine motion vectors using the retrieved two or more motion vectors, and encodes or decodes the current block by predicting the current block using one or more motion compensated blocks by the derived affine candidate. The buffer for affine candidate derivation stores selective motion vectors less than all motion vectors of coded blocks in the current picture.
Abstract:
A video data processing method comprises receiving input data associated with a current picture, determining a size for a current coding tree unit (CTU) or a current coding unit (CU) in the current CTU, and if the size, a width, or a height of the current CTU or CU is greater than a threshold, the encoder or decoder splits the current CTU or CU into multiple blocks until each block is not greater than the threshold. The current CTU or CU is processed for prediction or compensation and transform or inverse transform. The current CTU is processed according to CTU-level syntaxes signaled in a video bitstream. The encoder or decoder encodes or decodes the current CTU. The threshold corresponds to a maximum supported transform unit (TU) size for the encoder or decoder.
Abstract:
A method and apparatus of motion compensation using the bi-directional optical flow (BIO) techniques are disclosed. According to one method, the use of BIO is extended to general bi-prediction motion compensation by including the case that two reference pictures correspond to two previously coded pictures. According to another method, the use of BIO is adaptively applied depending on the linearity of the two motion vectors associated with the two reference blocks or depending on block size of the current block. According to yet another method, the refined motion vectors by compensating the original motion vectors with the respective x-offset values and y-offset values are stored in a motion-vector buffer for motion vector prediction of one or more following blocks.
Abstract:
A method and apparatus of entropy coding of coding symbols using Context-Based Adaptive Binary Arithmetic Coder (CABAC) are disclosed. According to the present invention, CABAC encoding or decoding is applied to a current bin of a binary data of a current coding symbol according to a current probability for a binary value of the current bin and a current range associated with the current state of arithmetic coder. An LPS probability index corresponding to an inverted current probability or the current probability is derived depending on whether the current probability is greater than 0.5. A range index is derived for identifying one range interval containing the current range. An LPS range is then derived using one or more mathematical operations comprising calculating a multiplication of a first value related to the LPS probability index and a second value related to the range index n.
Abstract:
A method for encoding luma intra mode using context adaptive entropy processing determines a current luma intra mode for a current block and determines whether a neighboring block of the current block within a region of an independently coded slice is on a different side of a boundary of the region from the current block. The method replaces prediction mode information associated with the neighboring block by DC mode if the neighboring block is on the different side of the boundary of the region from the current block, and forms data for processing a current syntax element associated with the current luma intra mode based on the prediction mode information associated with the neighboring block. In addition, the method performs context adaptive entropy encoding processing on the current syntax element according to the formed data.
Abstract:
A method for adaptive MV precision is disclosed. According to one embodiment, whether to use or not to use the adaptive MV precision for a current block is determined according to a prediction mode/partition type of the current block. If the adaptive MV precision is used, a current MV precision is determined for a current MV of the current block, and the current MV is encoded or decoded at the current MV precision. If the adaptive MV precision is not used, the current MV is encoded or decoded at a finer MV precision. In another embodiment, a value of a current adaptive MV precision flag is selected for a current block to indicate whether to use or not to use the adaptive MV precision for a current block according to a prediction mode/partition type of the current block.
Abstract:
A method and apparatus for deriving aligned inter-view prediction for uni-prediction and bi-prediction in three-dimensional and multi-view coding with illumination compensation enabled are disclosed. When the illumination compensation is enabled, the derivation process for a single reference block in reference list_0 or reference list_1 in the case of uni-prediction is aligned with the derivation process for a reference block in reference list_0 and a reference block in reference list_1 in the case of bi-prediction. The reconstruction process generates the reference block based on a temporal reference block when Inter prediction is used and based on an inter-view reference block when inter-view prediction is used. For the uni-prediction and bi-prediction, the same clipping process can be included in the reconstruction process, the illumination compensation process, or both.