Abstract: In order to overcome the issue caused by a decoded block vector (BV) pointing to a reference block overlapping with an unavailable area, various methods are disclosed. According to one method, if the reference block overlaps with an unavailable area, the reference pixels in the unavailable area are generated for IntraBC prediction of the current block by padding from neighboring available pixels. The padding can be done in the horizontal direction and then the vertical direction. The padding may also done in the vertical direction first and then horizontal direction. In another method, if the reference block overlaps with an unavailable area, the reference pixels in the unavailable area are generated for IntraBC prediction of the current block by using previous decoded pixels in the unavailable area. A pre-defined value may also be used for the unavailable area.

Abstract: A method and apparatus for palette coding of a block of video data by initializing the palette or triplet palette or using a selected palette or triplet palette from a preceding image area for the beginning block of the current image area are disclosed. The method receives input data associated with a current image area consisting of multiple blocks. For the beginning block, the palette predictor is determined based on an initial palette or triplet palette or based on a selected palette or triplet palette associated with a selected block located at a location before the end of a preceding image area. For blocks of the current image area, palette coding is applied to the blocks, where at least one block uses the palette predictor for the beginning block as the palette predictor.

Abstract: A method of video coding with reduced implementation cost by reusing transform coefficient buffer palette for palette coding is disclosed. If the current prediction mode is an Intra prediction mode or the Inter prediction mode, information related to transform coefficients for prediction residual of the current block resulted from Intra prediction or Inter prediction is stored in the transform coefficient buffer. If the current prediction mode is the palette coding mode, information related to palette data associated with the current block is stored in the transform coefficient buffer. The current block is then encoded or decoded based on the information related to the transform coefficients if the current block is coded in the Intra prediction mode or the Inter prediction mode, or the information related to the palette data stored in the transform coefficient buffer if the current prediction mode is the palette coding mode.

Abstract: Motion compensated prediction using affine motion models can be used to improve coding efficiency. In a practical encoder/decoder, a line buffer is used to store associated data for neighboring blocks. Embodiments of affine model based motion compensated prediction include methods and systems of determining motion vectors for control points that are aware of line buffer storage limitations.

Abstract: A method and apparatus for color index coding of a block of video data using index prediction based on reconstructed neighboring pixels are disclosed. In one embodiment, color index encoding or decoding is applied to the current pixel indices by deriving index prediction from neighboring pixel indices of the reconstructed neighboring pixels. The reconstructed neighboring pixel values are first transformed into the neighboring pixel indices according to a quantization table to map between major color indices and major color values of the current block. The quantization table can be based on a major color table for the current block or can also be derived at a decoder side. The decoding process may reconstruct the current pixels by converting decoded current pixel indices to reconstructed current pixel values according to the quantization table or by directly copying the reconstructed neighboring pixel values indicated by decoded current pixel indices.

Abstract: A video coder, such as a video encoder or a video decoder, may use reference pixels in a first picture to pad pixels outside a picture boundary of a second picture. The second picture is a different picture from the first picture. The padded pixels are in a padding area surrounding the second picture. The video coder may encode or decode one or more blocks of the video data based on the padded pixels.

Abstract: A method of palette index map coding of blocks in a picture by grouping coded symbols of the same type is disclosed for video encoder and decoder. In one embodiment, all syntax elements corresponding to the pixel index are grouped into a pixel index group, and all syntax elements corresponding to the escape pixel are grouped into an escape pixel group. All syntax elements corresponding to the run type and run length are grouped into an interleaved run type/run length group, or grouped into separate run type group and run length group. In another embodiment, the system parses from the video bitstream a last-run mode syntax element for a current block, where the last-run mode syntax element indicates whether a last run mode is a copy-index mode or a copy-above mode. Information associated with the last-run mode syntax element is used for reconstructing palette index map.

Abstract: A method and apparatus for color index coding of a block of video data using index prediction based on reconstructed neighboring pixels are disclosed. In one embodiment, color index encoding or decoding is applied to the current pixel indices by deriving index prediction from neighboring pixel indices of the reconstructed neighboring pixels. The reconstructed neighboring pixel values are first transformed into the neighboring pixel indices according to a quantization table to map between major color indices and major color values of the current block. The quantization table can be based on a major color table for the current block or can also be derived at a decoder side. The decoding process may reconstruct the current pixels by converting decoded current pixel indices to reconstructed current pixel values according to the quantization table or by directly copying the reconstructed neighboring pixel values indicated by decoded current pixel indices.

Abstract: A video coder may determine a motion vector of a non-adjacent block of a current picture of the video data. The non-adjacent block is non-adjacent to a current block of the current picture. Furthermore, the video coder determines, based on the motion vector of the non-adjacent block, a motion vector predictor (MVP) for the current block. The video coder may determine a motion vector of the current block. The video coder may also determine a predictive block based on the motion vector of the current block.

Abstract: Methods for palette coding of image and video data to avoid issues associated with zero-size palette or to improve performance by conditionally signaling CU (coding unit)-level escape pixel presence flag are disclosed. In one embodiment, size information related to palette size of a current palette table of the current CU is signaled conditionally based on the escape indication flag, where the escape indication flag indicates whether there is any sample in the current CU coded as an escape pixel. In another embodiment, the CU-level escape pixel presence flag is conditionally signaled according to the current palette size or both of the predicted palette size and the new palette size. Conditionally signaling the palette sharing flag may also be based on the palette sharing flag.

Abstract: Techniques are described to increase the coding efficiency of information indicating a sign of a motion vector difference (MVD) component. A video coder may determine a MVD component sign predictor, and determine whether the MVD component sign predictor is the MVD component sign based on an indicator that is transmitted or received. In some examples, the indicator may be context coded, which promotes coding efficiencies.

Abstract: Techniques and systems are provided for deriving one or more sets of affine motion parameters at a decoder. For example, the decoder can obtain video data from an encoded video bitstream. The video data includes at least a current picture and a reference picture. The decoder can determine a set of affine motion parameters for a current block of the current picture. The set of affine motion parameters can be used for performing motion compensation prediction for the current block. The set of affine motion parameters can be determined using a current affine template of the current block and a reference affine template of the reference picture.

Abstract: A video encoder reconstructs pixels of a current block and applies a deblocking filter to the reconstructed pixels of the current block to derive deblocking-filtered reconstructed pixels of the current block. Furthermore, the video encoder calculates distortion values based on values of the deblocking-filtered reconstructed pixels of the current block and original pixels of the current block. The video encoder selects, based on the calculated distortion values, an encoding mode for the current block. The encoding mode for the current block is a partitioning mode for the current block or a coding unit mode for the current block.

Abstract: A method and apparatus of video coding incorporating Deep Neural Network are disclosed. A target signal is processed using DNN (Deep Neural Network), where the target signal provided to DNN input corresponds to the reconstructed residual, output from the prediction process, the reconstruction process, one or more filtering processes, or a combination of them. The output data from DNN output is provided for the encoding process or the decoding process. The DNN can be used to restore pixel values of the target signal or to predict a sign of one or more residual pixels between the target signal and an original signal. An absolute value of one or more residual pixels can be signalled in the video bitstream and used with the sign to reduce residual error of the target signal.

Abstract: Method and apparatus of video coding using decoder derived motion information based on bilateral matching or template matching are disclosed. According to one method, an initial motion vector (MV) index is signalled in a video bitstream at an encoder side or determined from the video bitstream at a decoder side. A selected MV is then derived using bilateral matching, template matching or both to refine an initial MV associated with the initial MV index. In another method, when both MVs for list 0 and list 1 exist in template matching, the smallest-cost MV between the two MVs may be used for uni-prediction template matching if the cost is lower than the bi-prediction template matching. According to yet another method, the refinement of the MV search is dependent on the block size. According to yet another method, merge candidate MV pair is always used for bilateral matching or template matching.

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: An example device for decoding video data includes a memory configured to store video data, and a video decoder implemented in circuitry and configured to determine that motion information of a current block of the video data is to be derived using decoder-side motion vector derivation (DMVD), determine a pixels clue for the current block, the pixels clue comprising pixel data obtained from one or more groups of previously decoded pixels, derive the motion information for the current block according to DMVD from the pixels clue, and decode the current block using the motion information. The video decoder may generate the pixels clue using multiple hypothesis predictions from multiple motion compensated blocks. The video decoder may determine an inter-prediction direction for the motion information according to matching costs between different prediction directions. The video decoder may refine the motion information using a calculated matching cost for the pixels clue.

Abstract: A video encoder is configured to determine whether to enable or disable an integer motion vector precision restriction and whether to enable or disable an illumination compensation (IC) tool by: for a large search range in a reference picture, performing first motion estimation tests, wherein performing the first motion estimation tests comprises performing motion estimation tests only with the IC tool disabled and the integer motion vector precision restriction disabled and with the IC tool enabled and the integer motion vector precision restriction disabled; based on the first motion estimation tests, determining a small search range, wherein the small search range is smaller than the large search range; for the small search range, performing second motion estimation tests; and based on the second motion estimation tests, determining whether to enable or disable the integer motion vector precision restriction and whether to enable or disable the IC tool.

Abstract: Methods of palette coding to reduce the required coding process are disclosed. According to one method, smaller blocks are derived from a large block. The histogram of the large block is derived based on the histograms of smaller blocks in the large block. According to another method, one or more palette tables are derived based on multiple blocks. One palette table is used for each of the multiple blocks. According to yet another method, index map transpose is performed in the parsing stage according to the transpose flag of the index map. Accordingly, a buffer to store the transpose flags can be saved. According to still yet another method, the palette predictor update is performed using an index mapping table to avoid the need for shuffling the contents of the palette predictor stored in a palette buffer.

Abstract: In order to overcome the issue caused by a decoded block vector (BV) pointing to a reference block overlapping with an unavailable area, various methods are disclosed. According to one method, if the reference block overlaps with an unavailable area, the reference pixels in the unavailable area are generated for IntraBC prediction of the current block by padding from neighbouring available pixels. The padding can be done in the horizontal direction and then the vertical direction. The padding may also done in the vertical direction first and then horizontal direction. In another method, if the reference block overlaps with an unavailable area, the reference pixels in the unavailable area are generated for IntraBC prediction of the current block by using previous decoded pixels in the unavailable area. A pre-defined value may also be used for the unavailable area.