Abstract: A method and apparatus for scalable video coding are disclosed, wherein the video data is configured into a Base Layer (BL) and an Enhancement Layer (EL) and wherein the EL has higher spatial resolution or better video quality than the BL. According to embodiments of the present invention, information from the base layer is exploited for coding the enhancement layer. The information coding for the enhancement layer includes CU structure, motion information, motion information, MVP/merge candidates, intra prediction mode, residual quadtree information, texture information, residual information, context adaptive entropy coding, Adaptive Lop Filter (ALF), Sample Adaptive Offset (SAO), and deblocking filter.

Abstract: The method selects a region for processed video data and determines a class for each pixel in the region of the processed video data based on characteristic measurement of said each pixel. The processed video data corresponds to the reconstructed, deblocked reconstructed or deblocked-and-loop-filtered reconstructed video data. An intensity offset is then determined for the class according to the pixels in the region of the processed video data and respective pixels in a respective region of associated original video data. The intensive offset determined is applied to the processed video data to compensate the intensity offset. The region is smaller than a picture so that adaptive offset can adapt to dynamic characteristics of a picture. In one embodiment, the characteristic measurement is based on pixel patterns consisting pixels around an underlying pixel.

Abstract: An apparatus and method for video coding based on flexible slice structure are disclosed. In the recent high efficiency video coding (HEVC) development, the slice may contain multiple LCUs instead of macroblocks. The LCU size being considered is 64×64 pixels which is much larger than the macroblock size of 16×16 pixels. Compared with the macroblock aligned slice for H.264, the LCU-aligned slice for HEVC does not provide enough granularities for dividing video frames. Consequently, a flexible slice structure is developed where slice partition is based on smaller coding units. In the flexible slice structure, the first LCU and the last LCU of the slice are allowed to be a fractional LCU, which is derived from a whole LCU using quadtree partition. Syntax elements are also developed to enable conveyance of flexible slice structure between an encoder and a decoder efficiently.

Abstract: A method and apparatus for scalable video coding are disclosed, wherein the video data is configured into a Base Layer (BL) and an Enhancement Layer (EL) and wherein the EL has higher spatial resolution or better video quality than the BL. According to embodiments of the present invention, information from the base layer is exploited for coding the enhancement layer. The information coding for the enhancement layer includes CU structure, motion vector predictor (MVP) information, MVP/merge candidates, intra prediction mode, residual quadtree information, texture information, residual information, context adaptive entropy coding, Adaptive Lop Filter (ALF), Sample Adaptive Offset (SAO), and deblocking filter.

Abstract: A method and apparatus for in-loop processing of reconstructed video are disclosed. The method and apparatus configure the in-loop processing so that the processing requires no pixel or reduced pixels from other side of a virtual boundary. When the in-loop processing of the to-be-processed pixel requires a pixel from the other side of the virtual boundary, the pixel from the other side of the virtual boundary is replaced by a replacement pixel. The in-loop processing can also be configured to skip the pixel when the processing requires a pixel from other side of the virtual boundary. The in-loop processing can also be configured to change ALF filter shape or filter size when the in-loop processing requires a pixel from other side of the virtual boundary. A filtered output can be combined linearly or nonlinearly with the to-be-processed pixel to generate a final filter output.

Abstract: A method and apparatus for processing of coded video using adaptive offset (AO) are disclosed. Embodiments of the present invention divide reconstructed video data into multiple filter units and apply adaptive offset to the filter units to generate filtered video data, where boundaries of filter units correspond to boundaries of coding units and each of said filter units contains at least one coding unit. Furthermore, two or more of the multiple filter units can be merged as indicated by a merge index to share the applied adaptive offset. A filter control flag can be used to indicate filter ON/OFF control. The luma and chroma components may also share the same filter information. In another embodiment, the filter information sharing among filter units can be applied regardless whether the boundaries of the filter units are aligned with the boundaries of the coding units.

Abstract: Methods and apparatuses for video decoding and encoding with in-loop processing of reconstructed video are disclosed. At the decoder side, the method comprises receiving a flag from the video bitstream and according to the flag, the method receives information associated with in-loop filter parameters either from a data payload in the video bitstream to be shared by two or more coding blocks or individual coding block data in the video bitstream. At the encoder side, the method comprises incorporating information associated with the in-loop filter parameters either in a data payload in a video bitstream to be shared by two or more coding blocks or interleaved with individual coding block data in the video bitstream according to a flag. The data payload in the video bitstream is in a picture level, Adaptation Parameter Set (APS), or a slice header.

Abstract: A video encoder that utilizes adaptive loop filtering for coding video data includes: a prediction unit, for performing prediction techniques according to original video data and reconstructed video data to generate predicted samples; a reconstruction unit, for reconstructing the predicted samples to form the reconstructed video data; a reference picture buffer, for storing the reconstructed video data; a filter parameter estimator, for estimating filter parameters according to the original video data and the reconstructed video data; and an adaptive filter, for utilizing the stored filter parameters to perform filtering on the reconstructed video data.

Abstract: Methods for filter-unit based in-loop filtering in a video decoder and encoder are disclosed. In one embodiment, filter parameters are selected from a filter parameter set for each filter based on a filter index. In another embodiment, the picture is partitioned into filter units according to filter unit size, which can be selected between a default size and other size. When other size is selected, the filter unit size may be conveyed using direct size information or ratio information. In another embodiment, a merge flag and a merge index are used to convey filter unit merge information. A method for filter-unit based in-loop filtering in a video encoder for color video is disclosed. In one embodiment, the method incorporates filter syntax in the video bitstream by interleaving the color-component filter syntax for the FUs.

Abstract: A method and apparatus for deriving a motion vector predictor (MVP) are disclosed. The MVP is selected from spatial MVP and temporal MVP candidates. The method uses a flag to indicate whether temporal MVP candidates are disabled. If the flag indicates that the temporal MVP candidates are disabled, the MVP is derived from the spatial MVP candidates only. Otherwise, the MVP is derived from the spatial and temporal MVP candidates. The method may further skip spatial redundant MVP removal by comparing MV values. Furthermore, the parsing error robustness scheme determines a forced temporal MVP when a temporal MVP is not available and the temporal MVP candidates are allowed as indicated by the flag. The flag may be incorporated in sequence, picture, slice level, or a combination of these levels.

Abstract: A method and apparatus for video processing of reconstructed video in a reconstruction loop are disclosed. An embodiment according to the present invention performs padding for the blocks in the slice boundaries according to a processing order. Each of the one or more reconstructed blocks at slice boundaries is padded according to a padding order. In-loop filtering is applied to the reconstructed slice according to the processing order, wherein the reconstructed slice is filtered by referencing the one or more padded blocks. The padding order can be vertical-edge first and then horizontal-edge, or horizontal-edge first and then vertical-edge. Various embodiments are disclosed regarding whether padding for a later padded block in the processing order is skipped or not in the overlapped area. The present invention is also applied to adaptation blocks for block-based in-loop filtering in slice boundaries.

Abstract: A video encoder includes a prediction unit for performing prediction techniques according to original video data and reconstructed video data to generate prediction samples, a reconstruction unit for reconstructing the prediction samples to form the reconstructed video data, and a reference picture buffer for storing the reconstructed video data as reference video data. The video encoder also includes a filter parameter estimator for estimating filter parameters according to the original video data of a current picture and the reconstructed video data of the current picture, and an adaptive loop filter for filtering the reconstructed video data of the current picture according to stored filter parameters of a prior picture in coding order. The filter parameter estimator and adaptive loop filter can operate in parallel.

Abstract: A method and apparatus for processing reconstructed video using in-loop filter in a video coding system are disclosed. The method uses chroma in-loop filter indication to indicate whether chroma components are processed by in-loop filter when the luma in-loop filter indication indicates that in-loop filter processing is applied to the luma component. An additional flag may be used to indicate whether the in-loop filter processing is applied to an entire picture using same in-loop filter information or each block of the picture using individual in-loop filter information. Various embodiments according to the present invention to increase efficiency are disclosed, wherein various aspects of in-loop filter information are taken into consideration for efficient coding such as the property of quadtree-based partition, boundary conditions of a block, in-loop filter information sharing between luma and chroma components, indexing to a set of in-loop filter information, and prediction of in-loop filter information.

Abstract: A method and apparatus for sharing information in a video coding system are disclosed. Embodiments according to the present invention use an information sharing flag to determine whether to share in-loop filter information in the picture level. The information sharing flag may be incorporated in the sequence level, the picture level or the slice level to indicate whether information sharing is enabled. Multiple information sharing flags may also be used to adaptively control information sharing. Furthermore, method and apparatus of using multiple Adaptation Parameter Sets (APSs) for information sharing of in-loop filters are disclosed. APS identifiers of in-loop filters may be incorporated in the slice header to allow each of the in-loop filters select respective filter information from the multiple APSs. A flag is incorporated in SPS to indicate whether multiple APS or single APS is used. Various exemplary syntax designs are disclosed to illustrate information sharing.

Abstract: An apparatus and method for sample adaptive offset to restore intensity shift of processed video data are described. In a video coding system, the video data are subject to various processing such as prediction, transformation, quantization, deblocking, and adaptive loop filtering. Along the processing path in the video coding system, certain characteristics of the processed video data may be altered from the original video data due to the operations applied to video data. For example, the mean value of the processed video may be shifted. Therefore, the pixel intensity shift has to be carefully compensated or restored to alleviate the artifacts. Accordingly a sample adaptive offset scheme is disclosed that can take into consideration of the dynamic characteristics within a frame using a region partition scheme. Furthermore, the sample adaptive offset scheme also supports multiple SAO types that can be tailored to the characteristics of processed video data and achieve better quality.

Abstract: For sample adaptive offset, classification may be used to classify the pixels into multiple categories and pixels in each category are offset compensated using an offset value for the category. The classification may be based on values of the current pixel and its neighboring pixels before SAO compensation. Therefore, the SAO compensated pixel cannot be written back to the current pixel location until the category for all pixels are determined. An embodiment of the present invention stores the relation between the current pixel and said one or more neighboring pixels so that the SAO compensated current pixel can replace the current pixel without buffering the to-be-processed pixels for classification. The SAO process may be performed on a region by region basis to adapt to the local characteristics of the picture. Rate-distortion optimization (RDO) is often used to guide the mode decision, such as region splitting/region merging decision.

Abstract: In the current high efficiency video coding development, each LCU has its own quantization parameter (QP) and the difference between a current QP and a reference QP is transmitted instead of the QP value itself. Since the LCU is much larger than the macroblock of AVC/H.264, using one delta QP per LCU may cause rate control unable to adapt to the bitrate quickly enough. Consequently there is a need to adopt delta QP in units smaller than LCU to provide more granular rate control. Furthermore, it is desirable to develop a system that is capable of facilitating more flexible delta QP. Accordingly, adaptive quantization parameter processing is disclosed where a QP minimum CU size for incorporating or deriving a delta QP is indicated selectively in the slice level or in the sequence/picture level. In one variation, the delta QP is incorporated or derived only if nonzero quantized transform coefficients exist in a leaf CU that is larger than the QP minimum CU size.

Abstract: An apparatus and method for video coding based on flexible slice structure are disclosed. In the recent high efficiency video coding (HEVC) development, the slice may contain multiple LCUs instead of macroblocks. The LCU size being considered is 64×64 pixels which is much larger than the macroblock size of 16×16 pixels. Compared with the macroblock aligned slice for H.264, the LCU-aligned slice for HEVC does not provide enough granularities for dividing video frames. Consequently, a flexible slice structure is developed where slice partition is based on smaller coding units. In the flexible slice structure, the first LCU and the last LCU of the slice are allowed to be a fractional LCU, which is derived from a whole LCU using quadtree partition. Syntax elements are also developed to enable conveyance of flexible slice structure between an encoder and a decoder efficiently.

Abstract: An apparatus and method for video coding having intra-slice deblocking, intra-slice adaptive loop filter, and intra-slice adaptive offset are disclosed. In a video coding system, a picture is often divided into slices and each slice is independently processed so that errors or missing data from one slice cannot propagate to any other slice within the picture. In the recent high efficiency video coding (HEVC) development, deblock filtering (DF), adaptive loop filter (ALF) and adaptive offset (AO) may be applied to reconstructed slices. When the processing is applied across slice boundaries, it may rely on pixels outside the current slice and cause dependency of the current slice on other slice(s). Consequently, the DF/ALF/AO processing on a reconstructed slice may have to wait until the reconstructed slices that it is dependent from complete the DF/ALF/AO processing. To overcome the slice boundary issue, intra-slice DF/ALF/AO is developed that does not rely on any pixel outside the currently slice.

Abstract: In the H.264/AVC standard, one of the new characteristics is the possibility of dividing an image in regions called slice groups. The use of slice groups provides various possible advantages such as prioritized transmission, error resilient transmission, and etc. The slice groups can be formed by flexible macroblock ordering (FMO), where each picture can be divided into slice groups in different scan patterns of the macroblocks. In the high efficiency video coding (HEVC) under development, a more flexible block structure, called coding unit (CU), is used as the unit to process video data. The picture is first divided into largest CUs (LCUs) and each LCU is adaptively split into smaller CUs using a quadtree until leaf CUs are reached. In the current HEVC development, there is neither slice nor slice group structure being considered. The LCU size used for HEVC is 16 times as large as the macroblock size used in the H.264/AVC standard.