Abstract: Methods and apparatus of coding a video sequence, wherein pictures from the video sequence contain one or more discontinuous edges are disclosed. The loop filtering process associated with the loop filter is then applied to the current reconstructed pixel to generate a filtered reconstructed pixel, where if the loop filtering process is across a virtual boundary of the current picture, one or more alternative reference pixels are used to replace unexpected reference pixels located in a different side of the virtual boundary from the current reconstructed pixel, and said one or more alternative reference pixels are generated from second reconstructed pixels in a same side of the virtual boundary as the current reconstructed pixel. According to another method, reference pixels are derived from spherical neighbouring reference pixels for the loop filtering process.

Abstract: A video decoding method includes decoding a part of a bitstream to generate a decoded frame. The decoded frame is a projection-based frame that comprises at least one projection face and at least one guard band packed in a projection layout. At least a portion of a 360-degree content of a sphere is mapped to the at least one projection face via projection. The decoded frame is in a 4:2:0 chroma format or a 4:2:2 chroma format, and a guard band size of each of the at least one guard band is equal to an even number of luma samples.

Abstract: Method and apparatus of coding a video sequence are disclosed. According to this method, a first syntax is signalled in or parsed from a bitstream, where the first syntax indicates whether a loop filtering process is disabled for one or more virtual boundaries in a corresponding region. A reconstructed filter unit in a current picture is received, wherein the reconstructed filter unit is associated with the loop filter and the reconstructed filter unit comprises reconstructed pixels for applying a loop filtering process associated with the loop filter to a current reconstructed pixel. When the first syntax is true, the loop filter processing is disabled when the reconstructed filter unit is across said one or more virtual boundaries in the corresponding region. When the first syntax is false, the loop filter processing is not disabled when the reconstructed filter unit is across the virtual boundary.

Abstract: A method and apparatus for coding a depth block in three-dimensional video coding are disclosed. Embodiments of the present invention divide a depth block into depth sub-blocks and determine default motion parameters. For each depth sub-block, the motion parameters of a co-located texture block covering the center sample of the depth sub-block are determined. If the motion parameters are available, the motion parameters are assigned as inherited motion parameters for the depth sub-block. If the motion parameters are unavailable, the default motion parameters are assigned as inherited motion parameters for the depth sub-block. The depth sub-block is then encoded or decoded using the inherited motion parameters or a motion candidate selected from a motion candidate set including the inherited motion parameters. The depth block may correspond to a depth prediction unit (PU) and the depth sub-block corresponds to a depth sub-PU.

Abstract: A video processing method includes: obtaining a plurality of square projection faces from an omnidirectional content of a sphere according to a cube-based projection, scaling the square projection faces to generate a plurality of scaled projection faces, respectively, creating at least one padding region, generating a projection-based frame by packing the scaled projection faces and said at least one padding region in a projection layout of the cube-based projection, and encoding the projection-based frame to generate a part of a bitstream.

Abstract: A video processing method includes receiving a reconstructed frame, and applying in-loop filtering, by at least one in-loop filter, to the reconstructed frame. The step of in-loop filtering includes performing a sample adaptive offset (SAO) filtering operation. The step of performing the SAO filtering operation includes keeping a value of a current pixel unchanged by blocking the SAO filtering operation of the current pixel included in the reconstructed frame from being applied across a virtual boundary defined in the reconstructed frame.

Abstract: A video processing method includes: receiving an omnidirectional content corresponding to a sphere, obtaining projection faces from the omnidirectional content, and creating a projection-based frame by generating at least one padding region and packing the projection faces and said at least one padding region in a 360 VR projection layout. The projection faces packed in the 360 VR projection layout include a first projection face and a second projection face, where there is an image content discontinuity edge between the first projection face and the second projection face if the first projection face connects with the second projection face. The at least one padding region packed in the 360 VR projection layout includes a first padding region, where the first padding region connects with the first projection face and the second projection face for isolating the first projection face from the second projection face in the 360 VR projection layout.

Abstract: A video decoding method includes: decoding a part of a bitstream to generate a decoded frame, including parsing a syntax element from the bitstream. The decoded frame is a projection-based frame that includes at least one projection face and at least one guard band packed in a projection layout with padding, and at least a portion of a 360-degree content of a sphere is mapped to the at least one projection face via projection. The syntax element specifies a guard band type of the at least one guard band.

Abstract: Methods and apparatus of processing 360-degree virtual reality images are disclosed. According to one method, the method receives coded data for an extended 2D (two-dimensional) frame including an encoded 2D frame with one or more encoded guard bands, wherein the encoded 2D frame is projected from a 3D (three-dimensional) sphere using a target projection, wherein said one or more encoded guard bands are based on a blending of one or more guard bands with an overlapped region when the overlapped region exists. The method then decodes the coded data into a decoded extended 2D frame including a decoded 2D frame with one or more decoded guard bands, and derives a reconstructed 2D frame from the decoded extended 2D frame.

Abstract: A video processing method includes: obtaining a plurality of projection faces from an omnidirectional content of a sphere, wherein the omnidirectional content of the sphere is mapped onto the projection faces via cubemap projection, and the projection faces comprise a first projection face; obtaining, by a re-sampling circuit, a first re-sampled projection face by re-sampling at least a portion of the first projection face through non-uniform mapping; generating a projection-based frame according to a projection layout of the cubemap projection, wherein the projection-based frame comprises the first re-sampled projection face packed in the projection layout; and encoding the projection-based frame to generate a part of a bitstream.

Abstract: A method and apparatus of priority-based MVP (motion vector predictor) derivation for motion compensation in a video encoder or decoder are disclosed. According to this method, one or more final motion vector predictors (MVPs) are derived using priority-based MVP derivation process. The one or more final MVPs are derived by selecting one or more firstly available MVs from a priority-based MVP list for Inter prediction mode, Skip mode or Merge mode based on reference data of one or two target reference pictures that are reconstructed prior to the current block according to a priority order. Therefore, there is no need for transmitting information at the encoder side nor deriving information at the decoder side that is related to one or more MVP indices to identify the one or more final MVPs in the video bitstream.

Abstract: A video decoding method includes decoding a part of a bitstream to generate a decoded frame. The decoded frame is a projection-based frame that comprises at least one projection face and at least one guard band packed in a projection layout. At least a portion of a 360-degree content of a sphere is mapped to the at least one projection face via projection. The decoded frame is in a 4:2:0 chroma format or a 4:2:2 chroma format, and a guard band size of each of the at least one guard band is equal to an even number of luma samples.

Abstract: A sample adaptive offset (SAO) filtering method for a reconstructed projection-based frame includes: obtaining at least one padding pixel in a padding area that acts as an extension of a face boundary of a first projection face, and applying SAO filtering to a block that has at least one pixel included in the first projection face. In the reconstructed projection-based frame, there is image content discontinuity between the face boundary of the first projection face and a face boundary of a second projection face. The at least one padding pixel is involved in the SAO filtering of the block.

Abstract: Methods and apparatus of processing cube face images are disclosed. According to embodiments of the present invention, one or more discontinuous boundaries within each assembled cubic frame are determined and used for selective filtering, where the filtering process is skipped at said one or more discontinuous boundaries within each assembled cubic frame when the filtering process is enabled. Furthermore, the filtering process is applied to one or more continuous areas in each assembled cubic frame.

Abstract: A video processing method includes receiving a bitstream, and decoding, by a video decoder, the bitstream to generate a decoded frame. The decoded frame is a projection-based frame that has a 360-degree image/video content represented by triangular projection faces packed in a triangle-based projection layout. An omnidirectional image/video content of a viewing sphere is mapped onto the triangular projection faces via a triangle-based projection of the viewing sphere. An equator of the viewing sphere is not mapped along any side of each of the triangular projection faces.

Abstract: A method and apparatus for Intra prediction of non-square chroma blocks are disclosed. The system uses a block partitioning structure for partitioning a chroma block into one or more final sub-blocks including at least one non-square final sub-block using block partition recursively. The block partition either splits each given block into intermediate sub-blocks using one or more split modes including one binary split mode or applies no splitting to each given block. The block is treated as an initial given block and each intermediate sub-block is treated as one given block in a next recursion. Any given block that is not further split becomes a final sub-block. After the final sub-blocks are determined, non-square Intra prediction is applied to each non-square final sub-block.

Abstract: A luma-based chroma intra-prediction method includes: applying, by a filter circuit with a first weighting table, weighting to reconstructed luma samples to generate a first down-sampled luma sample, wherein the reconstructed luma samples are external to a luma block; computing parameters of a linear model, wherein a pair of the first down-sampled luma sample and a reconstructed chroma sample that is external to a chroma block is involved in computing the parameters of the linear model; and determining a predicted value of a chroma sample included in the chroma block according to the linear model and a second down-sampled luma sample that is derived from the luma block.

Abstract: A cube-based projection method includes generating pixels of different square projection faces associated with a cube-based projection of a 360-degree image content of a sphere. Pixels of a first square projection face are generated by utilizing a first mapping function set. Pixels of a second square projection face are generated by utilizing a second mapping function set. The different square projection faces include the first square projection face and the second square projection face. The second mapping function set is not identical to the first mapping function set.

Abstract: A video decoding method includes: decoding a part of a bitstream to generate a decoded frame, and parsing at least one syntax element from the bitstream. The decoded frame is a projection-based frame that includes projection faces packed in a cube-based projection layout. At least a portion of a 360-degree content of a sphere is mapped to the projection faces via cube-based projection. The at least one syntax element is indicative of a guard band configuration of the projection-based frame.

Abstract: A video encoding method includes: encoding a projection-based frame to generate a part of a bitstream, wherein at least a portion of a 360-degree content of a sphere is mapped to projection faces via cube-based projection, and the projection-based frame has the projection faces packed in a cube-based projection layout; and signaling at least one syntax element via the bitstream, wherein said at least one syntax element is associated with a mapping function that is employed by the cube-based projection to determine sample locations for each of the projection faces.