Abstract: A video processing method includes receiving a bitstream, processing the bitstream to obtain at least one syntax element from the bitstream, and decoding the bitstream to generate a current decoded frame having a rotated 360-degree image/video content represented in a 360-degree Virtual Reality (360 VR) projection format. The at least one syntax element signaled via the bitstream indicates rotation information of content-oriented rotation that is involved in generating the rotated 360-degree image/video content, and includes a first syntax element. When the content-oriented rotation is enabled, the first syntax element indicates a rotation degree along a specific rotation axis.

Abstract: Methods and apparatus of processing spherical images related to segmented sphere projection (SSP) are disclosed. According to one method, a North Pole region of the spherical image is projected to a first circular image and a South Pole region of the spherical image is projected to a second circular image using a mapping process selected from a mapping group comprising equal-area mapping, non-uniform mapping and cubemap mapping. Methods and apparatus of processing spherical images related to rotated sphere projection (RSP) are also disclosed. According to this method, the spherical image is projected into a first part of rotated sphere projection corresponding to a ?×? region of the spherical image and a second part of rotated sphere projection corresponding to a remaining part of the spherical image using equal-area mapping.

Abstract: A video processing method includes: receiving an omnidirectional image/video content corresponding to a viewing sphere, generating a sequence of projection-based frames according to the omnidirectional image/video content and a viewport-based cube projection layout, and encoding the sequence of projection-based frames to generate a bitstream. Each projection-based frame has a 360-degree image/video content represented by rectangular projection faces packed in the viewport-based cube projection layout. The rectangular projection faces include a first rectangular projection face, a second rectangular projection face, a third rectangular projection face, a fourth rectangular projection face, a fifth rectangular projection face, and a sixth rectangular projection face split into partial rectangular projection faces.

Abstract: A video processing method includes: receiving a current input frame having a 360-degree image/video content represented in a 360-degree Virtual Reality (360 VR) projection format, applying content-oriented rotation to the 360-degree image/video content in the current input frame to generate a content-rotated frame having a rotated 360-degree image/video content represented in the 360 VR projection format, encoding the content-rotated frame to generate a bitstream, and signaling at least one syntax element via the bitstream, wherein the at least one syntax element is set to indicate rotation information of the content-oriented rotation.

Abstract: A video encoding method includes: setting a 360-degree Virtual Reality (360 VR) projection layout of projection faces, wherein the projection faces have a plurality of triangular projection faces located at a plurality of positions in the 360 VR projection layout, respectively; encoding a frame having a 360-degree image content represented by the projection faces arranged in the 360 VR projection layout to generate a bitstream; and for each position included in at least a portion of the positions, signaling at least one syntax element via the bitstream, wherein the at least one syntax element is set to indicate at least one of an index of a triangular projection view filled into a corresponding triangular projection face located at the position and a rotation angle of content rotation applied to the triangular projection view filled into the corresponding triangular projection face located at the position.

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 an octahedron projection layout. An omnidirectional image/video content of a viewing sphere is mapped onto the triangular projection faces via an octahedron 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: An audio synchronization method includes: receiving a first audio signal from a first recording device; receiving a second audio signal from a second recording device; performing a correlation operation upon the first audio signal and the second audio signal to align a first pattern of the first audio signal and the first pattern of the second audio signal; after the first patterns of the first audio signal and the second audio signal are aligned, calculating a difference between a second pattern of the first audio signal and the second pattern of the second audio signal; and obtaining a starting-time difference between the first audio signal and the second audio signal for audio synchronization according to the difference between the second pattern of the first audio signal and the second pattern of the second audio signal.

Abstract: A video processing method includes receiving a bitstream, processing the bitstream to obtain at least one syntax element from the bitstream, and decoding the bitstream to generate a current decoded frame having a rotated 360-degree image/video content represented in a 360-degree Virtual Reality (360 VR) projection format. The at least one syntax element signaled via the bitstream indicates rotation information of content-oriented rotation that is involved in generating the rotated 360-degree image/video content, and includes a first syntax element. When the content-oriented rotation is enabled, the first syntax element indicates a rotation degree along a specific rotation axis.

Abstract: A video processing method includes: receiving an omnidirectional image/video content corresponding to a viewing sphere, generating a sequence of projection-based frames according to the omnidirectional image/video content and an octahedron projection layout, and encoding, by a video encoder, the sequence of projection-based frames to generate a bitstream. Each projection-based frame has a 360-degree image/video content represented by triangular projection faces packed in the octahedron projection layout. The omnidirectional image/video content of the viewing sphere is mapped onto the triangular projection faces via an octahedron 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: 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: 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: Methods and apparatus of processing cube face images are disclosed. According one method, each set of six cubic faces is converted into one rectangular assembled image by assembling each set of six cubic faces to maximize a number of continuous boundaries and to minimize a number of discontinuous boundaries. Each continuous boundary corresponds to one boundary between two connected faces with continuous contents from one face to another face. Each discontinuous boundary corresponds to one boundary between two connected faces with discontinuous contents from one face to another face. The method may further comprise applying video coding to the video sequence outputting the compressed data of the video sequence. According to another method, a fully-connected cubic-face image representing an unfolded image from the six faces of the cube is generated and the blank areas are filled with padding data to form a rectangular assembled image.

Abstract: A video processing method includes obtaining projection face(s) from an omnidirectional content of a sphere, and obtaining a re-sampled projection face by re-sampling at least a portion of a projection face of the projection face(s) through non-uniform mapping. The omnidirectional content of the sphere is mapped onto the projection face(s) via a 360-degree Virtual Reality (360 VR) projection. The projection face has a first source region and a second source region. The re-sampled projection face has a first re-sampled region and a second re-sampled region. The first re-sampled region is derived from re-sampling the first source region with a first sampling density. The second re-sampled region is derived from re-sampling the second source region with a second sampling density that is different from the first sampling density.

Abstract: Methods and apparatus of processing cube face images are disclosed. According one method, each set of six cubic faces is converted into one rectangular assembled image by assembling each set of six cubic faces to maximize a number of continuous boundaries and to minimize a number of discontinuous boundaries. Each continuous boundary corresponds to one boundary between two connected faces with continuous contents from one face to another face. Each discontinuous boundary corresponds to one boundary between two connected faces with discontinuous contents from one face to another face. The method may further comprise applying video coding to the video sequence outputting the compressed data of the video sequence. According to another method, a fully-connected cubic-face image representing an unfolded image from the six faces of the cube is generated and the blank areas are filled with padding data to form a rectangular assembled image.

Abstract: A method and apparatus of video encoding or decoding for a video encoding or decoding system applied to multi-face sequences corresponding to a 360-degree virtual reality sequence are disclosed. According the present invention, one or more multi-face sequences representing the 360-degree virtual reality sequence are derived. If Inter prediction is selected for a current block in a current face, one virtual reference frame is derived for each face of said one or more multi-face sequences by assigning one target reference face to a center of said one virtual reference frame and connecting neighboring faces of said one target reference face to said one target reference face at boundaries of said one target reference face. Then, the current block in the current face is encoded or decoded using a current virtual reference frame derived for the current face to derive an Inter predictor for the current block.

Abstract: Methods and apparatus of processing omnidirectional images are disclosed. According to one method, a current set of omnidirectional images converted from each spherical image in a 360-degree panoramic video sequence using a selected projection format is received, where the selected projection format belongs to a projection format group comprising a cubicface format, and the current set of omnidirectional images with the cubicface format consists of six cubic faces. If the selected projection format corresponds to the cubicface format, one or more mapping syntax elements to map the current set of omnidirectional images into a current cubemap image are signaled. The coded data are then provided in a bitstream including said one or more mapping syntax elements for the current set of omnidirectional images.

Abstract: A projection-based frame is generated according to an omnidirectional video frame and an octahedron projection layout. The projection-based frame has a 360-degree image content represented by triangular projection faces assembled in the octahedron projection layout. A 360-degree image content of a viewing sphere is mapped onto the triangular projection faces via an octahedron projection of the viewing sphere. One side of a first triangular projection face has contact with one side of a second triangular projection face, one side of a third triangular projection face has contact with another side of the second triangular projection face. One image content continuity boundary exists between one side of the first triangular projection face and one side of the second triangular projection face, and another image content continuity boundary exists between one side of the third triangular projection face and another side of the second triangular projection face.

Abstract: According to one method, at a source side or an encoder side, a selected viewport associated with the 360-degree virtual reality images is determined. One or more parameters related to the selected pyramid projection format are then determined. According to the present invention, one or more syntax elements for said one or more parameters are included in coded data of the 360-degree virtual reality images. The coded data of the 360-degree virtual reality images are provided as output data. At a receiver side or a decoder side, one or more syntax elements for one or more parameters are parsed from the coded data of the 360-degree virtual reality images. A selected pyramid projection format associated with the 360-degree virtual reality images is determined based on information including said one or more parameters. The 360-degree virtual reality images are then recovered according to the selected viewport.

Abstract: Methods and apparatus of processing 360-degree virtual reality images are disclosed. According to one method, a 2D (two-dimensional) frame is divided into multiple blocks. The multiple blocks are encoded or decoded using quantization parameters by restricting a delta quantization parameter to be within a threshold for any two blocks corresponding to two neighboring blocks on a 3D sphere. According to another embodiment, one or more guard bands are added to one or more edges that are discontinuous in the 2D frame but continuous in the 3D sphere. Fade-out process is applied to said one or more guard bands to generate one or more faded guard bands. At the decoder side, the reconstructed 2D frame is generated from the decoded extended 2D frame by cropping said one or more decoded faded guard bands or by blending said one or more decoded faded guard bands and reconstructed duplicated areas.

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.