WO2019089382A1

WO2019089382A1 - 360-degree video coding using face-based geometry padding

Info

Publication number: WO2019089382A1
Application number: PCT/US2018/057757
Authority: WO
Inventors: Philippe HANHART; Yuwen He; Yan Ye
Original assignee: Vid Scale, Inc.
Priority date: 2017-10-31
Filing date: 2018-10-26
Publication date: 2019-05-09

Abstract

A frame-packed picture for a 360-degree video content may be received, A group of continuous faces in the frame-packed picture may be identified based on frame packing information for the frame-packed picture. A sample Iocation in the group of continuous faces may be identified. Whether a neighboring sample Iocation associated with the identified sample location is located outside of a discontinuous edge of the group of continuous faces may be determined. If the neighboring sample iocation is located outside of the discontinuous edge of the group of continuous faces, geometry padding on the identified sample Iocation may be performed, if the neighboring sample Iocation is located outside of the discontinuous edge of the group of continuous faces, geometry padding may be skipped. The 360-degree video content may be processed based on the geometry padding.

Description

360-DEGREE VIDEO CODING USING FACE-BASED GEOMETRY PADDING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 62/579,533 filed October 31 , 2017, the contents of which are incorporated by reference herein.

BACKGROUND

[0002] Virtual reality (VR) is increasingly entering our daily lives. VR has many application areas, including healthcare, education, social networking, industry design/training, game, movie, shopping, entertainment, etc. VR is gaining attention from industries and consumers because VR is capable of bringing an immersive viewing experience. VR creates a virtual environment surrounding the viewer and generates a true sense of "being there" for the viewer. How to provide the full real feeling in the VR environment is important for a user's experience. For example, the VR system may support interactions through posture, gesture, eye gaze, voice, etc. To allow the user to interact with objects in the VR world in a natural way, the VR may provide haptic feedback to the user.

SUiiARY

[0003] Geometry padding for 360-degree video coding may be performed by padding a group of continuous faces and/or clipping motion vectors based on coding unit (CD) positions. A group ef faces may be padded (e.g., padded jointly). Padding may be skipped, for example, at the boundaries between continuous faces. Motion vector clipping may be performed based on the CU coordinates within a face and/or a group of continuous faces. The CU may be translated to cover a padded area (e.g., the whole padded area).

[0004] As used herein, 360-degree videos may include omni-directional videos, spherical videos, six degree of freedom (6DoF) media, monoscopic and stereoscopic (3D) virtual reality videos, and/or the like.

[0005] A frame-packed picture for the 360-degree video content may be received, e.g., for coding a 360- degegree video content. A group of continuous faces in the frame-packed picture may be identified. For example, a group of continuous faces in the frame-packed picture may be identified based on frame packing information for the frame-packed picture. A sample location in the group of continuous faces may be identified. [0008] Whether a neighboring sampie location associated with the identified sample location is located outside of a discontinuous edge of the group of continuous faces may be determined. In examples, if the identified sampie location is at a first face boundary of a face in the group of continuous faces, whether content across the first face boundary is continuous may be determined, e.g., based on the frame packing information. Based on a determination that the content across the first face boundary is continuous, it may be determined that the neighboring sample location associated with the identified sample location is not located outside of a discontinuous edge of the group of continuous faces. Based on a determination that the content across the first face boundary is discontinuous, the first face boundary may be tagged as a discontinuous edge. Whether the neighboring sample location associated with the identified sampie location is located outside of the first face boundary may be determined.

[0007] if the neighboring sample location is located outside of the discontinuous edge of the group of continuous faces, geometry padding may be performed on the identified sample location. The 360-degree video content may be processed based on the geometry padding, in examples, geometry padding may be performed by one or more of the following. The closest face to the identified sample location located outside of the discontinuous edge of the group of continuous faces may be determined, e.g., based on the frame packing information. A padding sample location on the determined closest face may be derived. A padding sampie value at the derived padding sample location may be determined. In examples, a padding sampie value at the derived padding sampie location may be determined based on one or more pixel values associated with the padding sample location. In examples, a padding sample value at the derived padding sampie location may be determined based on interpolating the one or more pixel values associated with the padding sampie location. The neighboring sampie location may be associated with the interpolated padding sampie value. The closest face to the identified sampie location may be determined by having the smallest distance between a padding sample location and the discontinuous edge of the group of continuous faces. The padding sampie location on the determined closest face may be derived based on at least one of continuity characteristics of the 360- degree video content, a projection geometry, the frame packing information, and/or the like.

[0008] if the neighboring sampie location is not located outside of the discontinuous edge, geometry padding on the identified sample location may be skipped.

[0009] The frame-packed picture may include groups of one or more (e.g., multiple) continuous faces. Each group of continuous faces may include spatially neighboring faces, e.g., based on continuity characteristics of the 360-degree video content. Group of continuous faces may include a face row having one or more continuous faces. The group of continuous faces may be padded with one or more samples located in a padding zone. For example, the padding zone may be referred to a face row extension. Another group of continuous faces may be padded with a separate face row extension.

[0010] The frame packing information may be associated with at least one of a cube-based projection geometry, an octahedron projection geometry, a cylinder projection geometry, and/or the like. In examples, a cube-based projection geometry may include a cubemap projection, an equiangular cubemap (EAC), hybrid equiangular cubemap (HEC), and/or the like.

[0011] An indication for a padding size may be received. The padding size may include a vertical direction padding size and a horizontal direction padding size. A padded region (e.g., valid padded region) may be determined based on the received indication for the padding size. The neighboring sample location in the padded region (e.g., valid padded region) may be identified.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1A illustrates an example spherical sampling in longitude and latitude.

[0013] FIG. 1 B illustrates an example two-dimensional (2D) planar with equirectangular projection (ERP).

[0014] FIG. 2A illustrates an example three-dimensional (3D) geometric structure.

[0015] FIG. 2B illustrates an example 2D planer for six faces.

[0016] FIG. 3A illustrates an example picture with padded boundaries using ERP.

[0017] FIG. 3B illustrates an example picture with padded boundaries using cubemap projection (CMP).

[0018] FIG. 4A illustrates an example padding geometry for ERP.

[0019] FIG. 4B illustrates an example padded ERP picture.

[0020] FIG. 5A illustrates an example padding geometry for CMP.

[0021] FIG, 5B illustrates example padded CMP faces.

[0022] FIG. 6 illustrates an example 360-degree video workflow.

[0023] FIG. 7 illustrates an example video encoder.

[0024] FIG. 8 illustrates an example video decoder.

[0025] FIG, 9 illustrates an example reference sample used in intra prediction.

[0026] FIG. 10 illustrates an example indication of intra prediction directions.

[0027] FIG. 11 illustrates an example of inter prediction with a motion vector.

[0028] FIG. 12 illustrates an example padding for reference samples outside a picture boundary.

[0029] FIG, 13 illustrates an example of motion vector clipping,

[0030] FIG. 14 illustrates an example of spatial neighbors used in determining spatial merge candidates.

[0031] FIG. 15A illustrates an example group ef faces based geometry padding in a 3x2 frame packed picture. [0032] FIG, 15B illustrates an example group ef faces based geometry padding in a padded picture.

[0033] FIG. 18 illustrates an example of coding unit based motion vector clipping.

[0034] FIG. 17A is a system diagram of an example communications system in which one or more disclosed embodiments may be implemented.

[0035] FIG. 17B is a system diagram of an example wireless transmit/receive unit (VVTRU) that may be used within the communications system illustrated in FIG. 17A.

[0036] FIG. 17C is a system diagram of an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 17A.

[0037] FIG. 17D is a system diagram of further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 17A.

DETAILED DESCRIPTION

[0038] A detailed description of illustrative embodiments will now be described with reference to the various figures. Although this description provides a detailed example of possible implementations, it should be noted that the details are intended to be exemplary and in no way limit the scope of the application.

[0039] 360-degree videos described herein may include spherical videos, omnidirectional videos, virtual reality (VR) videos, panorama videos, immersive videos (e.g., light field videos that may include 6 degree of freedom), point cloud videos, and/or the like.

[0040] VR systems may use 360-degree video to provide the users the capability to view the scene from 360- degree angles in the horizontal direction and 180-degree angles in the vertical direction. VR and 360-degree video may be considered to be the direction for media consumption beyond Ultra High Definition (UHD) service. Work on the requirements and potential technologies for omnidirectional media application format may be performed to improve the quality of 360-degree video in VR and/or to standardize the processing chain for client's interoperability. Free view TV (FTV) may test the performance of one or more of the following: (1) 360- degree video (omnidirectionai video) based system; and/or (2) multi-view based system.

[0041] VR systems may include a processing chain. The processing chain may include capturing, processing, display, and/or applications. With respect to capturing, a VR system may use one or more cameras to capture scenes from different divergent views (e.g., 6 to 12 views). The views may be stitched together to form a 360-degree video in high resolution (e.g., 4K or 8K). On the client side and/or the user side, the virtual reality system may include a computation platform, head mounted display (HMD), and/or head tracking sensors. The computation platform may be in charge of receiving and/or decoding 360-degree video, and/or generating the viewport for display. Two pictures, one for each eye, may be rendered for the viewport. The two pictures may be displayed in HMD (e.g., for stereo viewing). The lens may be used to magnify the image displayed in HMD for better viewing. The head tracking sensor may keep (e.g., constantly keep) track of the viewers head orientation, and/or may feed the orientation information to the system to display the viewport picture for that orientation.

[0042] A VR system(s) may provide a touch device for a viewer to interact with objects in the virtual world. VR systems may be driven by a workstation with GPU support. A VR system may use a smartphone as a computation platform, a HMD display, and/or a head tracking sensor. The spatial HMD resolution may be 2160x1200, refresh rate may be 90Hz, and/or the field of view (FOV) may be 110 degrees. The sampling density for head tracking sensor may be 1000Hz, which may capture fast movement, A VR system may include a lens and/or cardboard, and/or may be driven by smartphone.

[0043] 360-degree videos may be compressed and/or delivered, for example, using dynamic adaptive streaming over HTTP (DASH)-based video streaming techniques. 360-degree video delivery may be implemented, for example, using a spherical geometry structure to represent 360-degree information. For example, the synchronized multiple views captured by the multiple cameras may be stitched on the sphere (e.g., as an integral structure). The sphere information may be projected onto 2D planar surface via geometry conversion (e.g., equirectanguiar projection and/or cubemap projection).

[0044] Equirectanguiar projection may be performed. FIG. 1 A shows an example sphere sampling in longitudes (φ) and latitudes (Θ), FIG. 1 B shows an example sphere being projected onto a 2D plane using ERP. The longitude φ in the range [-π, π] may be referred to as yaw, and the latitude Θ in the range [-π/2, π/2] may be referred to as pitch in aviation, π may be the ratio of a circle's circumference to its diameter.

Coordinates (x, y, z) may represent a point's coordinates in a 3D space. Coordinates (ue, ve) may represent a point's coordinates in a 2D plane after ERP. ERP may be represented mathematically, for example, as shown in (1) and (2).

(1) ue = (φ/(2 * π) + 0.5) * W ve = (0.5 - θ/π) * H (2) W and H may be the width and height of the 2D planar picture. As seen in FIG. 1A, the point P, the cross point between longitude L4 and latitude A1 on the sphere, may be mapped to a unique point q in FIG. 1 B in the 2D plane using (1) and/or (2). Point q in the 2D plane shown in FIG. 1 B may be projected back to point P on the sphere shown in FIG. 1 A, for example via inverse projection. The field of view (FOV) in FIG. 1 B shows an example where the FOV in a sphere is mapped to a 2D plane with a viewing angle along the X axis at about 110 degrees. [0045] One or more 380-degree videos may be mapped to 2D videos. The mapped video may be encoded using a video codec (e.g., H.264 and/or HEVC) and/or may be delivered to a client At the client side, the equirectangular video may be decoded and/or rendered based on user's viewport (e.g., by projecting and/or displaying the portion belonging to FOV in an equirectangular picture onto a HMD). Spherical video may be transformed to a 2D planar picture for encoding with ERP. The characteristic of an equirectangular 2D picture may be different from a non-equirectangular 2D picture (e.g., rectilinear video). A top portion of a picture, which may correspond to a north pole, and a bottom portion of a picture, which may correspond to a south pole, may be stretched (e.g., when compared to a middle portion of the picture, which may correspond to an equator). The stretching may indicate that the equirectangular sampling in the 2D spatial domain may be uneven. A motion field in the 2D equirectangular picture may be complex along the temporal direction.

[0046] Cubemap projection may be performed. The top and bottom portions of an ERP picture, which may correspond to a north and south pole respectively, may be stretched (e.g., when compared to the middle portion of the picture). This may indicate that the spherical sampling density of the picture may be uneven. A motion field, which may describe the temporal correlation among neighboring ERP pictures, may become complicated. Certain video codecs (e.g., MPEG-2, H.264, and/or HEVC) may use a transiationai model to describe the motion field and may not be able to represent shape varying movements in planar ERP pictures.

[0047] Geometric projection formats may be used to map 380-degree video onto multiple faces. For example, a cubemap projection (CMP) may be used. FIG. 2A illustrates an example CMP geometry. As seen in FIG. 2A, the CMP may include six square faces, which may be labeled as PX, PY, PZ, NX, NY, and/or NZ. P may stand for positive, and N may stand for negative. X, Y, and Z may refer to the axes. The faces may be labeled using numbers 0-5, e.g., PX (0), NX (1), PY (2), NY (3), PZ (4), NZ (5). if the radius of the tangent sphere is 1 , the lateral length of each face may be 2. The six faces of the CMP format may be packed together into a picture (e.g., a single picture). A face may be rotated by a degree (e.g., certain degree), which may affect (e.g., maximize affect) the continuity between neighboring faces. FIG. 2B illustrates an example packing that places six faces into a rectangular picture. A face index may be put in a direction that is aligned with a corresponding rotation of the face. For example, face #3 and #1 may be rotated counter-clockwise by 270 and 180 degrees, respectively. The other faces may not be rotated. As seen in FIG. 2B, a top row of 3 faces may be spatially neighboring faces in a 3D geometry and may have a continuous texture. As seen in FIG. 2B, a bottom row of 3 faces may be spatially neighboring faces in a 3D geometry and may have a continuous texture. The top face row and the bottom face row may not be spatially continuous in the 3D geometry, and a seam (e.g., a discontinuous boundary) may exist between the two face rows. [0048] in CMP, if the sampling density is 1 at the center of a face (e.g., each face), the sampling density may increase towards the edges. The texture around the edges may be stretched when compared to the texture at the center. Cubemap-based projections (e.g., equi-angular cubemap projection (EAC), adjusted cubemap projection (ACP), and/or the like) may adjust a face (e.g., each face) using a non-linear warping function in the vertical and/or horizontal directions. In EAC, for example, adjustments may be performed using a tangent function, in ACP, adjustment may be performed using a second order polynomial function.

[0049] Hybrid cubemap projection (HCP) may be performed, in HCP, an adjustment function and its parameters may be t ned for a face (e.g., each face) and/or a direction (e.g., each direction) individually. Cube-based projections may be packed. For example, cube-based projections may be packed similar to CMP. Face discontinuity within a frame packed picture may occur in a cube-based projection.

[0050] Geometry padding for 360-degree video coding may be performed.

[0051] Video codecs may consider 2D video captured on a plane. If motion compensated prediction uses a sampie(s) outside of a reference picture's boundaries, padding may be performed by copying the sample values from the picture boundaries. This type of padding may be known as repetitive padding. FIGs. 3A and 3B illustrate examples of extending an original picture (bounded by the dotted box) using repetitive padding for ERP and CMP, respectively.

[0052] A 380-degree video may encompass video information on a sphere (e.g., whole sphere), and/or may have a cyclic property. A reference picture of the 360-degree video may not have boundaries. For example, the reference picture of the 360-degree video may be wrapped around the sphere (e.g., and may not have boundaries). The cyclic property may exist when representing a 360-degree video on a 2D plane. The cyclic property may exist regardless of which projection format and/or which frame packing implementation may be used. Geometry padding may be performed for 360-degree video coding by padding a sample by considering the 3D geometry.

[0053] Geometry padding for ERP may be performed. ERP may be defined on a sphere with longitude and latitude. Given a point (u, v) to be padded (e.g., outside of the ERP picture), the point (u^!, ') may be used to derive a padding sample. This may be determined by:

if (u < 0 or u≥ W and (0 < v < H); ' = u%W, v' = v (3)

Otherwise, if (v < 0); v^! v - 1, (4)

Otherise, if (v≥ H); v^! = 2 * H— 1— v (5)

W and H may be the width and height of an ERP picture. [0054] FIG, 4A illustrates an example of geometry padding for ERP. Padding may be performed outside of a left boundary of a picture. For example, as seen in FIG 4A, samples A, B, and C may be padded with samples A', B^!, and C, which may be located inside the right boundary of the picture. Padding may be performed outside of a right boundary of a picture. For example, as seen in FIG 4A, samples D, E, and F may be padded with samples D', E', and F', which may be located inside the left boundary of the picture. Padding may be performed outside of a top boundary of a picture. For example, as seen in FIG. 4A, samples G, H, I, and J may be padded with samples G', H', I', and J', which may be located inside the top boundary of the picture with an offset of half the width. Padding may be performed outside a bottom boundary of a picture. For example, as seen in FIG, 4A, samples K, L, M, and N may be padded with samples K^!, U, M', and NT, which may be located inside the bottom boundary of the picture with an offset of half the width. FIG. 4B shows an example of an extended ERP picture using geometry padding. As seen in FIG. 4B, geometry padding may provide continuity between neighboring samples for areas outside of an ERP picture's boundaries.

[0055] When a coded picture is in CMP format, one or more faces of the CMP may be padded using geometry padding. FIG. 5A illustrates an example of geometry padding performed on a given face in a 3D geometry. As seen in FIG. 5A, a point P may be on face F1 and may be outside ef face F1 's boundaries. Point P may be padded. As seen in FIG. 5A, point O may be on the center of a sphere. As seen in FIG. 5A, R may be a left boundary point, which may be closest to P and inside face F1. As seen in FIG, 5A, point Q may be the projection point of point P on face F2 from the center point O. Geometry padding may be performed using a sample value at point Q to fill a sample value at point P. FIG. 5B illustrates an example of extended faces using geometry padding for a CMP 3x2 picture. As shown in FIG. SB, padding may be performed on each face individually. Geometry padding may provide samples for areas outside of a CMP face's boundary.

[0058] Hybrid video encoding may be performed. An example 360-degree video delivery implementation is illustrated in FIG. 6. As seen in FIG. 6, an exemplary 360-degree video delivery implementation may include a 360-degree video capture, which may use multiple cameras to capture videos covering a sphere space (e.g., whole sphere space). The videos may be stitched together in a native geometry structure. For example, the videos may be stitched together in an ERP format The native geometry structure may be converted to one or more projection formats for encoding, e.g., based on the video codecs. At the receiver, the video may be decoded, and/or the decompressed video may be converted to the geometry for display. The video may be used for rendering via viewport projection according to user's viewing angle.

[0057] FIG, 7 illustrates an example block-based hybrid video encoding system 600. The input video signal 602 may be processed block by block. Extended block sizes (e.g., referred to as a coding unit or CU) may be used (e.g., used in HEVC) to compress high resolution (e.g., 1080p and/or beyond) video signals. A CU may have up to 64x64 pixels (e.g., in HEVC). A CU may be partitioned into prediction units or PUs, for which separate predictions may be applied. For an input video block (e.g., a macrobiock (MB) or CU), spatial prediction 660 or motion prediction 662 may be performed. Spatial prediction (e.g., or intra prediction) may use pixels from already coded neighboring blocks in the same video picture and/or slice to predict a current video block. Spatial prediction may reduce spatial redundancy inherent in the video signal. Motion prediction (e.g., referred to as inter prediction or temporal prediction) may use pixels from already coded video pictures to predict a current video block. Motion prediction may reduce temporal redundancy inherent in the video signal. A motion prediction signal for a given video block may be signaled by a motion vector that indicates the amount and/or direction of motion between the current block and its reference block, if multiple reference pictures are supported (e.g., in H.264/AVC, HEVC, and/or the like), the reference picture index of a video block may be signaled to a decoder. The reference index may be used to identify from which reference picture in a reference picture store 664 the temporal prediction signal may come.

[0058] After spatial and/or motion prediction, a mode decision 680 in the encoder may select a prediction mode, for example based on a rate-distortion optimization. The prediction block may be subtracted from the current video block at 616. Prediction residuals may be de-correlated using a transform module 604 and a quantization module 606 to achieve a target bit-rate. The quantized residual coefficients may be inverse quantized at 610 and inverse transformed at 612 to form reconstructed residuals. The reconstructed residuals may be added back to the prediction block at 626 to form a reconstructed video block. An in-loop filter such as a de-blocking filter and/or an adaptive loop filter may be applied to the reconstructed video block at 666 before it is put in the reference picture store 664. Reference pictures in the reference picture store 664 may be used to code future video blocks. An output video bit-stream 620 may be formed. Coding mode (e.g., infer or intra coding mode), prediction mode information, motion information, and/or quantized residual coefficients may be sent to an entropy coding unit 608 to be compressed and packed to form the bit-stream 620.

[0059] FIG. 8 illustrates an example block-based video decoder. A video bit-stream 202 may be received, unpacked, and/or entropy decoded at an entropy decoding unit 208. Coding mode and/or prediction information may be sent to a spatial prediction unit 260 (e.g., if intra coded) and/or to a temporal prediction unit 262 (e.g., if inter coded). A prediction block may be formed the spatial prediction unit 260 and/or temporal prediction unit 262. Residual transform coefficients may be sent to an inverse quantization unit 210 and an inverse transform unit 212 to reconstruct a residual block. The prediction block and residual block may be added at 226. The reconstructed block may go through in-loop filtering 266 and may be stored in a reference picture store 264. Reconstructed videos in the reference picture store 264 may be used to drive a display device and/or to predict future video blocks. [0060] A video codec(s), such as H.264 and/or HEVC, may be used to code a 2D planar rectilinear video(s). Video coding may exploit spatial and/or temporal correlation (s), e.g., to remove information redundancies. One or more prediction techniques, such as intra prediction and/or inter prediction, may be applied during video coding, intra prediction may predict a sample value with its neighboring reconstructed samples. FIG. 9 shows example reference samples that may be used to intra-predict a current transform unit (TU). The reference samples may include reconstructed samples located above and/or to the left of the current TU. The reference samples may be from left and/or top neighboring reconstructed samples.

[0081] FIG. 10 illustrates an example indication of intra prediction directions in HEVC. For example, HEVC may specify 35 intra prediction modes that include planar (0), DC (1), and/or angular predictions (2-34), as shown in FIG. 10. An appropriate intra prediction mode may be selected. For example, an appropriate intra prediction mode may be selected at the encoder side. Predictions generated by multiple candidate intra prediction modes may be compared. The candidate intra prediction mode that produces the smallest distortion between prediction samples and original samples may be selected. The selected intra prediction mode may be coded into a bitstream.

[0082] Angular predictions may be used to predict directional textures. FIG. 1 1 shows an example inter prediction with a motion vector (MV). Blocks B0' and B1' in a reference picture may be respective reference blocks for blocks B0 and B1 of a current picture. Reference block BO' may be partially outside the boundary of the reference picture. Padding may be used to fill unknown samples outside picture boundaries. FIG. 12 shows an example padding for reference samples outside the picture boundary. For example, the padding examples for block B0' may have four parts P0, P1 , P2, and P3. Parts P0, P1 , and P2 may be outside the picture boundary and may be filled, for example, via padding. For example, part P0 may be filled with a top-left sample of the reference picture. Part P1 may be filled with vertical padding using a top-most row of the reference picture. Part P2 may be filled with horizontal padding using a left-most column of the picture.

[0083] A motion vector may be clipped, for example, such that a coding tree unit (CTU) (e.g., at most a CTU) may extend outside of the picture area plus some additional offset for filtering operations. The CTU may be a large coding unit (e.g., largest coding unit). For example, the horizontal component of the CU motion vector may be clipped between MV™ⁿ and MK^max by:

M¾^liax - W[_mg + W_pad - o - x_CTU - W_CJ[} - 1 (6)

M ^ⁿ = -i ad + o - cTU + l (7) W- and W_CT|j may be the image and CTU widths, respectively, o may be an offset for filtering operations. W_Dad may be the size of the horizontal padding, which may be set to I ¾_TU + 2o, x_CTU may be the horizontal coordinate of the top-left corner of the CTU that includes the current CU within the picture. FIG. 13 illustrates an example of horizontal motion vector clipping at a left picture boundary, e.g., MV™^m. MV clippings may be performed on the vertical component of a MV.

[0084] Motion vector clipping may be performed to restrict motion vectors within a range (e.g., given range). Motion vector prediction and/or a merge mode may be used for inter coding.

[0085] Motion vector prediction may use the motion vectors of a neighboring PU(s) and/or a temporally collocated PU(s) as a current MV's predictor. An encoder and/or a decoder may create a motion vector predictor candidate list. The list may be created using the motion vectors of neighboring PU(s) and/or a temporally collocated PUfs). An index of a selected MV predictor from the candidate list may be coded and signaled to the decoder. The decoder may construct a MV predictor list. The entry of the index signaled to the decoder may be used as a predictor of a PU's MV (current PU's MV).

[0068] A merge mode may use (e.g., reuse) the MV information of spatial and/or temporally neighboring PUs. The motion vectors for a PU (e.g., a current PU) may not be coded. An encoder and/or a decoder may form a motion vector merge candidate list. For example, the list may be created using the MV information of spatial and/or temporally neighboring PUs. FIG. 14 illustrates an example of the spatial neighbors (e.g., bottom left, left, top right, top, and/or top left) used for merge candidate derivation. A selected merge candidate index may be coded and/or signaled. A merge candidate list may be constructed by the decoder. The list construction by the decoder may be similar to (e.g., the same as) the list construction by the encoder. The entry of the signaled merge candidate index may be used as the MV of a PU (e.g., current PU).

[0087] Geometry padding may be used to pad a face of a coding geometry. Geometry padding may be performed individually. For example, the geometry padding may be performed for each face or each face boundary individually. An encoder may test different block sizes, prediction modes, motion vectors, and/or the like. At the encoder, an inter-coded picture may be padded. For example, an inter-coded picture may first be padded. Padding the inter-coded picture may occur before performing prediction. Geometries may be composed of more than one faces. The padding size in geometry padding may be similar (e.g., identical) to the padding size in other padding implementations. If the padding size is identical, geometry padding may use additional memory. For example, a cube-based geometry (e.g., CMP, ACP, EAG, and/or the like), may be packed in a 3x2 configuration with a face size F and padding size S. The memory used for a luma component of an inter-coded picture (e.g., each inter coded picture) for padding may be 10*FXS-H XS². The memory used for geometry padding may be 24xFxS+24xS².

[0088] Geometry padding may be performed near a frame packed picture's boundaries and/or near the boundaries between discontinuous faces. Face-based geometry padding may be skipped near the boundaries between continuous face. A group of continuous faces in a frame packed picture may be padded (e.g., jointly padded as a whole). Padding a group of continuous faces in a frame packed picture may be performed using an implementation similar to geometry padding. For example, top and bottom face rows shown in FIG. 15A may be padded as two groups of three faces each as illustrated in FIG. 15B. Padding may be skipped on a face (e.g., each face individually), as seen in FIG. 5B. The memory used for padding described herein may be

[0089] Padding may constrain a CU, using, for example, motion vector clipping, to its CTU position, A CU may skip translating to cover a padded area (e.g., the whole padded area). 2D padding may repeat samples in a padded area, A CU, for example, may be translated to cover the whole padded area.

[0070] Geometry padding for 380-degree video coding may be performed by padding a group of continuous faces. A group of faces may be padded. For example, a group of faces may be padded jointly. Padding may be skipped at the boundaries between continuous faces. Motion vector clipping may be performed based on coding unit (CU) positions. For example, motion vector clipping may be performed based on the CU coordinates within a face and/or a group of continuous faces. A CU translation may cover a padded area (e.g., the whole padded area). Geometry padding may pad one or more sample pixels located at and/or near a boundary of a group of continuous faces.

[0071] A group of continuous faces in a frame packed picture may be padded (e.g., jointly padded) using geometry padding. For example, as seen in FIG. 15A, a frame packed picture may be composed of two sets of continuous faces (e.g., a top row and a bottom row). As seen in FIG. 15A, a set of continuous faces (e.g., the top face row and the bottom face row) may be composed of three faces. FIG. 15B illustrates an example padded picture where the top and bottom face rows are padded considering a group of continuous faces. Face columns may be grouped together and padded accordingly.

[0072] Boundaries between continuous faces may not be padded when jointly padding a group of continuous faces in a frame-packed picture. The group of continuous faces in the frame-packed picture may be identified based on frame packing information associated with the frame-packed picture. In examples, the group of continuous faces may include a first group of continuous faces and a second group of continuous faces. Each group of continuous faces may include one or more spatially neighboring faces that are based on continuity characteristics of the 360-degree video content. The first continuous face may include a face row having one or more continuous faces. The second continuous faces may include a face row having one or more continuous faces, A sample location located in the group of continuous faces may be identified,

[0073] One or more boundaries of the group of faces (e.g., the outer boundaries of the group of faces) may be padded. Whether a neighboring sample location associated with the identified sample location is located outside of a discontinuous edge of the group of continuous faces may be determined. In examples, if the identified sample location is at a first face boundary of a face in the group of continuous faces, whether content across the first face boundary is continuous may be determined, e.g., based on the frame packing information. Based on a determination that the content across the first face boundary is continuous, it may be determined that the neighboring sample location associated with the identified sample location is not located outside of a discontinuous edge of the group of continuous faces. Based on a determination that the content across the first face boundary is discontinuous, the first face boundary may be tagged as a discontinuous edge. Whether the neighboring sample location associated with the identified sample location is located outside of the first face boundary may be determined.

[0074] if the neighboring sample location is located outside of the discontinuous edge of the group of continuous faces, geometry padding may be performed on the identified sample location. A padded sample value may be obtained from a sample position in the padded region. For example, the padded sample value may be obtained, in examples, geometry padding may be performed by one or more of the following. The closest face to the identified sample location located outside of the discontinuous edge of the group of continuous faces may be determined, e.g., based on at least one continuity characteristics of the 360-degree video content, a projection geometry, the frame packing information, and/or the like. A padding sample location on the determined closest face may be derived. A padding sample value at the derived padding sample location may be determined. In examples, a padding sample value at the derived padding sample location may be determined based on one or more pixel values associated with the padding sample location. In examples, a padding sample value at the derived padding sample location may be determined based on interpolating the one or more pixel values associated with the padding sample location. The closest face to the identified sample location may be determined if a padding sample location and the discontinuous edge of the group of continuous faces have the smallest distance. The padding sample location on the determined closest face may be derived based on at least one of continuity characteristics of the 380-degree video content, a projection geometry, or the frame packing information.

[0075] Geometry padding based on a group of continuous faces, as described herein, may use reduced memory for padded samples. The memory used for padded samples may be higher if, for example, the same padding size is used in each direction. Horizontal and/or vertical padding sizes may be reduced when performing geometry padding based on a group continuous faces. For example, a cube-based geometry (e.g., CMP, ACP, and/or EAC) may be packed in a 3x2 configuration, with a face size F and padding size S in the horizontal and vertical directions. The memory used for a iuma component of an inter-coded picture (e.g., each inter-coded picture) may be 1 G*FxS+4xS². If, for exampie, geometry padding based on a group of continuous faces is performed, the memory used may be 16xFxS+6xS². The padding size S may be reduced to 5 by:

[0076] The vertical padding size may be reduced. For example, the vertical padding size may be reduced by two. The horizontal padding size may be maintained (e.g., may not change).

[0077] Geometry padding based on a group of continuous faces, as described herein, may be performed on a group of continuous faces (e.g., any group of continuous faces) in a frame packed picture. Padding may be performed. For example, padding may be performed for various face shapes and/or various group shapes. The face shape and/or size may be signaled. For example, the face shape and/or size may be signaled via a bitstream. The group shape, position, and/or size may be signaled. For example, the group shape, position, and/or size may be signaled via a bitstream.

[0078] A padded size S (e.g., padding size) may be signaled. The padded size S may include a padded size for horizontal direction and/or a padded size for vertical direction. For exampie, a padded size S for the horizontal and/or vertical directions may be signaled separately. A padded size S for the horizontal and/or vertical directions may be signaled in a sequence level. For example, a padded size S for the horizontal and/or vertical directions may be signaled in sequence parameter sets. The signaled padded size S for the horizontal and/or vertical directions at the sequence parameter sets may be used in decoding a bitstream. The signaled padding size may be used in the decoding process to clip a motion vector. For example, the padding size may be used to clip a motion vector such that the corresponding reference block may be located within the padded region (e.g., padded group).

[0079] A padding size may be included in an indication. As described herein, the padding size may include a vertical direction padding size and/or a horizontal direction padding size. A valid padded region may be determined based on the indication for the padding size. A neighboring sample location in the valid padded region may be identified.

[0080] A neighboring sample location may be outside or partially outside of the valid padded region. In examples, a hybrid padding may be performed to pad the neighboring sample location that is outside or partially outside of the valid padded region. For example, the hybrid padding may apply geometry padding and repetitive padding, if the position of the neighboring sample is located within the valid region, the geometry padding may be applied as described herein (e.g., based on the 3D geometry structure represented in a 380- degree video). If the position of the neighboring sample is not within the valid padded region or partially outside of the valid padded region, repetitive padding may be applied to pad the sample by clipping the sample position to the nearest position that is within the valid padded region horizontally and/or vertically.

[0081] Face size and/or shape may be derived based on frame packing and/or projection format information. Group size and/or shape may be derived based on frame packing and/or projection format information.

[0082] When using geometry padding, a CU motion vector may be constrained. For example, a CU may skip being translated outside of a padded face to which the CU belongs. CU based motion vector clipping may be performed. For example, one or more CU's coordinates may be used to clip the motion vector within a padded face. For example, the horizontal component of the CU motion vector may be clipped between MV^^m and M¾^rax by:

MVJT = fece + Wpad - - cu - ^CU ^

Wface ^and W½ ^maY be the face width and CU width, respectively. W_pad may be the horizontal padding size, o may be an offset for filtering operations. x_CLi may be the horizontal coordinate of the top-left corner of the current CU within the face. FIG. 16 illustrates an example of horizontal motion vector clipping at a left face boundary, e.g., MV™ⁿ.

[0083] The vertical component of a CU motion vector may be clipped between Ml/™" and l^^max by:

MV - / to + //pad - o - y_cu - //_cu (11 )

= --//c c ÷ ~ y_;;J (12) face and Hcu may be the face height and CU height, respectively. _pad may be the vertical padding size, o may be an offset for filtering operations. y_cu may be the vertical coordinate of the top-left corner of the current CU within the face.

[0084] A CU may be translated to cover a padded face (e.g., whole padded face) if the CU coordinates are used for translation.

[0085] As seen in (9) - (12), face-based geometry padding may be performed, if, for example, geometry padding based on a group of continuous faces is performed, motion vector clipping may consider the face group size and/or the CU coordinates within the group of faces, in the geometry padding implementation described herein, W_facein (9) may be replaced by W_qmuo, where W_Qmup may be the width of the group ef faces, to calculate ¾.^e, f/_face in (11) may be replaced by _group, where _group may be the height of the group of faces, to calculate

[0088] CU-based motion vector clipping may be applied. For example, CU based motion vector clipping may be applied considering a coded picture size and/or GU coordinates within a coded picture,

[0087] i examples, the CU based motion vector clipping techniques described herein may be applied to one or more other motion models (e.g., affine motion models), in examples, the techniques described herein may be applied to the derived motion vectors in an inter merge mode.

[0088] As used herein, 360-degree videos may include omni-directional videos, spherical videos, six degree of freedom (6DoF) media, monoscopic and stereoscopic (3D) virtual reality videos, and/or the like.

[0089] FIG. 17A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMG), and the like.

[0090] As shown in FIG, 17A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104/113, a CN 106/115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of VVTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and/or a "STA," may be configured to transmit and/or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hoispot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE. [0091] The communications systems 100 may also include a base station 114a and/or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the GN 106/115, the Internet 110, and/or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

[0092] The base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into ceil sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, e.g., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (Ml MO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and/or receive signals in desired spatial directions.

[0093] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT),

[0094] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115/116/117 using wideband CDMA (WCDMA).

WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet Access (HSUPA), [0095] in an embodiment the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 1 16 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).

[0096] I n an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as MR Radio Access, which may establish the air interface 1 16 using New Radio (NR).

[0097] in an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., an eNB and a gNB).

[0098] in other embodiments, the base station 1 14a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.1 1 (e.g., Wireless Fidelity (WiFi), IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, interim Standard 2000 (IS- 2000), Interim Standard 95 (IS-95), interim Standard 856 (!S-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like,

[0099] The base station 114b in FIG. 17A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like, in one embodiment, the base station 1 14b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.1 1 to establish a wireless local area network (WLAN). in an embodiment, the base station 1 14b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 1 14b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picoceil or femtoceil. As shown in FIG. 17A, the base station 1 14b may have a direct connection to the Internet 1 10, Thus, the base station 114b may not be required to access the Internet 1 10 via the CN 106/1 15.

[0100] The RAN 104/1 13 may be in communication with the CN 106/115, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106/1 15 may provide call control, billing services, mobile location-based services, pre-paid calling, internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 17A, it will be appreciated that the RAN 104/113 and/or the CM 106/115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/113 or a different RAT. For example, in addition to being connected to the RAN 104/113, which may be utilizing a NR radio technology, the CN 106/115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology,

[0101] The CN 108/115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or the other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and/or the internet protocol (IP) in the TCP/IP internet protocol suite. The networks 112 may include wired and/or wireless communications networks owned and/or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104/113 or a different RAT.

[0102] Some or ail of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 17A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0103] FIG, 17B is a system diagram illustrating an example WTRU 102, As shown in FIG, 17B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 128, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and/or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0104] The processor 118 may be a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG. 17B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0105] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 118, For example, in one embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals, in an embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example, in yet another embodiment, the transmit/receive element 122 may be configured to transmit and/or receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0106] Although the transmit/receive element 122 is depicted in FIG. 17B as a single element the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0107] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the VVTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0108] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. in addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like, in other embodiments, the processor 118 may access information from, and store data in, memory that is not physicaily located on the WTRU 102, such as on a server or a home computer (not shown). [0109] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 1 G2, For example, the power source 134 may include one or more dry ceil batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0110] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 118 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations, it will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment

[0111] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and/or Augmented Reality (VR/AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hail effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.

[0112] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or ail of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception). [0113] FIG, 17C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0114] The RAN 104 may include eNode~Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a.

[0115] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, and the like. As shown in FIG. 17C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0116] The CN 106 shown in FIG. 17C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0117] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and/or WCDMA.

[0118] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0119] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. [0120] The CN 108 may facilitate communications with other networks. For example, the CN 106 may provide the WT Us 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 108 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 108 and the PSTN 108, In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers [0121] Although the WTRU is described in FIGs. 17A-17D as a wireless terminal, if is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0122] i representative embodiments, the other network 112 may be a WLAN.

[0123] A WLAN in infrastructure Basic Serace Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic in to and/or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs withi a BSS may be considered and/or referred to as peer-to-peer traffic. The peer- to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). in certain representative embodiments, the DLS may use an 802.11e DLS or an 802,11 z tunneled DLS (TDLS). A WLAN using an Independent BSS (I BSS) mode may not have an AP, and the STAs (e.g., ail of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication,

[0124] When using the 802.11 ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP, in certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) may be implemented, for example in in 802.11 systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed/detected and/or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0125] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0126] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two noncontiguous 80 MHz channels, which may be referred to as an 80-+-80 configuration. For the 80+80

configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0127] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802,11 af and 802.11 ah relative to those used in 802.11 η, and 802.11ac. 802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 18 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control/Machine- Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0128] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11ac, 802.11 af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and/or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode, in the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 18 MHz, and/or other channel bandwidth operating modes. Carrier sensing and/or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0129] i the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916,5 MHz to 927.5 MHz, The total bandwidth available for 802.11 ah is 6 MHz to 28 MHz depending on the country code.

[0130] FIG. 17D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0131] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and/or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum, in an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180c),

[0132] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TT!s) of various or scalable lengths (e.g., containing varying number of OFDM symbols and/or lasting varying lengths of absolute time).

[0133] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and/or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). in the standalone configuration, VVTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a, 180b, 180c while also communicating with/connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode~Bs 160a, 160b, 160c substantially simultaneously. In the non- standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and/or throughput for servicing WTRUs 102a, 102b, 102c.

[0134] Each of the gNBs 180a, 180b, 180c may be associated with a particular ceil (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 17D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0135] The CN 115 shown in FIG. 17D may include at least one AMF 182a, 182b, at least one UPF

184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0138] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLG) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and/or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as WiFi.

[0137] The SMF 183a, 183b may be connected to an A F 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0138] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0139] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0140] in view of FIGs. 17A-17D, and the corresponding description of FIGs. 17A-17D, one or more, or ail, of the functions described herein with regard to one or more of: WTRU 102a~d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and/or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and/or to simulate network and/or WTRU functions.

[0141] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or ail, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air wireless communications.

[0142] The one or more emulation devices may perform the one or more, including all, functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and/or a non-deployed (e.g., testing) wired and/or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment Direct RF coupling and/or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and/or receive data.

[0143] The processes and techniques described herein may be implemented in a computer program, software, and/or firmware incorporated in a computer-readable medium for execution by a computer and/or processor. Examples of computer-readable media include, but are not limited to, electronic signals

(transmitted over wired and/or wireless connections) and/or computer-readable storage media. Examples of computer-readable storage media include, but are not iimited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, but not iimited to, internal hard disks and removable disks, magneto-optical media, and/or optical media such as CD- ROM disks, and/or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNG, and/or any host computer

Claims

CLA! S What is Claimed:

1. A method of coding a 360-degree video content, the method comprising:

receiving a frame-packed picture for the 360-degree video content;

identifying a group of continuous faces in the frame-packed picture based on frame packing information for the frame-packed picture;

identifying a sample location in the group of continuous faces;

determining whether a neighboring sample location associated with the identified sample location is located outside of a discontinuous edge of the group of continuous faces;

on a condition that the neighboring sample location is located outside of the discontinuous edge of the group of continuous faces, performing geometry padding on the identified sample location; and

processing the 360-degree video content based on the geometry padding.

2. The method of claim 1 , wherein determining whether the neighboring sample location associated with the identified sample location is located outside of the discontinuous edge of the group of continuous faces further comprises:

upon determining that the identified sample location is at a first face boundary of a face in the group of continuous faces, determining whether content across the first face boundary is continuous based on the frame packing information;

based on a determination that the content across the first face boundary is continuous, determining that the neighboring sample location associated with the identified sample location is not located outside of a discontinuous edge of the group of continuous faces; and

based on a determination that the content across the first face boundary is discontinuous, tagging the first face boundary as a discontinuous edge, and further determining whether the neighboring sample location associated with the identified sample location is located outside of the first face boundary.

3. The method of claim 1 , wherein on a condition that the neighboring sample location is not located outside of the discontinuous edge, geometry padding on the identified sample location is skipped,

4. The method of claim 1 , wherein performing geometry padding comprises:

determining the closest face to the identified sample location located outside of the discontinuous edge of the group of continuous faces based on the frame packing information; deriving a padding sample location on the determined closest face;

determining a padding sample value at the derived padding sample location based on one or more pixel values associated with the padding sample location; and

associating the neighboring sample location with the determined padding sample value.

5. The method of claim 4, wherein the padding sample value is determined based on interpolating the one or more pixel values associated with the padding sample location.

6. The method of claim 4, wherein the closest face to the identified sample location is determined by having the smallest distance between a padding sample location and the discontinuous edge of the group of continuous faces.

7. The method of claim 4, wherein deriving the padding sample location on the determined closest face is based on at least one of continuity characteristics of the 380-degree video content, a projection geometry, or the frame packing information.

8. The method of claim 1 , wherein the frame-packed picture comprises a first group of continuous faces and a second group of continuous faces, and each group of continuous faces comprises spatially neighboring faces based on continuity characteristics of the 360-degree video content.

9. The method of claim 8, wherein the first group of continuous faces comprise a first face row having a first plurality of continuous faces, and the second group of continuous faces comprise a second face row having a second plurality of continuous faces.

10. The method of claim 8, wherein the first group of continuous faces is padded with a first face row extension, and the second group of continuous faces is padded with a second face row extension.

11. The method of claim 1, wherein the frame packing information is associated with at least one of a cubemap projection geometry, an octahedron projection geometry, or a cylinder projection geometry.

12. The method of claim 1, wherein the method further comprises: receiving an indication for a padding size, the padding size comprising a vertical direction padding size and a horizontal direction padding size;

determining a valid padded region based on the received indication for the padding size; and identifying the neighboring sample location in the valid padded region, wherein when the neighboring sample location is within the valid padded region, performing geometry padding using a sample within the valid padded region, and wherein when the neighboring sample location is outside of the valid padded region, performing repetitive padding using a sample at a boundary of the valid padded region,

13, A wireless transmit/receive unit (WTRU) for coding a 360-degree video content, the WTRU comprising: a processor configured to:

receive a frame-packed picture for the 360-degree video content;

identify a group of continuous faces in the frame-packed picture based on frame packing information for the frame-packed picture;

identify a sample location in the group of continuous faces;

determine whether a neighboring sample location associated with the identified sample location is located outside of a discontinuous edge of the group of continuous faces;

on a condition that the neighboring sample location is located outside of the discontinuous edge of the group of continuous faces, perform geometry padding on the identified sample location; and

process the 360-degree video content based on the geometry padding,

14, The WTRU of claim 13, wherein the processor for determining whether the neighboring sample location associated with the identified sample location is located outside of the discontinuous edge of the group of continuous faces is further configured to:

upon determining that the identified sample location is at a first face boundary of a face in the group of continuous faces, determine whether content across the first face boundary is continuous based on the frame packing information;

based on a determination that the content across the first face boundary is continuous, determine that the neighboring sample location associated with the identified sample location is not located outside of a discontinuous edge of the group of continuous faces; and based on a determination that the content across the first face boundary is discontinuous, tag the first face boundary as a discontinuous edge, and further determining whether the neighboring sample location associated with the identified sample location is located outside of the first face boundary.

15. The WTRU of claim 13, wherein on a condition that the neighboring sample location is not located outside of the discontinuous edge, the processor is configured to skip geometry padding on the identified sample location.

16. The WTRU of claim 13, wherein the processor for performing geometry padding is configured to: determine the closest face to the identified sample location located outside of the discontinuous edge of the group of continuous faces based on the frame packing information, wherein the closest face is identified by having the smallest distance between a padding sample location and the discontinuous edge of the group of continuous faces;

derive a padding sample location on the determined closest face;

determine a padding sample value at the derived padding sample location based on one or more pixel values associated with the padding sample location; and

associate the neighboring sample location with the determined padding sample value.

17. The WTRU of claim 16, wherein the processor is configured to determine the padding sample value based on interpolating the one or more pixel values associated with the padding sample location.

18. The WTRU of claim 13, wherein the frame-packed picture comprises a first group of continuous faces and a second group of continuous faces, and each group of continuous faces comprises spatially neighboring faces based on continuity of characteristics of the 360-degree video content.

19. The WTRU of claim 18, wherein the first group of continuous faces comprise a first face row having a first plurality of continuous faces, and the second group of continuous faces comprise a second face row having a second plurality of continuous faces.

20. The WTRU of claim 13, wherein the processor is further configured to:

receive an indication for a padding size, the padding size comprising a vertical direction padding size and a horizontal direction padding size; determine a valid padded region based on the received indication for the padding size; and identify the neighboring sample in the valid padded region, wherein when the neighboring sample location is within the valid padded region, perform geometry padding using a sample within the valid padded region, and wherein when the neighboring sample location is outside of the valid padded region, perform repetitive padding using a sample at a boundary of the valid padded region.