Patent ID: 11863794
Assignee: BYTEDANCE INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 19:
20. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:
generating the bitstream of the video comprising a video picture according to a format rule,
wherein the video picture comprises one or more tiles that form one or more tile rows and one or more tile columns,
wherein the bitstream conforms to a format rule,
wherein the format rule specifies that a tile row index is derived for each coding tree block (CTB) row of a tile of the video picture,
wherein the video picture also comprises one or more subpictures,
wherein each of the one or more subpictures comprises one or more slices that collectively form a rectangular subset of the video picture,
wherein the format rule further specifies that a height of a subpicture in units of tile rows is derived based on tile row indices of a top CTB and/or a bottom CTB included in the subpicture,
wherein a height of an i-th subpicture in units of tile rows, denoted as SubpicHeightInTiles[i], is derived as follows:
for(i=0; i<=sps_num_subpics_minus1; i++) {
topY=sps_subpic_ctu_top_lefty[i]
bottomY=topY+sps_subpic_height_minus1 [i]
SubpicHeightInTiles[i]=ctbToTileRowIdx[botY]+1−ctbToTileRowIdx[topY]

},
wherein sps_num_subpics_minus1 plus 1 represents a number of subpictures in the video picture,
wherein sps_subpic_ctu_top_lefty[i] represents a vertical position of a top-left CTB of the i-th subpicture,
wherein sps_subpic_height_minus1[i] plus 1 specifies the height of the i-th subpicture, and
wherein ctbToTileRowIdx[botY] and ctbToTileRowIdx[topY] represent the tile row indices of the bottom CTB and the top CTB, respectively, included in the subpicture.