Method for signaling virtual boundary signaling with subpictures in coded video stream
摘要
說(shuō)明書(shū)
For example, subpic_ctu_top_left_x[i] specifies horizontal position of top left CTU of i-th subpicture in unit of CtbSizeY. The length of the syntax element is Ceil(Log 2((pic_width_max_in_luma_samples+CtbSizeY?1)>>CtbLog2SizeY)) bits. When not present, the value of subpic_ctu_top_left_x[i] is inferred to be equal to 0. subpic_ctu_top_left_y[i] specifies vertical position of top left CTU of i-th subpicture in unit of CtbSizeY. The length of the syntax element is Ceil(Log 2((pic_height_max_in_luma_samples+CtbSizeY?1)>>CtbLog2SizeY))bits. When not present, the value of subpic_ctu_top_left_y[i] is inferred to be equal to 0. subpic_width_minus1[i] plus 1 specifies the width of the i-th subpicture in units of CtbSizeY. The length of the syntax element is Ceil(Log 2((pic_width_max_in_luma_samples+CtbSizeY?1)>>CtbLog2SizeY))bits. When not present, the value of subpic_width_minus1[i] is inferred to be equal to ((pic_width_max_in_luma_samples+CtbSizeY?1)>>CtbLog2SizeY)?subpic_ctu_top_lef t_x[i]?1. subpic_height_minus1[i] plus 1 specifies the height of the i-th subpicture in units of CtbSizeY. The length of the syntax element is Ceil(Log 2((pic_height_max_in_luma_samples+CtbSizeY?1)>>CtbLog2SizeY)) bits. When not present, the value of subpic_height_minus1[i] is inferred to be equal to ((pic_height_max_in_luma_samples+CtbSizeY?1)>>CtbLog2SizeY)?subpic_ctu_top_left_y[i]?1.
In the same or another embodiment, when the number of subpictures is greater than 1, subpic_info_present_flag may be equal to 1 and the subpicture partitioning information may be explicitly signaled in a parameter set, as shown in
