US 11,778,220 B2
Constraints on signaling of video layers in coded bitstreams
Ye-kui Wang, San Diego, CA (US)
Assigned to BYTEDANCE INC., Los Angeles, CA (US)
Filed by Bytedance Inc., Los Angeles, CA (US)
Filed on Jun. 21, 2022, as Appl. No. 17/845,536.
Application 17/845,536 is a continuation of application No. PCT/US2020/067016, filed on Dec. 24, 2020.
Claims priority of provisional application 62/954,907, filed on Dec. 30, 2019.
Claims priority of provisional application 62/953,854, filed on Dec. 26, 2019.
Prior Publication US 2022/0337880 A1, Oct. 20, 2022
Int. Cl. H04N 19/105 (2014.01); H04N 19/46 (2014.01); H04N 19/70 (2014.01); H04N 19/187 (2014.01)
CPC H04N 19/70 (2014.11) [H04N 19/105 (2014.11); H04N 19/187 (2014.11); H04N 19/46 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A method of video processing, comprising:
performing a conversion between a video comprising a plurality of video layers and a bitstream of the video,
wherein the bitstream comprises a plurality of output layer sets (OLSs), each of which comprises one or more of the plurality of video layers, and the bitstream conforms to a format rule,
wherein the format rule specifies that, for a layer i, where i is an integer, the bitstream includes a set of first syntax elements which is used to derive a first variable indicating whether the layer i is used as an output layer in at least one of the plurality of OLSs,
wherein the format rule further specifies that the bitstream includes a set of third syntax elements which is used to derive a second variable indicating whether the layer i is used as a reference layer for at least one of the plurality of video layers, and wherein the format rule disallows values of the first variable and the second variable both equal to 0, and
wherein disallowing the values of the first variable and the second variable both equal to 0 indicates that no layer that is neither a direct reference layer of any other layer nor an output layer of at least one OLS.