Patent ID: 11889060
Assignee: BYTEDANCE INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:
perform a conversion between a video comprising one or more pictures comprising one or more subpictures and a bitstream of the video,
wherein the bitstream conforms to a format rule that specifies that a subpicture cannot be a random access decodable leading subpicture or a random access skipped leading subpicture when the subpicture is not a leading subpicture of an intra random access point subpicture, and
wherein the leading subpicture precedes the intra random access point subpicture in output order,
wherein the intra random access point subpicture is a subpicture for which all video coding layer (VCL) network abstraction layer (NAL) units have a same value of NAL unit type in a range of IDR_W_RADL to CRA_NUT, inclusive,
wherein the random access decodable leading subpicture is a subpicture for which each VCL NAL unit has NAL unit type equal to RADL_NUT,
wherein the random access skipped leading subpicture is a subpicture for which each video coding layer (VCL) network abstraction layer (NAL) has NAL unit type equal to RADL_NUT,
wherein the format rule specifies an order by which pictures are indicated in the bitstream,
wherein when a current subpicture is a clean random access subpicture, the format rule disallows an entry in a reference picture list of a current slice from including a first picture that precedes, according to a first order, a second picture that precedes, according to a second order, a current picture,
wherein the second picture comprises an intra random access point subpicture having a same layer identifier of a network abstraction unit (NAL) unit and a same subpicture index as the current subpicture, and
wherein the clean random access subpicture is an intra random access point subpicture for which each VCL NAL unit has nal_unit_type equal to CRA_NUT.