Error mitigation for sublayers in video coding
A video coding mechanism is disclosed. The mechanism includes encoding a bitstream comprising a video parameter set (VPS) and one or more sublayers. A buffering period (BP) supplemental enhancement information (SEI) message comprising a BP maximum sublayers minus one (bp_max_sublayers_minus1) is also encoded into the bitstream. The bp_max_sublayers_minus1 is set to a value in a range of zero to a maximum number of sublayers indicated in the VPS. A hypothetical reference decoder (HRD) is initialized based on the BP SEI message. A set of bitstream conformance tests are performed on the sublayers. The bitstream is stored for communication toward a decoder.
1 . A non-transitory computer-readable storage medium storing a bitstream that, when parsed by a coding device, is used by the coding device to generate a video, the bitstream comprising:
a video parameter set (VPS), one or more sublayers, a buffering period (BP) maximum sublayers minus one (bp_max_sublayers_minus1) set to a value in a range of zero to a maximum number of sublayers specified by the VPS, and a hypothetical reference decoder (HRD) coded picture buffer count minus one (hrd_cpb_cnt_minus1), wherein the hrd_cpb_cnt_minus1 plus one specifies a number of alternative coded picture buffer (CPB) delivery schedules, and wherein a value of hrd_cpb_cnt_minus1 is constrained to a range from zero to thirty one, inclusive.
2 . The non-transitory computer-readable storage medium of claim 1 , wherein the bp_max_sublayers_minus1 is included in a buffering period (BP) supplemental enhancement information (SEI) message, and wherein the BP SEI message includes parameters associated with a maximum number of temporal sublayers specified by bp_max_sublayers_minus1.
3 . The non-transitory computer-readable storage medium of claim 2 , wherein the parameters in the BP SEI message include an initial coded picture buffer (CPB) removal delay and an initial CPB removal offset.
4 . The non-transitory computer-readable storage medium of claim 1 , wherein the maximum number of sublayers specified by the VPS is included in a VPS maximum sublayers minus one (vps_max_sublayers_minus1) plus one.
5 . The non-transitory computer-readable storage medium of claim 4 , wherein the vps_max_sublayers_minus1 is contained in the VPS.
6 . The non-transitory computer-readable storage medium of claim 2 , wherein the bitstream is configured to initialize a HRD at a position of an associated access unit (AU) in decoding order based on the BP SEI message.
7 . The non-transitory computer-readable storage medium of claim 1 , wherein the bitstream is a temporal scalable bitstream, wherein the one or more sublayers are temporal scalable layers of the bitstream, and wherein each sublayer includes video coding layer (VCL) network abstraction layer (NAL) units and associated non-VCL NAL units with a same value of a temporal identifier (TemporalId) variable.
8 . An encoder comprising:
a processor configured to:
encode a bitstream comprising a video parameter set (VPS) and one or more sublayers;
encode into the bitstream a buffering period (BP) supplemental enhancement information (SEI) message comprising a BP maximum sublayers minus one (bp_max_sublayers_minus1) set to a value in a range of zero to a maximum number of sublayers specified by the VPS, and a hypothetical reference decoder (HRD) coded picture buffer count minus one (hrd_cpb_cnt_minus1), wherein the hrd_cpb_cnt_minus1 plus one specifies a number of alternative coded picture buffer (CPB) delivery schedules, and wherein a value of hrd_cpb_cnt_minus1 is constrained to a range from zero to thirty one, inclusive;
initialize a HRD based on the BP SEI message; and
perform with the HRD a set of bitstream conformance tests on the sublayers.
9 . The encoder of claim 8 , wherein the BP SEI message includes parameters associated with a maximum number of temporal sublayers specified by bp_max_sublayers_minus1.
10 . The encoder of claim 9 , wherein the parameters in the BP SEI message include an initial coded picture buffer (CPB) removal delay and an initial CPB removal offset.
11 . The encoder of claim 8 , wherein the maximum number of sublayers specified by the VPS is included in a VPS maximum sublayers minus one (vps_max_sublayers_minus1) plus one.
12 . The encoder of claim 11 , wherein the vps_max_sublayers_minus1 is contained in the VPS.
13 . The encoder of claim 8 , wherein the HRD is initialized at a position of an associated access unit (AU) in decoding order based on the BP SEI message.
14 . The encoder of claim 8 , wherein the bitstream is a temporal scalable bitstream, wherein the one or more sublayers are temporal scalable layers of the bitstream, and wherein each sublayer includes video coding layer (VCL) network abstraction layer (NAL) units and associated non-VCL NAL units with a same value of a temporal identifier (TemporalId) variable.
15 . A non-transitory computer readable medium comprising a computer program product for use by a video coding device, the computer program product comprising computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to:
encode a bitstream comprising a video parameter set (VPS) and one or more sublayers;
encode into the bitstream a buffering period (BP) supplemental enhancement information (SEI) message comprising a BP maximum sublayers minus one (bp_max_sublayers_minus1) set to a value in a range of zero to a maximum number of sublayers specified by the VPS, and a hypothetical reference decoder (HRD) coded picture buffer count minus one (hrd_cpb_cnt_minus1), wherein the hrd_cpb_cnt_minus1 plus one specifies a number of alternative coded picture buffer (CPB) delivery schedules, and wherein a value of hrd_cpb_cnt_minus1 is constrained to a range from zero to thirty one, inclusive;
initialize a HRD based on the BP SEI message; and
perform with the HRD a set of bitstream conformance tests on the sublayers.
16 . The non-transitory computer readable medium of claim 15 , wherein the bp_max_sublayers_minus1 is included in a buffering period supplemental enhancement information (SEI) message, and wherein the BP SEI message includes parameters associated with a maximum number of temporal sublayers specified by bp_max_sublayers_minus1.
17 . The non-transitory computer readable medium of claim 16 , wherein the parameters in the BP SEI message include an initial coded picture buffer (CPB) removal delay and an initial CPB removal offset.
18 . The non-transitory computer readable medium of claim 15 , wherein the maximum number of sublayers specified by the VPS is included in a VPS maximum sublayers minus one (vps_max_sublayers_minus1) plus one.
19 . The non-transitory computer readable medium of claim 18 , wherein the vps_max_sublayers_minus1 is contained in the VPS.
20 . The non-transitory computer readable medium of claim 16 , wherein the HRD is initialized at a position of an associated access unit (AU) in decoding order based on the BP SEI message.