# US 12,015,795 B2 · Signaling of slice types in video pictures headers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,795 B2 - Document ID: US12015795B2 - Status: Granted - Kind: B2 - Application number: 17/849,293 - Filed: 2022-06-24 - Published: 2023-02-16 - Granted: 2024-06-18 - Earliest claimed: 2019-12-27 - Assignees: Beijing Bytedance Network Technology Co., Ltd.; Bytedance Inc. - Applicants: Beijing Bytedance Network Technology Co., Ltd.; Bytedance Inc. - Inventors: Kai Zhang; Li Zhang; Hongbin Liu; Zhipin Deng; Jizheng Xu; Ye-kui Wang - Web page: https://patentgrep.com/patent/US12015795B2 ## CPC - H04N 19/172: the region being a picture, frame or field - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Devices, systems and methods related to digital video coding, and specifically, to signaling of slice types in video picture headers are described. One example method of video processing includes performing a conversion between a video including one or more video pictures including one or more slices and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that for a video picture of the one or more video pictures having all slices coded as I slices, P slice and B slice related syntax elements are omitted from a picture header for the video picture. ## Claims ### Claim 1 A method of video processing, comprising: determining, for a conversion between a first video picture of a video comprising one or more video pictures and a bitstream of the video, a value of a first syntax element included in a picture header for the first video picture, wherein the first syntax element indicates whether all slices included in the first video picture are I slices; determining, based on the value of the first syntax element, whether to signal a second syntax element in a slice header of a slice included in the first video picture, wherein the second syntax element indicates a slice type of the slice; and performing the conversion based on the determining, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, the second syntax element is omitted from slice headers of all slices included in the first video picture, and a value of the second syntax element is inferred to indicate an I slice, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, one or more syntax elements are omitted from the picture header for the first video picture in the bitstream, wherein the one or more syntax elements comprise a third syntax element specifying usage of a first prediction mode for the first video picture, wherein, in the first prediction mode, a signaled motion vector is refined based on at least one motion vector with an offset to the signaled motion vector, and wherein the one or more syntax elements are conditionally included in the picture header when the value of the first syntax element does not indicate all slices included in the first video picture are I slices. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more syntax elements further comprise at least one of: temporal_mvp_enabled_flag, mvd_l1_zero_flag, a fourth syntax element specifying a usage of a second prediction mode for the first video picture, or a fifth syntax element specifying a usage of a third prediction mode for the first video picture, wherein, in the second prediction mode, for a video block in the first video picture, a bi-directional optical flow tool is used to obtain a motion vector offset based on at least one gradient value corresponding to a sample in a reference block of the video block, and wherein, in the third prediction mode, for a video block in the first video picture, initial prediction samples of a sub-block of the video block coded with an affine mode is generated, and an optical flow operation is applied to generate final prediction samples for the sub-block by deriving a prediction refinement based on motion vector differences dMvH or dMvV, wherein dMvH and dMvV indicate motion vector differences along a horizontal direction and a vertical direction, respectively. ### Claim 3 (depends on 1) The method of claim 1, wherein the one or more syntax elements further comprise at least one of: log 2_diff_min_qt_min_cb_inter_slice, max_mtt_hierarchy_depth_inter_slice, log 2_diff_max_bt_min_qt_inter_slice, or log 2_diff_max_tt_min_qt_inter_slice. ### Claim 4 (depends on 1) The method of claim 1, wherein an intra slice allowed flag is conditionally included in the picture header. ### Claim 5 (depends on 1) The method of claim 1, wherein the first video picture comprises one or more tiles, wherein a maximum tile width of the one or more tiles is defined as a maximum luma tile width in units of coding tree blocks, and a maximum tile height of the one or more tiles is defined as a maximum luma tile height in units of coding tree blocks. ### Claim 6 (depends on 1) The method of claim 1, wherein the conversion includes decoding the video from the bitstream. ### Claim 7 (depends on 1) The method of claim 1, wherein the conversion includes encoding the video into the bitstream. ### Claim 8 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: determine, for a conversion between a first video picture of a video comprising one or more video pictures and a bitstream of the video, a value of a first syntax element included in a picture header for the first video picture, wherein the first syntax element indicates whether all slices included in the first video picture are I slices; determine, based on the value of the first syntax element, whether to signal a second syntax element in a slice header of a slice included in the first video picture, wherein the second syntax element indicates a slice type of the slice; and perform the conversion based on the determining, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, the second syntax element is omitted from slice headers of all slices included in the first video picture, and a value of the second syntax element is inferred to indicate an I slice, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, one or more syntax elements are omitted from the picture header for the first video picture in the bitstream, wherein the one or more syntax elements comprise a third syntax element specifying usage of a first prediction mode for the first video picture, wherein, in the first prediction mode, a signaled motion vector is refined based on at least one motion vector with an offset to the signaled motion vector, and wherein the one or more syntax elements are conditionally included in the picture header when the value of the first syntax element does not indicate all slices included in the first video picture are I slices. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the one or more syntax elements further comprise at least one of: temporal_mvp_enabled_flag, mvd_l1_zero_flag, a fourth syntax element specifying a usage of a second prediction mode for the first video picture, or a fifth syntax element specifying a usage of a third prediction mode for the first video picture, wherein, in the second prediction mode, for a video block in the first video picture, a bi-directional optical flow tool is used to obtain a motion vector offset based on at least one gradient value corresponding to a sample in a reference block of the video block, and wherein, in the third prediction mode, for a video block in the first video picture, initial prediction samples of a sub-block of the video block coded with an affine mode is generated, and an optical flow operation is applied to generate final prediction samples for the sub-block by deriving a prediction refinement based on motion vector differences dMvH or dMvV, wherein dMvH and dMvV indicate motion vector differences along a horizontal direction and a vertical direction. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the one or more syntax elements further comprise at least one of: log 2_diff_min_qt_min_cb_inter_slice, max_mtt_hierarchy_depth_inter_slice, log 2_diff_max_bt_min_qt_inter_slice, or log 2_diff_max_tt_min_qt_inter_slice. ### Claim 11 A non-transitory computer-readable storage medium storing instructions that cause a processor to: determine, for a conversion between a first video picture of a video comprising one or more video pictures and a bitstream of the video, a value of a first syntax element included in a picture header for the first video picture, wherein the first syntax element indicates whether all slices included in the first video picture are I slices; determine, based on the value of the first syntax element, whether to signal a second syntax element in a slice header of a slice included in the first video picture, wherein the second syntax element indicates slice type of the slice; and perform the conversion based on the determining, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, the second syntax element is omitted from slice headers of all slices included in the first video picture, and a value of the second syntax element is inferred to indicate I slice, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, one or more syntax elements are omitted from the picture header for the first video picture in the bitstream, wherein the one or more syntax elements comprise a third syntax element specifying usage of a first prediction mode for the first video picture, wherein, in the first prediction mode, a signaled motion vector is refined based on at least one motion vector with an offset to the signaled motion vector, and wherein the one or more syntax elements are conditionally included in the picture header when the value of the first syntax element does not indicate all slices included in the first video picture are I slices. ### Claim 12 A non-transitory computer-readable storage medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determine, for a first video picture of a video comprising one or more video pictures, a value of a first syntax element included in a picture header for the first video picture, wherein the first syntax element indicates whether all slices included in the first video picture are I slices; determine, based on the value of the first syntax element, whether to signal a second syntax element in a slice header of a slice included in the first video picture, wherein the second syntax element indicates a slice type of the slice; and generating the bitstream based on the determining, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, the second syntax element is omitted from slice headers of all slices included in the first video picture, and a value of the second syntax element is inferred to indicate an I slice, wherein, in response to the value of the first syntax element indicating that all slices included in the first video picture are I slices, one or more syntax elements are omitted from the picture header for the first video picture in the bitstream, wherein the one or more syntax elements comprise a third syntax element specifying usage of a first prediction mode for the first video picture, wherein, in the first prediction mode, a signaled motion vector is refined based on at least one motion vector with an offset to the signaled motion vector, and wherein the one or more syntax elements are conditionally included in the picture header when the value of the first syntax element does not indicate all slices included in the first video picture are I slices. ### Claim 13 (depends on 1) The method of claim 1, wherein the first video picture comprises one or more slices, and wherein a maximum slice height of the one or more slices is defined in units of coding tree blocks. ### Claim 14 (depends on 8) The apparatus of claim 8, wherein an intra slice allowed flag is conditionally included in the picture header. ### Claim 15 (depends on 8) The apparatus of claim 8, wherein the first video picture comprises one or more tiles, wherein a maximum tile width of the one or more tiles is defined as a maximum luma tile width in units of coding tree blocks, and wherein a maximum tile height of the one or more tiles is defined as a maximum luma tile height in units of coding tree blocks. ### Claim 16 (depends on 8) The apparatus of claim 8, wherein the first video picture comprises one or more slices, and wherein a maximum slice height of the one or more slices is defined in units of coding tree blocks. ### Claim 17 (depends on 11) The non-transitory computer-readable storage medium of claim 11, wherein the one or more syntax elements further comprise at least one of: a temporal_mvp_enabled_flag, an mvd_l1_zero_flag, a fourth syntax element specifying a usage of a second prediction mode for the first video picture, or a fifth syntax element specifying a usage of a third prediction mode for the first video picture, wherein, in the second prediction mode, for a video block in the first video picture, a bi-directional optical flow tool is used to obtain a motion vector offset based on at least one gradient value corresponding to a sample in a reference block of the video block, and wherein, in the third prediction mode, for a video block in the first video picture, initial prediction samples of a sub-block of the video block coded with an affine mode is generated, and an optical flow operation is applied to generate final prediction samples for the sub-block by deriving a prediction refinement based on motion vector differences dMvH or dMvV, and wherein dMvH and dMvV indicate motion vector differences along a horizontal direction and a vertical direction, respectively. ### Claim 18 (depends on 11) The non-transitory computer-readable storage medium of claim 11, wherein the one or more syntax elements further comprise at least one of: log 2_diff_min_qt_min_cb_inter_slice, max_mtt_hierarchy_depth_inter_slice, log 2_diff_max_bt_min_qt_inter_slice, or log 2_diff_max_tt_min_qt_inter_slice. ### Claim 19 (depends on 12) The non-transitory computer-readable storage medium of claim 12, wherein the one or more syntax elements further comprise at least one of: a temporal_mvp_enabled_flag, an mvd_l1_zero_flag, a fourth syntax element specifying a usage of a second prediction mode for the first video picture, or a fifth syntax element specifying a usage of a third prediction mode for the first video picture, wherein, in the second prediction mode, for a video block in the first video picture, a bi-directional optical flow tool is used to obtain a motion vector offset based on at least one gradient value corresponding to a sample in a reference block of the video block, and wherein, in the third prediction mode, for a video block in the first video picture, initial prediction samples of a sub-block of the video block coded with an affine mode is generated, and an optical flow operation is applied to generate final prediction samples for the sub-block by deriving a prediction refinement based on motion vector differences dMvH or dMvV, and wherein dMvH and dMvV indicate motion vector differences along a horizontal direction and a vertical direction, respectively. ### Claim 20 (depends on 12) The non-transitory computer-readable storage medium of claim 12, wherein the one or more syntax elements further comprise at least one of: log 2_diff_min_qt_min_cb_inter_slice, max_mtt_hierarchy_depth_inter_slice, log 2_diff_max_bt_min_qt_inter_slice, or log 2_diff_max_tt_min_qt_inter_slice.