Constituent rectangles SEI and display overlays SEI messages

Abstract

A mechanism for processing video data is disclosed. The mechanism includes determining one or more syntax elements signalled to specify a related value of a bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID. A conversion is performed between a visual media data and a bitstream based on the one or more syntax elements.

Description

Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)Constituent Rectangles SEI And Display Overlays SEI MessagesCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority to and benefits of U.S. Provisional Patent Application No. 63 / 700,385 filed on September 1 , 2024, which is herein incorporated by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to generation, storage, and consumption of digital audio video media information in a file format.BACKGROUND

[0003] Digital video accounts for the largest bandwidth used on the Internet and other digital communication networks. As the number of connected user devices capable of receiving and displaying video increases, the bandwidth demand for digital video usage is likely to continue to grow.SUMMARY

[0004] A first aspect relates to a method for processing video data comprising: determining one or more syntax elements signalled to specify a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; and performing a conversion between a visual media data and a bitstream based on the one or more syntax elements.

[0005] A second aspect relates to 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 any of the preceding aspects.

[0006] A third aspect relates to 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 perform the method of any of the preceding aspects.

[0007] A fourth aspect relates to a non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining one or more syntax elements signalled to specily a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; and generating a bitstream based on the determining.

[0008] A fifth aspect relates to a method for storing bitstream of a video comprising: determining one or more syntax elements signalled to specify a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; generating a bitstream based on the determining; and storing the bitstream in a non-transitory computer-readable recording medium.

[0009] A sixth aspect relates to a method, apparatus, or system described in the present disclosure.

[0010] For the purpose of clarity, any one of the foregoing embodiments may be combined with any one or more of the other foregoing embodiments to create a new embodiment within the scope of the present disclosure.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0011] These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.

[0013] FIG. 1 is a block diagram showing an example video processing system.

[0014] FIG. 2 is a block diagram of an example video processing apparatus.

[0015] FIG. 3 is a flowchart for an example method of video processing.

[0016] FIG. 4 is a block diagram that illustrates an example video coding system.

[0017] FIG. 5 is a block diagram that illustrates an example encoder.

[0018] FIG. 6 is a block diagram that illustrates an example decoder.

[0019] FIG. 7 is a schematic diagram of an example encoder.DETAILED DESCRIPTION

[0020] It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and / or methods may be implemented using any number of techniques, whether currently known or yet to be developed. The disclosure should in no wax’ be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents.

[0021] Section headings are used in the present disclosure for ease of understanding and do not limit the applicability of techniques and embodiments disclosed in each section only to that section. Furthermore, H.266 terminology is used in some description only for ease of understanding and not for limiting scope of the disclosed embodiments. As such, the embodiments described herein are applicable to other video codec protocols and designs also. In the present disclosure, editing changes are shown to text by triple brackets indicating cancelled text (i.e., [[[a]]] indicates that ‘a’ is deleted), and double braces indicating added text (i.e., { {a} } indicates that ‘a’ is added), with respect to the Versatile Video Coding (WC) specification.1. Initial discussion

[0022] This disclosure is related to image / video coding technologies. Specifically, this disclosure is related to the constituent rectangles supplemental enhancement information (SEI) message and the display overlays SEI message. The ideas may be applied individually or in various combinations, for video bitstreams coded by any codec, e.g.. the versatile video coding (WC) standard and / or the versatile SEI messages for coded video bitstreams (VSEI) standard.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)2. Abbreviations

[0023] The following abbreviations may be used herein: adaptation parameter set (APS), access unit (AU), coded layer video sequence (CLVS), coded layer video sequence start (CLVSS), cyclic redundancy check (CRC), coded video sequence (CVS), finite impulse response (FIR), intra random access point (IRAP), network abstraction layer (NAL), neural-network post-processing fdter (NNPF), neural-network post-filter activation (NNPFA), neural-network post-filter characteristics (NNPFC), picture parameter set (PPS), picture unit (PU), random access skipped leading (RASL) picture, supplemental enhancement information (SEI), step-wise temporal sublayer access (STSA), uniform resource identifier (URI), video coding layer (VCL), versatile supplemental enhancement information as described in Rec. ITU-T H.274 | ISO / IEC 23002-7 (VSEI), video usability information (VUI), versatile video coding as described in Rec. ITU-T H.266 | ISO / IEC 23090-3 (WC)3. Further discussion3.1 Video coding standards

[0024] Video coding standards have evolved primarily through the development of International Telecommunication Union (ITU) telecommunication standardization sector (ITU-T) and International Organization for Standardization (ISO) / International Electrotechnical Commission (IEC) standards. The ITU-T produced H.261 and H.263, ISO / IEC produced motion picture experts group (MPEG)-1 and MPEG-4 Visual, and the two organizations jointly produced the H.262 / MPEG-2 Video and H.264 / MPEG-4 Advanced Video Coding (AVC) and H.265 / high efficiency video coding (HEVC) [1] standards. Since H.262, the video coding standards are based on the hybrid video coding structure wherein temporal prediction plus transform coding are utilized. To explore video coding technologies beyond high efficiency video coding (HEVC), the Joint Video Exploration Team (JVET) was founded by video coding experts group (VCEG) and motion picture experts group (MPEG). Further, methods have been adopted by JVET and put into the reference software named Joint Exploration Model (JEM) [2], The JVET was later renamed to be the Joint Video Experts Team (JVET) when the Versatile Video Coding (WC) project officially started. WC [3] is a coding standard targeting at 50% bitrate reduction as compared to HEVC.

[0025] The Versatile Video Coding (WC) standard (ITU-T H.266 | ISO / IEC 23090-3) [3] and the associated Versatile Supplemental Enhancement Information for coded video bitstreams (VSEI) standard (ITU-T H.274 | ISO / IEC 23002-7) [4] are designed for use in a maximally broad range of applications, including both the simple uses such as television broadcast, video conferencing, or playback from storage media, and also more advanced use cases such as adaptive bit rate streaming, video region extraction, composition and merging of content from multiple coded video bitstreams, multiview video, scalable layered coding, and viewport-adaptive 360° immersive media.

[0026] The Essential Video Coding (EVC) standard (ISO / IEC 23094-1) is another video coding standard under development by MPEG.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)3.2 SEI messages in general and in WC and VSEI

[0027] SEI messages assist in processes related to decoding, display or other purposes. However, SEI messages are not required for constructing the luma or chroma samples by the decoding process. Conforming decoders are not required to process this information for output order conformance. Some SEI messages are required for checking bitstream conformance and for output timing decoder conformance. Other SEI messages are not required for check bitstream conformance.

[0028] Annex D of WC specifies syntax and semantics for SEI message payloads for some SEI messages, and specifies the use of the SEI messages and VUI parameters for which the syntax and semantics are specified in ITU-T H.274 | ISO / IEC 23002-7.3.3 Constituent rectangles SEI message

[0029] In the document of technologies under consideration for extensions of VSEI [5], a constituent rectangles SEI message is described as below.8.40 Constituent rectangles SEI message8.40.1 Constituent rectangles SEI message syntaxAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)8.40.2 Constituent rectangles SEI message semantics

[0030] The constituent rectangles SEI message enables composition of multiple rectangles within a coded picture and provides information about the rectangles, including ID, type, text description, location, and size.

[0031] Use of this SEI message requires the definition of the following variables:A picture width and picture height in units of luma samples, denoted herein by PicWidthlnLumaSamples and PicHeightlnLumaSamples. respectively.A maximum picture width and maximum picture height in units of luma samples, denoted herein by MaxPicWidth and MaxPicHeight, respectively.- A chroma format indicator, denoted herein by ChromaFormatldc, as described in clause 7.3.- A bit depth for the samples of the luma component, denoted herein by BitDepthy, and when ChromaFormatldc is not equal to 0, a bit depth for the samples of the two associated chroma components, denoted herein by BitDepthc.- A subpicturc count, denoted by NumSubpics.- Arrays of the top left X and Y positions of the subpictures, denoted herein by SubPicTopLeftXf i ] and SubPicTopLeftYf i ]. respectively.Arrays of the width and height of the subpictures, denoted herein by SubPicTopLeftX[ i ] and SubPicTopLeftY[ i ]. respectively.

[0032] If this SEI message is present in any picture unit that is not the first picture unit of a CLVS in decoding order, a constituent rectangles SEI message with the same payload content shall be present in the first picture unit of the CLVS in decoding order.

[0033] cr num rects minusl plus 1 specifies the number of constituent rectangles for which information is signalled in the SEI message.

[0034] cr rect id enabled flag equal to 1 specifies that the cr_rect_id_present_flag syntax element is present in the SEI message. cr_rect_id_present_flag equal to 0 specifies that the cr_rect_id_present_flag syntax element is not present in the SEI message.

[0035] cr associated rect id enabled flag equal to 1 specifies that the cr_associated_rect_id_present_flag[ i ] syntax elements are present, cr associated rect id enabled flag equal to 0 specifies that the cr_associated_rect_id_present_flag[ i ] syntax elements are not present.

[0036] cr reel group id present flag equal to 1 specifies that cr rect_group id[ i ] syntax elements are present. cr_recUgroup_present_flag equal to 0 specifies that_cr_rect_group_id[ i J syntax elements are not present.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0037] cr rect id len specifies the length of the cr_rect_id[ i ], cr associated rect id [ i ], and cr_rcct_group_id| i ] syntax elements, syntax elements.

[0038] cr rect type enabled flag equal to 1 specifies that the cr_rect_type_present_flag[ i ] syntax element is present in the SEI message, cr rect type enabled flag equal to 0 specifies that the cr_rect_type_ present_flag[ i ] syntax element is not present in the SEI message.

[0039] cr rect type descriptions enabled flag equal to 1 specifies that the cr_rect_type_description_present_flag[ i ] syntax element is present in the SEI message, cr rect type descriptions enabled flag equal to 0 specifies that the cr_rect_type_description_present_flag[ i ] syntax element is not present in the SEI message.

[0040] cr_subpics_partitioning_flag equal to 1 indicates that the subpic partitioning parameters in the SPS are used to determine the of constituent rectangle sizes and positions, cr subpics partitioning flag equal to 0 indicates that determination of the constituent rectangle sizes and positions is not based on subpic partitioning parameters in the SPS.

[0041] When cr_subpics_partitioning_flag is equal to 1, it is a requirement of bitstream conformance that NumSubpics be greater than or equal to cr num rects minusl + 1.

[0042] cr rect same size flag equal to 1 indicates that all constituent rectangles have the same size and are arranged in a grid pattern, cr rect same size flag equal to 0 indicates that the sizes of the constituent rectangles may differ.

[0043] cr num cols minusl plus 1 and cr num rows minus 1 plus 1 specify the number of columns and rows, respectively, of the constituent rectangle grid when cr rect same size flag equal to 1.

[0044] The variable crNumCols is set equal to cr num cols minusl + 1.

[0045] The variable crNumRows is set equal to cr num rows minusl + 1.

[0046] cr_log2_unit_size specifies a unit size used in variable calculations for the constituent rectangle parameters.

[0047] The variable crUnitSize is set equal to 1 « cr_log2_unit_size.

[0048] cr rect size len minusl plus 1 specifies the length of syntax elements cr_rcct_top_lcft_in_units_x[ i ], cr_rcct_top_lcft_in_units_y[ i ], cr rcct width in units minus 1 [ i ], and cr rect heiglit in units minus 1 [ i ].

[0049] cr_rect_type_present_flag[ i ] equal to 1 specifies that the cr_rect_type_idc[ i ] syntax element is present in the SEI message. cr_rect_type_present_flag[ i ] equal to 0 specifies that the cr_rect_type_idc[ i ] syntax element is not present in the SEI message.

[0050] cr_rect_type_idc[ i ] indicates the constituent picture type of the i-th rectangle from Table X. When not present and i equal to 0, the value of cr_rect_type_idc[ i ] is inferred to be equal to 0. When not present and i greater than 0, cr_rect_type_idc[ i ] is inferred to be equal to cr_rect_type_idc[ i - 1 ].Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)Table X - Mapping of cr_rect_type_idc[ i ] to the type of constituent rectangle

[0051] cr_rect_id_present_flag equal to 1 specifies that the cr_rect_id[ i ] syntax element is present in the SEI message. cr_rect_id_present_flag equal to 0 specifies that the cr_rect_id[ i ] syntax element is not present in the SEI message.

[0052] cr_rect_id[ i ] indicates the ID of the i-th rectangle. The length of the syntax element is cr rect id len bits. When not present and i equal to 0, the value of cr_rcct_id[ i ] is inferred to be equal to 0. When not present and i greater than 0. the value of cr_rect_id[ i ] is inferred to be equal to cr_rect_id[ i - 1 ] + 1.

[0053] It is a requirement of bitstream conformance that when j not equal to k, cr_rect_id[j ] shall not be equal to cr_rect_id[ k ].

[0054] cr_associated_rect_id_present_flag equal to 1 specifies that the cr_associated_rect_id[ i ] syntax element is present in the SEI message, cr rect id present flag equal to 0 specifies that the cr_associated_rect_id[ i ] syntax element is not present in the SEI message.

[0055] cr_associated_rect_id[ i ] indicates the ID of an associated primary rectangle of the i-th rectangle. The length of the syntax element is cr rect id len bits.

[0056] It is a requirement of bitstream conformance that cr_associated_rect_id[ i ] equal cr_rect_id[ j ] for some value of j in 0 .. cr num rects minusl.

[0057] When not present, the value of cr_associated_rect_id[ i ] is undefined.

[0058] cr_rcct_group_id| i ] indicates the group ID of the i-th rectangle. The length of the syntax element is cr rect id len bits. When not present, the value of cr_rcct_group_id| i ] is inferred to be equal to 0.

[0059] cr_rect_type_description_present_flag[ i ] equal to 1 specifies that the cr_rect_type_description[ i ] syntax element is present in the SEI message, cr rect _type description present flag| i ] equal to 0 specifies thatAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) the cr_rect_type_description[ i ] syntax element is not present in the SEI message. When not present, the value of cr_rect_type_description_present_flag[ i ] is inferred to be equal to 0.

[0060] cr_rect_top_left_in_units_x[ i ] and cr_rect_top_left_in_units_y[ i ], when present, indicate the horizontal and vertical positions, respectively, of the top left position of the i-th constituent picture rectangle in units.

[0061] The variables SubWidthC and SubHeightC are derived from ChromaFormatldc as specified by Table 2.

[0062] cr_rect_width_in_units_minusl[ i ] plus 1 and cr rect heiglit in units minus 1 [ i ] plus 1, when present, indicate the width and height, respectively, of the i-th constituent rectangle in units. The length of the syntax elements are cr rect size len minusl + 1.

[0063] The variables crRectTopLeftXf i ] and crRecflopLeftYf i ], representing the x and y location, respectively, and variables crRectWidth[ i ] and crRectHeight[ i ], representing the width and height, respectively, of the i-th constituent rectangle are derived as follows.

[0064] If cr_subpics_partitioning_flag is equal to 0 and cr rect same size flag is equal to 0, the following applies:- The variable crRectTopLeftXf i ] is set equal to cr_rect_top_left_in_units_x[ i ] * crUnitSize- The variable crRectTopLeftYf i ] is set equal to cr_rect_top_left_in_units_y[ i ] * crUnitSize- The variable crRectWidthf i ] is set equal to ( cr rcct width in units minus 1 + 1 ) * crUnitSize- The variable crRectHeight[ i ] is set equal to ( cr rect height in units minus 1 + 1 ) * crUnitSize

[0065] Otherwise, if cr_subpics_partitioning_flag is equal to 1, the following applies:The variable crRectTopLeftX[ i ] is set equal to SubPicTopLeftX[ i ]The variable crRectTopLeftY[ i ] is set equal to SubPicTopLeftY[ i ]The variable crRectWidthf i ] is set equal to SubPicWidthf i ]The variable crRectHeight[ i J is set to equal to SubPicHeight[ i ]

[0066] Otherwise (cr rect same size flag is equal to 1), the following applies:- The variable crRectTopLeftX[ i ] is set equal to (i % crNumCols ) * MaxPicWidth / crNumCols- The variable crRectTopLeftY[ i ] is set equal to (i / crNumCols ) * MaxPicHeight / crNumRows- The variable crRectWidth [ i ] is set equal to MaxPicWidth / crNumCols- The variable crRectHeight [ i ] is set to equal to MaxPicHeight / crNumRows

[0067] When PicWidthlnLumaSamples is not equal to MaxPicWidth, the following applies:- crRectTopLeftXf i ] is set equal to (crRectTopLeftX[ i ] * PicWidthlnLumaSamples + MaxPicWidth / 2 ) / MaxPicWidth crRectWidth[ i ] is set equal to (crRectWidthf i ] * PicWidthlnLumaSamples + MaxPicWidth / 2 ) / MaxPicWidth

[0068] When PicHeightlnLumaSamples is not equal to MaxPicHeight, the following applies:Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) crRectTopLeftY[ i ] is set equal to (crRectTopLeftY[ i ] * PicWidthlnLumaSamples + MaxPicHeight / 2 ) / MaxPicHeight- crRectHeight[ i ] is set equal to (crRectHeight[ i ] * PicWidthlnLumaSamples + MaxPicHeight / 2 ) / MaxPicHeight

[0069] It is a requirement of bitstream conformance that for each sample position (x, y) in the coded picture there shall be at most one rectangle, j, for which both of the following conditions apply:- x is in (crRcctTopLcftX[j ] .. crRcctTopLcftX[ j ] + crRcctWidthf j ] - 1)- y is in (crRectTopLeftY[ j ] .. crRectTopLeftY[ j ] + crRectHeight[ i ] - 1)

[0070] It is a requirement of bitstream conformance that crRectTopLeftX[ i ] % SubWidthC shall be equal to 0, crRectTopLeftX [ i ] % SubHeightC shall be equal to 0, crRectWidthf i ] % SubWidthC shall be equal to 0, and crRectHeight[ i ] % SubHeightC shall be equal to 0.

[0071] cr bit equal to zero shall be equal to 0.

[0072] cr_rect_type_description[ i ] specifies a text description of the constituent rectangle. The length of the syntax element shall be less than or equal to 4097 bytes, not including the null termination byte.3.4 Constituent rectangles SEI message

[0073] In the document of technologies under consideration for future extensions of VSEI [5], a display overlays information SEI message is described as below.8.43 Display overlays SEI message8.43.1 Display overlays SEI message syntaxAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)8.43.2 Display overlays SEI message semantics

[0074] The display overlays information (DOI) SEI message provides metadata to enable formation of a target display picture formed by overlaying multiple ordered display overlays in a specified order. A display overlay contains texture and optionally an alpha channel, each contained within a cropped decoded picture, a subpicture, and / or a constituent rectangle.

[0075] Use of this SEI message requires the definition of the following variables, where i is the layer identifier of a layer that may be present in the current CVS:- An array of picture width and picture height in units of luma samples, denoted herein by PicWidthInLumaSamples[ i ] and PicHeightInLumaSamples[ i ], respectively.A chroma format indicator, denoted herein by ChromaFormatIdc[ i ], as described in subclause 7.3.An array of subpicture counts, denoted by NumSubpics[ i ].Arrays of the width and height of the subpictures, denoted herein by SubPicWidthf i ][ j ] and SubPicHeight[ i ][ j ] respectively, where j is the subpicture index in 0 .. NumSubpics[ i ] - 1.

[0076] doi id specifies an identifier of the DOI SEI message.

[0077] doi cancel flag equal to 1 indicates that the SEI message cancels the persistence of any previous DOI SEI message with the same doi id in output order, doi cancel flag equal to 0 indicates that display overlays information follows.

[0078] doi_pcrsistcncc_flag specifics the persistence of the DOI SEI message for the CVS.

[0079] doi_persistence_flag equal to 0 specifies that the DOI SEI message applies to the current AU only.

[0080] doi_persistence_idc equal to 1 specifies that the DOI SEI message applies to the current AU and persists for all subsequent AUs in output order until one or more of the following conditions are true:A new CVS begins.The bitstream ends.A picture in the current AU with a DOI SEI message with the same value of doi id is output that follow's the current picture in output order.

[0081] doi_num_display_ovcrlays_minus2 plus 2 specifies the number of display overlays for which information is signalled in the SEI message. The value of doi_num_display_overlays_minus2 shall be in the range of 0 to 30, inclusive.

[0082] doi_target_pic_size_present_flag equal to 1 specifies that the doi_target_pic_width_minusl and doi_target_pic_width_minusl syntax elements are present. doi_target_pic_size_present_flag equal to 0 specifies that the doi_target_pic_width_minusl and doi_target_pic_width_minus 1 syntax elements are present.

[0083] doi_target_pic_width_minusl + 1, when present, indicates the width of the target picture.

[0084] doi_target_pic_height_minusl+ 1, when present, indicates the height of the target picture.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0085] doi_nuh_layer_id_present flag equal to 1 specifies that the doi_nuh_layer_id[ i ] syntax element is present in the SEI message. doi_nuh_layer_id_present_flag equal to 0 specifies that the doi_nuh_layer_id[ i ] syntax element is not present in the SEI message.

[0086] doi_pic_partition_flag equal to 1 specifies that display overlay components are coded as constituent rectangles or subpictures. doi_pic_partition_flag equal to 0 specifies that display overlay components are coded as pictures.

[0087] It is a requirement of bitstream conformance that at least one of doi_nuh_layer_id_present_flag or doi_pic_partition_flag shall be equal to 1.

[0088] doi_partition_type_flag equal to 1 specifies that a display overlay component is coded as a constituent rectangle, doi _partition_typc_flag equal to 0 specifies that a display overlay component is coded as a subpicture.

[0089] When doi_partition_type_flag equal to 1, it is a requirement of bitstream conformance that there is a constituent rectangles SEI message preceding the DOI SEI message in decoding order in the current PU.

[0090] doi_partition_id_len_minusl + 1 specifies the length of the doi_partition_id[ i ] syntax elements.

[0091] doi_offset_params_present_flag[ i ] equal to 1 specifies that offset parameters are present for the i-th display overlay. doi_offset_params_present_flag[ i ] equal to 0 specifies that offset parameters are not present for the i-th display overlay.

[0092] doi_offset_param_length_minusl plus 1 specifies the length of the doi_top_left_x[ i ] and doi_top_left_y[ i ], syntax elements in bits.

[0093] doi resampling enabled flag equal to 1 specifies that display overlay components may be resampled in the target display picture, doi resampling enabled flag equal to 0 specifies that display overlay components are not resampled in the target display picture.

[0094] doi_size_param_length_minusl plus 1 specifies the length of the doi_width_minusl [ i ] and doi height minusl [ i ] syntax elements in bits.

[0095] doi_nuh_layer_id[ i ], when present, specifies the layer identifier of the texture component of the i-th display overlay. When not present, the value of doi_nuh_layer_id[ i ] is inferred to be equal to the layer identifier of the PU containing the DOI SEI message.

[0096] If this SEI message is present in any layer in the current AU, it is a requirement of bitstream conformance that a DOI SEI message with the same value of doi id and the same payload is present in the lay er with layer identifier doi_nuh_layer_id

[0000] .

[0097] doi_partition_id[ i ], when present and doi_partition_type_flag equal to 1. specifies that the texture component of the i-th display overlay is represented by the j-th constituent rectangle when cr_rect_id[ j ] equal doi partition id[ i | doi partition id[ i ], when present and doi_partition type flag equal to 0, specifies the subpicture index of the texture component of the i-th display overlay. When not present, the value of doi_partition_id[ i ] is inferred to be equal to 0.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0098] When doi_partition_type flag equal to 1, doi_partition_id[ i ] shall be in the range of 0 .. cr num rects minusl [ doi_nuh_layer_id[ i ] ] - 1. When doi_partition_type_flag equal to 0, doi_partition_id[ i ] shall be in the range of 0 .. NumSubpics[ doi_nuli_layer_id| i ] ] - 1.

[0099] doi_alpha_present_flag[ i ] equal to 1 specifies that an alpha component is provided for the i-th display overlay. doi_alpha_present_flag[ i ] equal to 0 specifies that an alpha component is not provided for the i-th display overlay.

[0100] doi_alpha_nuh_layer_id[ i ], when present, specifies the layer identifier value of the alpha component of the i-th display overlay. When not present, the value of doi_alpha_nuh_layer_id[ i ] is inferred to be equal to the layer identifier of the PU containing the DOI SEI message.

[0101] doi_alpha_partition_id[ i ], when present and doi_partition_type_flag equal to 1, specifies the er rect id[ j ] of the alpha component of the i-th display overlay, doi partition id[ i ], when present and doi_partition_type_flag equal to 0, specifies the subpicture index of the alpha component of the i-th display overlay. When not present, the value of doi_alpha_partition_id[ i ] is inferred to be equal to 0.

[0102] When doi_partition_type_flag equal to 1, doi_alpha_partition_id[ i ] shall be in the range of 0 .. cr_num_rects_minusl [ doi_nuh_layer_id[ i ] ] - 1. When doi_partition_type_flag equal to 0, doi_alpha_partition_id[ i ] shall be in the range of 0 .. NumSubpics[ doi_nuh_layer_id| i ] ] - 1.

[0103] doi_top_left_x[ i ] and doi_top_left_y[ i ] specify the horizontal and vertical positions, respectively, of the top left comer of the i-th display overlay in the target display picture, in luma samples. When not present, the values of doi_top_left_x[ i ] and doi_top_left_y[ i ] are inferred to be equal to 0. The length of the syntax elements is doi_offset_param_length_minusl + 1 bits.

[0104] doi_width_minusl [ i ] plus 1 and doi_height_minusl[ i ] plus 1. when present, specify the width and height, respectively, in luma samples arrays of the i-th display overlay in the target display picture. The length of the syntax elements is doi_size_param_length_minusl + 1 bits.

[0105] The variables CodedOverlayTexture[ i ] and CodedOverlayAlpha[ i ] are picture sample arrays with luma resolution CodedOverlayWidthf i ] x CodedOverlayHeight[ i ], derived as follows:- If doi_pic_partition_flag is equal to 0, the following applies:- CodedOverlayWidth[ i ] is set equal to PicWidthInLumaSamples[ doi nuh lay er_id[ i ] ] ].- CodedOverlay Hcight| i ] is set equal to PicWidthInLumaSamples[ doi_nuh_layer_id[ i ] ].- If there is a picture in the AU for the lay er with layer identifier doi_nuh_layer_id[ i ], CodedOverlayTexture[ i ] is set equal to the cropped decoded picture from the layer with layer identifier doi_nuh_layer_id[ i ] in the AU. Otherwise (there is no picture in the AU for the layer with layer identifier doi_nuh_layer_id[ i ]), CodedOverlayTexture[ i ] is set equal to the previous cropped decoded picture in output order in the layer with layer identifier doi_nuh_layer_id[ i ].Otherwise, the following applies:If doi_alpha_present_flag[ i ] equal to 1, the following applies:Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)- If there is a picture in the AU for the layer with layer identifier doi_alpha_nuh_layer_id[ i ], CodedOverlayAlpha[ i ] is set equal to the cropped decoded picture from the layer with layer identifier doi_alpha_nuh_layer_id[ i ] in the AU.- Otherwise (there is no picture in the AU for the layer with layer identifier doi_nuh_layer_id[ i ]),CodedO verl ay Alpha [ i ] is set equal to the previous cropped decoded picture in output order in the layer with layer identifier doi_alpha_nuh_layer_id[ i ].- Otherwise, if doi partition typc flag is equal to 0, the following applies:- CodcdOvcrlayTcxturc[ i ] is set equal to the subpicturc w ith subpicturc index doi_partition_id[ i ] from the layer with layer identifier doi_nuh_layer_id[ i ].- CodedOverlayWidth[ i ] is set equal to SubPicWidtli[ doi_nuh_layer_id[ i ] ][ doi_partition_id[ i ] ].CodedOverlayHeight[ i ] is set equal to SubPicHeight[ doi_nuh_layer_id[ i ] ][ doi_partition_id[ i ] ].If doi_alpha_present_flag[ i ] equal to 0, the following applies:CodedOverlayAlphaWidth[ i ] is set equal toSubPicWidth[ doi alpha nuh layer id[ i ] ][ doi_partition id[ i ] ].CodedOverlayAlphaHeight[ i ] is set equal toSubPicHeight[ doi_alpha_nuh_laycr_id| i ] ][ doi_partition_id[ i ] ].- CodedOverlayAlpha[ i ] is set equal to the subpicture with subpicture index doi_alpha_partition_id[ i ] from the layer with layer identifier doi_alpha_nuh_layer_id[ i ].- Otherwise (doi partition type llag is equal to 1), the following applies:- CodedOverlayWidth[ i ] is set equal to CrRectWidth[ doi_nuh_layer_id[ i ] ][ doi_partition_id[ i ] ].- CodedOverlayHeight[ i ] is set equal to CrRectHeight[ doi_nuh_layer_id[ i ] ][ doi_partition_id[ i ] ].- CodedOverlayTexture[ i ] is set equal to the constituent rectangle with cr_rect_id[ j ] equal to doi_partition_id[ i ] from the layer with layer identifier doi_nuh_layer_id[ i ].- If doi_alpha_present_flag[ i ] equal to 0CodedOverlayAlphaWidth[ i ] is set equal toCrWRectidth[ doi_alpha_nuh_layer_id[ i ] ][ doi_partition_id[ i ] ].CodedOverlayAlphaHeight[ i ] is set equal toCrRectHeightf doi alpha nuh layer id| i ] ] f doi partition id| i l l.CodedOverlayAlpha is set equal to the constituent rectangle with cr_rect_id[ j ] equal to doi_alpha_partition_id[ i ] from the layer with layer identifier doi_alpha_nuh_laycr_id| i ].

[0106] The variables DisplayOverlayTexture[ i ] and Di splay Overlap Alpha[ i ] are sample arrays with luma resolution Di splay O vcrlay Width | i ] x DisplayOverlayHeight[ i ], derived as follows:- If doi resampling enabled flag is equal to 1, the following applies:- DisplayOverlayWidth[ i ] is set equal to doi width minus 1 [ i ] + 1.- DisplayOvcrlayHcight[ i ] is set equal to doi height minus 1 [ i ] + 1.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)- OverlayTexture[ i ] is derived by resampling CodedOverlayTexture[ i ] from a luma resolution of( CodedOverlayWidth[ i ] x CodedOverlayHeight[ i ] ) to a luma resolution of ( DisplayOverlayWidth[ i ] x DisplayOverlayHeight[ i ] ).- Overlay Alpha[ i ] is derived by resampling CodedOverlay Alpha from a luma resolution of( CodedOverlayAlphaWidth[ i ] x CodedO verlay AlphaHeight [ i ] ) to a luma resolution of ( DisplayOverlayWidth[ i ] x DisplayOverlayHeight[ i ] )- Otherwise (doi resampling enabled flag is equal to 0), the following applies:- DisplayO verlay Width | i ] is set equal to CodedO verlay Width | i ].- DisplayOverlayHeight[ i ] is set equal to CodedO verlayHeight[ i ].- Overlay Texture[ i ] is set equal to CodedO verlayTexture[ i ].- OverlayAlpha[ i ] is set equal to CodedOverlayAlpha[ i ].

[0107] The variables TargetPicWidth and TargetPicHeight, for the target display picture width and height, respectively, are derived as follows:- If doi_target_pic_size_present_flag)TargetPicWidth is set equal to doi_target_pic_width_minus 1 + 1- TargetPicHeight is set equal to doi_target_pic_height_minusl + 1- Otherwise- TargetPicWidth is set equal to Display Overlay Width

[0000] .- TargetPicHeight is set equal to DisplayOverlayHeight

[0000] .

[0108] Let O verlay WithAlpha( tgtPic[ x ][ y ], ovlTcxf w ][ h ], ovlAlpf w ][ h ] ) be specified as a function that returns the sample values derived by applying the alpha channel using tgtPic[ x ] [ y ] as the background sample, ovlTexf w ][ h ] as the foreground sample, and ovlAlpf w ][ h ] as the alpha channel sample, using the process specified in subclause 8.23 if an alpha channel information SEI message is present in the CVS, or using a process determined via external means.

[0109] A target display picture should be formed as follows, with picture array, TargetPicture[ cldx ] [ x ] [ y ] , with cldx = 0..(ChromaFormatIdc = = 0 ) ? 0 : 2, x = O..( cldx = = 0 ) ? TargetPicWidth : TargetPicWidth / SubWidthC - 1, y = O..( cldx = = 0 ) ? TargetPicHeight : TargetPicHeight / SubHeightC - 1. for( i = 0; i < doi_num_display_overlays_minus2 + 2; i++ ) { for( h = 0, y = doi_top_left_y[ i ]; y < DisplayOverlayHeight[ i ]; h++, y++ ) for( w = 0, x = doi_top_left_x[ i ]; x < Display O verlay Width | i ]; w++, x++ ) if( !doi_alpha_present_flag[ i ] )TargetPicture

[0000] [ x ][ y ] = OverlayTexture[ i ]

[0000] [ w ][ h ] elseTargetPicture [ c ][ x ][ y ] = OverlayWithAlpha( TargetPicture

[0000] [ x ][ y ],Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)OverlayTexture

[0000] [ i ][ w ][ h ].OverlayAlpha[ i ] [ w ] [ h ] ) for( ( cldx = 1; cldx < ChromaFormatldc = = 0 ) ? 1 : 3; cldx++ ++ ) { for( h = 0, y = doi_top_left_y[ i ] / SubHeightC; y < DisplayOverlayHeight[ i ] / SubHeightC; h++, y'++ ) for( w = 0, x = doi_top_left_x[ i ] / SubWidthC; x < DisplayOverlayWidth[ i ] / SubWidthC; w++, x++ ) if( !doi_alplia_present_flag[ i ] )TargetPicture[ cldx ][ x ][ y ] = OverlayTexture[ i ][ cldx ][ w ][ h ] elseTargetPicture[ cldx ][ x ][ y ] =OverlayWithAlpha( TargetPicture[ cldx ][ x ][ y ],OverlayTexture[ cldx ][ i ][ w ][ h ],OverlayAlpha[ i ][ w ] [ h ] )4. Technical problems addressed by disclosed embodiments

[0110] An example design of the constituent rectangles (CR) SEI and the display overlays information (DOI) messages have the following limitations or problems:[OHl] First, the bit length of the syntax element for signalling of the constituent rectangle ID is not set properly.

[0112] Second, when a flag indicates that all constituent rectangles have the same size, the number of rectangle rows and the number of rectangle columns may be inconsistent with the total number of constituent rectangles. In addition, the ranges of the number of rows and the number of columns are not specified.

[0113] Third, the ID of a constituent rectangle with the CR EMPTY type can only be inferred. However, the ID of constituent rectangles of other types can be signalled or inferred.

[0114] Fourth, there is no information to tell whether a constituent rectangle is a primary rectangle.

[0115] Fifth, a constituent rectangle may be associated with another constituent rectangle of the CR EMPTY type.

[0116] Sixth, the location of a constituent rectangle may be out of the picture range.

[0117] Seventh, the syntax elements for signalling of the associated ID and the group ID of a constituent rectangle may take too many bits.

[0118] Eighth, in the display overlays information SEI message, when doi_partition_flag is equal to 1, the partition ID specifies the display's constituent rectangle ID, which may cost many bits. It is also not consistent with the case when doi partition flag is equal to 0.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0119] Ninth, in the display overlays information SEI message, some display overlays may be overlapped. For example, when doi_nuh_layer_id[ i ] is equal to doi_nuh_layer_id[ j ] and doi_partition_idx[ i ] is equal to doi_partition_idx[ j ], displays i and j are the same, while they cannot convey different data.

[0120] Tenth, in the display overlays information SEI message, a display overlay may refer to a constituent rectangle with the type CR EMPTY. However, that constituent rectangle shall not be used.5. A listing of solutions and embodiments

[0121] To address at least some of the above-described problems, methods as summarized below are disclosed. The aspects should be considered as examples to explain the general concepts and should not be interpreted in a narrow way. Furthermore, these examples can be applied individually or combined in any maimer.1) To address problem 1, one or more syntax elements are signalled to specify a related value of the bit length of a constituent rectangle ID and / or an associated rectangle ID and / or a group ID. a. In one example, a syntax element is signalled to specify the bit length of a constituent rectangle ID and / or an associated rectangle ID and / or a group ID of a rectangle minus 1. b. In one example, a syntax element is signalled to specify the difference between the bit length of a constituent rectangle ID and / or an associated rectangle ID and / or a group ID of a rectangle and the minimal bit length to represent M different constituent rectangles, where M is the total number of constituent rectangles indicated in the SEI message. i. Alternatively, M is the total number of non-empty (i.e., the rectangle type is not CR EMPTY) constituent rectangles indicated in the SEI message. ii. In one example, the minimal bit length to represent M different constituent rectangles may be Ceil( Log2( M ). iii. In one example, a syntax element cr rect id len delta, plus Ceil( Log2( cr num rects minusl + 1 ) specifies the length, in bits, of the cr_rect_id[ i ], cr associated rect id [ i ], and cr_rcct_group_id| i ] syntax elements.2) To address problem 2, one or more of the following aspects are specified: a. In one example, it is a requirement of bitstream conformance that the number of constituent rectangle rows times the number of constituent rectangle columns shall be equal to the total number of constituent rectangles indicated in the SEI message. b. Alternatively, it is a requirement of bitstream conformance that the number of constituent rectangle rows times the number of constituent rectangle columns shall be greater than or equal to the total number of constituent rectangles indicated in the SEI message. i. For constituent rectangles with index greater than or equal to the number of constituent rectangle rows times the number of constituent rectangle columns, their rectangle types are inferred to be CR EMPTY. c. In one example, a range shall be specified for the syntax element cr num cols minus 1.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) i. In one example, the range is aligned to cr num rects minusl. i.e. from 0 to 2A12 - 1, inclusive. ii. Alternatively, in one example, the syntax element is coded in the same format as cr num rects minusl, i.e. u(12). d. In one example, a range shall be specified for the syntax element cr num rows minus 1. i. In one example, the range is aligned to cr num rects minusl, i.e. from 0 to 2A12 - 1, inclusive. ii. Alternatively’, in one example, the syntax element is coded in the same format as cr num rects minusl, i.e. u(12). e. In one example, it is a requirement of bitstream conformance that at least one constituent rectangle shall not have the type CR EMPTY.3) To address problem 3, the ID of a constituent rectangle with the type CR EMPTY may be signalled in the SEI message. a. In one example, all constituent rectangles may have an ID signalled in the SEI message. b. In one example, alternatively, for a constituent rectangle with the type CR EMPTY. its ID may be inferred but cannot be used or referred to.4) To address problem 4, one or more syntax elements may be signalled to indicate whether a constituent rectangle is a primary rectangle or not. a. In one example, a flag may be signalled to indicate whether a constituent rectangle is a primary rectangle or not. b. In one example, whether a constituent rectangle is a primary rectangle or not may’ be derived from other syntax elements signalled. i. In one example, a constituent rectangle with the type CR EMPTY shall not be a primaryrec tangle. ii. In one example, a primary rectangle shall be of the type CR TEXTURE. c. In one example, for a constituent rectangle with the type CR EMPTY. those syntax elements are not needed to send, and the constituent rectangle is inferred to be a non-primary rectangle.5) To address problem 5, the associated ID of a constituent rectangle shall not refer to a constituent rectangle with the type CR EMPTY. a. In one example, in addition, the associated ID of a constituent rectangle shall refer to a primary rectangle. b. In one example, in addition, only for a non-primary rectangle, the associated ID of a constituent rectangle may be signalled.6) To address problem 6, one or more of the following constraints are imposed. a. The width of a constituent rectangle shall be greater than 0. b. The height of a constituent rectangle shall be greater than 0.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) c. A constituent rectangle shall be fully within the picture.7) To address problem 7, indices may be signalled to indicate the association and / or grouping relationship. a. In one example, an index may be signalled to indicate the associated constituent rectangle for the current constituent rectangle. b. In one example, an index may be signalled to indicate to which group the current constituent rectangle belongs.8) To address problem 8, in the display overlays information SEI message, the partition ID may be used to specify the constituent rectangle index but not the constituent rectangle ID. a. In one example, a syntax element is used to specify- the constituent rectangle index when doi_partition_type_flag indicates constituent rectangle. b. In one example, a syntax element is always used to specify the index regardless of the partition type.9) To address problem 9. in the display overlays information SEI message, a constraint is imposed for two different display overlays, so that when they have the same layer ID. they shall not have the same partition ID or partition index. a. In one example, it is specified that it is a requirement of bitstream conformance that, for any two different values of i and j in the range of 0 to doi_num_display_overlays_minus2 + 1, inclusive, when doi_nuh_layer_id[ i ] is equal to doi_nuh_layer_id[ j ], doi_partition_id[ i ] shall not be equal to doi_partition_id[ j ].10) To address problem 10, in the display overlays information SEI message, a constraint is imposed for a display overlay, so that when it refers to a constituent rectangle, that constituent rectangle shall not have the type CR EMPTY. a. In addition, a constituent rectangle with the type CR EMPTY shall not be referred to in any SEI messages including the bitdepth range information SEI message.6. Embodiments

[0122] Below are some example embodiments for the aspects summarized in section 5. Most relevant parts that have been added or modified are shown in double braces (i.e.. { {a}} indicates that 'a' is added), and some of the deleted parts are shown in triple brackets (i.e., [[[a]]] indicates that ‘a’ is deleted). There may be some other changes that are editorial in nature and thus not highlighted.6.1 Embodiment 1

[0123] This embodiment covers the aspects for items 1, l.a.8.40.1 Constituent rectangles SEI message syntaxAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)8.40.2 Constituent rectangles SEI message semantics cr rect id len{ { minus 1 plus 1 }} specifies the length, {{in bits,}} of the cr rect id[ i ], cr associated rect id [ i ], and cr_recfygroup_id[ i ] syntax elements, syntax elements.6.2 Embodiment 2

[0124] This embodiment covers the aspects for items 2, 2. a., 2.c, 2.c.i, 2.d, 2.d.i.8.40.2 Constituent rectangles SEI message semantics cr num cols minusl plus 1 and cr num rows minusl plus 1 specify the number of columns and rows, respective!}', of the constituent rectangle grid when cr rect same size flag equal to 1. {{The values of cr num cols minusl and cr num rows minusl shall be in the range of 0 to 4095, inclusive.}} The variable crNumCols is set equal to cr num cols minusl + 1.The variable crNumRows is set equal to cr num rows minusl + 1.{{It is a requirement of bitstream conformance that when cr rect same size flag is present and equal to 1, crNumCols * crNumRows shall be equal to cr num rects minus 1 + 1. }}6.3 Embodiment 3

[0125] This embodiment covers the aspects for items 3, 3. a.8.40.1 Constituent rectangles SEI message syntaxAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)6.4 Embodiment 4

[0126] This embodiment covers the aspects for items 4, 4.b, 4.b.ii„ 5, 5. a, 5.b.8.40.1 Constituent rectangles SEI message syntaxAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)8.40.2 Constituent rectangles SEI message semantics cr_associated_rect_id[ i ] indicates the ID of an associated primary rectangle of the i-th rectangle. The length of the syntax element is cr rect id len bits.{{The value of cr rect type idc of a primary rectangle shall be equal to 0.}}It is a requirement of bitstream conformance that {{when present, the value of} } cr associated rect id[ i J {{shall be}} equal {{to}} cr_rect_id[ j ] for [[[some]]] {{at least one} } value of j in 0 .. cr num rects minusl {{and cr_rect_type_idc[ j ] shall not be equal to 255. }}[[[When not present, the value of cr_associated_rect_id[ i ] is undefined.]]]6.5 Embodiment 5

[0127] This embodiment covers the aspects for items 6, 6. a, 6.b.8.40.2 Constituent rectangles SEI message semantics cr_rect_width_in_units_minusl [ i ] plus 1 and cr rect height in units minus 1 [ i ] plus 1, when present, indicate the width and height, respectively, of the i-th constituent rectangle in units. The length of the syntax elements are cr rect size len minusl + 1.The variables crRectTopLeftX[ i ] and crRectTopLeftY[ i ], representing the x and y location, respectively, and variables crRectWidth[ i ] and crRectHeight[ i ], representing the width and height, respectively, of the i-th constituent rectangle are derived as follows.If cr_subpics_partitioning_flag is equal to 0 and cr rect same size flag is equal to 0, the following applies:- The variable crRectTopLeftX[ i ] is set equal to cr_rect_top_left_in_units_x[ i ] * crUnitSize- The variable crRectTopLeftYf i ] is set equal to cr_rect_top_left_in_units_y[ i ] * crUnitSize- The variable crRectWidthf i ] is set equal to ( cr rect width in units minus 1 + 1 ) * crUnitSize- The variable crRectHeight[ i ] is set equal to ( cr rect height in units minus 1 + 1 ) * crUnitSizeOtherwise, if cr_subpics_partitioning_flag is equal to 1, the following applies:- The variable crRcctTopLcftXf i ] is set equal to SubPicTopLcftXf i ]- The variable crRectTopLeftYf i ] is set equal to SubPicTopLeftYf i ]- The variable crRectWidthf i ] is set equal to SubPicWidth[ i ]The variable crRectHeight[ i ] is set to equal to SubPicHeight[ i ]Otherwise (cr rect same size flag is equal to 1). the following applies:Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)The variable crRectTopLeftX[ i ] is set equal to (i % crNumCols ) * MaxPicWidth / crNumColsThe variable crRectTopLeftY[ i ] is set equal to (i / [[[crNumCols]]] {{crNumRows}} ) * MaxPicHeight / crNumRows- The variable crRectWidth [ i ] is set equal to MaxPicWidth / crNumCols- The variable crRectHeight [ i ] is set to equal to MaxPicHeight / crNumRowsWhen PicWidthlnLumaSamples is not equal to MaxPicWidth, the following applies:- crRectTopLeftXf i ] is set equal to (crRectTopLeftXf i ] * PicWidthlnLumaSamples + MaxPicWidth / 2 ) / MaxPicWidth- crRectWidthf i ] is set equal to (crRectWidthf i ] * PicWidthlnLumaSamples + MaxPicWidth / 2 ) / MaxPicWidthWhen PicHeightlnLumaSamples is not equal to MaxPicHeight, the following applies: crRectTopLeftY[ i ] is set equal to (crRectTopLeftY[ i ] * Pic[[[Width]]]{ {Height} JlnLumaSamplcs + MaxPicHeight / 2 ) / MaxPicHeight crRectHeightf i ] is set equal to (crRectHeight[ i ] * Pic[[[Width]]] { {Height} [InLumaSamples + MaxPicHeight / 2 ) / MaxPicHeightIt is a requirement of bitstream conformance that for each sample position (x, y) in the coded picture there shall be at most one rectangle,], for which both of the following conditions apply:- x is in (crRectTopLeftX[ j ] .. crRectTopLeftXf j ] + crRectWidth [ j ] - 1)- y is in (crRectTopLeftY[ j ] .. crRectTopLeftYf j ] + crRectHeight[ i ] - 1){{It is a requirement of bitstream conformance that crRectWidth} i ] and crRectHeight[ i ] shall both be greater than 0.It is a requirement of bitstream conformance that crRectTopLeftXf i ] + crRectWidth} i ] shall be less than or equal to MaxPicWidth, and crRectTopLeftYf i ] + crRectHeight[ i ] shall be less than or equal to MaxPicHeight.}} It is a requirement of bitstream conformance that crRectTopLeftXf i ] % SubWidthC shall be equal to 0, crRectTopLeftX [ i ] % SubHeightC shall be equal to 0, crRectWidth[ i ] % SubWidthC shall be equal to 0, and crRectHeight[ i ] % SubHeightC shall be equal to 0.6.6 Embodiment 6

[0128] This embodiment covers the aspects for items 8, 9, 10.8.43.2 Display overlays SEI message semantics doi_partition_id{{x}}[ i ], when present and doi partition typc flag equal to 1, specifies {{the constituent rectangle index}} that {{represents}} the texture component of the i-th display overlay [[[is represented by the j- th constituent rectangle when cr_rect_id[ j ] equal doi_partition_id[ i ] ]]]. doi_partition_id{{x}}[ i ], when present and doi partition typc flag equal to 0, specifics the subpicturc index of the texture component of the i-th display overlay. When not present, the value of doi_partition_idx[ i ] is inferred to be equal to 0.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)When doi partition typc _flag equal to 1, doi_partition_idx[ i ] shall be in the range of 0 ..to cr_num_rects_minusl [ doi_nuh_layer_id[ i ] ] - 1 {{, inclusive. The value of cr rect type idc of the constituent rectangle specified by doi_partition_idx[ i ] shall not be equal to 255.}} When doi_partition_type_flag is equal to 0, doi_partition_idx[ i ] shall be in the range of 0 ..to NumSubpics[ doi_nuh_layer_id[ i ] ] - 1 {{, inclusive.It is a requirement of bitstream conformance that, for any two different values of i and j in the range of 0 to doi num display overlay s_minus2 + 1, inclusive, when doi_nuh_layer_id[ i ] is equal to doi nuh lay er_id[ j ], doi_partition_idx[ i ] shall not be equal to doi_partition_idx[ j ].}}7. References[1] ITU-T and ISO / IEC, ‘‘High efficiency video coding”, Rec. ITU-T H.265 | ISO / IEC 23008-2 (in force edition).[2] Rec. ITU-T H.266 | ISO / IEC 23090-3, “Versatile Video Coding”, 2022.[3] Rec. ITU-T Rec. H.274 | ISO / IEC 23002-7, “Versatile Supplemental Enhancement Information Messages for Coded Video Bitstreams”, 2023.[4] S. McCarthy, J. Boyce. J. Chen, S. Deshpande, M. M. Hannuksela. H. Tan, Y.-K. Wang (editors),“Technologies under consideration for future extensions of VSEI (version 5).” JVET output document JVET- AI2032, public!}' available online herein: https: / / jvet- experts . org / doc_end_user / documents / 35_Sapporo / wg 11 / JVET - AI2032-v2. zip

[0129] FIG. 1 is a block diagram showing an example video processing system 4000 in which various embodiments disclosed herein may7be implemented. Various implementations may include some or all of the components of the system 4000. The system 4000 may include input 4002 for receiving video content. The video content may’ be received in a raw or uncompressed format, c.g., 8- or 10-bit multi-component pixel values, or may’ be in a compressed or encoded format. The input 4002 may represent a network interface, a peripheral bus interface, or a storage interface. Examples of network interface include wired interfaces such as Ethernet, passive optical network (PON), etc. and wireless interfaces such as Wi-Fi or cellular interfaces.

[0130] The system 4000 may include a coding component 4004 that may implement the various coding or encoding methods described in the present disclosure. The coding component 4004 may reduce the average bitrate of video from the input 4002 to the output of the coding component 4004 to produce a coded representation of the video. The coding techniques are therefore sometimes called video compression or video transcoding techniques. The output of the coding component 4004 may be either stored, or transmitted via a communication connected, as represented by the component 4006. The stored or communicated bitstream (or coded) representation of the video received at the input 4002 may be used by a component 4008 for generating pixel values or displayable video that is sent to a display interface 4010. The process of generating user- viewable video from the bitstream representation is sometimes called video decompression. Furthermore, while certain video processing operations are referred to as “coding” operations or tools, it will be appreciated that the coding tools or operations are used at an encoder and corresponding decoding tools or operations that reverse the results of the coding will be performed by a decoder.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0131] Examples of a peripheral bus interface or a display interface may include universal serial bus (USB) or high definition multimedia interface (HDMI) or DisplayPort, and so on. Examples of storage interfaces include serial advanced technology attachment (SATA), peripheral component interconnect (PCI), integrated drive electronics (IDE) interface, and the like. The embodiments described in the present disclosure may be embodied in various electronic devices such as mobile phones, laptops, smartphones or other devices that are capable of performing digital data processing and / or video display.

[0132] FIG. 2 is a block diagram of an example video processing apparatus 4100. The apparatus 4100 may be used to implement one or more of the methods described herein. The apparatus 4100 may be embodied in a smartphone, tablet, computer, Internet of Things (loT) receiver, and so on. The apparatus 4100 may include one or more processors 4102, one or more memories 4104 and video processing circuitry 4106. The processor(s) 4102 may be configured to implement one or more methods described in the present disclosure. The memory (memories) 4104 may be used for storing data and code used for implementing the methods and embodiments described herein. The video processing circuitry 4106 may be used to implement, in hardware circuitry, some embodiments described in the present disclosure. In some embodiments, the video processing circuitry 4106 may be at least partly included in the processor 4102, e.g., a graphics co-processor.

[0133] FIG. 3 is a flowchart for an example method 4200 of video processing. The method 4200 determines one or more syntax elements signalled to specify a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID at step 4202. A conversion is performed between a visual media data and a bitstream based on one or more syntax elements at step 4204. The conversion may include encoding at an encoder, decoding at a decoder, or combinations thereof.

[0134] It should be noted that the method 4200 can be implemented in an apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, such as video encoder 4400, video decoder 4500, and / or encoder 4600. In such a case, the instructions upon execution by the processor, cause the processor to perform the method 4200. Further, the method 4200 can be performed by a non-transitory computer readable medium comprising a computer program product for use by a video coding device. The computer program product comprises computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method 4200.

[0135] FIG. 4 is a block diagram that illustrates an example video coding system 4300 that may utilize the embodiments of this disclosure. The video coding system 4300 may include a source device 4310 and a destination device 4320. Source device 4310 generates encoded video data which may be referred to as a video encoding device. Destination device 4320 may decode the encoded video data generated by source device 4310 which may be referred to as a video decoding device.

[0136] Source device 4310 max' include a video source 4312, a video encoder 4314, and an input / output (I / O) interface 4316. Video source 4312 may include a source such as a video capture device, an interface to receive video data from a video content provider, and / or a computer graphics system for generating video data, or aAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) combination of such sources. The video data may comprise one or more pictures. Video encoder 4314 encodes the video data from video source 4312 to generate a bitstream. The bitstream may include a sequence of bits that form a coded representation of the video data. The bitstream may include coded pictures and associated data. The coded picture is a coded representation of a picture. The associated data may include sequence parameter sets, picture parameter sets, and other syntax structures. I / O interface 4316 may include a modulator / demodulator (modem) and / or a transmitter. The encoded video data may be transmitted directly to destination device 4320 via I / O interface 4316 through network 4330. The encoded video data may also be stored onto a storage medium / server 4340 for access by destination device 4320.

[0137] Destination device 4320 may include an I / O interface 4326, a video decoder 4324, and a display device 4322. I / O interface 4326 may include a receiver and / or a modem. I / O interface 4326 may acquire encoded video data from the source device 4310 or the storage medium / server 4340. Video decoder 4324 may decode the encoded video data. Display device 4322 may display- the decoded video data to a user. Display device 4322 maybe integrated with the destination device 4320, or may be external to destination device 4320, which can be configured to interface with an external display device.

[0138] Video encoder 4314 and video decoder 4324 may operate according to a video compression standard, such as the High Efficiency Video Coding (HEVC) standard, Versatile Video Coding (WC) standard and other current and / or further standards.

[0139] FIG. 5 is a block diagram illustrating an example of video encoder 4400, which may be video encoder 4314 in the system 4300 illustrated in FIG. 4. Video encoder 4400 may be configured to perform any or all of the embodiments of this disclosure. The video encoder 4400 includes a plurality of functional components. The embodiments described in this disclosure may- be shared among the various components of video encoder 4400. In some examples, a processor may be configured to perform any or all of the embodiments described in this disclosure.

[0140] The functional components of video encoder 4400 may include a partition unit 4401 ; a prediction unit 4402, which may include a mode select unit 4403, a motion estimation unit 4404, a motion compensation unit 4405, and an intra prediction unit 4406; a residual generation unit 4407; a transform processing unit 4408; a quantization unit 4409; an inverse quantization unit 4410; an inverse transform unit 4411; a reconstruction unit 4412; a buffer 4413; and an entropy encoding unit 4414.

[0141] In other examples, video encoder 4400 may include more, fewer, or different functional components. In an example, prediction unit 4402 may include an intra block copy (IBC) unit. The IBC unit may perform prediction in an IBC mode in which at least one reference picture is a picture where the current video block is located.

[0142] Furthermore, some components, such as motion estimation unit 4404 and motion compensation unit 4405 may be highly integrated, but are represented in the example of video encoder 4400 separately for purposes of explanation.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0143] Partition unit 4401 may partition a picture into one or more video blocks. Video encoder 4400 and video decoder 4500 may support various video block sizes.

[0144] Mode select unit 4403 may select one of the coding modes, intra or inter, e.g., based on error results, and provide the resulting intra or inter coded block to a residual generation unit 4407 to generate residual block data and to a reconstruction unit 4412 to reconstruct the encoded block for use as a reference picture. In some examples, mode select unit 4403 may select a combination of intra and inter prediction (CUP) mode in which the prediction is based on an inter prediction signal and an intra prediction signal. Mode select unit 4403 may also select a resolution for a motion vector (e.g., a sub-pixel or integer pixel precision) for the block in the case of inter prediction.

[0145] To perform inter prediction on a current video block, motion estimation unit 4404 may generate motion information for the current video block by comparing one or more reference frames from buffer 4413 to the current video block. Motion compensation unit 4405 may determine a predicted video block for the current video block based on the motion information and decoded samples of pictures from buffer 4413 other than the picture associated with the current video block.

[0146] Motion estimation unit 4404 and motion compensation unit 4405 may perform different operations for a current video block, for example, depending on whether the current video block is in an I slice, a P slice, or a B slice.

[0147] In some examples, motion estimation unit 4404 may perform uni-directional prediction for the current video block, and motion estimation unit 4404 may search reference pictures of list 0 or list 1 for a reference video block for the current video block. Motion estimation unit 4404 may then generate a reference index that indicates the reference picture in list 0 or list 1 that contains the reference video block and a motion vector that indicates a spatial displacement between the current video block and the reference video block. Motion estimation unit 4404 may output the reference index, a prediction direction indicator, and the motion vector as the motion information of the current video block. Motion compensation unit 4405 may generate the predicted video block of the current block based on the reference video block indicated by the motion information of the current video block.

[0148] In other examples, motion estimation unit 4404 may perform bi-directional prediction for the current video block, motion estimation unit 4404 may search the reference pictures in list 0 for a reference video block for the current video block and may also search the reference pictures in list 1 for another reference video block for the current video block. Motion estimation unit 4404 may then generate reference indexes that indicate the reference pictures in list 0 and list 1 containing the reference video blocks and motion vectors that indicate spatial displacements between the reference video blocks and the current video block. Motion estimation unit 4404 may output the reference indexes and the motion vectors of the current video block as the motion information of the current video block. Motion compensation unit 4405 may generate the predicted video block of the current video block based on the reference video blocks indicated by the motion information of the current video block.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0149] In some examples, motion estimation unit 4404 may output a full set of motion information for decoding processing of a decoder. In some examples, motion estimation unit 4404 may not output a full set of motion information for the current video. Rather, motion estimation unit 4404 may signal the motion information of the current video block with reference to the motion information of another video block. For example, motion estimation unit 4404 may determine that the motion information of the current video block is sufficiently similar to the motion information of a neighboring video block.

[0150] In one example, motion estimation unit 4404 may indicate, in a syntax structure associated with the current video block, a value that indicates to the video decoder 4500 that the current video block has the same motion information as another video block.

[0151] In another example, motion estimation unit 4404 may identify, in a syntax structure associated with the current video block, another video block and a motion vector difference (MVD). The motion vector difference indicates a difference between the motion vector of the current video block and the motion vector of the indicated video block. The video decoder 4500 may use the motion vector of the indicated video block and the motion vector difference to determine the motion vector of the current video block.

[0152] As discussed above, video encoder 4400 may predictively signal the motion vector. Two examples of predictive signaling techniques that may' be implemented byrvideo encoder 4400 include advanced motion vector prediction (AMVP) and merge mode signaling.

[0153] Intra prediction unit 4406 may perform intra prediction on the current video block. When intra prediction unit 4406 performs intra prediction on the current video block, intra prediction unit 4406 may generate prediction data for the current video block based on decoded samples of other video blocks in the same picture. The prediction data for the current video block may include a predicted video block and various syntax elements.

[0154] Residual generation unit 4407 may generate residual data for the current video block by subtracting the predicted video block(s) of the current video block from the current video block. The residual data of the current video block may include residual video blocks that correspond to different sample components of the samples in the current video block.

[0155] In other examples, there may be no residual data for the current video block for the current video block, for example in a skip mode, and residual generation unit 4407 may not perform the subtracting operation.

[0156] Transform processing unit 4408 may generate one or more transform coefficient video blocks for the current video block by' applying one or more transfonns to a residual video block associated with the current video block.

[0157] After transform processing unit 4408 generates a transform coefficient video block associated with the current video block, quantization unit 4409 may quantize the transform coefficient video block associated with the current video block based on one or more quantization parameter (QP) values associated with the current video block.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0158] Inverse quantization unit 4410 and inverse transform unit 4411 may apply inverse quantization and inverse transforms to the transform coefficient video block, respectively, to reconstruct a residual video block from the transform coefficient video block. Reconstruction unit 4412 may add the reconstructed residual video block to corresponding samples from one or more predicted video blocks generated by the prediction unit 4402 to produce a reconstructed video block associated with the current block for storage in the buffer 4413.

[0159] After reconstruction unit 4412 reconstructs the video block, the loop filtering operation may be performed to reduce video blocking artifacts in the video block.

[0160] Entropy encoding unit 4414 may receive data from other functional components of the video encoder 4400. When entropy encoding unit 4414 receives the data, entropy encoding unit 4414 may perform one or more entropy encoding operations to generate entropy encoded data and output a bitstream that includes the entropy encoded data.

[0161] FIG. 6 is a block diagram illustrating an example of video decoder 4500 which may be video decoder 4324 in the system 4300 illustrated in FIG. 4. The video decoder 4500 may be configured to perform any or all of the embodiments of this disclosure. In the example shown, the video decoder 4500 includes a plurality of functional components. The embodiments described in this disclosure may be shared among the various components of the video decoder 4500. In some examples, a processor may be configured to perform any or all of the embodiments described in this disclosure.

[0162] In the example shown, video decoder 4500 includes an entropy decoding unit 4501, a motion compensation unit 4502, an intra prediction unit 4503, an inverse quantization unit 4504, an inverse transformation unit 4505, a reconstruction unit 4506, and a buffer 4507. Video decoder 4500 may, in some examples, perform a decoding pass generally reciprocal to the encoding pass described with respect to video encoder 4400.

[0163] Entropy decoding rmit 4501 may retrieve an encoded bitstream. The encoded bitstream may include entropy coded video data (e.g., encoded blocks of video data). Entropy decoding unit 4501 may decode the entropy coded video data, and from the entropy decoded video data, motion compensation unit 4502 may determine motion information including motion vectors, motion vector precision, reference picture list indexes, and other motion information. Motion compensation unit 4502 may, for example, determine such information by performing the AMVP and merge mode.

[0164] Motion compensation rmit 4502 may produce motion compensated blocks, possibly performing interpolation based on interpolation filters. Identifiers for interpolation filters to be used with sub-pixel precision may be included in the syntax elements.

[0165] Motion compensation unit 4502 may use interpolation filters as used by video encoder 4400 during encoding of the video block to calculate interpolated values for sub-integer pixels of a reference block. Motion compensation unit 4502 may detennine the interpolation filters used by video encoder 4400 according to received syntax information and use the interpolation filters to produce predictive blocks.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0166] Motion compensation unit 4502 may use some of the syntax information to determine sizes of blocks used to encode frame(s) and / or slice(s) of the encoded video sequence, partition information that describes how each macroblock of a picture of the encoded video sequence is partitioned, modes indicating how each partition is encoded, one or more reference frames (and reference frame lists) for each inter coded block, and other information to decode the encoded video sequence.

[0167] Intra prediction unit 4503 may use intra prediction modes for example received in the bitstream to form a prediction block from spatially adjacent blocks. Inverse quantization unit 4504 inverse quantizes, i.e., dequantizes, the quantized video block coefficients provided in the bitstream and decoded by entropy decoding unit 4501. Inverse transform unit 4505 applies an inverse transform.

[0168] Reconstruction unit 4506 may sum the residual blocks with the corresponding prediction blocks generated by motion compensation unit 4502 or intra prediction unit 4503 to form decoded blocks. If desired, a deblocking filter may also be applied to filter the decoded blocks in order to remove blockiness artifacts. The decoded video blocks are then stored in buffer 4507, which provides reference blocks for subsequent motion compensation / intra prediction and also produces decoded video for presentation on a display device.

[0169] FIG. 7 is a schematic diagram of an example encoder 4600. The encoder 4600 is suitable for implementing the techniques of WC. The encoder 4600 includes three in-loop filters, namely a deblocking filter (DF) 4602, a sample adaptive offset (SAG) 4604, and an adaptive loop filter (ALF) 4606. Unlike the DF 4602, which uses predefined filters, the SAG 4604 and the ALF 4606 utilize the original samples of the current picture to reduce the mean square errors between the original samples and the reconstructed samples by adding an offset and by applying a finite impulse response (FIR) filter, respectively', with coded side information signaling the offsets and filter coefficients. The ALF 4606 is located at the last processing stage of each picture and can be regarded as a tool trying to catch and fix artifacts created by the previous stages.

[0170] The encoder 4600 further includes an intra prediction component 4608 and a motion estimation / compensation (ME / MC) component 4610 configmed to receive input video. The intra prediction component 4608 is configmed to perform intra prediction, while the ME / MC component 4610 is configmed to utilize reference pictures obtained from a reference picture buffer 4612 to perform inter prediction. Residual blocks from inter prediction or intra prediction are fed into a transform (T) component 4614 and a quantization (Q) component 4616 to generate quantized residual transform coefficients, which are fed into an entropy coding component 4618. The entropy coding component 4618 entropy codes the prediction results and the quantized transform coefficients and transmits the same toward a video decoder (not shown). Quantization components output from the quantization component 4616 may be fed into an inverse quantization (IQ) components 4620, an inverse transform component 4622, and a reconstruction (REC) component 4624. The REC component 4624 is able to output images to the DF 4602, the SAG 4604, and the ALF 4606 for filtering prior to those images being stored in the reference picture buffer 4612.

[0171] A listing of solutions preferred by some examples is provided next.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0172] The following solutions show examples of embodiments discussed herein.

[0173] 1. A method for processing media data comprising: determining one or more syntax elements signalled to specify a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; and performing a conversion between a visual media data and a bitstream based on the one or more syntax elements.

[0174] 2. The method of solution 1, wherein the syntax elements are signalled to specify’ the bit length of constituent rectangle ID, the associated rectangle ID, or the group ID of a rectangle minus 1.

[0175] 3. The method of any of solutions 1-2, wherein a syntax element is signalled to specify a difference between the bit length of a constituent rectangle ID. the associated rectangle ID, or the group ID of a rectangle and a minimal bit length to represent M different constituent rectangles, where M is a total number of constituent rectangles indicated in a supplemental enhancement information (SEI) message.

[0176] 4. The method of any of solutions 1-3, wherein M is the total number of non-empty constituent rectangles indicated in the SEI message where a rectangle type is not CR EMPTY.

[0177] 5. The method of any of solutions 1-4, wherein a minimal bit length to represent M different constituent rectangles is Ceil( Log2( M ).

[0178] 6. The method of any of solutions 1-5, wherein a syntax element cr rect id len delta, plusCeil( Log2( cr num rects minusl + 1 ) specifies a length, in bits, of cr_rect_id[ i ], cr associated rect id [ i ], and cr_rcct_group_id| i ] syntax elements.

[0179] 7. The method of any of solutions 1-6, wherein bitstream conformance requires that a number of constituent rectangle rows times a number of constituent rectangle columns shall be equal to a total number of constituent rectangles indicated in the SEI message.

[0180] 8. The method of any of solutions 1-7. wherein bitstream conformance requires that the number of constituent rectangle rows times the number of constituent rectangle columns shall be greater than or equal to the total number of constituent rectangles indicated in the SEI message, or wherein for constituent rectangles with index greater than or equal to the number of constituent rectangle rows times the number of constituent rectangle columns, their rectangle types are inferred to be CR EMPTY.

[0181] 9. The method of any of solutions 1-8, wherein a range shall be specified for the syntax element cr num cols minusl, or wherein the range is aligned to cr num rects ininus I , from 0 to 2A12 - 1, inclusive, or wherein the syntax element is coded as u(12).

[0182] 10. The method of any of solutions 1-9, wherein a range shall be specified for the syntax element cr num rows minusl, or wherein the range is aligned to cr num rects minusl, from 0 to 2A12 - 1, inclusive, or wherein the syntax element is coded as u(12).

[0183] 11. The method of any of solutions 1-10. wherein bitstream conformance requires that at least one constituent rectangle shall not have the type CR EMPTY.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0184] 12. The method of any of solutions 1-11, wherein the ID of a constituent rectangle with the typeCR EMPTY is signalled in the SEI message.

[0185] 13. The method of any of solutions 1-12, wherein all constituent rectangles have an ID signalled in the SEI message, or wherein for a constituent rectangle with the type CR EMPTY, the constituent rectangle ID is inferred but cannot be used or referred to.

[0186] 14. The method of any of solutions 1-13, wherein one or more syntax elements are signalled to indicate whether a constituent rectangle is a primary rectangle or not.

[0187] 15. The method of any of solutions 1-14, wherein a flag is signalled to indicate whether a constituent rectangle is a primary rectangle or not. or wherein whether a constituent rectangle is a primary rectangle or not is derived from other syntax elements signaled, or wherein a constituent rectangle with the type CR EMPTY shall not be a primary rectangle, or wherein a primary rectangle shall be of the type CR TEXTURE, or wherein for a constituent rectangle with the type CR EMPTY, those syntax elements are not needed to send, and the constituent rectangle is inferred to be a non-primary rectangle.

[0188] 16. The method of any of solutions 1-1 , wherein the associated ID of a constituent rectangle shall not refer to a constituent rectangle with the type CR EMPTY.

[0189] 17. The method of any of solutions 1-16, wherein the associated ID of a constituent rectangle shall refer to a primary rectangle, or wherein only for a non-primary rectangle, the associated ID of a constituent rectangle is signalled.

[0190] 18. The method of any of solutions 1-17, wherein a width of a constituent rectangle shall be greater than 0, or wherein a height of a constituent rectangle shall be greater than 0, or wherein a constituent rectangle shall be fully within the picture.

[0191] 19. The method of any of solutions 1-18, wherein indices are signalled to indicate an association or grouping relationship.

[0192] 20. The method of any of solutions 1-19, wherein an index is signalled to indicate the associated constituent rectangle for the current constituent rectangle, or wherein an index is signalled to indicate to which group the current constituent rectangle belongs.

[0193] 21. The method of any of solutions 1-20, wherein in the display overlays information SEI message, the partition ID is used to specify the constituent rectangle index but not the constituent rectangle ID.

[0194] 22. The method of any of solutions 1-21, wherein a syntax element is used to specify the constituent rectangle index when doi_partition_type_flag indicates constituent rectangle, or wherein a syntax element is always used to specify the index regardless of the partition type.

[0195] 23. The method of any of solutions 1-22, wherein in the display overlays information SEI message, a constraint is imposed for two different display overlays, so that when they have the same layer ID, they shall not have the same partition ID or partition index.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)

[0196] 24. The method of any of solutions 1-23, wherein bitstream conformance requires that, for any two different values of i and j in the range of 0 to doi_num_display_overlays_minus2 + 1, inclusive, when doi_nuh_layer_id[ i ] is equal to doi_nuh_la er_id| j ], doi_partition_id[ i ] shall not be equal to doi_partition_id[ j ]•

[0197] 25. The method of any of solutions 1-24, wherein in the display7overlays information SEI message, a constraint is imposed for a display overlay, so that when the display7overlay refers to a constituent rectangle, that constituent rectangle shall not have the type CR EMPTY.

[0198] 26. The method of any of solutions 1-25, wherein a constituent rectangle with the type CR EMPTY shall not be referred to in any SEI messages including the bitdepth range information SEI message.

[0199] 27. 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 the method of any of solutions 1-26.

[0200] 28. 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 perform the method of any of solutions 1-26.

[0201] 29. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining one or more syntax elements signalled to specify- a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; and generating a bitstream based on the determining.

[0202] 30. A method for storing bitstream of a video comprising: determining one or more syntax elements signalled to specify a related value of the bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; generating a bitstream based on the determining; and storing the bitstream in a non-transitory computer-readable recording medium.

[0203] 31. A method, apparatus, or system described in the present disclosure.

[0204] In the solutions described herein, an encoder may conform to the format rule by producing a coded representation according to the format rule. In the solutions described herein, a decoder may use the format rule to parse sy ntax elements in the coded representation with the knowledge of presence and absence of syntax elements according to the format rule to produce decoded video.

[0205] In the present disclosure, the term “video processing'’ may refer to video encoding, video decoding, video compression or video decompression. For example, video compression algorithms may be applied during conversion from pixel representation of a video to a corresponding bitstream representation or vice versa. The bitstream representation of a current video block may, for example, correspond to bits that are either co-located or spread in different places within the bitstream, as is defined by the syntax. For example, a macroblock may be encoded in terms of transformed and coded error residual values and also using bits in headers and other fields inAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) the bitstream. Furthermore, dining conversion, a decoder may parse a bitstream with the knowledge that some fields may be present, or absent, based on the determination, as is described in the above solutions. Similarly, an encoder may determine that certain syntax fields are or are not to be included and generate the coded representation accordingly by including or excluding the syntax fields from the coded representation.

[0206] The disclosed and other solutions, examples, embodiments, modules and the functional operations described in this disclosure can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this disclosure and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term ‘‘data processing apparatus’’ encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machinegenerated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.

[0207] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g.. one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0208] The processes and logic flows described in this disclosure can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry', e.g., a field-programmable gate array' (FPGA) or an applicationspecific integrated circuit (ASIC).

[0209] Processors suitable for the execution of a computer program include, by w ay of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random-access memory or both. TheAtty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory', media and memory' devices, including by way of example semiconductor memory devices, e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory' (EEPROM), and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and compact disc read-only memory (CD ROM) and Digital versatile disc-read only memory (DVD-ROM) disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0210] While the present disclosure contains many specifics, these should not be construed as limitations on the scope of any subject matter or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of the present disclosure. Certain features that are described in the present disclosure in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately' or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0211] Similarly', while operations arc depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in the present disclosure should not be understood as requiring such separation in all embodiments.

[0212] Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in the present disclosure.

[0213] A first component is directly coupled to a second component when there are no intervening components, except for a line, a trace, or another medium between the first component and the second component. The first component is indirectly coupled to the second component when there are intervening components other than a line, a trace, or another medium between the first component and the second component. The term “coupled” and its variants include both directly' coupled and indirectly' coupled. The use of the term “about” means a range including ±10% of the subsequent number unless otherw ise stated.

[0214] While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of tire present disclosure. The present examples are to be considered as illustrative and not restrictive,Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W) and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.

[0215] In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled may be directly connected or may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.

Claims

Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)CLAIMSWhat is claimed is:1 . A method for processing visual media data, comprising: determining one or more syntax elements signalled to specify a related value of a bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID: and performing a conversion between a visual media data and a bitstream based on the one or more syntax elements.

2. The method of claim 1, wherein bitstream conformance requires that a number of constituent rectangle rows times a number of constituent rectangle columns shall be equal to a total number of constituent rectangles indicated in a supplemental enhancement information (SEI) message.

3. The method of claim 1, wherein bitstream conformance requires that a number of constituent rectangle rows times a number of constituent rectangle columns shall be greater than or equal to a total number of constituent rectangles indicated in a supplemental enhancement information (SEI) message.

4. The method of any of claims 1-3, wherein rectangle types are inferred to be CR EMPTY for constituent rectangles with an index greater than or equal to the number of constituent rectangle rows times the number of constituent rectangle columns.

5. The method of any of claims 1-4, wherein a range shall be specified for a syntax element cr num cols minus 1.

6. The method of any of claims 1-5, wherein the range for cr num cols minus 1 is aligned to cr num rects minusl, from 0 to 2A12 - 1, inclusive.

7. The method of any of claims 1-6, wherein cr num cols minusl is coded as u(12).

8. The method of any of claims 1-7, w'herein a range shall be specified for a syntax element cr num rows minus 1.

9. The method of any' of claims 1-8, wherein the range for cr num rows minus 1 is aligned to cr num rects minusl, from 0 to 2A12 - 1, inclusive.

10. The method of any of claims 1-9, wherein cr num row s minus 1 is coded as u(12).Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)11. The method of any of claims 1-10, wherein one or more syntax elements are signalled to indicate whether a constituent rectangle is a primary rectangle.

12. The method of any of claims 1-11, wherein a flag is signalled to indicate whether a constituent rectangle is a primary rectangle.

13. The method of any of claims 1-12, wherein whether a constituent rectangle is a primary rectangle is derived from other syntax elements signaled.

14. The method of any of claims 1-13, wherein a constituent rectangle with the rectangle type CR EMPTY shall not be a primary rectangle.

15. The method of any of claims 1-14, wherein a primary rectangle shall be of the rectangle type CR TEXTURE.

16. The method of any of claims 1-15, wherein a constituent rectangle with the rectangle type CR EMPTY is inferred to be a non-primary rectangle.

17. The method of any of claims 1-16, wherein a width of a constituent rectangle shall be greater than 0.

18. The method of any of claims 1-17, wherein a height of a constituent rectangle shall be greater than 0.

19. The method of any of claims 1-18, wherein a constituent rectangle shall be fully within a picture.

20. The method of any of claims 1-19, wherein indices are signalled to indicate an association or grouping relationship of consistent rectangles.

21. The method of any' of claims 1-20, wherein an index is signalled to indicate an associated constituent rectangle for a current constituent rectangle, or wherein an index is signalled to indicate to which group the current constituent rectangle belongs.

22. The method of any of claims 1-21, wherein in a display overlays information (DOI) SEI message, a constraint is imposed for a display' overlay, such that when the display overlay refers to a constituent rectangle, that constituent rectangle shall not have the rectangle type CR EMPTY.Atty. Dkt. No.: 4824-70304 (P24092456901WO2; G25N20992W)23. The method of any of claims 1-22, wherein a constituent rectangle with the rectangle type CR EMPTY shall not be referred to in any SEI messages including a bitdepth range information SEI message.

24. The method of any of claims 1-23, wherein the conversion includes encoding the visual media data into the bitstream.

25. The method of any of claims 1-23, wherein the conversion includes decoding the visual media data from the bitstream.

26. 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 the method of any of claims 1-25.

27. 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 perform the method of any of claims 1-25.

28. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining one or more syntax elements signalled to specify a related value of a bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID; and generating a bitstream based on the determining.

29. A method for storing bitstream of a video, comprising: determining one or more syntax elements signalled to specify a related value of a bit length of a constituent rectangle identifier (ID), an associated rectangle ID, or a group ID: generating a bitstream based on the determining; and storing the bitstream in a non-transitory computer-readable recording medium.

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