Signaling of post-processing filter banks for processing sequential SEI messages using SEI

Abstract

A mechanism for processing video data is disclosed. The mechanism includes determining to signal a syntax element with an identification number or name poid in a SEI processing order SEI message to identify a set of SEI message types for which a preferred processing order is indicated in the SEI processing order SEI message. A conversion between the visual media data and the bitstream is performed based on the syntax element.

Description

Signaling using the post-processing filter bank for sequential SEI messages.

[0001] Cross-references to related applications

[0002] This patent application claims the benefit of U.S. Patent Application No. 63 / 588,267, filed October 5, 2023, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to the generation, storage, and use of digital audio and video media information in file formats. Background Technology

[0004] Digital video accounts for the largest share of 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 is likely to continue to grow. Summary of the Invention

[0005] The first aspect relates to a method for processing media data, comprising: determining a Supplemental Enhancement Information (SEI) Processing Order (SPO) SEI message including a syntax element, wherein the syntax element contains an identifier to identify the SPO SEI message; and performing a conversion between visual media data and a bitstream based on the syntax element.

[0006] Alternatively, in any of the above aspects, another implementation of that aspect provides that the SPO SEI message carries information indicating a preferred processing order of a set of SEI message types in the encoded video sequence.

[0007] Alternatively, in any of the above aspects, another implementation of that aspect provides that the syntax element is specified as po_id.

[0008] Alternatively, in any of the above aspects, another implementation of that aspect provides that: only one SEI message type indication within the SPO SEI message is allowed to indicate a post-processing filter for interpolating the image at application time.

[0009] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides: allowing only the last SEI message type indication within the SPO SEI message to perform a post-processing filter for interpolating the image at application time.

[0010] Alternatively, in any of the above aspects, another implementation of that aspect provides a preferred processing order for a post-processing filter (PPF) that interpolates the image at application time without explicitly transmitting signals in the bitstream.

[0011] Alternatively, in any of the above aspects, another embodiment of that aspect provides that the preferred processing order of PPFs for interpolating images during application is presumed to be the penultimate PPF indication order plus one.

[0012] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides that: po_last_ppf_picture_interpolation_flag is added outside the following loop:

[0013] for( i = 0, i < po_num_sei_messages_minus2 + 2; i++),

[0014] The po_last_ppf_picture_interpolation_flag indicates the last SEI message type in the SPO SEI message, which indicates the PFF that interpolates the image at the time of application.

[0015] Alternatively, in any of the above aspects, another implementation of that aspect provides: po_sei_processing_order[i] conditional as follows:

[0016] if( ( i < po_num_sei_messages_minus2 + 1 ) || !po_last_ppf_picture_interpolation_flag),

[0017] The number of SEI messages with the processing order indicated in the SPO SEI message is po_num_sei_messages_minus2.

[0018] Alternatively, in any of the above aspects, another implementation of that aspect provides that the value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to the value of po_sei_processing_order[ po_num_sei_messages_minus2 ] plus 1.

[0019] Alternatively, in any of the above aspects, another implementation of that aspect provides that: the po_last_ppf_picture_interpolation_flag is not transmitted via signal in the bitstream.

[0020] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides that the variable PoLastPpfPictureInterpolationFlag is derived based on the SEI payloadType and the SEI prefix indication of the last entry (if present), wherein the SEI prefix indicates whether the last PPF interpolates the image when applied.

[0021] Alternatively, in any of the above aspects, another implementation of that aspect provides: po_sei_processing_order[i] conditional as follows:

[0022] if( ( i < po_num_sei_messages_minus2 + 1 ) || !PoLastPpfPictureInterpolationFlag),

[0023] The number of SEI messages with the processing order indicated in the SPO SEI message is po_num_sei_messages_minus2.

[0024] Alternatively, in any of the above aspects, another implementation of that aspect provides that the value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to the value of po_sei_processing_order[ po_num_sei_messages_minus2 ] plus 1.

[0025] Alternatively, in any of the above aspects, another implementation of that aspect provides that the value of the syntax element minus 1 specifies the amount of data associated with the i-th SEI message processed according to the preferred processing order identified in the SPO SEI message.

[0026] Alternatively, in any of the above aspects, another implementation of that aspect provides that the data volume includes bytes or bits.

[0027] Alternatively, in any of the above aspects, another implementation of the aspect provides that the syntax element is specified as po_num_bits_in_prefix_indication_minus1[i].

[0028] Alternatively, in any of the above aspects, another implementation of that aspect provides that the value of the syntax element specifies the amount of data associated with the i-th SEI message processed according to the preferred processing order identified in the SPO SEI message.

[0029] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides that the SPO SEI message does not include the SEI prefix flag to indicate the presence of a syntax element.

[0030] Alternatively, in any of the above aspects, another implementation of that aspect provides that the prefix is ​​unavailable when the syntax element has a zero value.

[0031] Alternatively, in any of the above aspects, another implementation of the aspect provides that when a syntax element is not present in the bitstream, the syntax element is presumed to have a zero value.

[0032] Alternatively, in any of the above aspects, another implementation of that aspect provides that the conversion includes encoding media data into a bitstream.

[0033] Alternatively, in any of the above aspects, another implementation of that aspect provides that the conversion includes decoding media data from a bitstream.

[0034] The second aspect relates to an apparatus for processing video data, including a processor and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform the methods of any of the disclosed embodiments.

[0035] The third aspect relates to a non-transitory computer-readable medium including a computer program product for use by a video codec apparatus, the computer program product including computer-executable instructions stored on the non-transitory computer-readable medium, causing the video codec apparatus to perform any of the methods of the disclosed embodiments when executed by a processor.

[0036] The fourth aspect relates to a non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by a video processing apparatus, wherein the method includes: determining a Supplemental Enhancement Information (SEI) Processing Order (SPO) SEI message comprising a syntax element, wherein the syntax element contains an identifier to identify the SPO SEI message; and performing a conversion between visual media data and the bitstream based on the syntax element.

[0037] The fifth aspect relates to a method for storing a bitstream of video, comprising: determining a Supplemental Enhancement Information (SEI) Processing Order (SPO) SEI message including syntax elements, wherein the syntax elements contain an identifier number to identify the SPO SEI message; generating a bitstream of the SPO SEI message including the syntax elements; and storing the bitstream in a non-transitory computer-readable recording medium.

[0038] The sixth aspect relates to the methods, apparatus, or systems described in this disclosure.

[0039] For clarity, any of the embodiments described above may be combined with any one or more other foregoing embodiments to create new embodiments within the scope of this disclosure.

[0040] These and other features will become clearer from the following detailed description by referring to the accompanying drawings and claims. Attached Figure Description

[0041] For a more complete understanding of this disclosure, reference is now made to the following brief description, which is taken in conjunction with the accompanying drawings and detailed description, wherein the same reference numerals denote the same parts.

[0042] Figure 1 is a block diagram illustrating an example video processing system.

[0043] Figure 2 is a block diagram of an example video processing device.

[0044] Figure 3 is a flowchart of an example method for video processing.

[0045] Figure 4 is a block diagram illustrating an example video codec system.

[0046] Figure 5 is a block diagram showing an example encoder.

[0047] Figure 6 is a block diagram showing an example decoder.

[0048] Figure 7 is a schematic diagram of an example encoder. Detailed Implementation

[0049] First, it should be understood that although illustrative implementations of one or more embodiments are provided below, the disclosed systems and / or methods can be implemented using any number of techniques, whether currently known or yet to be developed. This disclosure should not be limited in any way to the illustrative implementations, drawings, and techniques described below, including the exemplary designs and implementations described herein, but modifications can be made within the scope of the appended claims and all their equivalents.

[0050] Chapter headings are used in this disclosure for ease of understanding and not to limit the applicability of the techniques and embodiments disclosed in each chapter to that chapter only. Furthermore, H.266 terminology is used in some descriptions merely for ease of understanding and not to limit the scope of the disclosed techniques. Therefore, the techniques described herein are also applicable to other video codec protocols and designs. In this disclosure, edited changes to the text are shown in bold italics (indicating deleted text) and bold (indicating added text) relative to the Multi-Function Video Codec (VVC) specification and / or the Supplemental Enhancement Information (SEI) Message (VSEI) standard for encoding and decoding video bitstreams.

[0051] 1. Preliminary Discussion

[0052] This disclosure relates to image / video codec techniques. Specifically, this disclosure relates to signaling of post-processing filter banks (e.g., processing chains) that process sequential SEI messages using Supplemental Enhancement Information (SEI). This idea can be applied alone or in various combinations to video bitstreams encoded and decoded by any codec, such as the VVC standard and / or the Versatile SEI Message (VSEI) standard for encoding and decoding video bitstreams.

[0053] 2. Abbreviation

[0054] The following technologies are described: Adaptive Parameter Set (APS), Access Unit (AU), Codec Layer Video Sequence (CLVS), Codec Layer Video Sequence Start (CLVSS), Cyclic Redundancy Check (CRC), Codec Video Sequence (CVS), Finite Impulse Response (FIR), Intra-Frame Random Access Point (IRAP), Network Abstraction Layer (NAL), Picture Parameter Set (PPS), Picture Unit (PU), Random Access Skip Before (RASL) Picture, Supplemental Enhancement Information (SEI), Stepped Temporal Sublayer Access (STSA), Video Codec Layer (VCL), Multifunctional Supplemental Enhancement Information as described in Recommendation ITU-T H.274 | ISO / IEC 23002-7 (VSEI), and Video Availability Information (VUI) as described in Recommendation ITU-T H.266 | ISO / IEC 23090-3 (VVC).

[0055] 3. Further discussion

[0056] 3.1 Video Coding and Decoding Standards

[0057] Video coding standards have evolved primarily through the development of standards by the Telecommunication Standardization Sector of the International Telecommunication Union (ITU) (ITU-T) and the International Organization for Standardization (ISO) / International Electrotechnical Commission (IEC). ITU-T developed H.261 and H.263, while ISO / IEC developed Moving Picture Experts Group (MPEG)-1 and MPEG-4 Vision. The two organizations jointly developed the H.262 / MPEG-2 video standard, the H.264 / MPEG-4 Advanced Video Coding (AVC) standard, and the H.265 / High Efficiency Video Coding (HEVC) standard [1]. Starting with H.262, video coding standards are based on a hybrid video coding structure, which utilizes temporal prediction plus transform coding.

[0058] The Multi-Functional Video Coding (VVC) standard (ITU-T H.266 | ISO / IEC 23090-3) [2] and the related Multi-Functional Supplemental Enhancement Information (VSEI) standard (ITU-T H.274 | ISO / IEC 23002-7) [3] for codec video bitstreams are designed for the widest range of applications, including simple uses such as television broadcasting, video conferencing or playback from storage media, as well as more advanced use cases such as adaptive bitrate streaming, video region extraction, synthesis and merging of content from multiple codec video bitstreams, multi-view video, scalable layered coding and decoding and viewport-adaptive 360-degree (360°) immersive media.

[0059] 3.2 General SEI Messages and SEI Messages in VVC

[0060] SEI messages assist in processes related to decoding, display, or other purposes. However, SEI messages are not essential for constructing luma or chroma samples during the decoding process. Standard-compliant decoders do not need to process this information to achieve output order consistency. Some SEI messages are necessary for checking bitstream consistency and output timing decoder consistency. Other SEI messages are not necessary for checking bitstream consistency.

[0061] Appendix D of VVC specifies the syntax and semantics of SEI message payloads for some SEI messages, and specifies the use of SEI messages and VUI parameters with syntax and semantics specified in ITU-TH.SEI | ISO / IEC 23002-7.

[0062] 3.3 SEI Processing Order (SPO) SEI Messages

[0063] JVET-AE2027 [4] includes a specification for SEI messages called SEI Processing Order (SPO) SEI messages, which carry information indicating the preferred processing order of different types of SEI messages that may exist in a codec video sequence (CVS) that can be present in a bitstream, as determined by the encoder (content producer).

[0064] The specification for SPO SEI messages in JVET-AE2027 is as follows.

[0065] 3.3.1 General SEI Load Syntax

[0066]

[0067] 3.3.2 SEI Processing Order and SEI Message Syntax

[0068]

[0069] 3.3.3 SEI Processing Order and SEI Message Semantics

[0070] SEI Processing Order: SEI messages carry information indicating the preferred processing order for different types of SEI messages that may exist in CVS, as determined by the encoder (i.e., the content producer).

[0071] When an SEI processing order SEI message exists in any access unit of a CVS, it must also exist in the first access unit of the CVS. SEI processing order SEI messages continue from the current access unit in decoding order until the end of the CVS. When multiple SEI processing order SEI messages exist in a CVS, they must have the same content.

[0072] The requirement for bitstream consistency is that within the SEI processing order SEI message, there must be at least two pairs of syntax elements po_sei_payload_type[i] and po_sei_processing_order[i], and there must be at least two unequal po_sei_processing_order[i] values.

[0073] SEI processing order: SEI messages can carry one or more SEI prefix indicators for a specific payloadType. Each SEI prefix indicator is a byte string that follows the SEI payload syntax corresponding to the value of the payloadType, and the byte string contains a certain number of complete syntax elements starting from the first syntax element in the SEI payload, and may be followed by bits that do not represent any complete syntax elements of the SEI payload.

[0074] These SEI prefixes should provide sufficient information to determine the specific processing order of SEI messages with the same payloadType value but different preferred processing orders.

[0075] po_num_sei_messages_minus2 plus 2 indicates the number of SEI messages with the SEI processing order indicated in the SEI message.

[0076] po_sei_importance_flag[i] indicates the importance of the SEI message at index i, as determined by the encoder.

[0077] If the decoding system cannot interpret or does not support any SEI message with a po_sei_importance_flag[i] equal to 1, it should ignore the entire SEI processing order SEI message.

[0078] The `reserved_alignment_6bits` parameter is meaningless and must be equal to 0 in a bitstream conforming to this version of the specification. The decoder must allow this syntax element to have other values ​​and must ignore such values.

[0079] If po_sei_wrapping_flag[i] equals 0, then the SEI message should exist outside the SEI message processing order, where payloadType equals po_sei_payload_type[i]. However, if po_sei_wrapping_flag[i] equals 0 and there is no SEI message with payloadType equal to po_sei_payload_type[i], then the following applies:

[0080] - If po_sei_importance_flag[i] equals 1, the decoder should ignore the entire SEI processing order SEI message;

[0081] Otherwise, the decoder should ignore all data associated with the loop variable value i.

[0082] Note that `po_sei_wrapping_flag[i]` equal to 1 enables the carrying of SEI messages within SEI messages processed in the SEI processing order, preventing such SEI messages from being misinterpreted by decoders that do not process SEI messages in the SEI processing order. Therefore, `po_sei_wrapping_flag[i]` equal to 1 is intended to be used when `po_sei_wrapping_flag[i]` equal to 0 would lead to undesirable results from such decoders.

[0083] A value of 1 for po_sei_prefix_flag[i] indicates that po_num_prefix_bytes[i] exists. A value of 0 for po_sei_prefix_flag[i] indicates that po_num_prefix_bytes[i] does not exist.

[0084] `po_sei_payload_type[i]` specifies the `payloadType` value for the `i`-th SEI message type, providing preferred processing order information in the SEI message for that `i`-th SEI message type. For any two distinct non-negative integer values ​​`m` and `n`, the values ​​of `po_sei_payload_type[m]` and `po_sei_payload_type[n]` should not be the same unless both `po_sei_prefix_flag[m]` and `po_sei_prefix_flag[n]` are equal to 1.

[0085] SeiProcessingOrderSeiList is set to consist of payloadType values ​​as specified in entry D.2.1, except for the values ​​137, 144, 147, 148, 179, 180, 200, 201, 208, and 213. When po_sei_payload_type[i] is not equal to any value in SeiProcessingOrderSeiList, the value of po_sei_prefix_flag[i] must be equal to 0.

[0086] po_num_prefix_bytes[i] (if present) specifies the number of bytes associated with the i-th SEI message, which provides preferred processing order information for that i-th SEI message in the SEI processing order. If it does not exist, the value of po_num_prefix_bytes[i] is presumed to be 0.

[0087] po_prefix_byte[i][j] (if present) specifies the value of the j-th byte of the i-th SEI message.

[0088] po_sei_processing_order[i] indicates the preferred processing order for the i-th SEI message type, and the preferred processing order information is provided in the SEI processing order SEI message for the i-th SEI message type. For any two distinct integer values ​​m and n greater than or equal to 0, po_sei_processing_order[m] less than po_sei_processing_order[n] indicates that any SEI message type with payloadType equal to po_sei_payload_type[m] and bytes po_prefix_byte[m][p] (if present) ranging from 0 to po_num_prefix_bytes[m] - 1 (inclusive) must be processed before any SEI message type with payloadType equal to po_sei_payload_type[n] and bytes po_prefix_byte[n][q] (inclusive) ranging from 0 to po_num_prefix_bytes[n] - 1 (inclusive) (if present), and po_sei_processing_order[m] equal to po_sei_processing_order[n] indicates that there is no preferred processing order among SEI message types. When there are multiple SEI messages with the same values ​​of po_sei_payload_type[i], po_num_prefix_bytes[i], and j ranging from 0 to po_num_prefix_bytes[i] - 1 (inclusive), they must have the same value of po_sei_processing_order[i].

[0089] po_sei_processing_order[0] must be equal to 0, and for i greater than 0, po_sei_processing_order[i] must be equal to po_sei_processing_order[i-1] or po_sei_processing_order[i-1]+1.

[0090] The value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] should not be equal to 0.

[0091] 3.4 Signaling of Neural Network Post-processing Filters

[0092] JVET-AE2006 [5] includes specifications for two SEI messages used for signaling of neural network post-processing filters: the Neural Network Post-Processing Filter Feature (NNPFC) SEI message and the Neural Network Post-Processing Filter Activation (NNPFA) SEI message. JVET-AE2005 [6] includes specifications for the use of NNPFC SEI messages in VVC bitstreams.

[0093] The specifications for NNPFC and NNPFA SEI messages in JVET-AE2006, as well as the usage specifications for NNPFC SEI messages in VVC bitstreams, are as follows.

[0094] 4. The technical problem solved by the disclosed technical solution

[0095] The example design for processing sequential SEI messages has the following problems.

[0096] First, although the SEI message type transmitted via signaling in the SEI processing order (SPO) SEI message can essentially be considered as a cascaded group of post-processing filters (PPFs), there is a lack of a mechanism for using SPO SEI messages to transmit different PPF groups (including but not limited to NNPFs) via signaling, where for any given image only one group can be selected to be applied, while any group with (multiple) active PPFs can be selected.

[0097] Second, when different PPF groups are transmitted via signaling through different SPO SEI messages, allowing them to have the same PPF (especially the same NNPF or PPF indicated by the color transformation information SEI message) would be problematic regarding which PPF group a particular PPF belongs to.

[0098] Third, within a cascaded PPF group, if any PPF except the last one interpolates the image during application, the input image for subsequent PPFs will be difficult.

[0099] Fourth, within a cascaded PPF group, when only the last PPF can be used to interpolate the image during application, explicitly transmitting the order of the last PPF via signaling is a waste of bits.

[0100] Fifth, when it exists, it is meaningless for po_num_prefix_bytes[i] to be equal to 0.

[0101] 5. List of solutions and implementation examples

[0102] To address the aforementioned problems, methods outlined below are disclosed. These aspects should be considered as examples for interpreting general concepts, and not interpreted in a narrow sense. Furthermore, these examples can be applied individually or in any combination.

[0103] 1) To solve the first problem, one or more of the following methods are specified:

[0104] a. In one example, an identifier (e.g., as a syntax element named po_id) is transmitted via signaling in the SEI processing order SEI message to identify a group of SEI message types for which the preferred processing order is indicated in the SEI processing order SEI message.

[0105] b. In one example, it is specified that the post-processing filter (PPF) can be indicated by the SEI message with the payloadType value in SeiProcessingOrderSeiList.

[0106] c. In one example, it is specified that for each image, there can be multiple active PPFs belonging to one or more PPF groups. PPF groups are interchangeable, meaning that at most one group can be selected to be applied.

[0107] d. In one example, a special PPF cascading case is defined as the situation where two PPFs are activated for the same image: both PPFs are NNPFs (i.e., the payloadType value of the NNPF indicates the neural network post-processing filter feature SEI message), one of the NNPFs has nnpfc_purpose equal to 4 and the other has multiple input images, and neither NNPF is associated with the SEI message processing order. In this case, the two NNPFs are implicitly considered to belong to a PPF group, and the NNPF with nnpfc_purpose equal to 4 is applied first.

[0108] i. Alternatively, other special PPF cascade cases can be defined.

[0109] ii. In one example, how these special cases are handled (e.g., whether they are in a PPF group, the order in which PPFs are processed) is fixed and not indicated in the bitstream or transmitted via signals.

[0110] 1. Alternatively, how to handle these special cases can still be indicated / transmitted via signals in the bitstream, but the indicated / transmitted information is ignored, and predefined processing methods are applied.

[0111] 2. Alternatively, the order in which PPF is applied in these special cases is predefined, and the bitstream consistency requirement is that the indicated order must be the same as the predefined order.

[0112] e. In one example, it is specified that, except in special PPF cascading cases, each PPF group containing multiple PPFs is associated with an SEI processing order SEI message having a specific value of a syntax element (e.g., named po_id).

[0113] i. Alternatively, in all cases, each PPF group containing multiple PPFs is associated with an SEI message of SEI processing order having a specific value for a syntax element (e.g., po_id).

[0114] f. In one example, it is specified that, except in special PPF cascading cases, any PPF not associated with the SEI processing order SEI message is in its own PPF group.

[0115] i. Alternatively, in all cases, any PPF not associated with the SEI message processing order is in its own PPF group.

[0116] g. In one example, it is specified that one or more PPFs from the selected PPF group can be applied. When multiple PPFs are applied (within the selected PPF group), they are applied in a cascading manner, which means that they are applied in the order indicated by the SEI processing order message associated with the selected PPF group, and for each PPF that is not the last PPF applied, the output is used as the input of the next PPF applied.

[0117] i. Alternatively, it may be specified that one or more PPFs from the selected PPF group may be applied. When multiple PPFs are applied (within the selected PPF group), they are applied in a cascading manner, meaning that they are applied in the order indicated by the SEI processing order SEI message associated with the selected PPF group, and for each PPF that is not the last PPF applied, (multiple) output pictures are used as (multiple) input pictures for the next PPF applied.

[0118] 2) To solve the second problem, one or more of the following methods are specified:

[0119] a. In one example, the constraint is that color transformation information SEI messages associated with different SEI processing orders must have different colour_transform_id values.

[0120] i. In one example, the constraints are specified as follows: For any two SEI processing orders present in CVS, SEI messages spoSeiA and spoSeiB, when spoSeiA contains an entry where po_sei_payload_type[i] equals 142 (i.e., the payloadType of the color transformation information SEI message) and spoSeiB contains an entry where po_sei_payload_type[j] equals 142, i and j can be the same or different, po_sei_prefix_flag[i] in spoSeiA and po_sei_prefix_flag[j] in spoSeiB must both be equal to 1, and the value of the colour_transform_id syntax element contained in the SEI prefix indication of the i-th entry in spoSeiA should not be equal to the value of the colour_transform_id syntax element contained in the SEI prefix indication of the j-th entry in spoSeiB. The same applies when po_sei_wrapping_flag[i] in sposeiA or po_sei_wrapping_flag[j] in sposeiB is equal to 1. In this case, the colour_transform_id syntax element is directly included in the encapsulated SEI message.

[0121] b. In one example, the neural network post-processing filter characteristics associated with SEI messages for different SEI processing orders must have different nnpfc_id values.

[0122] i. In one example, the constraints are specified as follows: For any two SEI processing orders SEI messages spoSeiA and spoSeiB existing in CVS, when spoSeiA contains an entry where po_sei_payload_type[i] equals 210 (i.e., the payloadType of the SEI message for the neural network post-processing filter feature) and spoSeiB contains an entry where po_sei_payload_type[j] equals 210, i and j can be the same or different, po_sei_prefix_flag[i] in spoSeiA and po_sei_prefix_flag[j] in spoSeiB must both be equal to 1, and the value of the nnpfc_id syntax element contained in the SEI prefix indication of the i-th entry in spoSeiA should not be equal to the value of the nnpfc_id syntax element contained in the SEI prefix indication of the j-th entry in spoSeiB. The same applies when po_sei_wrapping_flag[i] in sposeiA or po_sei_wrapping_flag[j] in sposeiB is equal to 1. In this case, the nnpfc_id syntax element is directly included in the encapsulated SEI message.

[0123] c. In one example, the NNPFA SEI message is extended to enable NNPF activation for a specific PPF group.

[0124] i. In one example, in an NNPFA SEI extension, the po_id can also be signaled to activate the NNPF of a specific PPF group with the po_id.

[0125] d. In one example, a new activation SEI message is specified for non-NN PPF.

[0126] i. In one example, in a new activation SEI message, the id of a non-NN PPF can be transmitted at least by signaling.

[0127] e. In one example, the non-PPF SEI message itself is extended to enable the activation of a PPF for a specific PPF group.

[0128] 3) To solve the third problem, one or more of the following methods are specified:

[0129] a. In one example, within the SEI processing order SEI message, at most one SEI message type can indicate a post-processing filter that will interpolate the image at application time.

[0130] b. In one example, within the SEI processing order of SEI messages, only the last SEI message type can indicate the post-processing filter that will interpolate the image at the time of application.

[0131] 4) To address the fourth problem, in one example, the preferred processing order for PPFs that will interpolate the image during application is not explicitly transmitted via signaling, but is presumed to be the penultimate PPF's indication order plus one.

[0132] a. In one example, a flag (e.g., named po_last_ppf_picture_interpolation_flag) is added outside the loop "for( i = 0, i < po_num_sei_messages_minus2 + 2; i++)", and po_sei_processing_order[ i ] is conditional on "if( ( i < po_num_sei_messages_minus2 + 1 ) || !po_last_ppf_picture_interpolation_flag )", and the value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to po_sei_processing_order[ po_num_sei_messages_minus2 ] + 1.

[0133] b. In one example, the flag po_last_ppf_picture_interpolation_flag is not transmitted via signaling, but variables (e.g., named PoLastPpfPictureInterpolationFlag) are inferred based on the SEI payloadType and the SEI prefix indication of the last entry (if present), which indicates whether the last PPF will interpolate the image when applied, and po_sei_processing_order[i] is conditional on "if( (i < po_num_sei_messages_minus2 + 1) || ! PoLastPpfPictureInterpolationFlag)", and the value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1] is presumed to be equal to po_sei_processing_order[ po_num_sei_messages_minus2] + 1.

[0134] 5) To address the fifth problem, the syntax element po_num_prefix_bytes[i] is changed to po_num_prefix_bytes_minus1[i], which means that the number of prefix bytes transmitted by signal is reduced by 1 instead of the number of prefix bytes transmitted by signal.

[0135] a. Alternatively, the syntax element po_num_prefix_bytes[i] remains unchanged, po_sei_prefix_flag is removed, and whether the prefix is ​​available depends on whether po_num_prefix_bytes[i] is zero.

[0136] 6. Examples

[0137] The following are some example implementations of the aspects outlined in Section 5 of the previous article.

[0138] 6.1 Example 1

[0139] Most of the relevant sections that have been added or modified are shown in bold, and some of the deleted sections are shown in italics. There may be some other changes that are editable in nature and therefore not indicated.

[0140] This embodiment refers to the following items outlined in Section 5 of the previous article: all sub-items of item 1, item 5.

[0141] D.11 SEI Processing Order SEI Messages

[0142] D.11.1 SEI Processing Order SEI Message Syntax

[0143]

[0144] D.11.2 SEI Processing Order and SEI Message Semantics

[0145]

[0146]

[0147]

[0148] The requirement for bitstream consistency is that within the SEI processing order SEI message, there must be at least two pairs of syntax elements po_sei_payload_type[i] and po_sei_processing_order[i], and there must be at least two unequal po_sei_processing_order[i] values.

[0149] SEI processing order: SEI messages can carry one or more SEI prefix indicators for a specific payloadType. Each SEI prefix indicator is a byte string that follows the SEI payload syntax corresponding to the value of the payloadType, and the byte string contains a certain number of complete syntax elements starting from the first syntax element in the SEI payload, and may be followed by bits that do not represent any complete syntax elements of the SEI payload.

[0150] These SEI prefixes indicate that sufficient information must be provided to determine the specific processing order of SEI messages with the same payloadType value but different preferred processing orders.

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157] po_num_sei_messages_minus2 plus 2 indicates the number of SEI messages with the SEI processing order indicated in the SEI message.

[0158] po_sei_importance_flag[i] indicates the importance of the SEI message at index i, as determined by the encoder.

[0159] If the decoding system cannot interpret or does not support any SEI message indicating that po_sei_importance_flag[i] is equal to 1, then it should ignore the entire SEI processing order SEI message.

[0160]

[0161]

[0162] If po_sei_wrapping_flag[i] equals 0, then the SEI message should exist outside the SEI message processing order, where payloadType equals po_sei_payload_type[i]. However, if po_sei_wrapping_flag[i] equals 0 and there is no SEI message with payloadType equal to po_sei_payload_type[i], then the following applies:

[0163] - If po_sei_importance_flag[i] equals 1, the decoder should ignore the entire SEI processing order SEI message.

[0164] Otherwise, the decoder should ignore all data associated with the loop variable value i.

[0165] Note 2 - `po_sei_wrapping_flag[i]` equal to 1 enables the carrying of SEI messages within SEI messages processed in the SEI processing order, preventing such SEI messages from being misinterpreted by decoders that do not process SEI messages in the SEI processing order. Therefore, `po_sei_wrapping_flag[i]` equal to 1 is intended to be used when `po_sei_wrapping_flag[i]` equal to 0 would lead to undesirable results from such decoders.

[0166] A value of 1 for po_sei_prefix_flag[i] indicates the existence of po_num_prefix_bytes[i]. A value of 0 for po_sei_prefix_flag[i] indicates the non-existence of po_num_prefix_bytes[i].

[0167] `po_sei_payload_type[i]` specifies the `payloadType` value for the `i`-th SEI message type, providing preferred processing order information in the SEI message for that `i`-th SEI message type. For any two distinct non-negative integer values ​​`m` and `n`, the values ​​of `po_sei_payload_type[m]` and `po_sei_payload_type[n]` should not be the same unless both `po_sei_prefix_flag[m]` and `po_sei_prefix_flag[n]` are equal to 1.

[0168] SeiProcessingOrderSeiList is set to consist of payloadType values ​​as specified in entry D.2.1, except for the values ​​137, 144, 147, 148, 179, 180, 200, 201, 208, and 213. When po_sei_payload_type[i] is not equal to any value in SeiProcessingOrderSeiList, the value of po_sei_prefix_flag[i] must be equal to 0.

[0169]

[0170]

[0171] po_prefix_byte[i][j] (if present) specifies the value of the j-th byte of the i-th SEI message.

[0172] po_sei_processing_order[i] indicates the preferred processing order for the i-th SEI message type, and the preferred processing order information is provided in the SEI processing order SEI message for the i-th SEI message type. For any two distinct integer values ​​m and n greater than or equal to 0, po_sei_processing_order[m] less than po_sei_processing_order[n] indicates that any SEI message type with payloadType equal to po_sei_payload_type[m] and bytes po_prefix_byte[m][p] (if present) ranging from 0 to po_num_prefix_bytes[m] - 1 (inclusive) must be processed before any SEI message type with payloadType equal to po_sei_payload_type[n] and bytes po_prefix_byte[n][q] (if present) ranging from 0 to po_num_prefix_bytes[n] - 1 (inclusive) and po_sei_processing_order[m] equal to po_sei_processing_order[n] indicates that there is no preferred processing order among SEI message types. When there are multiple SEI messages with the same values ​​of po_sei_payload_type[i], po_num_prefix_bytes[i], and j ranging from 0 to po_num_prefix_bytes[i] - 1 (inclusive), they must have the same value of po_sei_processing_order[i].

[0173] po_sei_processing_order[0] must be equal to 0, and for i greater than 0, po_sei_processing_order[i] must be equal to po_sei_processing_order[i-1] or po_sei_processing_order[i-1]+1.

[0174] The value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] should not be equal to 0.

[0175] 6.2 Example 2

[0176] This embodiment refers to items 1 to 4 as outlined in Section 5 of the previous article. Changes relative to Embodiment 1 are marked. Based on Embodiment 1, this embodiment refers to the following items as outlined in Section 5 of the previous article: 3.b, 4, 4.a.

[0177] D.11 SEI Processing Order SEI Messages

[0178] D.11.1 SEI Processing Order SEI Message Syntax

[0179]

[0180] D.11.2 SEI Processing Order and SEI Message Semantics

[0181] SEI Processing Order: SEI messages carry information indicating the preferred processing order for a set of different types of SEI messages that may exist in CVS, as determined by the encoder (i.e., the content producer), and these different types of SEI messages may be applied in a cascading manner.

[0182] Note 1 - In the semantics of this SEI message, two different types of SEI messages can have the same SEIpayloadType value, but are distinguished by some syntax elements in the SEI payload. For example, two Neural Network Post-Filter Feature (NNPFC) SEI messages with different nnpfc_id values ​​are considered to be two different types of SEI messages.

[0183] When a Sequential SEI message with a specific po_id value exists in any access unit of a CVS, it must also exist in the first access unit of the CVS. Sequential SEI messages continue from the current access unit in decoding order until the end of the CVS. When multiple Sequential SEI messages with the same po_id value exist in a CVS, they must have identical content.

[0184]

[0185]

[0186] The requirement for bitstream consistency is that within the SEI processing order SEI message, there must be at least two pairs of syntax elements po_sei_payload_type[i] and po_sei_processing_order[i], and there must be at least two unequal po_sei_processing_order[i] values.

[0187] SEI processing order: SEI messages can carry one or more SEI prefix indicators for a specific payloadType. Each SEI prefix indicator is a byte string that follows the SEI payload syntax corresponding to the value of that payloadType, and the byte string contains a certain number of complete syntax elements starting from the first syntax element in the SEI payload, and may be followed by bits that do not represent any complete syntax elements of the SEI payload.

[0188] These SEI prefixes indicate that sufficient information must be provided to determine the specific processing order of SEI messages with the same payloadType value but different preferred processing orders.

[0189] `po_id` contains an identifier that identifies a group of SEI message types, indicating the preferred processing order for that group of SEI message types in the SEI processing order message. The value of `po_id` must be between 0 and 2. 32 - Within the range of 2 (inclusive). The value of po_id is from 256 to 511 (inclusive) and from 2... 31 to 2 32 - 2 (inclusive of end value) is reserved for future use by ITU-T | ISO / IEC. Decoders conforming to this version of the document encounter po_id in the range of 256 to 511 (inclusive of end value) or in 2. 31 to 2 32 When processing SEI messages within the range of -2 (inclusive), the SEI message must be ignored.

[0190] The post-processing filter (PPF) can be indicated by the payloadType value in the SEI message specified in SeiProcessingOrderSeiList as follows.

[0191] For each image, there can be multiple active PPFs belonging to one or more PPF groups. PPF groups are interchangeable, meaning that at most one group can be selected to be applied.

[0192] A special case of PPF cascading is defined as when two PPFs are activated for the same image: both PPFs are NNPFs (i.e., the payloadType value of the NNPF indicates the SEI message of the neural network post-processing filter), one of the NNPFs has an nnpfc_purpose equal to 4 and the other has multiple input images, and neither NNPF is associated with the SEI message processing order. In this case, the two NNPFs are implicitly considered to belong to a PPF group, and the NNPF with nnpfc_purpose equal to 4 is applied first.

[0193] Except in special PPF cascading cases, each PPF group containing multiple PPFs is associated with an SEI message in the SEI processing order with a specific po_id value. Except in special PPF cascading cases, any PPF not associated with an SEI message in the SEI processing order resides in its own PPF group.

[0194] One or more PPFs from the selected PPF group can be applied. When multiple PPFs are applied (within the selected PPF group), they are applied in a cascading manner, which means that they are applied in the order indicated by the SEI processing order message associated with the selected PPF group, and for each PPF that is not the last PPF applied, the output is used as the input of the next PPF applied.

[0195] po_num_sei_messages_minus2 plus 2 indicates the number of SEI messages with the SEI processing order indicated in the SEI message.

[0196] po_num_sei_messages_minus2 plus 2 indicates the number of SEI messages with the SEI processing order indicated in the SEI message.

[0197]

[0198] If the decoding system cannot interpret or does not support any SEI message indicating that po_sei_importance_flag[i] is equal to 1, then it must ignore the entire SEI processing order SEI message.

[0199] po_alignment_zero_bit must be equal to 0.

[0200] If po_sei_wrapping_flag[i] equals 0, then the SEI message should exist outside the SEI message processing order, where payloadType equals po_sei_payload_type[i]. However, if po_sei_wrapping_flag[i] equals 0 and there is no SEI message with payloadType equal to po_sei_payload_type[i], then the following applies:

[0201] - If po_sei_importance_flag[i] equals 1, the decoder should ignore the entire SEI processing order SEI message.

[0202] Otherwise, the decoder should ignore all data associated with the loop variable value i.

[0203] Note 2 - `po_sei_wrapping_flag[i]` equal to 1 enables the carrying of SEI messages within SEI messages processed in the SEI processing order, preventing such SEI messages from being misinterpreted by decoders that do not process SEI messages in the SEI processing order. Therefore, `po_sei_wrapping_flag[i]` equal to 1 is intended to be used when `po_sei_wrapping_flag[i]` equal to 0 would lead to undesirable results from such decoders.

[0204] A value of 1 for po_sei_prefix_flag[i] indicates the existence of po_num_prefix_bytes[i]. A value of 0 for po_sei_prefix_flag[i] indicates the non-existence of po_num_prefix_bytes[i].

[0205] `po_sei_payload_type[i]` specifies the `payloadType` value for the `i`-th SEI message type, providing preferred processing order information in the SEI message for that `i`-th SEI message type. For any two distinct non-negative integer values ​​`m` and `n`, the values ​​of `po_sei_payload_type[m]` and `po_sei_payload_type[n]` should not be the same unless both `po_sei_prefix_flag[m]` and `po_sei_prefix_flag[n]` are equal to 1.

[0206] SeiProcessingOrderSeiList is set to consist of payloadType values ​​as specified in entry D.2.1, except for the values ​​137, 144, 147, 148, 179, 180, 200, 201, 208, and 213. When po_sei_payload_type[i] is not equal to any value in SeiProcessingOrderSeiList, the value of po_sei_prefix_flag[i] must be equal to 0.

[0207] When present, po_num_prefix_bytes_minus1[i] increments by 1 to specify the number of bytes associated with the i-th SEI message, which provides preferred processing order information for the i-th SEI message in the SEI processing order.

[0208] po_prefix_byte[i][j] (if present) specifies the value of the j-th byte of the i-th SEI message.

[0209] po_sei_processing_order[i] indicates the preferred processing order for the i-th SEI message type, and the preferred processing order information is provided in the SEI processing order SEI message for the i-th SEI message type. For any two distinct integer values ​​m and n greater than or equal to 0, po_sei_processing_order[m] less than po_sei_processing_order[n] indicates that any SEI message type with payloadType equal to po_sei_payload_type[m] and bytes po_prefix_byte[m][p] (if present) ranging from 0 to po_num_prefix_bytes[m] - 1 (inclusive) must be processed before any SEI message type with payloadType equal to po_sei_payload_type[n] and bytes po_prefix_byte[n][q] (if present) ranging from 0 to po_num_prefix_bytes[n] - 1 (inclusive) and po_sei_processing_order[m] equal to po_sei_processing_order[n] indicates that there is no preferred processing order among SEI message types. When there are multiple SEI messages with the same values ​​of po_sei_payload_type[i], po_num_prefix_bytes[i], and j ranging from 0 to po_num_prefix_bytes[i] - 1 (inclusive), they must have the same value of po_sei_processing_order[i].

[0210]

[0211] po_sei_processing_order[0] must be equal to 0, and for i greater than 0, po_sei_processing_order[i] must be equal to po_sei_processing_order[i-1] or po_sei_processing_order[i-1]+1.

[0212] The value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] shall not be equal to 0.

[0213] 7. References

[0214] [1] ITU-T and ISO / IEC, “High efficiency video coding”, Rec. ITU-T H.265 | ISO / IEC 23008-2 (in force edition).

[0215] [2] ITU-T and ISO / IEC, “Versatile Video Coding”, Rec. ITU-T H.266 | ISO / IEC 23090-3.

[0216] [3] ITU-T and ISO / IEC, “Versatile Supplemental Enhancement Information Messages for Coded Video Bitstreams”, Rec. ITU-T Rec. H.274 | ISO / IEC 23002-7.

[0217] [4] S. McCarthy, M. M. Hannuksela, and Y.-K. Wang (eds), JVET-AE2027, “SEI processing order SEI message in VVC (draft 5)”.

[0218] [5] S. McCarthy, T. Chujoh, M. Hannuksela, G. J. Sullivan, and Y.-K. Wang (editors), “Additional SEI messages for VSEI (Draft 5)”, JVET output document JVET-AE2006, publicly available online herein: https: / / jvet-experts.org / doc_end_user / current_document.php?id=13271.

[0219] [6] B. Bross, E. François, MM Hannuksela, A. Tourapis, and Y.-K.Wang (editors), “New level and systems-related supplemental enhancement information for VVC (Draft 6)”, JVET output document JVET-AE2005, publicly available online herein: https: / / jvet-experts.org / doc_end_user / current_document.php?id=13270.

[0220] Figure 1 is a block diagram illustrating an example video processing system 4000 in which various techniques disclosed herein may be implemented. Various implementations may include some or all of the components of system 4000. System 4000 may include an input 4002 for receiving video content. The video content may be received in a raw or uncompressed format, such as 8 or 10-bit multi-component pixel values, or it may be received in a compressed or encoded format. Input 4002 may represent a network interface, a peripheral bus interface, or a storage interface. Examples of network interfaces include wired interfaces (such as Ethernet, Passive Optical Networking (PON), etc.) and wireless interfaces (such as Wi-Fi or cellular interfaces).

[0221] System 4000 may include an encoding component 4004 capable of implementing the various encoding / decoding or encoding methods described in this disclosure. Encoding component 4004 may reduce the average bit rate from the video input 4002 to the output of encoding component 4004 to produce an encoded representation of the video. Encoding techniques are therefore sometimes referred to as video compression or video transcoding techniques. The output of encoding component 4004 may be stored or transmitted via a communication connection such as that represented by component 4006. The bitstream (or encoded) representation of the video received at input 4002, whether stored or communicated, may be used by component 4008 to generate pixel values ​​or displayable video to be transmitted to display interface 4010. The process of generating user-visible video from the bitstream representation is sometimes referred to as video decompression. Furthermore, although some video processing operations are referred to as “encoding” operations or tools, it should be understood that encoding tools or operations used at the encoder will be followed by corresponding decoding tools or operations that inversely decode the encoded result, performed by the decoder.

[0222] Examples of peripheral bus interfaces or display interfaces may include Universal Serial Bus (USB), High Definition Multimedia Interface (HDMI), or DisplayPort. Examples of storage interfaces include Serial Advanced Technology Attachment (SATA), Peripheral Component Interconnect (PCI), Integrated Drive Electronic Devices (IDE), etc. The technologies described in this disclosure can be embodied in a variety of electronic devices, such as mobile phones, laptops, smartphones, or other devices capable of performing digital data processing and / or video display.

[0223] Figure 2 is a block diagram of an example video processing apparatus 4100. Apparatus 4100 can be used to implement one or more methods described herein. Apparatus 4100 can be embodied in a smartphone, tablet, computer, Internet of Things (IoT) receiver, etc. Apparatus 4100 may include one or more processors 4102, one or more memories 4104, and video processing circuitry 4106. The processors 4102(s) may be configured to implement one or more methods described herein. The memories 4104(s) may be used to store data and code for implementing the methods and techniques described herein. The video processing circuitry 4106 may be used to implement some of the techniques described herein in hardware circuitry. In some embodiments, the video processing circuitry 4106 may be at least partially included in the processor 4102, for example, a graphics coprocessor.

[0224] Figure 3 is a flowchart of an example method 4200 for video processing. Method 4200 includes step 4202: determining a Supplemental Enhancement Information (SEI) Processing Order (SPO). The SEI message includes a syntax element containing an identifier to identify the SPO message. In one embodiment, the SPO SEI message carries information indicating a preferred processing order for a set of SEI message types in a video sequence being encoded and decoded. In one embodiment, the syntax element is specified as po_id. In step 4204, a conversion between visual media data and a bitstream is performed based on the syntax element. The conversion may include encoding at the encoder, decoding at the decoder, or a combination thereof.

[0225] It should be noted that method 4200 can be implemented in an apparatus for processing video data, including a processor and a non-transitory memory having instructions thereon, such as a video encoder 4400, a video decoder 4500, and / or an encoder 4600. In this case, the instructions cause the processor to execute method 4200 when executed by the processor. Furthermore, method 4200 can be executed by a non-transitory computer-readable medium including a computer program product for use by a video codec device. The computer program product includes computer-executable instructions stored on the non-transitory computer-readable medium, causing the video codec device to execute method 4200 when executed by a processor.

[0226] Figure 4 is a block diagram illustrating an example video encoding / decoding system 4300 that can utilize the techniques of this disclosure. The video encoding / decoding system 4300 may include a source device 4310 and a target device 4320. The source device 4310 generates encoded video data, and this source device 4310 may be referred to as a video encoding device. The target device 4320 can decode the encoded video data generated by the source device 4310, and this target device 4320 may be referred to as a video decoding device.

[0227] Source device 4310 may include video source 4312, video encoder 4314, and input / output (I / O) interface 4316. Video source 4312 may include sources such as video capture devices, interfaces for receiving video data from video content providers, and / or computer graphics systems for generating video data, or combinations thereof. Video data may include 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 forming a codec representation of the video data. The bitstream may include codec pictures and associated data. Codec pictures are codec representations of pictures. 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. Encoded video data may be transmitted directly to target device 4320 via network 4330 through I / O interface 4316. Encoded video data may also be stored on storage medium / server 4340 for access by target device 4320.

[0228] Target device 4320 may include I / O interface 4326, video decoder 4324, and 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 source device 4310 or 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 may be integrated with target device 4320 or may be external to target device 4320, wherein target device 4320 may be configured to interface with an external display device.

[0229] The video encoder 4314 and the video decoder 4324 can operate according to video compression standards, such as the High Efficiency Video Coding (HEVC) standard, the Multi-Functional Video Coding (VVC) standard, and other existing and / or further standards.

[0230] Figure 5 is a block diagram illustrating an example of a video encoder 4400, which may be the video encoder 4314 in the system 4300 shown in Figure 4. The video encoder 4400 may be configured to perform any or all of the techniques disclosed herein. The video encoder 4400 includes multiple functional components. The techniques described in this disclosure may be shared among the various components of the video encoder 4400. In some examples, a processor may be configured to perform any or all of the techniques described in this disclosure.

[0231] The functional components of the video encoder 4400 may include a segmentation unit 4401, a prediction unit 4402 (which may include a mode selection unit 4403, a motion estimation unit 4404, a motion compensation unit 4405, and an intra-frame 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 coding unit 4414.

[0232] In other examples, the video encoder 4400 may include more, fewer, or different functional components. In one example, the prediction unit 4402 may include an intra-block copy (IBC) unit. The IBC unit can perform prediction in IBC mode, where at least one reference picture is the picture containing the current video block.

[0233] Furthermore, some components such as the motion estimation unit 4404 and the motion compensation unit 4405 can be highly integrated, but for illustrative purposes, these components are represented separately in the example of the video encoder 4400.

[0234] The segmentation unit 4401 can segment an image into one or more video blocks. The video encoder 4400 and the video decoder 4500 can support various video block sizes.

[0235] The mode selection unit 4403 can select one of several encoding / decoding modes (intra-frame encoding / decoding or inter-frame encoding / decoding), for example, based on error results, and provide the resulting intra-frame or inter-frame encoded / decoded block to the residual generation unit 4407 to generate residual block data, and to the reconstruction unit 4412 to reconstruct the coded block for use as a reference image. In some examples, the mode selection unit 4403 can select an intra-frame / inter-frame joint prediction (CIIP) mode, where prediction is based on inter-frame prediction signals and intra-frame prediction signals. In the case of inter-frame prediction, the mode selection unit 4403 can also select a resolution for the block based on motion vectors (e.g., sub-pixel precision or integer pixel precision).

[0236] To perform inter-frame prediction on the current video block, motion estimation unit 4404 can generate motion information for the current video block by comparing one or more reference frames from buffer 4413 with the current video block. Motion compensation unit 4405 can determine the predicted video block for the current video block based on the motion information and decoded samples of images from buffer 4413 other than the image associated with the current video block.

[0237] The motion estimation unit 4404 and the motion compensation unit 4405 can perform different operations on the current video block, for example, depending on whether the current video block is in an I-band, P-band, or B-band.

[0238] In some examples, motion estimation unit 4404 can perform unidirectional prediction on the current video block, and can search for a reference video block for the current video block in the reference images of list 0 or list 1. Motion estimation unit 4404 can then generate a reference index indicating the reference image containing the reference video block in list 0 or list 1, and a motion vector indicating the spatial displacement between the current video block and the reference video block. Motion estimation unit 4404 can output the reference index, prediction direction indicator, and motion vector as motion information for the current video block. Motion compensation unit 4405 can generate a predicted video block for the current block based on the reference video block indicated by the motion information of the current video block.

[0239] In other examples, motion estimation unit 4404 can perform bidirectional prediction on the current video block. Motion estimation unit 4404 can search for a reference video block for the current video block in the reference images in list 0, and can also search for another reference video block for the current video block in the reference images in list 1. Motion estimation unit 4404 can then generate reference indices indicating the reference images containing the reference video blocks in lists 0 and 1, and motion vectors indicating the spatial displacement between the reference video blocks and the current video block. Motion estimation unit 4404 can output the reference index and motion vector of the current video block as motion information for the current video block. Motion compensation unit 4405 can generate a predicted video block for the current video block based on the reference video blocks indicated by the motion information of the current video block.

[0240] In some examples, the motion estimation unit 4404 can output a complete set of motion information for use in the decoder's decoding process. In some examples, the motion estimation unit 4404 may not output a complete set of motion information for the current video. Instead, the motion estimation unit 4404 can reference the motion information of another video block to transmit the motion information of the current video block via a signal. For example, the motion estimation unit 4404 may determine that the motion information of the current video block is sufficiently similar to the motion information of neighboring video blocks.

[0241] In one example, the motion estimation unit 4404 may indicate a value to the video decoder 4500 in the syntax structure associated with the current video block, which indicates that the current video block has the same motion information as another video block.

[0242] In another example, motion estimation unit 4404 may identify another video block and motion vector difference (MVD) in the syntax structure associated with the current video block. The motion vector difference indicates the difference between the motion vector of the current video block and the motion vector of the indicated video block. 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.

[0243] As discussed above, the video encoder 4400 can transmit motion vectors via signaling in a predictive manner. Two examples of predictive signaling techniques that can be implemented by the video encoder 4400 include Advanced Motion Vector Prediction (AMVP) and Merge Pattern Signaling.

[0244] Intra-prediction unit 4406 can perform intra-prediction on the current video block. When intra-prediction unit 4406 performs intra-prediction on the current video block, it can generate prediction data for the current video block based on decoded samples of other video blocks in the same frame. The prediction data for the current video block can include the predicted video block and various syntax elements.

[0245] The residual generation unit 4407 can generate residual data for the current video block by subtracting (or more) predicted video blocks from the current video block. The residual data for the current video block may include residual video blocks corresponding to different sample components of the samples in the current video block.

[0246] In other examples, such as in skip mode, there may be no residual data for the current video block, and the residual generation unit 4407 may not perform subtraction operations.

[0247] The transform processing unit 4408 can generate one or more transform coefficient video blocks for the current video block by applying one or more transforms to the residual video blocks associated with the current video block.

[0248] After the transform processing unit 4408 generates a transform coefficient video block associated with the current video block, the quantization unit 4409 can 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.

[0249] The inverse quantization unit 4410 and the inverse transform unit 4411 can apply inverse quantization and inverse transform to the transform coefficient video block respectively to reconstruct the residual video block from the transform coefficient video block. The reconstruction unit 4412 can add the reconstructed residual video block to the corresponding sample points of one or more predicted video blocks generated by the prediction unit 4402 to generate a reconstructed video block associated with the current block and store it in the buffer 4413.

[0250] After the video block is reconstructed by reconstruction unit 4412, a loop filtering operation can be performed to reduce video block artifacts in the video block.

[0251] Entropy encoding unit 4414 can receive data from other functional components of video encoder 4400. When entropy encoding unit 4414 receives data, it can perform one or more entropy encoding operations to generate entropy-encoded data and output a bitstream including the entropy-encoded data.

[0252] Figure 6 is a block diagram illustrating an example of a video decoder 4500, which may be the video decoder 4324 in the system 4300 shown in Figure 4. The video decoder 4500 may be configured to perform any or all of the techniques disclosed herein. In the example shown, the video decoder 4500 includes multiple functional components. The techniques 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 techniques described in this disclosure.

[0253] In the example shown, the video decoder 4500 includes an entropy decoding unit 4501, a motion compensation unit 4502, an intra-frame prediction unit 4503, an inverse quantization unit 4504, an inverse transform unit 4505, a reconstruction unit 4506, and a buffer 4507. In some examples, the video decoder 4500 can perform a decoding process that is generally contrasted with the encoding process described with respect to the video encoder 4400.

[0254] The entropy decoding unit 4501 can retrieve the encoded bitstream. The encoded bitstream may include entropy-encoded video data (e.g., encoded video data blocks). The entropy decoding unit 4501 can decode the entropy-encoded video data, and based on the entropy-decoded video data, the motion compensation unit 4502 can determine motion information including motion vectors, motion vector precision, reference image list index, and other motion information. The motion compensation unit 4502 can determine this information, for example, by executing AMVP and Merge modes.

[0255] The motion compensation unit 4502 can generate motion compensation blocks and can perform interpolation based on an interpolation filter. The identifier of the interpolation filter to be used, with sub-pixel accuracy, can be included in the syntax element.

[0256] The motion compensation unit 4502 can use interpolation filters, such as those used by the video encoder 4400 during the encoding of a video block, to calculate interpolations for sub-integer pixels of a reference block. The motion compensation unit 4502 can determine the interpolation filter used by the video encoder 4400 based on the received syntax information, and the motion compensation unit 4502 can use the interpolation filter to generate a prediction block.

[0257] The motion compensation unit 4502 may use some syntax information to determine the size of the blocks of (multiple) frames and / or (multiple) stripes used to encode the encoded video sequence, segmentation information describing how each macroblock of the picture of the encoded video sequence is segmented, a mode indicating how each segment is encoded, one or more reference frames (and a list of reference frames) for each inter-frame codec block, and other information for decoding the encoded video sequence.

[0258] Intra-prediction unit 4503 can use, for example, an intra-prediction mode received in the bitstream to form prediction blocks from spatially adjacent blocks. Inverse quantization unit 4504 performs inverse quantization (i.e., dequantization) on the quantized video block coefficients provided in the bitstream and decoded by entropy decoding unit 4501. Inverse transform unit 4505 applies the inverse transform.

[0259] The reconstruction unit 4506 can sum the residual block with the corresponding predicted block generated by the motion compensation unit 4502 or the intra-frame prediction unit 4503 to form a decoded block. If necessary, a deblocking filter can also be used to filter the decoded block to remove block artifacts. The decoded video block is then stored in a buffer 4507, which provides a reference block for subsequent motion compensation / intra-frame prediction and also generates decoded video for presentation on a display device.

[0260] Figure 7 is a schematic diagram of an example encoder 4600. Encoder 4600 is suitable for implementing VVC techniques. Encoder 4600 includes three loop filters: a deblocking filter (DF) 4602, a sample adaptive compensation (SAO) 4604, and an adaptive loop filter (ALF) 4606. Unlike DF 4602, which uses predefined filters, SAO 4604 and ALF 4606 utilize the original samples of the current image to reduce the mean square error between the original and reconstructed samples, respectively, by adding an offset and by applying a finite impulse response (FIR) filter, where the side information of the encoding and decoding is transmitted via the offset and filter coefficients. ALF 4606 is located in the last processing stage of each image and can be considered as a tool to attempt to capture and repair artifacts caused by previous stages.

[0261] The encoder 4600 also includes an intra-frame prediction component 4608 and a motion estimation / compensation (ME / MC) component 4610 configured to receive input video. The intra-frame prediction component 4608 is configured to perform intra-frame prediction, while the ME / MC component 4610 is configured to perform inter-frame prediction using reference images obtained from a reference image buffer 4612. Residual blocks from inter-frame or intra-frame prediction are fed into a transform (T) component 4614 and a quantization (Q) component 4616 to generate quantized residual transform coefficients, which are then fed into an entropy coding component 4618. The entropy coding component 4618 entropy-codes the prediction results and the quantized transform coefficients and transmits them toward a video decoder (not shown). The quantization component output from the quantization component 4616 can be fed into an inverse quantization (IQ) component 4620, an inverse transform component 4622, and a reconstruction (REC) component 4624. REC component 4624 is able to output images to DF 4602, SAO 4604 and ALF 4606 for filtering before these images are stored in reference image buffer 4612.

[0262] The following is a list of some preferred solutions.

[0263] The following solutions illustrate examples of the techniques discussed in this article.

[0264] 1. A method for processing media data, comprising: determining a signal transmission identifier or a syntax element named po_id in an SEI processing sequence message to identify a set of SEI message types, for which a preferred processing order is indicated in the SEI processing sequence message; and performing a conversion between visual media data and a bitstream based on the identifier.

[0265] 2. The method of claim 1, wherein the specified post-processing filter (PPF) can be indicated by an SEI message with a payloadType value in SeiProcessingOrderSeiList.

[0266] 3. The method according to claim 1 or 2, wherein for each image, there may be multiple PPFs that are active and belong to one or more PPF groups; the PPF groups are interchangeable, i.e., at most one group can be selected to be applied.

[0267] 4. The method according to any one of claims 1-3, wherein the special PPF cascading case is defined as the case where both PPFs are activated for an image: both PPFs are NNPFs (i.e., the payloadType value of the NNPF indicates the neural network post-processing filter feature SEI message), one of the two NNPFs has nnpfc_purpose equal to 4 and the other has multiple input images, and neither NNPF is associated with the SEI processing order SEI message. In this case, the two NNPFs are implicitly considered to belong to a PPF group, and the NNPF with nnpfc_purpose equal to 4 is applied first.

[0268] 5. The method according to any one of claims 1-4, wherein other special PPF cascade cases may be defined.

[0269] 6. The method according to any one of claims 1-5, wherein how these special cases are handled (e.g., whether they are in a PPF group, the PPF processing order) is fixed and not indicated in the bit stream / transmitted via signal.

[0270] 7. The method according to any one of claims 1-6, wherein how to handle these special cases can still be indicated / transmitted via signals in the bitstream, but the indicated / transmitted information is ignored, and a predefined processing method is applied.

[0271] 8. The method according to any one of claims 1-7, wherein the order in which the PPF is applied in these particular cases is predefined, and the bitstream consistency requirement is that the indicated order must be the same as the predefined order.

[0272] 9. The method according to any one of claims 1-8, wherein, except in the case of special PPF cascading, each PPF group comprising multiple PPFs is associated with an SEI processing sequence SEI message having a specific value of a syntax element (e.g., named po_id).

[0273] 10. The method according to any one of claims 1-9, wherein, in all cases, each group of PPFs comprising a plurality of PPFs is associated with an SEI processing order SEI message having a specific value of a syntax element (e.g., po_id).

[0274] 11. The method according to any one of claims 1-10, wherein, except in special PPF cascading cases, any PPF not associated with the SEI message in the SEI processing order is in its own PPF group.

[0275] 12. The method according to any one of claims 1-11, wherein in all cases, any PPF not associated with the SEI message in the SEI processing order is in its own PPF group.

[0276] 13. The method according to any one of claims 1-12, wherein one or more PPFs from the selected PPF group can be applied. When multiple PPFs are applied (within the selected PPF group), they are applied in a cascading manner, meaning that they are applied in the order indicated by the SEI processing order SEI message associated with the selected PPF group, and for each applied PPF that is not the last applied PPF, the output is used as the input to the next applied PPF.

[0277] 14. The method according to any one of claims 1-13, wherein one or more PPFs from a selected PPF group may be applied. When multiple PPFs are applied (within a selected PPF group), they are applied in a cascading manner, meaning that they are applied in the order indicated by the SEI processing order SEI message associated with the selected PPF group, and for each PPF that is not the last PPF applied, the output image(s) is used as the input image(s) of the next PPF applied.

[0278] 15. The method according to any one of claims 1-14, wherein color transformation information SEI messages associated with different SEI processing orders must have different color_transform_id values.

[0279] 16. The method according to any one of claims 1-15, wherein the constraint is specified as follows: for any two SEI processing orders present in CVS, SEI messages spoSeiA and spoSeiB, when spoSeiA contains an entry where po_sei_payload_type[i] equals 142 (i.e., the payloadType of the color transformation information SEI message) and spoSeiB contains an entry where po_sei_payload_type[j] equals 142, i and j may be the same or different, po_sei_prefix_flag[i] in spoSeiA and po_sei_prefix_flag[j] in spoSeiB must both be equal to 1, and the value of the colour_transform_id syntax element contained in the SEI prefix indication of the i-th entry in spoSeiA should not be equal to the value of the colour_transform_id syntax element contained in the SEI prefix indication of the j-th entry in spoSeiB. The same applies when po_sei_wrapping_flag[i] in sposeiA or po_sei_wrapping_flag[j] in sposeiB is equal to 1. In this case, the colour_transform_id syntax element is directly included in the encapsulated SEI message.

[0280] 17. The method according to any one of claims 1-16, wherein the neural network post-processing filter characteristics constrained to SEI messages associated with different SEI processing orders must have different nnpfc_id values.

[0281] 18. The method according to any one of claims 1-17, wherein the constraint is specified as follows: for any two SEI processing orders SEI messages spoSeiA and spoSeiB existing in CVS, when spoSeiA contains an entry where po_sei_payload_type[i] equals 210 (i.e., the payloadType of the neural network post-processing filter feature SEI message) and spoSeiB contains an entry where po_sei_payload_type[j] equals 210, i and j may be the same or different, po_sei_prefix_flag[i] in spoSeiA and po_sei_prefix_flag[j] in spoSeiB must both be equal to 1, and the value of the nnpfc_id syntax element contained in the SEI prefix indication of the i-th entry in spoSeiA should not be equal to the value of the nnpfc_id syntax element contained in the SEI prefix indication of the j-th entry in spoSeiB. The same applies when po_sei_wrapping_flag[i] in sposeiA or po_sei_wrapping_flag[j] in sposeiB is equal to 1. In this case, the nnpfc_id syntax element is directly included in the encapsulated SEI message.

[0282] 19. The method according to any one of claims 1-8, wherein the NNPFA SEI message is extended to enable activation of the NNPF for a specific PPF group.

[0283] 20. The method according to any one of claims 19, wherein in an NNPFA SEI extension, the NNPF of a specific PPF group having the po_id can also be activated by signaling po_id.

[0284] 21. The method according to any one of claims 1-20, wherein a new activation SEI message is specified for non-NN PPF.

[0285] 22. The method according to any one of claims 1-21, wherein in a new activation SEI message, the id of a non-NN PPF can be transmitted at least by signaling.

[0286] 23. The method according to any one of claims 1-22, wherein the non-PPF SEI message itself is extended to enable activation of a PPF for a specific PPF group.

[0287] 24. The method according to any one of claims 1-23, wherein, constrained within the SEI processing order SEI message, at most one SEI message type can indicate a post-processing filter that will interpolate the image at application time.

[0288] 25. The method according to any one of claims 1-24, wherein, constrained within the SEI processing order SEI messages, only the last SEI message type can indicate a post-processing filter that will interpolate the image at application time.

[0289] 26. The method according to any one of claims 1-25, wherein the preferred processing order of PPFs that will interpolate the image during application is not explicitly transmitted via signaling, but is presumed to be the order of the penultimate PPF plus one.

[0290] 27. The method according to any one of claims 1-26, wherein a flag (e.g., named po_last_ppf_picture_interpolation_flag) is added outside the loop "for( i = 0, i < po_num_sei_messages_minus2 + 2; i++)", and po_sei_processing_order[ i ] is conditional on "if( ( i < po_num_sei_messages_minus2 + 1 ) || !po_last_ppf_picture_interpolation_flag )", and the value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to po_sei_processing_order[ po_num_sei_messages_minus2 ] + 1.

[0291] 28. The method according to any one of claims 1-27, wherein the flag po_last_ppf_picture_interpolation_flag is not transmitted via signaling, but a variable (e.g., named PoLastPpfPictureInterpolationFlag) is deduced based on the SEI payloadType and the SEI prefix indication of the last entry (if present), which indicates whether the last PPF will interpolate the picture when applied, and po_sei_processing_order[i] is conditional on "if ( (i < po_num_sei_messages_minus2 + 1) || ! PoLastPpfPictureInterpolationFlag )", and the value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to po_sei_processing_order[ po_num_sei_messages_minus2 ] + 1.

[0292] 29. The method according to any one of claims 1-28, wherein the syntax element po_num_prefix_bytes[i] is changed to po_num_prefix_bytes_minus1[i], that is, the number of prefix bytes transmitted by signaling is reduced by 1 instead of the number of prefix bytes transmitted by signaling.

[0293] 30. The method according to any one of claims 1-29, wherein the syntax element po_num_prefix_bytes[i] remains unchanged, po_sei_prefix_flag is removed, and whether the prefix is ​​available depends on whether po_num_prefix_bytes[i] is zero.

[0294] 31. An apparatus for processing video data, comprising a processor and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform the method according to any one of claims 1-30.

[0295] 32. A non-transitory computer-readable medium comprising a computer program product for use by a video codec apparatus, the computer program product comprising computer-executable instructions stored on the non-transitory computer-readable medium, such that the computer-executable instructions, when executed by a processor, cause the video codec apparatus to perform the method according to any one of claims 1-30.

[0296] 33. A non-transitory computer-readable recording medium for storing a bitstream of video generated by a method performed by a video processing apparatus, wherein the method comprises: determining a signal transmission identifier or a syntax element named po_id in an SEI processing sequence (SEI) message to identify a set of SEI message types, indicating a preferred processing order in the SEI processing sequence (SEI) message for the set of SEI message types; and generating a bitstream based on the determination.

[0297] 34. A method for storing a bitstream of video, comprising: determining a set of SEI message types by means of a signal transmission identifier or a syntax element named po_id in an SEI processing sequence message, indicating a preferred processing order in the SEI processing sequence message for the set of SEI message types; generating a bitstream based on the determination; and storing the bitstream in a non-transitory computer-readable recording medium.

[0298] 35. A method, apparatus or system described in this disclosure.

[0299] In the described solution, the encoder conforms to the format rules by generating an encoded representation based on those rules. In the described solution, the decoder parses the syntax elements in the encoded representation using known information about their presence or absence, based on the format rules, to generate the decoded video.

[0300] In this disclosure, the term "video processing" can refer to video encoding, video decoding, video compression, or video decompression. For example, a video compression algorithm can be applied during the conversion from a pixel representation of a video to a corresponding bitstream representation, and vice versa. For example, the bitstream representation of the current video block can correspond to bits at co-positions or propagated at different positions in a bitstream defined by a syntax. For example, a macroblock can be encoded based on the error residual values ​​after transformation and encoding / decoding, and can also use bits from the header and other fields in the bitstream. Furthermore, during the conversion, the decoder can parse the bitstream based on the determination, knowing whether some fields may or may not be present, as described in the solutions above. Similarly, the encoder can determine whether to include or exclude specific syntax fields and generate an encoding / decoding representation accordingly by including or excluding syntax fields from the encoded / decoded representation.

[0301] The disclosed and other solutions, examples, embodiments, modules, and functional operations described herein can be implemented in digital electronic circuits, or in computer software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in one or more combinations thereof. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more computer program instruction modules encoded on a computer-readable medium for execution by or control of the operation of a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a material composition affecting machine-readable propagation signals, or one or more combinations thereof. The term "data processing apparatus" includes all means, devices, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus may also include code that creates an execution environment for an associated computer program, for example, code constituting processor firmware, a protocol stack, a database management system, an operating system, or one or more combinations thereof. Propagation signals are artificially generated signals, such as machine-generated electrical, optical, or electromagnetic signals, which are generated to encode information to be transmitted to a suitable receiver device.

[0302] Computer programs (also known as programs, software, software applications, scripts, or code) can be written in any programming language, including compiled or interpreted languages, and can be deployed in any form, including standalone programs or modules, components, subroutines, or other units 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 related program, or in multiple co-located files (e.g., a file storing one or more modules, subroutines, or code portions). A computer program can be deployed to execute on one computer or on multiple computers located at a single site or distributed across multiple sites and interconnected by a communications network.

[0303] The processing and logic flows described in this disclosure can be executed by one or more programmable processors that execute one or more computer programs to perform functions by manipulating input data and generating outputs. The processing and logic flows can also be executed by special-purpose logic circuitry, and the apparatus can also be implemented as special-purpose logic circuitry, such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0304] Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors, and any one or more processors in any type of digital computer. Typically, the processor receives instructions and data from read-only memory or random access memory, or both. The basic components of a computer are a processor that executes instructions and one or more storage devices that store the instructions and data. Typically, a computer will also include one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks. However, a computer does not necessarily have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor storage devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable hard disks; magneto-optical disks; and CD-ROMs and DVD-ROMs. The processor and memory may be supplemented by or incorporated into special-purpose logic circuitry.

[0305] While this disclosure contains numerous details, these details should not be construed as limiting any subject matter or the scope of the claims, but rather as descriptions of features specific to particular embodiments of a particular art. Certain features described in the context of individual embodiments in this disclosure may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments, or in any suitable sub-combination. Furthermore, although features may function in certain combinations as described above, and even were originally claimed in this manner, in some cases one or more features in the claimed combination may be removed from that combination, and the claimed combination may be for sub-combinations or variations thereof.

[0306] Similarly, although operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed sequentially in the particular order or sequence shown, or requiring all shown operations to be performed in order to achieve the desired result. Furthermore, the partitioning of various system components in the embodiments described in this disclosure should not be construed as requiring such partitioning in all embodiments.

[0307] Only a few implementations and examples are described, and other implementations, improvements and variations may be made based on what is described and shown in this disclosure.

[0308] When there are no intermediate components other than a line, trace, or other medium between the first and second components, the first component is directly coupled to the second component. When there are intermediate components other than a line, trace, or other medium between the first and second components, the first component is indirectly coupled to the second component. The term "coupled" and its variations include direct coupling and indirect coupling. The use of the term "about" means including a range of ±10% of the following figures, unless otherwise specified.

[0309] While several embodiments have been provided in this disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of this disclosure. The present examples are to be considered illustrative rather than restrictive and are not intended to be limited to the details set forth herein. For example, various elements or components may be combined or integrated into another system, or certain features may be omitted or not implemented.

[0310] Furthermore, the technologies, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, technologies, or methods without departing from the scope of this disclosure. Other items shown or discussed as couplings may be directly connected or indirectly coupled or communicated through some interface, device, or intermediate component (whether electrical, mechanical, or otherwise). Those skilled in the art can identify examples of other changes, substitutions, and modifications, which may be made without departing from the spirit and scope of this disclosure.

Claims

1. A method for processing media data, comprising: The process determines the order of supplemental enhancement information (SEI) processing (SPO) SEI message, which includes a syntax element containing an identifier to identify the SPO SEI message; and performs a conversion between visual media data and a bitstream based on the syntax element.

2. The method as described in claim 1, wherein, The SPO SEI message carries information indicating the preferred processing order of a set of SEI message types in the encoded and decoded video sequence.

3. The method as described in claim 1 or 2, wherein, The syntax element is specified as po_id.

4. The method according to any one of claims 1-3, wherein, Only one SEI message type within the SPO SEI message is allowed to indicate a post-processing filter for interpolating the image at application time.

5. The method according to any one of claims 1-3, wherein, Only the last SEI message type indication within the SPO SEI message is allowed to be a post-processing filter that interpolates the image at application time.

6. The method according to any one of claims 1-5, wherein, The preferred processing order of the post-processing filter (PPF) that interpolates the image at application time is not explicitly transmitted via signal in the bitstream.

7. The method according to any one of claims 1-6, wherein, The preferred processing order of the PPF used for image interpolation during application is presumably the penultimate PPF's indication order plus one.

8. The method according to any one of claims 1-7, wherein, The po_last_ppf_picture_interpolation_flag is added outside the following loop: for( i = 0, i < po_num_sei_messages_minus2 + 2; i++), where the po_last_ppf_picture_interpolation_flag indicates that the last SEI message type in the SPO SEI message indicates the PFF that interpolates the picture at the time of application.

9. The method according to any one of claims 1-8, wherein, po_sei_processing_order[i] is conditional as follows: if( (i < po_num_sei_messages_minus2 + 1) || !po_last_ppf_picture_interpolation_flag), where po_num_sei_messages_minus2 indicates the number of SEI messages having the processing order indicated in the SPO SEI message.

10. The method of claim 9, wherein, The value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to the value of po_sei_processing_order[ po_num_sei_messages_minus2 ] plus 1.

11. The method according to any one of claims 1-10, wherein, The po_last_ppf_picture_interpolation_flag is not transmitted via signal in the bitstream.

12. The method according to any one of claims 1 to 11, wherein, The variable PoLastPpfPictureInterpolationFlag is derived based on the SEI payloadType and the SEI prefix indication of the last entry (if present), where the SEI prefix indication indicates whether the last PPF interpolates the image when applied.

13. The method according to any one of claims 1-12, wherein, po_sei_processing_order[i] is conditional as follows: if( (i < po_num_sei_messages_minus2 + 1) || !PoLastPpfPictureInterpolationFlag), where po_num_sei_messages_minus2 indicates the number of SEI messages having the processing order indicated in the SPO SEI messages.

14. The method of claim 13, wherein, The value of po_sei_processing_order[ po_num_sei_messages_minus2 + 1 ] is presumed to be equal to the value of po_sei_processing_order[ po_num_sei_messages_minus2 ] plus 1.

15. The method according to any one of claims 1-14, wherein, The value of the syntax element minus 1 specifies the amount of data associated with the i-th SEI message processed according to the preferred processing order identified in the SPOSEI message.

16. The method of claim 15, wherein, The amount of data includes bytes or bits.

17. The method of claim 15 or 16, wherein, The syntax element is specified as po_num_bits_in_prefix_indication_minus1[i].

18. The method according to any one of claims 1-14, wherein, The value of the syntax element specifies the amount of data associated with the i-th SEI message processed according to the preferred processing order identified in the SPOSEI message.

19. The method of claim 18, wherein, The SPO SEI message does not include the SEI prefix flag to indicate the presence of the syntax element.

20. The method of claim 18 or 19, wherein, The prefix is ​​unavailable when the syntax element has a zero value.

21. The method according to any one of claims 18-20, wherein, When the syntax element is not present in the bitstream, the syntax element is presumed to have a zero value.

22. The method according to any one of claims 1-21, wherein, The conversion includes encoding the media data into the bitstream.

23. The method according to any one of claims 1-21, wherein, The conversion includes decoding the media data from the bitstream.

24. An apparatus for processing video data, comprising a processor and a non-transitory memory having instructions thereon, wherein, When executed by the processor, the instructions cause the processor to perform the method as described in any one of claims 1-23.

25. A non-transitory computer-readable medium comprising a computer program product for use with a video encoding / decoding device, wherein, The computer program product includes computer-executable instructions stored on the non-transitory computer-readable medium, such that when executed by a processor, the computer-executable instructions cause the video codec device to perform the method as described in any one of claims 1-23.

26. A non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by a video processing apparatus, wherein, The method includes: determining a Supplemental Enhancement Information (SEI) Processing Order (SPO) SEI message including syntax elements, wherein the syntax elements contain an identifier to identify the SPO SEI message; and performing a conversion between visual media data and a bitstream based on the syntax elements.

27. A method for storing a video bitstream, comprising: The process involves determining a Supplemental Enhancement Information (SEI) Processing Order (SPO) SEI message, which includes a syntax element containing an identifier to identify the SPO SEI message; generating the bitstream having the SPO SEI message including the syntax element; and storing the bitstream in a non-transitory computer-readable recording medium.

28. A method, apparatus or system described in this disclosure.

Images