RU2780809C1 - Signalling of the image header parameters - Google Patents

Abstract

FIELD: video data processing.

SUBSTANCE: group of inventions relates to video encoding/decoding and generally describes the technology of new-generation video encoding; in particular, generally relates to methods and apparatus associated with processing an image header. Proposed is a method for video data decoding, wherein the method is implemented by at least one processor. The method includes a stage of indicating, using the syntax element of the image header, for all slices included in the corresponding encoded image, whether said slices are type B, P, and/or I slices, wherein the syntax element is encoded using an unsigned integer. The video data is decoded based on the types of slices indicated by means of the syntax element.

EFFECT: reduced amount of signalling service data when indicating the slice type.

12 cl, 18 tbl, 3 dwg

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62/950,453, filed December 19, 2019, and U.S. Provisional Application No. 17/026,748, filed September 21, 2020, which are incorporated herein in their entirety.

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[0002] This invention relates generally to video coding/decoding and generally describes next-generation video coding technologies in relation to HEVC (high performance video coding, High Efficiency Video Coding), such as Versatile Video Coding (VVC). In particular, this invention relates generally to methods and apparatuses related to image header processing.

BACKGROUND OF THE INVENTION

[0003] VVC Proposed Draft 7 includes an HLS (High Level Syntax, High Level Syntax), referred to as a picture header, which contains syntax elements that apply to all slices of an encoded picture, for example, to avoid signaling syntax elements in the slice header(s). (s), which must have the same values for all slices of the image.

Image parameter set

[0004] The HLS defines syntax elements that can be applied to lower level encoding tools. For example, the size of the CTU (Coding Tree Unit) can be set at the level of sequences or SPS (Sequence Parameter Sets), and generally does not change from image to image. A typical HLS includes SPS, PPS (Picture Parameter Set), PH (Picture Header), SH (Slice Header), and APS (Adaptive Parameter Set).

[0005] The various HLSs include application layers so that commonly used syntax elements do not need to be re-encoded. For example, SPS defines common syntax elements that apply to sequence levels. The PH specifies the general syntax elements applicable to the encoded picture, which may consist of one or more slices.

[0006] The syntax elements included in the PPS according to VVC Draft 7 are described below:

[0007] As shown in Table 1 above, num_slices_in_pic_minus1 plus 1 specifies the number of rectangular slices in each image referring to PPS. The value of num_slices_in_pic_minus1 is between 0 and MaxSlicesPerPicture - 1, inclusive. When no_pic_partition_flag is equal to 1, the value of num_slices_in_pic_minus1 may be determined to be 0.

[0008] As shown in Table 1 above, pps_mvd_1l_zero_idc equal to 0 indicates that the mvd_l1_zero_flag syntax element is present in the PH referring to the PPS. In addition, pps_mvd_1l_zero_idc equal to 1 or 2 indicates that the mvd_l1_zero_flag is not present in the PPS referenced PHs. Additionally, pps_mvd_l1_zero_idc equal to 3 is reserved for future use in ITU-T ISO/IEC.

[0009] As shown in Table 1 above, pps_collocated_from_10_idc equal to 0 indicates that the collocated_from_10_flag syntax element is present in slice headers referring to PPS. In addition, pps_collocated_from_10_idc equal to 1 or 2 indicates that the collocated_from_10_flag syntax element is not present in the slice headers referring to PPS. Additionally, pps_collocated_from_10_idc equal to 3 is reserved for future use in ITU-T | ISO/IEC.

[0010] As shown in Table 1 above, pps_six_minus_max_num_merge_cand_plus1 equal to 0 indicates that picsixminusmaxnummergecand is present in the PPS referencing PH. In addition, pps_six_minus_max_num_merge_cand_plus1 greater than 0 indicates that pps_six_minus_max_num_merge_cand is not present in PPS referencing PHs. The value of pps_six_minus_max_num_merge_cand_plus1 is between 0 and 6, inclusive.

[0011] As shown in Table 1 above, pps_max_num_merge_cand_minus_max_num_triangle_cand_plus1 equal to 0 indicates that pic_max_num_merge_candminus_max_num_triangle_cand is present in the PH of slices referring to PPS. In addition, pps_max_num_merge_cand_minus_max_num_triangle_cand_plus1 greater than 0 indicates that pic_max_num_merge_candminus_max_num_triangle_cand is not present in PPS referenced RNs. The value of pic_max_num_merge_candminus_max_num_triangle_cand_plus1 is between 0 and MaxNumMergeCand - 1.

slice level RBSP

[0012] A slice level RBSP may consist of a slice header and slice data.

Image title and slice title

[0013] Syntax elements encoded in the PPS referenced by the current picture must be ignored in the PH and SH, resulting in pic_deblocking_filter_override_flag being set in the PH referring to the PPS, or slice_deblocking_filter_override_flag in the SH referring to the PPS. Syntactic elements not present in PH may, on the contrary, be present in SH. For example, when the value of pic_sao_enabled_present_flag in PH indicating the presence of syntax elements associated with SAO is 0, slice_sao_luma_flag and slice_sao_chroma_flag may be encoded in SH to indicate the use of SAO for luma and chrominance.

[0014] Using the PH, syntax elements that should already be the same in all slices of an image can be transferred to the PH one per image to avoid signaling overhead, especially when there are few slices in the image. Still, syntax elements that change frequently from slice to slice can be passed to SH for flexibility.

[0015] The syntax elements included in the PH and SH according to VVC Draft 7 are described in Tables 3 and 5 below.

[0016] As mentioned above and below, slice type may indicate a slice encoding type according to Table 4 below:

Access Block Separator

[0017] The AU separator (Access Unit) is used to indicate the beginning of the AU and the type of slices present in the encoded pictures in the AU containing the NAL (Network Abstraction Layer) AU separator. There is currently no normative decoding process associated with the AU delimiter.

[0018] In addition, pic_type indicates that slice_type values for all coded picture slices in the AU containing the AU delimiter NAL unit are the elements of the set listed in Table 4 for the given pic_type value. The value of pic_type can be 0, 1, or 2 in bitstreams. Other pic_type values are reserved for future use by ITU T | ISO/IEC. Decoders conforming to this version MAY ignore reserved pic_type values.

[0019] Non-Patent Reference [1] proposes a high-level control flag to indicate that a set of parameters is needed for the covered low-level coding levels.

[0020] [1] describes a method in which all syntax elements or parameters associated with inter-prediction need only be signaled when there is at least one inter-coded slice, or when a split exists within an image. Otherwise, these syntax elements or parameters are not signaled.

[0021] In one embodiment described in [1], a control flag in the picture header, denoted pic_intra_only_flag, is signaled to indicate whether all slices (or any kind of parts of that picture) within the picture will only have intra prediction (or not be associated with internal prediction). When this flag is TRUE, only syntax elements or parameters related to intra-coding are signaled later in the picture header. Otherwise, when this flag is FALSE, syntax elements or parameters associated with inter prediction are signaled. The following is a syntax table reflecting this embodiment:

[0022] According to another method from [1], all associated syntax elements or parameters that are only used for intra-slice or intra-splitting need to be signaled in the absence of an inter-coded slice, or when a split exists within an image. Otherwise, these syntax elements or parameters are not signaled.

[0023] In another embodiment [1], a control flag in the image header, denoted pic_inter_only_flag, is signaled to indicate whether all slices (or any kind of partition of that image) within the image will have inter-prediction (or prediction unrelated to intra-prediction). ). When this flag is TRUE, syntax elements or parameters associated with an intra-slice are not signaled later in the image header. Otherwise, when this flag is FALSE, the intra-slice may be used in at least one of the slices or partitions in the image. The associated syntax elements or parameters for the intra-slice or parts will be signalled. The following is a syntax table reflecting this embodiment:

[0024] According to the methods described in [1], if the image has its own type, for example, is an intra-image or an inter-image, the aforementioned control flags pic_intra_only_flag and pic_inter_only_flag do not need to be signaled, and their values can be derived from the image type.

[0025] In addition, if the current picture is of the intra-only picture type (all slices in the picture are I-slices), then pic_intra_only_flag may be determined to be TRUE. In another example, if the current picture is of the inter-only picture type (all slices in the picture are P or B slices), then pic_inter_only_flag may be defined as TRUE. In yet another example in [1], if the current picture has a picture type indicating that both intra-slices and inter-slices are possible in the picture, then pic_intra_only_flag and pic_inter_only_flag may be defined as FALSE.

Problem

[0026] Although the PH may be signaled one per picture to avoid signaling syntax elements that are common to slices within a picture, this signaling may instead introduce overhead by not considering syntax elements used only for intra-slices (I -slices) or inter-slices (B-, P-slices).

SUMMARY OF THE INVENTION

[0027] Embodiments relate to a method, system, and computer-readable medium for encoding/decoding video, and in particular to image header processing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and other objects, features, and advantages will be apparent from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawings. Various features of the drawings may be drawn out of scale for clarity and ease of understanding by one of ordinary skill in the art, together with a detailed description. On the drawings:

[0029] FIG. 1 is a simplified block diagram of a communication system in accordance with an embodiment.

[0030] FIG. 2 is a simplified block diagram of a communication system in accordance with an embodiment.

[0031] FIG. 3 is a diagram of a computer system in accordance with an embodiment.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a simplified block diagram of a communication system (100) according to an embodiment of the present invention. System (100) may include at least two terminals (110-120) interconnected via network (150). For unidirectional data transmission, the first terminal (110) may encode video data at the local location for transmission to another terminal (120) via the network (150). The second terminal (120) may receive another terminal's encoded video data from the network (150), decode the encoded data, and display the recovered video data. One-way communication may be inherent in media service applications and the like.

[0033] FIG. 1 shows a second pair of terminals (130, 140) provided to support bidirectional transmission of coded video, which may occur, for example, during a video conference. For bi-directional data transmission, each terminal (130, 140) may encode the video data captured at the local location for transmission to another terminal via the network (150). Each terminal (130, 140) may also receive the encoded video data transmitted by the other terminal, may decode the encoded data, and display the reconstructed video data on a local display device.

[0034] FIG. 1, terminals (110-140) may be illustrated as servers, personal computers, and smartphones, but this does not limit the principles of the present invention. Embodiments of the present invention find application in laptop computers, tablet computers, media players and/or dedicated video conferencing equipment. Network (150) represents any number of networks that carry encoded video data between terminals (110-140), including, for example, wired and/or wireless networks. The communication network (150) allows data to be exchanged in a circuit-switched and/or packet-switched mode. Exemplary networks include telecommunications networks, local area networks, wide area networks, and/or the Internet. For the purposes of this discussion, the architecture and topology of the network (150) may not be relevant to the present invention unless specifically noted below.

[0035] FIG. 2 shows, as an example of the application of the disclosed invention, the placement of a video encoder and decoder in a streaming environment. The disclosed invention may be equally applicable to other video processing applications, including, for example, videoconferencing, digital television, storage of compressed video on digital media, including CD, DVD, memory card, etc., etc.

[0036] The streaming system may include a capture subsystem (213), which may include a video signal source (201), such as a digital camera, producing, for example, an uncompressed video sample stream (202). This stream (202) of samples, depicted with a thick line to emphasize the high amount of data compared to the bitstreams of the encoded video, can be processed by the encoder (203) connected to the camera (201). The encoder (203) may include hardware, software, or a combination thereof for providing or implementing aspects of the disclosed invention, as described in more detail below. The encoded video bitstream (204), drawn with a thin line to emphasize the lower amount of data compared to the sample stream, may be stored on the streaming server (205) for future use. One or more streaming clients (206, 208) may access the streaming server (205) to retrieve copies (207, 209) of the encoded video bitstream (204). The client (206) may include a video decoder (210) that decodes an incoming copy of the encoded video bitstream (207) and produces an outgoing stream (211) of video samples that can be rendered on a display (212) or other renderer (not shown) . In some streaming systems, the video bitstreams (204, 207, 209) may be encoded according to one video coding/compression standard or another. Examples of these standards include ITU-T Recommendation H.265. A video coding standard is being developed, formally referred to as Universal Video Coding or VVC. The disclosed invention may be used in the context of VVC.

[0037] According to embodiments, the pic_type_idc syntax element may be used to indicate slice types for all slices of an encoded picture.

[0038] In one embodiment, pic_type_idc may be encoded using an unsigned integer syntax element encoded with a 0th order exponential Golomb code, starting from the left bit. While pic_type_idc can have three values 0, 1 and 2 and three states, for example, only I-slice, B-, P-, I-slices, and B-, P-slices. The value can appear in the states in any order. The following table 8 provides examples of the possible semantics of pic_type_idc.

[0039] According to an embodiment, pic_type_idc may be encoded using an unsigned integer using 2 bits. Here, pic_type_idc may have, but is not limited to, three values of 0, 1 and 2 and three states, for example: I-slice only, B-, P-, I-slices, and B-, P-slices. Other pic_type_idc values may be reserved for later reference.

[0040] According to an embodiment, the reserved value 3 pic_type_idc may indicate that only P and I slices are present in the encoded picture.

[0041] In the example, pic_type_idc may be encoded using an unsigned integer using 2 bits. In addition, pic_type_idc can have four values of 0, 1, 2, and 3 and four states, such as I-slice only, B-, P-, I-slices, and B-slices, and P-slices.

[0042] It is proposed to signal pic_type_idc in HLS so that only related syntax elements are encoded or present to reduce signaling overhead. For example, when pic_type_idc indicates that the picture is only an intra-picture (intra-coded), no syntax elements related to inter-coding (outer encoding) are signaled.

[0043] In one example, pic_type_idc may be signaled in the PPS such that it specifies slice types for all slices of each encoded picture referring to the PPS. The syntax and semantics are detailed below. In the following table, as well as other tables in this invention, changes from VVC draft 7 are in italics.

[0044] Here, pic_type_idc specifies slice types for all slices of each encoded picture referring to the PPS.

[0045] In one embodiment, pic_type_idc set to 1 indicates that each encoded picture referring to the PPS has only one or more I-slices. In such cases, the inter-slices (B-, P-slice) associated with the syntax elements pps_mvd_1l_zero_idc, pps_collocated_from_10_idc, pps_six_minus_max_num_merge_cand_plus1 and pps_max_num_merge_cand_minus_max_num_triangle_cand_plus1 are defined to be 0.

[0046] Here, pps_mvd_1l_zero_idc equal to 0 indicates that the mvd_l1_zero_flag syntax element is present in the RNs referring to the PPS. In addition, pps_mvd_l1_zero_idc equal to 1 or 2 indicates that the mvd ll zero flag is not present in the PHs referring to PPS. Additionally, pps_mvd_1l_zero_idc equal to 3 is reserved for future use in ITU-T | ISO/IEC. When absent, pps_mvd_1l_zero_idc may be set to 0.

[0047] Additionally, pps_collocated_from_10_idc equal to 0 indicates that the collocated_from_10_flag syntax element is present in slice headers referring to HaPPS. In addition, pps_collocated_from_10_idc equal to 1 or 2 indicates that the collocated from lO flag syntax element is not present in the slice headers referring to PPS. Additionally, pps_collocated_from_10_idc equal to 3 is reserved for future use in ITU-T | ISO/IEC. When absent, pps_collocated_from_10_idc may be set to 0.

[0048] In addition, pps_six_minus_max_num_merge_cand_plus1 equal to 0 indicates that pps_six_minus_max_num_merge_cand is present in the PH referring to the PPS. Additionally, pps_six_minus_max_num_merge_cand_plus1 greater than 0 indicates that pps_six_minus_max_num_merge_cand is not present in PPS-referencing PHs. The value of pps_six_minus_max_num_merge_cand_plus1 is between 0 and 6, inclusive. When absent, pps_six_minus_max_num_merge_cand_plus1 may be set to 0

[0049] As shown, pic_max_num_merge_candminus_max_num_triangle_cand_plus1 equal to 0 indicates that pic_max_num_merge_candminus_max_num_triangle_cand is present in the PH of slices referring to PPS. In addition, pic_max_num_merge_candminus_max_num_triangle_cand_plus1 greater than 0 indicates that pic_max_num_merge_candminus_max_num_triangle_cand is not present in PHs referring to PPS. The value of pps_max_num_merge_cand_minus_max_num_triangle_cand_plus1 ranges from 0 to MaxNumMergeCand - 1. When absent, pic_max_num_merge_candminus_max_num_triangle_cand_plus1 may be set to 0.

[0050] For each encoded picture referring to PPS, pic_type_idc is used to determine whether to parse syntax elements associated with intra-slices (I-slices) and inter-slices (B-, P-slices). For example, syntax elements associated with intra-slices

pic_log2_diff_min_qt_min_cb_intra_slice_luma,

pic_max_mtt_hierarchy_depth_intra_slice_luma,

pic_log2_diff_min_qt_min_cb_intra_slice_luma,

pic_log2_diff_min_qt_min_cb_intra_slice_luma,

pic_log2_diff_min_qt_min_cb_intra_slice_chroma,

pic_max_mtt_hierarchy_depth_intra_slice_chroma,

pic_log2_diff_max_bt_min_qt_intra_slice_chroma and

pic_log2_diff_min_qt_min_cb_intra_slice_chroma, decode only if there are only I-slices associated with the PH. On the other hand, syntax elements associated with inter-slices are decoded whenever inter-slices are present.

[0051] In one example, pic_type_idc is signaled to the PH whereby it specifies the slice types for all slices of the encoded picture associated with the PH. A detailed description of the syntax and semantics is given below. Changes from VVC draft 7 are in italics.

[0052] For each encoded picture, pic_type_idc is used to determine whether to analyze syntax elements associated with intra-slices (I-slices) and inter-slices (B-, P-slices). For example, the syntax elements associated with intra-slices are pic_log2_difr_min_qt_min_cb_intra_slice_luma,

pic_max_mtt_hierarchy_depth_intra_slice_luma,

pic_log2_diff_min_qt_min_qt_intra_slice_luma,

pic_log2_diff_min_qt_min_cb_intra_slice_luma,

pic_log2_diff_min_qt_min_cb_intra_slice_chroma,

pic_max_mtt_hierarchy_depth_intra_slice_chroma,

pic_log2_diff_max_bt_min_qt_intra_slice_chroma and

pic_log2_diff_min_qt_min_cb_intra_slice_chroma are decoded only if there are only I-slices associated with the RH. On the other hand, syntactic elements associated with inter-slices are decoded whenever inter-slices are present.

[0053] In one embodiment, pic_type_idc may be present in both the PPS and the PH referring to the PPS as pps_pic_type_idc and ph_pic_type_idc, respectively.

[0054] Here, pps_pic_type_idc specifies slice types for all slices of each encoded picture referring to the PPS.

[0055] In addition, pps_mvd_1l_zero_idc equal to 0 indicates that the mvd_l1_zero_flag syntax element is present in the RNs referring to the PPS. Additionally, pps_mvd_l1_zero_idc equal to 1 or 2 indicates that the mvd ll zero flag is not present in the RNs referring to PPS. Additionally, pps_mvd_l1_zero_idc equal to 3 is reserved for future use in ITU-T | ISO/IEC. When absent, pps_mvd_1l_zero_idc may be set to 0.

[0056] In addition, pps_collocated_from_10_idc equal to 0 indicates that the collocated from lO flag syntax element is present in the slice headers referring to the PPS. Additionally, pps_collocated_from_10_idc equal to 1 or 2 indicates that the collocated_from_10_flag syntax element is not present in the slice headers referring to the PPS. Additionally, pps_collocated_from_10_idc equal to 3 is reserved for future use in ITU-T | ISO/IEC. When absent, pps_collocated_from_10_idc may be set to 0.

[0057] In addition, pps_six_minus_max_num_merge_cand_plus1 equal to 0 indicates that pps_six_minus_max_num_merge_cand is present in the PH referring to the PPS. Additionally, pps_six_minus_max_num_merge_cand_plus1 greater than 0 indicates that pps_six_minus_max_num_merge_cand is not present in PPS-referencing PHs. The value of pps_six_minus_max_num_merge_cand_plus1 must be between 0 and 6, inclusive. When absent, pps_six_minus_max_num_merge_cand_plus1 may be set to 0.

[0058] In addition, pic_max_num_merge_candminus_max_num_triangle_candplus1 equal to 0 indicates that pic_max_num_merge_candminus_max_num_triangle_cand is present in the PH of slices referring to PPS. Additionally, pic_max_num_merge_candminus_max_num_triangle_candplus1 greater than 0 indicates that pic_max_num_merge_candminus_max_num_triangle_cand is not present in PPS-referencing PHs. The value of pps_max_num_merge_cand_minus_max_num_triangle_cand_plus1 shall be between 0 and MaxNumMergeCand - 1. When absent, pps_max_num_merge_cand_minus_max_num_triangle_cand_plus1 may be set to 0.

[0059] In one example, when the pps_pic_type_idc value indicates the presence of one slice type (I- or B- or P-slice, as in Table 10 value 1, 2, and 3), the ph_pic_type_idc value may be determined from the pps_pic_type_idc value.

[0060] Here, ph_pic_type_idc specifies slice types for all slices of each encoded picture associated with the PH.

[0061] In one embodiment, ph_tic_type_idc equal to 1 indicates that each encoded picture associated with the PH has only one or more I-slices.

[0062] If pps_pic_type_idc is 0 (B-, P-, I-slices as in Table 10), the value of ph_pic_type_idc is in the range 0 to 2, inclusive. Otherwise, the value of ph_pic_type_idc may be determined from pps_pic_type_idc (eg, identically). In such a case, the bitstream matching requirement is that the values of ph_pic_type_idc must be equal to the values of pps_pic_type_idc.

[0063] In one example, the ph_pic_type_idc syntax signaling is dependent on (eg, limited to) the pps_pic_type_idc value. When the value of pps_pic_type_idc indicates the presence of both intra-slices (I-slices) and inter-slices (B-, P-slices) in encoded pictures, ph_tic_type_idc needs to be signaled/parsed to indicate the slice types present in that picture associated with a header Images. In other cases, when pps_pic_type_idc indicates the presence of a single slice type, ph_pic_type_idc is not signaled/parsed, and is determined to be equal to (eg, identical to) the pps_pic_type_idc slice type. The bitstream matching requirement is that the range of ph_pic_type_idc is not greater than the range of pps_pic_type_idc.

[0064] Here, ph_pic_type_idc specifies slice types for all slices of each encoded picture associated with the PH. Also, ph_pic_type_idc can only be present in the bitstream when pps_pic_type_idc is 0.

[0065] Additionally, ph_pic_type_idc equal to 1 indicates that each encoded picture associated with the PH has only one or more I-slices. If pps_pic_type_idc is 0 (B-, P-, I-slices as in Table 8), the value of ph_tic_type_idc is in the range 0 to 2, inclusive. Otherwise, when ph_pic_type_idc is absent, it is determined to be pps_ph_type_idc as in Table 8.

[0066] In one embodiment, the syntax elements associated with the PH are included in the slice level RBSP NAL unit, and ph_present_flag is used to indicate the presence of the syntax associated with the PH in the slice level RBSP NAL unit. Resigning the RH-related syntax may have the benefit of error tolerance and error recovery. When a PH NAL becomes corrupted in transit over any kind of network, the slice layer RBSP NALs are capable of error recovery when there is a PH in the slice layer RBSP NALs. Changes from VVC draft 7 are in italics.

[0067] Here, the ph_present_flag may be used to indicate the presence of a PH-related syntax in a slice-level RBSP. When ph_present_flag is 1, the PH-related syntax is present. When the ph_present flag is 0, the PH-related syntax is not present in the slice level RBSP.

[0068] In one embodiment, when the pic_type decoded in the AU delimiter as described above is present, the pic_type_idc signaled in the HLS may be determined from or limited by the pic_type value.

[0069] In one example, when pic_type is 0, as in Table 5, indicating an I-slice, the bitstream matching requirement is that pic_type_idc values indicate that only intra-slices are present in each picture. For example, when it is agreed that pic_type_idc is 1, only intra-slices are present.

[0070] In one example, when pic_type_idc is limited to the value of pic_type, the range of the value of pic_type_idc may depend on the value of pic_type. For example, pic_type_idc has values as described in Table 10, and if pic_type is 1, pic_type_idc can have a value of 1 or 3. In other cases, when pic_type is 2, pic_type_idc is 0 to 3.

[0071] In one embodiment, when pic_type_idc is signaled in HLS according to the above method(s), slice_type can be determined.

[0072] In one example, when pic_type_idc has a value indicating only intra-slices, slice_type may be determined to be 2.

[0073] In one example, when pic_type_idc has a value indicating only inter-slices, the slice_type value is in the range 0 to 1, inclusive. For example, when pic_type_idc is 2 (B-, P-slice), slice_type can be 0 and 1.

[0074] In one embodiment, the value of slice_type may be determined from the value of pic_type_idc and num_slices_in_pic_minus1.

[0075] The bitstream matching requirement is that the value of num_slices_in_pic_minus1 is greater than or equal to 1 when the value of pic_type_idc indicates the presence of both intra-slices and inter-slices.

[0076] There are cases where the value of pic_type_idc indicates that both intra-slices and inter-slices exist in the encoded image, and the value of num_slices_in_pic_minus1 is greater than or equal to 1.

[0077] When all previously encoded slices are inter-slices, the last slice may be an intra-slice with slice_type equal to 2 (I-slice).

[0078] When all previously encoded slices are intra-slices, the last slice may be an inter-slice with a slice_type value ranging from 0 to 1, inclusive.

[0079] The methods proposed above may be implemented by a processing circuit (eg, one or more processors or one or more integrated circuits). In one example, one or more processors execute a program that is stored on a computer-readable medium to implement one or more of the proposed methods.

[0080] The above methods may be implemented in computer software using computer-readable instructions and physically stored on one or more computer-readable media. For example, in FIG. 3 shows a computer system 300 suitable for implementing some embodiments of the disclosed invention.

[0081] Computer software may be coded using any suitable machine code or computer language that may be assembled, compiled, linked, or similarly processed to create code containing instructions that can be executed directly, or through interpretation, execution of microcode, etc. .p., computer central processing units (CPU, central processing units), graphic processors (GPU, Graphics Processing Units), etc.

[0082] Instructions may be executed on various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, IoT devices, and the like.

[0083] The components of computer system 300 shown in FIG. 3 are illustrative in nature and are not intended to impose any limitation on the scope of application or functionality of computer software implementing embodiments of the present invention. The component configuration should also not be interpreted as having any dependency or requirement in conjunction with any one or combination of components shown in the exemplary embodiment of computer system 300.

[0084] Computer system 300 may include some human interface input devices. Such an input device may be responsible for input by one or more users through, for example, tactile input (e.g., keystrokes, waving, glove movements), audio input (e.g., voice, claps), visual input (e.g., gestures), olfactory input (not shown). Interface devices may also be used to capture certain media not necessarily directly related to conscious human input, such as sound (e.g. speech, music, external sound), images (e.g. scanned images, photographic images received from a still camera), video (eg, 2D video, 3D video including stereoscopic video).

[0085] Human interface input devices may include one or more of (one of each depicted): keyboard 301, mouse 302, touch pad 303, touch screen 310 and associated graphics adapter 350, data glove, joystick 305, microphone 306, scanner 307, camera 308.

[0086] Computer system 300 may also include some human interface output devices. Such output devices may stimulate the senses of one or more users through, for example, tactile output, sound, light, and smell/taste. Such output devices may include tactile output devices (e.g., tactile feedback via touch screen 310, data glove, or joystick 305, but may also be tactile feedback devices that do not serve as input devices), audio output devices (e.g.: speakers 309, headphones (not shown)), visual output devices (for example, screens (2910), including kinescope (CRT, cathode ray tube) screens, liquid-crystal (LCD, liquid-crystal display) screens, plasma screens, organic LED ( OLED, organic light-emitting diode) screens, each with or without touch screen input capabilities, each with or without tactile feedback capabilities, some of which are capable of two-dimensional visual output or more than three-dimensional output through, for example, stereographic output; virtual reality goggles (not shown), holographic displays and smoke tanks (not shown). ny)) and printers (not shown).

[0087] The computer system 300 may also include human accessible storage devices and associated media, such as optical media including CD/DVD ROM/RW 320 with CD/DVD media 321, and the like, cards 322 flash memory, removable hard drive or 323 solid state drive, traditional magnetic media such as tape and floppy disk (not shown), dedicated ROM/ASIC/PLD based devices such as security dongles (not shown), etc. P.

[0088] Those skilled in the art should also understand that the term "computer readable media" as used in conjunction with the invention disclosed herein does not encompass transmission media, carrier waves, or other short-term signals.

[0089] Computer system 300 may also include an interface to one or more communication networks. Networks can be, for example, wireless, wired, optical. Networks may additionally be local, wide area, metropolitan, transport and industrial, real-time, latency, etc. Examples of networks include local area networks such as Ethernet, wireless LANs, cellular networks, including global system for mobile communications (GSM), third generation (3G), fourth generation (4G), fifth generation ( 5G), long-term development of communication systems (LTE, Long-Term Evolution), global digital networks of wired or wireless television, including cable television, satellite television and terrestrial television, transport and industrial include CANFJus, etc. Some networks typically require external network interface adapters that are connected to some general purpose data ports or peripheral buses 349 (eg, the universal serial bus ports of the computer system 300); others are typically built into the core of computer system 300 by connecting to a system bus as described below (eg, an Ethernet interface to a PC computer system or a cellular network interface to a smartphone computer system). By way of example, network 355 may be connected to peripheral bus 349 using network interface 354. Using any of these networks, computer system 300 may communicate with other entities. Such communications may be unidirectional with receive-only capability (eg broadcast), unidirectional with transmit-only capability (eg CANbus to some CANbus devices), or bidirectional, eg to other computer systems using a local area network or a wide area digital network. Several protocols and protocol stacks may be used on each of these networks and the network interfaces described above (354).

[0090] The aforementioned human interface devices, human accessible storage devices, and network interfaces can be connected to the core 340 of the computer system 300.

[0091] The core 340 may include one or more central processing units (CPUs) 341, graphics processing units (GPUs) 342, field programmable gate arrays (FPGAs) 343, hardware accelerators 344 for some tasks, graphics adapter (350), etc. These devices, together with read-only memory (ROM) 345, RAM 346, high-capacity internal storage such as user-inaccessible internal hard drives 347, solid-state drives (SSDs, solid-state drives), etc., can be connected via system bus 348. In some computer systems, system bus 348 may be available in the form of one or more physical connectors to allow for expansions with additional CPUs, GPUs, and the like. Peripherals may connect either directly to the core system bus 348 or via a peripheral bus 349. Peripheral bus architectures include peripheral component interconnect (PCI), USB, and the like.

[0092] CPU 341, GPU 342, FPGA 343, and accelerators 344 may execute some instructions that together may constitute the above computer code. This computer code may be stored in ROM 345 or RAM 346. Transient data may also be stored in RAM 346, while persistent data may be stored in, for example, internal high capacity data storage 347. Fast storage and retrieval from any storage device can be achieved through the use of cache memory, which can be closely associated with one or more CPU 341, GPU 342, mass storage 347, ROM 345, RAM 346, and the like.

[0093] Computer-readable media may store computer code for performing various computer-implemented operations. The media and computer code may be specially created for the purposes of the present invention or may be well known and available to those skilled in the art of computer software.

[0094] By way of example, and not limitation, a computer system having architecture 300, and in particular core 340, may provide functional

capabilities due to the execution by the processor(s) (including(and) CPU, GPU, FPGA, accelerators, etc.) software embodied in one or more tangible computer-readable media. Such computer-readable media can be media associated with the user-accessible bulk data store described above, as well as some permanent storage of the core 340, such as internal bulk data storage 347 or ROM 345. implementation of the present invention may be stored in such devices and executed by the core 340. Computer-readable media may include one or more memory devices or chips, in accordance with specific needs. The software may direct the core 340, and in particular its processors (including CPUs, GPUs, FPGAs, and the like), to execute specific processes or specific portions of the specific processes described herein, including defining data structures stored in RAM 346 and modifying such data structures according to the processes defined by the software. Additionally or alternatively, the computer system may provide functionality through logic hardwired or otherwise embodied in circuitry (e.g., accelerator 344) that may operate instead of or in conjunction with software to perform specific processes or specific portions of the specific processes described herein. A reference to software may cover logic, and vice versa when appropriate. Reference to computer-readable media may encompass a circuit (eg, an integrated circuit (IC)) where software is stored for execution, a circuit embodying logic for execution, or both, as appropriate. The present invention encompasses any suitable combination of hardware and software.

[0095] While several exemplary embodiments are described herein, variations, permutations, and various replacement equivalents are possible and are within the scope of the invention. Thus, those skilled in the art can provide numerous systems and methods that, although not explicitly shown or described herein, embody the principles of the invention and thus fall within its spirit and scope.

[0096] Non-patent source:

[1] IDF 10092019_high level syntax control for video coding_v2

[0097] List of abbreviations:

HLS: high level syntax

HEVC: High Performance Video Coding

VVC: Universal Video Coding

CTU: coding tree unit

SPS: Sequence Parameter Set

PPS: Image Parameter Set

APS: adaptive parameter set

PH: image title

SH: slice header

SAO: Sample Adaptive Offset

AU: access block

NAL: Network Abstraction Layer

RBSP: Raw Byte Sequence Payload.

Claims (16)

1. A method for decoding video data, the method being carried out by at least one processor and comprising the steps of: indicate, by means of a picture header syntax element, for all slices included in the corresponding encoded picture, whether the slices are slices of type B, P, and/or I, the syntax element being encoded using an unsigned integer, and decoding the video data based on the slice types indicated by the syntax element. 2. The method of claim 1, wherein only related syntax elements are encoded for the encoded image. 3. The method of claim 2, wherein when all slices of the encoded image are indicated to include intra prediction, no inter prediction syntax element is encoded. 4. The method according to any one of paragraphs. 1-3, in which the syntax elements associated with the image header are included in the payload network abstraction layer block of the original slice-level byte sequence, and the flag is used to indicate the presence of the syntax elements associated with the image header in the payload network abstraction layer block of the original slice level byte sequence. 5. The method according to any one of paragraphs. 1-3, in which slice types can be determined from the decoded access block delimiter value. 6. The method according to any one of paragraphs. 1-3, in which slice types can be defined when signaled in high-level syntax. 7. The method according to any one of paragraphs. 1-3, in which slice types can be determined based on the number of rectangular slices in the encoded picture. 8. The method according to any one of paragraphs. 1-3, in which the syntax element is a syntax element encoded with a 0th order exponential Golomb code. 9. The method according to any one of paragraphs. 1-3, in which the syntax element is a 2-bit syntax element configurable with three states. 10. The method according to any one of paragraphs. 1-3, in which the syntax element is a 2-bit syntax element configurable with four states. 11. A device for decoding video data, comprising: at least one memory configured to store computer program code; and at least one processor configured to access at least one memory and operate according to a computer program code to implement the method according to any one of paragraphs. 1-10. 12. A computer-readable storage medium that stores instructions that cause at least one processor to carry out the method according to any one of paragraphs. 1-10.

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