Signalling of rendering information in neural network (NN)-based image bitstreams

Abstract

A mechanism for processing video data is disclosed. The mechanism includes determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream. A conversion is performed between a visual media data and the JPEG AI codestream based on the rendering information syntax structure.

Description

Signalling Of Rendering Information In Neural Network (NN)-based Image Bitstreams CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority to and benefits of U.S. Provisional Patent Application No. 63 / 558,508, filed on February 27, 2024 and U.S. Provisional Patent Application No.63 / 564,599, filed on March 13, 2024. All the aforementioned patent applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD

[0002] This patent document relates to generation, storage, and consumption of digital audio video media information in a file format. BACKGROUND

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

[0004] A first aspect relates to a method for processing video data comprising: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and performing a conversion between a visual media data and the JPEG AI codestream based on the rendering information syntax structure.

[0005] A second aspect relates to an apparatus for processing video data comprising: a processor; and a non- transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to perform any of the preceding aspects.

[0006] A third aspect relates to non-transitory computer readable medium comprising a computer program product for use by a video coding device, the computer program product comprising computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method of any of the preceding aspects.

[0007] A fourth aspect relates to a non-transitory computer-readable recording medium storing a JPEG AI codestream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and generating the JPEG AI codestream based on the determining.

[0008] A fifth aspect relates to a method for storing bitstream of a video comprising: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; generating a JPEG AI codestream based on the determining; and storing the JPEG AI codestream in a non-transitory computer-readable recording medium.

[0009] For the purpose of clarity, any one of the foregoing embodiments may be combined with any one or more of the other foregoing embodiments to create a new embodiment within the scope of the present disclosure.

[0010] These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.

[0012] FIG.1 is a block diagram showing an example video processing system.

[0013] FIG.2 is a block diagram of an example video processing apparatus.

[0014] FIG.3 is a flowchart for an example method of video processing.

[0015] FIG.4 is a block diagram that illustrates an example video coding system.

[0016] FIG.5 is a block diagram that illustrates an example encoder.

[0017] FIG.6 is a block diagram that illustrates an example decoder.

[0018] FIG.7 is a schematic diagram of an example encoder.

[0019] FIG.8 is a flowchart for an example method of video processing. DETAILED DESCRIPTION

[0020] It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and / or methods may be implemented using any number of techniques, whether currently known or yet to be developed. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. 1. Initial discussion

[0021] This document is related to neural network (NN)-based image and video coding. Specifically, this disclosure is related to signalling of rendering information in neural network (NN)-based image or video bitstreams, such as a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream, which may also be referred to as bitstream. The ideas may be applied individually or in various combinations, for image and / or video coding methods and specifications. 2. Further discussion

[0022] Deep learning has developed rapidly in a variety of areas, especially in computer vision and image processing. Inspired from the great success of deep learning technology to computer vision areas, many researchers have shifted their attention from image / video compression techniques to neural image / video compression technologies. Neural network is designed with the interdisciplinary research of neuroscience and mathematics. It has shown strong capabilities in the context of non-linear transform and classification. Neural network-basedimage / video compression technology has gained significant progress. It is reported that an example neural network- based image compression algorithm achieves comparable rate distortion (R-D) performance with Versatile Video Coding (VVC), a video coding standard developed by Joint Video Experts Team (JVET) with experts from motion picture experts group (MPEG) and Video Coding Experts Group (VCEG). With the performance of neural image compression continually being improved, neural network-based video compression has become an actively developing research area. However, neural network-based video coding still remains in its infancy due to the inherent difficulty of the problem. 2.1 Image / video compression

[0023] Image / video compression (also referred to as image / video coding) usually refers to the computing technology that compresses image or video into binary code to facilitate storage and transmission. The binary codes may or may not support losslessly reconstructing the original image or video, termed lossless compression and lossy compression. Most of the efforts are devoted to lossy compression since lossless reconstruction is not necessary in most scenarios. Usually the performance of image or video compression algorithms is evaluated from two aspects, including compression ratio and reconstruction quality. Compression ratio is directly related to the number of binary codes, the less the better; while reconstruction quality is measured by comparing the reconstructed image or video with the original image or video, the higher the better.

[0024] Image / video compression techniques can be divided into two branches, including the classical video coding methods and the neural-network-based video compression methods. Classical video coding schemes adopt transform-based solutions, in which researchers have exploited statistical dependency in the latent variables (e.g., discrete cosine transform (DCT) or wavelet coefficients) by carefully hand-engineering entropy codes modeling the dependencies in the quantized regime. Neural network-based video compression is in two flavors, neural network-based coding tools and end-to-end neural network-based video compression. The former is embedded into classical video codecs as coding tools and only serves as part of the framework, while the latter is a separate framework developed based on neural networks without depending on classical video codecs.

[0025] A series of classical video coding standards have been developed to accommodate the increasing visual content. The international standardization organizations International Organization for Standardization (ISO) / International Electrotechnical Commission (IEC) has two expert groups namely Joint Photographic Experts Group (JPEG) and Moving Picture Experts Group (MPEG), and International Telecommunication Union (ITU) telecommunication standardization sector (ITU-T) also has its own Video Coding Experts Group (VCEG) which is for standardization of image or video coding technology. The influential video coding standards published by these organizations include JPEG, JPEG 2000, H.262, H.264 / Advanced Video Coding (AVC) and H.265 / High Efficiency Video Coding (HEVC). After H.265 / HEVC, the Joint Video Experts Team (JVET) formed by MPEG and VCEG began working on a video coding standard Versatile Video Coding (VVC). The first version of VVCwas released in July 2020. An average of 50% bitrate reduction is reported by VVC under the same visual quality compared with HEVC.

[0026] A number of researchers are working on neural network-based image coding used in neural network- based image / video compression. But the network architectures used in example designs are relatively shallow, and the performance is not satisfactory. Benefit from the abundance of data and the support of powerful computing resources, neural network-based methods are better exploited in a variety of applications. At present, neural network-based image / video compression has shown promising improvements, and confirmed its feasibility. Nevertheless, this technology is still far from mature and a lot of challenges should be addressed. 2.2. Neural networks

[0027] Neural networks, also known as artificial neural networks (ANN), are the computational models used in machine learning technology which are usually composed of multiple processing layers and each layer is composed of multiple simple but non-linear basic computational units. One benefit of such deep networks is believed to be the capacity for processing data with multiple levels of abstraction and converting data into different kinds of representations. Note that these representations are not manually designed; instead, the deep network including the processing layers is learned from massive data using a general machine learning procedure. Deep learning eliminates the necessity of handcrafted representations, and thus is regarded useful especially for processing natively unstructured data, such as acoustic and visual signal, whilst processing such data has been a longstanding difficulty in the artificial intelligence field. 2.3. Neural networks for image and video compression

[0028] Example neural networks for image compression methods can be classified in two categories, including pixel probability modeling and auto-encoder. The former one belongs to the predictive coding strategy, while the latter one is the transform-based solution. Sometimes, these two methods are combined together.

[0029] Similar to classical video coding technologies, neural image compression serves as the foundation of intra compression in neural network-based video compression, thus development of neural network-based video compression technology comes later than neural network-based image compression, but needs far more efforts to solve the challenges due to its complexity. A few researchers are working on neural network-based video compression schemes. Compared with image compression, video compression needs efficient methods to remove inter-picture redundancy. Inter-picture prediction is then a key step in these works. Motion estimation and compensation is used, but is not implemented by trained neural networks until recently.

[0030] Studies on neural network-based video compression can be divided into two categories according to the targeted scenarios including random access and the low-latency. In random access case, the decoding can be started from any point of the sequence, the entire sequence is divided into multiple individual segments, and each segment can be decoded independently. The low-latency case aims to reduce decoding time, and thereby temporally previous frames can be used as reference frames to decode subsequent frames.2.4. The JPEG AI image coding standard and signalling of rendering information

[0031] The JPEG AI image coding standard is an image coding standard governed by the JPEG Working Group (WG), which is WG 1 of ISO / IEC Joint Technical Committee (JTC) 1 SC 29. The ISO / IEC number for the JPEG AI standard is ISO / IEC 6048.

[0032] An example JPEG AI draft specification utilizes some NN-based image coding methods described as mentioned above. Some of the features in the example JPEG AI specification, as well as a method for signalling of rendering information, are described or summarized below. Rendering information includes the coding- independent code points (CICP) rendering information, the mastering display color volume information, the content light level information, and dynamic metadata. 2.4.1. (6.2) Code stream layout ...

[0033] The code stream is composed of seven parts with byte boundary, which are: 1. Start Of Codestream (SOC) marker; 2. Picture Header marker (PIH) followed by picture header; 3. Tools Header marker (TOH) followed by tools information; 4. Rendering Information Header marker (RIH) followed by rendering information; 5. start of Quality map marker (SOQ) followed by code stream 6. Start of Z-stream marker (SOZ) followed codestream of hyper tensor z, including ^̂^^and ^̂^^^7. Start of Residual stream for primary component marker (SORp) followed by codestream of primary component residual, which includes ^̂^^; 8. Start of Residual stream for secondary component marker (SORs) followed by codestream of secondary component residual, which includes ^̂^^^; 9. End Of Codestream (EOC) marker.

[0034] The overall syntax structure of an image is:picture() { Descriptor SOC u(16) [s: Code assignment Symbol Description Mandatory / Optional ff t t f d t M dt...2.4.2. (6.3) Picture header

[0036] This sub-stream contains information about image height ^^, width ^^, latent space tiles location and sizes, control flags for each tool, scaling factors for primary and secondary component, ^^^^^^^^^^^^^^^^ – learnable model index and displacement for rate control parameters (^^^for primary and ^^^^for secondary component). 2.4.2.1 (9.3.1) Syntax tablepicture_header( ) { Descriptor PIH u(16) ... 2.4.2.3. (6.3.2) Picture header semantics

[0037] Following service information is signalled: picture_header_size is the number of bytes in the picture header excluding the first two-byte marker; img_width plus 64 specifies width of an input picture (from 64 to 65599); img_height plus 64 specifies height of the input picture (from 64 to 65599); ... 2.4.3 (6.5) Rendering information header

[0038] This optional sub-stream contains information about rendering information.Rendering information header syntax table rendering_information_header ( ) { Descriptor RIH u(16) C_ _ _ r colour primaries u(8)_ _ _ r f ( i=0i 3i++ ) { Ccontent_light_level_information() { Descriptor Ddynamic_metadata{ DescriptorpayloadSize = 0 while( next_bits( 8 ) = = 0xFF ) { R

[0039] colour_primaries carries a ColourPrimaries value as defined in ISO / IEC 23091-2. The default value shall be 1, which is the same colour primaries as defined in ITU-R BT.709.

[0040] transfer_characteristics carries a TransferCharacteristics value as defined in ISO / IEC 23091-2. The default value shall be 13. If matrix_coefficients is equal to 0, The transfer characteristics of value 13 is the same transfer characteristics as defined in IEC 61966-2-1 standard for red, green, and blue (sRGB).

[0041] matrix_coefficients carries a MatrixCoefficients value as defined in ISO / IEC 23091-2. The default value shall be 1, which is the same matrix coefficients as defined in ITU-R BT.709.

[0042] image_full_range_flag carries a VideoFullRangeFlag as defined in ISO / IEC 23091-2. The default value shall be 1, which means the image utilises full range.

[0043] chroma420_sample_loc_type carries a Chroma420SampleLocType as defined in ISO / IEC 23091- 2. The default value shall be 2, which means the the chroma samples and the luma samples are co-sited, without horizontal or vertical offsets.

[0044] mastering_display_colour_primaries_x[i] when in the range of 5 to 37000, inclusive, specifies the normalised x chromaticity coordinate of the colour primary component i of the mastering display, according to the International Commission on Illumination (CIE) 1931 definition of x as specified in ISO 11664-1, in increments of 0.00002.

[0045] mastering_display_colour_primaries_y[i] when in the range of 5 to 42000, inclusive, specifies the normalised x chromaticity coordinate of the colour primary component i of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in increments of 0.00002.

[0046] mastering_display_white_point_chromaticity_x when in the range of 5 to 37 000, inclusive, specifies the normalised x chromaticity coordinate of the white point of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in normalised increments of 0.00002.

[0047] mastering_display_white_point_chromaticity_y when in the range of 5 to 42 000, inclusive, specifies the normalised x chromaticity coordinate of the white point of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in normalised increments of 0.00002.

[0048] mastering_display_maximum_luminance when in the range of 50000 to 100000000, specifies the nominal maximum display luminance of the mastering display in units of 0.0001 candelas per square metre.

[0049] mastering_display_minimum_luminance when in the range of 1 to 50000, specifies the nominal minimum display luminance of the mastering display in units of 0.0001 candelas per square metre. When mastering_display_maximum_luminance is equal to 50000, mastering_display_minimum_luminance shall not be equal to 50000..

[0050] maximum_content_light_level, when not equal to 0, indicates an upper bound on the maximum light level among all individual samples in a 4:4:4 representation of red, green, and blue colour primary intensities (in the linear light domain) for the pictures, in units of candelas per square metre.

[0051] maximum_frame_average_light_level, when not equal to 0, indicates an upper bound on the maximum average light level among the samples in a 4:4:4 representation of red, green, and blue colour primary intensities (in the linear light domain) for any individual picture, in units of candelas per square metre.

[0052] last_payload_size_byte is the last byte of the payload size of dynamic metadata.

[0053] dynamic_metadata_payload_byte shall be a byte containing data registered as specified in Recommendation ITU-T T.35. ... 3. Technical problems solved by disclosed technical solutions

[0054] The example design on signalling of JPEG AI rendering information has the following problems:

[0055] First, the syntax and semantics for the rendering information header, including the rendering information header marker, is inconsistent, as the syntax is specified in a manner that the rendering information header, including the rendering information header marker, is not optional, while in the semantics says it is optional.

[0056] Second, four types of rendering information are involved, namely the coding-independent code points (CICP) rendering information, the mastering display color volume information, the content light level information, and dynamic metadata. However, it is not possible to signal some of these types of rendering information while not to signal the other types of rendering information.

[0057] Third, the number of bits in the syntax structure for the CICP rendering information is not an integer number of bytes.

[0058] Fourth, in the syntax for dynamic metadata signalling, there lacks an indication of the dynamic metadata type. For example, one type of dynamic metadata is referred to as ST 2094-10 data, which is specified inSociety of Motion Picture and Television Engineers (SMPTE) Standard Technology (ST) 2094-10, "Dynamic Metadata for Color Volume Transform – Application #1", as well as in some other standard specifications, e.g., ETSI TS 103572, High Dynamic Range (HDR) Signalling and Carriage of Dynamic Metadata for Colour Volume Transform; Application #1.

[0059] Fifth, the syntax for dynamic metadata signalling is not straightforward and the payload size signalling is inefficient when the size is greater than 256 bytes, and the larger the size the more inefficient. 4. A listing of solutions and embodiments

[0060] To solve the above-described problems, methods as summarized below are disclosed. The aspects should be considered as examples to explain the general concepts and should not be interpreted in a narrow way. Furthermore, these examples can be applied individually or combined in any manner. 1) In one example, in a JPEG AI codestream, the rendering information, including one or more of the coding-independent code points (CICP) rendering information, the mastering display color volume information, the content light level information, and dynamic metadata, is signalled in a rendering information syntax structure and the rendering information syntax structure is directly included in the picture header. a. In one example, additionally, no rendering information header marker syntax element is signalled in the rendering information syntax structure. 2) In one example, in a JPEG AI codestream, it is allowed to signal only some types of rendering information, e.g., one or more of but not all of the coding-independent code points (CICP) rendering information, the mastering display color volume information, the content light level information, and dynamic metadata, while not to signal the other types of rendering information. a. In one example, for a particular type of rendering information, an indication is included the JPEG AI codestream to indicate whether the particular type of rendering information is present. i. In one example, for each of the four types of rendering information, an indication is included the JPEG AI codestream to indicate whether the particular type of rendering information is present. 3) In one example, the syntax structure for the CICP rendering information includes an integer number of bytes. a. In one example, a 7-bit syntax element, e.g., named cicp_reserved_zero_7bits, is included in the syntax structure for the CICP rendering information immediately after the image_full_range_flag syntax element. i. In one example, alternatively, a 7-bit syntax element, e.g., named cicp_reserved_zero_7bits, is included in the syntax structure for the CICP rendering information immediately before the image_full_range_flag syntax element.) In one example, in a JPEG AI codestream, the dynamic metadata rendering information is signalled by a syntax structure that consists of an indication of the dynamic metadata type, an indication of the size of the dynamic metadata, and the data bytes of the dynamic metadata, preferably in the order listed. a. In one example, the dynamic metadata type is indicated by an 8-bit syntax element, e.g., named dm_type. i. In one example, it is specified that dm_type equal to a particular value, e.g., 0, specifies that the dynamic metadata is the ST2094-10_data() structure as specified in ETSI TS 103572 V1.3.1. ii. In one example, it is specified that some values of dm_type are reserved for future use. iii. In one example, it is specified that, the value of dm_type shall be equal to 0 for JPEG AI codestreams conforming to this version of this standard. iv. In one example, it is specified that, when encountering dm_type greater than 0, decoders conforming to this version of this standard shall ignore the dynamic_metadata() syntax structure.. b. In one example, the size of the dynamic metadata is indicated by a 16-bit syntax element. i. In one example, the size of the dynamic metadata is indicated by an 8-bit syntax element. ii. In one example, the length of the syntax element indication of the size of the dynamic metadata is indicated by another syntax element, e.g., a 1-bit or a 2-bit syntax element.) In one example, in a JPEG AI codestream, the rendering information, including one or more of the coding-independent code points (CICP) rendering information, the mastering display color volume information, the content light level information, and dynamic metadata, is signalled in a rendering information syntax structure and the rendering information syntax structure is directly included in the picture() syntax structure, wherein the presence of the rendering information syntax structure is conditioned based on whether the value of the next M-bits immediately following another syntax structure directly present in the picture() syntax structure is equal to the value of the render information marker. a. In one example, M is equal to 16, and the value of the render information marker is equal to 0xff84. ) In one example, based on item 1 or 5 above, within the rendering information syntax structure, there is an N-bit syntax element SE_1 indicating the length, in bytes, of another syntax element SE_2, a number of presence flags indicating the presence of the different types of rendering information, a number of reserved bits, and the syntax element SE_2, wherein the syntax element SE_2 indicates the size, in bytes, of all remaining data after the last of SE_1, the presence flag, the reserved bits, and SE_2 in the rendering information syntax structure.a. In one example, the sum of N, the number of presence flags, and the number of reserved bits is an integer multiple of 8. b. In one example, the sum of N, the number of presence flags, and the number of reserved bits is equal to 8. c. In one example, N is 2, the number of presence flags is 4, and the number of reserved bits is 2, and the values of 0, 1, 2, and 3 of SE_1 indicates the lengths of SE_2 being 1, 2, 3, and 4 bytes, respectively. 7) In one example, based on item 1 or 5 above, within the rendering information syntax structure, there is an X-bit syntax element SE_1 indicating the size, in bytes, of all remaining data after the last of SE_1 and a number of presence flags indicating the presence of the CICP rendering information, the mastering display color volume information, the content light level information, and dynamic metadata, wherein the sum of X and the number of the presence flags (e.g., 4) is an integer multiple of 8. a. In one example, X is equal to 24. 8) In one example, based on item 1 or 5 above, the CICP rendering information is included in a CICP rendering information syntax structure, and within the CICP rendering information syntax structure, the syntax element that carries a Chroma420SampleLocType as defined in ISO / IEC 23091-2 is u(3)-coded using 3 bits. a. In one example, alternatively, the syntax element that carries a Chroma420SampleLocType as defined in ISO / IEC 23091-2 is u(4)-coded using 4 bits. 9) In one example, based on item 1 or 5 above, the CICP rendering information is included in a CICP rendering information syntax structure, and within the CICP rendering information syntax structure there is a syntax element SE_3 that carries a Chroma420SampleLocType as defined in ISO / IEC 23091- 2, wherein it is specified that, when the chroma format is not 4:2:0, the semantics of SE_3 is unspecified and the decoder shall ignore the value of SE_3. a. In one example, alternatively, the syntax element SE_3 is conditionally signalled and it is present in the CICP rendering information syntax structure only when the chroma format is 4:2:0. 10) In one example, based on item 8 or 9 above, zero or more byte-alignment bits are appended at the end of the CICP rendering information syntax structure until the total number of bits in the CICP rendering information syntax structure is an integer multiple of 8. 11) In one example, based on item 1 or 5 above, zero or more byte-alignment bits are appended at the end of the rendering information syntax structure until the total number of bits in the rendering information syntax structure is an integer multiple of 8. 5. Embodiments

[0061] Below are some example embodiments for the aspects summarized above in Section 4.5.1 First Embodiment

[0062] This embodiment is for all items items 1, 1.a, 2, 2.a, 2.a.i, 3, 3.a, 4, 4.a, 4.a.i, 4.a.ii, 4.a.iii, 4.a.iv, and 4.b summarized above in Section 4. 5.1.1. (6.2) Code stream layout

[0063] ...

[0064] The code stream is composed of six parts with byte boundary, which are: 1. Start Of Codestream marker (SOC); 2. Picture Header marker (PIH) followed by picture header; 3. Tools Header marker (TOH) followed by tools information; 4. start of Quality map marker (SOQ) followed by code stream 5. Start of Z-stream marker (SOZ) followed codestream of hyper tensor z, including ^̂^^and ^̂^^^6. Start of Residual stream for primary component marker (SORp) followed by codestream of primary component residual, which includes ^̂^^; 7. Start of Residual stream for secondary component marker (SORs) followed by codestream of secondary component residual, which includes ^̂^^^; 8. End Of Codestream marker (EOC).

[0065] The overall syntax structure of an image is: picture() { Descriptor SOC (16)

[0066] Each codestream starts with a 16-bit marker. All markers used in this specification are as follows: Code assignment Symbol Description Mandatory / Optional0xff84 xxx Reserved Optional 0xff85 xxx Reserved Optional 5.1

[0067] This sub-stream contains information about image height ^^, width ^^, latent space tiles location and sizes, control flags for each tool, scaling factors for primary and secondary component, ^^^^^^^^^^^^^^^^ – learnable model index and displacement for rate control parameters (^^^for primary and ^^^^for secondary component). 2.4.2.1 (9.3.1) Syntax table picture_header( ) { Descriptormodel_id u(2) model_header(0) ..2.4.2.3 (6.3.2) Picture header semantics

[0068] Following service information is signalled: picture_header_size is the number of bytes in the picture header excluding the first two-byte marker; img_width plus 64 specifies width of an input picture (from 64 to 65599); img_height plus 64 specifies height of the input picture (from 64 to 65599); ... 5.1.3 (6.5) Rendering information Rendering information syntax rendering_info( ) { Descriptor cic info resent fla u(1) Ccicp_rendering_info() { Descriptormatrix_coefficients u(8) image_full_range_flag u(1)r for ( i=0;i<3;i++ ) { C_ _ _ r i t tlihtl l (16) Dynamc_meaaa() { escrporRendering information semantics

[0069] cicp_info_present_flag equal to 1 specifies that the cicp_rendering_info() syntax structure is present. cicp_info_present_flag equal to 0 specifies that the cicp_rendering_info() syntax structure is not present.

[0070] mdcv_info_present_flag equal to 1 specifies that the mastering_display_color_volume() syntax structure is present. mdcv_info_present_flag equal to 0 specifies that the mastering_display_color_volume() syntax structure is not present.

[0071] cll_info_present_flag equal to 1 specifies that the content_light_level_info() syntax structure is present. cll_info_present_flag equal to 0 specifies that the content_light_level_info() syntax structure is not present.

[0072] dm_present_flag equal to 1 specifies that the dynamic_metadata() syntax structure is present. dm_present_flag equal to 0 specifies that the dynamic_metadata() syntax structure is not present.

[0073] ri_reserved_zero_4bits shall be equal to 0 in a JPEG codestream conforming to this version of this standard. Values greater than 0 for ri_reserved_zero_4bits are reserved for future use by ISO / IEC. When encountering ri_reserved_zero_4bits greater than 0, decoders conforming to this version of this standard shall ignore the ri_reserved_zero_4bits syntax element.

[0074] colour_primaries carries a ColourPrimaries value as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for colour_primaries is inferred to be equal to 1, which is the same colour primaries as defined in ITU recommendation broadcast televsion services 709 (ITU-R BT.709).

[0075] transfer_characteristics carries a TransferCharacteristics value as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for transfer_characteristics is inferred to be equal to 13. When matrix_coefficients is equal to 0, the transfer characteristics of value 13 is the same transfer characteristics as defined in IEC 61966-2-1 sRGB.

[0076] matrix_coefficients carries a MatrixCoefficients value as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for matrix_coefficients is inferred to be equal to 1, which is the same matrix coefficients as defined in ITU-R BT.709.

[0077] image_full_range_flag carries a VideoFullRangeFlag as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for image_full_range_flag is inferred to be equal to 1, which means the image utilises full range.

[0078] cicp_reserved_zero_7bits shall be equal to 0 in a JPEG codestream conforming to this version of this standard. Values greater than 0 for cicp_reserved_zero_7bits are reserved for future use by ISO / IEC. When encountering cicp_reserved_zero_7bits greater than 0, decoders conforming to this version of this standard shall ignore the cicp_reserved_zero_7bits syntax element.

[0079] chroma420_sample_loc_type carries a Chroma420SampleLocType as defined in ISO / IEC 23091- 2. When cicp_info_present_flag is equal to 0, the default value for chroma420_sample_loc_type is inferred to be equal to 2, which means that the chroma samples and the luma samples are co-sited, without horizontal or vertical offsets.

[0080] mastering_display_colour_primaries_x[i], when in the range of 5 to 37000, inclusive, specifies the normalised x chromaticity coordinate of the colour primary component i of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in increments of 0.00002.

[0081] mastering_display_colour_primaries_y[i], when in the range of 5 to 42000, inclusive, specifies the normalised x chromaticity coordinate of the colour primary component i of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in increments of 0.00002.

[0082] mastering_display_white_point_chromaticity_x, when in the range of 5 to 37 000, inclusive, specifies the normalised x chromaticity coordinate of the white point of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in normalised increments of 0.00002.

[0083] mastering_display_white_point_chromaticity_y, when in the range of 5 to 42 000, inclusive, specifies the normalised x chromaticity coordinate of the white point of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in normalised increments of 0.00002.

[0084] mastering_display_maximum_luminance, when in the range of 50000 to 100000000, specifies the nominal maximum display luminance of the mastering display in units of 0.0001 candelas per square metre.

[0085] mastering_display_minimum_luminance, when in the range of 1 to 50000, specifies the nominal minimum display luminance of the mastering display in units of 0.0001 candelas per square metre. When mastering_display_maximum_luminance is equal to 50000, mastering_display_minimum_luminance shall not be equal to 50000.

[0086] maximum_content_light_level, when not equal to 0, indicates an upper bound on the maximum light level among all individual samples in a 4:4:4 representation of red, green, and blue colour primary intensities (in the linear light domain) for the pictures, in units of candelas per square metre.

[0087] maximum_frame_average_light_level, when not equal to 0, indicates an upper bound on the maximum average light level among the samples in a 4:4:4 representation of red, green, and blue colour primary intensities (in the linear light domain) for any individual picture, in units of candelas per square metre.

[0088] dm_type specifies the type of the dynamic metadata. dm_type equal to 0 specifies that the dynamic metadata carried by dm_data_byte[i] for i in the range of 0 to dm_size − 1, inclusive, is the ST2094-10_data() structure as specified in European Telecommunications Standards Institute (ETSI) Technical Specification (TS) 103572 V1.3.1. The value of dm_type shall be equal to 0 for JPEG AI codestreams conforming to this version of this standard. Values greater than 0 for dm_type are reserved for future use by ISO / IEC. When encountering dm_type greater than 0, decoders conforming to this version of this standard shall ignore the dynamic_metadata() syntax structure.

[0089] dm_size specifies the number of bytes of the dynamic metadata.

[0090] dm_data_byte[i] is the i-th byte of the dynamic metadata. 5.2 Second Embodiment

[0091] This embodiment is for all items items items 5, 5.a, 6, 6.a, 6.b, 6.c, 8, and 9 summarized above in Section 4. 5.2.1. (2.2) Specification of syntax functions and descriptors

[0092] The functions presented here are used in the syntactical description. These functions are expressed in terms of the value of a bitstream pointer that indicates the position of the next bit to be read by the decoding process from the bitstream.

[0093] read_bits( n ) reads the next n bits from the bitstream and advances the bitstream pointer by n bit positions. When n is equal to 0, read_bits( n ) is specified to return a value equal to 0 and to not advance the bitstream pointer.

[0094] read_bits_from_back( n ) reads the n bits from the end of a sub-stream in bitstream and move back the sub-stream bitstream pointer by n bit positions. When n is equal to 0, read_bits_from_back( n ) is specified to return a value equal to 0 and to not move the sub-stream bitstream pointer.

[0095] next_bits( n ) provides the next bits in the bitstream for comparison purposes, without advancing the bitstream pointer.

[0096] The following descriptors specify the parsing process of each syntax element: – b(8): byte having any pattern of bit string (8 bits). The parsing process for this descriptor is specified by the return value of the function read_bits( 8 ). – f(n): fixed-pattern bit string using n bits written (from left to right) with the left bit first. The parsing process for this descriptor is specified by the return value of the function read_bits( n ). – i(n): signed integer using n bits. When n is "v" in the syntax table, the number of bits varies in a manner dependent on the value of other syntax elements. The parsing process for this descriptor is specified by the return value of the function read_bits( n ) interpreted as a two's complement integer representation with most significant bit written first. – se(v): signed integer 0-th order Exp-Golomb-coded syntax element with the left bit first. The parsing process for this descriptor is specified in clause Annex C with the order k equal to 0. – u(n): unsigned integer using n bits. When n is "v" in the syntax table, the number of bits varies in a manner dependent on the value of other syntax elements. The parsing process for this descriptor is specified by the return value of the function read_bits( n ) interpreted as a binary representation of an unsigned integer with most significant bit written first. – ub(n): unsigned integer using n bits. When n is "v" in the syntax table, the number of bits varies in a manner dependent on the value of other syntax elements. The parsing process for this descriptor is specified by the return value of the function read_bits_from_back( n ) interpreted as a binary representation of an unsigned integer with most significant bit written first. 5.2.2. (6.2) Code stream layout ...

[0097] The code stream is composed of seven parts with byte boundary, which are: 1. SOC - Start Of Codestream marker; 2. PIH (Picture Header marker) followed by picture header; 3. TOH (Tools Header marker) followed by tools information; 4. RDI (Rendering Information marker) followed by rendering information;5. SOQ (start of Quality map marker) followed by code stream 6. SOZ (Start of Z-stream marker) followed codestream of hyper tensor z, including ^̂^^and ^̂^^^7. SORp (Start of Residual stream for primary component marker) followed by codestream of primary component residual, which includes ^̂^^; 8. SORs (Start of Residual stream for secondary component marker) followed by codestream of secondary component residual, which includes ^̂^^^; 9. EOC - End Of Codestream marker.

[0098] The overall syntax structure of an image is: picture() { Descriptor SOC u(16)

[0099] Each codestream starts with a 16-bit marker. All markers used in this specification are as follows: Code assignment Symbol Description Mandatory / Optional0xff89 SORp Start of residual (primary component) Mandatory 0xff8a SORs Start of residual (secondary Mandatory [0o 0xff84, inclusive, is also present, the sub-stream associated with the second marker shall precede, in decoder order, the quality map sub-stream, which is associated with the SOQ marker. 5.2.3. (6.3) Picture header

[0101] This sub-stream contains information about image height ^^, width ^^, latent space tiles location and sizes, control flags for each tool, scaling factors for primary and secondary component, ^^^^^^^^^^^^^^^^ – learnable model index and displacement for rate control parameters (^^^for primary and ^^^^for secondary component).2.4.2.1 (9.3.1) Syntax table picture_header( ) { Descriptor PIH u(16) ... 2.4.2.3 (6.3.2) Picture header semantics

[0102] Following service information is signalled:

[0103] picture_header_size is the number of bytes in the picture header excluding the first two-byte marker;

[0104] img_width plus 64 specifies width of an input picture (from 64 to 65599);

[0105] img_height plus 64 specifies height of the input picture (from 64 to 65599); ... 5.2.4. (6.5) Rendering information Rendering information syntax rendering_information( ) { Descriptorcll_info_present_flag u(1) dm_present_flag u(1) C_ _ r colour rimaries u(8)Mastering display color volume mastering_display_color_volume() { Descriptor for ( i=0;i<3;i++ ) { C_ _ _ r maximum content light level u(16) D_ d t (8) Render ng n ormaton semantcs

[0106] ri_payload_size_len_in_bytes_minus1 plus 1 specifies the number of bytes used to represent the ri_payload_size_val syntax element.

[0107] cicp_info_present_flag equal to 1 specifies that the cicp_rendering_info() syntax structure is present. cicp_info_present_flag equal to 0 specifies that the cicp_rendering_info() syntax structure is not present.

[0108] mdcv_info_present_flag equal to 1 specifies that the mastering_display_color_volume() syntax structure is present. mdcv_info_present_flag equal to 0 specifies that the mastering_display_color_volume() syntax structure is not present.

[0109] cll_info_present_flag equal to 1 specifies that the content_light_level_info() syntax structure is present. cll_info_present_flag equal to 0 specifies that the content_light_level_info() syntax structure is not present.

[0110] dm_present_flag equal to 1 specifies that the dynamic_metadata() syntax structure is present. dm_present_flag equal to 0 specifies that the dynamic_metadata() syntax structure is not present.

[0111] When the rendering_information() syntax structure is present in the picture() syntax structure, at least one of cicp_info_present_flag, mdcv_info_present_flag, cll_info_present_flag, and , dm_present_flag shall be equal to 1.

[0112] ri_reserved_zero_2bits shall be equal to 0 in a JPEG AI codestream conforming to this version of this standard. Values greater than 0 for ri_reserved_zero_2bits are reserved for future use by ISO / IEC. When encountering ri_reserved_zero_2bits greater than 0, decoders conforming to this version of this standard shall ignore the ri_reserved_zero_2bits syntax element.

[0113] ri_payload_size_val specifies the size, in bytes, of the rendering information sub-stream payload (i.e., the sub-stream excluding the syntax elements starting from the RDI marker up to and including ri_payload_size_val). The ri_payload_size_val syntax element is represented by ri_payload_size_len_in_bytes_minus1 + 1 bytes.

[0114] colour_primaries carries a ColourPrimaries value as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for colour_primaries is inferred to be equal to 1, which is the same colour primaries as defined in ITU-R BT.709.

[0115] transfer_characteristics carries a TransferCharacteristics value as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for transfer_characteristics is inferred to be equal to 13. When matrix_coefficients is equal to 0, the transfer characteristics of value 13 is the same transfer characteristics as defined in IEC 61966-2-1 sRGB.

[0116] matrix_coefficients carries a MatrixCoefficients value as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for matrix_coefficients is inferred to be equal to 1, which is the same matrix coefficients as defined in ITU-R BT.709.

[0117] image_full_range_flag carries a VideoFullRangeFlag as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for image_full_range_flag is inferred to be equal to 1, which means the image utilises full range.

[0118] chroma420_sample_loc_type, when the chroma format is not 4:2:0, carries a Chroma420SampleLocType as defined in ISO / IEC 23091-2. When cicp_info_present_flag is equal to 0, the default value for chroma420_sample_loc_type is inferred to be equal to 2, which means that the chroma samples and the luma samples are co-sited, without horizontal or vertical offsets. When the chroma format is not 4:2:0, the semantics of chroma420_sample_loc_type is unspecified and the decoder shall ignore the value of chroma420_sample_loc_type.

[0119] cicp_reserved_zero_4bits shall be equal to 0 in a JPEG AI codestream conforming to this version of this standard. Values greater than 0 for cicp_reserved_zero_4bits are reserved for future use by ISO / IEC. Whenencountering cicp_reserved_zero_4bits greater than 0, decoders conforming to this version of this standard shall ignore the cicp_reserved_zero_4bits syntax element.

[0120] mastering_display_colour_primaries_x[i], when in the range of 5 to 37000, inclusive, specifies the normalised x chromaticity coordinate of the colour primary component i of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in increments of 0.00002.

[0121] mastering_display_colour_primaries_y[i], when in the range of 5 to 42000, inclusive, specifies the normalised x chromaticity coordinate of the colour primary component i of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in increments of 0.00002.

[0122] mastering_display_white_point_chromaticity_x, when in the range of 5 to 37000, inclusive, specifies the normalised x chromaticity coordinate of the white point of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in normalised increments of 0.00002.

[0123] mastering_display_white_point_chromaticity_y, when in the range of 5 to 42000, inclusive, specifies the normalised x chromaticity coordinate of the white point of the mastering display, according to the CIE 1931 definition of x as specified in ISO 11664-1, in normalised increments of 0.00002.

[0124] mastering_display_maximum_luminance, when in the range of 50000 to 100000000, specifies the nominal maximum display luminance of the mastering display in units of 0.0001 candelas per square metre.

[0125] mastering_display_minimum_luminance, when in the range of 1 to 50000, specifies the nominal minimum display luminance of the mastering display in units of 0.0001 candelas per square metre. When mastering_display_maximum_luminance is equal to 50000, mastering_display_minimum_luminance shall not be equal to 50000.

[0126] maximum_content_light_level, when not equal to 0, indicates an upper bound on the maximum light level among all individual samples in a 4:4:4 representation of red, green, and blue colour primary intensities (in the linear light domain) for the pictures, in units of candelas per square metre.

[0127] maximum_frame_average_light_level, when not equal to 0, indicates an upper bound on the maximum average light level among the samples in a 4:4:4 representation of red, green, and blue colour primary intensities (in the linear light domain) for any individual picture, in units of candelas per square metre.

[0128] dm_type specifies the type of the dynamic metadata. dm_type equal to 0 specifies that the dynamic metadata carried by dm_data_byte[i] for i in the range of 0 to dm_size − 1, inclusive, is the ST2094-10_data() structure as specified in ETSI TS 103572 V1.3.1. The value of dm_type shall be equal to 0 for JPEG AI codestreams conforming to this version of this standard. Values greater than 0 for dm_type are reserved for future use by ISO / IEC. When encountering dm_type greater than 0, decoders conforming to this version of this standard shall ignore the dynamic_metadata() syntax structure.

[0129] dm_size specifies the number of bytes of the dynamic metadata.

[0130] dm_data_byte[i] is the i-th byte of the dynamic metadata.

[0131] FIG. 1 is a block diagram showing 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 the system 4000. The system 4000 may include input 4002 for receiving video content. The video content may be received in a raw or uncompressed format, e.g., 8 or 10 bit multi-component pixel values, or may be in a compressed or encoded format. The input 4002 may represent a network interface, a peripheral bus interface, or a storage interface. Examples of network interface include wired interfaces such as Ethernet, passive optical network (PON), etc. and wireless interfaces such as Wi-Fi or cellular interfaces.

[0132] The system 4000 may include a coding component 4004 that may implement the various coding or encoding methods described in the present document. The coding component 4004 may reduce the average bitrate of video from the input 4002 to the output of the coding component 4004 to produce a coded representation of the video. The coding techniques are therefore sometimes called video compression or video transcoding techniques. The output of the coding component 4004 may be either stored, or transmitted via a communication connected, as represented by the component 4006. The stored or communicated bitstream (or coded) representation of the video received at the input 4002 may be used by a component 4008 for generating pixel values or displayable video that is sent to a display interface 4010. The process of generating user-viewable video from the bitstream representation is sometimes called video decompression. Furthermore, while certain video processing operations are referred to as “coding” operations or tools, it will be appreciated that the coding tools or operations are used at an encoder and corresponding decoding tools or operations that reverse the results of the coding will be performed by a decoder.

[0133] Examples of a peripheral bus interface or a display interface may include universal serial bus (USB) or high definition multimedia interface (HDMI) or Displayport, and so on. Examples of storage interfaces include serial advanced technology attachment (SATA), peripheral component interconnect (PCI), integrated drive electronics (IDE) interface, and the like. The techniques described in the present document may be embodied in various electronic devices such as mobile phones, laptops, smartphones or other devices that are capable of performing digital data processing and / or video display.

[0134] FIG.2 is a block diagram of an example video processing apparatus 4100. The apparatus 4100 may be used to implement one or more of the methods described herein. The apparatus 4100 may be embodied in a smartphone, tablet, computer, Internet of Things (IoT) receiver, and so on. The apparatus 4100 may include one or more processors 4102, one or more memories 4104 and video processing circuitry 4106. The processor(s) 4102 may be configured to implement one or more methods described in the present document. The memory (memories) 4104 may be used for storing data and code used for implementing the methods and techniques described herein. The video processing circuitry 4106 may be used to implement, in hardware circuitry, some techniques described in the present document. In some embodiments, the video processing circuitry 4106 may be at least partly included in the processor 4102, e.g., a graphics co-processor.

[0135] FIG.3 is a flowchart for an example method 4200 of video processing. The method 4200 determines one or more of coding-independent code points (CICP) rendering information, mastering display color volumeinformation, content light level information, and dynamic metadata is contained in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream at step 4202. A conversion between a visual media data and the JPEG AI codestream is perfomed based on the rendering information syntax structure at step 4204. The conversion may include encoding at an encoder, decoding at a decoder, or combinations thereof.

[0136] It should be noted that the method 4200 can be implemented in an apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, such as video encoder 4400, video decoder 4500, and / or encoder 4600. In such a case, the instructions upon execution by the processor, cause the processor to perform the method 4200. Further, the method 4200 can be performed by a non-transitory computer readable medium comprising a computer program product for use by a video coding device. The computer program product comprises computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method 4200.

[0137] FIG.4 is a block diagram that illustrates an example video coding system 4300 that may utilize the techniques of this disclosure. The video coding system 4300 may include a source device 4310 and a destination device 4320. Source device 4310 generates encoded video data which may be referred to as a video encoding device. Destination device 4320 may decode the encoded video data generated by source device 4310 which may be referred to as a video decoding device.

[0138] Source device 4310 may include a video source 4312, a video encoder 4314, and an input / output (I / O) interface 4316. Video source 4312 may include a source such as a video capture device, an interface to receive video data from a video content provider, and / or a computer graphics system for generating video data, or a combination of such sources. The video data may comprise one or more pictures. Video encoder 4314 encodes the video data from video source 4312 to generate a bitstream. The bitstream may include a sequence of bits that form a coded representation of the video data. The bitstream may include coded pictures and associated data. The coded picture is a coded representation of a picture. The associated data may include sequence parameter sets, picture parameter sets, and other syntax structures. I / O interface 4316 may include a modulator / demodulator (modem) and / or a transmitter. The encoded video data may be transmitted directly to destination device 4320 via I / O interface 4316 through network 4330. The encoded video data may also be stored onto a storage medium / server 4340 for access by destination device 4320.

[0139] Destination device 4320 may include an I / O interface 4326, a video decoder 4324, and a display device 4322. I / O interface 4326 may include a receiver and / or a modem. I / O interface 4326 may acquire encoded video data from the source device 4310 or the storage medium / server 4340. Video decoder 4324 may decode the encoded video data. Display device 4322 may display the decoded video data to a user. Display device 4322 may be integrated with the destination device 4320, or may be external to destination device 4320, which can be configured to interface with an external display device.

[0140] Video encoder 4314 and video decoder 4324 may operate according to a video compression standard, such as the High Efficiency Video Coding (HEVC) standard, Versatile Video Coding (VVM) standard and other current and / or further standards.

[0141] FIG.5 is a block diagram illustrating an example of video encoder 4400, which may be video encoder 4314 in the system 4300 illustrated in FIG.4. Video encoder 4400 may be configured to perform any or all of the techniques of this disclosure. The video encoder 4400 includes a plurality of functional components. The techniques described in this disclosure may be shared among the various components of video encoder 4400. In some examples, a processor may be configured to perform any or all of the techniques described in this disclosure.

[0142] The functional components of video encoder 4400 may include a partition unit 4401, a prediction unit 4402 which may include a mode select unit 4403, a motion estimation unit 4404, a motion compensation unit 4405, an intra prediction unit 4406, a residual generation unit 4407, a transform processing unit 4408, a quantization unit 4409, an inverse quantization unit 4410, an inverse transform unit 4411, a reconstruction unit 4412, a buffer 4413, and an entropy encoding unit 4414.

[0143] In other examples, video encoder 4400 may include more, fewer, or different functional components. In an example, prediction unit 4402 may include an intra block copy (IBC) unit. The IBC unit may perform prediction in an IBC mode in which at least one reference picture is a picture where the current video block is located.

[0144] Furthermore, some components, such as motion estimation unit 4404 and motion compensation unit 4405 may be highly integrated, but are represented in the example of video encoder 4400 separately for purposes of explanation.

[0145] Partition unit 4401 may partition a picture into one or more video blocks. Video encoder 4400 and video decoder 4500 may support various video block sizes.

[0146] Mode select unit 4403 may select one of the coding modes, intra or inter, e.g., based on error results, and provide the resulting intra or inter coded block to a residual generation unit 4407 to generate residual block data and to a reconstruction unit 4412 to reconstruct the encoded block for use as a reference picture. In some examples, mode select unit 4403 may select a combination of intra and inter prediction (CIIP) mode in which the prediction is based on an inter prediction signal and an intra prediction signal. Mode select unit 4403 may also select a resolution for a motion vector (e.g., a sub-pixel or integer pixel precision) for the block in the case of inter prediction.

[0147] To perform inter prediction on a current video block, motion estimation unit 4404 may generate motion information for the current video block by comparing one or more reference frames from buffer 4413 to the current video block. Motion compensation unit 4405 may determine a predicted video block for the current video block based on the motion information and decoded samples of pictures from buffer 4413 other than the picture associated with the current video block.

[0148] Motion estimation unit 4404 and motion compensation unit 4405 may perform different operations for a current video block, for example, depending on whether the current video block is in an I slice, a P slice, or a B slice.

[0149] In some examples, motion estimation unit 4404 may perform uni-directional prediction for the current video block, and motion estimation unit 4404 may search reference pictures of list 0 or list 1 for a reference video block for the current video block. Motion estimation unit 4404 may then generate a reference index that indicates the reference picture in list 0 or list 1 that contains the reference video block and a motion vector that indicates a spatial displacement between the current video block and the reference video block. Motion estimation unit 4404 may output the reference index, a prediction direction indicator, and the motion vector as the motion information of the current video block. Motion compensation unit 4405 may generate the predicted video block of the current block based on the reference video block indicated by the motion information of the current video block.

[0150] In other examples, motion estimation unit 4404 may perform bi-directional prediction for the current video block, motion estimation unit 4404 may search the reference pictures in list 0 for a reference video block for the current video block and may also search the reference pictures in list 1 for another reference video block for the current video block. Motion estimation unit 4404 may then generate reference indexes that indicate the reference pictures in list 0 and list 1 containing the reference video blocks and motion vectors that indicate spatial displacements between the reference video blocks and the current video block. Motion estimation unit 4404 may output the reference indexes and the motion vectors of the current video block as the motion information of the current video block. Motion compensation unit 4405 may generate the predicted video block of the current video block based on the reference video blocks indicated by the motion information of the current video block.

[0151] In some examples, motion estimation unit 4404 may output a full set of motion information for decoding processing of a decoder. In some examples, motion estimation unit 4404 may not output a full set of motion information for the current video. Rather, motion estimation unit 4404 may signal the motion information of the current video block with reference to the motion information of another video block. For example, motion estimation unit 4404 may determine that the motion information of the current video block is sufficiently similar to the motion information of a neighboring video block.

[0152] In one example, motion estimation unit 4404 may indicate, in a syntax structure associated with the current video block, a value that indicates to the video decoder 4500 that the current video block has the same motion information as another video block.

[0153] In another example, motion estimation unit 4404 may identify, in a syntax structure associated with the current video block, another video block and a motion vector difference (MVD). The motion vector difference indicates a difference between the motion vector of the current video block and the motion vector of the indicated video block. The video decoder 4500 may use the motion vector of the indicated video block and the motion vector difference to determine the motion vector of the current video block.

[0154] As discussed above, video encoder 4400 may predictively signal the motion vector. Two examples of predictive signaling techniques that may be implemented by video encoder 4400 include advanced motion vector prediction (AMVP) and merge mode signaling.

[0155] Intra prediction unit 4406 may perform intra prediction on the current video block. When intra prediction unit 4406 performs intra prediction on the current video block, intra prediction unit 4406 may generate prediction data for the current video block based on decoded samples of other video blocks in the same picture. The prediction data for the current video block may include a predicted video block and various syntax elements.

[0156] Residual generation unit 4407 may generate residual data for the current video block by subtracting the predicted video block(s) of the current video block from the current video block. The residual data of the current video block may include residual video blocks that correspond to different sample components of the samples in the current video block.

[0157] In other examples, there may be no residual data for the current video block for the current video block, for example in a skip mode, and residual generation unit 4407 may not perform the subtracting operation.

[0158] Transform processing unit 4408 may generate one or more transform coefficient video blocks for the current video block by applying one or more transforms to a residual video block associated with the current video block.

[0159] After transform processing unit 4408 generates a transform coefficient video block associated with the current video block, quantization unit 4409 may quantize the transform coefficient video block associated with the current video block based on one or more quantization parameter (QP) values associated with the current video block.

[0160] Inverse quantization unit 4410 and inverse transform unit 4411 may apply inverse quantization and inverse transforms to the transform coefficient video block, respectively, to reconstruct a residual video block from the transform coefficient video block. Reconstruction unit 4412 may add the reconstructed residual video block to corresponding samples from one or more predicted video blocks generated by the prediction unit 4402 to produce a reconstructed video block associated with the current block for storage in the buffer 4413.

[0161] After reconstruction unit 4412 reconstructs the video block, the loop filtering operation may be performed to reduce video blocking artifacts in the video block.

[0162] Entropy encoding unit 4414 may receive data from other functional components of the video encoder 4400. When entropy encoding unit 4414 receives the data, entropy encoding unit 4414 may perform one or more entropy encoding operations to generate entropy encoded data and output a bitstream that includes the entropy encoded data.

[0163] FIG.6 is a block diagram illustrating an example of video decoder 4500 which may be video decoder 4324 in the system 4300 illustrated in FIG.4. The video decoder 4500 may be configured to perform any or all of the techniques of this disclosure. In the example shown, the video decoder 4500 includes a plurality of functional components. The techniques described in this disclosure may be shared among the various components of the videodecoder 4500. In some examples, a processor may be configured to perform any or all of the techniques described in this disclosure.

[0164] In the example shown, video decoder 4500 includes an entropy decoding unit 4501, a motion compensation unit 4502, an intra prediction unit 4503, an inverse quantization unit 4504, an inverse transformation unit 4505, a reconstruction unit 4506, and a buffer 4507. Video decoder 4500 may, in some examples, perform a decoding pass generally reciprocal to the encoding pass described with respect to video encoder 4400.

[0165] Entropy decoding unit 4501 may retrieve an encoded bitstream. The encoded bitstream may include entropy coded video data (e.g., encoded blocks of video data). Entropy decoding unit 4501 may decode the entropy coded video data, and from the entropy decoded video data, motion compensation unit 4502 may determine motion information including motion vectors, motion vector precision, reference picture list indexes, and other motion information. Motion compensation unit 4502 may, for example, determine such information by performing the AMVP and merge mode.

[0166] Motion compensation unit 4502 may produce motion compensated blocks, possibly performing interpolation based on interpolation filters. Identifiers for interpolation filters to be used with sub-pixel precision may be included in the syntax elements.

[0167] Motion compensation unit 4502 may use interpolation filters as used by video encoder 4400 during encoding of the video block to calculate interpolated values for sub-integer pixels of a reference block. Motion compensation unit 4502 may determine the interpolation filters used by video encoder 4400 according to received syntax information and use the interpolation filters to produce predictive blocks.

[0168] Motion compensation unit 4502 may use some of the syntax information to determine sizes of blocks used to encode frame(s) and / or slice(s) of the encoded video sequence, partition information that describes how each macroblock of a picture of the encoded video sequence is partitioned, modes indicating how each partition is encoded, one or more reference frames (and reference frame lists) for each inter coded block, and other information to decode the encoded video sequence.

[0169] Intra prediction unit 4503 may use intra prediction modes for example received in the bitstream to form a prediction block from spatially adjacent blocks. Inverse quantization unit 4504 inverse quantizes, i.e., de- quantizes, the quantized video block coefficients provided in the bitstream and decoded by entropy decoding unit 4501. Inverse transform unit 4505 applies an inverse transform.

[0170] Reconstruction unit 4506 may sum the residual blocks with the corresponding prediction blocks generated by motion compensation unit 4502 or intra prediction unit 4503 to form decoded blocks. If desired, a deblocking filter may also be applied to filter the decoded blocks in order to remove blockiness artifacts. The decoded video blocks are then stored in buffer 4507, which provides reference blocks for subsequent motion compensation / intra prediction and also produces decoded video for presentation on a display device.

[0171] FIG. 7 is a schematic diagram of an example encoder 4600. The encoder 4600 is suitable for implementing the techniques of VVC. The encoder 4600 includes three in-loop filters, namely a deblocking filter(DF) 4602, a sample adaptive offset (SAO) 4604, and an adaptive loop filter (ALF) 4606. Unlike the DF 4602, which uses predefined filters, the SAO 4604 and the ALF 4606 utilize the original samples of the current picture to reduce the mean square errors between the original samples and the reconstructed samples by adding an offset and by applying a finite impulse response (FIR) filter, respectively, with coded side information signaling the offsets and filter coefficients. The ALF 4606 is located at the last processing stage of each picture and can be regarded as a tool trying to catch and fix artifacts created by the previous stages.

[0172] The encoder 4600 further includes an intra prediction component 4608 and a motion estimation / compensation (ME / MC) component 4610 configured to receive input video. The intra prediction component 4608 is configured to perform intra prediction, while the ME / MC component 4610 is configured to utilize reference pictures obtained from a reference picture buffer 4612 to perform inter prediction. Residual blocks from inter prediction or intra prediction are fed into a transform (T) component 4614 and a quantization (Q) component 4616 to generate quantized residual transform coefficients, which are fed into an entropy coding component 4618. The entropy coding component 4618 entropy codes the prediction results and the quantized transform coefficients and transmits the same toward a video decoder (not shown). Quantization components output from the quantization component 4616 may be fed into an inverse quantization (IQ) components 4620, an inverse transform component 4622, and a reconstruction (REC) component 4624. The REC component 4624 is able to output images to the DF 4602, the SAO 4604, and the ALF 4606 for filtering prior to those images being stored in the reference picture buffer 4612.

[0173] FIG.8 is a flowchart for an example method 4700 of video processing. The method 4700 determines rendering information is signalled in a rendering information syntax structure included in a picture header of a JPEG AI codestream at step 4702. A conversion between a visual media data and the JPEG AI codestream is perfomed based on the rendering information syntax structure at step 4704. The conversion may include encoding at an encoder, decoding at a decoder, or combinations thereof.

[0174] It should be noted that the method 4700 can be implemented in an apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, such as video encoder 4400, video decoder 4500, and / or encoder 4600. In such a case, the instructions upon execution by the processor, cause the processor to perform the method 4700. Further, the method 4700 can be performed by a non-transitory computer readable medium comprising a computer program product for use by a video coding device. The computer program product comprises computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method 4700.

[0175] A listing of solutions preferred by some examples is provided next.

[0176] The following solutions show examples of techniques discussed herein.

[0177] 1. A method for processing media data comprising: determining one or more of coding-independent code points (CICP) rendering information, mastering display color volume information, content light level information, and dynamic metadata is contained in a rendering information syntax structure included in a pictureheader of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and performing a conversion between a visual media data and the JPEG AI codestream based on the rendering information syntax structure.

[0178] 2. The method of solution 1, wherein no rendering information header marker syntax element is signalled in the rendering information syntax structure.

[0179] 3. The method of any of solutions 1-2, wherein the JPEG AI codestream signals less than all of the CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata.

[0180] 4. The method of any of solutions 1-3, wherein an indication is included the JPEG AI codestream for a particular type of rendering information to indicate whether the particular type of rendering information is present.

[0181] 5. The method of any of solutions 1-4, wherein for each type of rendering information, an indication is included the JPEG AI codestream to indicate whether the corresponding type of rendering information is present.

[0182] 6. The method of any of solutions 1-5, wherein a syntax structure for the CICP rendering information includes an integer number of bytes.

[0183] 7. The method of any of solutions 1-6, wherein a 7-bit syntax element, named cicp_reserved_zero_7bits, is included in the syntax structure for the CICP rendering information immediately after a image_full_range_flag syntax element.

[0184] 8. The method of any of solutions 1-7, wherein a 7-bit syntax element, named cicp_reserved_zero_7bits, is included in the syntax structure for the CICP rendering information immediately before a image_full_range_flag syntax element.

[0185] 9. The method of any of solutions 1-8, wherein the dynamic metadata rendering information is signalled by a syntax structure in the JPEG AI codestream, the syntax structure comprising, in order, an indication of a dynamic metadata type, an indication of a size of a dynamic metadata, and data bytes of the dynamic metadata.

[0186] 10. The method of any of solutions 1-9, wherein a dynamic metadata type is indicated by an 8-bit syntax element named dm_type.

[0187] 11. The method of any of solutions 1-10, wherein dm_type equal to a particular value zero, specifies that the dynamic metadata is a ST2094-10_data() structure.

[0188] 12. The method of any of solutions 1-11, wherein some values of dm_type are reserved.

[0189] 13. The method of any of solutions 1-12, wherein the value of dm_type shall be equal to 0 for conforming JPEG AI codestreams.

[0190] 14. The method of any of solutions 1-13, wherein when encountering dm_type greater than 0, conforming decoders shall ignore the dynamic_metadata() syntax structure.

[0191] 15. The method of any of solutions 1-14, wherein dynamic metadata is indicated by a 16-bit syntax element.

[0192] 16. The method of any of solutions 1-15, wherein a size of the dynamic metadata is indicated by an 8-bit syntax element

[0193] 17. The method of any of solutions 1-16, wherein a length of a syntax element indication of the size of the dynamic metadata is indicated by another 1-bit or 2-bit syntax element.

[0194] 18. The method of any of solutions 1-17, wherein the conversion includes encoding the visual media data into the JPEG AI codestream.

[0195] 19. The method of any of solutions 1-17, wherein the conversion includes decoding the visual media data from the JPEG AI codestream.

[0196] 20. An apparatus for processing video data comprising: a processor; and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to perform the method of any of solutions 1-19.

[0197] 21. A non-transitory computer readable medium comprising a computer program product for use by a video coding device, the computer program product comprising computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method of any of solutions 1-19.

[0198] 22. A non-transitory computer-readable recording medium storing a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI)codestream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining one or more of coding-independent code points (CICP) rendering information, mastering display color volume information, content light level information, and dynamic metadata is contained in a rendering information syntax structure included in a picture header of a JPEG AI codestream; and generating the JPEG AI codestream based on the determining.

[0199] 23. A method for storing bitstream of a video comprising: determining one or more of coding- independent code points (CICP) rendering information, mastering display color volume information, content light level information, and dynamic metadata is contained in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; generating the JPEG AI codestream based on the determining; and storing the JPEG AI codestream in a non-transitory computer-readable recording medium.

[0200] 24. A method, apparatus, or system described in the present document.

[0201] The following solutions show further examples of techniques discussed herein.

[0202] 1. A method for processing media data comprising: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and performing a conversion between a visual media data and the JPEG AI codestream based on the rendering information syntax structure.

[0203] 2. The method of solution 1, wherein the rendering information includes one or more of coding- independent code points (CICP), mastering display color volume information, content light level information, and dynamic metadata.

[0204] 3. The method of any of solutions 1-2, wherein no rendering information header marker syntax element is signalled in the rendering information syntax structure.

[0205] 4. The method of any of solutions 1-3, wherein the JPEG AI codestream is allowed to signal less than all of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata.

[0206] 5. The method of any of solutions 1-4, wherein an indication is included the JPEG AI codestream for a particular type of rendering information to indicate whether the particular type of rendering information is present in the JPEG AI codestream.

[0207] 6. The method of any of solutions 1-5, wherein a plurality of indications are included the JPEG AI codestream to indicate whether each of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata is present in the JPEG AI codestream.

[0208] 7. The method of any of solutions 1-6, wherein a syntax structure for the CICP rendering information includes an integer number of bytes.

[0209] 8. The method of any of solutions 1-7, wherein a 7-bit syntax element named CICP reserved zero seven bits (cicp_reserved_zero_7bits) is included in the syntax structure for the CICP rendering information immediately after an image full range flag (image_full_range_flag) syntax element.

[0210] 9. The method of any of solutions 1-7, wherein a 7-bit syntax element named CICP reserved zero seven bits (cicp_reserved_zero_7bits) is included in the syntax structure for the CICP rendering information immediately before an image full range flag (image_full_range_flag) syntax element.

[0211] 10. The method of any of solutions 1-9, wherein the rendering information includes one or more of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata, wherein the rendering information is signalled in the rendering information syntax structure in the JPEG AI codestream, wherein the rendering information syntax structure is directly included in a picture() syntax structure, and wherein a presence of the rendering information syntax structure is conditioned based on whether a value of a next M-bits immediately following another syntax structure directly present in the picture() syntax structure is equal to a value of a render information marker.

[0212] 11. The method of any of solutions 1-10, wherein M is equal to 16, and the value of the render information marker is equal to 0xff84.

[0213] 12. The method of any of solutions 1-11, wherein the rendering information syntax structure includes an N-bit first syntax element (SE_1) and a second syntax element (SE_2), wherein the SE_1 indicates a length, in bytes, of the SE_2, a number of presence flags indicating the presence of the different types of renderinginformation, a number of reserved bits, and wherein the SE_2 indicates a size, in bytes, of all remaining data after a last of the SE_1, the presence flag, the reserved bits, and the SE_2 in the rendering information syntax structure.

[0214] 13. The method of any of solutions 1-12, wherein a sum of the number of presence flags (N) and the number of reserved bits is an integer times eight or is equal to eight.

[0215] 14. The method of any of solutions 1-13, wherein N is 2, the number of presence flags is 4, the number of reserved bits is 2, and values of 0, 1, 2, and 3 of SE_1 indicates the lengths of SE_2 are 1, 2, 3, and 4 bytes, respectively.

[0216] 15. The method of any of solutions 1-14, wherein the rendering information syntax structure includes an X-bit SE_1 indicating a size, in bytes, of all remaining data after a last of SE_1 and a number of presence flags indicating a presence of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata, and wherein a sum of X and the number of the presence flags is an integer times eight.

[0217] 16. The method of any of solutions 1-15, wherein X is equal to 24.

[0218] 17. The method of any of solutions 1-16, wherein CICP rendering information is included in a CICP rendering information syntax structure, and wherein the CICP rendering information syntax structure includes a syntax element that carries a chroma 4:2:0 sample location type (Chroma420SampleLocType) coded using three bits or four bits.

[0219] 18. The method of any of solutions 1-17, wherein CICP rendering information is included in a CICP rendering information syntax structure, wherein the CICP rendering information syntax structure includes a third syntax element (SE_3) that includes a Chroma420SampleLocType, and wherein when a chroma format is not 4:2:0, semantics of SE_3 are unspecified and a decoder shall ignore a value of SE_3.

[0220] 19. The method of any of solutions 1-18, wherein the SE_3 is conditionally signalled, and wherein the SE_3 is present in the CICP rendering information syntax structure only when the chroma format is 4:2:0.

[0221] 20. The method of any of solutions 1-19, wherein zero or more byte-alignment bits are appended at an end of the CICP rendering information syntax structure until a total number of bits in the CICP rendering information syntax structure is an integer times eight.

[0222] 21. The method of any of solutions 1-20, wherein zero or more byte-alignment bits are appended at an end of the rendering information syntax structure until a total number of bits in the rendering information syntax structure is an integer times eight.

[0223] 22. The method of any of solutions 1-21, wherein the conversion includes encoding the visual media data into the JPEG AI codestream.

[0224] 23. The method of any of solutions 1-21, wherein the conversion includes decoding the visual media data from the JPEG AI codestream.

[0225] 24. An apparatus for processing video data comprising: a processor; and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to perform the method of any of solutions 1-23.

[0226] 25. A non-transitory computer readable medium comprising a computer program product for use by a video coding device, the computer program product comprising computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method of any of solutions 1-23.

[0227] 26. A non-transitory computer-readable recording medium storing a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI)codestream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and generating the JPEG AI codestream based on the determining.

[0228] 27. A method for storing bitstream of a video comprising: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; generating the JPEG AI codestream based on the determining; and storing the JPEG AI codestream in a non-transitory computer-readable recording medium.

[0229] In the solutions described herein, an encoder may conform to the format rule by producing a coded representation according to the format rule. In the solutions described herein, a decoder may use the format rule to parse syntax elements in the coded representation with the knowledge of presence and absence of syntax elements according to the format rule to produce decoded video.

[0230] In the present document, the term “video processing” may refer to video encoding, video decoding, video compression or video decompression. For example, video compression algorithms may be applied during conversion from pixel representation of a video to a corresponding bitstream representation or vice versa. The bitstream representation of a current video block may, for example, correspond to bits that are either co-located or spread in different places within the bitstream, as is defined by the syntax. For example, a macroblock may be encoded in terms of transformed and coded error residual values and also using bits in headers and other fields in the bitstream. Furthermore, during conversion, a decoder may parse a bitstream with the knowledge that some fields may be present, or absent, based on the determination, as is described in the above solutions. Similarly, an encoder may determine that certain syntax fields are or are not to be included and generate the coded representation accordingly by including or excluding the syntax fields from the coded representation.

[0231] The disclosed and other solutions, examples, embodiments, modules and the functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readablemedium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine- generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.

[0232] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0233] The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0234] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random-access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and compact disc read-onlymemory (CD ROM) and Digital versatile disc-read only memory (DVD-ROM) disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0235] While this patent document contains many specifics, these should not be construed as limitations on the scope of any subject matter or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular techniques. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0236] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

[0237] Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document.

[0238] A first component is directly coupled to a second component when there are no intervening components, except for a line, a trace, or another medium between the first component and the second component. The first component is indirectly coupled to the second component when there are intervening components other than a line, a trace, or another medium between the first component and the second component. The term “coupled” and its variants include both directly coupled and indirectly coupled. The use of the term “about” means a range including ±10% of the subsequent number unless otherwise stated.

[0239] While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.

[0240] In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled may be directly connected or may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions,and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.

Claims

CLAIMS What is claimed is:

1. A method for processing media data comprising: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and performing a conversion between a visual media data and the JPEG AI codestream based on the rendering information syntax structure.

2. The method of claim 1, wherein the rendering information includes one or more of coding-independent code points (CICP), mastering display color volume information, content light level information, and dynamic metadata.

3. The method of any of claims 1-2, wherein no rendering information header marker syntax element is signalled in the rendering information syntax structure.

4. The method of any of claims 1-3, wherein the JPEG AI codestream is allowed to signal less than all of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata.

5. The method of any of claims 1-4, wherein an indication is included the JPEG AI codestream for a particular type of rendering information to indicate whether the particular type of rendering information is present in the JPEG AI codestream.

6. The method of any of claims 1-5, wherein a plurality of indications are included the JPEG AI codestream to indicate whether each of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata is present in the JPEG AI codestream.

7. The method of any of claims 1-6, wherein a syntax structure for the CICP rendering information includes an integer number of bytes.

8. The method of any of claims 1-7, wherein a 7-bit syntax element named CICP reserved zero seven bits (cicp_reserved_zero_7bits) is included in the syntax structure for the CICP rendering information immediately after an image full range flag (image_full_range_flag) syntax element.

9. The method of any of claims 1-7, wherein a 7-bit syntax element named CICP reserved zero seven bits (cicp_reserved_zero_7bits) is included in the syntax structure for the CICP rendering information immediately before an image full range flag (image_full_range_flag) syntax element.

10. The method of any of claims 1-9, wherein the rendering information includes one or more of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata, wherein the rendering information is signalled in the rendering information syntax structure in the JPEG AI codestream, wherein the rendering information syntax structure is directly included in a picture() syntax structure, and wherein a presence of the rendering information syntax structure is conditioned based on whether a value of a next M-bits immediately following another syntax structure directly present in the picture() syntax structure is equal to a value of a render information marker.

11. The method of any of claims 1-10, wherein M is equal to 16, and the value of the render information marker is equal to 0xff84.

12. The method of any of claims 1-11, wherein the rendering information syntax structure includes an N-bit first syntax element (SE_1) and a second syntax element (SE_2), wherein the SE_1 indicates a length, in bytes, of the SE_2, a number of presence flags indicating the presence of the different types of rendering information, a number of reserved bits, and wherein the SE_2 indicates a size, in bytes, of all remaining data after a last of the SE_1, the presence flag, the reserved bits, and the SE_2 in the rendering information syntax structure.

13. The method of any of claims 1-12, wherein a sum of the number of presence flags (N) and the number of reserved bits is an integer times eight or is equal to eight.

14. The method of any of claims 1-13, wherein N is 2, the number of presence flags is 4, the number of reserved bits is 2, and values of 0, 1, 2, and 3 of SE_1 indicates the lengths of SE_2 are 1, 2, 3, and 4 bytes, respectively.

15. The method of any of claims 1-14, wherein the rendering information syntax structure includes an X-bit SE_1 indicating a size, in bytes, of all remaining data after a last of SE_1 and a number of presence flags indicating a presence of CICP rendering information, mastering display color volume information, content light level information, and dynamic metadata, and wherein a sum of X and the number of the presence flags is an integer times eight.

16. The method of any of claims 1-15, wherein X is equal to 24.

17. The method of any of claims 1-16, wherein CICP rendering information is included in a CICP rendering information syntax structure, and wherein the CICP rendering information syntax structure includes a syntax element that carries a chroma 4:2:0 sample location type (Chroma420SampleLocType) coded using three bits or four bits.

18. The method of any of claims 1-17, wherein CICP rendering information is included in a CICP rendering information syntax structure, wherein the CICP rendering information syntax structure includes a third syntax element (SE_3) that includes a Chroma420SampleLocType, and wherein when a chroma format is not 4:2:0, semantics of SE_3 are unspecified and a decoder shall ignore a value of SE_3.

19. The method of any of claims 1-18, wherein the SE_3 is conditionally signalled, and wherein the SE_3 is present in the CICP rendering information syntax structure only when the chroma format is 4:2:

0.

20. The method of any of claims 1-19, wherein zero or more byte-alignment bits are appended at an end of the CICP rendering information syntax structure until a total number of bits in the CICP rendering information syntax structure is an integer times eight.

21. The method of any of claims 1-20, wherein zero or more byte-alignment bits are appended at an end of the rendering information syntax structure until a total number of bits in the rendering information syntax structure is an integer times eight.

22. The method of any of claims 1-21, wherein the conversion includes encoding the visual media data into the JPEG AI codestream.

23. The method of any of claims 1-21, wherein the conversion includes decoding the visual media data from the JPEG AI codestream.

24. An apparatus for processing video data comprising: a processor; and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to perform the method of any of claims 1-23.

25. A non-transitory computer readable medium comprising a computer program product for use by a video coding device, the computer program product comprising computer executable instructions stored on the non- transitory computer readable medium such that when executed by a processor cause the video coding device to perform the method of any of claims 1-23.

26. A non-transitory computer-readable recording medium storing a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI)codestream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; and generating the JPEG AI codestream based on the determining.

27. A method for storing bitstream of a video comprising: determining rendering information is signalled in a rendering information syntax structure included in a picture header of a Joint Photographic Experts Group (JPEG) Artificial Intelligence (AI) codestream; generating the JPEG AI codestream based on the determining; and storing the JPEG AI codestream in a non-transitory computer-readable recording medium.

Images