Video encoding device and video decoding device

Abstract

To provide a moving image encoding device and decoding device that can guarantee that a process can be executed at an expected processing speed, even when a neural network is used to perform a super-resolution process since the complexity of the process can be known.SOLUTION: In a moving image transmission system 1, a moving image decoding device 30 has an image decoding device 31, which decodes encoded data produced by encoding an image that has been subjected to a resolution conversion, an inverse conversion information decoding device 91, which decodes inverse conversion information specifying level information indicating the level of complexity of the inverse conversion process of the image decoding device, and a resolution inverse conversion device 61, which converts an image decoded by the image decoding device to the resolution before encoding using the inverse conversion information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a video encoding device and a video decoding device. [Background technology]

[0002] In order to efficiently transmit or record moving images, a moving image encoding device is used that generates encoded data by encoding moving images, and a moving image decoding device is used that generates a decoded image by decoding the encoded data.

[0003] Specific examples of video encoding methods include H.264 / AVC and H.265 / HEVC (High-Efficiency Video Coding).

[0004] In such a video coding method, images (pictures) constituting a video are divided into slices obtained by dividing the images, coding tree units (CTUs) obtained by dividing the slices, coding tree units (CTUs) obtained by dividing the coding tree units, and so on. The coding unit (sometimes called a coding unit (CU)) that is to be encoded, and The coding unit is divided into transform units (TUs), which are managed in a hierarchical structure, and the coding unit is encoded / decoded for each CU.

[0005] In such a video coding method, a predicted image is usually generated based on a locally decoded image obtained by encoding / decoding an input image, and a prediction error (sometimes called a "difference image" or "residual image") obtained by subtracting the predicted image from the input image (original image) is coded. Methods for generating a predicted image include inter-prediction and intra-prediction.

[0006] Moreover, Non-Patent Document 1 can be cited as a recent example of a video encoding and decoding technique.

[0007] Non-Patent Document 1 specifies the RPR (Reference Picture Re-sampling) technology that enables variable image resolution encoding and decoding. Furthermore, Annex D of Non-Patent Document 1 specifies supplemental enhancement information SEI for transmitting image properties, display methods, timing, and the like simultaneously with encoded data.

[0008] In Non-Patent Document 2, neural network parameters are added to the additional information SEI on the decoding side. A technology has been proposed in which the decoded image is super-resolutioned by transmitting the image to a [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] ITU-T Recommendation H.266 (08 / 20) 2020-08-29 [Non-Patent Document 2] T. Chujoh, E. Sasaki and T. Ikai, AHG9 / AHG11: Neural network based super resolution SEI, JVET Document, JVET-T0092, Oct. 2020. Summary of the Invention [Problem to be solved by the invention]

[0010] However, when the RPR method described in Non-Patent Document 1 is used, at least a part of the input image is When reducing the resolution of an image, encoding and decoding it, and then returning it to the original resolution (the same as the input image), there is a problem that blurring is likely to occur.

[0011] In addition, the neural network parameters in Non-Patent Document 2 are decoded using the additional information SEI. However, the technology of transmitting the network parameters to the external network and super-resolving the decoded image has the problem that it is not possible to guarantee that the expected processing speed can be achieved because it is not possible to know the complexity of performing super-resolution processing using the transmitted network parameters. [Means for solving the problem]

[0012] A video decoding device according to one aspect of the present invention includes: an image decoding device that decodes encoded data obtained by encoding an image that has been subjected to resolution conversion; an inverse transformation information decoding device that decodes inverse transformation information that specifies level information indicating a complexity of an inverse transformation process of the image decoding device; The image decoding device further includes a resolution inverse conversion device that converts the image decoded by the image decoding device to a resolution before encoding using the inverse conversion information.

[0013] The inverse transformation information decoding device is characterized in that it decodes the inverse transformation information using auxiliary information as an input.

[0014] The inverse transformation information decoding device may be characterized in that it receives encoded data as an input and decodes the inverse transformation information.

[0015] A video encoding device according to one aspect of the present invention comprises: a resolution conversion device for converting the resolution of an input image signal; an image encoding device that encodes the image whose resolution has been converted by the resolution conversion device; an inverse transformation information generating device for generating inverse transformation information that specifies level information indicating a degree of complexity of an inverse transformation process of the image encoding device; The inverse transformation information coding device includes an inverse transformation information coding device for coding the inverse transformation information.

[0016] The inverse transformation information coding device is characterized in that it codes the inverse transformation information as auxiliary information.

[0017] The inverse transformation information coding device is characterized in that it codes the inverse transformation information as coded data. Effect of the Invention

[0018] By using this type of configuration, even when super-resolution processing is performed using a neural network, the complexity of the processing can be determined, solving the problem of not being able to guarantee that the processing can be performed at the expected processing speed. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing a configuration of a video transmission system according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing the configuration of a transmitting device equipped with a video encoding device according to the present embodiment, and a receiving device equipped with a video decoding device, in which PROD_A indicates the transmitting device equipped with the video encoding device, and PROD_B indicates the receiving device equipped with the video decoding device. [Diagram 3] 1 is a diagram showing the configuration of a recording device equipped with a video encoding device according to the present embodiment, and a playback device equipped with a video decoding device, in which PROD_C indicates a recording device equipped with a video encoding device, and PROD_D indicates a playback device equipped with a video decoding device. [Figure 4] FIG. 2 is a diagram showing a hierarchical structure of encoded data. [Diagram 5] 1 is a conceptual diagram of an image to be processed in the video transmission system according to the present embodiment. [Figure 6] FIG. 2 is a conceptual diagram showing an example of a reference picture and a reference picture list. [Figure 7] FIG. 1 is a schematic diagram showing a configuration of an image decoding device. [Figure 8] 11 is a flowchart illustrating a schematic operation of an image decoding device. [Figure 9] FIG. 13 is a schematic diagram showing a configuration of an inter-prediction parameter derivation unit. [Figure 10] 1 is a schematic diagram showing the configuration of a merge prediction parameter derivation unit and an AMVP prediction parameter derivation unit. [Figure 11]FIG. 13 is a schematic diagram showing a configuration of an inter-prediction image generating unit. [Figure 12] FIG. 1 is a block diagram showing a configuration of an image encoding device. [Figure 13] 13 is a schematic diagram showing a configuration of an inter-prediction parameter encoding unit. [Figure 14] 11 is a table that defines level information based on the number of bytes when network parameters are coded, as the complexity of the inverse conversion process according to an embodiment. [Figure 15] 1 is a table that defines level information based on the number of network parameters as the complexity of an inverse conversion process according to an embodiment; [Figure 16] FIG. 13 is a diagram showing an example of the configuration of a syntax table of supplemental extension information that specifies level information according to an embodiment. [Figure 17] FIG. 13 is a diagram showing another example of a syntax table of supplemental extension information that specifies level information according to an embodiment. [Figure 18] FIG. 2 is a diagram showing an example of the configuration of an APS syntax table that specifies level information according to an embodiment. [Figure 19] FIG. 2 is a diagram showing an example of the configuration of an APS syntax table that specifies level information according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (First embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] FIG. 1 is a schematic diagram showing the configuration of a video transmission system according to this embodiment.

[0022] The video transmission system 1 encodes images having different resolutions, the resolutions of which have been converted. The video transmission system 1 comprises a video encoding device 10, a network 21, and a video It comprises an image decoding device 30 and an image display device 41 .

[0023] The video encoding device 10 is made up of a resolution conversion device (resolution conversion unit) 51, an image encoding device (image encoding unit) 11, an inverse conversion information creation device (inverse conversion information creation unit) 71, and an inverse conversion information encoding device (inverse conversion information encoding unit) 81.

[0024] The video decoding device 30 includes an image decoding device (image decoding unit) 31, a resolution inverse conversion device (resolution inverse conversion unit) 61, and an inverse conversion information decoding device (inverse conversion information decoding unit) 91.

[0025] The resolution conversion device 51 converts the resolution of an image T included in a video to generate an image of a different resolution. to the image coding device 11. The resolution conversion device 51 also supplies inverse conversion information indicating whether or not the resolution of the image is converted to the image coding device 11. If the information indicates resolution conversion, the video coding device 10 sets resolution conversion information ref_pic_resampling_enabled_flag, which will be described later, to 1, and includes it in a sequence parameter set SPS (Sequence Parameter Set) of the coded data Te for coding.

[0026] The inverse conversion information creation device 71 creates inverse conversion information based on an image T1 included in a video. The inverse conversion information is derived or selected from the relationship between an input image T1 before resolution conversion and an image Td1 after resolution conversion, encoding, and decoding. The auxiliary information is information indicating what to select.

[0027] Inverse transformation information is input to the inverse transformation information encoding device 81. The inverse transformation information encoding device 81 encodes the inverse transformation information to generate encoded inverse transformation information, and transmits the encoded inverse transformation information to the network 21.

[0028] A variable resolution image T2 is input to the image encoding device 11. The image encoding device 11 encodes the image T2 in the RPR frame. The image size information of the input image is encoded in PPS units using the set, and sent to the image decoding device 31. .

[0029] In FIG. 1, the inverse transformation information coding device 81 is not connected to the image coding device 11, but the inverse transformation information coding device 81 and the image coding device 11 may communicate necessary information as appropriate.

[0030] The network 21 transmits the coded inverse transformation information and the coded data Te to the image decoding device 31. A part or all of the coded inverse transformation information is coded as supplemental enhancement information SEI. The encoded data Te may be included in the data Te. The network 21 is the Internet, a wide area network (WAN), a local area network (LAN), or a combination of these. The network 21 is not necessarily limited to a two-way communication network, and may be a one-way communication network that transmits broadcast waves such as terrestrial digital broadcasting and satellite broadcasting. The network 21 may also be replaced by a storage medium on which the encoded data Te is recorded, such as a DVD (Digital Versatile Disc: registered trademark) or a BD (Blue-ray Disc: registered trademark).

[0031] The image decoding device 31 decodes each of the encoded data Te transmitted by the network 21 , generates a variable resolution decoded image, and supplies it to the resolution inverse conversion device 61 .

[0032] The inverse conversion information decoding device 91 decodes the coded inverse conversion information transmitted by the network 21 to generate inverse conversion information, and supplies the generated inverse conversion information to the resolution inverse conversion device 61 .

[0033] 1, the inverse transformation information decoding device 91 is illustrated separately from the image decoding device 31, but the inverse transformation information decoding device 91 may be included in the image decoding device 31. For example, the inverse transformation information decoding device 91 may be included in the image decoding device 31 separately from each functional unit of the image decoding device 31. Also, although not connected to the image decoding device 31 in FIG. 1, the inverse transformation information decoding device 91 and the image decoding device 31 may communicate necessary information as appropriate.

[0034] When the resolution conversion information indicates resolution conversion, the resolution inverse conversion device 61 generates a decoded image of the original size by inversely converting the resolution-converted image through super-resolution processing using a neural network based on the image size information included in the encoded data.

[0035] The image display device 41 receives one or more decoded images Td2 from the resolution inverse conversion device 61. The image display device 41 includes a display device such as a liquid crystal display or an organic EL (Electro-luminescence) display. The display may be in the form of a stationary display, a mobile display, an HMD, or the like. When the display device has a high processing power, it displays a high quality image, and when the display device has a lower processing power, it displays an image that does not require a high processing power or display power.

[0036] Fig. 5 is a conceptual diagram of an image to be processed in the video transmission system shown in Fig. 1, showing changes in the resolution of the image over time. However, in Fig. 5, no distinction is made as to whether the image is encoded or not. Fig. 5 shows an example in which an image is transmitted to the image decoding device 31 with a reduced resolution during processing in the video transmission system. As shown in Fig. 5, the resolution conversion device 51 normally performs conversion to reduce the resolution of the image in order to reduce the amount of information to be transmitted.

[0037] <operator> The operators used in this specification are listed below.

[0038] >> is a right bit shift, << is a left bit shift, & is a bitwise AND, | is a bitwise OR , |= is the OR assignment operator, and || indicates logical OR.

[0039] x ? y : z is a ternary operator that takes y if x is true (non-zero) and z if x is false (zero). do.

[0040] Clip3(a, b, c) is a function that clips c to a value between a and b (inclusive). If c < a, it returns a; if c > b, it returns b; otherwise, it returns c (assuming a <= b).

[0041] abs(a) is a function that returns the absolute value of a.

[0042] Int(a) is a function that returns the integer value of a.

[0043] floor(a) is a function that returns the largest integer less than or equal to a.

[0044] ceil(a) is a function that returns the smallest integer greater than or equal to a.

[0045] a / d represents the division of a by d, rounded down to the nearest integer.

[0046] <Structure of the Encoded Data Te> Prior to the detailed description of the image encoding device 11 and the image decoding device 31 according to this embodiment, the data structure of the encoded data Te generated by the image encoding device 11 and decoded by the image decoding device 31 will be described.

[0047] Figure 4 is a diagram showing the hierarchical structure of the data in the encoded data Te. The encoded data Te illustratively includes a sequence and a plurality of pictures that make up the sequence. Figure 4 shows an encoded video sequence that defines a sequence SEQ, an encoded picture that defines a picture PICT, an encoded slice that defines a slice S, encoded slice data that defines slice data, an encoded tree unit included in the encoded slice data, and an encoded unit included in the encoded tree unit.

[0048] (Encoded Video Sequence) In a coded video sequence, an image decoding device is used to decode the sequence SEQ to be processed. The standard specifies a set of data referenced by the video parameter set (VPS) 31. As shown in Fig. 4, the sequence SEQ includes a video parameter set (VPS), a sequence parameter set (SPS), a picture parameter set (PPS), an adaptation parameter set (APS), a picture PICT, and supplemental enhancement information (SEI).

[0049] In the video parameter set VPS, for a video image that consists of multiple layers, A set of coding parameters common to a plurality of video streams and a set of coding parameters associated with a plurality of layers and each individual layer contained in the video stream are defined.

[0050] The sequence parameter set SPS specifies a set of coding parameters that the image decoding device 31 refers to in order to decode the target sequence. For example, the width and height of a picture are Note that multiple SPSs may exist. In that case, one of the multiple SPSs is selected from the PPS. Select.

[0051] Here, the sequence parameter set SPS includes the following syntax elements: ref_pic_resampling_enabled_flag: A flag that specifies whether or not to use a function for varying resolution (resampling) when decoding each image included in a single sequence that references the target SPS. In other words, this flag indicates that the size of the reference picture referenced in generating a predicted image changes between each image indicated by a single sequence. When the value of this flag is 1, the resampling function is enabled. is applied, if it is 0 it is not applied. pic_width_max_in_luma_samples: The maximum width of any image in a sequence. This syntax element specifies the width of the image in luminance block units. The value of this syntax element must not be 0 and must be an integer multiple of Max(8, MinCbSizeY). Here, MinCbSizeY is a value determined by the minimum size of a luminance block. pic_height_max_in_luma_samples: This syntax element specifies the height of the image with the maximum height among the images in a single sequence, in units of luminance blocks. The value of this syntax element must not be 0 and must be an integer multiple of Max(8, MinCbSizeY). is required. sps_temporal_mvp_enabled_flag: The time motion detection flag for decoding the target sequence. A flag that specifies whether or not to use vector prediction. If the value of the flag is 1, time If the value is 0, temporal motion vector prediction is not used. In addition, by defining this flag, it is possible to prevent the coordinate position to be referenced from shifting when, for example, referring to a reference picture with a different resolution.

[0052] The picture parameter set PPS specifies the number of pictures to be decoded for each picture in the target sequence. A set of coding parameters to be referred to by the image decoding device 31 is defined. For example, the reference value of the quantization width (pic_init_qp_minus26) used in decoding a picture and the application of weighted prediction are defined. A flag (weighted_pred_flag) indicating the PPS is included. Note that there may be multiple PPSs. In this case, one of multiple PPSs is selected from each picture in the target sequence.

[0053] Here, the picture parameter set PPS includes the following syntax elements: · pic_width_in_luma_samples: A syntax element that specifies the width of the target picture. The value of this syntax element is required to be a non-zero integer multiple of Max(8, MinCbSizeY) and equal to or less than pic_width_max_in_luma_samples. pic_height_in_luma_samples: A syntax element that specifies the height of the target picture. The value of this syntax element is required to be a non-zero integer multiple of Max(8, MinCbSizeY) and equal to or less than pic_height_max_in_luma_samples. · conformance_window_flag: Conformance (cropping) window offset A flag indicating whether the parameter is to be subsequently notified and where the conformance window is to be displayed. If this flag is 1, the parameter is notified. If it is 0, the conformance window offset parameter is not present. This indicates that. conf_win_left_offset, conf_win_right_offset, conf_win_top_offset, conf_win_bottom_offset: offset values ​​for specifying the left, right, top, and bottom positions of the picture output by the decoding process with respect to the rectangular area specified by the output picture coordinates. In addition, if the value of conformance_window_flag is 0, the values ​​of conf_win_left_offset, conf_win_right_offset, conf_win_top_offset, and conf_win_bottom_offset are estimated to be 0. scaling_window_flag: A flag indicating whether or not a scaling window offset parameter exists in the target PPS, and is a flag related to the specification of the output image size. When this flag is 1, it indicates that the parameter exists in the PPS, and when this flag is 0, it indicates that the parameter does not exist in the PPS. In addition, when the value of ref_pic_resampling_enabled_flag is 0, the value of scaling_window_flag must also be 0. is required. scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, scaling_win_bottom_offset: Syntax elements that specify the offsets applied to the image size for scaling ratio calculation in luma samples for the left, right, top, and bottom positions of the target picture, respectively. If the value of scaling_window_flag is 0, the values ​​of scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset are inferred to be 0. It is also required that the value of scaling_win_left_offset + scaling_win_right_offset is less than pic_width_in_luma_samples, and the value of scaling_win_top_offset + scaling_win_bottom_offset is less than pic_height_in_luma_samples.

[0054] The width PicOutputWidthL and height PicOutputHeightL of the output picture are derived as follows:

[0055] PicOutputWidthL = pic_width_in_luma_samples - (scaling_win_right_offset + scaling_win_left_offset) PicOutputHeightL = pic_height_in_pic_size_units - (scaling_win_bottom_offset + scaling_win_top_offset) In Non-Patent Document 1, the width and height of the output picture are specified, but the specific method for performing the resolution inverse conversion process is not specified. When a normal upsampling filter process is performed, there is a problem that blurring is likely to occur.

[0056] On the other hand, it is known that a super-resolution algorithm technology for moving images using a neural network can restore a high resolution without blurring compared to conventional upsampling filter processing. However, in the technology in Non-Patent Document 2, in which neural network parameters are transmitted to the decoding side in the additional information SEI and the decoded image is super-resolved, the complexity of the super-resolution process performed using the transmitted network parameters is unknown. Therefore, there is a problem in that it is not possible to guarantee that the expected processing speed can be achieved.

[0057] The inverse transformation information generating device 71 receives the input image signal T1 and a locally decoded signal in the reference image memory of the image encoding device 11, and outputs inverse transformation information.

[0058] The inverse transformation information generating device 71 identifies a plurality of pictures to be used when super-resolving the coded local image signal, and sends them to the inverse transformation information coding device 81 as inverse transformation information.

[0059] The inverse conversion information generating device 71 generates level information indicating the complexity of the inverse conversion process as the inverse conversion information. The level information indicating the complexity of the inverse conversion process includes at least one of the following conditions. Number of network parameters Network parameter bit length - Network parameter calculation accuracy - Number of bits when encoding network parameters -Number of bytes when encoding network parameters Any other index that represents the complexity of a neural network may be used.

[0060] 14 is an example of level information indicating the complexity of the inverse transform process. The level information uses the number of bytes when the network parameters are coded.

[0061] NNR_level indicates the level of inverse conversion processing using a neural network.

[0062] nnr_level_idc is the value that is coded and decoded as the level information syntax element. The integer part of NNR_level is multiplied by 16, and the decimal part of NNR_level is multiplied by 3 and then added to the result. That is why.

[0063] Max_nnr_byte is the upper limit of the number of bytes when the network parameters are encoded. For example, if the number of bytes when the network parameters are encoded is greater than 131072 bytes and less than or equal to 149263, the NNR_level is defined as 3.1.

[0064] The complexity of the inverse transform process, Nnr_complexity, is derived as follows using nnr_level_idc, general_level_idc, and nnr_parameter_scale.

[0065] Nnr_complexity = nnr_level_idc * general_level_idc * (1< <nnr_parameter_scale) Here, nnr_level_idc indicates the complexity of the network parameters. general_level_idc is the level information of the image decoding process. nnr_parameter_scale is the scale of the network parameters. This is a scaling value, which is used to adjust the number of bytes used as the unit of calculation for network parameters, and the complexity due to differences in input / output pixel bit length and image format.

[0066] Here, general_level_idc is used as the complexity value related to the number of pixels used to derive Nnr_complexity, but the maximum total number of pixels calculated from sps_pic_width_max_in_luma_samples, sps_pic_height_max_in_luma_samples, and sps_chroma_format_idc multiplied by the pixel bit length (sps_bitdepth_minus8+8) may be used. sps_pic_width_max_in_luma_samples is the sps_pic_height_max_in_luma_samples is the maximum horizontal size of a sequence-level picture, sps_pic_height_max_in_luma_samples is the maximum vertical size of a sequence-level picture, sps_chroma_format_idc is the chroma It is a format.

[0067] Also, for sublayers, use sublayer_level_idc[i] instead of general_level_idc.

[0068] 15 shows another example of level information indicating the complexity of the inverse conversion process, in which the number of network parameters is used as the level information.

[0069] In this case, Max_nn_param represents the upper limit of the number of network parameters. Similar to Max_nnr_byte in Fig. 14, the complexity Nnr_complexity of the inverse conversion process can be derived by defining NNR_level based on the number of network parameters.

[0070] The inverse transform coding device 81 encodes the level information (nnr_level_idc, nnr_parameter_scale) sent as the inverse transform information based on the syntax of Figure 16, Figure 17, or Figure 18 and Figure 19. In the case of the syntax of Figure 16 or Figure 17, the inverse transform information is encoded as SEI, multiplexed into the encoded data Te output by the image coding device 11, and output to the network 21. In the case of the syntax of Figure 18 and Figure 19, the inverse transform information is encoded as APS, and output as part of the encoded data Te output by the image coding device 11.

[0071] The inverse transformation information decoding device 91 decodes the encoded data Te from the network 21 into inverse transformation information based on the syntax of Figures 16, 17, or 18 and 19, and sends the decoded result to the resolution inverse conversion device 61. In the case of the syntax of Figures 16 and 17, the inverse transformation information encoded as SEI is decoded. In the case of the syntax in Figures 18 and 19, the inverse transformation information is encoded as APS. Decrypt the information.

[0072] The resolution inverse conversion device 61 uses inverse conversion information to inversely convert the resolution of Td1 based on the image size information of the image Td1 decoded by the image decoding device 31 and the decoded result of the image size information of the input image T1 coded in PPS units, and generates a decoded image Td2. This is level information indicating the level of complexity.

[0073] With this configuration, the level information inverse conversion information indicating the complexity of the inverse conversion process is encoded and decoded as auxiliary information or encoded data. Therefore, the complexity of the super-resolution process can be known, so that the resolution inverse conversion process can be appropriately performed.

[0074] (Encoded Picture) The coded picture defines a set of data to be referenced by the image decoding device 31 in order to decode the picture PICT to be processed. The picture PICT is, as shown in FIG. PH, including slices 0 to NS-1 (NS is the total number of slices contained in the picture PICT) .

[0075] In the following, when there is no need to distinguish between slices 0 to NS-1, the subscripts of the signs are The same applies to other data that is included in the encoded data Te described below and has a subscript attached thereto.

[0076] The picture header contains the following syntax elements: pic_temporal_mvp_enabled_flag: The image of the slice associated with the picture header. A flag that specifies whether or not to use temporal motion vector prediction for center prediction. If the value of the flag is 0, the syntax element The flag restricts the decoding of the slice to not use temporal motion vector prediction. If the flag has a value of 1, it indicates that temporal motion vector prediction is used to decode the slice associated with the picture header. If the flag is not specified, the value is inferred to be 0.

[0077] (Coded Slice) In the case of the coded slice, the image decoding device 31 refers to the coded slice S to decode the slice S to be processed. As shown in Figure 4, a slice consists of a slice header and and contains slice data.

[0078] The slice header includes a group of coding parameters to be referred to by the image decoding device 31 in order to determine a decoding method for the current slice. Slice type designation information (slice_type) that designates a slice type is an example of a coding parameter included in the slice header.

[0079] Slice types that can be specified by the slice type specification information include (1) an I slice that uses only intra prediction when encoding, (2) a P slice that uses uni-prediction (L0 prediction) or intra prediction when encoding, and (3) a B slice that uses uni-prediction (L0 prediction or L1 prediction), bi-prediction, or intra prediction when encoding. Note that inter prediction is not limited to uni-prediction or bi-prediction, and a predicted image may be generated using more reference pictures. Hereinafter, when referring to P or B slice, it refers to a slice including a block that can use inter prediction.

[0080] In addition, the slice header may include a reference to a picture parameter set PPS (pic_parameter_set_id).

[0081] (Encoded slice data) The coded slice data defines a set of data to be referenced by the image decoding device 31 in order to decode the slice data to be processed. The slice data is the coded slice data shown in FIG. As shown in the header, it contains a CTU. A CTU is a block of fixed size (e.g. 64x64) that constitutes a slice, and is also called a Largest Coding Unit (LCU). do.

[0082] (coding tree unit) 4 specifies a set of data that the image decoding device 31 refers to in order to decode a CTU to be processed. The CTU is divided into coding units CU, which are basic units of encoding processing, by recursive quad tree division (QT (Quad Tree) division), binary tree division (BT (Binary Tree) division), or ternary tree division (TT (Ternary Tree) division). BT division and TT division are collectively called multi tree division (MT (Multi Tree) division). A node of a tree structure obtained by recursive quad tree division is called a coding node. Intermediate nodes of a quad tree, binary tree, and ternary tree are coding nodes, and the CTU itself is specified as the top coding node.

[0083] The CT includes, as CT information, a CU split flag (split_cu_flag) indicating whether or not to split the CT, a QT split flag (split_cu_flag) indicating whether or not to split the CT, The flags include a QT split flag (qt_split_cu_flag) indicating whether or not to split the MT, an MT split direction (mtt_split_cu_vertical_flag) indicating the split direction of the MT, and an MT split type (mtt_split_cu_binary_flag) indicating the split type of the MT. split_cu_flag, qt_split_cu_flag, mtt_split_cu_vertical_flag, and mtt_split_cu_binary_flag are transmitted for each encoding node.

[0084] Different trees may be used for luminance and chrominance. The type of tree is indicated by treeType. For example, when using a common tree for luminance (Y, cIdx=0) and chrominance (Cb / Cr, cIdx=1,2), the common single tree is indicated by treeType=SINGLE_TREE. When using two different trees (DUAL trees) for luminance and chrominance, the luminance tree is indicated by treeType=DUAL_TREE_LUMA and the chrominance tree is indicated by treeType=DUAL_TREE_CHROMA.

[0085] (Encoding Unit) FIG. 4 shows data to be referenced by the image decoding device 31 in order to decode the coding unit to be processed. Specifically, a CU consists of a CU header CUH, prediction parameters, and transformation parameters. The CU header includes a quantization transform coefficient, a quantization metric, etc. The CU header specifies a prediction mode, etc.

[0086] The prediction process may be performed on a CU basis, or on a sub-CU basis by further dividing a CU. If the size of a CU and a sub-CU are the same, there is one sub-CU in the CU. If the size of a CU is larger than that of a sub-CU, the CU is divided into sub-CUs. For example, if the CU is 8x8 and the sub-CU is 4x4, the CU is divided into 2 parts horizontally and 2 parts vertically, into 4 sub-CUs.

[0087] There are two types of prediction (prediction modes): intra prediction and inter prediction. Intra prediction is a prediction within the same picture, while inter prediction refers to a prediction process performed between different pictures (for example, between display times or between layer images).

[0088] Transformation and quantization are performed in units of CUs, but quantization coefficients are stored in units of subblocks such as 4x4. It may be entropy coded.

[0089] (Prediction parameters) The predicted image is derived from prediction parameters associated with the block, which include intra-prediction and inter-prediction parameters.

[0090] Hereinafter, prediction parameters of inter prediction will be described. Inter prediction parameters are composed of prediction list use flags predFlagL0 and predFlagL1, reference picture indexes refIdxL0 and refIdxL1, and motion vectors mvL0 and mvL1. predFlagL0 and predFlagL1 are flags indicating whether or not a reference picture list (L0 list, L1 list) is used, and when the value is 1, the corresponding reference picture list is used. Note that in this specification, when "a flag indicating whether or not XX" is written, a flag other than 0 (for example, 1) is XX, 0 is not XX, and 1 is treated as true and 0 is treated as false in logical negation, logical product, etc. (similarly below). However, in an actual device or method, other values ​​can be used as true and false values.

[0091] Syntax elements for deriving inter prediction parameters include, for example, an affine flag affine_flag used in the merge mode, a merge flag merge_flag, a merge index merge_idx, an MMVD flag mmvd_flag, and an index for selecting a reference picture used in the AMVP mode. Inter prediction identifier inter_pred_idc, reference picture index refIdxLX, predicted vector index mvp_LX_idx for deriving a motion vector, difference vector mvdLX, motion vector There is a rule precision mode amvr_mode.

[0092] (See picture list) The reference picture list is a list of reference pictures stored in the reference picture memory 306. FIG. 6 is a conceptual diagram showing an example of a reference picture and a reference picture list. In the conceptual diagram showing an example of a reference picture in FIG. 6, a rectangle indicates a picture, an arrow indicates a reference relationship between pictures, the horizontal axis indicates time, I, P, and B in the rectangle indicate an intra picture, a uni-predictive picture, and a bi-predictive picture, respectively, and numbers in the rectangle indicate a decoding order. As shown in the figure, the decoding order of pictures is I0, P1, B2, B3, and B4, and the display order is I0, B3, B2, B4, and P1. FIG. 6 shows an example of a reference picture list of picture B3 (target picture). A reference picture list is a list representing candidates for a reference picture, and one picture (slice) may have one or more reference picture lists. In the example shown in the figure, the target picture B3 has two reference picture lists, an L0 list RefPicList0 and an L1 list RefPicList1. In each CU, refIdxLX specifies which picture in the reference picture list RefPicListX (X=0 or 1) is actually referenced. The diagram shows an example where refIdxL0=2 and refIdxL1=0. Note that LX is a description method used when there is no distinction between L0 prediction and L1 prediction, and hereinafter, parameters for the L0 list and parameters for the L1 list are distinguished by replacing LX with L0 and L1.

[0093] (Merge prediction and AMVP prediction) The prediction parameter decoding (encoding) method includes a merge prediction mode and an AMVP (Advanced Motion Vector Prediction) mode, and merge_flag is a flag for identifying these. The merge prediction mode is a mode in which the prediction list usage flag predFlagLX, the reference picture index refIdxLX, and the motion vector mvLX are not included in the encoded data, but are derived from the prediction parameters of the neighboring blocks that have already been processed. The AMVP mode is a mode in which inter_pred_idc, refIdxLX, and mvLX are included in the encoded data. Note that mvLX is encoded as mvp_LX_idx, which identifies the prediction vector mvpLX, and the difference vector mvdLX. In addition to the merge prediction mode, there may be an affine prediction mode and an MMVD prediction mode.

[0094] The inter_pred_idc is a value indicating the type and number of reference pictures, and takes one of the values ​​PRED_L0, PRED_L1, and PRED_BI. PRED_L0 and PRED_L1 are managed by the L0 list and the L1 list, respectively. PRED_BI is managed by the L0 list and the L1 list. 1 shows bi-prediction using two reference pictures.

[0095] merge_idx is the prediction parameter candidate (merge candidate) derived from the processed block. (comment) is to be used as a prediction parameter for the current block.

[0096] (Motion Vector) mvLX indicates the amount of shift between blocks on two different pictures. A prediction vector and a difference vector related to mvLX are called mvpLX and mvdLX, respectively.

[0097] (Inter prediction identifier inter_pred_idc and prediction list usage flag predFlagLX) The relationship between inter_pred_idc, predFlagL0, and predFlagL1 is as follows, and they are mutually convertible.

[0098] inter_pred_idc = (predFlagL1<<1)+predFlagL0 predFlagL0 = inter_pred_idc & 1 predFlagL1 = inter_pred_idc >> 1 In addition, the inter prediction parameter may use a prediction list usage flag or an inter prediction identifier. Furthermore, the determination using the prediction list usage flag may be replaced with a determination using the inter prediction identifier. Conversely, the determination using the inter prediction identifier may be replaced with a determination using the prediction list usage flag.

[0099] (Bi-predictive biPred decision) The flag biPred indicating whether or not the prediction is performed can be derived based on whether or not two prediction list usage flags are both 1. For example, the flag can be derived by the following formula.

[0100] biPred = (predFlagL0==1 && predFlagL1==1) Alternatively, biPred can be derived based on whether the inter prediction identifier is a value indicating the use of two prediction lists (reference pictures). For example, biPred can be derived using the following formula:

[0101] biPred = (inter_pred_idc==PRED_BI) ? 1 : 0 (Configuration of an image decoding device) The configuration of an image decoding device 31 (FIG. 7) according to this embodiment will be described.

[0102] The image decoding device 31 includes an entropy decoding unit 301, a parameter decoding unit (prediction image decoding device) 302, a loop filter 305, a reference picture memory 306, a prediction parameter memory 307, and a prediction image A generation unit (prediction image generation device) 308, an inverse quantization and inverse transformation unit 311, an addition unit 312, a prediction parameter The image decoding device 320 is configured to include a data derivation unit 320. In some configurations, the device 31 does not include a loop filter 305 .

[0103] The parameter decoding unit 302 further includes a header decoding unit 3020, a CT information decoding unit 3021, and a CU decoding unit 3022. The CU decoding unit 3022 further includes a TU decoding unit 3024. These may be collectively referred to as a decoding module. The header decoding unit 3020 decodes parameter set information such as VPS, SPS, PPS, and APS, and slice headers (slice information) from the encoded data. The CT information decoding unit 3021 decodes the CT from the encoded data. The CU decoding unit 3022 decodes the CU from the encoded data. The TU decoding unit 3024 extracts QP update information (quantization correction value) and quantized prediction error (residual_coding) from the encoded data when a prediction error is included in the TU. Decrypt.

[0104] The TU decoding unit 3024 decodes the QP update information and the quantized prediction error from the encoded data when the mode is other than the skip mode (skip_mode==0). More specifically, when skip_mode==0, the TU decoding unit 3024 decodes the flag cu_cbp indicating whether or not the current block includes a quantized prediction error, and decodes the quantized prediction error when cu_cbp is 1. When cu_cbp does not exist in the encoded data, In this case, it is derived as 0.

[0105] The TU decoding unit 3024 decodes the index mts_idx indicating the transformation base from the encoded data. In addition, the TU decoding unit 3024 decodes an index stIdx indicating the use of a secondary transform and a transform base from the encoded data. When stIdx is 0, it indicates that a secondary transform is not applied, when it is 1, it indicates one of the transforms in a set (pair) of secondary transform bases, and when it is 2, it indicates that one of the above-mentioned pair is applied. The other transformation is shown below.

[0106] Furthermore, the TU decoding unit 3024 may decode a sub-block transform flag cu_sbt_flag. When cu_sbt_flag is 1, the CU is divided into a plurality of sub-blocks, and the residual of only one specific sub-block is decoded. Furthermore, the TU decoding unit 3024 may decode a flag cu_sbt_quad_flag indicating whether the number of sub-blocks is 4 or 2, cu_sbt_horizontal_flag indicating the division direction, and cu_sbt_pos_flag indicating a sub-block including a non-zero transform coefficient.

[0107] The predicted image generating unit 308 includes an inter predicted image generating unit 309 and an intra predicted image generating unit 310. It is composed of:

[0108] The prediction parameter derivation unit 320 is configured to include an inter prediction parameter derivation unit 303 and an intra prediction parameter derivation unit 304 .

[0109] In the following, we will describe an example in which CTU and CU are used as processing units, but this is not limiting. Alternatively, the processing may be performed in units of sub-CUs. and processing may be performed in units of blocks or sub-blocks.

[0110] The entropy decoding unit 301 performs entropy decoding on the encoded data Te input from the outside. The entropy decoder 301 performs decoding to decode each code (syntax element). There are two types of entropy coding: one is to perform variable-length coding of syntax elements using a context (probability model) adaptively selected according to the type of syntax element and surrounding circumstances, and the other is to perform variable-length coding of syntax elements using a predetermined table or formula. The former CABAC (Context Adaptive Binary Arithmetic Coding) stores the CABAC state of the context (probability state index pStateIdx that specifies the type (0 or 1) and probability of the most probable symbol) in memory. The entropy decoder 301 initializes all CABAC states at the beginning of a segment (tile, CTU row, slice). The entropy decoder 301 converts the syntax element into a binary string (Bin String) and decodes each bit of the Bin String. When a context is used, a context index ctxInc is derived for each bit of the syntax element, the bit is decoded using the context, and the CABAC state of the used context is updated. Bits without context are decoded with equal probability (EP, bypass), and ctxInc derivation and CABAC state are omitted. The decoded syntax elements include prediction information for generating a predicted image and prediction error for generating a difference image.

[0111] The entropy decoding unit 301 outputs the decoded code to the parameter decoding unit 302. The decoded code is, for example, a prediction mode predMode, merge_flag, merge_idx, inter_pred_idc, refIdxLX, mvp_LX_idx, mvdLX, amvr_mode, etc. Control of which code to decode is performed based on an instruction from the parameter decoding unit 302.

[0112] (Basic flow) FIG. 8 is a flowchart illustrating a schematic operation of the image decoding device 31.

[0113] (S1100: Decode Parameter Set Information) The header decoding unit 3020 decodes parameter set information such as the VPS, SPS, and PPS from the encoded data.

[0114] (S1200: Decode slice information) The header decoding unit 3020 decodes slice header information from the encoded data. Decode (slice information).

[0115] Hereinafter, the image decoding device 31 performs the steps S1300 to S5000 for each CTU included in the target picture. The process is repeated to derive a decoded image for each CTU.

[0116] (S1300: Decode CTU Information) The CT information decoding unit 3021 decodes the CTU from the encoded data.

[0117] (S1400: Decode CT Information) The CT information decoding unit 3021 decodes the CT from the encoded data.

[0118] (S1500: CU Decoding) The CU decoding unit 3022 performs S1510 and S1520 to decode the CU from the encoded data. Issued.

[0119] (S1510: Decode CU information) The CU decoding unit 3022 decodes CU information, prediction information, and TU division from the encoded data. The flag split_transform_flag, the CU residual flags cbf_cb, cbf_cr, cbf_luma, etc. are decoded.

[0120] (S1520: Decode TU information) When a TU includes a prediction error, the TU decoding unit 3024 decodes the encoded TU information. The QP update information, the quantization prediction error, and the transform index mts_idx are decoded from the data. Note that the QP update information is derived from the quantization parameter predicted value qPpred, which is the predicted value of the quantization parameter QP. This is the difference value.

[0121] (S2000: Generation of predicted image) The predicted image generation unit 308 generates a predicted image for each block included in the current CU based on the prediction information.

[0122] (S3000: Inverse Quantization and Inverse Transformation) The inverse quantization and inverse transform unit 311 executes inverse quantization and inverse transform processing for each TU included in the target CU.

[0123] (S4000: Decoded image generation) The adder 312 receives a predicted image from the predicted image generator 308 and The prediction error supplied from the inverse quantization and inverse transform unit 311 is added to the A decoded image is generated.

[0124] (S5000: Loop Filter) The loop filter 305 applies a loop filter such as a deblocking filter, SAO, or ALF to the decoded image to generate a decoded image.

[0125] (Configuration of inter-prediction parameter derivation unit) 9 is a schematic diagram showing the configuration of the inter-prediction parameter derivation unit 303 according to this embodiment. The inter-prediction parameter derivation unit 303 decodes prediction parameters stored in the prediction parameter memory 307 based on the syntax elements input from the parameter decoding unit 302. The inter prediction parameter derivation unit 303 and its internal element, the AMVP prediction parameter derivation unit 3032, the merge prediction parameter derivation unit 3033, and the merge prediction parameter derivation unit 3034 refer to the inter prediction parameter derivation unit 303 and output the inter prediction parameters to the inter prediction image generation unit 309 and the prediction parameter memory 307. Derivation unit 3036, affine prediction unit 30372, MMVD prediction unit 30373, GPM unit 30377, DMVR unit 30537, MV addition unit 3038 Since the calculation unit 3038 is a unit common to the image encoding device and the image decoding device, these may be collectively referred to as a motion vector derivation unit (motion vector derivation device).

[0126] The scale parameter derivation unit 30378 derives the horizontal scaling ratio RefPicScale[i][j][0] of the reference picture, the vertical scaling ratio RefPicScale[i][j][1] of the reference picture, and RefPicIsScaled[i][j] indicating whether the reference picture is scaled or not, where i indicates whether the reference picture list is the L0 list or the L1 list, and j is the value of the L0 reference picture list or the L1 reference picture y list, as follows:

[0127] RefPicScale[i][j][0] = ((fRefWidth << 14)+(PicOutputWidthL >> 1)) / PicOutputWidthL RefPicScale[ i ][ j ]

[0001] = ((fRefHeight << 14)+(PicOutputHeightL >> 1)) / PicOutputHeightL RefPicIsScaled[i][j] = (RefPicScale[i][j][0] != (1<<14)) || (RefPicScale[i][j][1] != (1<<14)) Here, the variable PicOutputWidthL is the horizontal scale when the coded picture is referenced. The variable PicOutputHeightL is a value used when calculating the scaling ratio, and is calculated by subtracting the left and right offset values ​​from the number of pixels in the horizontal direction of the luminance of the coded picture. The variable PicOutputHeightL is a value used when calculating the vertical scaling ratio when the coded picture is referenced, and is calculated by subtracting the top and bottom offset values ​​from the number of pixels in the vertical direction of the luminance of the coded picture. The variable fRefWidth Let fRefHight be the value of PicOutputWidthL of the reference picture with reference picture list value j in list i, and let variable fRefHight be the value of PicOutputHeightL of the reference picture with reference picture list value j in list i.

[0128] When affine_flag is 1, that is, when affine prediction mode is indicated, the affine prediction unit 30372 derives inter prediction parameters on a sub-block basis.

[0129] When mmvd_flag is 1, that is, when it indicates the MMVD prediction mode, the MMVD predictor 30373 derives inter prediction parameters from the merge candidates and difference vectors derived by the merge prediction parameter derivation unit 3036.

[0130] If gpm_flag is 1, ie, indicates Geometric Partitioning Mode, the GPM unit 30377 derives the GPM parameters.

[0131] If merge_flag is 1, i.e., it indicates merge prediction mode, derive merge_idx and The resultant signal is output to the prediction parameter derivation unit 3036.

[0132] When merge_flag is 0, that is, when it indicates the AMVP prediction mode, the AMVP prediction parameter derivation unit 3032 derives mvpLX from inter_pred_idc, refIdxLX, or mvp_LX_idx.

[0133] (MV addition section) The MV adder 3038 adds the derived mvpLX and mvdLX to derive mvLX.

[0134] (Affine prediction part) The affine prediction unit 30372 performs the following steps: 1) estimating two control points CP0 and CP1 of the target block, or estimating three control points CP1 and CP2 of the target block; 2) Derive the motion vectors of the control points CP0, CP1, and CP2, and 3) derive the affine prediction parameters of the target block. 3) derive a motion vector for each subblock from the affine prediction parameters.

[0135] (Merge prediction) 10 is a schematic diagram showing the configuration of the merge prediction parameter derivation unit 3036 according to this embodiment. The merge prediction parameter derivation unit 3036 includes a merge candidate derivation unit 30361, a merge candidate The merging candidate list includes a selection unit 30362. The merging candidates are configured to include prediction parameters (predFlagLX, mvLX, refIdxLX) and are stored in a merging candidate list. An index is assigned to the merging candidates stored in the merging candidate list according to a predetermined rule.

[0136] The merge candidate derivation unit 30361 directly extracts the motion vector and refIdxLX of the decoded adjacent block. In addition, the merging candidate derivation unit 30361 uses the spatial Merge candidate derivation processes, temporal merge candidate derivation processes, pairwise merge candidate derivation processes, and zero merge candidate derivation processes may be applied.

[0137] (DMVR) Next, a description will be given of a DMVR (Decoder side Motion Vector Refinement) process performed by the DMVR unit 30375. The DMVR unit 30375 performs the DMVR process when the merge_flag is 1 or the skipped CU is not yet determined to be a target CU. When the flag skip_flag is 1, the mvLX of the target CU derived by the merge prediction unit 30374 is Specifically, the prediction parameters derived by the merge prediction unit 30374 are bi-predictive. When the motion vector is estimated, the motion vector is corrected using a predicted image derived from the motion vector corresponding to two reference pictures. The corrected mvLX is output to the inter-prediction image generating unit 309. are supplied to.

[0138] (AMVP Prediction) 10 is a schematic diagram showing the configuration of the AMVP prediction parameter derivation unit 3032 according to this embodiment. The AMVP prediction parameter derivation unit 3032 includes a vector candidate derivation unit 3033 and a vector candidate selection unit 3034. The vector candidate derivation unit 3033 derives a prediction vector candidate from the motion vector of the decoded adjacent block stored in the prediction parameter memory 307 based on refIdxLX. , and stored in the predicted vector candidate list mvpListLX[ ].

[0139] The vector candidate selection unit 3034 selects the predicted vector candidate mvp_LX_idx from among the predicted vector candidates in mvpListLX[]. The vector candidate selection unit 3034 outputs the selected mvpLX to the MV addition unit 3038.

[0140] (MV addition section) The MV addition unit 3038 calculates mvLX by adding the mvpLX input from the AMVP prediction parameter derivation unit 3032 and the decoded mvdLX. The addition unit 3038 outputs the calculated mvLX to the inter predicted image generation unit 309. and outputs it to the prediction parameter memory 307.

[0141] mvLX[0] = mvpLX[0] + mvdLX[0] mvLX[1] = mvpLX[1] + mvdLX[1] (Detailed classification of subblock merges) The types of prediction processes related to sub-block merging are summarized below. As described above, they are roughly divided into merge prediction and AMVP prediction.

[0142] Merge predictions are further categorized as follows:

[0143] Normal merge prediction (block-based merge prediction) Sub-block merge prediction Sub-block merge prediction is further categorized as follows:

[0144] Sub-block prediction (ATMVP) Affine prediction Inferred affine prediction · Constructed affine prediction On the other hand, AMVP predictions are categorized as follows:

[0145] ·AMVP (translation) ·MVD affine prediction MVD affine prediction is further categorized as follows:

[0146] 4-parameter MVD affine prediction 6-parameter MVD affine prediction It should be noted that MVD affine prediction refers to affine prediction that uses a decoded difference vector.

[0147] In subblock prediction, similar to the temporal merge derivation process, the availability of the collocated subblock COL of the target subblock is determined. If it is available, the prediction parameters are At least when the above-mentioned SliceTemporalMvpEnabledFlag is 0, availableFlagSbCol is set to 0.

[0148] MMVD prediction (Merge with Motion Vector Difference) can be classified as merge prediction. , or AMVP prediction. In the former case, mmvd_flag and MMVD related Decode the syntax elements, and in the latter, if merge_flag=0, mmvd_flag and MMVD related syntax elements are Decode the tax element.

[0149] The loop filter 305 is a filter provided in the coding loop, and is used to remove block distortion and ringing. The loop filter 305 is a filter that removes distortion and improves image quality. The loop filter 305 applies a deblocking filter, a sample adaptive offset (SAO), and an adaptive filter to the decoded image of the CU generated by the adder 312. Apply a filter such as an automatic loop filter (ALF).

[0150] The reference picture memory 306 stores the decoded image of the CU in a predetermined Store it in position.

[0151] The prediction parameter memory 307 stores prediction parameters at a predetermined location for each CTU or CU. Specifically, the prediction parameter memory 307 stores parameters decoded by the parameter decoding unit 302, parameters derived by the prediction parameter derivation unit 320, and the like.

[0152] The predicted image generation unit 308 receives the parameters derived by the prediction parameter derivation unit 320. The predicted image generation unit 308 also reads a reference picture from the reference picture memory 306. The predicted image generation unit 308 generates a prediction image based on the parameters and the reference picture (reference picture A reference picture block (a reference block) is used to generate a predicted image of a block or sub-block. Here, a reference picture block is a set of pixels on a reference picture (usually rectangular, so called a block), and is an area to be referenced in order to generate a predicted image.

[0153] (Inter-prediction image generation unit 309) When predMode indicates an inter prediction mode, the inter prediction image generating unit 309 Using the inter-prediction parameters and the reference pictures input from the prediction parameter derivation unit 303, A predicted image of the block or sub-block is generated by inter prediction.

[0154] FIG. 11 is a schematic diagram showing a configuration of an inter-prediction image generating unit 309 included in the prediction image generating unit 308 according to this embodiment. The inter-prediction image generating unit 309 is a motion compensation unit (prediction image generating device). The synthesis unit 3095 includes an IntraInter synthesis unit 30951, a GPM synthesis unit 30952, a BDOF unit 30954, and a weighted prediction unit 3094.

[0155] (Motion Compensation) The motion compensation unit 3091 (interpolated image generation unit 3091) receives the input from the inter prediction parameter derivation unit 303. Based on the input inter prediction parameters (predFlagLX, refIdxLX, mvLX), an interpolated image (motion compensated image) is generated by reading a reference block from the reference picture memory 306. The reference block is a block shifted by mvLX from the position of the target block on the reference picture RefPicLX specified by refIdxLX. If mvLX does not have integer precision, an interpolated image is generated by applying a filter called a motion compensation filter for generating pixels at decimal positions.

[0156] The motion compensation unit 3091 first derives an integer position (xInt, yInt) and a phase (xFrac, yFrac) corresponding to coordinates (x, y) in the prediction block using the following formula.

[0157] xInt = xPb+(mvLX[0]>>(log2(MVPREC)))+x xFrac = mvLX[0]&(MVPREC-1) yInt = yPb+(mvLX[1]>>(log2(MVPREC)))+y yFrac = mvLX[1]&(MVPREC-1) Here, (xPb, yPb) are the upper left coordinates of a block of size bW*bH, where x=0...bW-1, y=0...bH-1, and MVPREC indicates the accuracy of mvLX (1 / MVPREC pixel accuracy), e.g., MVPREC=16.

[0158] The motion compensation unit 3091 derives a temporary image temp[][] by performing horizontal interpolation processing on the reference picture refImg using an interpolation filter. In the following, Σ is the sum for k=0..NTAP-1, shift1 is a normalization parameter that adjusts the value range, and offset1=1<<(shift1-1).

[0159] temp[x][y] = (ΣmcFilter[xFrac][k]*refImg[xInt+k-NTAP / 2+1][yInt]+offset1)>>shift1 Next, the motion compensation unit 3091 derives the interpolated image Pred[][] by vertically interpolating the temporary image temp[][]. In the following, Σ is the sum for k=0..NTAP-1, shift2 is a normalization parameter that adjusts the value range, and offset2=1<<(shift2-1).

[0160] Pred[x][y] = (ΣmcFilter[yFrac][k]*temp[x][y+k-NTAP / 2+1]+offset2)>>shift2 In the case of bi-prediction, the above Pred[][] is derived for each L0 list and L1 list (called interpolated images PredL0[][] and PredL1[][]), and an interpolated image Pred[][] is generated from PredL0[][] and PredL1[][].

[0161] The motion compensation unit 3091 uses the reference picture derived by the scale parameter derivation unit 30378. The interpolation unit 102 has a function of scaling the interpolated image according to the horizontal scaling ratio RefPicScale[i][j][0] of the reference picture 102 and the vertical scaling ratio RefPicScale[i][j][1] of the reference picture 102.

[0162] The synthesis unit 3095 includes an IntraInter synthesis unit 30951, a GPM synthesis unit 30952, a weighted prediction unit 3094, and a BDOF unit 30954.

[0163] (IntraInter synthesis processing) The IntraInter synthesis unit 30951 synthesizes the inter-predicted image and the intra-predicted image by weighting the sum of the inter-predicted image and the intra-predicted image. A predicted image is generated.

[0164] The pixel value predSamplesComb[x][y] of the predicted image indicates whether to apply IntraInter synthesis processing. If the flag ciip_flag is 1, it is derived as follows:

[0165] predSamplesComb[x][y] =(w * predSamplesIntra[x][y] +(4 - w)*predSamplesInter[x][y] + 2)>> 2 Here, predSamplesIntra[x][y] is the intra-predicted image, which is restricted to planar prediction, and predSamplesInter[x][y] is the reconstructed inter-predicted image.

[0166] The weight w is derived as follows:

[0167] The bottommost block adjacent to the left of the target coding block (A1 in FIG. 9) and the rightmost block adjacent to the top If both blocks (B1 in FIG. 9) are intra, then w is set to 3.

[0168] Otherwise, if both the bottommost left-neighboring block and the rightmost upper-neighboring block to the current coding block are not intra, then w is set to 1.

[0169] Otherwise, w is set to 2.

[0170] (GPM synthesis processing) The GPM synthesis unit 30952 generates a predicted image using the above-mentioned GPM.

[0171] (BDOF prediction) Next, a description will be given of BDOF prediction (Bi-Directional Optical Flow, BDOF processing) performed by the BDOF unit 30954. In a bi-prediction mode, the BDOF unit 30954 performs two predicted images (a first predicted image and A predicted image is generated by referring to the first predicted image (and the second predicted image) and the gradient correction term.

[0172] (Weighted prediction) The weighted prediction unit 3094 performs weighted prediction from the interpolated image PredLX to generate a predicted image pbSamples Generate.

[0173] When predMode indicates an intra prediction mode, the intra prediction image generation unit 310 The intra prediction unit 303 performs intra prediction using the intra prediction parameters input from the prediction parameter derivation unit 304 and reference pixels read from the reference picture memory 306 .

[0174] The inverse quantization and inverse transform unit 311 inverse quantizes the quantized transform coefficients input from the parameter decoding unit 302 to obtain transform coefficients.

[0175] The adder 312 adds, for each pixel, the predicted image of the block input from the predicted image generation unit 308 and the prediction error input from the inverse quantization and inverse transform unit 311 to generate a decoded image of the block. The adder 312 stores the decoded image of the block in the reference picture memory 306 , and also outputs it to the loop filter 305 .

[0176] The inverse quantization and inverse transform unit 311 inverse quantizes the quantized transform coefficients input from the parameter decoding unit 302 to obtain transform coefficients.

[0177] The adder 312 adds, for each pixel, the predicted image of the block input from the predicted image generation unit 308 and the prediction error input from the inverse quantization and inverse transform unit 311 to generate a decoded image of the block. The adder 312 stores the decoded image of the block in the reference picture memory 306 , and also outputs it to the loop filter 305 .

[0178] (Configuration of Image Encoding Device) Next, the configuration of the image encoding device 11 according to this embodiment will be described. Fig. 12 is a block diagram showing the configuration of the image encoding device 11 according to this embodiment. The image encoding device 11 includes a predicted image generating unit 101, a subtraction unit 102, a transform / quantization unit 103, an inverse quantization / inverse transform unit 105, an addition unit 106, a rule The image processing system includes a loop filter 107, a prediction parameter memory (prediction parameter storage unit, frame memory) 108, a reference picture memory (reference image storage unit, frame memory) 109, an encoding parameter determination unit 110, a parameter encoding unit 111, a prediction parameter derivation unit 120, and an entropy encoding unit 104.

[0179] The predicted image generation unit 101 generates a predicted image for each CU. The predicted image generation unit 101 includes the inter predicted image generation unit 309 and the intra predicted image generation unit 310, which have already been described, and therefore a description thereof will be omitted.

[0180] The subtraction unit 102 generates a prediction error by subtracting the pixel values ​​of the predicted image of the block input from the predicted image generation unit 101 from the pixel values ​​of the image T. The subtraction unit 102 outputs the prediction error to the transformation and quantization unit 103.

[0181] The transform / quantization unit 103 performs frequency transform on the prediction error input from the subtraction unit 102. The transform / quantization unit 103 calculates transform coefficients and derives quantized transform coefficients by quantization. The quantized transform coefficients are output to the parameter coding unit 111 and the inverse quantization and inverse transform unit 105 .

[0182] The inverse quantization and inverse transform unit 105 corresponds to the inverse quantization and inverse transform unit 311 (FIG. 7) in the image decoding device 31. The calculated prediction error is output to the adder 106.

[0183] The parameter coding unit 111 includes a header coding unit 1110, a CT information coding unit 1111, and a CU coding unit 1112 (prediction mode coding unit). The CU coding unit 1112 further includes a TU coding unit 1114. The following describes an outline of the operation of each module.

[0184] The header encoding unit 1110 performs encoding processing of parameters such as header information, division information, prediction information, and quantized transform coefficients.

[0185] The CT information encoding unit 1111 encodes the QT, MT (BT, TT) division information and the like.

[0186] The CU encoding unit 1112 encodes the CU information, prediction information, division information, and so on.

[0187] When a prediction error is included in a TU, the TU encoding unit 1114 encodes the QP update information and the quantized prediction error.

[0188] The CT information encoding unit 1111 and the CU encoding unit 1112 supply syntax elements such as inter prediction parameters (predMode, merge_flag, merge_idx, inter_pred_idc, refIdxLX, mvp_LX_idx, mvdLX), intra prediction parameters (intra_luma_mpm_flag, intra_luma_mpm_idx, intra_luma_mpm_reminder, intra_chroma_pred_mode), and quantized transform coefficients to the parameter encoding unit 111.

[0189] The entropy coding unit 104 receives the quantized transform coefficients and coding parameters (division information, prediction parameters) from the parameter coding unit 111. These are then entropy-encoded to generate encoded data Te, which is then output.

[0190] The prediction parameter derivation unit 120 is a means including an inter-prediction parameter encoding unit 112 and an intra-prediction parameter encoding unit 113, and derives intra-prediction parameters and intra-prediction parameters from the parameters input from the encoding parameter determination unit 110. The derived intra-prediction parameters and intra-prediction parameters are output to the parameter encoding unit 111.

[0191] (Configuration of the inter-prediction parameter encoding unit) 13, the inter prediction parameter encoding unit 112 includes a parameter encoding control unit 1121 and an inter prediction parameter derivation unit 303. The inter prediction parameter derivation unit 303 has the same configuration as the image decoding device. The parameter encoding control unit 1121 includes a merge index derivation unit 11211 and a vector candidate index derivation unit 11212.

[0192] The merge index derivation unit 11211 derives merge candidates and the like, and calculates inter prediction parameters The vector candidate index derivation unit 11212 derives predicted vector candidates and the like, and outputs them to the inter prediction parameter derivation unit 303 and the parameter coding unit 111.

[0193] (Configuration of the intra-prediction parameter encoding unit 113) The intra-prediction parameter coding unit 113 is a parameter coding control unit 1131 and an intra-prediction The image decoding device includes a parameter derivation unit 304. The intra prediction parameter derivation unit 304 has the same configuration as the image decoding device.

[0194] The parameter coding control unit 1131 derives IntraPredModeY and IntraPredModeC. Furthermore, it determines intra_luma_mpm_flag by referring to mpmCandList[ ]. These prediction parameters are output to the intra prediction parameter derivation unit 304 and the parameter coding unit 111.

[0195] However, unlike the image decoding device, the inter prediction parameter derivation unit 303 and the intra prediction parameter derivation unit 304 are The input to the parameter derivation unit 304 is the coding parameter determination unit 110 and the prediction parameter memory 108. and outputs it to parameter coding section 111.

[0196] The adder 106 generates a decoded image by adding, for each pixel, the pixel value of the predicted block input from the predicted image generation unit 101 and the prediction error input from the inverse quantization and inverse transform unit 105. The adder 106 stores the generated decoded image in a reference picture memory 109.

[0197] The loop filter 107 performs deblocking filtering, SAO, and ALF on the decoded image generated by the adder 106. Note that the loop filter 107 does not necessarily include the above three types of filters. For example, the filter may be configured with only a deblocking filter.

[0198] The prediction parameter memory 108 stores the prediction parameters generated by the coding parameter determination unit 110 in a predetermined location for each current picture and CU.

[0199] The reference picture memory 109 stores the decoded image generated by the loop filter 107 at a predetermined position for each current picture and CU.

[0200] The encoding parameter determination unit 110 determines one of the multiple sets of encoding parameters. The coding parameters are the above-mentioned QT, BT or TT division information, prediction parameters, or parameters to be coded that are generated in relation to these. The predicted image generating unit 101 generates a predicted image using these coding parameters.

[0201] The coding parameter determination unit 110 determines the size of the amount of information and the coding parameter for each of the plurality of sets. The RD cost value indicating the error is calculated. The RD cost value is, for example, the sum of the code amount and the value obtained by multiplying the squared error by a coefficient λ. The code amount is the information amount of the coded data Te obtained by entropy coding the quantization error and the coding parameters. The squared error is calculated in the subtraction unit 102. The coefficient λ is a preset real number greater than zero. The coding parameter determination unit 110 determines a set of coding parameters that minimizes the calculated cost value. The encoding parameter determination unit 110 selects the determined encoding parameters as a parameter code. The resultant signal is output to the image forming unit 111 and the prediction parameter derivation unit 120.

[0202] In addition, a part of the image encoding device 11 and the image decoding device 31 in the above-mentioned embodiment, for example, the entropy decoding unit 301, the parameter decoding unit 302, the loop filter 305, the predicted image generating unit 308, the inverse quantization and inverse transform unit 311, the addition unit 312, the prediction parameter derivation unit 320, the predicted image generating unit 101, the subtraction unit 102, the transform and quantization unit 103, the entropy coding unit 104, the inverse quantization and inverse transform unit 105, the loop filter 107, the coding parameter determination unit 110, the parameter coding unit 111, and the prediction parameter derivation unit 120 may be realized by a computer. In this case, a program for realizing this control function may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into and executed by a computer system. In addition, the "computer system" referred to here is a computer system built into either the image encoding device 11 or the image decoding device 31, and includes hardware such as an OS and peripheral devices. In addition, "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording medium" may also include devices that dynamically hold a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, and devices that hold a program for a certain period of time, such as volatile memory inside a computer system that serves as a server or client in such cases. Furthermore, the above program may be one that realizes part of the above-mentioned functions, or may be one that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

[0203] In addition, a part or the whole of the image encoding device 11 and the image decoding device 31 in the above-mentioned embodiment may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each functional block of the image encoding device 11 and the image decoding device 31 may be individually made into a processor, or a part or the whole may be integrated into a processor. The integrated circuit method is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to the progress of semiconductor technology, an integrated circuit based on that technology may be used.

[0204] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes, etc. are possible within the scope that does not deviate from the gist of the present invention.

[0205] (SEI for resolution inversion) FIG. 16 shows an example of the syntax of SEI for the resolution inverse conversion process in this embodiment. 16 is a diagram showing an example of a resolution inverse conversion process. As shown in Fig. 16, the following syntax elements may be included. Parameters including the following syntax elements used in the resolution inverse conversion process are called inverse conversion information. nnr_level_idc: Syntax element for deriving level information for resolution inversion processing The level NNR_level of the inverse transform process using the neural network is derived according to the table in FIG. ·nnr_parameter_scale: Syntax for deriving level information for resolution inversion processing This element indicates the scaling value of the network parameters. It is used to derive NNR_Complexity, which indicates the complexity of the resolution inverse conversion process described above. Note that nnr_parameter_scale is Specifically, it is used to adjust the number of bytes used as the unit of calculation for network parameters, the pixel bit length of input / output, and the complexity due to differences in image format.

[0206] Here, payloadSize is a number representing the number of bytes of SEI data.

[0207] The neural network used in the inverse conversion process is encoded as a parameter representation of the neural network in a standard format such as ONNX (Open Neural Network eXchange), NNEF (Neural Network Exchange Format), MPEG NNR (Moving Picture Experts Group Neural Network Representation), or a format dependent on a library such as tensorflow or pytorch. Separately, the parameter representation is multiplexed into SEI or system information as proposed in Non-Patent Document 2, and shared with the resolution inverse conversion device.

[0208] FIG. 17 is another example of the syntax of the SEI for the resolution inverse conversion process in this embodiment. In Fig. 17, in addition to the syntax elements in Fig. 16, data obtained by encoding a neural network used in the inverse conversion process is added. The above-mentioned method is used as the encoding method. nnr_payload_byte: The value in bytes of the coded data of the neural network used in the resolution inverse conversion process. The length of the coded data is (payloadSize-2) bytes.

[0209] The level information specified by the syntax allows the complexity of the resolution inverse conversion process to be known, so that it can be guaranteed that the process can be executed at an appropriate speed.

[0210] Furthermore, in the present embodiment, the resolution inverse conversion process has been described, but the present invention may be applied simply as image restoration process as a post-filter without changing the resolution.

[0211] In order to support multiple formats as the transmission format of the inverse conversion information, a parameter (identifier) ​​indicating the format may be sent. Also, the actual inverse conversion information following the identifier may be transmitted as a byte string.

[0212] (APS for resolution inverse conversion processing) Fig. 18 is a diagram showing an example of syntax obtained by extending the APS (Adaptive Parameter Set) for resolution inverse conversion processing in this embodiment. As shown in Fig. 18, the following syntax elements may be included. aps_extension_flag: A flag indicating that there is APS extension data. If aps_extension_flag is 1, nnr_extension_flag is encoded. If aps_extension_flag is 0, Since no APS extension data is present, nnr_extension_flag is not coded and is assumed to be 0. nnr_extension_flag: A flag indicating the presence of level information for resolution inverse conversion processing. This is also a flag indicating whether or not to code and decode the syntax of nnr_extension_data(). If nnr_extension_flag is 1, the syntax of nnr_extension_data() is coded and decoded. nnr_extension_data() is a syntax that includes resolution inverse conversion information.

[0213] Figure 19 shows an example of the syntax of nnr_extension_data(), which is one of the extension information of APS. nnr_extension_data() contains level information used for the resolution inverse conversion process. nnr_level_idc: Syntax element for deriving level information for resolution inversion processing The level NNR_level of the inverse transform process using the neural network is derived according to the table in FIG. ·nnr_parameter_scale: Syntax for deriving level information for resolution inversion processing As an element, it is coded and decoded as a scaling value of the network parameters. Then, as a syntax element of the level information, it is used to derive NNR_Complexity, which indicates the complexity of the above-mentioned resolution inverse conversion process. Specifically, nnr_parameter_scale is used to adjust the number of bytes of the unit of calculation of the network parameters, the pixel bit length of input and output, and the complexity due to differences in image format. nnr_payload_byte: The value in bytes of the coded data of the neural network used for the resolution inverse conversion process. The length of the coded data is (payloadSize-2) bytes.

[0214] When performing resolution inverse conversion processing, knowing the complexity of the processing can ensure that it can be performed properly.

[0215] In this embodiment, the resolution inverse conversion process has been described, but the extended syntax of APS may be applied simply to image restoration process as a post filter or to an in-loop filter.

[0216] It can also be used as an interpolation filter in motion compensated prediction.

[0217] [Application example] The above-mentioned video encoding device 10 and video decoding device 30 can be mounted and used in various devices that transmit, receive, record, and play back video. The video may be a natural video captured by a camera or the like, or an artificial video (CG) generated by a computer or the like. and GUI).

[0218] First, it will be described with reference to FIG. 2 that the above-mentioned video encoding device 10 and video decoding device 30 can be used for transmitting and receiving videos.

[0219] PROD_A in FIG. 2 is a block diagram showing the configuration of a transmission device PROD_A equipped with a video encoding device 10. As shown in the figure, the transmitting device PROD_A includes an encoding unit PROD_A1 that obtains encoded data by encoding a moving image, a modulation unit PROD_A2 that obtains a modulated signal by modulating a carrier wave with the encoded data obtained by the encoding unit PROD_A1, and a transmitting unit PROD_A3 that transmits the modulated signal obtained by the modulation unit PROD_A2. The above-mentioned moving image encoding device 10 is used as this encoding unit PROD_A1.

[0220] The transmission device PROD_A captures moving images as a supply source of moving images to be input to the encoding unit PROD_A1. The apparatus further includes a camera PROD_A4 for recording moving images, a recording medium PROD_A5 for recording moving images, an input terminal PROD_A6 for inputting moving images from the outside, and an image processing unit A7 for generating or processing images. In the figure, a configuration in which the transmitting device PROD_A includes all of these components is illustrated, but some of them may be omitted.

[0221] The recording medium PROD_A5 may be one in which unencoded moving images are recorded. Alternatively, the recording medium PROD_A5 may be a recording medium that has recorded thereon a video encoded by a recording encoding method different from the transmission encoding method. In the latter case, a decoding unit ( It is advisable to use a conductor (not shown) between the two.

[0222] PROD_B in FIG. 2 is a block diagram showing the configuration of a receiving device PROD_B equipped with a video decoding device 30. As shown in the figure, the receiving device PROD_B includes a receiving unit PROD_B1 for receiving a modulated signal, The video decoding device 30 includes a demodulation unit PROD_B2 that obtains coded data by demodulating the modulated signal received by the receiving unit PROD_B1, and a decoding unit PROD_B3 that obtains a video by decoding the coded data obtained by the demodulation unit PROD_B2. The video decoding device 30 described above is used as the decoding unit PROD_B3.

[0223] The receiving device PROD_B is a supply destination of the video output by the decoding unit PROD_B3, and displays the video. The display PROD_B4 may further include a recording medium PROD_B5 for recording moving images, and an output terminal PROD_B6 for outputting the moving images to the outside. Although the receiving device PROD_B is illustrated as having the above configuration, some of these may be omitted.

[0224] The recording medium PROD_B5 is for recording unencoded moving images. Alternatively, the signal may be encoded by a coding method for recording that is different from the coding method for transmission. In the latter case, a signal from the decoding unit PROD_B3 to the recording medium PROD_B5 may be provided between the decoding unit PROD_B3 and the recording medium PROD_B5. It is preferable to interpose an encoding unit (not shown) that encodes the acquired video image according to an encoding method for recording.

[0225] The transmission medium for transmitting the modulated signal may be wireless or wired. The transmission mode for transmitting the modulated signal may be broadcast (here, this refers to a transmission mode in which the destination is not specified in advance) or communication (here, this refers to a transmission mode in which the destination is specified in advance). In other words, the transmission of the modulated signal may be realized by any of wireless broadcast, wired broadcast, wireless communication, and wired communication.

[0226] For example, a broadcasting station (such as a broadcasting facility) / receiving station (such as a television receiver) for terrestrial digital broadcasting is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives modulated signals by wireless broadcasting. Moreover, a cable television broadcasting station (broadcasting equipment, etc.) / receiving station (television receiver, etc.) is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives modulated signals by cable broadcasting.

[0227] Also, a server (such as a workstation) / client (such as a television receiver, a personal computer, a smartphone, etc.) of a VOD (Video On Demand) service or a video sharing service using the Internet is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives modulated signals by communication (usually, in a LAN, either wireless or wired is used as a transmission medium, and in a WAN, wired is used as a transmission medium). Here, personal computers include desktop PCs, laptop PCs, and tablet PCs. Also, smartphones include multi-function mobile phone terminals.

[0228] The client of the video hosting service has a function to decode the encoded data downloaded from the server and display it on a display, as well as a function to encode the video captured by the camera and upload it to the server. That is, the client of the video hosting service functions as both the transmitting device PROD_A and the receiving device PROD_B.

[0229] Next, it will be described with reference to FIG. 3 that the above-mentioned video encoding device 10 and video decoding device 30 can be used for recording and reproducing videos.

[0230] PROD_C in FIG. 3 shows the configuration of a recording device PROD_C equipped with the above-mentioned video encoding device 10. As shown in the figure, the recording device PROD_C includes an encoding unit PROD_C1 that obtains encoded data by encoding a moving image, and a writing unit PROD_C2 that writes the encoded data obtained by the encoding unit PROD_C1 onto a recording medium PROD_M. The above-mentioned moving image encoding device 10 is used as this encoding unit PROD_C1.

[0231] The recording medium PROD_M may be (1) a type built into the recording device PROD_C, such as an HDD (Hard Disk Drive) or SSD (Solid State Drive), (2) a type connected to the recording device PROD_C, such as an SD memory card or USB (Universal Serial Bus) flash memory, or (3) a type loaded into a drive device (not shown) built into the recording device PROD_C, such as a DVD (Digital Versatile Disc: registered trademark) or BD (Blu-ray Disc: registered trademark).

[0232] The recording device PROD_C supplies a video image to the encoding unit PROD_C1. The recording device PROD_C may further include a camera PROD_C3 for capturing an image, an input terminal PROD_C4 for inputting a moving image from the outside, a receiving unit PROD_C5 for receiving the moving image, and an image processing unit PROD_C6 for generating or processing an image. In the figure, the recording device PROD_C is illustrated as having all of these components, but some of them may be omitted.

[0233] The receiving unit PROD_C5 may receive uncoded video. Alternatively, the receiving unit PROD_C5 may receive encoded data that has been encoded by a transmission encoding method different from the recording encoding method. In the latter case, a transmission decoding unit (not shown) that decodes the encoded data that has been encoded by the transmission encoding method may be provided between the receiving unit PROD_C5 and the encoding unit PROD_C1.

[0234] Examples of such a recording device PROD_C include a DVD recorder, a BD recorder, and an HDD (Hard Disk Drive) recorder (in this case, the input terminal PROD_C4 or the receiving unit PROD_C5 is the main source of the moving image). Other examples of such a recording device PROD_C include a camcorder (in this case, the camera PROD_C3 is the main source of the moving image), a personal computer (in this case, the receiving unit PROD_C5 or the image processing unit C6 is the main source of the moving image), and a smartphone (in this case, the camera PROD_C3 or the receiving unit PROD_C5 is the main source of the moving image).

[0235] FIG. 3PROD_D is a block diagram showing the configuration of a playback device PROD_D incorporating the above-described video decoding device 30. As shown in the figure, the playback device PROD_D includes a reading unit PROD_D1 that reads out coded data written on a recording medium PROD_M, and a decoding unit PROD_D2 that obtains a video by decoding the coded data read out by the reading unit PROD_D1. The video decoding device 30 described above is used as this decoding unit PROD_D2.

[0236] The recording medium PROD_M may be (1) a type built into the playback device PROD_D, such as an HDD or SSD, or (2) a type of storage device, such as an SD memory card or a USB flash memory. (3) DVD, BD, etc. The DVD-ROM 10 may be loaded into a drive device (not shown) built into the playback device PROD_D.

[0237] In addition, the playback device PROD_D receives the video output from the decoding unit PROD_D2 and outputs the video to the playback device PROD_D. The apparatus may further include a display PROD_D3 for displaying the moving image, an output terminal PROD_D4 for outputting the moving image to the outside, and a transmission unit PROD_D5 for transmitting the moving image. Although the configuration of the playback device PROD_D is illustrated, some of the configuration may be omitted.

[0238] The transmission unit PROD_D5 may transmit uncoded video. Alternatively, the decoder unit PROD_D2 may transmit encoded data encoded by a transmission encoding method different from the recording encoding method. In the latter case, it is preferable to interpose an encoding unit (not shown) between the decoder unit PROD_D2 and the transmitter unit PROD_D5, which encodes the video image by the transmission encoding method.

[0239] Examples of such a playback device PROD_D include a DVD player, a BD player, and a HDD player (in this case, the output terminal PROD_D4 to which a television receiver or the like is connected operates). In this case, the display PROD_D3 or the transmitting unit PROD_D5 is the main destination of the moving images. Other examples of the playback device PROD_D include a television receiver (in this case, the display PROD_D3 is the main destination of the moving images), a digital signage (also called an electronic billboard or an electronic bulletin board, and the display PROD_D3 or the transmitting unit PROD_D5 is the main destination of the moving images), a desktop PC (in this case, the output terminal PROD_D4 or the transmitting unit PROD_D5 is the main destination of the moving images), a laptop or tablet PC (in this case, the display PROD_D3 or the transmitting unit PROD_D5 is the main destination of the moving images), and a smartphone (in this case, the display PROD_D3 or the transmitting unit PROD_D5 is the main destination of the moving images).

[0240] (Hardware and Software Realizations) Furthermore, each block of the above-mentioned video decoding device 30 and video encoding device 10 may be realized in hardware by a logic circuit formed on an integrated circuit (IC chip), or may be realized by a CPU. This may be realized in software using a Central Processing Unit (Central Processing Unit).

[0241] In the latter case, each of the above devices includes a CPU that executes the instructions of a program that realizes each function, ROM (Read Only Memory) stores the program, and RAM (Random Access Memory) expands the program. The present invention also includes a storage device (recording medium) such as a memory for storing the above-mentioned programs and various data, and the like. The object of the embodiment of the present invention can also be achieved by supplying each of the above-mentioned devices with a recording medium on which the program code (executable program, intermediate code program, source program) of the control program of each of the above-mentioned devices, which is software for realizing the above-mentioned functions, is recorded in a computer-readable manner, and the computer (or CPU or MPU) reads out and executes the program code recorded on the recording medium.

[0242] Examples of the recording medium that can be used include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy disks (registered trademark) and hard disks, disks including optical disks such as CD-ROMs (Compact Disc Read-Only Memory), MO disks (Magneto-Optical discs), MDs (Mini Discs), DVDs (Digital Versatile Discs: registered trademark), CD-Rs (CD Recordable), and Blu-ray Discs (registered trademark), cards such as IC cards (including memory cards) and optical cards, semiconductor memories such as mask ROMs, EPROMs (Erasable Programmable Read-Only Memory), EEPROMs (Electrically Erasable and Programmable Read-Only Memory: registered trademark), and flash ROMs, and logic circuits such as PLDs (Programmable logic devices) and FPGAs (Field Programmable Gate Arrays).

[0243] Moreover, each of the above devices may be configured to be connectable to a communication network, and the above program code may be supplied via the communication network. This communication network is not particularly limited as long as it is capable of transmitting the program code. For example, the Internet, an intranet, an extranet, a LAN (Local Area Network), an ISDN (Integrated Services Digital Network), a VAN (Value-Added Network), a CATV (Community Antenna television / Cable Television) communication network, a virtual private network, a telephone line network, a mobile communication network, a satellite communication network, etc. may be used. Moreover, the transmission medium constituting this communication network is not limited to a specific configuration or type as long as it is a medium capable of transmitting the program code. For example, it can be used in wired communication such as IEEE (Institute of Electrical and Electronic Engineers) 1394, USB, power line carrier, cable TV line, telephone line, ADSL (Asymmetric Digital Subscriber Line) line, etc., or in wireless communication such as infrared such as IrDA (Infrared Data Association) or remote control, BlueTooth (registered trademark), IEEE802.11 wireless, HDR (High Data Rate), NFC (Near Field Communication), DLNA (Digital Living Network Alliance: registered trademark), mobile phone network, satellite line, terrestrial digital broadcasting network, etc. The embodiment of the present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

[0244] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. In other words, the technical scope of the present invention also includes embodiments obtained by combining technical means that are appropriately modified within the scope of the claims. [Industrial Applicability]

[0245] The embodiments of the present invention can be suitably applied to a video decoding device that decodes coded data in which image data is coded, and a video coding device that generates coded data in which image data is coded, and can also be suitably applied to the data structure of coded data that is generated by a video coding device and referenced by the video decoding device. [Explanation of symbols]

[0246] 1. Video transmission system 30 Video Decoding Device 31 Image Decoding Device 301 Entropy Decoding Unit 302 Parameter Decoding Unit 303 Inter-prediction parameter derivation unit 304 Intra prediction parameter derivation unit 305, 107 Loop Filter 306, 109 Reference Picture Memory 307, 108 Prediction parameter memory 308, 101 Prediction image generation unit 309 Inter-prediction image generation unit 310 Intra-prediction image generation unit 311, 105 Inverse quantization and inverse transformation unit 312, 106 Addition section 320 Prediction Parameter Derivation Unit 10 Video Encoding Device 11 Image encoding device 102 Subtraction section 103 Transformation and Quantization Section 104 Entropy coding unit 110 Encoding parameter determination unit 111 Parameter Encoding Unit 112 Inter-prediction parameter coding unit 113 Intra prediction parameter coding unit 120 Prediction parameter derivation part 71 Reverse conversion information creation device 81 Inverse transformation information coding device 91 Inverse transformation information decoding device

Claims

1. 1. A video decoding device for decoding neural network parameters encoded as additional information, comprising: an inverse transformation information decoding unit that decodes syntax elements indicating information on network parameters of the neural network; A video decoding device comprising: a step of deriving a variable relating to the complexity of said neural network by using a value obtained by shifting a predetermined constant to the left by the value of said syntax element.

2. A video encoding device that encodes neural network parameters as additional information, comprising: an inverse transformation information encoding unit that encodes a syntax element indicating information related to a network parameter of the neural network; A video encoding device comprising: a processor for deriving a variable relating to the complexity of the neural network using a value obtained by shifting a predetermined constant to the left by the value of the syntax element.

Images