JP2021158546A - Image decoding device and image encoding device - Google Patents

Abstract

To provide a video encoding device and a video decoding device that achieve efficient encoding and decoding even in lossless encoding.SOLUTION: The device sets a lossless flag in a sequence parameter set SPS or picture parameter set PPS and sets on/off flags for joint residual encoding, quantization, and loop filter, which are not used in lossless encoding, by referring to the lossless flag.SELECTED DRAWING: Figure 11

Description

Embodiments of the present invention relate to an image decoding device and an image coding device.

In order to efficiently transmit or record an image, an image coding device that generates coded data by encoding the image and an image decoding device that generates a decoded image by decoding the coded data It is used.

Specific image coding methods include, for example, H.264 / AVC and HEVC (High-Efficiency Video).
Coding) method and the like.

In such an image coding method, the image (picture) constituting the moving image is a slice obtained by dividing the image, or a coding tree unit (CTU) obtained by dividing the slice. , A coding unit obtained by dividing a coding tree unit (sometimes called a coding unit (CU)), and
It is managed by a hierarchical structure consisting of a transformation unit (TU: Transform Unit) obtained by dividing the coding unit, and is encoded / decoded for each CU.

Further, in such an image coding method, a predicted image is usually generated based on a locally decoded image obtained by encoding / decoding an input image, and the predicted image is subtracted from the input image (original image). The resulting prediction error (sometimes referred to as a "difference image" or "residual image") is encoded. Examples of the method for generating a prediction image include inter-screen prediction (inter-screen prediction) and in-screen prediction (intra-prediction).

In addition, Non-Patent Document 1 is mentioned as a recent image coding and decoding technique. In Non-Patent Document 1, in order to improve the coding efficiency, the conversion coefficient calculated by dequantizing the quantization conversion coefficient related to the prediction error is estimated without encoding the positive or negative code of some conversion coefficients. "Sign Hiding, SGH", which is a technology to be used, is disclosed. Further, "Dependent Quantization (DQ)" is disclosed in which two quantizers having different levels are switched to perform quantization and dequantization. Further, a technique for dividing the screen into CTU blocks and then recursively dividing the CTU into a plurality of trees such as a quadtree, a binary tree, and a ternary tree called a multi-tree MTT (QTBT, QTBTTT) is disclosed. ing.

On the other hand, in applications where images are used in medical treatments, works of art, etc., there are cases where a decoded image with no or almost no deterioration due to coding is required. In order to realize such lossless or near lossless, a technique that does not use conversion (inverse transformation) or quantization (inverse quantization) in coding (decoding) is disclosed.

"Versatile Video Coding (Draft 8)", JVET-Q2001, Joint Video Exploration Team (JVET) of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29/WG 11, 7-17 January 2020

In Non-Patent Document 1, when lossless coding is used, some tools may not need to be notified of a flag indicating whether the tool is valid or invalid. Since unnecessary flags are notified, there is a problem that the coding efficiency is lowered.

Further, since Non-Patent Document 1 allows various division methods including quadtrees, binary trees, and ternary trees, there is a problem that processing delay occurs due to a large amount of processing during lossless coding.

The present invention has been made in view of the above problems, and an object of the present invention is to realize a moving image coding device and a moving image decoding device that realize efficient coding / decoding even in lossless coding. There is.

Set the lossless flag in the sequence parameter set SPS or the picture parameter set PPS. As a result, the joint residual coding, conversion, quantization, and loop filter on / off flags that are not used during lossless coding are set with reference to the lossless flags.

Further, on the coding side, the maximum block size that can be divided is limited in the quadtree, binary, and ternary division.

According to one aspect of the present invention, even in lossless coding, there is an effect that efficient coding / decoding can be realized.

It is the schematic which shows the structure of the image transmission system which concerns on this embodiment. It is a figure which showed the structure of the transmitting device equipped with the moving image coding device which concerns on this embodiment, and the receiving device equipped with moving image decoding device. PROD_A indicates a transmitting device equipped with a moving image coding device, and PROD_B indicates a receiving device equipped with a moving image decoding device. It is a figure which showed the structure of the recording device which carried out the moving image coding device which concerns on this embodiment, and the reproduction device which carried out the moving image decoding device. PROD_C indicates a recording device equipped with a moving image coding device, and PROD_D indicates a playback device equipped with a moving image decoding device. It is a figure which shows the hierarchical structure of the data of a coded stream. It is a figure which shows the division example of CTU. It is the schematic which shows the structure of the moving image decoding apparatus. It is a flowchart explaining the schematic operation of the moving image decoding apparatus. It is a syntax table of the sequence parameter set which concerns on this embodiment. It is a syntax table of the sequence parameter set which concerns on this embodiment. It is a syntax table of the sequence parameter set which concerns on this embodiment. It is a syntax table of the slice header and TU which concerns on this embodiment. It is a syntax table of the picture parameter set which concerns on this embodiment. It is a syntax table of the picture header which concerns on this embodiment. It is a syntax table of the slice header and TU which concerns on this embodiment. It is a flowchart explaining the operation of the CT information decoding unit which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the moving image coding apparatus.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing a configuration of an image transmission system 1 according to the present embodiment.

The image transmission system 1 is a system that transmits a coded stream in which a coded image is encoded, decodes the transmitted coded stream, and displays an image. The image transmission system 1 includes a moving image coding device (image coding device) 11, a network 21, a moving image decoding device (image decoding device) 31, and an image display device (image display device) 41.

The image T is input to the moving image coding device 11.

The network 21 transmits the coded stream Te generated by the video coding device 11 to the video decoding device 31. The network 21 is an Internet (Internet), a wide area network (WAN: Wide Area Network), a small network (LAN: Local Area Network), or a combination thereof. The network 21 is not necessarily limited to a two-way communication network, but may be a one-way communication network that transmits broadcast waves such as terrestrial digital broadcasting and satellite broadcasting. Further, the network 21 may be replaced with a storage medium on which a coded stream Te such as a DVD (Digital Versatile Disc: registered trademark) or BD (Blue-ray Disc: registered trademark) is recorded.

The moving image decoding device 31 decodes each of the coded streams Te transmitted by the network 21 and generates one or a plurality of decoded images Td.

The image display device 41 displays all or a part of one or a plurality of decoded images Td generated by the moving image decoding device 31. The image display device 41 includes, for example, a display device such as a liquid crystal display or an organic EL (Electro-luminescence) display. Examples of the display form include stationary, mobile, and HMD. Further, when the moving image decoding device 31 has a high processing capacity, an image having a high image quality is displayed, and when the moving image decoding device 31 has a lower processing capacity, an image which does not require a high processing capacity and a display capacity is displayed. ..

<Operator>
The operators used herein are described below.

>> is right bit shift, << is left bit shift, & is bitwise AND, | is bitwise OR
, | = Is the OR assignment operator, and || indicates the OR.

x? y: z is a ternary operator that takes y when x is true (other than 0) and z when x is false (0).

Clip3 (a, b, c) is a function that clips c to a value greater than or equal to a and less than or equal to b. Is a function that returns c (where a <= b).

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

Int (a) is a function that returns an integer value of a.

floor (a) is a function that returns the smallest integer less than or equal to a.

ceil (a) is a function that returns the largest integer greater than or equal to a.

a / d represents the division of a by d (rounded down to the nearest whole number).

<Structure of coded stream Te>
Prior to the detailed description of the moving image coding device 11 and the moving image decoding device 31 according to the present embodiment, the data of the coded stream Te generated by the moving image coding device 11 and decoded by the moving image decoding device 31. The structure will be described.

FIG. 4 is a diagram showing a hierarchical structure of data in the coded stream Te. The coded stream Te typically includes a sequence and a plurality of pictures that make up the sequence. In FIG. 4, the coded video sequence that defines the sequence SEQ, the coded picture that defines the picture PICT, the coded slice that defines the slice S, the coded slice data that defines the slice data, and the coded slice data, respectively. A diagram showing a coded tree unit included and a coded unit included in the coded tree unit is shown.

(Coded video sequence)
The coded video sequence defines a set of data that the moving image decoding device 31 refers to in order to decode the sequence SEQ to be processed. As shown in the encoded video sequence of FIG. 4, the sequence SEQ includes a video parameter set (Video Parameter Set), a sequence parameter set SPS (Sequence Parameter Set), a picture parameter set PPS (Picture Parameter Set), and a picture header (picture header). ), Picture PICT, and Supplemental Enhancement Information (SEI).

The video parameter set VPS defines a set of coding parameters common to a plurality of images and a set of coding parameters related to a plurality of layers included in the image and each layer in an image composed of a plurality of layers. Has been done.

The sequence parameter set SPS defines a set of coding parameters that the moving image decoding device 31 refers to in order to decode the target sequence. For example, the width and height of the picture are specified. There may be a plurality of SPS. In that case, select one of multiple SPSs from PPS.

The picture parameter set PPS defines a set of coding parameters that the moving image decoding device 31 refers to in order to decode each picture in the target sequence. For example, a reference value of the quantization width used for decoding a picture (pic_init_qp_minus26), a flag indicating the application of weighted prediction (weighted_pred_flag), and a scaling list (quantization matrix) are included. There may be a plurality of PPSs. In that case, one of a plurality of PPSs is selected from each picture in the target sequence.

In the picture header PH, coding parameters common to all slices included in one coded picture are defined. For example, it includes coding parameters related to POC (Picture Order Count) and division.

(Coded picture)
The coded picture defines a set of data referred to by the moving image decoding device 31 in order to decode the picture PICT to be processed. The picture PICT includes slices 0 to NS-1 as shown in the coded picture in FIG. 4 (NS is the total number of slices contained in the picture PICT).
..

In the following, when it is not necessary to distinguish between slice 0 and slice NS-1, the subscripts of the symbols may be omitted. The same applies to the data included in the coded stream Te described below and with subscripts.

(Coded slice)
The coded slice defines a set of data referred to by the moving image decoding device 31 in order to decode the slice S to be processed. The slices are as shown in the coded slice of FIG.
Contains slice header and slice data.

The slice header contains a group of coding parameters referred to by the moving image decoding device 31 to determine the decoding method of the target slice. The slice type specification information (slice_type) that specifies the slice type is an example of the coding parameter included in the slice header.

The slice types that can be specified by the slice type specification information include (1) I slices that use only intra-prediction during coding, and (2) P-slices that use unidirectional prediction or intra-prediction during coding. (3) B-slices that use unidirectional prediction, bidirectional prediction, or intra prediction at the time of coding can be mentioned. Note that the inter-prediction is not limited to single prediction and bi-prediction, and a prediction image may be generated using more reference pictures. Hereinafter, when referred to as P and B slices, they refer to slices containing blocks for which inter-prediction can be used.

The slice header may include a reference (pic_parameter_set_id) to the picture parameter set PPS.

(Coded slice data)
The coded slice data defines a set of data referred to by the moving image decoding device 31 in order to decode the slice data to be processed. The slice data contains a CTU, as shown in the coded slice header of FIG. A CTU is a fixed-size (for example, 64x64) block that constitutes a slice, and is sometimes called a maximum coding unit (LCU).

(Coded tree unit)
The coded tree unit of FIG. 4 defines a set of data referred to by the moving image decoding device 31 in order to decode the CTU to be processed. CTU is a recursive quadtree division (QT (Quad Tree))
Division), binary tree division (BT (Binary Tree) division) or ternary tree division (TT (Ternary Tree))
It is divided into the coding unit CU, which is the basic unit of the coding process. The BT division and the TT division are collectively called a multi-tree division (MT (Multi Tree) division). A tree-structured node obtained by recursive quadtree division is called a coding node. The intermediate nodes of quadtrees, binary trees, and ternary trees are coded nodes, and the CTU itself is also defined as the highest level coded node.

The CT includes a division flag indicating whether or not to perform QT division as CT information. Figure 5 shows an example of division.

The CU is the terminal node of the coding node and is not divided any further. The CU is the basic unit of coding processing.

(Code-coding unit)
As shown in the coding unit of FIG. 4, a set of data referred to by the moving image decoding device 31 for decoding the coding unit to be processed is defined. Specifically, the CU is composed of a CU header CUH, a prediction parameter, a conversion parameter, a quantization conversion coefficient, and the like. The CU header defines the prediction mode and so on.

The prediction process may be performed in CU units or in sub-CU units that are further divided CUs. If the size of the CU and the sub CU are equal, there is only one sub CU in the CU. CU is a sub CU
If it is larger than the size of, 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 4 sub CUs consisting of 2 horizontal divisions and 2 vertical divisions.

There are at least two types of prediction (prediction mode CuPredMode): intra prediction (MODE_INTRA) and inter prediction (MODE_INTER). Intrablock copy prediction (MODE_IBC)
May be provided. Intra-prediction and intra-block copy prediction are predictions within the same picture, and inter-prediction refers to prediction processing performed between different pictures (for example, between display times and between layer images).

The conversion / quantization process is performed in CU units, but the quantization conversion coefficient may be entropy-coded in subblock units such as 4x4.

The prediction image is derived by the prediction parameters associated with the block.

(Configuration of moving image decoding device)
The configuration of the moving image decoding device 31 (FIG. 6) according to the present embodiment will be described.

The moving image decoding device 31 includes an entropy decoding unit 301, a parameter decoding unit (predicted image decoding device) 302, a loop filter 305, a reference picture memory 306, a predicted parameter memory 307, a predicted image generator (predicted image generator) 308, and a reverse. It is composed of a quantization / inverse conversion unit 311 and an addition unit 312. In addition, there is also a configuration in which the loop filter 305 is not included in the moving image decoding device 31 in accordance with the moving image coding device 11 described later.

The parameter decoding unit 302 further includes a header decoding unit 3020, a CT information decoding unit 3021, and a CU decoding unit 3022 (prediction mode decoding unit), and the CU decoding unit 3022 includes a TU decoding unit 3024. These may be generically called a decoding module. The header decoding unit 3020 decodes the parameter set information such as VPS, SPS, PPS, and PH, and the slice header (slice information) from the encoded data. The CT information decoding unit 3021 decodes the CT from the coded data. The CU decoding unit 3022 decodes the CU from the coded data. The TU decoding unit 3024 decodes the QP update information (quantization correction value) and the quantization conversion coefficient (residual_coding) from the encoded data.

The TU decoding unit 3024 decodes the QP update information and the quantization conversion coefficient from the coded data when the TU contains a prediction error. Different processes are performed for the derivation of the normal prediction error using transformation (RRC: Regular Residual Coding) and the derivation of the prediction error in the transformation skip mode without transformation (TSRC: Transform Skip Residual Coding). The QP update information is a difference value from the quantization parameter prediction value qPpred, which is the prediction value of the quantization parameter QP.

In the following, an example in which CTU and CU are used as the processing unit will be described, but the processing is not limited to this example, and processing may be performed in sub-CU units. Alternatively, CTU and CU may be read as blocks, sub-CUs may be read as sub-blocks, and processing may be performed in units of blocks or sub-blocks.

The entropy decoding unit 301 performs entropy decoding on the coded stream Te input from the outside, and parses each code (syntax element). For entropy coding, a method of variable-length coding of syntax elements using a context (probability model) adaptively selected according to the type of syntax element and the surrounding situation, a predetermined table, or There is a method of variable-length coding the syntax element using a calculation formula. CABAC (Context Adaptive Binary Arithmetic Coding) is an example of the former. The parsed code includes prediction information for generating a prediction image, prediction error for generating a difference image, and the like.

The entropy decoding unit 301 outputs the parsed code to the parameter decoding unit 302. The parsed code is, for example, the prediction mode CuPredMode. The control of which code is parsed is performed based on the instruction of the parameter decoding unit 302.

(Basic flow)
FIG. 7 is a flowchart illustrating the schematic operation of the moving image decoding device 31.

(S1100: Decoding parameter set information) The header decoding unit 3020 decodes parameter set information such as VPS, SPS, and PPS from the encoded data.

(S1200: Decoding of slice information) The header decoding unit 3020 decodes the slice header (slice information) from the coded data.

Hereinafter, the moving image decoding device 31 sets S1300 to S5000 for each CTU included in the target picture.
The decoded image of each CTU is derived by repeating the process of.

(S1300: CTU information decoding) The CT information decoding unit 3021 decodes the CTU from the encoded data.

(S1400: CT information decoding) The CT information decoding unit 3021 decodes the CT from the encoded data.

(S1500: CU decoding) The CU decoding unit 3022 executes S1510 and S1520 to decode the CU from the coded data.

(S1510: CU information decoding) The CU decoding unit 3022 decodes CU information, prediction information, TU division flag split_transform_flag, CU residual flag cbf_cb, cbf_cr, cbf_luma, etc. from the encoded data.

(S1520: TU information decoding) The TU decoding unit 3024 decodes the QP update information and the quantization conversion coefficient from the coded data when the TU contains a prediction error.

(S2000: Prediction image generation) The prediction image generation unit 308 generates a prediction image based on the prediction information for each block included in the target CU.

(S3000: Inverse quantization / inverse transformation) The inverse quantization / inverse transformation unit 311 executes the inverse quantization / inverse transformation processing for each TU included in the target CU.

(S4000: Decoded image generation) The addition unit 312 decodes the target CU by adding the prediction image supplied by the prediction image generation unit 308 and the prediction error supplied by the inverse quantization / inverse conversion unit 311. Generate an image.

(S5000: Loop filter) The loop filter 305 applies a loop filter such as a deblocking filter, SAO (Sample Adaptive Filter), and ALF (Adaptive Loop Filter) to the decoded image to generate a decoded image.
(SPS lossless control flag)
In the present invention, a lossless flag (first) indicating whether or not the coded data in SPS is in lossless mode.
Flag) is notified. The image decoded from the coded data indicating the lossless mode is lossless, that is, it means that the original image is completely reproduced. The lossless mode is a mode in which the quantization process, the conversion process, and the loop filter process (first process) are not performed. In the lossless mode, a part of the predetermined prediction process (second process) may be further disabled.

When the lossless flag indicates that it is in lossless mode (sps_lossless_mode_enabled_flag == 1), the header decoding unit 3020 of the image decoding device includes a loop filter and a flag indicating the availability of conversion and quantization (included in the first process). The second flag indicating the availability of the tool) is not decoded, but a predetermined value is set. Other than the above (when the lossless flag does not indicate that it is in the lossless mode (sps_lossless_mode_enabled_flag == 0)), the header decoding unit 3020 may decode the second flag.

The header coding unit 1110 of the moving image coding device does not encode the second flag when indicating that the lossless flag is in the lossless mode. Otherwise, the header decoding unit 3020 sets a predetermined value in the second flag indicating that the loop filter, transformation, and quantization are not used.

Further, when the lossless flag indicates that the lossless mode is set, the flag indicating the availability of the predetermined prediction process (the fourth flag indicating the availability of the tool included in the second process) is not notified. The header decoding unit 3020 of the image decoding device sets a predetermined value. Other than the above (when the lossless flag does not indicate that the lossless mode is set), the header decoding unit 3020 may decode the fourth flag.

The header coding unit 1110 of the moving image coding device does not encode the second flag when indicating that the lossless flag is in the lossless mode. Otherwise, the header coding unit 1110 sets the second flag to a value indicating that it does not utilize the loop filter and the availability of transformation and quantization.

An example of SPS is shown in FIGS. 8a to 8c. sps_lossless_mode_enabled_flag is a lossless flag (first flag) indicating whether or not the mode is lossless mode. sps_lossless_mode_enabled_flag = 1 indicates that it is in lossless mode. sps_lossless_mode_enabled_flag = 0 indicates that it may not be in lossless mode. In the figure, when sps_lossless_mode_enabled_flag is 1, the second flags related to quantization and loop filter (first process) (loop_filter_across_subpic_enabled_flag, sps_joint_cbcr_enabled_flag, same_qp_table_for_chroma)
, Sps_sao_enabled_flag, sps_alf_enabled_flag, sps_max_luma_transform_size_64_flag, sps_transform_skip_enabled_flag, log2_transform_skip_max_size_minus2, sps_mts_enabled_flag, sps_sbt_enabled_flag, sps_lmcs_enabled_flag, sps_lfnst_enabled_flag, sps_ladf_enabled_flag, sps_scaling_list_enabled_flag, sps_dep_quant_enabled_flag), and, fourth flag (Sps_sbtmvp_enabled_flag according to predetermined prediction processing (second processing), sps_bdof_enabled_flag, sps_smvd_enabled_flag , Sps_dmvr_enabled_flag, sps_mmvd_enabled_flag, sps_isp_enabled_flag, sps_mrl_enabled_flag, sps_mip_enabled_flag, sps_affine_enabled_flag, sps_affine_prof_enabled_flag, sps_ciip_enabled_flag, sps_gpm_enabled_flag) On the other hand, when sps_lossless_mode_enabled_flag is 0, the second flag and the fourth flag are notified.

More specifically, when sps_lossless_mode_enabled_flag = 1, the following flags indicating the availability of the loop filter may be set to 0 without encoding or decoding.
loop_filter_across_subpic_enabled_flag
sps_sao_enabled_flag
sps_alf_enabled_flag
sps_ladf_enabled_flag
Further, when sps_lossless_mode_enabled_flag = 1, the following flags indicating the availability of joint color difference residual prediction may be set to 0 without encoding or decoding.
sps_joint_cbcr_enabled_flag
Further, when sps_lossless_mode_enabled_flag = 1, the following flags indicating the availability of conversion may be set to 0 without encoding or decoding.
sps_mts_enabled_flag
sps_sbt_enabled_flag
sps_lfnst_enabled_flag
Further, when sps_lossless_mode_enabled_flag = 1, the following flags indicating the availability of the quantization matrix and LMCS may be set to 0 without encoding or decoding.
sps_scaling_list_enabled_flag
sps_lmcs_enabled_flag
Further, when sps_lossless_mode_enabled_flag = 1, the following flags indicating the availability of quantization may be set to 0 without encoding or decoding.
sps_dep_quant_enabled_flag
From the above, there is an effect that all the processes that hinder the realization of losslessness can be turned off.

Further, when sps_lossless_mode_enabled_flag = 1, the following flag indicating the availability of conversion skip may be set to the value (1) indicating that it can be used without encoding or decoding.
sps_transform_skip_enabled_flag
Furthermore, when sps_lossless_mode_enabled_flag = 1, the following flags (syntax elements) indicating the maximum TU size may be set to 0 so that the conversion skip becomes the maximum available TU size without encoding or decoding. ..
sps_max_luma_transform_size_64_flag
Further, when sps_lossless_mode_enabled_flag = 1, the following flag (syntax element) indicating the size of conversion skip may be set to 3 indicating the maximum size without encoding or decoding.
log2_transform_skip_max_size_minus2
From the above, there is an effect that the conversion skip required for the realization of losslessness is enabled, and the TU size and the conversion skip size can be set so that the conversion skip can be used in all conversion units (TUs).

Further, when sps_lossless_mode_enabled_flag = 1, the following flags indicating the availability of joint color difference residual prediction may be set to 1 without encoding or decoding.
same_qp_table_for_chroma
(Explanation of the first process and the second flag)
The first process is a loop filter, quantization, and transformation process, and the second flag relates to the availability of the first process. The loop filtering may be deblocking filtering (DBF, DF), sample adaptive offset processing (SAO), adaptive loop filtering (ALF), bilateral filter, or the like. The quantization process may be a process (conversion skip) in which the conversion coefficient is not quantized and the conversion is not performed and only the residual coefficient is scaled. It may be a predictive decoding process (joint coding) of the quantization conversion coefficient. It may be a process of changing the quantization parameter (process of the color difference quantization mapping table).

Alternatively, it may be a flag related to the availability of conversion processing. For example, it may be a secondary conversion LFNST that additionally performs conversion. It may be a process (MTS) of switching and converting a plurality of conversion bases. In the inter-prediction, the TU may be divided into two sub-blocks and only one sub-block may be converted (SBT).

The second flag may be the following loop filter, quantization, conversion, conversion skip flag, or conversion size syntax element. If sps_lossless_mode_enabled_flag = 1,
The second flag does not have to be present in the coded data. If each flag (syntax element) does not exist, a predetermined value is set. The meaning of each of the second flags and the predetermined values set when they are not notified are described below.

(Loop filter flag)
loop_filter_across_subpic_enabled_flag [i] = 1 indicates that each picture in this CLVS (coded layer video sequence) is subjected to loop filtering across the boundary of the i-th sub-picture. loop_filter_across_subpic_enabled_flag [i] = 0 indicates that each picture in this CLVS is not loop filtered across the boundary of the i-th sub-picture. If the above flag does not exist, such as when sps_lossless_mode_enabled_flag = 1, the value of loop_filter_across_subpic_enabled_pic_flag [i] is set to 1-sps_independent_subpics_flag. If the above flag does not exist, loop_filter_across_subpic_enabled_pic_flag [i] may be set to 0 if sps_lossless_mode_enabled_flag = 1, otherwise (sps_lossless_mode_enabled_flag = 0), 1-sps_independent_subpics_flag may be set.

CLVS is a sequence of prediction blocks having the same value of nuh_layer_id. This sequence begins with the PU of the IRAP picture and is followed by the PU of the IRAP or non-IRAP in the decoding order.

sps_sao_enabled_flag = 1 indicates that SAO processing is applied to the reproduced picture after deblocking filtering. sps_sao_enabled_flag = 0 indicates that SAO processing is not applied to the replayed picture after deblocking filtering. If it does not exist, sps_sao_enabled_flag is set to 0.

sps_alf_enabled_flag = 0 indicates that ALF is not available. sps_alf_enabled_flag = 1 indicates that ALF is available. If sps_lossless_mode_enabled_flag = 1, this flag does not have to be present in the coded data and is set to 0.

(Quantization flag)
sps_joint_cbcr_enabled_flag = 0 indicates that the joint coding of the color difference prediction error is not available. sps_joint_cbcr_enabled_flag = 1 indicates that joint coding of color difference prediction errors is available. If it does not exist, the value of sps_joint_cbcr_enabled_flag is set to 0.

The joint coding of the color difference prediction error is a process of coding or decoding the prediction errors of the two color difference components as one absolute value and a code. One encoded absolute value and sign (
From ±), calculate the prediction errors for Cb and Cr, respectively.

The same_qp_table_for_chroma = 1 indicates that one color difference quantization mapping table is notified and is applied to the prediction error of Cb and Cr, and further, if sps_joint_cbcr_enabled_flag = 1, it is applied to the prediction error of the joint coding of Cb and Cr.

same_qp_table_for_chroma = 0 indicates that two quantization mapping tables are notified for Cb and Cr, and if sps_joint_cbcr_enabled_flag = 1, one more quantization mapping table is notified for joint coding of Cb and Cr. If it does not exist, the value of same_qp_table_for_chroma is set to 1.

sps_lmcs_enabled_flag = 1 is LMCS (luma mapping with chroma scaling) in this CLVS
Indicates that is used. sps_lmcs_enabled_flag = 0 indicates that LMCS is not used in this CLVS. If it does not exist, sps_lmcs_enabled_flag is set to 0.

LMCS is a loop filter process that derives a linear model based on the luminance component and changes the histogram of the pixel values of the reference image, and is also a quantization process that scales the prediction error of the color difference based on the luminance value.

sps_ladf_enabled_flag = 1 indicates that the LADF syntax element is present in this SPS. sps_ladf_enabled_flag = 0 indicates that the LADF syntax element does not exist in this SPS. If it does not exist, sps_ladf_enabled_flag is set to 0.

LADF is a process for correcting the quantization value of the luminance used in the deblocking filter.

sps_scaling_list_enabled_flag = 1 indicates that the scaling list is used for the (inverse) quantization process of the conversion factors. sps_scaling_list_enabled_flag = 0 indicates that the scaling list is not used for the conversion coefficient quantization process. If it does not exist, sps_scaling_list_enabled_flag is set to 0.

sps_dep_quant_enabled_fla = 0 indicates that dependent quantization is not available in the pictures that reference this SPS. sps_dep_quant_enabled_fla = 1 indicates that dependent quantization may be available in pictures that reference this SPS. If it does not exist, sps_dep_quant_enabled_flag is set to 0.

The dependent quantization is a process of switching between two quantizers having different levels to quantize and dequantize.

(Conversion flag)
sps_mts_enabled_flag = 1 indicates that sps_explicit_mts_intra_enabled_flag and sps_explicit_mts_inter_enabled_flag are present in the SPS. sps_mts_enabled_flag = 0 indicates that sps_explicit_mts_intra_enabled_flag and sps_explicit_mts_inter_enabled_flag do not exist in SPS. If it does not exist, sps_mts_enabled_flag is set to 0.

Note that MTS (Multiple transform selection) is a process of switching and transforming a plurality of transformation bases.

sps_lfnst_enabled_flag = 1 indicates that lfnst_idx may be present in the intra-prediction CU. sps_lfnst_enabled_flag = 0 indicates that lfnst_idx does not exist in the intra-prediction CU. If it does not exist, sps_lfnst_enabled_flag is set to 0.

LFNST is a process that applies a non-separable orthogonal transformation.

sps_sbt_enabled_flag = 0 indicates that SBT (subblock transform for inter-predicted CUs) is not available. sps_sbt_enabled_flag = 1 indicates that SBT is available. If it does not exist, sps_sbt_enabled_flag is set to 0.

Note that SBT is a process of dividing the TU into two sub-blocks and converting only one of the sub-blocks in the inter-prediction.

(Conversion skip flag)
sps_transform_skip_enabled_flag = 1 indicates that transform_skip_flag may be included in the TU syntax. sps_transform_skip_enabled_flag = 0 means transform
Indicates that _skip_flag is not included in the TU syntax. If it does not exist, sps_transform_skip_enabled_flag is set to 1.

(Conversion size flag)
sps_max_luma_transform_size_64_flag = 1 indicates that the maximum TU size of the luminance pixel is 64 in the conversion process. sps_max_luma_transform_size_64_flag = 0 indicates that the maximum TU size of the luminance sample is 32 in the transformation process. Specifically, the logarithmic value of the maximum conversion block size of the luminance pixel is derived by the following equation.
MaxTbLog2SizeY = sps_max_luma_transform_size_64_flag? 6: 5
log2_transform_skip_max_size_minus2 indicates the logarithmic minus 2 of the maximum block size of Transform Skip (TS) processing when sps_transform_skip_enabled_flag = 1. Specifically, the maximum block size of TS processing is derived by the following formula.
MaxTsSize = 1 << (log2_transform_skip_max_size_minus2 + 2)
When the value of the maximum size of the conversion block is larger than the value of the maximum size of the TS block, a conversion block to which TS processing cannot be applied occurs. Therefore, when the lossless flag sps_lossless_mode_enabled_flag of SPS is 1, sps_max_luma_transform_size_64_flag = 0 and log2_transform_skip_max_size_minus2 = 3 are set. From the above, in the case of lossless coding, the maximum size of both the conversion block and the TS block is 32, and the TS processing can be applied to the conversion block.

(Explanation of the fourth flag and the second process)
The fourth flag relates to the availability of a second process relating to the predetermined prediction process. The second process may be, for example, as follows. It may be a subblock-based motion vector prediction (SBTMVP) in the time direction. In the bi-prediction, it may be a process (SMVD) of deriving the reference picture indexes of L0 and L1 and the differential motion vector of L1 without notifying them. In the merge mode, it may be a process (MMVD) in which the motion vector is refined. When deriving the predicted image from the two motion compensation images, it may be a process (BDOF) of correcting by using the gradient image. In bi-prediction, it may be a process of refining a motion vector (DMVR). Intra-prediction processing (ISP) may be performed in which the prediction block is divided into two or four in either the vertical or horizontal direction. It may be a process (MRL) of intra-predicting by referring to a plurality of lines from adjacent blocks. In the inter-prediction, the TU may be divided into two sub-blocks and only one sub-block may be converted (SBT). It may be a matrix-based intra-prediction (MIP). It may be an affine model-based motion compensation. It may be a refinement of the prediction by optical flow in the affine model-based motion compensation. It may be a process (CIIP) of generating a predicted image by weighting an intra-predicted image and an inter-predicted image. It may be a motion compensation image (GPM) having a non-rectangular shape.

When sps_lossless_mode_enabled_flag = 1, the fourth flag (syntax element) does not have to exist in the coded data. If each flag does not exist, a predetermined value is set. The meaning of each of the fourth flags and the predetermined values set when they are not notified are described below.

sps_sbtmvp_enabled_flag = 1 indicates that in this CLVS, subblock-based temporal motion vector prediction may be used to decode pictures containing at least one non-intraslice. sps_sbtmvp_enabled_flag = 0 indicates that subblock-based temporal motion vector prediction is not used in this CLVS. If it does not exist, sps_stmvp_enabled_flag is set to 0. If it does not exist, sps_sbtmvp_enabled_flag is set to 0.

sps_bdof_enabled_flag = 0 means BDOF (bi-directional optical flow inter prediction)
) Indicates that it is not available. sps_bdof_enabled_flag = 1 indicates that BDOF is available. If it does not exist, sps_bdof_enabled_flag is set to 0.

sps_smvd_enabled_flag = 1 indicates that SMVD (symmetric motion vector difference) is used to decode the motion vector. sps_smvd_enabled_flag = 0 indicates that SMVD is not used to decode motion vectors. If it does not exist, sps_smvd_enabled_flag is set to 0.

sps_dmvr_enabled_flag = 1 indicates that DMVR (decoder motion vector refinement based inter bi-prediction) is available. sps_dmvr_enabled_flag = 0 indicates that DMVR is not available. If it does not exist, sps_dmvr_enabled_flag is set to 0.

sps_mmvd_enabled_flag = 1 indicates that MMVD (merge mode with motion vector difference) is available. sps_mmvd_enabled_flag = 0 indicates that MMVD is not available. If it does not exist, sps_mmvd_enabled_flag is set to 0.

sps_isp_enabled_flag = 1 indicates that ISP (specifies that intraprediction with subpartitions) is available. sps_isp_enabled_flag = 0 indicates that the ISP is unavailable. If it does not exist, sps_isp_enabled_flag is set to 0.

sps_mrl_enabled_flag = 1 is MRL (intra prediction with multiple reference lines)
) Is available. sps_mrl_enabled_flag = 0 indicates that MRL is not available. If it does not exist, sps_mrl_enabled_flag is set to 0.

sps_mip_enabled_flag = 1 indicates that matrix-based intra-prediction (MIP) is available. sps_mip_enabled_flag = 0 indicates that matrix-based intra-prediction is not available. If it does not exist, sps_mip_enabled_flag is set to 0.

sps_affine_enabled_flag is a flag indicating whether or not affine model-based motion compensation is used. sps_affine_enabled_flag = 0 indicates that affine model-based motion compensation is not used in this CLVS. sps_affine_enabled_flag = 1 indicates that affine model-based motion compensation is used in this CLVS. If it does not exist, sps_afine_enabled_flag is set to 0.

sps_affine_prof_enabled_flag, a flag that indicates whether or not optical flow prediction refinement is used in affine model-based motion compensation. sps_affine_prof_enabled_flag = 0 indicates that affine model-based motion compensation is not refined by optical flow. sps_affine_prof_enabled_flag = 1 indicates that affine model-based motion compensation is refined by optical flow. If it does not exist, sps_afine_prof_enabled_flag is set to 0.

sps_ciip_enabled_flag is a flag that indicates that ciip_flag may be present in the inter-prediction CU. sps_ciip_enabled_flag = 0 indicates that ciip_flag does not exist in the inter-predicted CU. If it does not exist, sps_ciip_enabled_flag is set to 0.

CIIP is a process of generating a prediction image by weighting an intra prediction image and an inter prediction image.

sps_gpm_enabled_flag is a flag indicating whether or not a motion compensation image having a non-rectangular shape can be used. sps_gpm_enabled_flag = 0 indicates that non-rectangular motion compensation images cannot be used with this CLVS. sps_gpm_enabled_flag = 1 indicates that this CLVS can use non-rectangular motion compensation images. If it does not exist, sps_gpm_enabled_flag is set to 0.

An example of the slice header is shown in Fig. 9 (a). When sps_lossless_mode_enabled_flag is 0 and sps_transform_skip_enabled_flag is set to 1 When sps_transform_skip_enabled_flag is 1, slice_ts_residual_coding_disabled_flag is decrypted in the slice header.

slice_ts_residual_coding_disabled_flag = 1 indicates that in this slice, the normal prediction error syntax (residual_coding) that uses transformation is used to parse the prediction residuals of the transformation skip block. slice_ts_residual_coding_disabled_flag = 0 indicates that in this slice, the syntax of prediction error without conversion (residual_ts_coding) is used to parse the prediction residuals of the conversion skip block. If it does not exist, if sps_lossless_mode_enabled_flag is 1, slice_ts_residual_coding_disabled_flag
Is set to 1, and if sps_lossless_mode_enabled_flag is 0, slice_ts_residual_coding_disabled_flag is set to 0.

According to the above, when the lossless flag is 1, there is an effect that the slice_ts_residual_coding_disabled_flag can be efficiently decoded without being encoded.

(Third flag)
Flags (sao_info_in_ph_flag, alf_info_in_ph_flag, qp_delta_info_in_ph_flag) that specify the loop filter and the position to notify information about quantization will be described. Hereinafter, these flags will be referred to as a third flag. If sps_lossless_mode_enabled_flag is 1, the third flag is not notified and set to the specified value. The meaning of each of the third flags and the predetermined values set when not notified are described below.

sao_info_in_ph_flag = 1 indicates that SAO information is present in the picture header and not in the slice header. sao_info_in_ph_flag = 0 indicates that SAO information does not exist in the picture header and may exist in the slice header that references this PPS. If it does not exist, sao_info_in_ph_flag is set to 0.

alf_info_in_ph_flag = 1 indicates that the ALF information is present in the picture header and not in the slice header. alf_info_in_ph_flag = 0 indicates that the ALF information does not exist in the picture header and may exist in the slice header that references this PPS. If it does not exist, alf_info_in_ph_flag is set to 0.

qp_delta_info_in_ph_flag = 1 indicates that the difference information of the quantization parameter exists in the picture header and not in the slice header. qp_delta_info_in_ph_flag = 0 indicates that the difference information of the quantization parameter does not exist in the picture header and may exist in the slice header that references this PPS. If it does not exist, qp_delta_info_in_ph_flag is set to 0.

In FIGS. 8a to 8c, the notification and non-notification of the second flag and the third flag are switched with reference to sps_lossless_mode_enabled_flag, but only the notification and non-notification of the second flag may be switched.

The header decoding unit 3020 decodes sps_lossless_mode_enabled_flag in SPS. When sps_lossless_mode_enabled_flag is 1, the header decoding unit 3020 does not decode the above flag in the slice header and sets a predetermined value. When sps_lossless_mode_enabled_flag is 0, the header decoding unit 3020 decodes the above flag in the SPS and the slice header.

As described above, in the case of lossless coding, in a tool that does not require notification of a flag indicating whether it is valid or invalid, the image decoding device sets a predetermined value without notifying the flag. Therefore, since unnecessary flags are not notified, there is an effect that the coding efficiency is improved.

(Another configuration of SPS lossless flag)
Lossless flag of SPS When sps_lossless_mode_enabled_flag is 1, the loop filter notified by PPS and the sixth flag related to the availability of quantization (loop_filter_across_tiles_enabled_flag, loop_filter_across_slices_enabled_flag, cu_qp_delta_enabled_flag, cu_qp_delta_enabled_flag, cu_qp_delta_enabled_flag, cu_qp_delta_enabled_flag, cu_qp_delta_enabled_flag, cu_qp_delta_enabled_flag There may be. When the sps_lossless_mode_enabled_flag is 1, the coded data decoded by the header decoding unit 3020 of the moving image decoding device 31 having this configuration must have the following values.

loop_filter_across_tiles_enabled_flag = 0
loop_filter_across_slices_enabled_flag = 0
cu_qp_delta_enabled_flag = 0
pps_chroma_tool_offsets_present_flag = 0
deblocking_filter_control_present_flag = 1
sps_max_luma_transform_size_64_flag = 0
log2_transform_skip_max_size_minus2 = 3
Note that the deblocking_filter_control_present_flag may be the flag deblocking_filter_enabled_flag that enables the deblocking filter or the flag deblocking_filter_disabled_flag that disables the deblocking filter.

deblocking_filter_enabled_flag = 0
deblocking_filter_disabled_flag = 1
In this configuration, the header decoding unit 3020 notifies the sixth flag regardless of the value of sps_lossless_mode_enabled_flag. However, the sixth flag must have the above-mentioned predetermined value when sps_lossless_mode_enabled_flag = 1.

In the above configuration, the availability of related tools is limited depending on the sps_lossless_mode_enabled_flag. At the same time, the PPS decoding does not depend on the value of the SPS flag, that is, the PPS can be decoded independently of the SPS decoding.

(PPS lossless control flag)
In the following configuration, a configuration for notifying the lossless flag by PPS will be described.

An example of PPS is shown in FIG. pps_lossless_mode_enabled_flag is a flag (fifth flag) indicating whether or not the mode is lossless mode notified by PPS. pps_lossless_mode_enabled_flag = 1 indicates that it is in lossless mode. pps_lossless_mode_enabled_flag = 0 indicates that it is not in lossless mode.

An example of PPS is shown in FIG. When pps_lossless_mode_enabled_flag is 1, the sixth flags related to the availability of loop filters and quantizations transmitted by PPS (loop_filter_across_tiles_enabled_flag, loop_filter_across_slices_enabled_flag, cu_qp_delta_enabled_flag, pps_chroma_tool_offsets_present_flag, deblocking
, Qp_delta_info_in_ph_flag) is not notified. On the other hand, pps_lossless_mode_enabled_flag
If is 0, the sixth flag is notified. That is, the header coding unit 1110 of the moving image encoding device does not encode the sixth flag when pps_lossless_mode_enabled_flag is 1, and the header decoding unit 3020 of the moving image decoding device does not encode the sixth flag. Do not decode.

The header decoding unit 3020 decodes pps_lossless_mode_enabled_flag in PPS. When the pps_lossless_mode_enabled_flag is 1, the header decoding unit 3020 may set a predetermined value without decoding the flags (sixth to tenth flags) described later in the PPS and the slice header. When pps_lossless_mode_enabled_flag is 0, the header decoding unit 3020 decodes the above flag in the PPS and the slice header.

The sixth flag may be the following loop filter, quantization, conversion, conversion skip flag, or conversion size syntax element. If sps_lossless_mode_enabled_flag = 1, the second flag does not have to be present in the coded data. If each flag (syntax element) does not exist, a predetermined value is set. The meaning of each of the sixth flags and the predetermined values set when they are not notified are described below.

loop_filter_across_tiles_enabled_flag = 1 indicates that loop filtering is performed across tile boundaries in pictures that reference this PPS. loop_filter_across_tiles_enabled_flag = 0 indicates that no loop filtering is performed across tile boundaries in pictures that reference this PPS. Loop filters include deblocking filters, pixel adaptive offsets (SAOs), and adaptive loop filters (ALFs). If it does not exist, the value of loop_filter_across_tiles_enabled_pic_flag is set to 1.

loop_filter_across_slices_enabled_flag = 1 indicates that loop filtering is performed across tile boundaries in pictures that reference this PPS. loop_filter_across_slices_enabled_flag = 0 indicates that no loop filtering is performed across tile boundaries in pictures that reference this PPS. Loop filters include deblocking filters, pixel adaptive offsets (SAOs), and adaptive loop filters (ALFs). If it does not exist, the value of loop_filter_across_slices_enabled_pic_flag is set to 0.

cu_qp_delta_enabled_flag = 1 is a picture header that refers to this PPS and is a flag that indicates that the prediction of the quantization parameter is available. cu_qp_delta_enabled_flag = 0 is a picture header that refers to this PPS and is a flag indicating that the prediction of the quantization parameter is not available. If it does not exist, pps_qp_delta_enabled_flag is set to 0.

pps_chroma_tool_offsets_present_flag = 1 is a flag indicating that the parameter related to the quantization value of the color difference exists in this PPS. pps_chroma_tool_offsets_present_flag = 0 is a flag indicating that the parameter related to the quantization value of the color difference does not exist in this PPS.
If it does not exist, pps_qp_delta_enabled_flag is set to 0.

deblocking_filter_control_present_flag = 1 indicates that the deblocking filter parameters are present in this PPS. deblocking_filter_control_present_flag = 0 indicates that the deblocking filter parameter does not exist in this PPS. If it does not exist, deblocking_filter_control_present_flag is set to 0.

If it can be determined from the PPS flag that it is in lossless mode, the above information related to the loop filter encoded by PPS and quantization is not used, so no notification is given.

Also, since it is not quantized by the conversion skip used in lossless, information related to the quantization parameter (cu_qp_delta_enabled_flag, pps_chroma_tool_offsets_present_flag,
qp_delta_info_in_ph_flag) is not notified.

When pps_lossless_mode_enabled_flag is 1, the third flags (sao_info_in_ph_flag, alf_info_in_ph_flag) that specify the position to encode the loop filter information notified by PPS are not notified. On the other hand, if pps_lossless_mode_enabled_flag is 0, the third flag of PPS is notified.

The loop filter notified by PH and the flags related to the availability of quantization and conversion will be described below. Hereinafter, these flags will be referred to as the ninth flag.

When the lossless flag is 1 (pps_lossless_mode_enabled_flag is 1), the ninth shown in FIG.
Flags (ph_lmcs_enabled_flag, ph_dep_quant_enabled_flag) are not notified. On the other hand, if pps_lossless_mode_enabled_flag is 0, the ninth flag is notified. That is, when the header coding unit 1110 of the moving image coding device has pps_lossless_mode_enabled_flag of 1,
The ninth flag is not encoded, and the header decoding unit 3020 of the moving image decoding device does not decode the ninth flag. The above processing may be performed as sps_lossless_mode_enabled_flag instead of pps_lossless_mode_enabled_flag.

If pps_lossless_mode_enabled_flag is 1, the ninth flag does not have to be present in the coded data. Hereinafter, the ninth flag and a predetermined value set when the flag does not exist will be described.

ph_lmcs_enabled_flag = 1 indicates that LMCS (luma mapping with chroma scaling) is used in the current picture. ph_lmcs_enabled_flag = 0 indicates that LMCS is not used in the current picture. If it does not exist, ph_lmcs_enabled_flag is set to 0.

ph_dep_quant_enabled_flag = 0 indicates that dependent quantization is not available in the current picture. ph_dep_quant_enabled_flag = 1 indicates that dependent quantization may be available in the current picture. If it does not exist, ph_dep_quant_enabled_flag is set to 0.

Further, the logarithmic value of the maximum conversion block size of the luminance pixel is derived by the following equation. MaxTbLog2SizeY = pps_lossless_mode_enabled_flag? 5: (sps_max_luma_transform_size_64_flag? 6: 5)
Then, the logarithmic value of the maximum block size of TS processing is derived by the following equation.
log2_transform_skip_max_size_minus2 = pps_lossless_mode_enabled_flag? 3: log2_transform_skip_max_size_minus2
MaxTsSize = 1 << (log2_transform_skip_max_size_minus2 + 2)
When the value of the maximum size of the conversion block is larger than the value of the maximum size of the TS block, a conversion block to which TS processing cannot be applied occurs. Therefore, when the lossless flag pps_lossless_mode_enabled_flag of PPS is 1, MaxTbLog2SizeY = 5 and log2_transform_skip_max_size_minus2 = 3 are set regardless of the value of the SPS flag. From the above, in the case of lossless coding, TS processing can be applied to the conversion block.

In addition, in lossless mode, some prediction tools may be turned off as they increase the amount of processing, even though they have little effect. Specifically, when pps_lossless_mode_enabled_flag is 1, the eighth flag (ph_disable_dmvr_flag, ph_disable_bdof_flag, ph_disable_prof_flag) related to the availability of the predetermined prediction process notified by PH is not notified. On the other hand, if pps_lossless_mode_enabled_flag is 0, the eighth flag is notified. That is, when the pps_lossless_mode_enabled_flag is 1, the header coding unit 1110 of the moving image encoding device does not notify the eighth flag, and the header decoding unit 3020 of the moving image decoding device does not decode the eighth flag. ..
The eighth flag may include:

DMVR on / off flag ph_disable_dmvr_flag
BDOF on / off flag ph_disable_bdof_flag
PROF on / off flag ph_disable_prof_flag
Hereinafter, the eighth flag related to the prediction will be described.

ph_disable_dmvr_flag = 1 indicates that DMVR (decoder motion vector refinement based inter bi-prediction) is not available in the current picture. ph_disable_dmvr_flag = 0 indicates that DMVR is available. If it does not exist, ph_disable_dmvr_flag is set to 0.

ph_disable_bdof_flag = 1 indicates that BDOF (bi-directional optical flow interprediction) is not available in the current picture. ph_disable_bdof_flag = 0 indicates that DMVR is available. If it does not exist, ph_disable_bdof_flag is set to 0.

ph_disable_prof_flag = 1 indicates that PROF (Prediction Refinement with Optical Flow) is not available in the current picture. ph_disable_prof_flag = 0 indicates that DMVR is available. If it does not exist, ph_disable_prof_flag is set to 0.

Further, when pps_lossless_mode_enabled_flag is 1, the third flag that refers to the second flag whose value is set to 0 in PPS is not notified and is set to a predetermined value. The third flag is, for example, sao_info_in_ph_flag or alf_info_in_ph_flag.

An example of the slice header is shown in FIG. 12 (a). If pps_lossless_mode_enabled_flag is 0 and sps_transform_skip_enabled_flag is 1, slice_ts_residual_coding_disabled_flag is decrypted. If it does not exist and pps_lossless_mode_enabled_flag is 1, set slice_ts_residual_coding_disabled_flag to 1. If sps_lossless_mode_enabled_flag is 0, set slice_ts_residual_coding_disabled_flag to 0.

According to the above, when the lossless flag is 1, there is an effect that efficient decoding processing can be performed without encoding slice_ts_residual_coding_disabled_flag.

When the lossless flag is 1 (pps_lossless_mode_enabled_flag = 1), the slice header flags (slice_sao_luma_flag and slice_alf_enabled_flag) regarding the availability of the first process are not notified and are set to 0. The lossless flag may be sps_lossless_mode_enabled_flag.

slice_sao_luma_flag = 1 indicates that SAO information exists in the slice header. slice_sao_luma_flag = 0 indicates that SAO information does not exist in the slice header.

slice_alf_enabled_flag = 1 indicates that ALF information exists in the slice header. slice_alf_enabled_flag = 0 indicates that it does not exist in the slice header.

(SPS lossless flag and PPS lossless flag)
A configuration with an SPS-level lossless flag sps_lossless_mode_enabled_flag and a configuration with a PPS-level lossless flag pps_lossless_mode_enabled_flag are not exclusive.

That is, the configuration may be such that SPS notifies sps_lossless_mode_enabled_flag and PPS notifies pps_lossless_mode_enabled_flag. In this case, if sps_lossless_mode_enabled_flag is 1, then pps_lossless_mode_enabled_flag must always be 1. If sps_lossless_mode_enabled_flag is 0, the value of pps_lossless_mode_enabled_flag is unrestricted.

With the above configuration, it is possible to realize coded data that is lossless within an appropriate range. In other words, lossless can be realized at the entire sequence level that refers to SPS, or lossless can be realized at the picture level that refers to PPS.
(BT, TT division size limit of coded tree unit)
(Processing of CT information decoding)
Hereinafter, the CT information decoding process will be described with reference to FIG. FIG. 13 is a flowchart illustrating the operation of the CT information decoding unit according to the embodiment of the present invention.

FIG. 13 is a flowchart illustrating the operation of the CT information decoding unit 3021 according to the embodiment of the present invention.

The CT information decoding unit 3021 decodes the CT information from the coded data and recursively decodes the coding tree CT (coding_tree). Specifically, the CT information decoding unit 3021 decodes the QT information and decodes the target CT coding_tree (x0, y0, cbWidth, cbHeight, cqtDepth, mttDepth). Note that (x0, y0) is the upper left coordinate of the target CT, cbWidth and cbHeight are the width and height of the CT, and cqtDepth and mttDepth are the layers of QT and BT / TT.

(S1411) The CT information decoding unit 3021 determines whether or not the decoded CT information has a QT split flag (split_cu_flag). The QT division flag is a flag indicating whether or not to perform QT division. If there is a QT split flag, it transitions to S1421, otherwise it transitions to S1422.

(S1421) The CT information decoding unit 3021 decodes the QT division flag.

(S1422) In other cases, the CT information decoding unit 3021 omits decoding of split_cu_flag and sets a predetermined value in split_cu_flag.

(S1450) If split_cu_flag is other than 0, it transitions to S1451, otherwise it transitions to S1471.

(S1451) The CT information decoding unit 3021 performs QT division. Specifically, the CT information decoding unit 3021 divides into four CT decodings shown by QT in FIG.

Then, the CT information decoding unit 3021 updates cqtDepth, cbWidth, and cbHeight, and continues the QT information decoding started from S1411 even in the lower CT.
After the QT division is completed, the CT information decoding unit 3021 decodes the CT information from the coded data and recursively performs the BT or TT division.

(S1471) The CT information decoding unit 3021 adds the MT split flag (mtt_split_cu_vertical_flag) to the CT information.
, Mtt_split_cu_binary_flag). If there is an MT division flag, it transitions to S1481. In other cases, it transitions to S1482. mtt_split_cu_vertical_flag is a flag indicating the direction of MT division. mtt_split_cu_binary_flag is a flag indicating whether the MT division is a binary tree or a ternary tree.

(S1481) The CT information decoding unit 3021 decodes the MT division flag.

(S1482) The CT information decoding unit 3021 does not decode the MT division flag split_mt_flag from the coded data and sets it to a predetermined value.

(S1490) The CT information decoding unit 3021 transitions to S1491 when the MT split flag split_mt_flag is other than 0. In other cases, the CT information decoding unit 3021 does not divide the target CT and ends the process (shifts to decoding the CU).

(S1491) CT information decoding unit 3021 performs MT division. With reference to mtt_split_cu_vertical_flag and mtt_split_cu_binary_flag, one of BT (vertical division), BT (horizontal division), TT (vertical division), and TT (horizontal division) in Fig. 5 is performed.

Then, the CT information decoding unit 3021 updates mttDepth, cbWidth, and cbHeight, and continues BT / TT information decoding starting from S1471 even in the lower CT.

In addition, the CT information decoding unit 3021 uses the CU decoding unit 3022 when neither QT division nor BT / TT division is performed.
Decrypt the CU with.

When the first flag (sps_lossless_mode_enabled_flag) or the fifth flag (pps_lossless_mode_enabled_flag) is 1, the maximum division size MaxBtSizeY of BT and the maximum division size MaxTtSizeY of TT are set to a predetermined fixed value TS_TH0 (for example, 8) or less.

Specifically, the CT information decoding unit 3021 (and the CU information encoding unit) derives MaxBtSizeY and MaxTtSizeY from the following equations.

Intra slice and when the first flag is 1:
MaxBtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_intra_slice_luma)
MaxTtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_tt_min_qt_intra_slice_luma)
Or, if it is an intra slice and the fifth flag is 1.
MaxBtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_intra_slice_luma)
MaxTtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_tt_min_qt_intra_slice_luma)
When interslicing and the first flag is 1:
MaxBtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_inter_slice)
MaxTtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_tt_min_qt_inter_slice)
Or, if it is intersliced and the fifth flag is 1.
MaxBtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_inter_slice)
MaxTtSizeY = Min (TS_TH0, 1 << (MinQtLog2SizeY + ph_log2_diff_max_tt_min_qt_inter_slice)
Here, MinQtLog2SizeY is the logarithmic value of the minimum block size of the QT division. ph_log2_diff_max_bt_min_qt_inter_slice is the difference between the logarithm of the minimum block size of the QT division and the logarithm of the minimum block size in the intraslice. ph_log2_diff_max_tt_min_qt_inter_slice is the difference between the logarithm of the minimum block size of the QT division and the logarithm of the minimum block size in the interslice.

Further, MaxBtSizeY and MaxTtSizeY may be derived as follows.

For intra slices:
MaxBtSizeY = (sps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_bt_min_qt_intra_slice_luma)
MaxTtSizeY = (sps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_tt_min_qt_intra_slice_luma)
or,
MaxBtSizeY = (pps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_bt_min_qt_intra_slice_luma)
MaxTtSizeY = (pps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_tt_min_qt_intra_slice_luma)
For interslicing:
MaxBtSizeY = (sps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_bt_min_qt_inter_slice)
MaxTtSizeY = (sps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_tt_min_qt_inter_slice)
or,
MaxBtSizeY = (pps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_bt_min_qt_inter_slice)
MaxTtSizeY = (pps_lossless_mode_enabled_flag)? TS_TH0: 1 << (MinQtLog2SizeY +
ph_log2_diff_max_tt_min_qt_inter_slice)
According to the moving image decoding apparatus having the above configuration, since the BT division and the TT division occur only in the block size of a predetermined fixed value or less, the division hierarchy and the number of combinations of the BT division and the TT division are limited. By limiting the number of divisions, the processing complexity and processing delay of the moving image decoding device can be reduced.

(Configuration of moving image coding device)
Next, the configuration of the moving image coding device 11 according to the present embodiment will be described. FIG. 14 is a block diagram showing the configuration of the moving image coding device 11 according to the present embodiment. The moving image coding device 11 includes a prediction image generation unit 101, a subtraction unit 102, a conversion / quantization unit 103, an inverse quantization / inverse conversion unit 105, an addition unit 106, a loop filter 107, and a prediction parameter memory (prediction parameter storage unit). , Frame memory) 108, reference picture memory (reference image storage unit, frame memory) 109, coding parameter determination unit 110, parameter coding unit 111, and entropy coding unit 104.

The prediction image generation unit 101 generates a prediction image for each CU, which is a region in which each picture of the image T is divided.

The subtraction unit 102 subtracts the pixel value of the predicted image of the block input from the prediction image generation unit 101 from the pixel value of the image T to generate a prediction error. The subtraction unit 102 converts the prediction error and the quantization unit 103.
Output to.

The conversion / quantization unit 103 calculates the conversion coefficient by frequency conversion with respect to the prediction error input from the subtraction unit 102, and derives the quantization conversion coefficient by quantization. The conversion / quantization unit 103
The quantization conversion coefficient is output to the entropy coding unit 104 and the inverse quantization / inverse conversion unit 105.

The inverse quantization / inverse transformation unit 105 is the inverse quantization / inverse transformation unit 311 (FIG. 6) in the moving image decoding device 31.
Is the same as. The calculated prediction error is output to the addition unit 106.

A quantization conversion coefficient is input to the entropy coding unit 104 from the conversion / quantization unit 103, and a coding parameter is input from the parameter coding unit 111. The coding parameter is, for example, predMode indicating the prediction mode. The predMode may be either MODE_INTRA indicating an intra-prediction or MODE_INTER indicating an inter-prediction, or may be MODE_INTRA, MODE_INTER, or MODE_IBC.

The entropy coding unit 104 entropy-codes the division information, the prediction parameters, the quantization conversion coefficient, and the like to generate a coded stream Te, and outputs the coded stream Te.

The parameter coding unit 111 includes a header coding unit 1110 (not shown), a CT information coding unit 1111 and a CU.
It includes a coding unit 1112 (prediction mode coding unit), an inter prediction parameter coding unit 112, and an intra prediction parameter coding unit 113. The CU coding unit 1112 further includes the TU coding unit 1114.
It has.

The outline operation of each module will be described below. The parameter coding unit 111 performs parameter coding processing such as header information, division information, prediction information, and quantization conversion coefficient.

The CT information coding unit 1111 uses sps_lossless_mode_enabled_flag in SPS for lossless coding.
Is encoded. In addition, QT, MT (BT, TT) division information, etc. are encoded in the hierarchy below the CTU.
(Limited division size of coded tree unit)
In lossless coding, the CT information coding unit 1111 sets MaxBtSizeY and MaxTtSizeY, which indicate the maximum tree size of BT and TT division, to 8. That is, in lossless coding, the maximum block size that can be divided as BT and TT is set to 8x8 or less. This reduces the number of combinations of search division depths and types required to determine the division information, and has the effect of reducing complexity and processing delay in the coding process.

For the above processing, the CT information coding unit 1111 may encode the maximum tree size. For example, in lossless coding, ph_log2_diff_max_bt_min_qt_intra_slice_luma = 0 and ph_log2_diff_max_bt_min_qt_inter_slice = 0 may be set. Here, ph_log2_diff_max_bt_min_qt_intra_slice_luma defines a binary representation of the difference between the maximum size (width or height) of the BT-dividable block and the minimum size of the CU in the luminance component of the intra slice. ph_log2_diff_max_bt_min_qt_inter_slice defines a binary representation of the difference between the maximum size (width or height) of a BT-dividable block and the minimum size of a CU in an interslice.

MaxBtSizeY = 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_intra_slice_luma)
MaxBtSizeY = 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_inter_slice)
Alternatively, it may be set in the same manner as on the decoding side.

MaxBtSizeY = sps_lossless_mode_enabled_flag? 8: 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_intra_slice_luma)
MaxBtSizeY = sps_lossless_mode_enabled_flag? 8: 1 << (MinQtLog2SizeY + ph_log2_diff_max_bt_min_qt_inter_slice)
The CU coding unit 1112 encodes CU information, prediction information, a TU division flag, a CU residual flag, and the like.

The TU coding unit 1114 encodes the QP update information and the quantization conversion coefficient when the TU contains a prediction error.

The CT information coding unit 1111 and the CU coding unit 1112 supply the entropy coding unit 104 with syntax elements such as inter-prediction parameters, intra-prediction parameters, and quantization conversion coefficients.

The addition unit 106 adds the pixel value of the prediction image of the block input from the prediction image generation unit 101 and the prediction error input from the inverse quantization / inverse conversion unit 105 for each pixel to generate a decoded image. The addition unit 106 stores the generated decoded image in the reference picture memory 109.

The loop filter 107 applies a deblocking filter, SAO, and ALF to the decoded image generated by the addition unit 106. The loop filter 107 does not necessarily have to include the above three types of filters, and may have, for example, a configuration of only a deblocking filter.

SAO is a filter that adds an offset according to the classification result for each sample, and ALF is a filter that uses the sum of products of the notified filter coefficient and the reference image (or the difference between the reference image and the target pixel).

The prediction parameter memory 108 stores the prediction parameters generated by the coding parameter determination unit 110 at predetermined positions for each target picture and CU.

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

The coding parameter determination unit 110 selects one set from the plurality of sets of coding parameters. The coding parameter is the above-mentioned QT, BT or TT division information, prediction parameter, or a parameter to be coded generated in connection with these. The prediction image generation unit 101 generates a prediction image using these coding parameters.

The coding parameter determination unit 110 calculates an RD cost value indicating the magnitude of the amount of information and the coding error for each of the plurality of sets. The coding parameter determination unit 110 selects the set of coding parameters that minimizes the calculated cost value. As a result, the entropy coding unit 104 outputs the selected set of coding parameters as the coding stream Te. The coding parameter determination unit 110 stores the determined coding parameter in the prediction parameter memory 108.

A part of the moving image coding device 11 and the moving image decoding device 31 in the above-described embodiment, for example, the entropy decoding unit 301, the parameter decoding unit 302, the loop filter 305, the prediction image generation unit 308, and the inverse quantization / reverse. Conversion unit 311, Addition unit 312, Prediction image generation unit 101, Subtraction unit 102, Conversion / quantization unit 103, Entropy coding unit 104, Inverse quantization / inverse conversion unit 105, Loop filter 107, Coding parameter determination unit 110 , The parameter coding unit 111 may be realized by a computer. In that case, the program for realizing this control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed. The "computer system" referred to here is a computer system built in any of the moving image coding device 11 and the moving image decoding device 31, and includes hardware such as an OS and peripheral devices. Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system. Furthermore, a "computer-readable recording medium" is a medium that dynamically holds a program for a short period of time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In that case, a program may be held for a certain period of time, such as a volatile memory inside a computer system serving as a server or a client. Further, the above-mentioned program may be a program for realizing a part of the above-mentioned functions, and may be a program for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Further, a part or all of the moving image coding device 11 and the moving image decoding device 31 in the above-described embodiment may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each functional block of the moving image coding device 11 and the moving image decoding device 31 may be individually converted into a processor, or a part or all of them may be integrated into a processor. Further, the method of making an integrated circuit is not limited to the LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, when an integrated circuit technology that replaces an LSI appears due to advances in semiconductor technology, an integrated circuit based on this technology may be used.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to the above, and various design changes and the like are made without departing from the gist of the present invention. It is possible to do.

[Application example]
The moving image coding device 11 and the moving image decoding device 31 described above can be mounted on and used in various devices that transmit, receive, record, and reproduce moving images. The moving image may be a natural moving image captured by a camera or the like, or an artificial moving image (including CG and GUI) generated by a computer or the like.

First, it will be described with reference to FIG. 2 that the moving image coding device 11 and the moving image decoding device 31 described above can be used for transmitting and receiving moving images.

FIG. 2 shows a block diagram showing the configuration of the transmission device PROD_A equipped with the moving image coding device 11. As shown in the figure, the transmitter PROD_A has a coding unit PROD_A1 that obtains coded data by encoding a moving image, and a modulation signal by modulating a carrier with the coded data obtained by the coding unit PROD_A1. It includes a modulation unit PROD_A2 to obtain and a transmission unit PROD_A3 to transmit the modulation signal obtained by the modulation unit PROD_A2. The moving image coding device 11 described above is used as the coding unit PROD_A1.

The transmitter PROD_A has a camera PROD_A4 for capturing a moving image, a recording medium PROD_A5 for recording a moving image, an input terminal PROD_A6 for inputting a moving image from the outside, and a moving image as a source of the moving image to be input to the coding unit PROD_A1. , An image processing unit A7 for generating or processing an image may be further provided. In the figure, the configuration in which the transmitter PROD_A is provided with all of these is illustrated, but some of them may be omitted.

The recording medium PROD_A5 may be a recording of an unencoded moving image, or a moving image encoded by a recording coding method different from the transmission coding method. It may be a thing. In the latter case, a decoding unit (decoding unit) that decodes the coded data read from the recording medium PROD_A5 between the recording medium PROD_A5 and the coding unit PROD_A1 according to the coding method for recording.
It is advisable to intervene (not shown).

Further, FIG. 2 shows a block diagram showing the configuration of the receiving device PROD_B equipped with the moving image decoding device 31. As shown in the figure, the receiving device PROD_B is obtained by a receiving unit PROD_B1 that receives a modulated signal, a demodulating unit PROD_B2 that obtains coded data by demodulating the modulated signal received by the receiving unit PROD_B1, and a demodulating unit PROD_B2. It includes a decoding unit PROD_B3 that obtains a moving image by decoding the encoded data. The moving image decoding device 31 described above is used as the decoding unit PROD_B3.

The receiving device PROD_B is a display PROD_B4 for displaying the moving image, a recording medium PROD_B5 for recording the moving image, and an output terminal for outputting the moving image to the outside as a supply destination of the moving image output by the decoding unit PROD_B3. It may also have PROD_B6. In the figure, the configuration in which the receiving device PROD_B is provided with all of these is illustrated, but some of them may be omitted.

The recording medium PROD_B5 may be used for recording an unencoded moving image, or may be encoded by a recording coding method different from the transmission coding method. You may. In the latter case, a coding unit (not shown) that encodes the moving image acquired from the decoding unit PROD_B3 according to the recording coding method may be interposed between the decoding unit PROD_B3 and the recording medium PROD_B5.

The transmission medium for transmitting the modulated signal may be wireless or wired. Further, the transmission mode for transmitting the modulated signal may be broadcasting (here, a transmission mode in which the destination is not specified in advance) or communication (here, transmission in which the destination is specified in advance). Refers to an aspect). That is, the transmission of the modulated signal may be realized by any of wireless broadcasting, wired broadcasting, wireless communication, and wired communication.

For example, a broadcasting station (broadcasting equipment, etc.) / receiving station (television receiver, etc.) of 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. Further, a broadcasting station (broadcasting equipment, etc.) / receiving station (television receiver, etc.) of cable television broadcasting is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives modulated signals by wired broadcasting.

In addition, servers (workstations, etc.) / clients (television receivers, personal computers, smartphones, etc.) for VOD (Video On Demand) services and video sharing services using the Internet are transmitters that send and receive modulated signals via communication. This is an example of PROD_A / receiver PROD_B (usually, in LAN, either wireless or wired is used as a transmission medium, and in WAN, wired is used as a transmission medium). Here, personal computers include desktop PCs, laptop PCs, and tablet PCs. Smartphones also include multifunctional mobile phone terminals.

The client of the video sharing service has a function of decoding the encoded data downloaded from the server and displaying it on the display, as well as a function of encoding the moving image captured by the camera and uploading it to the server. That is, the client of the video sharing service functions as both the transmitting device PROD_A and the receiving device PROD_B.

Next, it will be described with reference to FIG. 3 that the moving image coding device 11 and the moving image decoding device 31 described above can be used for recording and reproducing a moving image.

FIG. 3 shows a block diagram showing the configuration of the recording device PROD_C equipped with the moving image coding device 11 described above. As shown in the figure, the recording device PROD_C has a coding unit PROD_C1 that obtains coded data by encoding a moving image and a writing unit PROD_C2 that writes the coded data obtained by the coding unit PROD_C1 to the recording medium PROD_M. And have. The above-mentioned moving image coding device 11
Is used as this coding unit PROD_C1.

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

Further, the recording device PROD_C has a camera PROD_C3 that captures a moving image, an input terminal PROD_C4 for inputting a moving image from the outside, and a reception for receiving the moving image as a source of the moving image to be input to the coding unit PROD_C1. The unit PROD_C5 and the image processing unit PROD_C6 for generating or processing an image may be further provided. In the figure, the configuration in which the recording device PROD_C is provided with all of these is illustrated, but some of them may be omitted.

The receiving unit PROD_C5 may receive an unencoded moving image, or receives coded data encoded by a transmission coding method different from the recording coding method. It may be something to do. In the latter case, it is preferable to interpose a transmission decoding unit (not shown) for decoding the coded data encoded by the transmission coding method between the receiving unit PROD_C5 and the coding unit PROD_C1.

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

Further, FIG. 3 shows a block diagram showing the configuration of the reproduction device PROD_D equipped with the above-mentioned moving image decoding device 31. As shown in the figure, the playback device PROD_D includes a reading unit PROD_D1 that reads the coded data written in the recording medium PROD_M, and a decoding unit PROD_D2 that obtains a moving image by decoding the coded data read by the reading unit PROD_D1. , Is equipped. The moving image decoding device 31 described above is used as the decoding unit PROD_D2.

The recording medium PROD_M may be of a type built in the playback device PROD_D, such as (1) HDD or SSD, or (2) such as an SD memory card or USB flash memory. It may be of a type connected to the playback device PROD_D, or may be loaded into a drive device (not shown) built in the playback device PROD_D, such as (3) DVD or BD. good.

Further, the playback device PROD_D has a display PROD_D3 for displaying the moving image, an output terminal PROD_D4 for outputting the moving image to the outside, and a transmitting unit for transmitting the moving image as a supply destination of the moving image output by the decoding unit PROD_D2. It may also have PROD_D5. In the figure, the configuration in which the playback device PROD_D is provided with all of these is illustrated, but some of them may be omitted.

The transmission unit PROD_D5 may transmit an unencoded moving image, or transmits coded data encoded by a transmission coding method different from the recording coding method. It may be something to do. In the latter case, it is preferable to interpose a coding unit (not shown) that encodes the moving image by a coding method for transmission between the decoding unit PROD_D2 and the transmitting unit PROD_D5.

Examples of such a playback device PROD_D include a DVD player, a BD player, an HDD player, and the like (in this case, the output terminal PROD_D4 to which a television receiver or the like is connected is the main supply destination of moving images). .. Also, the television receiver (in this case, display PROD_D3)
Is the main supply destination for moving images), digital signage (also called electronic signage or electronic bulletin board, and the display PROD_D3 or transmitter PROD_D5 is the main supply destination for moving images), desktop PC (in this case, Output terminal PROD_D4 or transmitter PROD_D5 is the main source of moving images), laptop or tablet PC (in this case, display PROD_D3 or transmitter PROD_D5)
Is the main supply destination for moving images), smartphones (in this case, the display PROD_D3 or the transmitter PROD_D5 is the main supply destination for moving images), and the like are also examples of such a playback device PROD_D.

(Hardware realization and software realization)
Further, each block of the moving image decoding device 31 and the moving image coding device 11 described above may be realized in hardware by a logic circuit formed on an integrated circuit (IC chip), or may be realized by hardware, or a CPU (Central Processing). It may be realized by software using Unit).

In the latter case, each of the above devices is a CPU that executes instructions of a program that realizes each function, a ROM (Read Only Memory) that stores the above program, and a RAM (Random) that expands the above program.
Access Memory), a storage device (recording medium) such as a memory for storing the above program and various data. Then, an object of the embodiment of the present invention is a record in which the program code (execution format program, intermediate code program, source program) of the control program of each of the above devices, which is software for realizing the above-mentioned functions, is recorded so as to be readable by a computer. It can also be achieved by supplying the medium to each of the above devices and having the computer (or CPU or MPU) read and execute the program code recorded on the recording medium.

Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic discs such as floppy (registered trademark) discs / hard disks, and CD-ROMs (Compact Disc Read-Only Memory) / MO discs (Magneto-Optical discs). ) / MD (Mini Disc) / DVD (Digital Versatile Disc: registered trademark) / CD-R (CD Recordable) / Blu-ray disc (Blu-ray)
Discs including optical discs such as Disc: registered trademark), IC cards (including memory cards)
/ Cards such as optical cards, mask ROM / EPROM (Erasable Programmable Read-Only Memory) / EEPROM (Electrically Erasable and Programmable Read-Only Memory: registered trademark)
/ Semiconductor memories such as flash ROM, or logic circuits such as PLD (Programmable logic device) and FPGA (Field Programmable Gate Array) can be used.

Further, 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 can transmit the program code. For example, Internet, Intranet, Extranet, LAN (Local Area Network), ISDN (Integrated Services Digital Network), VAN (Value-Added Network), CATV (Community Antenna television / Cable Television) communication network, Virtual Private network (Virtual Private) Network), telephone line network, mobile communication network, satellite communication network, etc. can be used. Further, the transmission medium constituting this communication network may be any medium as long as it can transmit the program code, and is not limited to a specific configuration or type. For example, even wired 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, infrared data such as IrDA (Infrared Data Association) and 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. It is also available wirelessly. 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.

The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. That is, an embodiment obtained by combining technical means appropriately modified within the scope of the claims is also included in the technical scope of the present invention.

The embodiment of the present invention is suitably applied to a moving image decoding device that decodes encoded data in which image data is encoded, and a moving image coding device that generates encoded data in which image data is encoded. be able to. Further, it can be suitably applied to the data structure of the coded data generated by the moving image coding device and referenced by the moving image decoding device.

31 Video decoding device
301 Entropy Decryptor
302 Parameter decoder
3020 Header decoder
308 Prediction image generator
311 Inverse quantization / inverse transformation
312 Addition part
11 Video coding device
101 Predictive image generator
102 Subtraction section
103 Transformation / Quantization Department
104 Entropy coding unit
105 Inverse quantization / inverse transformation
107 Loop filter
110 Coding parameter determination unit
111 Parameter coding section
1110 Header coding section
1111 CT information coding unit
1112 CU coding unit (prediction mode coding unit)
1114 TU coding section

Claims (11)

The sequence parameter set SPS is provided with a header decoding unit that decodes the first flag indicating lossless coding.
When the header decoding unit indicates that the first flag is encoded in the lossless coding mode, the header decoding unit does not decode the loop filter and the second flag related to the availability of conversion and quantization, and is predetermined. A moving image decoding apparatus, characterized in that the second flag is decoded when the first flag is not encoded in the lossless coding mode. When the header decoding unit indicates that the first flag is encoded in the lossless coding mode, the header decoding unit indicates that the tool included in the predetermined prediction process (second process) is available. 1 is characterized in that the fourth flag is decoded when a predetermined value is set without decoding and the first flag indicates that the first flag is not encoded in the lossless coding mode. The moving image decoding device according to. When the header decoding unit indicates that the first flag is encoded in the lossless coding mode, the header decoding unit indicates that the tool included in the predetermined prediction process (second process) is available. 1 is characterized in that the third flag is decoded when a predetermined value is set without decoding and the first flag indicates that the first flag is not encoded in the lossless coding mode. The moving image decoding device according to. The sequence parameter set SPS includes a header coding unit that encodes the first flag indicating lossless coding.
When the first flag indicates that the coded data is encoded in the lossless coding mode, the header coding unit does not encode the second flag and sets a predetermined value. , A moving image coding apparatus, characterized in that the second flag is encoded when the first flag indicates that the encoded data is not encoded in the lossless coding mode. When the first flag indicates that the coded data is encoded in the lossless coding mode, the header coding unit does not encode the third and fourth flags and is predetermined. The fourth aspect of claim 4, characterized in that a fourth flag is encoded when a value is set and the first flag indicates that the encoded data is not encoded in lossless encoding mode. Video encoding device. When the first flag indicates that the coded data is encoded in the lossless coding mode, the header coding unit does not encode the third flag and sets a predetermined value. The moving image code according to claim 4, wherein the first flag encodes the third flag when the first flag indicates that the coded data is not encoded in the lossless coding mode. Chemical equipment. The picture parameter set PPS is provided with a header decoding unit that decodes the fifth flag indicating lossless coding.
When the header decoding unit indicates that the fifth flag is encoded in the lossless coding mode, the sixth flag of PPS, which indicates the availability of the loop filter and the quantization, and the loop filter and the quantization, indicate that the fifth flag is encoded. When the ninth flag of PH indicating availability is not decoded and a predetermined value is set to indicate that the fifth flag is not encoded in the lossless coding mode, the sixth flag is set. A moving image decoding device characterized by decoding a flag. When the fifth flag indicates that the coded data is encoded in the lossless coding mode, the header decoding unit does not decode the seventh, eighth, and tenth flags, and determines in advance. When the set value is set and the fifth flag indicates that the coded data is not encoded in the lossless coding mode, the seventh, eighth, and tenth flags are decoded. The moving image decoding device according to claim 7. The picture parameter set PPS includes a header coding unit that encodes a fifth flag indicating lossless coding.
When the header coding unit indicates that the fifth flag is encoded in the lossless coding mode, the loop filter, the PPS flag (sixth flag) indicating the availability of quantization, and the loop filter are used. The PH flag (9th flag) indicating the availability of quantization is not encoded, a predetermined value is set, and the 5th flag is not encoded in the lossless coding mode. In the case of a moving image coding device, the sixth flag and the ninth flag are encoded. When indicating that the fifth flag is encoded in the lossless coding mode, the header coding unit does not encode the seventh, eighth, and tenth flags, but sets a predetermined value. 9; The moving image encoding device according to. In an image decoding device that divides an image into rectangular coded tree units (CTUs) and processes them.
When indicating that the information is encoded in the lossless coding mode, the information decoding unit is a moving image decoding device characterized by deriving a maximum BT and TT division size of 8 or less.

Images