/* SPDX-License-Identifier: LGPL-2.1-or-later */ /* * Copyright (C) 2021, Ideas On Board * * awb.cpp - AWB control algorithm */ #include "awb.h" #include #include #include /** * \file awb.h */ namespace libcamera { namespace ipa::ipu3::algorithms { LOG_DEFINE_CATEGORY(IPU3Awb) /* * When zones are used for the grey world algorithm, they are only considered if * their average green value is at least 16/255 (after black level subtraction) * to exclude zones that are too dark and don't provide relevant colour * information (on the opposite side of the spectrum, saturated regions are * excluded by the ImgU statistics engine). */ static constexpr uint32_t kMinGreenLevelInZone = 16; /* * Minimum proportion of non-saturated cells in a zone for the zone to be used * by the AWB algorithm. */ static constexpr double kMaxCellSaturationRatio = 0.8; /* * Maximum ratio of saturated pixels in a cell for the cell to be considered * non-saturated and counted by the AWB algorithm. */ static constexpr uint32_t kMinCellsPerZoneRatio = 255 * 90 / 100; /** * \struct Accumulator * \brief RGB statistics for a given zone * * Accumulate red, green and blue values for each non-saturated item over a * zone. Items can for instance be pixels, but also the average of groups of * pixels, depending on who uses the accumulator. * \todo move this description and structure into a common header * * Zones which are saturated beyond the threshold defined in * ipu3_uapi_awb_config_s are not included in the average. * * \var Accumulator::counted * \brief Number of unsaturated cells used to calculate the sums * * \var Accumulator::sum * \brief A structure containing the average red, green and blue sums * * \var Accumulator::sum.red * \brief Sum of the average red values of each unsaturated cell in the zone * * \var Accumulator::sum.green * \brief Sum of the average green values of each unsaturated cell in the zone * * \var Accumulator::sum.blue * \brief Sum of the average blue values of each unsaturated cell in the zone */ /** * \struct Awb::AwbStatus * \brief AWB parameters calculated * * The AwbStatus structure is intended to store the AWB * parameters calculated by the algorithm * * \var AwbStatus::temperatureK * \brief Color temperature calculated * * \var AwbStatus::redGain * \brief Gain calculated for the red channel * * \var AwbStatus::greenGain * \brief Gain calculated for the green channel * * \var AwbStatus::blueGain * \brief Gain calculated for the blue channel */ /* Default settings for Bayer noise reduction replicated from the Kernel */ static const struct ipu3_uapi_bnr_static_config imguCssBnrDefaults = { .wb_gains = { 16, 16, 16, 16 }, .wb_gains_thr = { 255, 255, 255, 255 }, .thr_coeffs = { 1700, 0, 31, 31, 0, 16 }, .thr_ctrl_shd = { 26, 26, 26, 26 }, .opt_center = { -648, 0, -366, 0 }, .lut = { { 17, 23, 28, 32, 36, 39, 42, 45, 48, 51, 53, 55, 58, 60, 62, 64, 66, 68, 70, 72, 73, 75, 77, 78, 80, 82, 83, 85, 86, 88, 89, 90 } }, .bp_ctrl = { 20, 0, 1, 40, 0, 6, 0, 6, 0 }, .dn_detect_ctrl = { 9, 3, 4, 0, 8, 0, 1, 1, 1, 1, 0 }, .column_size = 1296, .opt_center_sqr = { 419904, 133956 }, }; /* Default color correction matrix defined as an identity matrix */ static const struct ipu3_uapi_ccm_mat_config imguCssCcmDefault = { 8191, 0, 0, 0, 0, 8191, 0, 0, 0, 0, 8191, 0 }; /** * \class Awb * \brief A Grey world white balance correction algorithm * * The Grey World algorithm assumes that the scene, in average, is neutral grey. * Reference: Lam, Edmund & Fung, George. (2008). Automatic White Balancing in * Digital Photography. 10.1201/9781420054538.ch10. * * The IPU3 generates statistics from the Bayer Down Scaler output into a grid * defined in the ipu3_uapi_awb_config_s structure. * * - Cells are defined in Pixels * - Zones are defined in Cells * * 80 cells * /───────────── 1280 pixels ───────────\ * 16 zones * 16 * ┌────┬────┬────┬────┬────┬─ ──────┬────┐ \ * │Cell│ │ │ │ │ | │ │ │ * 16 │ px │ │ │ │ │ | │ │ │ * ├────┼────┼────┼────┼────┼─ ──────┼────┤ │ * │ │ │ │ │ │ | │ │ * │ │ │ │ │ │ | │ │ 7 * │ ── │ ── │ ── │ ── │ ── │ ── ── ─┤ ── │ 1 2 4 * │ │ │ │ │ │ | │ │ 2 0 5 * * │ │ │ │ │ │ | │ │ z p c * ├────┼────┼────┼────┼────┼─ ──────┼────┤ o i e * │ │ │ │ │ │ | │ │ n x l * │ │ | │ │ e e l * ├─── ───┼─ ──────┼────┤ s l s * │ │ | │ │ s * │ │ | │ │ * ├─── Zone of Cells ───┼─ ──────┼────┤ │ * │ (5 x 4) │ | │ │ │ * │ │ | │ │ │ * ├── ───┼─ ──────┼────┤ │ * │ │ │ | │ │ │ * │ │ │ │ │ │ | │ │ │ * └────┴────┴────┴────┴────┴─ ──────┴────┘ / * * * In each cell, the ImgU computes for each colour component the average of all * unsaturated pixels (below a programmable threshold). It also provides the * ratio of saturated pixels in the cell. * * The AWB algorithm operates on a coarser grid, made by grouping cells from the * hardware grid into zones. The number of zones is fixed to \a kAwbStatsSizeX x * \a kAwbStatsSizeY. For example, a frame of 1280x720 is divided into 80x45 * cells of [16x16] pixels and 16x12 zones of [5x4] cells each * (\a kAwbStatsSizeX=16 and \a kAwbStatsSizeY=12). If the number of cells isn't * an exact multiple of the number of zones, the right-most and bottom-most * cells are ignored. The grid configuration is computed by * IPAIPU3::calculateBdsGrid(). * * Before calculating the gains, the algorithm aggregates the cell averages for * each zone in generateAwbStats(). Cells that have a too high ratio of * saturated pixels are ignored, and only zones that contain enough * non-saturated cells are then used by the algorithm. * * The Grey World algorithm will then estimate the red and blue gains to apply, and * store the results in the metadata. The green gain is always set to 1. */ Awb::Awb() : Algorithm() { asyncResults_.blueGain = 1.0; asyncResults_.greenGain = 1.0; asyncResults_.redGain = 1.0; asyncResults_.temperatureK = 4500; zones_.reserve(kAwbStatsSizeX * kAwbStatsSizeY); } Awb::~Awb() = default; int Awb::configure(IPAContext &context, [[maybe_unused]] const IPAConfigInfo &configInfo) { const ipu3_uapi_grid_config &grid = context.configuration.grid.bdsGrid; stride_ = context.configuration.grid.stride; cellsPerZoneX_ = std::round(grid.width / static_cast(kAwbStatsSizeX)); cellsPerZoneY_ = std::round(grid.height / static_cast(kAwbStatsSizeY)); /* * Configure the minimum proportion of cells counted within a zone * for it to be relevant for the grey world algorithm. * \todo This proportion could be configured. */ cellsPerZoneThreshold_ = cellsPerZoneX_ * cellsPerZoneY_ * kMaxCellSaturationRatio; LOG(IPU3Awb, Debug) << "Threshold for AWB is set to " << cellsPerZoneThreshold_; return 0; } /** * The function estimates the correlated color temperature using * from RGB color space input. * In physics and color science, the Planckian locus or black body locus is * the path or locus that the color of an incandescent black body would take * in a particular chromaticity space as the blackbody temperature changes. * * If a narrow range of color temperatures is considered (those encapsulating * daylight being the most practical case) one can approximate the Planckian * locus in order to calculate the CCT in terms of chromaticity coordinates. * * More detailed information can be found in: * https://en.wikipedia.org/wiki/Color_temperature#Approximation */ uint32_t Awb::estimateCCT(double red, double green, double blue) { /* Convert the RGB values to CIE tristimulus values (XYZ) */ double X = (-0.14282) * (red) + (1.54924) * (green) + (-0.95641) * (blue); double Y = (-0.32466) * (red) + (1.57837) * (green) + (-0.73191) * (blue); double Z = (-0.68202) * (red) + (0.77073) * (green) + (0.56332) * (blue); /* Calculate the normalized chromaticity values */ double x = X / (X + Y + Z); double y = Y / (X + Y + Z); /* Calculate CCT */ double n = (x - 0.3320) / (0.1858 - y); return 449 * n * n * n + 3525 * n * n + 6823.3 * n + 5520.33; } /* Generate an RGB vector with the average values for each zone */ void Awb::generateZones() { zones_.clear(); for (unsigned int i = 0; i < kAwbStatsSizeX * kAwbStatsSizeY; i++) { RGB zone; double counted = awbStats_[i].counted; if (counted >= cellsPerZoneThreshold_) { zone.G = awbStats_[i].sum.green / counted; if (zone.G >= kMinGreenLevelInZone) { zone.R = awbStats_[i].sum.red / counted; zone.B = awbStats_[i].sum.blue / counted; zones_.push_back(zone); } } } } /* Translate the IPU3 statistics into the default statistics zone array */ void Awb::generateAwbStats(const ipu3_uapi_stats_3a *stats) { /* * Generate a (kAwbStatsSizeX x kAwbStatsSizeY) array from the IPU3 grid which is * (grid.width x grid.height). */ for (unsigned int cellY = 0; cellY < kAwbStatsSizeY * cellsPerZoneY_; cellY++) { for (unsigned int cellX = 0; cellX < kAwbStatsSizeX * cellsPerZoneX_; cellX++) { uint32_t cellPosition = cellY * stride_ + cellX; uint32_t zoneX = cellX / cellsPerZoneX_; uint32_t zoneY = cellY / cellsPerZoneY_; uint32_t awbZonePosition = zoneY * kAwbStatsSizeX + zoneX; /* Cast the initial IPU3 structure to simplify the reading */ const ipu3_uapi_awb_set_item *currentCell = reinterpret_cast( &stats->awb_raw_buffer.meta_data[cellPosition] ); /* * Use cells which have less than 90% * saturation as an initial means to include * otherwise bright cells which are not fully * saturated. * * \todo The 90% saturation rate may require * further empirical measurements and * optimisation during camera tuning phases. */ if (currentCell->sat_ratio <= kMinCellsPerZoneRatio) { /* The cell is not saturated, use the current cell */ awbStats_[awbZonePosition].counted++; uint32_t greenValue = currentCell->Gr_avg + currentCell->Gb_avg; awbStats_[awbZonePosition].sum.green += greenValue / 2; awbStats_[awbZonePosition].sum.red += currentCell->R_avg; awbStats_[awbZonePosition].sum.blue += currentCell->B_avg; } } } } void Awb::clearAwbStats() { for (unsigned int i = 0; i < kAwbStatsSizeX * kAwbStatsSizeY; i++) { awbStats_[i].sum.blue = 0; awbStats_[i].sum.red = 0; awbStats_[i].sum.green = 0; awbStats_[i].counted = 0; } } void Awb::awbGreyWorld() { LOG(IPU3Awb, Debug) << "Grey world AWB"; /* * Make a separate list of the derivatives for each of red and blue, so * that we can sort them to exclude the extreme gains. We could * consider some variations, such as normalising all the zones first, or * doing an L2 average etc. */ std::vector &redDerivative(zones_); std::vector blueDerivative(redDerivative); std::sort(redDerivative.begin(), redDerivative.end(), [](RGB const &a, RGB const &b) { return a.G * b.R < b.G * a.R; }); std::sort(blueDerivative.begin(), blueDerivative.end(), [](RGB const &a, RGB const &b) { return a.G * b.B < b.G * a.B; }); /* Average the middle half of the values. */ int discard = redDerivative.size() / 4; RGB sumRed(0, 0, 0); RGB sumBlue(0, 0, 0); for (auto ri = redDerivative.begin() + discard, bi = blueDerivative.begin() + discard; ri != redDerivative.end() - discard; ri++, bi++) sumRed += *ri, sumBlue += *bi; double redGain = sumRed.G / (sumRed.R + 1), blueGain = sumBlue.G / (sumBlue.B + 1); /* Color temperature is not relevant in Grey world but still useful to estimate it :-) */ asyncResults_.temperatureK = estimateCCT(sumRed.R, sumRed.G, sumBlue.B); asyncResults_.redGain = redGain; /* Hardcode the green gain to 1.0. */ asyncResults_.greenGain = 1.0; asyncResults_.blueGain = blueGain; } void Awb::calculateWBGains(const ipu3_uapi_stats_3a *stats) { ASSERT(stats->stats_3a_status.awb_en); clearAwbStats(); generateAwbStats(stats); generateZones(); LOG(IPU3Awb, Debug) << "Valid zones: " << zones_.size(); if (zones_.size() > 10) { awbGreyWorld(); LOG(IPU3Awb, Debug) << "Gain found for red: " << asyncResults_.redGain << " and for blue: " << asyncResults_.blueGain; } } void Awb::process(IPAContext &context, const ipu3_uapi_stats_3a *stats) { calculateWBGains(stats); /* * Gains are only recalculated if enough zones were detected. * The results are cached, so if no results were calculated, we set the * cached values from asyncResults_ here. */ context.frameContext.awb.gains.blue = asyncResults_.blueGain; context.frameContext.awb.gains.green = asyncResults_.greenGain; context.frameContext.awb.gains.red = asyncResults_.redGain; context.frameContext.awb.temperatureK = asyncResults_.temperatureK; } constexpr uint16_t Awb::threshold(float value) { /* AWB thresholds are in the range [0, 8191] */ return value * 8191; } void Awb::prepare(IPAContext &context, ipu3_uapi_params *params) { /* * Green saturation thresholds are reduced because we are using the * green channel only in the exposure computation. */ params->acc_param.awb.config.rgbs_thr_r = threshold(1.0); params->acc_param.awb.config.rgbs_thr_gr = threshold(0.9); params->acc_param.awb.config.rgbs_thr_gb = threshold(0.9); params->acc_param.awb.config.rgbs_thr_b = threshold(1.0); /* * Enable saturation inclusion on thr_b for ImgU to update the * ipu3_uapi_awb_set_item->sat_ratio field. */ params->acc_param.awb.config.rgbs_thr_b |= IPU3_UAPI_AWB_RGBS_THR_B_INCL_SAT | IPU3_UAPI_AWB_RGBS_THR_B_EN; const ipu3_uapi_grid_config &grid = context.configuration.grid.bdsGrid; params->acc_param.awb.config.grid = context.configuration.grid.bdsGrid; /* * Optical center is column start (respectively row start) of the * cell of interest minus its X center (respectively Y center). * * For the moment use BDS as a first approximation, but it should * be calculated based on Shading (SHD) parameters. */ params->acc_param.bnr = imguCssBnrDefaults; Size &bdsOutputSize = context.configuration.grid.bdsOutputSize; params->acc_param.bnr.column_size = bdsOutputSize.width; params->acc_param.bnr.opt_center.x_reset = grid.x_start - (bdsOutputSize.width / 2); params->acc_param.bnr.opt_center.y_reset = grid.y_start - (bdsOutputSize.height / 2); params->acc_param.bnr.opt_center_sqr.x_sqr_reset = params->acc_param.bnr.opt_center.x_reset * params->acc_param.bnr.opt_center.x_reset; params->acc_param.bnr.opt_center_sqr.y_sqr_reset = params->acc_param.bnr.opt_center.y_reset * params->acc_param.bnr.opt_center.y_reset; /* Convert to u3.13 fixed point values */ params->acc_param.bnr.wb_gains.gr = 8192 * context.frameContext.awb.gains.green; params->acc_param.bnr.wb_gains.r = 8192 * context.frameContext.awb.gains.red; params->acc_param.bnr.wb_gains.b = 8192 * context.frameContext.awb.gains.blue; params->acc_param.bnr.wb_gains.gb = 8192 * context.frameContext.awb.gains.green; LOG(IPU3Awb, Debug) << "Color temperature estimated: " << asyncResults_.temperatureK; /* The CCM matrix may change when color temperature will be used */ params->acc_param.ccm = imguCssCcmDefault; params->use.acc_awb = 1; params->use.acc_bnr = 1; params->use.acc_ccm = 1; } } /* namespace ipa::ipu3::algorithms */ } /* namespace libcamera */ 08' href='#n408'>408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357

/*
 * Copyright 2011 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef DRM_FOURCC_H
#define DRM_FOURCC_H

#include "drm.h"

#if defined(__cplusplus)
extern "C" {
#endif

/**
 * DOC: overview
 *
 * In the DRM subsystem, framebuffer pixel formats are described using the
 * fourcc codes defined in `include/uapi/drm/drm_fourcc.h`. In addition to the
 * fourcc code, a Format Modifier may optionally be provided, in order to
 * further describe the buffer's format - for example tiling or compression.
 *
 * Format Modifiers
 * ----------------
 *
 * Format modifiers are used in conjunction with a fourcc code, forming a
 * unique fourcc:modifier pair. This format:modifier pair must fully define the
 * format and data layout of the buffer, and should be the only way to describe
 * that particular buffer.
 *
 * Having multiple fourcc:modifier pairs which describe the same layout should
 * be avoided, as such aliases run the risk of different drivers exposing
 * different names for the same data format, forcing userspace to understand
 * that they are aliases.
 *
 * Format modifiers may change any property of the buffer, including the number
 * of planes and/or the required allocation size. Format modifiers are
 * vendor-namespaced, and as such the relationship between a fourcc code and a
 * modifier is specific to the modifer being used. For example, some modifiers
 * may preserve meaning - such as number of planes - from the fourcc code,
 * whereas others may not.
 *
 * Modifiers must uniquely encode buffer layout. In other words, a buffer must
 * match only a single modifier. A modifier must not be a subset of layouts of
 * another modifier. For instance, it's incorrect to encode pitch alignment in
 * a modifier: a buffer may match a 64-pixel aligned modifier and a 32-pixel
 * aligned modifier. That said, modifiers can have implicit minimal
 * requirements.
 *
 * For modifiers where the combination of fourcc code and modifier can alias,
 * a canonical pair needs to be defined and used by all drivers. Preferred
 * combinations are also encouraged where all combinations might lead to
 * confusion and unnecessarily reduced interoperability. An example for the
 * latter is AFBC, where the ABGR layouts are preferred over ARGB layouts.
 *
 * There are two kinds of modifier users:
 *
 * - Kernel and user-space drivers: for drivers it's important that modifiers
 *   don't alias, otherwise two drivers might support the same format but use
 *   different aliases, preventing them from sharing buffers in an efficient
 *   format.
 * - Higher-level programs interfacing with KMS/GBM/EGL/Vulkan/etc: these users
 *   see modifiers as opaque tokens they can check for equality and intersect.
 *   These users musn't need to know to reason about the modifier value
 *   (i.e. they are not expected to extract information out of the modifier).
 *
 * Vendors should document their modifier usage in as much detail as
 * possible, to ensure maximum compatibility across devices, drivers and
 * applications.
 *
 * The authoritative list of format modifier codes is found in
 * `include/uapi/drm/drm_fourcc.h`
 */

#define fourcc_code(a, b, c, d) ((__u32)(a) | ((__u32)(b) << 8) | \
				 ((__u32)(c) << 16) | ((__u32)(d) << 24))

#define DRM_FORMAT_BIG_ENDIAN (1U<<31) /* format is big endian instead of little endian */

/* Reserve 0 for the invalid format specifier */
#define DRM_FORMAT_INVALID	0

/* color index */
#define DRM_FORMAT_C8		fourcc_code('C', '8', ' ', ' ') /* [7:0] C */

/* 8 bpp Red */
#define DRM_FORMAT_R8		fourcc_code('R', '8', ' ', ' ') /* [7:0] R */

/* 16 bpp Red */
#define DRM_FORMAT_R16		fourcc_code('R', '1', '6', ' ') /* [15:0] R little endian */

/* 16 bpp RG */
#define DRM_FORMAT_RG88		fourcc_code('R', 'G', '8', '8') /* [15:0] R:G 8:8 little endian */
#define DRM_FORMAT_GR88		fourcc_code('G', 'R', '8', '8') /* [15:0] G:R 8:8 little endian */

/* 32 bpp RG */
#define DRM_FORMAT_RG1616	fourcc_code('R', 'G', '3', '2') /* [31:0] R:G 16:16 little endian */
#define DRM_FORMAT_GR1616	fourcc_code('G', 'R', '3', '2') /* [31:0] G:R 16:16 little endian */

/* 8 bpp RGB */
#define DRM_FORMAT_RGB332	fourcc_code('R', 'G', 'B', '8') /* [7:0] R:G:B 3:3:2 */
#define DRM_FORMAT_BGR233	fourcc_code('B', 'G', 'R', '8') /* [7:0] B:G:R 2:3:3 */

/* 16 bpp RGB */
#define DRM_FORMAT_XRGB4444	fourcc_code('X', 'R', '1', '2') /* [15:0] x:R:G:B 4:4:4:4 little endian */
#define DRM_FORMAT_XBGR4444	fourcc_code('X', 'B', '1', '2') /* [15:0] x:B:G:R 4:4:4:4 little endian */
#define DRM_FORMAT_RGBX4444	fourcc_code('R', 'X', '1', '2') /* [15:0] R:G:B:x 4:4:4:4 little endian */
#define DRM_FORMAT_BGRX4444	fourcc_code('B', 'X', '1', '2') /* [15:0] B:G:R:x 4:4:4:4 little endian */

#define DRM_FORMAT_ARGB4444	fourcc_code('A', 'R', '1', '2') /* [15:0] A:R:G:B 4:4:4:4 little endian */
#define DRM_FORMAT_ABGR4444	fourcc_code('A', 'B', '1', '2') /* [15:0] A:B:G:R 4:4:4:4 little endian */
#define DRM_FORMAT_RGBA4444	fourcc_code('R', 'A', '1', '2') /* [15:0] R:G:B:A 4:4:4:4 little endian */
#define DRM_FORMAT_BGRA4444	fourcc_code('B', 'A', '1', '2') /* [15:0] B:G:R:A 4:4:4:4 little endian */

#define DRM_FORMAT_XRGB1555	fourcc_code('X', 'R', '1', '5') /* [15:0] x:R:G:B 1:5:5:5 little endian */
#define DRM_FORMAT_XBGR1555	fourcc_code('X', 'B', '1', '5') /* [15:0] x:B:G:R 1:5:5:5 little endian */
#define DRM_FORMAT_RGBX5551	fourcc_code('R', 'X', '1', '5') /* [15:0] R:G:B:x 5:5:5:1 little endian */
#define DRM_FORMAT_BGRX5551	fourcc_code('B', 'X', '1', '5') /* [15:0] B:G:R:x 5:5:5:1 little endian */

#define DRM_FORMAT_ARGB1555	fourcc_code('A', 'R', '1', '5') /* [15:0] A:R:G:B 1:5:5:5 little endian */
#define DRM_FORMAT_ABGR1555	fourcc_code('A', 'B', '1', '5') /* [15:0] A:B:G:R 1:5:5:5 little endian */
#define DRM_FORMAT_RGBA5551	fourcc_code('R', 'A', '1', '5') /* [15:0] R:G:B:A 5:5:5:1 little endian */
#define DRM_FORMAT_BGRA5551	fourcc_code('B', 'A', '1', '5') /* [15:0] B:G:R:A 5:5:5:1 little endian */

#define DRM_FORMAT_RGB565	fourcc_code('R', 'G', '1', '6') /* [15:0] R:G:B 5:6:5 little endian */
#define DRM_FORMAT_BGR565	fourcc_code('B', 'G', '1', '6') /* [15:0] B:G:R 5:6:5 little endian */

/* 24 bpp RGB */
#define DRM_FORMAT_RGB888	fourcc_code('R', 'G', '2', '4') /* [23:0] R:G:B little endian */
#define DRM_FORMAT_BGR888	fourcc_code('B', 'G', '2', '4') /* [23:0] B:G:R little endian */

/* 32 bpp RGB */
#define DRM_FORMAT_XRGB8888	fourcc_code('X', 'R', '2', '4') /* [31:0] x:R:G:B 8:8:8:8 little endian */
#define DRM_FORMAT_XBGR8888	fourcc_code('X', 'B', '2', '4') /* [31:0] x:B:G:R 8:8:8:8 little endian */
#define DRM_FORMAT_RGBX8888	fourcc_code('R', 'X', '2', '4') /* [31:0] R:G:B:x 8:8:8:8 little endian */
#define DRM_FORMAT_BGRX8888	fourcc_code('B', 'X', '2', '4') /* [31:0] B:G:R:x 8:8:8:8 little endian */

#define DRM_FORMAT_ARGB8888	fourcc_code('A', 'R', '2', '4') /* [31:0] A:R:G:B 8:8:8:8 little endian */
#define DRM_FORMAT_ABGR8888	fourcc_code('A', 'B', '2', '4') /* [31:0] A:B:G:R 8:8:8:8 little endian */
#define DRM_FORMAT_RGBA8888	fourcc_code('R', 'A', '2', '4') /* [31:0] R:G:B:A 8:8:8:8 little endian */
#define DRM_FORMAT_BGRA8888	fourcc_code('B', 'A', '2', '4') /* [31:0] B:G:R:A 8:8:8:8 little endian */

#define DRM_FORMAT_XRGB2101010	fourcc_code('X', 'R', '3', '0') /* [31:0] x:R:G:B 2:10:10:10 little endian */
#define DRM_FORMAT_XBGR2101010	fourcc_code('X', 'B', '3', '0') /* [31:0] x:B:G:R 2:10:10:10 little endian */
#define DRM_FORMAT_RGBX1010102	fourcc_code('R', 'X', '3', '0') /* [31:0] R:G:B:x 10:10:10:2 little endian */
#define DRM_FORMAT_BGRX1010102	fourcc_code('B', 'X', '3', '0') /* [31:0] B:G:R:x 10:10:10:2 little endian */

#define DRM_FORMAT_ARGB2101010	fourcc_code('A', 'R', '3', '0') /* [31:0] A:R:G:B 2:10:10:10 little endian */
#define DRM_FORMAT_ABGR2101010	fourcc_code('A', 'B', '3', '0') /* [31:0] A:B:G:R 2:10:10:10 little endian */
#define DRM_FORMAT_RGBA1010102	fourcc_code('R', 'A', '3', '0') /* [31:0] R:G:B:A 10:10:10:2 little endian */
#define DRM_FORMAT_BGRA1010102	fourcc_code('B', 'A', '3', '0') /* [31:0] B:G:R:A 10:10:10:2 little endian */

/*
 * Floating point 64bpp RGB
 * IEEE 754-2008 binary16 half-precision float
 * [15:0] sign:exponent:mantissa 1:5:10
 */
#define DRM_FORMAT_XRGB16161616F fourcc_code('X', 'R', '4', 'H') /* [63:0] x:R:G:B 16:16:16:16 little endian */
#define DRM_FORMAT_XBGR16161616F fourcc_code('X', 'B', '4', 'H') /* [63:0] x:B:G:R 16:16:16:16 little endian */

#define DRM_FORMAT_ARGB16161616F fourcc_code('A', 'R', '4', 'H') /* [63:0] A:R:G:B 16:16:16:16 little endian */
#define DRM_FORMAT_ABGR16161616F fourcc_code('A', 'B', '4', 'H') /* [63:0] A:B:G:R 16:16:16:16 little endian */

/*
 * RGBA format with 10-bit components packed in 64-bit per pixel, with 6 bits
 * of unused padding per component:
 */
#define DRM_FORMAT_AXBXGXRX106106106106 fourcc_code('A', 'B', '1', '0') /* [63:0] A:x:B:x:G:x:R:x 10:6:10:6:10:6:10:6 little endian */

/* packed YCbCr */
#define DRM_FORMAT_YUYV		fourcc_code('Y', 'U', 'Y', 'V') /* [31:0] Cr0:Y1:Cb0:Y0 8:8:8:8 little endian */
#define DRM_FORMAT_YVYU		fourcc_code('Y', 'V', 'Y', 'U') /* [31:0] Cb0:Y1:Cr0:Y0 8:8:8:8 little endian */
#define DRM_FORMAT_UYVY		fourcc_code('U', 'Y', 'V', 'Y') /* [31:0] Y1:Cr0:Y0:Cb0 8:8:8:8 little endian */
#define DRM_FORMAT_VYUY		fourcc_code('V', 'Y', 'U', 'Y') /* [31:0] Y1:Cb0:Y0:Cr0 8:8:8:8 little endian */

#define DRM_FORMAT_AYUV		fourcc_code('A', 'Y', 'U', 'V') /* [31:0] A:Y:Cb:Cr 8:8:8:8 little endian */
#define DRM_FORMAT_XYUV8888	fourcc_code('X', 'Y', 'U', 'V') /* [31:0] X:Y:Cb:Cr 8:8:8:8 little endian */
#define DRM_FORMAT_VUY888	fourcc_code('V', 'U', '2', '4') /* [23:0] Cr:Cb:Y 8:8:8 little endian */
#define DRM_FORMAT_VUY101010	fourcc_code('V', 'U', '3', '0') /* Y followed by U then V, 10:10:10. Non-linear modifier only */

/*
 * packed Y2xx indicate for each component, xx valid data occupy msb
 * 16-xx padding occupy lsb
 */
#define DRM_FORMAT_Y210         fourcc_code('Y', '2', '1', '0') /* [63:0] Cr0:0:Y1:0:Cb0:0:Y0:0 10:6:10:6:10:6:10:6 little endian per 2 Y pixels */
#define DRM_FORMAT_Y212         fourcc_code('Y', '2', '1', '2') /* [63:0] Cr0:0:Y1:0:Cb0:0:Y0:0 12:4:12:4:12:4:12:4 little endian per 2 Y pixels */
#define DRM_FORMAT_Y216         fourcc_code('Y', '2', '1', '6') /* [63:0] Cr0:Y1:Cb0:Y0 16:16:16:16 little endian per 2 Y pixels */

/*
 * packed Y4xx indicate for each component, xx valid data occupy msb
 * 16-xx padding occupy lsb except Y410
 */
#define DRM_FORMAT_Y410         fourcc_code('Y', '4', '1', '0') /* [31:0] A:Cr:Y:Cb 2:10:10:10 little endian */
#define DRM_FORMAT_Y412         fourcc_code('Y', '4', '1', '2') /* [63:0] A:0:Cr:0:Y:0:Cb:0 12:4:12:4:12:4:12:4 little endian */
#define DRM_FORMAT_Y416         fourcc_code('Y', '4', '1', '6') /* [63:0] A:Cr:Y:Cb 16:16:16:16 little endian */

#define DRM_FORMAT_XVYU2101010	fourcc_code('X', 'V', '3', '0') /* [31:0] X:Cr:Y:Cb 2:10:10:10 little endian */
#define DRM_FORMAT_XVYU12_16161616	fourcc_code('X', 'V', '3', '6') /* [63:0] X:0:Cr:0:Y:0:Cb:0 12:4:12:4:12:4:12:4 little endian */
#define DRM_FORMAT_XVYU16161616	fourcc_code('X', 'V', '4', '8') /* [63:0] X:Cr:Y:Cb 16:16:16:16 little endian */

/*
 * packed YCbCr420 2x2 tiled formats
 * first 64 bits will contain Y,Cb,Cr components for a 2x2 tile
 */
/* [63:0]   A3:A2:Y3:0:Cr0:0:Y2:0:A1:A0:Y1:0:Cb0:0:Y0:0  1:1:8:2:8:2:8:2:1:1:8:2:8:2:8:2 little endian */
#define DRM_FORMAT_Y0L0		fourcc_code('Y', '0', 'L', '0')
/* [63:0]   X3:X2:Y3:0:Cr0:0:Y2:0:X1:X0:Y1:0:Cb0:0:Y0:0  1:1:8:2:8:2:8:2:1:1:8:2:8:2:8:2 little endian */
#define DRM_FORMAT_X0L0		fourcc_code('X', '0', 'L', '0')

/* [63:0]   A3:A2:Y3:Cr0:Y2:A1:A0:Y1:Cb0:Y0  1:1:10:10:10:1:1:10:10:10 little endian */
#define DRM_FORMAT_Y0L2		fourcc_code('Y', '0', 'L', '2')
/* [63:0]   X3:X2:Y3:Cr0:Y2:X1:X0:Y1:Cb0:Y0  1:1:10:10:10:1:1:10:10:10 little endian */
#define DRM_FORMAT_X0L2		fourcc_code('X', '0', 'L', '2')

/*
 * 1-plane YUV 4:2:0
 * In these formats, the component ordering is specified (Y, followed by U
 * then V), but the exact Linear layout is undefined.
 * These formats can only be used with a non-Linear modifier.
 */
#define DRM_FORMAT_YUV420_8BIT	fourcc_code('Y', 'U', '0', '8')
#define DRM_FORMAT_YUV420_10BIT	fourcc_code('Y', 'U', '1', '0')

/*
 * 2 plane RGB + A
 * index 0 = RGB plane, same format as the corresponding non _A8 format has
 * index 1 = A plane, [7:0] A
 */
#define DRM_FORMAT_XRGB8888_A8	fourcc_code('X', 'R', 'A', '8')
#define DRM_FORMAT_XBGR8888_A8	fourcc_code('X', 'B', 'A', '8')
#define DRM_FORMAT_RGBX8888_A8	fourcc_code('R', 'X', 'A', '8')
#define DRM_FORMAT_BGRX8888_A8	fourcc_code('B', 'X', 'A', '8')
#define DRM_FORMAT_RGB888_A8	fourcc_code('R', '8', 'A', '8')
#define DRM_FORMAT_BGR888_A8	fourcc_code('B', '8', 'A', '8')
#define DRM_FORMAT_RGB565_A8	fourcc_code('R', '5', 'A', '8')