1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 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 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
|
// SPDX-License-Identifier: Apache-2.0
// ----------------------------------------------------------------------------
// Copyright 2011-2025 Arm Limited
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy
// of the License at:
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
// ----------------------------------------------------------------------------
#if !defined(ASTCENC_DECOMPRESS_ONLY)
/**
* @brief Functions to compress a symbolic block.
*/
#include "astcenc_internal.h"
#include "astcenc_diagnostic_trace.h"
#include <cassert>
/**
* @brief Merge two planes of endpoints into a single vector.
*
* @param ep_plane1 The endpoints for plane 1.
* @param ep_plane2 The endpoints for plane 2.
* @param component_plane2 The color component for plane 2.
* @param[out] result The merged output.
*/
static void merge_endpoints(
const endpoints& ep_plane1,
const endpoints& ep_plane2,
unsigned int component_plane2,
endpoints& result
) {
unsigned int partition_count = ep_plane1.partition_count;
assert(partition_count == 1);
vmask4 sep_mask = vint4::lane_id() == vint4(component_plane2);
result.partition_count = partition_count;
result.endpt0[0] = select(ep_plane1.endpt0[0], ep_plane2.endpt0[0], sep_mask);
result.endpt1[0] = select(ep_plane1.endpt1[0], ep_plane2.endpt1[0], sep_mask);
}
/**
* @brief Attempt to improve weights given a chosen configuration.
*
* Given a fixed weight grid decimation and weight value quantization, iterate over all weights (per
* partition and per plane) and attempt to improve image quality by moving each weight up by one or
* down by one quantization step.
*
* This is a specialized function which only supports operating on undecimated weight grids,
* therefore primarily improving the performance of 4x4 and 5x5 blocks where grid decimation
* is needed less often.
*
* @param decode_mode The decode mode (LDR, HDR).
* @param bsd The block size information.
* @param blk The image block color data to compress.
* @param[out] scb The symbolic compressed block output.
*/
static bool realign_weights_undecimated(
astcenc_profile decode_mode,
const block_size_descriptor& bsd,
const image_block& blk,
symbolic_compressed_block& scb
) {
// Get the partition descriptor
unsigned int partition_count = scb.partition_count;
const auto& pi = bsd.get_partition_info(partition_count, scb.partition_index);
// Get the quantization table
const block_mode& bm = bsd.get_block_mode(scb.block_mode);
unsigned int weight_quant_level = bm.quant_mode;
const quant_and_transfer_table& qat = quant_and_xfer_tables[weight_quant_level];
unsigned int max_plane = bm.is_dual_plane;
int plane2_component = scb.plane2_component;
vmask4 plane_mask = vint4::lane_id() == vint4(plane2_component);
// Decode the color endpoints
bool rgb_hdr;
bool alpha_hdr;
vint4 endpnt0[BLOCK_MAX_PARTITIONS];
vint4 endpnt1[BLOCK_MAX_PARTITIONS];
vfloat4 endpnt0f[BLOCK_MAX_PARTITIONS];
vfloat4 offset[BLOCK_MAX_PARTITIONS];
promise(partition_count > 0);
for (unsigned int pa_idx = 0; pa_idx < partition_count; pa_idx++)
{
unpack_color_endpoints(decode_mode,
scb.color_formats[pa_idx],
scb.color_values[pa_idx],
rgb_hdr, alpha_hdr,
endpnt0[pa_idx],
endpnt1[pa_idx]);
}
uint8_t* dec_weights_uquant = scb.weights;
bool adjustments = false;
// For each plane and partition ...
for (unsigned int pl_idx = 0; pl_idx <= max_plane; pl_idx++)
{
for (unsigned int pa_idx = 0; pa_idx < partition_count; pa_idx++)
{
// Compute the endpoint delta for all components in current plane
vint4 epd = endpnt1[pa_idx] - endpnt0[pa_idx];
epd = select(epd, vint4::zero(), plane_mask);
endpnt0f[pa_idx] = int_to_float(endpnt0[pa_idx]);
offset[pa_idx] = int_to_float(epd) * (1.0f / 64.0f);
}
// For each weight compute previous, current, and next errors
promise(bsd.texel_count > 0);
for (unsigned int texel = 0; texel < bsd.texel_count; texel++)
{
int uqw = dec_weights_uquant[texel];
uint32_t prev_and_next = qat.prev_next_values[uqw];
int uqw_down = prev_and_next & 0xFF;
int uqw_up = (prev_and_next >> 8) & 0xFF;
// Interpolate the colors to create the diffs
float weight_base = static_cast<float>(uqw);
float weight_down = static_cast<float>(uqw_down - uqw);
float weight_up = static_cast<float>(uqw_up - uqw);
unsigned int partition = pi.partition_of_texel[texel];
vfloat4 color_offset = offset[partition];
vfloat4 color_base = endpnt0f[partition];
vfloat4 color = color_base + color_offset * weight_base;
vfloat4 orig_color = blk.texel(texel);
vfloat4 error_weight = blk.channel_weight;
vfloat4 color_diff = color - orig_color;
vfloat4 color_diff_down = color_diff + color_offset * weight_down;
vfloat4 color_diff_up = color_diff + color_offset * weight_up;
float error_base = dot_s(color_diff * color_diff, error_weight);
float error_down = dot_s(color_diff_down * color_diff_down, error_weight);
float error_up = dot_s(color_diff_up * color_diff_up, error_weight);
// Check if the prev or next error is better, and if so use it
if ((error_up < error_base) && (error_up < error_down) && (uqw < 64))
{
dec_weights_uquant[texel] = static_cast<uint8_t>(uqw_up);
adjustments = true;
}
else if ((error_down < error_base) && (uqw > 0))
{
dec_weights_uquant[texel] = static_cast<uint8_t>(uqw_down);
adjustments = true;
}
}
// Prepare iteration for plane 2
dec_weights_uquant += WEIGHTS_PLANE2_OFFSET;
plane_mask = ~plane_mask;
}
return adjustments;
}
/**
* @brief Attempt to improve weights given a chosen configuration.
*
* Given a fixed weight grid decimation and weight value quantization, iterate over all weights (per
* partition and per plane) and attempt to improve image quality by moving each weight up by one or
* down by one quantization step.
*
* @param decode_mode The decode mode (LDR, HDR).
* @param bsd The block size information.
* @param blk The image block color data to compress.
* @param[out] scb The symbolic compressed block output.
*/
static bool realign_weights_decimated(
astcenc_profile decode_mode,
const block_size_descriptor& bsd,
const image_block& blk,
symbolic_compressed_block& scb
) {
// Get the partition descriptor
unsigned int partition_count = scb.partition_count;
const auto& pi = bsd.get_partition_info(partition_count, scb.partition_index);
// Get the quantization table
const block_mode& bm = bsd.get_block_mode(scb.block_mode);
unsigned int weight_quant_level = bm.quant_mode;
const quant_and_transfer_table& qat = quant_and_xfer_tables[weight_quant_level];
// Get the decimation table
const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
unsigned int weight_count = di.weight_count;
assert(weight_count != bsd.texel_count);
unsigned int max_plane = bm.is_dual_plane;
int plane2_component = scb.plane2_component;
vmask4 plane_mask = vint4::lane_id() == vint4(plane2_component);
// Decode the color endpoints
bool rgb_hdr;
bool alpha_hdr;
vint4 endpnt0[BLOCK_MAX_PARTITIONS];
vint4 endpnt1[BLOCK_MAX_PARTITIONS];
vfloat4 endpnt0f[BLOCK_MAX_PARTITIONS];
vfloat4 offset[BLOCK_MAX_PARTITIONS];
promise(partition_count > 0);
promise(weight_count > 0);
for (unsigned int pa_idx = 0; pa_idx < partition_count; pa_idx++)
{
unpack_color_endpoints(decode_mode,
scb.color_formats[pa_idx],
scb.color_values[pa_idx],
rgb_hdr, alpha_hdr,
endpnt0[pa_idx],
endpnt1[pa_idx]);
}
uint8_t* dec_weights_uquant = scb.weights;
bool adjustments = false;
// For each plane and partition ...
for (unsigned int pl_idx = 0; pl_idx <= max_plane; pl_idx++)
{
for (unsigned int pa_idx = 0; pa_idx < partition_count; pa_idx++)
{
// Compute the endpoint delta for all components in current plane
vint4 epd = endpnt1[pa_idx] - endpnt0[pa_idx];
epd = select(epd, vint4::zero(), plane_mask);
endpnt0f[pa_idx] = int_to_float(endpnt0[pa_idx]);
offset[pa_idx] = int_to_float(epd) * (1.0f / 64.0f);
}
// Create an unquantized weight grid for this decimation level
ASTCENC_ALIGNAS float uq_weightsf[BLOCK_MAX_WEIGHTS];
for (unsigned int we_idx = 0; we_idx < weight_count; we_idx += ASTCENC_SIMD_WIDTH)
{
vint unquant_value(dec_weights_uquant + we_idx);
vfloat unquant_valuef = int_to_float(unquant_value);
storea(unquant_valuef, uq_weightsf + we_idx);
}
// For each weight compute previous, current, and next errors
for (unsigned int we_idx = 0; we_idx < weight_count; we_idx++)
{
int uqw = dec_weights_uquant[we_idx];
uint32_t prev_and_next = qat.prev_next_values[uqw];
float uqw_base = uq_weightsf[we_idx];
float uqw_down = static_cast<float>(prev_and_next & 0xFF);
float uqw_up = static_cast<float>((prev_and_next >> 8) & 0xFF);
float uqw_diff_down = uqw_down - uqw_base;
float uqw_diff_up = uqw_up - uqw_base;
vfloat4 error_basev = vfloat4::zero();
vfloat4 error_downv = vfloat4::zero();
vfloat4 error_upv = vfloat4::zero();
// Interpolate the colors to create the diffs
unsigned int texels_to_evaluate = di.weight_texel_count[we_idx];
promise(texels_to_evaluate > 0);
for (unsigned int te_idx = 0; te_idx < texels_to_evaluate; te_idx++)
{
unsigned int texel = di.weight_texels_tr[te_idx][we_idx];
float tw_base = di.texel_contrib_for_weight[te_idx][we_idx];
float weight_base = (uq_weightsf[di.texel_weights_tr[0][texel]] * di.texel_weight_contribs_float_tr[0][texel]
+ uq_weightsf[di.texel_weights_tr[1][texel]] * di.texel_weight_contribs_float_tr[1][texel])
+ (uq_weightsf[di.texel_weights_tr[2][texel]] * di.texel_weight_contribs_float_tr[2][texel]
+ uq_weightsf[di.texel_weights_tr[3][texel]] * di.texel_weight_contribs_float_tr[3][texel]);
// Ideally this is integer rounded, but IQ gain it isn't worth the overhead
// float weight = astc::flt_rd(weight_base + 0.5f);
// float weight_down = astc::flt_rd(weight_base + 0.5f + uqw_diff_down * tw_base) - weight;
// float weight_up = astc::flt_rd(weight_base + 0.5f + uqw_diff_up * tw_base) - weight;
float weight_down = weight_base + uqw_diff_down * tw_base - weight_base;
float weight_up = weight_base + uqw_diff_up * tw_base - weight_base;
unsigned int partition = pi.partition_of_texel[texel];
vfloat4 color_offset = offset[partition];
vfloat4 color_base = endpnt0f[partition];
vfloat4 color = color_base + color_offset * weight_base;
vfloat4 orig_color = blk.texel(texel);
vfloat4 color_diff = color - orig_color;
vfloat4 color_down_diff = color_diff + color_offset * weight_down;
vfloat4 color_up_diff = color_diff + color_offset * weight_up;
error_basev += color_diff * color_diff;
error_downv += color_down_diff * color_down_diff;
error_upv += color_up_diff * color_up_diff;
}
vfloat4 error_weight = blk.channel_weight;
float error_base = hadd_s(error_basev * error_weight);
float error_down = hadd_s(error_downv * error_weight);
float error_up = hadd_s(error_upv * error_weight);
// Check if the prev or next error is better, and if so use it
if ((error_up < error_base) && (error_up < error_down) && (uqw < 64))
{
uq_weightsf[we_idx] = uqw_up;
dec_weights_uquant[we_idx] = static_cast<uint8_t>(uqw_up);
adjustments = true;
}
else if ((error_down < error_base) && (uqw > 0))
{
uq_weightsf[we_idx] = uqw_down;
dec_weights_uquant[we_idx] = static_cast<uint8_t>(uqw_down);
adjustments = true;
}
}
// Prepare iteration for plane 2
dec_weights_uquant += WEIGHTS_PLANE2_OFFSET;
plane_mask = ~plane_mask;
}
return adjustments;
}
/**
* @brief Compress a block using a chosen partitioning and 1 plane of weights.
*
* @param config The compressor configuration.
* @param bsd The block size information.
* @param blk The image block color data to compress.
* @param only_always True if we only use "always" percentile block modes.
* @param tune_errorval_threshold The error value threshold.
* @param partition_count The partition count.
* @param partition_index The partition index if @c partition_count is 2-4.
* @param[out] scb The symbolic compressed block output.
* @param[out] tmpbuf The quantized weights for plane 1.
*/
static float compress_symbolic_block_for_partition_1plane(
const astcenc_config& config,
const block_size_descriptor& bsd,
const image_block& blk,
bool only_always,
float tune_errorval_threshold,
unsigned int partition_count,
unsigned int partition_index,
symbolic_compressed_block& scb,
compression_working_buffers& tmpbuf,
int quant_limit
) {
promise(partition_count > 0);
promise(config.tune_candidate_limit > 0);
promise(config.tune_refinement_limit > 0);
int max_weight_quant = astc::min(static_cast<int>(QUANT_32), quant_limit);
auto compute_difference = &compute_symbolic_block_difference_1plane;
if ((partition_count == 1) && !(config.flags & ASTCENC_FLG_MAP_RGBM))
{
compute_difference = &compute_symbolic_block_difference_1plane_1partition;
}
const auto& pi = bsd.get_partition_info(partition_count, partition_index);
// Compute ideal weights and endpoint colors, with no quantization or decimation
endpoints_and_weights& ei = tmpbuf.ei1;
compute_ideal_colors_and_weights_1plane(blk, pi, ei);
// Compute ideal weights and endpoint colors for every decimation
float* dec_weights_ideal = tmpbuf.dec_weights_ideal;
uint8_t* dec_weights_uquant = tmpbuf.dec_weights_uquant;
// For each decimation mode, compute an ideal set of weights with no quantization
unsigned int max_decimation_modes = only_always ? bsd.decimation_mode_count_always
: bsd.decimation_mode_count_selected;
promise(max_decimation_modes > 0);
for (unsigned int i = 0; i < max_decimation_modes; i++)
{
const auto& dm = bsd.get_decimation_mode(i);
if (!dm.is_ref_1plane(static_cast<quant_method>(max_weight_quant)))
{
continue;
}
const auto& di = bsd.get_decimation_info(i);
compute_ideal_weights_for_decimation(
ei,
di,
dec_weights_ideal + i * BLOCK_MAX_WEIGHTS);
}
// Compute maximum colors for the endpoints and ideal weights, then for each endpoint and ideal
// weight pair, compute the smallest weight that will result in a color value greater than 1
vfloat4 min_ep(10.0f);
for (unsigned int i = 0; i < partition_count; i++)
{
vfloat4 ep = (vfloat4(1.0f) - ei.ep.endpt0[i]) / (ei.ep.endpt1[i] - ei.ep.endpt0[i]);
vmask4 use_ep = (ep > vfloat4(0.5f)) & (ep < min_ep);
min_ep = select(min_ep, ep, use_ep);
}
float min_wt_cutoff = hmin_s(min_ep);
// For each mode, use the angular method to compute a shift
compute_angular_endpoints_1plane(
only_always, bsd, dec_weights_ideal, max_weight_quant, tmpbuf);
float* weight_low_value = tmpbuf.weight_low_value1;
float* weight_high_value = tmpbuf.weight_high_value1;
int8_t* qwt_bitcounts = tmpbuf.qwt_bitcounts;
float* qwt_errors = tmpbuf.qwt_errors;
// For each mode (which specifies a decimation and a quantization):
// * Compute number of bits needed for the quantized weights
// * Generate an optimized set of quantized weights
// * Compute quantization errors for the mode
static const int8_t free_bits_for_partition_count[4] {
115 - 4, 111 - 4 - PARTITION_INDEX_BITS, 108 - 4 - PARTITION_INDEX_BITS, 105 - 4 - PARTITION_INDEX_BITS
};
unsigned int max_block_modes = only_always ? bsd.block_mode_count_1plane_always
: bsd.block_mode_count_1plane_selected;
promise(max_block_modes > 0);
for (unsigned int i = 0; i < max_block_modes; i++)
{
const block_mode& bm = bsd.block_modes[i];
if (bm.quant_mode > max_weight_quant)
{
qwt_errors[i] = 1e38f;
continue;
}
assert(!bm.is_dual_plane);
int bitcount = free_bits_for_partition_count[partition_count - 1] - bm.weight_bits;
if (bitcount <= 0)
{
qwt_errors[i] = 1e38f;
continue;
}
if (weight_high_value[i] > 1.02f * min_wt_cutoff)
{
weight_high_value[i] = 1.0f;
}
int decimation_mode = bm.decimation_mode;
const auto& di = bsd.get_decimation_info(decimation_mode);
qwt_bitcounts[i] = static_cast<int8_t>(bitcount);
ASTCENC_ALIGNAS float dec_weights_uquantf[BLOCK_MAX_WEIGHTS];
// Generate the optimized set of weights for the weight mode
compute_quantized_weights_for_decimation(
di,
weight_low_value[i], weight_high_value[i],
dec_weights_ideal + BLOCK_MAX_WEIGHTS * decimation_mode,
dec_weights_uquantf,
dec_weights_uquant + BLOCK_MAX_WEIGHTS * i,
bm.get_weight_quant_mode());
// Compute weight quantization errors for the block mode
qwt_errors[i] = compute_error_of_weight_set_1plane(
ei,
di,
dec_weights_uquantf);
}
// Decide the optimal combination of color endpoint encodings and weight encodings
uint8_t partition_format_specifiers[TUNE_MAX_TRIAL_CANDIDATES][BLOCK_MAX_PARTITIONS];
int block_mode_index[TUNE_MAX_TRIAL_CANDIDATES];
quant_method color_quant_level[TUNE_MAX_TRIAL_CANDIDATES];
quant_method color_quant_level_mod[TUNE_MAX_TRIAL_CANDIDATES];
unsigned int candidate_count = compute_ideal_endpoint_formats(
pi, blk, ei.ep, qwt_bitcounts, qwt_errors,
config.tune_candidate_limit, 0, max_block_modes,
partition_format_specifiers, block_mode_index,
color_quant_level, color_quant_level_mod, tmpbuf);
// Iterate over the N believed-to-be-best modes to find out which one is actually best
float best_errorval_in_mode = ERROR_CALC_DEFAULT;
float best_errorval_in_scb = scb.errorval;
for (unsigned int i = 0; i < candidate_count; i++)
{
TRACE_NODE(node0, "candidate");
const int bm_packed_index = block_mode_index[i];
assert(bm_packed_index >= 0 && bm_packed_index < static_cast<int>(bsd.block_mode_count_1plane_selected));
const block_mode& qw_bm = bsd.block_modes[bm_packed_index];
int decimation_mode = qw_bm.decimation_mode;
const auto& di = bsd.get_decimation_info(decimation_mode);
promise(di.weight_count > 0);
trace_add_data("weight_x", di.weight_x);
trace_add_data("weight_y", di.weight_y);
trace_add_data("weight_z", di.weight_z);
trace_add_data("weight_quant", qw_bm.quant_mode);
// Recompute the ideal color endpoints before storing them
vfloat4 rgbs_colors[BLOCK_MAX_PARTITIONS];
vfloat4 rgbo_colors[BLOCK_MAX_PARTITIONS];
symbolic_compressed_block workscb;
endpoints workep = ei.ep;
uint8_t* u8_weight_src = dec_weights_uquant + BLOCK_MAX_WEIGHTS * bm_packed_index;
for (unsigned int j = 0; j < di.weight_count; j++)
{
workscb.weights[j] = u8_weight_src[j];
}
for (unsigned int l = 0; l < config.tune_refinement_limit; l++)
{
recompute_ideal_colors_1plane(
blk, pi, di, workscb.weights,
workep, rgbs_colors, rgbo_colors);
// Quantize the chosen color, tracking if worth trying the mod value
bool all_same = color_quant_level[i] != color_quant_level_mod[i];
for (unsigned int j = 0; j < partition_count; j++)
{
workscb.color_formats[j] = pack_color_endpoints(
workep.endpt0[j],
workep.endpt1[j],
rgbs_colors[j],
rgbo_colors[j],
partition_format_specifiers[i][j],
workscb.color_values[j],
color_quant_level[i]);
all_same = all_same && workscb.color_formats[j] == workscb.color_formats[0];
}
// If all the color endpoint modes are the same, we get a few more bits to store colors;
// let's see if we can take advantage of this: requantize all the colors and see if the
// endpoint modes remain the same.
workscb.color_formats_matched = 0;
if (partition_count >= 2 && all_same)
{
uint8_t colorvals[BLOCK_MAX_PARTITIONS][8];
uint8_t color_formats_mod[BLOCK_MAX_PARTITIONS] { 0 };
bool all_same_mod = true;
for (unsigned int j = 0; j < partition_count; j++)
{
color_formats_mod[j] = pack_color_endpoints(
workep.endpt0[j],
workep.endpt1[j],
rgbs_colors[j],
rgbo_colors[j],
partition_format_specifiers[i][j],
colorvals[j],
color_quant_level_mod[i]);
// Early out as soon as it's no longer possible to use mod
if (color_formats_mod[j] != color_formats_mod[0])
{
all_same_mod = false;
break;
}
}
if (all_same_mod)
{
workscb.color_formats_matched = 1;
for (unsigned int j = 0; j < BLOCK_MAX_PARTITIONS; j++)
{
for (unsigned int k = 0; k < 8; k++)
{
workscb.color_values[j][k] = colorvals[j][k];
}
workscb.color_formats[j] = color_formats_mod[j];
}
}
}
// Store header fields
workscb.partition_count = static_cast<uint8_t>(partition_count);
workscb.partition_index = static_cast<uint16_t>(partition_index);
workscb.plane2_component = -1;
workscb.quant_mode = workscb.color_formats_matched ? color_quant_level_mod[i] : color_quant_level[i];
workscb.block_mode = qw_bm.mode_index;
workscb.block_type = SYM_BTYPE_NONCONST;
// Pre-realign test
if (l == 0)
{
float errorval = compute_difference(config, bsd, workscb, blk);
if (errorval == -ERROR_CALC_DEFAULT)
{
errorval = -errorval;
workscb.block_type = SYM_BTYPE_ERROR;
}
trace_add_data("error_prerealign", errorval);
best_errorval_in_mode = astc::min(errorval, best_errorval_in_mode);
// Average refinement improvement is 3.5% per iteration (allow 4.5%), but the first
// iteration can help more so we give it a extra 8% leeway. Use this knowledge to
// drive a heuristic to skip blocks that are unlikely to catch up with the best
// block we have already.
unsigned int iters_remaining = config.tune_refinement_limit - l;
float threshold = (0.045f * static_cast<float>(iters_remaining)) + 1.08f;
if (errorval > (threshold * best_errorval_in_scb))
{
break;
}
if (errorval < best_errorval_in_scb)
{
best_errorval_in_scb = errorval;
workscb.errorval = errorval;
scb = workscb;
if (errorval < tune_errorval_threshold)
{
// Skip remaining candidates - this is "good enough"
i = candidate_count;
break;
}
}
}
bool adjustments;
if (di.weight_count != bsd.texel_count)
{
adjustments = realign_weights_decimated(
config.profile, bsd, blk, workscb);
}
else
{
adjustments = realign_weights_undecimated(
config.profile, bsd, blk, workscb);
}
// Post-realign test
float errorval = compute_difference(config, bsd, workscb, blk);
if (errorval == -ERROR_CALC_DEFAULT)
{
errorval = -errorval;
workscb.block_type = SYM_BTYPE_ERROR;
}
trace_add_data("error_postrealign", errorval);
best_errorval_in_mode = astc::min(errorval, best_errorval_in_mode);
// Average refinement improvement is 3.5% per iteration, so skip blocks that are
// unlikely to catch up with the best block we have already. Assume a 4.5% per step to
// give benefit of the doubt ...
unsigned int iters_remaining = config.tune_refinement_limit - 1 - l;
float threshold = (0.045f * static_cast<float>(iters_remaining)) + 1.0f;
if (errorval > (threshold * best_errorval_in_scb))
{
break;
}
if (errorval < best_errorval_in_scb)
{
best_errorval_in_scb = errorval;
workscb.errorval = errorval;
scb = workscb;
if (errorval < tune_errorval_threshold)
{
// Skip remaining candidates - this is "good enough"
i = candidate_count;
break;
}
}
if (!adjustments)
{
break;
}
}
}
return best_errorval_in_mode;
}
/**
* @brief Compress a block using a chosen partitioning and 2 planes of weights.
*
* @param config The compressor configuration.
* @param bsd The block size information.
* @param blk The image block color data to compress.
* @param tune_errorval_threshold The error value threshold.
* @param plane2_component The component index for the second plane of weights.
* @param[out] scb The symbolic compressed block output.
* @param[out] tmpbuf The quantized weights for plane 1.
*/
static float compress_symbolic_block_for_partition_2planes(
const astcenc_config& config,
const block_size_descriptor& bsd,
const image_block& blk,
float tune_errorval_threshold,
unsigned int plane2_component,
symbolic_compressed_block& scb,
compression_working_buffers& tmpbuf,
int quant_limit
) {
promise(config.tune_candidate_limit > 0);
promise(config.tune_refinement_limit > 0);
promise(bsd.decimation_mode_count_selected > 0);
int max_weight_quant = astc::min(static_cast<int>(QUANT_32), quant_limit);
// Compute ideal weights and endpoint colors, with no quantization or decimation
endpoints_and_weights& ei1 = tmpbuf.ei1;
endpoints_and_weights& ei2 = tmpbuf.ei2;
compute_ideal_colors_and_weights_2planes(bsd, blk, plane2_component, ei1, ei2);
// Compute ideal weights and endpoint colors for every decimation
float* dec_weights_ideal = tmpbuf.dec_weights_ideal;
uint8_t* dec_weights_uquant = tmpbuf.dec_weights_uquant;
// For each decimation mode, compute an ideal set of weights with no quantization
for (unsigned int i = 0; i < bsd.decimation_mode_count_selected; i++)
{
const auto& dm = bsd.get_decimation_mode(i);
if (!dm.is_ref_2plane(static_cast<quant_method>(max_weight_quant)))
{
continue;
}
const auto& di = bsd.get_decimation_info(i);
compute_ideal_weights_for_decimation(
ei1,
di,
dec_weights_ideal + i * BLOCK_MAX_WEIGHTS);
compute_ideal_weights_for_decimation(
ei2,
di,
dec_weights_ideal + i * BLOCK_MAX_WEIGHTS + WEIGHTS_PLANE2_OFFSET);
}
// Compute maximum colors for the endpoints and ideal weights, then for each endpoint and ideal
// weight pair, compute the smallest weight that will result in a color value greater than 1
vfloat4 min_ep1(10.0f);
vfloat4 min_ep2(10.0f);
vfloat4 ep1 = (vfloat4(1.0f) - ei1.ep.endpt0[0]) / (ei1.ep.endpt1[0] - ei1.ep.endpt0[0]);
vmask4 use_ep1 = (ep1 > vfloat4(0.5f)) & (ep1 < min_ep1);
min_ep1 = select(min_ep1, ep1, use_ep1);
vfloat4 ep2 = (vfloat4(1.0f) - ei2.ep.endpt0[0]) / (ei2.ep.endpt1[0] - ei2.ep.endpt0[0]);
vmask4 use_ep2 = (ep2 > vfloat4(0.5f)) & (ep2 < min_ep2);
min_ep2 = select(min_ep2, ep2, use_ep2);
vfloat4 err_max(ERROR_CALC_DEFAULT);
vmask4 err_mask = vint4::lane_id() == vint4(plane2_component);
// Set the plane2 component to max error in ep1
min_ep1 = select(min_ep1, err_max, err_mask);
float min_wt_cutoff1 = hmin_s(min_ep1);
// Set the minwt2 to the plane2 component min in ep2
float min_wt_cutoff2 = hmin_s(select(err_max, min_ep2, err_mask));
compute_angular_endpoints_2planes(
bsd, dec_weights_ideal, max_weight_quant, tmpbuf);
// For each mode (which specifies a decimation and a quantization):
// * Compute number of bits needed for the quantized weights
// * Generate an optimized set of quantized weights
// * Compute quantization errors for the mode
float* weight_low_value1 = tmpbuf.weight_low_value1;
float* weight_high_value1 = tmpbuf.weight_high_value1;
float* weight_low_value2 = tmpbuf.weight_low_value2;
float* weight_high_value2 = tmpbuf.weight_high_value2;
int8_t* qwt_bitcounts = tmpbuf.qwt_bitcounts;
float* qwt_errors = tmpbuf.qwt_errors;
unsigned int start_2plane = bsd.block_mode_count_1plane_selected;
unsigned int end_2plane = bsd.block_mode_count_1plane_2plane_selected;
for (unsigned int i = start_2plane; i < end_2plane; i++)
{
const block_mode& bm = bsd.block_modes[i];
assert(bm.is_dual_plane);
if (bm.quant_mode > max_weight_quant)
{
qwt_errors[i] = 1e38f;
continue;
}
qwt_bitcounts[i] = static_cast<int8_t>(109 - bm.weight_bits);
if (weight_high_value1[i] > 1.02f * min_wt_cutoff1)
{
weight_high_value1[i] = 1.0f;
}
if (weight_high_value2[i] > 1.02f * min_wt_cutoff2)
{
weight_high_value2[i] = 1.0f;
}
unsigned int decimation_mode = bm.decimation_mode;
const auto& di = bsd.get_decimation_info(decimation_mode);
ASTCENC_ALIGNAS float dec_weights_uquantf[BLOCK_MAX_WEIGHTS];
// Generate the optimized set of weights for the mode
compute_quantized_weights_for_decimation(
di,
weight_low_value1[i],
weight_high_value1[i],
dec_weights_ideal + BLOCK_MAX_WEIGHTS * decimation_mode,
dec_weights_uquantf,
dec_weights_uquant + BLOCK_MAX_WEIGHTS * i,
bm.get_weight_quant_mode());
compute_quantized_weights_for_decimation(
di,
weight_low_value2[i],
weight_high_value2[i],
dec_weights_ideal + BLOCK_MAX_WEIGHTS * decimation_mode + WEIGHTS_PLANE2_OFFSET,
dec_weights_uquantf + WEIGHTS_PLANE2_OFFSET,
dec_weights_uquant + BLOCK_MAX_WEIGHTS * i + WEIGHTS_PLANE2_OFFSET,
bm.get_weight_quant_mode());
// Compute weight quantization errors for the block mode
qwt_errors[i] = compute_error_of_weight_set_2planes(
ei1,
ei2,
di,
dec_weights_uquantf,
dec_weights_uquantf + WEIGHTS_PLANE2_OFFSET);
}
// Decide the optimal combination of color endpoint encodings and weight encodings
uint8_t partition_format_specifiers[TUNE_MAX_TRIAL_CANDIDATES][BLOCK_MAX_PARTITIONS];
int block_mode_index[TUNE_MAX_TRIAL_CANDIDATES];
quant_method color_quant_level[TUNE_MAX_TRIAL_CANDIDATES];
quant_method color_quant_level_mod[TUNE_MAX_TRIAL_CANDIDATES];
endpoints epm;
merge_endpoints(ei1.ep, ei2.ep, plane2_component, epm);
const auto& pi = bsd.get_partition_info(1, 0);
unsigned int candidate_count = compute_ideal_endpoint_formats(
pi, blk, epm, qwt_bitcounts, qwt_errors,
config.tune_candidate_limit,
bsd.block_mode_count_1plane_selected, bsd.block_mode_count_1plane_2plane_selected,
partition_format_specifiers, block_mode_index,
color_quant_level, color_quant_level_mod, tmpbuf);
// Iterate over the N believed-to-be-best modes to find out which one is actually best
float best_errorval_in_mode = ERROR_CALC_DEFAULT;
float best_errorval_in_scb = scb.errorval;
for (unsigned int i = 0; i < candidate_count; i++)
{
TRACE_NODE(node0, "candidate");
const int bm_packed_index = block_mode_index[i];
assert(bm_packed_index >= static_cast<int>(bsd.block_mode_count_1plane_selected) &&
bm_packed_index < static_cast<int>(bsd.block_mode_count_1plane_2plane_selected));
const block_mode& qw_bm = bsd.block_modes[bm_packed_index];
int decimation_mode = qw_bm.decimation_mode;
const auto& di = bsd.get_decimation_info(decimation_mode);
promise(di.weight_count > 0);
trace_add_data("weight_x", di.weight_x);
trace_add_data("weight_y", di.weight_y);
trace_add_data("weight_z", di.weight_z);
trace_add_data("weight_quant", qw_bm.quant_mode);
vfloat4 rgbs_color;
vfloat4 rgbo_color;
symbolic_compressed_block workscb;
endpoints workep = epm;
uint8_t* u8_weight1_src = dec_weights_uquant + BLOCK_MAX_WEIGHTS * bm_packed_index;
uint8_t* u8_weight2_src = dec_weights_uquant + BLOCK_MAX_WEIGHTS * bm_packed_index + WEIGHTS_PLANE2_OFFSET;
for (int j = 0; j < di.weight_count; j++)
{
workscb.weights[j] = u8_weight1_src[j];
workscb.weights[j + WEIGHTS_PLANE2_OFFSET] = u8_weight2_src[j];
}
for (unsigned int l = 0; l < config.tune_refinement_limit; l++)
{
recompute_ideal_colors_2planes(
blk, bsd, di,
workscb.weights, workscb.weights + WEIGHTS_PLANE2_OFFSET,
workep, rgbs_color, rgbo_color, plane2_component);
// Quantize the chosen color
workscb.color_formats[0] = pack_color_endpoints(
workep.endpt0[0],
workep.endpt1[0],
rgbs_color, rgbo_color,
partition_format_specifiers[i][0],
workscb.color_values[0],
color_quant_level[i]);
// Store header fields
workscb.partition_count = 1;
workscb.partition_index = 0;
workscb.quant_mode = color_quant_level[i];
workscb.color_formats_matched = 0;
workscb.block_mode = qw_bm.mode_index;
workscb.plane2_component = static_cast<int8_t>(plane2_component);
workscb.block_type = SYM_BTYPE_NONCONST;
// Pre-realign test
if (l == 0)
{
float errorval = compute_symbolic_block_difference_2plane(config, bsd, workscb, blk);
if (errorval == -ERROR_CALC_DEFAULT)
{
errorval = -errorval;
workscb.block_type = SYM_BTYPE_ERROR;
}
trace_add_data("error_prerealign", errorval);
best_errorval_in_mode = astc::min(errorval, best_errorval_in_mode);
// Average refinement improvement is 3.5% per iteration (allow 4.5%), but the first
// iteration can help more so we give it a extra 8% leeway. Use this knowledge to
// drive a heuristic to skip blocks that are unlikely to catch up with the best
// block we have already.
unsigned int iters_remaining = config.tune_refinement_limit - l;
float threshold = (0.045f * static_cast<float>(iters_remaining)) + 1.08f;
if (errorval > (threshold * best_errorval_in_scb))
{
break;
}
if (errorval < best_errorval_in_scb)
{
best_errorval_in_scb = errorval;
workscb.errorval = errorval;
scb = workscb;
if (errorval < tune_errorval_threshold)
{
// Skip remaining candidates - this is "good enough"
i = candidate_count;
break;
}
}
}
// Perform a final pass over the weights to try to improve them.
bool adjustments;
if (di.weight_count != bsd.texel_count)
{
adjustments = realign_weights_decimated(
config.profile, bsd, blk, workscb);
}
else
{
adjustments = realign_weights_undecimated(
config.profile, bsd, blk, workscb);
}
// Post-realign test
float errorval = compute_symbolic_block_difference_2plane(config, bsd, workscb, blk);
if (errorval == -ERROR_CALC_DEFAULT)
{
errorval = -errorval;
workscb.block_type = SYM_BTYPE_ERROR;
}
trace_add_data("error_postrealign", errorval);
best_errorval_in_mode = astc::min(errorval, best_errorval_in_mode);
// Average refinement improvement is 3.5% per iteration, so skip blocks that are
// unlikely to catch up with the best block we have already. Assume a 4.5% per step to
// give benefit of the doubt ...
unsigned int iters_remaining = config.tune_refinement_limit - 1 - l;
float threshold = (0.045f * static_cast<float>(iters_remaining)) + 1.0f;
if (errorval > (threshold * best_errorval_in_scb))
{
break;
}
if (errorval < best_errorval_in_scb)
{
best_errorval_in_scb = errorval;
workscb.errorval = errorval;
scb = workscb;
if (errorval < tune_errorval_threshold)
{
// Skip remaining candidates - this is "good enough"
i = candidate_count;
break;
}
}
if (!adjustments)
{
break;
}
}
}
return best_errorval_in_mode;
}
/**
* @brief Determine the lowest cross-channel correlation factor.
*
* @param texels_per_block The number of texels in a block.
* @param blk The image block color data to compress.
*
* @return Return the lowest correlation factor.
*/
static float prepare_block_statistics(
int texels_per_block,
const image_block& blk
) {
// Compute covariance matrix, as a collection of 10 scalars that form the upper-triangular row
// of the matrix. The matrix is symmetric, so this is all we need for this use case.
float rs = 0.0f;
float gs = 0.0f;
float bs = 0.0f;
float as = 0.0f;
float rr_var = 0.0f;
float gg_var = 0.0f;
float bb_var = 0.0f;
float aa_var = 0.0f;
float rg_cov = 0.0f;
float rb_cov = 0.0f;
float ra_cov = 0.0f;
float gb_cov = 0.0f;
float ga_cov = 0.0f;
float ba_cov = 0.0f;
float weight_sum = 0.0f;
promise(texels_per_block > 0);
for (int i = 0; i < texels_per_block; i++)
{
float weight = hadd_s(blk.channel_weight) / 4.0f;
assert(weight >= 0.0f);
weight_sum += weight;
float r = blk.data_r[i];
float g = blk.data_g[i];
float b = blk.data_b[i];
float a = blk.data_a[i];
float rw = r * weight;
rs += rw;
rr_var += r * rw;
rg_cov += g * rw;
rb_cov += b * rw;
ra_cov += a * rw;
float gw = g * weight;
gs += gw;
gg_var += g * gw;
gb_cov += b * gw;
ga_cov += a * gw;
float bw = b * weight;
bs += bw;
bb_var += b * bw;
ba_cov += a * bw;
float aw = a * weight;
as += aw;
aa_var += a * aw;
}
float rpt = 1.0f / astc::max(weight_sum, 1e-7f);
rr_var -= rs * (rs * rpt);
rg_cov -= gs * (rs * rpt);
rb_cov -= bs * (rs * rpt);
ra_cov -= as * (rs * rpt);
gg_var -= gs * (gs * rpt);
gb_cov -= bs * (gs * rpt);
ga_cov -= as * (gs * rpt);
bb_var -= bs * (bs * rpt);
ba_cov -= as * (bs * rpt);
aa_var -= as * (as * rpt);
// These will give a NaN if a channel is constant - these are fixed up in the next step
rg_cov *= astc::rsqrt(rr_var * gg_var);
rb_cov *= astc::rsqrt(rr_var * bb_var);
ra_cov *= astc::rsqrt(rr_var * aa_var);
gb_cov *= astc::rsqrt(gg_var * bb_var);
ga_cov *= astc::rsqrt(gg_var * aa_var);
ba_cov *= astc::rsqrt(bb_var * aa_var);
if (astc::isnan(rg_cov)) rg_cov = 1.0f;
if (astc::isnan(rb_cov)) rb_cov = 1.0f;
if (astc::isnan(ra_cov)) ra_cov = 1.0f;
if (astc::isnan(gb_cov)) gb_cov = 1.0f;
if (astc::isnan(ga_cov)) ga_cov = 1.0f;
if (astc::isnan(ba_cov)) ba_cov = 1.0f;
float lowest_correlation = astc::min(fabsf(rg_cov), fabsf(rb_cov));
lowest_correlation = astc::min(lowest_correlation, fabsf(ra_cov));
lowest_correlation = astc::min(lowest_correlation, fabsf(gb_cov));
lowest_correlation = astc::min(lowest_correlation, fabsf(ga_cov));
lowest_correlation = astc::min(lowest_correlation, fabsf(ba_cov));
// Diagnostic trace points
trace_add_data("min_r", blk.data_min.lane<0>());
trace_add_data("max_r", blk.data_max.lane<0>());
trace_add_data("min_g", blk.data_min.lane<1>());
trace_add_data("max_g", blk.data_max.lane<1>());
trace_add_data("min_b", blk.data_min.lane<2>());
trace_add_data("max_b", blk.data_max.lane<2>());
trace_add_data("min_a", blk.data_min.lane<3>());
trace_add_data("max_a", blk.data_max.lane<3>());
trace_add_data("cov_rg", fabsf(rg_cov));
trace_add_data("cov_rb", fabsf(rb_cov));
trace_add_data("cov_ra", fabsf(ra_cov));
trace_add_data("cov_gb", fabsf(gb_cov));
trace_add_data("cov_ga", fabsf(ga_cov));
trace_add_data("cov_ba", fabsf(ba_cov));
return lowest_correlation;
}
/* See header for documentation. */
void compress_block(
const astcenc_contexti& ctx,
const image_block& blk,
uint8_t pcb[16],
compression_working_buffers& tmpbuf)
{
astcenc_profile decode_mode = ctx.config.profile;
symbolic_compressed_block scb;
const block_size_descriptor& bsd = *ctx.bsd;
float lowest_correl;
TRACE_NODE(node0, "block");
trace_add_data("pos_x", blk.xpos);
trace_add_data("pos_y", blk.ypos);
trace_add_data("pos_z", blk.zpos);
// Set stricter block targets for luminance data as we have more bits to play with
bool block_is_l = blk.is_luminance();
float block_is_l_scale = block_is_l ? 1.0f / 1.5f : 1.0f;
// Set slightly stricter block targets for lumalpha data as we have more bits to play with
bool block_is_la = blk.is_luminancealpha();
float block_is_la_scale = block_is_la ? 1.0f / 1.05f : 1.0f;
bool block_skip_two_plane = false;
int max_partitions = ctx.config.tune_partition_count_limit;
unsigned int requested_partition_indices[3] {
ctx.config.tune_2partition_index_limit,
ctx.config.tune_3partition_index_limit,
ctx.config.tune_4partition_index_limit
};
unsigned int requested_partition_trials[3] {
ctx.config.tune_2partitioning_candidate_limit,
ctx.config.tune_3partitioning_candidate_limit,
ctx.config.tune_4partitioning_candidate_limit
};
#if defined(ASTCENC_DIAGNOSTICS)
// Do this early in diagnostic builds so we can dump uniform metrics
// for every block. Do it later in release builds to avoid redundant work!
float error_weight_sum = hadd_s(blk.channel_weight) * bsd.texel_count;
float error_threshold = ctx.config.tune_db_limit
* error_weight_sum
* block_is_l_scale
* block_is_la_scale;
lowest_correl = prepare_block_statistics(bsd.texel_count, blk);
trace_add_data("lowest_correl", lowest_correl);
trace_add_data("tune_error_threshold", error_threshold);
#endif
// Detected a constant-color block
if (all(blk.data_min == blk.data_max))
{
TRACE_NODE(node1, "pass");
trace_add_data("partition_count", 0);
trace_add_data("plane_count", 1);
scb.partition_count = 0;
// Encode as FP16 if using HDR
if ((decode_mode == ASTCENC_PRF_HDR) ||
(decode_mode == ASTCENC_PRF_HDR_RGB_LDR_A))
{
scb.block_type = SYM_BTYPE_CONST_F16;
vint4 color_f16 = float_to_float16(blk.origin_texel);
store(color_f16, scb.constant_color);
}
// Encode as UNORM16 if NOT using HDR
else
{
scb.block_type = SYM_BTYPE_CONST_U16;
vfloat4 color_f32 = clamp(0.0f, 1.0f, blk.origin_texel) * 65535.0f;
vint4 color_u16 = float_to_int_rtn(color_f32);
store(color_u16, scb.constant_color);
}
trace_add_data("exit", "quality hit");
symbolic_to_physical(bsd, scb, pcb);
return;
}
#if !defined(ASTCENC_DIAGNOSTICS)
float error_weight_sum = hadd_s(blk.channel_weight) * bsd.texel_count;
float error_threshold = ctx.config.tune_db_limit
* error_weight_sum
* block_is_l_scale
* block_is_la_scale;
#endif
// Set SCB and mode errors to a very high error value
scb.errorval = ERROR_CALC_DEFAULT;
scb.block_type = SYM_BTYPE_ERROR;
float best_errorvals_for_pcount[BLOCK_MAX_PARTITIONS] {
ERROR_CALC_DEFAULT, ERROR_CALC_DEFAULT, ERROR_CALC_DEFAULT, ERROR_CALC_DEFAULT
};
float exit_thresholds_for_pcount[BLOCK_MAX_PARTITIONS] {
0.0f,
ctx.config.tune_2partition_early_out_limit_factor,
ctx.config.tune_3partition_early_out_limit_factor,
0.0f
};
// Trial using 1 plane of weights and 1 partition.
// Most of the time we test it twice, first with a mode cutoff of 0 and then with the specified
// mode cutoff. This causes an early-out that speeds up encoding of easy blocks. However, this
// optimization is disabled for 4x4 and 5x4 blocks where it nearly always slows down the
// compression and slightly reduces image quality.
float errorval_mult[2] {
1.0f / ctx.config.tune_mse_overshoot,
1.0f
};
const float errorval_overshoot = 1.0f / ctx.config.tune_mse_overshoot;
// Only enable MODE0 fast path if enabled
// Never enable for 3D blocks as no "always" block modes are available
int start_trial = 1;
if ((ctx.config.tune_search_mode0_enable >= TUNE_MIN_SEARCH_MODE0) && (bsd.zdim == 1))
{
start_trial = 0;
}
int quant_limit = QUANT_32;
for (int i = start_trial; i < 2; i++)
{
TRACE_NODE(node1, "pass");
trace_add_data("partition_count", 1);
trace_add_data("plane_count", 1);
trace_add_data("search_mode", i);
float errorval = compress_symbolic_block_for_partition_1plane(
ctx.config, bsd, blk, i == 0,
error_threshold * errorval_mult[i] * errorval_overshoot,
1, 0, scb, tmpbuf, QUANT_32);
// Record the quant level so we can use the filter later searches
const auto& bm = bsd.get_block_mode(scb.block_mode);
quant_limit = bm.get_weight_quant_mode();
best_errorvals_for_pcount[0] = astc::min(best_errorvals_for_pcount[0], errorval);
if (errorval < (error_threshold * errorval_mult[i]))
{
trace_add_data("exit", "quality hit");
goto END_OF_TESTS;
}
}
#if !defined(ASTCENC_DIAGNOSTICS)
lowest_correl = prepare_block_statistics(bsd.texel_count, blk);
#endif
block_skip_two_plane = lowest_correl > ctx.config.tune_2plane_early_out_limit_correlation;
// Test the four possible 1-partition, 2-planes modes. Do this in reverse, as
// alpha is the most likely to be non-correlated if it is present in the data.
for (int i = BLOCK_MAX_COMPONENTS - 1; i >= 0; i--)
{
TRACE_NODE(node1, "pass");
trace_add_data("partition_count", 1);
trace_add_data("plane_count", 2);
trace_add_data("plane_component", i);
if (block_skip_two_plane)
{
trace_add_data("skip", "tune_2plane_early_out_limit_correlation");
continue;
}
if (blk.grayscale && i != 3)
{
trace_add_data("skip", "grayscale block");
continue;
}
if (blk.is_constant_channel(i))
{
trace_add_data("skip", "constant component");
continue;
}
float errorval = compress_symbolic_block_for_partition_2planes(
ctx.config, bsd, blk, error_threshold * errorval_overshoot,
i, scb, tmpbuf, quant_limit);
// If attempting two planes is much worse than the best one plane result
// then further two plane searches are unlikely to help so move on ...
if (errorval > (best_errorvals_for_pcount[0] * 1.85f))
{
break;
}
if (errorval < error_threshold)
{
trace_add_data("exit", "quality hit");
goto END_OF_TESTS;
}
}
// Find best blocks for 2, 3 and 4 partitions
for (int partition_count = 2; partition_count <= max_partitions; partition_count++)
{
unsigned int partition_indices[TUNE_MAX_PARTITIONING_CANDIDATES];
unsigned int requested_indices = requested_partition_indices[partition_count - 2];
unsigned int requested_trials = requested_partition_trials[partition_count - 2];
requested_trials = astc::min(requested_trials, requested_indices);
unsigned int actual_trials = find_best_partition_candidates(
bsd, blk, partition_count, requested_indices, partition_indices, requested_trials);
float best_error_in_prev = best_errorvals_for_pcount[partition_count - 2];
for (unsigned int i = 0; i < actual_trials; i++)
{
TRACE_NODE(node1, "pass");
trace_add_data("partition_count", partition_count);
trace_add_data("partition_index", partition_indices[i]);
trace_add_data("plane_count", 1);
trace_add_data("search_mode", i);
float errorval = compress_symbolic_block_for_partition_1plane(
ctx.config, bsd, blk, false,
error_threshold * errorval_overshoot,
partition_count, partition_indices[i],
scb, tmpbuf, quant_limit);
best_errorvals_for_pcount[partition_count - 1] = astc::min(best_errorvals_for_pcount[partition_count - 1], errorval);
// If using N partitions doesn't improve much over using N-1 partitions then skip trying
// N+1. Error can dramatically improve if the data is correlated or non-correlated and
// aligns with a partitioning that suits that encoding, so for this inner loop check add
// a large error scale because the "other" trial could be a lot better.
float best_error = best_errorvals_for_pcount[partition_count - 1];
float best_error_scale = exit_thresholds_for_pcount[partition_count - 1] * 1.85f;
if (best_error > (best_error_in_prev * best_error_scale))
{
trace_add_data("skip", "tune_partition_early_out_limit_factor");
goto END_OF_TESTS;
}
if (errorval < error_threshold)
{
trace_add_data("exit", "quality hit");
goto END_OF_TESTS;
}
}
// If using N partitions doesn't improve much over using N-1 partitions then skip trying N+1
float best_error = best_errorvals_for_pcount[partition_count - 1];
float best_error_scale = exit_thresholds_for_pcount[partition_count - 1];
if (best_error > (best_error_in_prev * best_error_scale))
{
trace_add_data("skip", "tune_partition_early_out_limit_factor");
goto END_OF_TESTS;
}
}
trace_add_data("exit", "quality not hit");
END_OF_TESTS:
// If we still have an error block then convert to something we can encode
// TODO: Do something more sensible here, such as average color block
if (scb.block_type == SYM_BTYPE_ERROR)
{
#if defined(ASTCENC_DIAGNOSTICS)
static bool printed_once = false;
if (!printed_once)
{
printed_once = true;
printf("WARN: At least one block failed to find a valid encoding.\n"
" Try increasing compression quality settings.\n\n");
}
#endif
scb.block_type = SYM_BTYPE_CONST_U16;
vfloat4 color_f32 = clamp(0.0f, 1.0f, blk.origin_texel) * 65535.0f;
vint4 color_u16 = float_to_int_rtn(color_f32);
store(color_u16, scb.constant_color);
}
// Compress to a physical block
symbolic_to_physical(bsd, scb, pcb);
}
#endif
|