// Copyright 2012 Google Inc. All Rights Reserved. // // Use of this source code is governed by a BSD-style license // that can be found in the COPYING file in the root of the source // tree. An additional intellectual property rights grant can be found // in the file PATENTS. All contributing project authors may // be found in the AUTHORS file in the root of the source tree. // ----------------------------------------------------------------------------- // // Image transforms and color space conversion methods for lossless decoder. // // Authors: Vikas Arora (vikaas.arora@gmail.com) // Jyrki Alakuijala (jyrki@google.com) // Urvang Joshi (urvang@google.com) #include "./dsp.h" #include #include #include "../dec/vp8li.h" #include "../utils/endian_inl.h" #include "./lossless.h" #include "./yuv.h" #define MAX_DIFF_COST (1e30f) // lookup table for small values of log2(int) const float kLog2Table[LOG_LOOKUP_IDX_MAX] = { 0.0000000000000000f, 0.0000000000000000f, 1.0000000000000000f, 1.5849625007211560f, 2.0000000000000000f, 2.3219280948873621f, 2.5849625007211560f, 2.8073549220576041f, 3.0000000000000000f, 3.1699250014423121f, 3.3219280948873621f, 3.4594316186372973f, 3.5849625007211560f, 3.7004397181410921f, 3.8073549220576041f, 3.9068905956085187f, 4.0000000000000000f, 4.0874628412503390f, 4.1699250014423121f, 4.2479275134435852f, 4.3219280948873626f, 4.3923174227787606f, 4.4594316186372973f, 4.5235619560570130f, 4.5849625007211560f, 4.6438561897747243f, 4.7004397181410917f, 4.7548875021634682f, 4.8073549220576037f, 4.8579809951275718f, 4.9068905956085187f, 4.9541963103868749f, 5.0000000000000000f, 5.0443941193584533f, 5.0874628412503390f, 5.1292830169449663f, 5.1699250014423121f, 5.2094533656289501f, 5.2479275134435852f, 5.2854022188622487f, 5.3219280948873626f, 5.3575520046180837f, 5.3923174227787606f, 5.4262647547020979f, 5.4594316186372973f, 5.4918530963296747f, 5.5235619560570130f, 5.5545888516776376f, 5.5849625007211560f, 5.6147098441152083f, 5.6438561897747243f, 5.6724253419714951f, 5.7004397181410917f, 5.7279204545631987f, 5.7548875021634682f, 5.7813597135246599f, 5.8073549220576037f, 5.8328900141647412f, 5.8579809951275718f, 5.8826430493618415f, 5.9068905956085187f, 5.9307373375628866f, 5.9541963103868749f, 5.9772799234999167f, 6.0000000000000000f, 6.0223678130284543f, 6.0443941193584533f, 6.0660891904577720f, 6.0874628412503390f, 6.1085244567781691f, 6.1292830169449663f, 6.1497471195046822f, 6.1699250014423121f, 6.1898245588800175f, 6.2094533656289501f, 6.2288186904958804f, 6.2479275134435852f, 6.2667865406949010f, 6.2854022188622487f, 6.3037807481771030f, 6.3219280948873626f, 6.3398500028846243f, 6.3575520046180837f, 6.3750394313469245f, 6.3923174227787606f, 6.4093909361377017f, 6.4262647547020979f, 6.4429434958487279f, 6.4594316186372973f, 6.4757334309663976f, 6.4918530963296747f, 6.5077946401986963f, 6.5235619560570130f, 6.5391588111080309f, 6.5545888516776376f, 6.5698556083309478f, 6.5849625007211560f, 6.5999128421871278f, 6.6147098441152083f, 6.6293566200796094f, 6.6438561897747243f, 6.6582114827517946f, 6.6724253419714951f, 6.6865005271832185f, 6.7004397181410917f, 6.7142455176661224f, 6.7279204545631987f, 6.7414669864011464f, 6.7548875021634682f, 6.7681843247769259f, 6.7813597135246599f, 6.7944158663501061f, 6.8073549220576037f, 6.8201789624151878f, 6.8328900141647412f, 6.8454900509443747f, 6.8579809951275718f, 6.8703647195834047f, 6.8826430493618415f, 6.8948177633079437f, 6.9068905956085187f, 6.9188632372745946f, 6.9307373375628866f, 6.9425145053392398f, 6.9541963103868749f, 6.9657842846620869f, 6.9772799234999167f, 6.9886846867721654f, 7.0000000000000000f, 7.0112272554232539f, 7.0223678130284543f, 7.0334230015374501f, 7.0443941193584533f, 7.0552824355011898f, 7.0660891904577720f, 7.0768155970508308f, 7.0874628412503390f, 7.0980320829605263f, 7.1085244567781691f, 7.1189410727235076f, 7.1292830169449663f, 7.1395513523987936f, 7.1497471195046822f, 7.1598713367783890f, 7.1699250014423121f, 7.1799090900149344f, 7.1898245588800175f, 7.1996723448363644f, 7.2094533656289501f, 7.2191685204621611f, 7.2288186904958804f, 7.2384047393250785f, 7.2479275134435852f, 7.2573878426926521f, 7.2667865406949010f, 7.2761244052742375f, 7.2854022188622487f, 7.2946207488916270f, 7.3037807481771030f, 7.3128829552843557f, 7.3219280948873626f, 7.3309168781146167f, 7.3398500028846243f, 7.3487281542310771f, 7.3575520046180837f, 7.3663222142458160f, 7.3750394313469245f, 7.3837042924740519f, 7.3923174227787606f, 7.4008794362821843f, 7.4093909361377017f, 7.4178525148858982f, 7.4262647547020979f, 7.4346282276367245f, 7.4429434958487279f, 7.4512111118323289f, 7.4594316186372973f, 7.4676055500829976f, 7.4757334309663976f, 7.4838157772642563f, 7.4918530963296747f, 7.4998458870832056f, 7.5077946401986963f, 7.5156998382840427f, 7.5235619560570130f, 7.5313814605163118f, 7.5391588111080309f, 7.5468944598876364f, 7.5545888516776376f, 7.5622424242210728f, 7.5698556083309478f, 7.5774288280357486f, 7.5849625007211560f, 7.5924570372680806f, 7.5999128421871278f, 7.6073303137496104f, 7.6147098441152083f, 7.6220518194563764f, 7.6293566200796094f, 7.6366246205436487f, 7.6438561897747243f, 7.6510516911789281f, 7.6582114827517946f, 7.6653359171851764f, 7.6724253419714951f, 7.6794800995054464f, 7.6865005271832185f, 7.6934869574993252f, 7.7004397181410917f, 7.7073591320808825f, 7.7142455176661224f, 7.7210991887071855f, 7.7279204545631987f, 7.7347096202258383f, 7.7414669864011464f, 7.7481928495894605f, 7.7548875021634682f, 7.7615512324444795f, 7.7681843247769259f, 7.7747870596011736f, 7.7813597135246599f, 7.7879025593914317f, 7.7944158663501061f, 7.8008998999203047f, 7.8073549220576037f, 7.8137811912170374f, 7.8201789624151878f, 7.8265484872909150f, 7.8328900141647412f, 7.8392037880969436f, 7.8454900509443747f, 7.8517490414160571f, 7.8579809951275718f, 7.8641861446542797f, 7.8703647195834047f, 7.8765169465649993f, 7.8826430493618415f, 7.8887432488982591f, 7.8948177633079437f, 7.9008668079807486f, 7.9068905956085187f, 7.9128893362299619f, 7.9188632372745946f, 7.9248125036057812f, 7.9307373375628866f, 7.9366379390025709f, 7.9425145053392398f, 7.9483672315846778f, 7.9541963103868749f, 7.9600019320680805f, 7.9657842846620869f, 7.9715435539507719f, 7.9772799234999167f, 7.9829935746943103f, 7.9886846867721654f, 7.9943534368588577f }; const float kSLog2Table[LOG_LOOKUP_IDX_MAX] = { 0.00000000f, 0.00000000f, 2.00000000f, 4.75488750f, 8.00000000f, 11.60964047f, 15.50977500f, 19.65148445f, 24.00000000f, 28.52932501f, 33.21928095f, 38.05374781f, 43.01955001f, 48.10571634f, 53.30296891f, 58.60335893f, 64.00000000f, 69.48686830f, 75.05865003f, 80.71062276f, 86.43856190f, 92.23866588f, 98.10749561f, 104.04192499f, 110.03910002f, 116.09640474f, 122.21143267f, 128.38196256f, 134.60593782f, 140.88144886f, 147.20671787f, 153.58008562f, 160.00000000f, 166.46500594f, 172.97373660f, 179.52490559f, 186.11730005f, 192.74977453f, 199.42124551f, 206.13068654f, 212.87712380f, 219.65963219f, 226.47733176f, 233.32938445f, 240.21499122f, 247.13338933f, 254.08384998f, 261.06567603f, 268.07820003f, 275.12078236f, 282.19280949f, 289.29369244f, 296.42286534f, 303.57978409f, 310.76392512f, 317.97478424f, 325.21187564f, 332.47473081f, 339.76289772f, 347.07593991f, 354.41343574f, 361.77497759f, 369.16017124f, 376.56863518f, 384.00000000f, 391.45390785f, 398.93001188f, 406.42797576f, 413.94747321f, 421.48818752f, 429.04981119f, 436.63204548f, 444.23460010f, 451.85719280f, 459.49954906f, 467.16140179f, 474.84249102f, 482.54256363f, 490.26137307f, 497.99867911f, 505.75424759f, 513.52785023f, 521.31926438f, 529.12827280f, 536.95466351f, 544.79822957f, 552.65876890f, 560.53608414f, 568.42998244f, 576.34027536f, 584.26677867f, 592.20931226f, 600.16769996f, 608.14176943f, 616.13135206f, 624.13628279f, 632.15640007f, 640.19154569f, 648.24156472f, 656.30630539f, 664.38561898f, 672.47935976f, 680.58738488f, 688.70955430f, 696.84573069f, 704.99577935f, 713.15956818f, 721.33696754f, 729.52785023f, 737.73209140f, 745.94956849f, 754.18016116f, 762.42375127f, 770.68022275f, 778.94946161f, 787.23135586f, 795.52579543f, 803.83267219f, 812.15187982f, 820.48331383f, 828.82687147f, 837.18245171f, 845.54995518f, 853.92928416f, 862.32034249f, 870.72303558f, 879.13727036f, 887.56295522f, 896.00000000f, 904.44831595f, 912.90781569f, 921.37841320f, 929.86002376f, 938.35256392f, 946.85595152f, 955.37010560f, 963.89494641f, 972.43039537f, 980.97637504f, 989.53280911f, 998.09962237f, 1006.67674069f, 1015.26409097f, 1023.86160116f, 1032.46920021f, 1041.08681805f, 1049.71438560f, 1058.35183469f, 1066.99909811f, 1075.65610955f, 1084.32280357f, 1092.99911564f, 1101.68498204f, 1110.38033993f, 1119.08512727f, 1127.79928282f, 1136.52274614f, 1145.25545758f, 1153.99735821f, 1162.74838989f, 1171.50849518f, 1180.27761738f, 1189.05570047f, 1197.84268914f, 1206.63852876f, 1215.44316535f, 1224.25654560f, 1233.07861684f, 1241.90932703f, 1250.74862473f, 1259.59645914f, 1268.45278005f, 1277.31753781f, 1286.19068338f, 1295.07216828f, 1303.96194457f, 1312.85996488f, 1321.76618236f, 1330.68055071f, 1339.60302413f, 1348.53355734f, 1357.47210556f, 1366.41862452f, 1375.37307041f, 1384.33539991f, 1393.30557020f, 1402.28353887f, 1411.26926400f, 1420.26270412f, 1429.26381818f, 1438.27256558f, 1447.28890615f, 1456.31280014f, 1465.34420819f, 1474.38309138f, 1483.42941118f, 1492.48312945f, 1501.54420843f, 1510.61261078f, 1519.68829949f, 1528.77123795f, 1537.86138993f, 1546.95871952f, 1556.06319119f, 1565.17476976f, 1574.29342040f, 1583.41910860f, 1592.55180020f, 1601.69146137f, 1610.83805860f, 1619.99155871f, 1629.15192882f, 1638.31913637f, 1647.49314911f, 1656.67393509f, 1665.86146266f, 1675.05570047f, 1684.25661744f, 1693.46418280f, 1702.67836605f, 1711.89913698f, 1721.12646563f, 1730.36032233f, 1739.60067768f, 1748.84750254f, 1758.10076802f, 1767.36044551f, 1776.62650662f, 1785.89892323f, 1795.17766747f, 1804.46271172f, 1813.75402857f, 1823.05159087f, 1832.35537170f, 1841.66534438f, 1850.98148244f, 1860.30375965f, 1869.63214999f, 1878.96662767f, 1888.30716711f, 1897.65374295f, 1907.00633003f, 1916.36490342f, 1925.72943838f, 1935.09991037f, 1944.47629506f, 1953.85856831f, 1963.24670620f, 1972.64068498f, 1982.04048108f, 1991.44607117f, 2000.85743204f, 2010.27454072f, 2019.69737440f, 2029.12591044f, 2038.56012640f }; const VP8LPrefixCode kPrefixEncodeCode[PREFIX_LOOKUP_IDX_MAX] = { { 0, 0}, { 0, 0}, { 1, 0}, { 2, 0}, { 3, 0}, { 4, 1}, { 4, 1}, { 5, 1}, { 5, 1}, { 6, 2}, { 6, 2}, { 6, 2}, { 6, 2}, { 7, 2}, { 7, 2}, { 7, 2}, { 7, 2}, { 8, 3}, { 8, 3}, { 8, 3}, { 8, 3}, { 8, 3}, { 8, 3}, { 8, 3}, { 8, 3}, { 9, 3}, { 9, 3}, { 9, 3}, { 9, 3}, { 9, 3}, { 9, 3}, { 9, 3}, { 9, 3}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {10, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {11, 4}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {12, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {13, 5}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {14, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {15, 6}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {16, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, {17, 7}, }; const uint8_t kPrefixEncodeExtraBitsValue[PREFIX_LOOKUP_IDX_MAX] = { 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 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, 0, 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, 0, 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, 0, 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, 0, 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, 0, 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 }; // The threshold till approximate version of log_2 can be used. // Practically, we can get rid of the call to log() as the two values match to // very high degree (the ratio of these two is 0.99999x). // Keeping a high threshold for now. #define APPROX_LOG_WITH_CORRECTION_MAX 65536 #define APPROX_LOG_MAX 4096 #define LOG_2_RECIPROCAL 1.44269504088896338700465094007086 static float FastSLog2Slow(uint32_t v) { assert(v >= LOG_LOOKUP_IDX_MAX); if (v < APPROX_LOG_WITH_CORRECTION_MAX) { int log_cnt = 0; uint32_t y = 1; int correction = 0; const float v_f = (float)v; const uint32_t orig_v = v; do { ++log_cnt; v = v >> 1; y = y << 1; } while (v >= LOG_LOOKUP_IDX_MAX); // vf = (2^log_cnt) * Xf; where y = 2^log_cnt and Xf < 256 // Xf = floor(Xf) * (1 + (v % y) / v) // log2(Xf) = log2(floor(Xf)) + log2(1 + (v % y) / v) // The correction factor: log(1 + d) ~ d; for very small d values, so // log2(1 + (v % y) / v) ~ LOG_2_RECIPROCAL * (v % y)/v // LOG_2_RECIPROCAL ~ 23/16 correction = (23 * (orig_v & (y - 1))) >> 4; return v_f * (kLog2Table[v] + log_cnt) + correction; } else { return (float)(LOG_2_RECIPROCAL * v * log((double)v)); } } static float FastLog2Slow(uint32_t v) { assert(v >= LOG_LOOKUP_IDX_MAX); if (v < APPROX_LOG_WITH_CORRECTION_MAX) { int log_cnt = 0; uint32_t y = 1; const uint32_t orig_v = v; double log_2; do { ++log_cnt; v = v >> 1; y = y << 1; } while (v >= LOG_LOOKUP_IDX_MAX); log_2 = kLog2Table[v] + log_cnt; if (orig_v >= APPROX_LOG_MAX) { // Since the division is still expensive, add this correction factor only // for large values of 'v'. const int correction = (23 * (orig_v & (y - 1))) >> 4; log_2 += (double)correction / orig_v; } return (float)log_2; } else { return (float)(LOG_2_RECIPROCAL * log((double)v)); } } //------------------------------------------------------------------------------ // Image transforms. // Mostly used to reduce code size + readability static WEBP_INLINE int GetMin(int a, int b) { return (a > b) ? b : a; } // In-place sum of each component with mod 256. static WEBP_INLINE void AddPixelsEq(uint32_t* a, uint32_t b) { const uint32_t alpha_and_green = (*a & 0xff00ff00u) + (b & 0xff00ff00u); const uint32_t red_and_blue = (*a & 0x00ff00ffu) + (b & 0x00ff00ffu); *a = (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu); } static WEBP_INLINE uint32_t Average2(uint32_t a0, uint32_t a1) { return (((a0 ^ a1) & 0xfefefefeL) >> 1) + (a0 & a1); } static WEBP_INLINE uint32_t Average3(uint32_t a0, uint32_t a1, uint32_t a2) { return Average2(Average2(a0, a2), a1); } static WEBP_INLINE uint32_t Average4(uint32_t a0, uint32_t a1, uint32_t a2, uint32_t a3) { return Average2(Average2(a0, a1), Average2(a2, a3)); } static WEBP_INLINE uint32_t Clip255(uint32_t a) { if (a < 256) { return a; } // return 0, when a is a negative integer. // return 255, when a is positive. return ~a >> 24; } static WEBP_INLINE int AddSubtractComponentFull(int a, int b, int c) { return Clip255(a + b - c); } static WEBP_INLINE uint32_t ClampedAddSubtractFull(uint32_t c0, uint32_t c1, uint32_t c2) { const int a = AddSubtractComponentFull(c0 >> 24, c1 >> 24, c2 >> 24); const int r = AddSubtractComponentFull((c0 >> 16) & 0xff, (c1 >> 16) & 0xff, (c2 >> 16) & 0xff); const int g = AddSubtractComponentFull((c0 >> 8) & 0xff, (c1 >> 8) & 0xff, (c2 >> 8) & 0xff); const int b = AddSubtractComponentFull(c0 & 0xff, c1 & 0xff, c2 & 0xff); return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b; } static WEBP_INLINE int AddSubtractComponentHalf(int a, int b) { return Clip255(a + (a - b) / 2); } static WEBP_INLINE uint32_t ClampedAddSubtractHalf(uint32_t c0, uint32_t c1, uint32_t c2) { const uint32_t ave = Average2(c0, c1); const int a = AddSubtractComponentHalf(ave >> 24, c2 >> 24); const int r = AddSubtractComponentHalf((ave >> 16) & 0xff, (c2 >> 16) & 0xff); const int g = AddSubtractComponentHalf((ave >> 8) & 0xff, (c2 >> 8) & 0xff); const int b = AddSubtractComponentHalf((ave >> 0) & 0xff, (c2 >> 0) & 0xff); return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b; } // gcc-4.9 on ARM generates incorrect code in Select() when Sub3() is inlined. #if defined(__arm__) && LOCAL_GCC_VERSION == 0x409 # define LOCAL_INLINE __attribute__ ((noinline)) #else # define LOCAL_INLINE WEBP_INLINE #endif static LOCAL_INLINE int Sub3(int a, int b, int c) { const int pb = b - c; const int pa = a - c; return abs(pb) - abs(pa); } #undef LOCAL_INLINE static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) { const int pa_minus_pb = Sub3((a >> 24) , (b >> 24) , (c >> 24) ) + Sub3((a >> 16) & 0xff, (b >> 16) & 0xff, (c >> 16) & 0xff) + Sub3((a >> 8) & 0xff, (b >> 8) & 0xff, (c >> 8) & 0xff) + Sub3((a ) & 0xff, (b ) & 0xff, (c ) & 0xff); return (pa_minus_pb <= 0) ? a : b; } //------------------------------------------------------------------------------ // Predictors static uint32_t Predictor0(uint32_t left, const uint32_t* const top) { (void)top; (void)left; return ARGB_BLACK; } static uint32_t Predictor1(uint32_t left, const uint32_t* const top) { (void)top; return left; } static uint32_t Predictor2(uint32_t left, const uint32_t* const top) { (void)left; return top[0]; } static uint32_t Predictor3(uint32_t left, const uint32_t* const top) { (void)left; return top[1]; } static uint32_t Predictor4(uint32_t left, const uint32_t* const top) { (void)left; return top[-1]; } static uint32_t Predictor5(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average3(left, top[0], top[1]); return pred; } static uint32_t Predictor6(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(left, top[-1]); return pred; } static uint32_t Predictor7(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(left, top[0]); return pred; } static uint32_t Predictor8(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(top[-1], top[0]); (void)left; return pred; } static uint32_t Predictor9(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(top[0], top[1]); (void)left; return pred; } static uint32_t Predictor10(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average4(left, top[-1], top[0], top[1]); return pred; } static uint32_t Predictor11(uint32_t left, const uint32_t* const top) { const uint32_t pred = Select(top[0], left, top[-1]); return pred; } static uint32_t Predictor12(uint32_t left, const uint32_t* const top) { const uint32_t pred = ClampedAddSubtractFull(left, top[0], top[-1]); return pred; } static uint32_t Predictor13(uint32_t left, const uint32_t* const top) { const uint32_t pred = ClampedAddSubtractHalf(left, top[0], top[-1]); return pred; } static const VP8LPredictorFunc kPredictorsC[16] = { Predictor0, Predictor1, Predictor2, Predictor3, Predictor4, Predictor5, Predictor6, Predictor7, Predictor8, Predictor9, Predictor10, Predictor11, Predictor12, Predictor13, Predictor0, Predictor0 // <- padding security sentinels }; static float PredictionCostSpatial(const int counts[256], int weight_0, double exp_val) { const int significant_symbols = 256 >> 4; const double exp_decay_factor = 0.6; double bits = weight_0 * counts[0]; int i; for (i = 1; i < significant_symbols; ++i) { bits += exp_val * (counts[i] + counts[256 - i]); exp_val *= exp_decay_factor; } return (float)(-0.1 * bits); } // Compute the combined Shanon's entropy for distribution {X} and {X+Y} static float CombinedShannonEntropy(const int X[256], const int Y[256]) { int i; double retval = 0.; int sumX = 0, sumXY = 0; for (i = 0; i < 256; ++i) { const int x = X[i]; const int xy = x + Y[i]; if (x != 0) { sumX += x; retval -= VP8LFastSLog2(x); sumXY += xy; retval -= VP8LFastSLog2(xy); } else if (xy != 0) { sumXY += xy; retval -= VP8LFastSLog2(xy); } } retval += VP8LFastSLog2(sumX) + VP8LFastSLog2(sumXY); return (float)retval; } static float PredictionCostSpatialHistogram(const int accumulated[4][256], const int tile[4][256]) { int i; double retval = 0; for (i = 0; i < 4; ++i) { const double kExpValue = 0.94; retval += PredictionCostSpatial(tile[i], 1, kExpValue); retval += CombinedShannonEntropy(tile[i], accumulated[i]); } return (float)retval; } static WEBP_INLINE void UpdateHisto(int histo_argb[4][256], uint32_t argb) { ++histo_argb[0][argb >> 24]; ++histo_argb[1][(argb >> 16) & 0xff]; ++histo_argb[2][(argb >> 8) & 0xff]; ++histo_argb[3][argb & 0xff]; } static int GetBestPredictorForTile(int width, int height, int tile_x, int tile_y, int bits, const int accumulated[4][256], const uint32_t* const argb_scratch) { const int kNumPredModes = 14; const int col_start = tile_x << bits; const int row_start = tile_y << bits; const int tile_size = 1 << bits; const int max_y = GetMin(tile_size, height - row_start); const int max_x = GetMin(tile_size, width - col_start); float best_diff = MAX_DIFF_COST; int best_mode = 0; int mode; for (mode = 0; mode < kNumPredModes; ++mode) { const uint32_t* current_row = argb_scratch; const VP8LPredictorFunc pred_func = VP8LPredictors[mode]; float cur_diff; int y; int histo_argb[4][256]; memset(histo_argb, 0, sizeof(histo_argb)); for (y = 0; y < max_y; ++y) { int x; const int row = row_start + y; const uint32_t* const upper_row = current_row; current_row = upper_row + width; for (x = 0; x < max_x; ++x) { const int col = col_start + x; uint32_t predict; if (row == 0) { predict = (col == 0) ? ARGB_BLACK : current_row[col - 1]; // Left. } else if (col == 0) { predict = upper_row[col]; // Top. } else { predict = pred_func(current_row[col - 1], upper_row + col); } UpdateHisto(histo_argb, VP8LSubPixels(current_row[col], predict)); } } cur_diff = PredictionCostSpatialHistogram( accumulated, (const int (*)[256])histo_argb); if (cur_diff < best_diff) { best_diff = cur_diff; best_mode = mode; } } return best_mode; } static void CopyTileWithPrediction(int width, int height, int tile_x, int tile_y, int bits, int mode, const uint32_t* const argb_scratch, uint32_t* const argb) { const int col_start = tile_x << bits; const int row_start = tile_y << bits; const int tile_size = 1 << bits; const int max_y = GetMin(tile_size, height - row_start); const int max_x = GetMin(tile_size, width - col_start); const VP8LPredictorFunc pred_func = VP8LPredictors[mode]; const uint32_t* current_row = argb_scratch; int y; for (y = 0; y < max_y; ++y) { int x; const int row = row_start + y; const uint32_t* const upper_row = current_row; current_row = upper_row + width; for (x = 0; x < max_x; ++x) { const int col = col_start + x; const int pix = row * width + col; uint32_t predict; if (row == 0) { predict = (col == 0) ? ARGB_BLACK : current_row[col - 1]; // Left. } else if (col == 0) { predict = upper_row[col]; // Top. } else { predict = pred_func(current_row[col - 1], upper_row + col); } argb[pix] = VP8LSubPixels(current_row[col], predict); } } } void VP8LResidualImage(int width, int height, int bits, uint32_t* const argb, uint32_t* const argb_scratch, uint32_t* const image) { const int max_tile_size = 1 << bits; const int tiles_per_row = VP8LSubSampleSize(width, bits); const int tiles_per_col = VP8LSubSampleSize(height, bits); uint32_t* const upper_row = argb_scratch; uint32_t* const current_tile_rows = argb_scratch + width; int tile_y; int histo[4][256]; memset(histo, 0, sizeof(histo)); for (tile_y = 0; tile_y < tiles_per_col; ++tile_y) { const int tile_y_offset = tile_y * max_tile_size; const int this_tile_height = (tile_y < tiles_per_col - 1) ? max_tile_size : height - tile_y_offset; int tile_x; if (tile_y > 0) { memcpy(upper_row, current_tile_rows + (max_tile_size - 1) * width, width * sizeof(*upper_row)); } memcpy(current_tile_rows, &argb[tile_y_offset * width], this_tile_height * width * sizeof(*current_tile_rows)); for (tile_x = 0; tile_x < tiles_per_row; ++tile_x) { int pred; int y; const int tile_x_offset = tile_x * max_tile_size; int all_x_max = tile_x_offset + max_tile_size; if (all_x_max > width) { all_x_max = width; } pred = GetBestPredictorForTile(width, height, tile_x, tile_y, bits, (const int (*)[256])histo, argb_scratch); image[tile_y * tiles_per_row + tile_x] = 0xff000000u | (pred << 8); CopyTileWithPrediction(width, height, tile_x, tile_y, bits, pred, argb_scratch, argb); for (y = 0; y < max_tile_size; ++y) { int ix; int all_x; int all_y = tile_y_offset + y; if (all_y >= height) { break; } ix = all_y * width + tile_x_offset; for (all_x = tile_x_offset; all_x < all_x_max; ++all_x, ++ix) { UpdateHisto(histo, argb[ix]); } } } } } // Inverse prediction. static void PredictorInverseTransform(const VP8LTransform* const transform, int y_start, int y_end, uint32_t* data) { const int width = transform->xsize_; if (y_start == 0) { // First Row follows the L (mode=1) mode. int x; const uint32_t pred0 = Predictor0(data[-1], NULL); AddPixelsEq(data, pred0); for (x = 1; x < width; ++x) { const uint32_t pred1 = Predictor1(data[x - 1], NULL); AddPixelsEq(data + x, pred1); } data += width; ++y_start; } { int y = y_start; const int tile_width = 1 << transform->bits_; const int mask = tile_width - 1; const int safe_width = width & ~mask; const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_); const uint32_t* pred_mode_base = transform->data_ + (y >> transform->bits_) * tiles_per_row; while (y < y_end) { const uint32_t pred2 = Predictor2(data[-1], data - width); const uint32_t* pred_mode_src = pred_mode_base; VP8LPredictorFunc pred_func; int x = 1; int t = 1; // First pixel follows the T (mode=2) mode. AddPixelsEq(data, pred2); // .. the rest: while (x < safe_width) { pred_func = VP8LPredictors[((*pred_mode_src++) >> 8) & 0xf]; for (; t < tile_width; ++t, ++x) { const uint32_t pred = pred_func(data[x - 1], data + x - width); AddPixelsEq(data + x, pred); } t = 0; } if (x < width) { pred_func = VP8LPredictors[((*pred_mode_src++) >> 8) & 0xf]; for (; x < width; ++x) { const uint32_t pred = pred_func(data[x - 1], data + x - width); AddPixelsEq(data + x, pred); } } data += width; ++y; if ((y & mask) == 0) { // Use the same mask, since tiles are squares. pred_mode_base += tiles_per_row; } } } } void VP8LSubtractGreenFromBlueAndRed_C(uint32_t* argb_data, int num_pixels) { int i; for (i = 0; i < num_pixels; ++i) { const uint32_t argb = argb_data[i]; const uint32_t green = (argb >> 8) & 0xff; const uint32_t new_r = (((argb >> 16) & 0xff) - green) & 0xff; const uint32_t new_b = ((argb & 0xff) - green) & 0xff; argb_data[i] = (argb & 0xff00ff00) | (new_r << 16) | new_b; } } // Add green to blue and red channels (i.e. perform the inverse transform of // 'subtract green'). void VP8LAddGreenToBlueAndRed_C(uint32_t* data, int num_pixels) { int i; for (i = 0; i < num_pixels; ++i) { const uint32_t argb = data[i]; const uint32_t green = ((argb >> 8) & 0xff); uint32_t red_blue = (argb & 0x00ff00ffu); red_blue += (green << 16) | green; red_blue &= 0x00ff00ffu; data[i] = (argb & 0xff00ff00u) | red_blue; } } static WEBP_INLINE void MultipliersClear(VP8LMultipliers* const m) { m->green_to_red_ = 0; m->green_to_blue_ = 0; m->red_to_blue_ = 0; } static WEBP_INLINE uint32_t ColorTransformDelta(int8_t color_pred, int8_t color) { return (uint32_t)((int)(color_pred) * color) >> 5; } static WEBP_INLINE void ColorCodeToMultipliers(uint32_t color_code, VP8LMultipliers* const m) { m->green_to_red_ = (color_code >> 0) & 0xff; m->green_to_blue_ = (color_code >> 8) & 0xff; m->red_to_blue_ = (color_code >> 16) & 0xff; } static WEBP_INLINE uint32_t MultipliersToColorCode( const VP8LMultipliers* const m) { return 0xff000000u | ((uint32_t)(m->red_to_blue_) << 16) | ((uint32_t)(m->green_to_blue_) << 8) | m->green_to_red_; } void VP8LTransformColor_C(const VP8LMultipliers* const m, uint32_t* data, int num_pixels) { int i; for (i = 0; i < num_pixels; ++i) { const uint32_t argb = data[i]; const uint32_t green = argb >> 8; const uint32_t red = argb >> 16; uint32_t new_red = red; uint32_t new_blue = argb; new_red -= ColorTransformDelta(m->green_to_red_, green); new_red &= 0xff; new_blue -= ColorTransformDelta(m->green_to_blue_, green); new_blue -= ColorTransformDelta(m->red_to_blue_, red); new_blue &= 0xff; data[i] = (argb & 0xff00ff00u) | (new_red << 16) | (new_blue); } } void VP8LTransformColorInverse_C(const VP8LMultipliers* const m, uint32_t* data, int num_pixels) { int i; for (i = 0; i < num_pixels; ++i) { const uint32_t argb = data[i]; const uint32_t green = argb >> 8; const uint32_t red = argb >> 16; uint32_t new_red = red; uint32_t new_blue = argb; new_red += ColorTransformDelta(m->green_to_red_, green); new_red &= 0xff; new_blue += ColorTransformDelta(m->green_to_blue_, green); new_blue += ColorTransformDelta(m->red_to_blue_, new_red); new_blue &= 0xff; data[i] = (argb & 0xff00ff00u) | (new_red << 16) | (new_blue); } } static WEBP_INLINE uint8_t TransformColorRed(uint8_t green_to_red, uint32_t argb) { const uint32_t green = argb >> 8; uint32_t new_red = argb >> 16; new_red -= ColorTransformDelta(green_to_red, green); return (new_red & 0xff); } static WEBP_INLINE uint8_t TransformColorBlue(uint8_t green_to_blue, uint8_t red_to_blue, uint32_t argb) { const uint32_t green = argb >> 8; const uint32_t red = argb >> 16; uint8_t new_blue = argb; new_blue -= ColorTransformDelta(green_to_blue, green); new_blue -= ColorTransformDelta(red_to_blue, red); return (new_blue & 0xff); } static float PredictionCostCrossColor(const int accumulated[256], const int counts[256]) { // Favor low entropy, locally and globally. // Favor small absolute values for PredictionCostSpatial static const double kExpValue = 2.4; return CombinedShannonEntropy(counts, accumulated) + PredictionCostSpatial(counts, 3, kExpValue); } static float GetPredictionCostCrossColorRed( int tile_x_offset, int tile_y_offset, int all_x_max, int all_y_max, int xsize, VP8LMultipliers prev_x, VP8LMultipliers prev_y, int green_to_red, const int accumulated_red_histo[256], const uint32_t* const argb) { int all_y; int histo[256] = { 0 }; float cur_diff; for (all_y = tile_y_offset; all_y < all_y_max; ++all_y) { int ix = all_y * xsize + tile_x_offset; int all_x; for (all_x = tile_x_offset; all_x < all_x_max; ++all_x, ++ix) { ++histo[TransformColorRed(green_to_red, argb[ix])]; // red. } } cur_diff = PredictionCostCrossColor(accumulated_red_histo, histo); if ((uint8_t)green_to_red == prev_x.green_to_red_) { cur_diff -= 3; // favor keeping the areas locally similar } if ((uint8_t)green_to_red == prev_y.green_to_red_) { cur_diff -= 3; // favor keeping the areas locally similar } if (green_to_red == 0) { cur_diff -= 3; } return cur_diff; } static void GetBestGreenToRed( int tile_x_offset, int tile_y_offset, int all_x_max, int all_y_max, int xsize, VP8LMultipliers prev_x, VP8LMultipliers prev_y, const int accumulated_red_histo[256], const uint32_t* const argb, VP8LMultipliers* const best_tx) { int min_green_to_red = -64; int max_green_to_red = 64; int green_to_red = 0; int eval_min = 1; int eval_max = 1; float cur_diff_min = MAX_DIFF_COST; float cur_diff_max = MAX_DIFF_COST; // Do a binary search to find the optimal green_to_red color transform. while (max_green_to_red - min_green_to_red > 2) { if (eval_min) { cur_diff_min = GetPredictionCostCrossColorRed( tile_x_offset, tile_y_offset, all_x_max, all_y_max, xsize, prev_x, prev_y, min_green_to_red, accumulated_red_histo, argb); eval_min = 0; } if (eval_max) { cur_diff_max = GetPredictionCostCrossColorRed( tile_x_offset, tile_y_offset, all_x_max, all_y_max, xsize, prev_x, prev_y, max_green_to_red, accumulated_red_histo, argb); eval_max = 0; } if (cur_diff_min < cur_diff_max) { green_to_red = min_green_to_red; max_green_to_red = (max_green_to_red + min_green_to_red) / 2; eval_max = 1; } else { green_to_red = max_green_to_red; min_green_to_red = (max_green_to_red + min_green_to_red) / 2; eval_min = 1; } } best_tx->green_to_red_ = green_to_red; } static float GetPredictionCostCrossColorBlue( int tile_x_offset, int tile_y_offset, int all_x_max, int all_y_max, int xsize, VP8LMultipliers prev_x, VP8LMultipliers prev_y, int green_to_blue, int red_to_blue, const int accumulated_blue_histo[256], const uint32_t* const argb) { int all_y; int histo[256] = { 0 }; float cur_diff; for (all_y = tile_y_offset; all_y < all_y_max; ++all_y) { int all_x; int ix = all_y * xsize + tile_x_offset; for (all_x = tile_x_offset; all_x < all_x_max; ++all_x, ++ix) { ++histo[TransformColorBlue(green_to_blue, red_to_blue, argb[ix])]; } } cur_diff = PredictionCostCrossColor(accumulated_blue_histo, histo); if ((uint8_t)green_to_blue == prev_x.green_to_blue_) { cur_diff -= 3; // favor keeping the areas locally similar } if ((uint8_t)green_to_blue == prev_y.green_to_blue_) { cur_diff -= 3; // favor keeping the areas locally similar } if ((uint8_t)red_to_blue == prev_x.red_to_blue_) { cur_diff -= 3; // favor keeping the areas locally similar } if ((uint8_t)red_to_blue == prev_y.red_to_blue_) { cur_diff -= 3; // favor keeping the areas locally similar } if (green_to_blue == 0) { cur_diff -= 3; } if (red_to_blue == 0) { cur_diff -= 3; } return cur_diff; } static void GetBestGreenRedToBlue( int tile_x_offset, int tile_y_offset, int all_x_max, int all_y_max, int xsize, VP8LMultipliers prev_x, VP8LMultipliers prev_y, int quality, const int accumulated_blue_histo[256], const uint32_t* const argb, VP8LMultipliers* const best_tx) { float best_diff = MAX_DIFF_COST; float cur_diff; const int step = (quality < 25) ? 32 : (quality > 50) ? 8 : 16; const int min_green_to_blue = -32; const int max_green_to_blue = 32; const int min_red_to_blue = -32; const int max_red_to_blue = 32; const int num_iters = (1 + (max_green_to_blue - min_green_to_blue) / step) * (1 + (max_red_to_blue - min_red_to_blue) / step); // Number of tries to get optimal green_to_blue & red_to_blue color transforms // after finding a local minima. const int max_tries_after_min = 4 + (num_iters >> 2); int num_tries_after_min = 0; int green_to_blue; for (green_to_blue = min_green_to_blue; green_to_blue <= max_green_to_blue && num_tries_after_min < max_tries_after_min; green_to_blue += step) { int red_to_blue; for (red_to_blue = min_red_to_blue; red_to_blue <= max_red_to_blue && num_tries_after_min < max_tries_after_min; red_to_blue += step) { cur_diff = GetPredictionCostCrossColorBlue( tile_x_offset, tile_y_offset, all_x_max, all_y_max, xsize, prev_x, prev_y, green_to_blue, red_to_blue, accumulated_blue_histo, argb); if (cur_diff < best_diff) { best_diff = cur_diff; best_tx->green_to_blue_ = green_to_blue; best_tx->red_to_blue_ = red_to_blue; num_tries_after_min = 0; } else { ++num_tries_after_min; } } } } static VP8LMultipliers GetBestColorTransformForTile( int tile_x, int tile_y, int bits, VP8LMultipliers prev_x, VP8LMultipliers prev_y, int quality, int xsize, int ysize, const int accumulated_red_histo[256], const int accumulated_blue_histo[256], const uint32_t* const argb) { const int max_tile_size = 1 << bits; const int tile_y_offset = tile_y * max_tile_size; const int tile_x_offset = tile_x * max_tile_size; const int all_x_max = GetMin(tile_x_offset + max_tile_size, xsize); const int all_y_max = GetMin(tile_y_offset + max_tile_size, ysize); VP8LMultipliers best_tx; MultipliersClear(&best_tx); GetBestGreenToRed(tile_x_offset, tile_y_offset, all_x_max, all_y_max, xsize, prev_x, prev_y, accumulated_red_histo, argb, &best_tx); GetBestGreenRedToBlue(tile_x_offset, tile_y_offset, all_x_max, all_y_max, xsize, prev_x, prev_y, quality, accumulated_blue_histo, argb, &best_tx); return best_tx; } static void CopyTileWithColorTransform(int xsize, int ysize, int tile_x, int tile_y, int max_tile_size, VP8LMultipliers color_transform, uint32_t* argb) { const int xscan = GetMin(max_tile_size, xsize - tile_x); int yscan = GetMin(max_tile_size, ysize - tile_y); argb += tile_y * xsize + tile_x; while (yscan-- > 0) { VP8LTransformColor(&color_transform, argb, xscan); argb += xsize; } } void VP8LColorSpaceTransform(int width, int height, int bits, int quality, uint32_t* const argb, uint32_t* image) { const int max_tile_size = 1 << bits; const int tile_xsize = VP8LSubSampleSize(width, bits); const int tile_ysize = VP8LSubSampleSize(height, bits); int accumulated_red_histo[256] = { 0 }; int accumulated_blue_histo[256] = { 0 }; int tile_x, tile_y; VP8LMultipliers prev_x, prev_y; MultipliersClear(&prev_y); MultipliersClear(&prev_x); for (tile_y = 0; tile_y < tile_ysize; ++tile_y) { for (tile_x = 0; tile_x < tile_xsize; ++tile_x) { int y; const int tile_x_offset = tile_x * max_tile_size; const int tile_y_offset = tile_y * max_tile_size; const int all_x_max = GetMin(tile_x_offset + max_tile_size, width); const int all_y_max = GetMin(tile_y_offset + max_tile_size, height); const int offset = tile_y * tile_xsize + tile_x; if (tile_y != 0) { ColorCodeToMultipliers(image[offset - tile_xsize], &prev_y); } prev_x = GetBestColorTransformForTile(tile_x, tile_y, bits, prev_x, prev_y, quality, width, height, accumulated_red_histo, accumulated_blue_histo, argb); image[offset] = MultipliersToColorCode(&prev_x); CopyTileWithColorTransform(width, height, tile_x_offset, tile_y_offset, max_tile_size, prev_x, argb); // Gather accumulated histogram data. for (y = tile_y_offset; y < all_y_max; ++y) { int ix = y * width + tile_x_offset; const int ix_end = ix + all_x_max - tile_x_offset; for (; ix < ix_end; ++ix) { const uint32_t pix = argb[ix]; if (ix >= 2 && pix == argb[ix - 2] && pix == argb[ix - 1]) { continue; // repeated pixels are handled by backward references } if (ix >= width + 2 && argb[ix - 2] == argb[ix - width - 2] && argb[ix - 1] == argb[ix - width - 1] && pix == argb[ix - width]) { continue; // repeated pixels are handled by backward references } ++accumulated_red_histo[(pix >> 16) & 0xff]; ++accumulated_blue_histo[(pix >> 0) & 0xff]; } } } } } // Color space inverse transform. static void ColorSpaceInverseTransform(const VP8LTransform* const transform, int y_start, int y_end, uint32_t* data) { const int width = transform->xsize_; const int tile_width = 1 << transform->bits_; const int mask = tile_width - 1; const int safe_width = width & ~mask; const int remaining_width = width - safe_width; const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_); int y = y_start; const uint32_t* pred_row = transform->data_ + (y >> transform->bits_) * tiles_per_row; while (y < y_end) { const uint32_t* pred = pred_row; VP8LMultipliers m = { 0, 0, 0 }; const uint32_t* const data_safe_end = data + safe_width; const uint32_t* const data_end = data + width; while (data < data_safe_end) { ColorCodeToMultipliers(*pred++, &m); VP8LTransformColorInverse(&m, data, tile_width); data += tile_width; } if (data < data_end) { // Left-overs using C-version. ColorCodeToMultipliers(*pred++, &m); VP8LTransformColorInverse(&m, data, remaining_width); data += remaining_width; } ++y; if ((y & mask) == 0) pred_row += tiles_per_row; } } // Separate out pixels packed together using pixel-bundling. // We define two methods for ARGB data (uint32_t) and alpha-only data (uint8_t). #define COLOR_INDEX_INVERSE(FUNC_NAME, TYPE, GET_INDEX, GET_VALUE) \ void FUNC_NAME(const VP8LTransform* const transform, \ int y_start, int y_end, const TYPE* src, TYPE* dst) { \ int y; \ const int bits_per_pixel = 8 >> transform->bits_; \ const int width = transform->xsize_; \ const uint32_t* const color_map = transform->data_; \ if (bits_per_pixel < 8) { \ const int pixels_per_byte = 1 << transform->bits_; \ const int count_mask = pixels_per_byte - 1; \ const uint32_t bit_mask = (1 << bits_per_pixel) - 1; \ for (y = y_start; y < y_end; ++y) { \ uint32_t packed_pixels = 0; \ int x; \ for (x = 0; x < width; ++x) { \ /* We need to load fresh 'packed_pixels' once every */ \ /* 'pixels_per_byte' increments of x. Fortunately, pixels_per_byte */ \ /* is a power of 2, so can just use a mask for that, instead of */ \ /* decrementing a counter. */ \ if ((x & count_mask) == 0) packed_pixels = GET_INDEX(*src++); \ *dst++ = GET_VALUE(color_map[packed_pixels & bit_mask]); \ packed_pixels >>= bits_per_pixel; \ } \ } \ } else { \ for (y = y_start; y < y_end; ++y) { \ int x; \ for (x = 0; x < width; ++x) { \ *dst++ = GET_VALUE(color_map[GET_INDEX(*src++)]); \ } \ } \ } \ } static WEBP_INLINE uint32_t GetARGBIndex(uint32_t idx) { return (idx >> 8) & 0xff; } static WEBP_INLINE uint8_t GetAlphaIndex(uint8_t idx) { return idx; } static WEBP_INLINE uint32_t GetARGBValue(uint32_t val) { return val; } static WEBP_INLINE uint8_t GetAlphaValue(uint32_t val) { return (val >> 8) & 0xff; } static COLOR_INDEX_INVERSE(ColorIndexInverseTransform, uint32_t, GetARGBIndex, GetARGBValue) COLOR_INDEX_INVERSE(VP8LColorIndexInverseTransformAlpha, uint8_t, GetAlphaIndex, GetAlphaValue) #undef COLOR_INDEX_INVERSE void VP8LInverseTransform(const VP8LTransform* const transform, int row_start, int row_end, const uint32_t* const in, uint32_t* const out) { const int width = transform->xsize_; assert(row_start < row_end); assert(row_end <= transform->ysize_); switch (transform->type_) { case SUBTRACT_GREEN: VP8LAddGreenToBlueAndRed(out, (row_end - row_start) * width); break; case PREDICTOR_TRANSFORM: PredictorInverseTransform(transform, row_start, row_end, out); if (row_end != transform->ysize_) { // The last predicted row in this iteration will be the top-pred row // for the first row in next iteration. memcpy(out - width, out + (row_end - row_start - 1) * width, width * sizeof(*out)); } break; case CROSS_COLOR_TRANSFORM: ColorSpaceInverseTransform(transform, row_start, row_end, out); break; case COLOR_INDEXING_TRANSFORM: if (in == out && transform->bits_ > 0) { // Move packed pixels to the end of unpacked region, so that unpacking // can occur seamlessly. // Also, note that this is the only transform that applies on // the effective width of VP8LSubSampleSize(xsize_, bits_). All other // transforms work on effective width of xsize_. const int out_stride = (row_end - row_start) * width; const int in_stride = (row_end - row_start) * VP8LSubSampleSize(transform->xsize_, transform->bits_); uint32_t* const src = out + out_stride - in_stride; memmove(src, out, in_stride * sizeof(*src)); ColorIndexInverseTransform(transform, row_start, row_end, src, out); } else { ColorIndexInverseTransform(transform, row_start, row_end, in, out); } break; } } //------------------------------------------------------------------------------ // Color space conversion. static int is_big_endian(void) { static const union { uint16_t w; uint8_t b[2]; } tmp = { 1 }; return (tmp.b[0] != 1); } void VP8LConvertBGRAToRGB_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; *dst++ = (argb >> 16) & 0xff; *dst++ = (argb >> 8) & 0xff; *dst++ = (argb >> 0) & 0xff; } } void VP8LConvertBGRAToRGBA_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; *dst++ = (argb >> 16) & 0xff; *dst++ = (argb >> 8) & 0xff; *dst++ = (argb >> 0) & 0xff; *dst++ = (argb >> 24) & 0xff; } } void VP8LConvertBGRAToRGBA4444_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; const uint8_t rg = ((argb >> 16) & 0xf0) | ((argb >> 12) & 0xf); const uint8_t ba = ((argb >> 0) & 0xf0) | ((argb >> 28) & 0xf); #ifdef WEBP_SWAP_16BIT_CSP *dst++ = ba; *dst++ = rg; #else *dst++ = rg; *dst++ = ba; #endif } } void VP8LConvertBGRAToRGB565_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; const uint8_t rg = ((argb >> 16) & 0xf8) | ((argb >> 13) & 0x7); const uint8_t gb = ((argb >> 5) & 0xe0) | ((argb >> 3) & 0x1f); #ifdef WEBP_SWAP_16BIT_CSP *dst++ = gb; *dst++ = rg; #else *dst++ = rg; *dst++ = gb; #endif } } void VP8LConvertBGRAToBGR_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; *dst++ = (argb >> 0) & 0xff; *dst++ = (argb >> 8) & 0xff; *dst++ = (argb >> 16) & 0xff; } } static void CopyOrSwap(const uint32_t* src, int num_pixels, uint8_t* dst, int swap_on_big_endian) { if (is_big_endian() == swap_on_big_endian) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; #if !defined(WORDS_BIGENDIAN) #if !defined(WEBP_REFERENCE_IMPLEMENTATION) *(uint32_t*)dst = BSwap32(argb); #else // WEBP_REFERENCE_IMPLEMENTATION dst[0] = (argb >> 24) & 0xff; dst[1] = (argb >> 16) & 0xff; dst[2] = (argb >> 8) & 0xff; dst[3] = (argb >> 0) & 0xff; #endif #else // WORDS_BIGENDIAN dst[0] = (argb >> 0) & 0xff; dst[1] = (argb >> 8) & 0xff; dst[2] = (argb >> 16) & 0xff; dst[3] = (argb >> 24) & 0xff; #endif dst += sizeof(argb); } } else { memcpy(dst, src, num_pixels * sizeof(*src)); } } void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels, WEBP_CSP_MODE out_colorspace, uint8_t* const rgba) { switch (out_colorspace) { case MODE_RGB: VP8LConvertBGRAToRGB(in_data, num_pixels, rgba); break; case MODE_RGBA: VP8LConvertBGRAToRGBA(in_data, num_pixels, rgba); break; case MODE_rgbA: VP8LConvertBGRAToRGBA(in_data, num_pixels, rgba); WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0); break; case MODE_BGR: VP8LConvertBGRAToBGR(in_data, num_pixels, rgba); break; case MODE_BGRA: CopyOrSwap(in_data, num_pixels, rgba, 1); break; case MODE_bgrA: CopyOrSwap(in_data, num_pixels, rgba, 1); WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0); break; case MODE_ARGB: CopyOrSwap(in_data, num_pixels, rgba, 0); break; case MODE_Argb: CopyOrSwap(in_data, num_pixels, rgba, 0); WebPApplyAlphaMultiply(rgba, 1, num_pixels, 1, 0); break; case MODE_RGBA_4444: VP8LConvertBGRAToRGBA4444(in_data, num_pixels, rgba); break; case MODE_rgbA_4444: VP8LConvertBGRAToRGBA4444(in_data, num_pixels, rgba); WebPApplyAlphaMultiply4444(rgba, num_pixels, 1, 0); break; case MODE_RGB_565: VP8LConvertBGRAToRGB565(in_data, num_pixels, rgba); break; default: assert(0); // Code flow should not reach here. } } //------------------------------------------------------------------------------ // Bundles multiple (1, 2, 4 or 8) pixels into a single pixel. void VP8LBundleColorMap(const uint8_t* const row, int width, int xbits, uint32_t* const dst) { int x; if (xbits > 0) { const int bit_depth = 1 << (3 - xbits); const int mask = (1 << xbits) - 1; uint32_t code = 0xff000000; for (x = 0; x < width; ++x) { const int xsub = x & mask; if (xsub == 0) { code = 0xff000000; } code |= row[x] << (8 + bit_depth * xsub); dst[x >> xbits] = code; } } else { for (x = 0; x < width; ++x) dst[x] = 0xff000000 | (row[x] << 8); } } //------------------------------------------------------------------------------ static double ExtraCost(const uint32_t* population, int length) { int i; double cost = 0.; for (i = 2; i < length - 2; ++i) cost += (i >> 1) * population[i + 2]; return cost; } static double ExtraCostCombined(const uint32_t* X, const uint32_t* Y, int length) { int i; double cost = 0.; for (i = 2; i < length - 2; ++i) { const int xy = X[i + 2] + Y[i + 2]; cost += (i >> 1) * xy; } return cost; } // Returns the various RLE counts static VP8LStreaks HuffmanCostCount(const uint32_t* population, int length) { int i; int streak = 0; VP8LStreaks stats; memset(&stats, 0, sizeof(stats)); for (i = 0; i < length - 1; ++i) { ++streak; if (population[i] == population[i + 1]) { continue; } stats.counts[population[i] != 0] += (streak > 3); stats.streaks[population[i] != 0][(streak > 3)] += streak; streak = 0; } ++streak; stats.counts[population[i] != 0] += (streak > 3); stats.streaks[population[i] != 0][(streak > 3)] += streak; return stats; } static VP8LStreaks HuffmanCostCombinedCount(const uint32_t* X, const uint32_t* Y, int length) { int i; int streak = 0; VP8LStreaks stats; memset(&stats, 0, sizeof(stats)); for (i = 0; i < length - 1; ++i) { const int xy = X[i] + Y[i]; const int xy_next = X[i + 1] + Y[i + 1]; ++streak; if (xy == xy_next) { continue; } stats.counts[xy != 0] += (streak > 3); stats.streaks[xy != 0][(streak > 3)] += streak; streak = 0; } { const int xy = X[i] + Y[i]; ++streak; stats.counts[xy != 0] += (streak > 3); stats.streaks[xy != 0][(streak > 3)] += streak; } return stats; } //------------------------------------------------------------------------------ static void HistogramAdd(const VP8LHistogram* const a, const VP8LHistogram* const b, VP8LHistogram* const out) { int i; const int literal_size = VP8LHistogramNumCodes(a->palette_code_bits_); assert(a->palette_code_bits_ == b->palette_code_bits_); if (b != out) { for (i = 0; i < literal_size; ++i) { out->literal_[i] = a->literal_[i] + b->literal_[i]; } for (i = 0; i < NUM_DISTANCE_CODES; ++i) { out->distance_[i] = a->distance_[i] + b->distance_[i]; } for (i = 0; i < NUM_LITERAL_CODES; ++i) { out->red_[i] = a->red_[i] + b->red_[i]; out->blue_[i] = a->blue_[i] + b->blue_[i]; out->alpha_[i] = a->alpha_[i] + b->alpha_[i]; } } else { for (i = 0; i < literal_size; ++i) { out->literal_[i] += a->literal_[i]; } for (i = 0; i < NUM_DISTANCE_CODES; ++i) { out->distance_[i] += a->distance_[i]; } for (i = 0; i < NUM_LITERAL_CODES; ++i) { out->red_[i] += a->red_[i]; out->blue_[i] += a->blue_[i]; out->alpha_[i] += a->alpha_[i]; } } } //------------------------------------------------------------------------------ VP8LProcessBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed; VP8LProcessBlueAndRedFunc VP8LAddGreenToBlueAndRed; VP8LPredictorFunc VP8LPredictors[16]; VP8LTransformColorFunc VP8LTransformColor; VP8LTransformColorFunc VP8LTransformColorInverse; VP8LConvertFunc VP8LConvertBGRAToRGB; VP8LConvertFunc VP8LConvertBGRAToRGBA; VP8LConvertFunc VP8LConvertBGRAToRGBA4444; VP8LConvertFunc VP8LConvertBGRAToRGB565; VP8LConvertFunc VP8LConvertBGRAToBGR; VP8LFastLog2SlowFunc VP8LFastLog2Slow; VP8LFastLog2SlowFunc VP8LFastSLog2Slow; VP8LCostFunc VP8LExtraCost; VP8LCostCombinedFunc VP8LExtraCostCombined; VP8LCostCountFunc VP8LHuffmanCostCount; VP8LCostCombinedCountFunc VP8LHuffmanCostCombinedCount; VP8LHistogramAddFunc VP8LHistogramAdd; extern void VP8LDspInitSSE2(void); extern void VP8LDspInitNEON(void); extern void VP8LDspInitMIPS32(void); void VP8LDspInit(void) { memcpy(VP8LPredictors, kPredictorsC, sizeof(VP8LPredictors)); VP8LSubtractGreenFromBlueAndRed = VP8LSubtractGreenFromBlueAndRed_C; VP8LAddGreenToBlueAndRed = VP8LAddGreenToBlueAndRed_C; VP8LTransformColor = VP8LTransformColor_C; VP8LTransformColorInverse = VP8LTransformColorInverse_C; VP8LConvertBGRAToRGB = VP8LConvertBGRAToRGB_C; VP8LConvertBGRAToRGBA = VP8LConvertBGRAToRGBA_C; VP8LConvertBGRAToRGBA4444 = VP8LConvertBGRAToRGBA4444_C; VP8LConvertBGRAToRGB565 = VP8LConvertBGRAToRGB565_C; VP8LConvertBGRAToBGR = VP8LConvertBGRAToBGR_C; VP8LFastLog2Slow = FastLog2Slow; VP8LFastSLog2Slow = FastSLog2Slow; VP8LExtraCost = ExtraCost; VP8LExtraCostCombined = ExtraCostCombined; VP8LHuffmanCostCount = HuffmanCostCount; VP8LHuffmanCostCombinedCount = HuffmanCostCombinedCount; VP8LHistogramAdd = HistogramAdd; // If defined, use CPUInfo() to overwrite some pointers with faster versions. if (VP8GetCPUInfo != NULL) { #if defined(WEBP_USE_SSE2) if (VP8GetCPUInfo(kSSE2)) { VP8LDspInitSSE2(); } #endif #if defined(WEBP_USE_NEON) if (VP8GetCPUInfo(kNEON)) { VP8LDspInitNEON(); } #endif #if defined(WEBP_USE_MIPS32) if (VP8GetCPUInfo(kMIPS32)) { VP8LDspInitMIPS32(); } #endif } } //------------------------------------------------------------------------------