Adding libwebp: Adding clean copy of libwebp 0.4.0

This commit imports libwebp 0.4.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

The patches required to build it in Qt will follow in separate
commit(s).

Task-number: QTBUG-14205
Change-Id: I747918fe2a07716f66cffb795129f7aa5e067759
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 1532 insertions, 0 deletions

diff --git a/src/3rdparty/libwebp/src/dsp/lossless.c b/src/3rdparty/libwebp/src/dsp/lossless.c
new file mode 100644
index 0000000..bab76d2
--- /dev/null
+++ b/src/3rdparty/libwebp/src/dsp/lossless.c
@@ -0,0 +1,1532 @@
+// 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"
+
+#if defined(WEBP_USE_SSE2)
+#include <emmintrin.h>
+#endif
+
+#include <math.h>
+#include <stdlib.h>
+#include "./lossless.h"
+#include "../dec/vp8li.h"
+#include "./yuv.h"
+
+#define MAX_DIFF_COST (1e30f)
+
+// lookup table for small values of log2(int)
+#define APPROX_LOG_MAX  4096
+#define LOG_2_RECIPROCAL 1.44269504088896338700465094007086
+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
+};
+
+float VP8LFastSLog2Slow(int v) {
+  assert(v >= LOG_LOOKUP_IDX_MAX);
+  if (v < APPROX_LOG_MAX) {
+    int log_cnt = 0;
+    const float v_f = (float)v;
+    while (v >= LOG_LOOKUP_IDX_MAX) {
+      ++log_cnt;
+      v = v >> 1;
+    }
+    return v_f * (kLog2Table[v] + log_cnt);
+  } else {
+    return (float)(LOG_2_RECIPROCAL * v * log((double)v));
+  }
+}
+
+float VP8LFastLog2Slow(int v) {
+  assert(v >= LOG_LOOKUP_IDX_MAX);
+  if (v < APPROX_LOG_MAX) {
+    int log_cnt = 0;
+    while (v >= LOG_LOOKUP_IDX_MAX) {
+      ++log_cnt;
+      v = v >> 1;
+    }
+    return kLog2Table[v] + log_cnt;
+  } else {
+    return (float)(LOG_2_RECIPROCAL * log((double)v));
+  }
+}
+
+//------------------------------------------------------------------------------
+// Image transforms.
+
+// 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 (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 (a << 24) | (r << 16) | (g << 8) | b;
+}
+
+static WEBP_INLINE int Sub3(int a, int b, int c) {
+  const int pb = b - c;
+  const int pa = a - c;
+  return abs(pb) - abs(pa);
+}
+
+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 = VP8LSelect(top[0], left, top[-1]);
+  return pred;
+}
+static uint32_t Predictor12(uint32_t left, const uint32_t* const top) {
+  const uint32_t pred = VP8LClampedAddSubtractFull(left, top[0], top[-1]);
+  return pred;
+}
+static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
+  const uint32_t pred = VP8LClampedAddSubtractHalf(left, top[0], top[-1]);
+  return pred;
+}
+
+// TODO(vikasa): Export the predictor array, to allow SSE2 variants.
+typedef uint32_t (*PredictorFunc)(uint32_t left, const uint32_t* const top);
+static const PredictorFunc kPredictors[16] = {
+  Predictor0, Predictor1, Predictor2, Predictor3,
+  Predictor4, Predictor5, Predictor6, Predictor7,
+  Predictor8, Predictor9, Predictor10, Predictor11,
+  Predictor12, Predictor13,
+  Predictor0, Predictor0    // <- padding security sentinels
+};
+
+// TODO(vikasa): Replace 256 etc with defines.
+static float PredictionCostSpatial(const int* counts,
+                                   int weight_0, double exp_val) {
+  const int significant_symbols = 16;
+  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* const X,
+                                    const int* const Y, int n) {
+  int i;
+  double retval = 0.;
+  int sumX = 0, sumXY = 0;
+  for (i = 0; i < n; ++i) {
+    const int x = X[i];
+    const int xy = X[i] + Y[i];
+    if (x != 0) {
+      sumX += x;
+      retval -= VP8LFastSLog2(x);
+    }
+    if (xy != 0) {
+      sumXY += xy;
+      retval -= VP8LFastSLog2(xy);
+    }
+  }
+  retval += VP8LFastSLog2(sumX) + VP8LFastSLog2(sumXY);
+  return (float)retval;
+}
+
+static float PredictionCostSpatialHistogram(int accumulated[4][256],
+                                            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], 256);
+  }
+  return (float)retval;
+}
+
+static int GetBestPredictorForTile(int width, int height,
+                                   int tile_x, int tile_y, int bits,
+                                   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 ymax = (tile_size <= height - row_start) ?
+      tile_size : height - row_start;
+  const int xmax = (tile_size <= width - col_start) ?
+      tile_size : width - col_start;
+  int histo[4][256];
+  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 PredictorFunc pred_func = kPredictors[mode];
+    float cur_diff;
+    int y;
+    memset(&histo[0][0], 0, sizeof(histo));
+    for (y = 0; y < ymax; ++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 < xmax; ++x) {
+        const int col = col_start + x;
+        uint32_t predict;
+        uint32_t predict_diff;
+        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);
+        }
+        predict_diff = VP8LSubPixels(current_row[col], predict);
+        ++histo[0][predict_diff >> 24];
+        ++histo[1][((predict_diff >> 16) & 0xff)];
+        ++histo[2][((predict_diff >> 8) & 0xff)];
+        ++histo[3][(predict_diff & 0xff)];
+      }
+    }
+    cur_diff = PredictionCostSpatialHistogram(accumulated, histo);
+    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 ymax = (tile_size <= height - row_start) ?
+      tile_size : height - row_start;
+  const int xmax = (tile_size <= width - col_start) ?
+      tile_size : width - col_start;
+  const PredictorFunc pred_func = kPredictors[mode];
+  const uint32_t* current_row = argb_scratch;
+
+  int y;
+  for (y = 0; y < ymax; ++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 < xmax; ++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, 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) {
+          const uint32_t a = argb[ix];
+          ++histo[0][a >> 24];
+          ++histo[1][((a >> 16) & 0xff)];
+          ++histo[2][((a >> 8) & 0xff)];
+          ++histo[3][(a & 0xff)];
+        }
+      }
+    }
+  }
+}
+
+// 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 mask = (1 << transform->bits_) - 1;
+    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) {
+      int x;
+      const uint32_t pred2 = Predictor2(data[-1], data - width);
+      const uint32_t* pred_mode_src = pred_mode_base;
+      PredictorFunc pred_func;
+
+      // First pixel follows the T (mode=2) mode.
+      AddPixelsEq(data, pred2);
+
+      // .. the rest:
+      pred_func = kPredictors[((*pred_mode_src++) >> 8) & 0xf];
+      for (x = 1; x < width; ++x) {
+        uint32_t pred;
+        if ((x & mask) == 0) {    // start of tile. Read predictor function.
+          pred_func = kPredictors[((*pred_mode_src++) >> 8) & 0xf];
+        }
+        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;
+      }
+    }
+  }
+}
+
+static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixs) {
+  int i = 0;
+  for (; i < num_pixs; ++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').
+static void AddGreenToBlueAndRed(uint32_t* data, const uint32_t* data_end) {
+  while (data < data_end) {
+    const uint32_t argb = *data;
+    const uint32_t green = ((argb >> 8) & 0xff);
+    uint32_t red_blue = (argb & 0x00ff00ffu);
+    red_blue += (green << 16) | green;
+    red_blue &= 0x00ff00ffu;
+    *data++ = (argb & 0xff00ff00u) | red_blue;
+  }
+}
+
+typedef struct {
+  // Note: the members are uint8_t, so that any negative values are
+  // automatically converted to "mod 256" values.
+  uint8_t green_to_red_;
+  uint8_t green_to_blue_;
+  uint8_t red_to_blue_;
+} Multipliers;
+
+static WEBP_INLINE void MultipliersClear(Multipliers* 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,
+                                               Multipliers* 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(Multipliers* const m) {
+  return 0xff000000u |
+         ((uint32_t)(m->red_to_blue_) << 16) |
+         ((uint32_t)(m->green_to_blue_) << 8) |
+         m->green_to_red_;
+}
+
+static WEBP_INLINE uint32_t TransformColor(const Multipliers* const m,
+                                           uint32_t argb, int inverse) {
+  const uint32_t green = argb >> 8;
+  const uint32_t red = argb >> 16;
+  uint32_t new_red = red;
+  uint32_t new_blue = argb;
+
+  if (inverse) {
+    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;
+  } else {
+    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;
+  }
+  return (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 WEBP_INLINE int SkipRepeatedPixels(const uint32_t* const argb,
+                                          int ix, int xsize) {
+  const uint32_t v = argb[ix];
+  if (ix >= xsize + 3) {
+    if (v == argb[ix - xsize] &&
+        argb[ix - 1] == argb[ix - xsize - 1] &&
+        argb[ix - 2] == argb[ix - xsize - 2] &&
+        argb[ix - 3] == argb[ix - xsize - 3]) {
+      return 1;
+    }
+    return v == argb[ix - 3] && v == argb[ix - 2] && v == argb[ix - 1];
+  } else if (ix >= 3) {
+    return v == argb[ix - 3] && v == argb[ix - 2] && v == argb[ix - 1];
+  }
+  return 0;
+}
+
+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, 256) +
+         PredictionCostSpatial(counts, 3, kExpValue);
+}
+
+static Multipliers GetBestColorTransformForTile(
+    int tile_x, int tile_y, int bits,
+    Multipliers prevX,
+    Multipliers prevY,
+    int step, int xsize, int ysize,
+    int* accumulated_red_histo,
+    int* accumulated_blue_histo,
+    const uint32_t* const argb) {
+  float best_diff = MAX_DIFF_COST;
+  float cur_diff;
+  const int halfstep = step / 2;
+  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;
+  int green_to_red;
+  int green_to_blue;
+  int red_to_blue;
+  int all_x_max = tile_x_offset + max_tile_size;
+  int all_y_max = tile_y_offset + max_tile_size;
+  Multipliers best_tx;
+  MultipliersClear(&best_tx);
+  if (all_x_max > xsize) {
+    all_x_max = xsize;
+  }
+  if (all_y_max > ysize) {
+    all_y_max = ysize;
+  }
+
+  for (green_to_red = -64; green_to_red <= 64; green_to_red += halfstep) {
+    int histo[256] = { 0 };
+    int all_y;
+
+    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) {
+        if (SkipRepeatedPixels(argb, ix, xsize)) {
+          continue;
+        }
+        ++histo[TransformColorRed(green_to_red, argb[ix])];  // red.
+      }
+    }
+    cur_diff = PredictionCostCrossColor(&accumulated_red_histo[0], &histo[0]);
+    if ((uint8_t)green_to_red == prevX.green_to_red_) {
+      cur_diff -= 3;  // favor keeping the areas locally similar
+    }
+    if ((uint8_t)green_to_red == prevY.green_to_red_) {
+      cur_diff -= 3;  // favor keeping the areas locally similar
+    }
+    if (green_to_red == 0) {
+      cur_diff -= 3;
+    }
+    if (cur_diff < best_diff) {
+      best_diff = cur_diff;
+      best_tx.green_to_red_ = green_to_red;
+    }
+  }
+  best_diff = MAX_DIFF_COST;
+  for (green_to_blue = -32; green_to_blue <= 32; green_to_blue += step) {
+    for (red_to_blue = -32; red_to_blue <= 32; red_to_blue += step) {
+      int all_y;
+      int histo[256] = { 0 };
+      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) {
+          if (SkipRepeatedPixels(argb, ix, xsize)) {
+            continue;
+          }
+          ++histo[TransformColorBlue(green_to_blue, red_to_blue, argb[ix])];
+        }
+      }
+      cur_diff =
+          PredictionCostCrossColor(&accumulated_blue_histo[0], &histo[0]);
+      if ((uint8_t)green_to_blue == prevX.green_to_blue_) {
+        cur_diff -= 3;  // favor keeping the areas locally similar
+      }
+      if ((uint8_t)green_to_blue == prevY.green_to_blue_) {
+        cur_diff -= 3;  // favor keeping the areas locally similar
+      }
+      if ((uint8_t)red_to_blue == prevX.red_to_blue_) {
+        cur_diff -= 3;  // favor keeping the areas locally similar
+      }
+      if ((uint8_t)red_to_blue == prevY.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;
+      }
+      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;
+      }
+    }
+  }
+  return best_tx;
+}
+
+static void CopyTileWithColorTransform(int xsize, int ysize,
+                                       int tile_x, int tile_y, int bits,
+                                       Multipliers color_transform,
+                                       uint32_t* const argb) {
+  int y;
+  int xscan = 1 << bits;
+  int yscan = 1 << bits;
+  tile_x <<= bits;
+  tile_y <<= bits;
+  if (xscan > xsize - tile_x) {
+    xscan = xsize - tile_x;
+  }
+  if (yscan > ysize - tile_y) {
+    yscan = ysize - tile_y;
+  }
+  yscan += tile_y;
+  for (y = tile_y; y < yscan; ++y) {
+    int ix = y * xsize + tile_x;
+    const int end_ix = ix + xscan;
+    for (; ix < end_ix; ++ix) {
+      argb[ix] = TransformColor(&color_transform, argb[ix], 0);
+    }
+  }
+}
+
+void VP8LColorSpaceTransform(int width, int height, int bits, int step,
+                             uint32_t* const argb, uint32_t* image) {
+  const int max_tile_size = 1 << bits;
+  int tile_xsize = VP8LSubSampleSize(width, bits);
+  int tile_ysize = VP8LSubSampleSize(height, bits);
+  int accumulated_red_histo[256] = { 0 };
+  int accumulated_blue_histo[256] = { 0 };
+  int tile_y;
+  int tile_x;
+  Multipliers prevX;
+  Multipliers prevY;
+  MultipliersClear(&prevY);
+  MultipliersClear(&prevX);
+  for (tile_y = 0; tile_y < tile_ysize; ++tile_y) {
+    for (tile_x = 0; tile_x < tile_xsize; ++tile_x) {
+      Multipliers color_transform;
+      int all_x_max;
+      int y;
+      const int tile_y_offset = tile_y * max_tile_size;
+      const int tile_x_offset = tile_x * max_tile_size;
+      if (tile_y != 0) {
+        ColorCodeToMultipliers(image[tile_y * tile_xsize + tile_x - 1], &prevX);
+        ColorCodeToMultipliers(image[(tile_y - 1) * tile_xsize + tile_x],
+                               &prevY);
+      } else if (tile_x != 0) {
+        ColorCodeToMultipliers(image[tile_y * tile_xsize + tile_x - 1], &prevX);
+      }
+      color_transform =
+          GetBestColorTransformForTile(tile_x, tile_y, bits,
+                                       prevX, prevY,
+                                       step, width, height,
+                                       &accumulated_red_histo[0],
+                                       &accumulated_blue_histo[0],
+                                       argb);
+      image[tile_y * tile_xsize + tile_x] =
+          MultipliersToColorCode(&color_transform);
+      CopyTileWithColorTransform(width, height, tile_x, tile_y, bits,
+                                 color_transform, argb);
+
+      // Gather accumulated histogram data.
+      all_x_max = tile_x_offset + max_tile_size;
+      if (all_x_max > width) {
+        all_x_max = width;
+      }
+      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) {
+          if (ix >= 2 &&
+              argb[ix] == argb[ix - 2] &&
+              argb[ix] == 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] &&
+              argb[ix] == argb[ix - width]) {
+            continue;  // repeated pixels are handled by backward references
+          }
+          ++accumulated_red_histo[(argb[ix] >> 16) & 0xff];
+          ++accumulated_blue_histo[argb[ix] & 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 mask = (1 << transform->bits_) - 1;
+  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;
+    Multipliers m = { 0, 0, 0 };
+    int x;
+
+    for (x = 0; x < width; ++x) {
+      if ((x & mask) == 0) ColorCodeToMultipliers(*pred++, &m);
+      data[x] = TransformColor(&m, data[x], 1);
+    }
+    data += 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, 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);
+}
+
+static void ConvertBGRAToRGB(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;
+  }
+}
+
+static void ConvertBGRAToRGBA(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;
+  }
+}
+
+static void ConvertBGRAToRGBA4444(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
+  }
+}
+
+static void ConvertBGRAToRGB565(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
+  }
+}
+
+static void ConvertBGRAToBGR(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) {
+      uint32_t argb = *src++;
+
+#if !defined(__BIG_ENDIAN__)
+#if !defined(WEBP_REFERENCE_IMPLEMENTATION)
+#if defined(__i386__) || defined(__x86_64__)
+      __asm__ volatile("bswap %0" : "=r"(argb) : "0"(argb));
+      *(uint32_t*)dst = argb;
+#elif defined(_MSC_VER)
+      argb = _byteswap_ulong(argb);
+      *(uint32_t*)dst = argb;
+#else
+      dst[0] = (argb >> 24) & 0xff;
+      dst[1] = (argb >> 16) & 0xff;
+      dst[2] = (argb >>  8) & 0xff;
+      dst[3] = (argb >>  0) & 0xff;
+#endif
+#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  // __BIG_ENDIAN__
+      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:
+      ConvertBGRAToRGB(in_data, num_pixels, rgba);
+      break;
+    case MODE_RGBA:
+      ConvertBGRAToRGBA(in_data, num_pixels, rgba);
+      break;
+    case MODE_rgbA:
+      ConvertBGRAToRGBA(in_data, num_pixels, rgba);
+      WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0);
+      break;
+    case MODE_BGR:
+      ConvertBGRAToBGR(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:
+      ConvertBGRAToRGBA4444(in_data, num_pixels, rgba);
+      break;
+    case MODE_rgbA_4444:
+      ConvertBGRAToRGBA4444(in_data, num_pixels, rgba);
+      WebPApplyAlphaMultiply4444(rgba, num_pixels, 1, 0);
+      break;
+    case MODE_RGB_565:
+      ConvertBGRAToRGB565(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);
+  }
+}
+
+//------------------------------------------------------------------------------
+
+// TODO(vikasa): Move the SSE2 functions to lossless_dsp.c (new file), once
+// color-space conversion methods (ConvertFromBGRA) are also updated for SSE2.
+#if defined(WEBP_USE_SSE2)
+static WEBP_INLINE uint32_t ClampedAddSubtractFullSSE2(uint32_t c0, uint32_t c1,
+                                                       uint32_t c2) {
+  const __m128i zero = _mm_setzero_si128();
+  const __m128i C0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128(c0), zero);
+  const __m128i C1 = _mm_unpacklo_epi8(_mm_cvtsi32_si128(c1), zero);
+  const __m128i C2 = _mm_unpacklo_epi8(_mm_cvtsi32_si128(c2), zero);
+  const __m128i V1 = _mm_add_epi16(C0, C1);
+  const __m128i V2 = _mm_sub_epi16(V1, C2);
+  const __m128i b = _mm_packus_epi16(V2, V2);
+  const uint32_t output = _mm_cvtsi128_si32(b);
+  return output;
+}
+
+static WEBP_INLINE uint32_t ClampedAddSubtractHalfSSE2(uint32_t c0, uint32_t c1,
+                                                       uint32_t c2) {
+  const uint32_t ave = Average2(c0, c1);
+  const __m128i zero = _mm_setzero_si128();
+  const __m128i A0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128(ave), zero);
+  const __m128i B0 = _mm_unpacklo_epi8(_mm_cvtsi32_si128(c2), zero);
+  const __m128i A1 = _mm_sub_epi16(A0, B0);
+  const __m128i BgtA = _mm_cmpgt_epi16(B0, A0);
+  const __m128i A2 = _mm_sub_epi16(A1, BgtA);
+  const __m128i A3 = _mm_srai_epi16(A2, 1);
+  const __m128i A4 = _mm_add_epi16(A0, A3);
+  const __m128i A5 = _mm_packus_epi16(A4, A4);
+  const uint32_t output = _mm_cvtsi128_si32(A5);
+  return output;
+}
+
+static WEBP_INLINE uint32_t SelectSSE2(uint32_t a, uint32_t b, uint32_t c) {
+  int pa_minus_pb;
+  const __m128i zero = _mm_setzero_si128();
+  const __m128i A0 = _mm_cvtsi32_si128(a);
+  const __m128i B0 = _mm_cvtsi32_si128(b);
+  const __m128i C0 = _mm_cvtsi32_si128(c);
+  const __m128i AC0 = _mm_subs_epu8(A0, C0);
+  const __m128i CA0 = _mm_subs_epu8(C0, A0);
+  const __m128i BC0 = _mm_subs_epu8(B0, C0);
+  const __m128i CB0 = _mm_subs_epu8(C0, B0);
+  const __m128i AC = _mm_or_si128(AC0, CA0);
+  const __m128i BC = _mm_or_si128(BC0, CB0);
+  const __m128i pa = _mm_unpacklo_epi8(AC, zero);  // |a - c|
+  const __m128i pb = _mm_unpacklo_epi8(BC, zero);  // |b - c|
+  const __m128i diff = _mm_sub_epi16(pb, pa);
+  {
+    int16_t out[8];
+    _mm_storeu_si128((__m128i*)out, diff);
+    pa_minus_pb = out[0] + out[1] + out[2] + out[3];
+  }
+  return (pa_minus_pb <= 0) ? a : b;
+}
+
+static void SubtractGreenFromBlueAndRedSSE2(uint32_t* argb_data, int num_pixs) {
+  int i = 0;
+  const __m128i mask = _mm_set1_epi32(0x0000ff00);
+  for (; i + 4 < num_pixs; i += 4) {
+    const __m128i in = _mm_loadu_si128((__m128i*)&argb_data[i]);
+    const __m128i in_00g0 = _mm_and_si128(in, mask);     // 00g0|00g0|...
+    const __m128i in_0g00 = _mm_slli_epi32(in_00g0, 8);  // 0g00|0g00|...
+    const __m128i in_000g = _mm_srli_epi32(in_00g0, 8);  // 000g|000g|...
+    const __m128i in_0g0g = _mm_or_si128(in_0g00, in_000g);
+    const __m128i out = _mm_sub_epi8(in, in_0g0g);
+    _mm_storeu_si128((__m128i*)&argb_data[i], out);
+  }
+  // fallthrough and finish off with plain-C
+  for (; i < num_pixs; ++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;
+  }
+}
+
+static void AddGreenToBlueAndRedSSE2(uint32_t* data, const uint32_t* data_end) {
+  const __m128i mask = _mm_set1_epi32(0x0000ff00);
+  for (; data + 4 < data_end; data += 4) {
+    const __m128i in = _mm_loadu_si128((__m128i*)data);
+    const __m128i in_00g0 = _mm_and_si128(in, mask);     // 00g0|00g0|...
+    const __m128i in_0g00 = _mm_slli_epi32(in_00g0, 8);  // 0g00|0g00|...
+    const __m128i in_000g = _mm_srli_epi32(in_00g0, 8);  // 000g|000g|...
+    const __m128i in_0g0g = _mm_or_si128(in_0g00, in_000g);
+    const __m128i out = _mm_add_epi8(in, in_0g0g);
+    _mm_storeu_si128((__m128i*)data, out);
+  }
+  // fallthrough and finish off with plain-C
+  while (data < data_end) {
+    const uint32_t argb = *data;
+    const uint32_t green = ((argb >> 8) & 0xff);
+    uint32_t red_blue = (argb & 0x00ff00ffu);
+    red_blue += (green << 16) | green;
+    red_blue &= 0x00ff00ffu;
+    *data++ = (argb & 0xff00ff00u) | red_blue;
+  }
+}
+
+extern void VP8LDspInitSSE2(void);
+
+void VP8LDspInitSSE2(void) {
+  VP8LClampedAddSubtractFull = ClampedAddSubtractFullSSE2;
+  VP8LClampedAddSubtractHalf = ClampedAddSubtractHalfSSE2;
+  VP8LSelect = SelectSSE2;
+  VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRedSSE2;
+  VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRedSSE2;
+}
+#endif
+//------------------------------------------------------------------------------
+
+VP8LPredClampedAddSubFunc VP8LClampedAddSubtractFull;
+VP8LPredClampedAddSubFunc VP8LClampedAddSubtractHalf;
+VP8LPredSelectFunc VP8LSelect;
+VP8LSubtractGreenFromBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
+VP8LAddGreenToBlueAndRedFunc VP8LAddGreenToBlueAndRed;
+
+void VP8LDspInit(void) {
+  VP8LClampedAddSubtractFull = ClampedAddSubtractFull;
+  VP8LClampedAddSubtractHalf = ClampedAddSubtractHalf;
+  VP8LSelect = Select;
+  VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed;
+  VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed;
+
+  // If defined, use CPUInfo() to overwrite some pointers with faster versions.
+  if (VP8GetCPUInfo != NULL) {
+#if defined(WEBP_USE_SSE2)
+    if (VP8GetCPUInfo(kSSE2)) {
+      VP8LDspInitSSE2();
+    }
+#endif
+  }
+}
+
+//------------------------------------------------------------------------------
+