Use the upstream version of libwebp, v0.4.3.

third_party/libwebp/dsp/dec.c

+// Copyright 2010 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.
+// -----------------------------------------------------------------------------
+//
+// Speed-critical decoding functions.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./dsp.h"
+#include "../dec/vp8i.h"
+
+//------------------------------------------------------------------------------
+
+static WEBP_INLINE uint8_t clip_8b(int v) {
+  return (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255;
+}
+
+//------------------------------------------------------------------------------
+// Transforms (Paragraph 14.4)
+
+#define STORE(x, y, v) \
+  dst[x + y * BPS] = clip_8b(dst[x + y * BPS] + ((v) >> 3))
+
+#define STORE2(y, dc, d, c) do {    \
+  const int DC = (dc);              \
+  STORE(0, y, DC + (d));            \
+  STORE(1, y, DC + (c));            \
+  STORE(2, y, DC - (c));            \
+  STORE(3, y, DC - (d));            \
+} while (0)
+
+static const int kC1 = 20091 + (1 << 16);
+static const int kC2 = 35468;
+#define MUL(a, b) (((a) * (b)) >> 16)
+
+static void TransformOne(const int16_t* in, uint8_t* dst) {
+  int C[4 * 4], *tmp;
+  int i;
+  tmp = C;
+  for (i = 0; i < 4; ++i) {    // vertical pass
+    const int a = in[0] + in[8];    // [-4096, 4094]
+    const int b = in[0] - in[8];    // [-4095, 4095]
+    const int c = MUL(in[4], kC2) - MUL(in[12], kC1);   // [-3783, 3783]
+    const int d = MUL(in[4], kC1) + MUL(in[12], kC2);   // [-3785, 3781]
+    tmp[0] = a + d;   // [-7881, 7875]
+    tmp[1] = b + c;   // [-7878, 7878]
+    tmp[2] = b - c;   // [-7878, 7878]
+    tmp[3] = a - d;   // [-7877, 7879]
+    tmp += 4;
+    in++;
+  }
+  // Each pass is expanding the dynamic range by ~3.85 (upper bound).
+  // The exact value is (2. + (kC1 + kC2) / 65536).
+  // After the second pass, maximum interval is [-3794, 3794], assuming
+  // an input in [-2048, 2047] interval. We then need to add a dst value
+  // in the [0, 255] range.
+  // In the worst case scenario, the input to clip_8b() can be as large as
+  // [-60713, 60968].
+  tmp = C;
+  for (i = 0; i < 4; ++i) {    // horizontal pass
+    const int dc = tmp[0] + 4;
+    const int a =  dc +  tmp[8];
+    const int b =  dc -  tmp[8];
+    const int c = MUL(tmp[4], kC2) - MUL(tmp[12], kC1);
+    const int d = MUL(tmp[4], kC1) + MUL(tmp[12], kC2);
+    STORE(0, 0, a + d);
+    STORE(1, 0, b + c);
+    STORE(2, 0, b - c);
+    STORE(3, 0, a - d);
+    tmp++;
+    dst += BPS;
+  }
+}
+
+// Simplified transform when only in[0], in[1] and in[4] are non-zero
+static void TransformAC3(const int16_t* in, uint8_t* dst) {
+  const int a = in[0] + 4;
+  const int c4 = MUL(in[4], kC2);
+  const int d4 = MUL(in[4], kC1);
+  const int c1 = MUL(in[1], kC2);
+  const int d1 = MUL(in[1], kC1);
+  STORE2(0, a + d4, d1, c1);
+  STORE2(1, a + c4, d1, c1);
+  STORE2(2, a - c4, d1, c1);
+  STORE2(3, a - d4, d1, c1);
+}
+#undef MUL
+#undef STORE2
+
+static void TransformTwo(const int16_t* in, uint8_t* dst, int do_two) {
+  TransformOne(in, dst);
+  if (do_two) {
+    TransformOne(in + 16, dst + 4);
+  }
+}
+
+static void TransformUV(const int16_t* in, uint8_t* dst) {
+  VP8Transform(in + 0 * 16, dst, 1);
+  VP8Transform(in + 2 * 16, dst + 4 * BPS, 1);
+}
+
+static void TransformDC(const int16_t *in, uint8_t* dst) {
+  const int DC = in[0] + 4;
+  int i, j;
+  for (j = 0; j < 4; ++j) {
+    for (i = 0; i < 4; ++i) {
+      STORE(i, j, DC);
+    }
+  }
+}
+
+static void TransformDCUV(const int16_t* in, uint8_t* dst) {
+  if (in[0 * 16]) VP8TransformDC(in + 0 * 16, dst);
+  if (in[1 * 16]) VP8TransformDC(in + 1 * 16, dst + 4);
+  if (in[2 * 16]) VP8TransformDC(in + 2 * 16, dst + 4 * BPS);
+  if (in[3 * 16]) VP8TransformDC(in + 3 * 16, dst + 4 * BPS + 4);
+}
+
+#undef STORE
+
+//------------------------------------------------------------------------------
+// Paragraph 14.3
+
+static void TransformWHT(const int16_t* in, int16_t* out) {
+  int tmp[16];
+  int i;
+  for (i = 0; i < 4; ++i) {
+    const int a0 = in[0 + i] + in[12 + i];
+    const int a1 = in[4 + i] + in[ 8 + i];
+    const int a2 = in[4 + i] - in[ 8 + i];
+    const int a3 = in[0 + i] - in[12 + i];
+    tmp[0  + i] = a0 + a1;
+    tmp[8  + i] = a0 - a1;
+    tmp[4  + i] = a3 + a2;
+    tmp[12 + i] = a3 - a2;
+  }
+  for (i = 0; i < 4; ++i) {
+    const int dc = tmp[0 + i * 4] + 3;    // w/ rounder
+    const int a0 = dc             + tmp[3 + i * 4];
+    const int a1 = tmp[1 + i * 4] + tmp[2 + i * 4];
+    const int a2 = tmp[1 + i * 4] - tmp[2 + i * 4];
+    const int a3 = dc             - tmp[3 + i * 4];
+    out[ 0] = (a0 + a1) >> 3;
+    out[16] = (a3 + a2) >> 3;
+    out[32] = (a0 - a1) >> 3;
+    out[48] = (a3 - a2) >> 3;
+    out += 64;
+  }
+}
+
+void (*VP8TransformWHT)(const int16_t* in, int16_t* out);
+
+//------------------------------------------------------------------------------
+// Intra predictions
+
+#define DST(x, y) dst[(x) + (y) * BPS]
+
+static WEBP_INLINE void TrueMotion(uint8_t *dst, int size) {
+  const uint8_t* top = dst - BPS;
+  const uint8_t* const clip0 = VP8kclip1 - top[-1];
+  int y;
+  for (y = 0; y < size; ++y) {
+    const uint8_t* const clip = clip0 + dst[-1];
+    int x;
+    for (x = 0; x < size; ++x) {
+      dst[x] = clip[top[x]];
+    }
+    dst += BPS;
+  }
+}
+static void TM4(uint8_t *dst)   { TrueMotion(dst, 4); }
+static void TM8uv(uint8_t *dst) { TrueMotion(dst, 8); }
+static void TM16(uint8_t *dst)  { TrueMotion(dst, 16); }
+
+//------------------------------------------------------------------------------
+// 16x16
+
+static void VE16(uint8_t *dst) {     // vertical
+  int j;
+  for (j = 0; j < 16; ++j) {
+    memcpy(dst + j * BPS, dst - BPS, 16);
+  }
+}
+
+static void HE16(uint8_t *dst) {     // horizontal
+  int j;
+  for (j = 16; j > 0; --j) {
+    memset(dst, dst[-1], 16);
+    dst += BPS;
+  }
+}
+
+static WEBP_INLINE void Put16(int v, uint8_t* dst) {
+  int j;
+  for (j = 0; j < 16; ++j) {
+    memset(dst + j * BPS, v, 16);
+  }
+}
+
+static void DC16(uint8_t *dst) {    // DC
+  int DC = 16;
+  int j;
+  for (j = 0; j < 16; ++j) {
+    DC += dst[-1 + j * BPS] + dst[j - BPS];
+  }
+  Put16(DC >> 5, dst);
+}
+
+static void DC16NoTop(uint8_t *dst) {   // DC with top samples not available
+  int DC = 8;
+  int j;
+  for (j = 0; j < 16; ++j) {
+    DC += dst[-1 + j * BPS];
+  }
+  Put16(DC >> 4, dst);
+}
+
+static void DC16NoLeft(uint8_t *dst) {  // DC with left samples not available
+  int DC = 8;
+  int i;
+  for (i = 0; i < 16; ++i) {
+    DC += dst[i - BPS];
+  }
+  Put16(DC >> 4, dst);
+}
+
+static void DC16NoTopLeft(uint8_t *dst) {  // DC with no top and left samples
+  Put16(0x80, dst);
+}
+
+//------------------------------------------------------------------------------
+// 4x4
+
+#define AVG3(a, b, c) (((a) + 2 * (b) + (c) + 2) >> 2)
+#define AVG2(a, b) (((a) + (b) + 1) >> 1)
+
+static void VE4(uint8_t *dst) {    // vertical
+  const uint8_t* top = dst - BPS;
+  const uint8_t vals[4] = {
+    AVG3(top[-1], top[0], top[1]),
+    AVG3(top[ 0], top[1], top[2]),
+    AVG3(top[ 1], top[2], top[3]),
+    AVG3(top[ 2], top[3], top[4])
+  };
+  int i;
+  for (i = 0; i < 4; ++i) {
+    memcpy(dst + i * BPS, vals, sizeof(vals));
+  }
+}
+
+static void HE4(uint8_t *dst) {    // horizontal
+  const int A = dst[-1 - BPS];
+  const int B = dst[-1];
+  const int C = dst[-1 + BPS];
+  const int D = dst[-1 + 2 * BPS];
+  const int E = dst[-1 + 3 * BPS];
+  *(uint32_t*)(dst + 0 * BPS) = 0x01010101U * AVG3(A, B, C);
+  *(uint32_t*)(dst + 1 * BPS) = 0x01010101U * AVG3(B, C, D);
+  *(uint32_t*)(dst + 2 * BPS) = 0x01010101U * AVG3(C, D, E);
+  *(uint32_t*)(dst + 3 * BPS) = 0x01010101U * AVG3(D, E, E);
+}
+
+static void DC4(uint8_t *dst) {   // DC
+  uint32_t dc = 4;
+  int i;
+  for (i = 0; i < 4; ++i) dc += dst[i - BPS] + dst[-1 + i * BPS];
+  dc >>= 3;
+  for (i = 0; i < 4; ++i) memset(dst + i * BPS, dc, 4);
+}
+
+static void RD4(uint8_t *dst) {   // Down-right
+  const int I = dst[-1 + 0 * BPS];
+  const int J = dst[-1 + 1 * BPS];
+  const int K = dst[-1 + 2 * BPS];
+  const int L = dst[-1 + 3 * BPS];
+  const int X = dst[-1 - BPS];
+  const int A = dst[0 - BPS];
+  const int B = dst[1 - BPS];
+  const int C = dst[2 - BPS];
+  const int D = dst[3 - BPS];
+  DST(0, 3)                                     = AVG3(J, K, L);
+  DST(0, 2) = DST(1, 3)                         = AVG3(I, J, K);
+  DST(0, 1) = DST(1, 2) = DST(2, 3)             = AVG3(X, I, J);
+  DST(0, 0) = DST(1, 1) = DST(2, 2) = DST(3, 3) = AVG3(A, X, I);
+  DST(1, 0) = DST(2, 1) = DST(3, 2)             = AVG3(B, A, X);
+  DST(2, 0) = DST(3, 1)                         = AVG3(C, B, A);
+  DST(3, 0)                                     = AVG3(D, C, B);
+}
+
+static void LD4(uint8_t *dst) {   // Down-Left
+  const int A = dst[0 - BPS];
+  const int B = dst[1 - BPS];
+  const int C = dst[2 - BPS];
+  const int D = dst[3 - BPS];
+  const int E = dst[4 - BPS];
+  const int F = dst[5 - BPS];
+  const int G = dst[6 - BPS];
+  const int H = dst[7 - BPS];
+  DST(0, 0)                                     = AVG3(A, B, C);
+  DST(1, 0) = DST(0, 1)                         = AVG3(B, C, D);
+  DST(2, 0) = DST(1, 1) = DST(0, 2)             = AVG3(C, D, E);
+  DST(3, 0) = DST(2, 1) = DST(1, 2) = DST(0, 3) = AVG3(D, E, F);
+  DST(3, 1) = DST(2, 2) = DST(1, 3)             = AVG3(E, F, G);
+  DST(3, 2) = DST(2, 3)                         = AVG3(F, G, H);
+  DST(3, 3)                                     = AVG3(G, H, H);
+}
+
+static void VR4(uint8_t *dst) {   // Vertical-Right
+  const int I = dst[-1 + 0 * BPS];
+  const int J = dst[-1 + 1 * BPS];
+  const int K = dst[-1 + 2 * BPS];
+  const int X = dst[-1 - BPS];
+  const int A = dst[0 - BPS];
+  const int B = dst[1 - BPS];
+  const int C = dst[2 - BPS];
+  const int D = dst[3 - BPS];
+  DST(0, 0) = DST(1, 2) = AVG2(X, A);
+  DST(1, 0) = DST(2, 2) = AVG2(A, B);
+  DST(2, 0) = DST(3, 2) = AVG2(B, C);
+  DST(3, 0)             = AVG2(C, D);
+
+  DST(0, 3) =             AVG3(K, J, I);
+  DST(0, 2) =             AVG3(J, I, X);
+  DST(0, 1) = DST(1, 3) = AVG3(I, X, A);
+  DST(1, 1) = DST(2, 3) = AVG3(X, A, B);
+  DST(2, 1) = DST(3, 3) = AVG3(A, B, C);
+  DST(3, 1) =             AVG3(B, C, D);
+}
+
+static void VL4(uint8_t *dst) {   // Vertical-Left
+  const int A = dst[0 - BPS];
+  const int B = dst[1 - BPS];
+  const int C = dst[2 - BPS];
+  const int D = dst[3 - BPS];
+  const int E = dst[4 - BPS];
+  const int F = dst[5 - BPS];
+  const int G = dst[6 - BPS];
+  const int H = dst[7 - BPS];
+  DST(0, 0) =             AVG2(A, B);
+  DST(1, 0) = DST(0, 2) = AVG2(B, C);
+  DST(2, 0) = DST(1, 2) = AVG2(C, D);
+  DST(3, 0) = DST(2, 2) = AVG2(D, E);
+
+  DST(0, 1) =             AVG3(A, B, C);
+  DST(1, 1) = DST(0, 3) = AVG3(B, C, D);
+  DST(2, 1) = DST(1, 3) = AVG3(C, D, E);
+  DST(3, 1) = DST(2, 3) = AVG3(D, E, F);
+              DST(3, 2) = AVG3(E, F, G);
+              DST(3, 3) = AVG3(F, G, H);
+}
+
+static void HU4(uint8_t *dst) {   // Horizontal-Up
+  const int I = dst[-1 + 0 * BPS];
+  const int J = dst[-1 + 1 * BPS];
+  const int K = dst[-1 + 2 * BPS];
+  const int L = dst[-1 + 3 * BPS];
+  DST(0, 0) =             AVG2(I, J);
+  DST(2, 0) = DST(0, 1) = AVG2(J, K);
+  DST(2, 1) = DST(0, 2) = AVG2(K, L);
+  DST(1, 0) =             AVG3(I, J, K);
+  DST(3, 0) = DST(1, 1) = AVG3(J, K, L);
+  DST(3, 1) = DST(1, 2) = AVG3(K, L, L);
+  DST(3, 2) = DST(2, 2) =
+    DST(0, 3) = DST(1, 3) = DST(2, 3) = DST(3, 3) = L;
+}
+
+static void HD4(uint8_t *dst) {  // Horizontal-Down
+  const int I = dst[-1 + 0 * BPS];
+  const int J = dst[-1 + 1 * BPS];
+  const int K = dst[-1 + 2 * BPS];
+  const int L = dst[-1 + 3 * BPS];
+  const int X = dst[-1 - BPS];
+  const int A = dst[0 - BPS];
+  const int B = dst[1 - BPS];
+  const int C = dst[2 - BPS];
+
+  DST(0, 0) = DST(2, 1) = AVG2(I, X);
+  DST(0, 1) = DST(2, 2) = AVG2(J, I);
+  DST(0, 2) = DST(2, 3) = AVG2(K, J);
+  DST(0, 3)             = AVG2(L, K);
+
+  DST(3, 0)             = AVG3(A, B, C);
+  DST(2, 0)             = AVG3(X, A, B);
+  DST(1, 0) = DST(3, 1) = AVG3(I, X, A);
+  DST(1, 1) = DST(3, 2) = AVG3(J, I, X);
+  DST(1, 2) = DST(3, 3) = AVG3(K, J, I);
+  DST(1, 3)             = AVG3(L, K, J);
+}
+
+#undef DST
+#undef AVG3
+#undef AVG2
+
+//------------------------------------------------------------------------------
+// Chroma
+
+static void VE8uv(uint8_t *dst) {    // vertical
+  int j;
+  for (j = 0; j < 8; ++j) {
+    memcpy(dst + j * BPS, dst - BPS, 8);
+  }
+}
+
+static void HE8uv(uint8_t *dst) {    // horizontal
+  int j;
+  for (j = 0; j < 8; ++j) {
+    memset(dst, dst[-1], 8);
+    dst += BPS;
+  }
+}
+
+// helper for chroma-DC predictions
+static WEBP_INLINE void Put8x8uv(uint8_t value, uint8_t* dst) {
+  int j;
+  for (j = 0; j < 8; ++j) {
+    memset(dst + j * BPS, value, 8);
+  }
+}
+
+static void DC8uv(uint8_t *dst) {     // DC
+  int dc0 = 8;
+  int i;
+  for (i = 0; i < 8; ++i) {
+    dc0 += dst[i - BPS] + dst[-1 + i * BPS];
+  }
+  Put8x8uv(dc0 >> 4, dst);
+}
+
+static void DC8uvNoLeft(uint8_t *dst) {   // DC with no left samples
+  int dc0 = 4;
+  int i;
+  for (i = 0; i < 8; ++i) {
+    dc0 += dst[i - BPS];
+  }
+  Put8x8uv(dc0 >> 3, dst);
+}
+
+static void DC8uvNoTop(uint8_t *dst) {  // DC with no top samples
+  int dc0 = 4;
+  int i;
+  for (i = 0; i < 8; ++i) {
+    dc0 += dst[-1 + i * BPS];
+  }
+  Put8x8uv(dc0 >> 3, dst);
+}
+
+static void DC8uvNoTopLeft(uint8_t *dst) {    // DC with nothing
+  Put8x8uv(0x80, dst);
+}
+
+//------------------------------------------------------------------------------
+// default C implementations
+
+const VP8PredFunc VP8PredLuma4[NUM_BMODES] = {
+  DC4, TM4, VE4, HE4, RD4, VR4, LD4, VL4, HD4, HU4
+};
+
+const VP8PredFunc VP8PredLuma16[NUM_B_DC_MODES] = {
+  DC16, TM16, VE16, HE16,
+  DC16NoTop, DC16NoLeft, DC16NoTopLeft
+};
+
+const VP8PredFunc VP8PredChroma8[NUM_B_DC_MODES] = {
+  DC8uv, TM8uv, VE8uv, HE8uv,
+  DC8uvNoTop, DC8uvNoLeft, DC8uvNoTopLeft
+};
+
+//------------------------------------------------------------------------------
+// Edge filtering functions
+
+// 4 pixels in, 2 pixels out
+static WEBP_INLINE void do_filter2(uint8_t* p, int step) {
+  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
+  const int a = 3 * (q0 - p0) + VP8ksclip1[p1 - q1];  // in [-893,892]
+  const int a1 = VP8ksclip2[(a + 4) >> 3];            // in [-16,15]
+  const int a2 = VP8ksclip2[(a + 3) >> 3];
+  p[-step] = VP8kclip1[p0 + a2];
+  p[    0] = VP8kclip1[q0 - a1];
+}
+
+// 4 pixels in, 4 pixels out
+static WEBP_INLINE void do_filter4(uint8_t* p, int step) {
+  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
+  const int a = 3 * (q0 - p0);
+  const int a1 = VP8ksclip2[(a + 4) >> 3];
+  const int a2 = VP8ksclip2[(a + 3) >> 3];
+  const int a3 = (a1 + 1) >> 1;
+  p[-2*step] = VP8kclip1[p1 + a3];
+  p[-  step] = VP8kclip1[p0 + a2];
+  p[      0] = VP8kclip1[q0 - a1];
+  p[   step] = VP8kclip1[q1 - a3];
+}
+
+// 6 pixels in, 6 pixels out
+static WEBP_INLINE void do_filter6(uint8_t* p, int step) {
+  const int p2 = p[-3*step], p1 = p[-2*step], p0 = p[-step];
+  const int q0 = p[0], q1 = p[step], q2 = p[2*step];
+  const int a = VP8ksclip1[3 * (q0 - p0) + VP8ksclip1[p1 - q1]];
+  // a is in [-128,127], a1 in [-27,27], a2 in [-18,18] and a3 in [-9,9]
+  const int a1 = (27 * a + 63) >> 7;  // eq. to ((3 * a + 7) * 9) >> 7
+  const int a2 = (18 * a + 63) >> 7;  // eq. to ((2 * a + 7) * 9) >> 7
+  const int a3 = (9  * a + 63) >> 7;  // eq. to ((1 * a + 7) * 9) >> 7
+  p[-3*step] = VP8kclip1[p2 + a3];
+  p[-2*step] = VP8kclip1[p1 + a2];
+  p[-  step] = VP8kclip1[p0 + a1];
+  p[      0] = VP8kclip1[q0 - a1];
+  p[   step] = VP8kclip1[q1 - a2];
+  p[ 2*step] = VP8kclip1[q2 - a3];
+}
+
+static WEBP_INLINE int hev(const uint8_t* p, int step, int thresh) {
+  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
+  return (VP8kabs0[p1 - p0] > thresh) || (VP8kabs0[q1 - q0] > thresh);
+}
+
+static WEBP_INLINE int needs_filter(const uint8_t* p, int step, int t) {
+  const int p1 = p[-2 * step], p0 = p[-step], q0 = p[0], q1 = p[step];
+  return ((4 * VP8kabs0[p0 - q0] + VP8kabs0[p1 - q1]) <= t);
+}
+
+static WEBP_INLINE int needs_filter2(const uint8_t* p,
+                                     int step, int t, int it) {
+  const int p3 = p[-4 * step], p2 = p[-3 * step], p1 = p[-2 * step];
+  const int p0 = p[-step], q0 = p[0];
+  const int q1 = p[step], q2 = p[2 * step], q3 = p[3 * step];
+  if ((4 * VP8kabs0[p0 - q0] + VP8kabs0[p1 - q1]) > t) return 0;
+  return VP8kabs0[p3 - p2] <= it && VP8kabs0[p2 - p1] <= it &&
+         VP8kabs0[p1 - p0] <= it && VP8kabs0[q3 - q2] <= it &&
+         VP8kabs0[q2 - q1] <= it && VP8kabs0[q1 - q0] <= it;
+}
+
+//------------------------------------------------------------------------------
+// Simple In-loop filtering (Paragraph 15.2)
+
+static void SimpleVFilter16(uint8_t* p, int stride, int thresh) {
+  int i;
+  const int thresh2 = 2 * thresh + 1;
+  for (i = 0; i < 16; ++i) {
+    if (needs_filter(p + i, stride, thresh2)) {
+      do_filter2(p + i, stride);
+    }
+  }
+}
+
+static void SimpleHFilter16(uint8_t* p, int stride, int thresh) {
+  int i;
+  const int thresh2 = 2 * thresh + 1;
+  for (i = 0; i < 16; ++i) {
+    if (needs_filter(p + i * stride, 1, thresh2)) {
+      do_filter2(p + i * stride, 1);
+    }
+  }
+}
+
+static void SimpleVFilter16i(uint8_t* p, int stride, int thresh) {
+  int k;
+  for (k = 3; k > 0; --k) {
+    p += 4 * stride;
+    SimpleVFilter16(p, stride, thresh);
+  }
+}
+
+static void SimpleHFilter16i(uint8_t* p, int stride, int thresh) {
+  int k;
+  for (k = 3; k > 0; --k) {
+    p += 4;
+    SimpleHFilter16(p, stride, thresh);
+  }
+}
+
+//------------------------------------------------------------------------------
+// Complex In-loop filtering (Paragraph 15.3)
+
+static WEBP_INLINE void FilterLoop26(uint8_t* p,
+                                     int hstride, int vstride, int size,
+                                     int thresh, int ithresh, int hev_thresh) {
+  const int thresh2 = 2 * thresh + 1;
+  while (size-- > 0) {
+    if (needs_filter2(p, hstride, thresh2, ithresh)) {
+      if (hev(p, hstride, hev_thresh)) {
+        do_filter2(p, hstride);
+      } else {
+        do_filter6(p, hstride);
+      }
+    }
+    p += vstride;
+  }
+}
+
+static WEBP_INLINE void FilterLoop24(uint8_t* p,
+                                     int hstride, int vstride, int size,
+                                     int thresh, int ithresh, int hev_thresh) {
+  const int thresh2 = 2 * thresh + 1;
+  while (size-- > 0) {
+    if (needs_filter2(p, hstride, thresh2, ithresh)) {
+      if (hev(p, hstride, hev_thresh)) {
+        do_filter2(p, hstride);
+      } else {
+        do_filter4(p, hstride);
+      }
+    }
+    p += vstride;
+  }
+}
+
+// on macroblock edges
+static void VFilter16(uint8_t* p, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  FilterLoop26(p, stride, 1, 16, thresh, ithresh, hev_thresh);
+}
+
+static void HFilter16(uint8_t* p, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  FilterLoop26(p, 1, stride, 16, thresh, ithresh, hev_thresh);
+}
+
+// on three inner edges
+static void VFilter16i(uint8_t* p, int stride,
+                       int thresh, int ithresh, int hev_thresh) {
+  int k;
+  for (k = 3; k > 0; --k) {
+    p += 4 * stride;
+    FilterLoop24(p, stride, 1, 16, thresh, ithresh, hev_thresh);
+  }
+}
+
+static void HFilter16i(uint8_t* p, int stride,
+                       int thresh, int ithresh, int hev_thresh) {
+  int k;
+  for (k = 3; k > 0; --k) {
+    p += 4;
+    FilterLoop24(p, 1, stride, 16, thresh, ithresh, hev_thresh);
+  }
+}
+
+// 8-pixels wide variant, for chroma filtering
+static void VFilter8(uint8_t* u, uint8_t* v, int stride,
+                     int thresh, int ithresh, int hev_thresh) {
+  FilterLoop26(u, stride, 1, 8, thresh, ithresh, hev_thresh);
+  FilterLoop26(v, stride, 1, 8, thresh, ithresh, hev_thresh);
+}
+
+static void HFilter8(uint8_t* u, uint8_t* v, int stride,
+                     int thresh, int ithresh, int hev_thresh) {
+  FilterLoop26(u, 1, stride, 8, thresh, ithresh, hev_thresh);
+  FilterLoop26(v, 1, stride, 8, thresh, ithresh, hev_thresh);
+}
+
+static void VFilter8i(uint8_t* u, uint8_t* v, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  FilterLoop24(u + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);
+  FilterLoop24(v + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);
+}
+
+static void HFilter8i(uint8_t* u, uint8_t* v, int stride,
+                      int thresh, int ithresh, int hev_thresh) {
+  FilterLoop24(u + 4, 1, stride, 8, thresh, ithresh, hev_thresh);
+  FilterLoop24(v + 4, 1, stride, 8, thresh, ithresh, hev_thresh);
+}
+
+//------------------------------------------------------------------------------
+
+VP8DecIdct2 VP8Transform;
+VP8DecIdct VP8TransformAC3;
+VP8DecIdct VP8TransformUV;
+VP8DecIdct VP8TransformDC;
+VP8DecIdct VP8TransformDCUV;
+
+VP8LumaFilterFunc VP8VFilter16;
+VP8LumaFilterFunc VP8HFilter16;
+VP8ChromaFilterFunc VP8VFilter8;
+VP8ChromaFilterFunc VP8HFilter8;
+VP8LumaFilterFunc VP8VFilter16i;
+VP8LumaFilterFunc VP8HFilter16i;
+VP8ChromaFilterFunc VP8VFilter8i;
+VP8ChromaFilterFunc VP8HFilter8i;
+VP8SimpleFilterFunc VP8SimpleVFilter16;
+VP8SimpleFilterFunc VP8SimpleHFilter16;
+VP8SimpleFilterFunc VP8SimpleVFilter16i;
+VP8SimpleFilterFunc VP8SimpleHFilter16i;
+
+extern void VP8DspInitSSE2(void);
+extern void VP8DspInitNEON(void);
+extern void VP8DspInitMIPS32(void);
+
+void VP8DspInit(void) {
+  VP8InitClipTables();
+
+  VP8TransformWHT = TransformWHT;
+  VP8Transform = TransformTwo;
+  VP8TransformUV = TransformUV;
+  VP8TransformDC = TransformDC;
+  VP8TransformDCUV = TransformDCUV;
+  VP8TransformAC3 = TransformAC3;
+
+  VP8VFilter16 = VFilter16;
+  VP8HFilter16 = HFilter16;
+  VP8VFilter8 = VFilter8;
+  VP8HFilter8 = HFilter8;
+  VP8VFilter16i = VFilter16i;
+  VP8HFilter16i = HFilter16i;
+  VP8VFilter8i = VFilter8i;
+  VP8HFilter8i = HFilter8i;
+  VP8SimpleVFilter16 = SimpleVFilter16;
+  VP8SimpleHFilter16 = SimpleHFilter16;
+  VP8SimpleVFilter16i = SimpleVFilter16i;
+  VP8SimpleHFilter16i = SimpleHFilter16i;
+
+  // If defined, use CPUInfo() to overwrite some pointers with faster versions.
+  if (VP8GetCPUInfo != NULL) {
+#if defined(WEBP_USE_SSE2)
+    if (VP8GetCPUInfo(kSSE2)) {
+      VP8DspInitSSE2();
+    }
+#elif defined(WEBP_USE_NEON)
+    if (VP8GetCPUInfo(kNEON)) {
+      VP8DspInitNEON();
+    }
+#elif defined(WEBP_USE_MIPS32)
+    if (VP8GetCPUInfo(kMIPS32)) {
+      VP8DspInitMIPS32();
+    }
+#endif
+  }
+}
+