// 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, default plain-C implementations.

//

// Author: Skal (pascal.massimino@gmail.com)

#include <assert.h>

#include <stddef.h>

#include <string.h>

#include "src/dec/common_dec.h"

#include "src/dec/vp8i_dec.h"

#include "src/dsp/cpu.h"

#include "src/dsp/dsp.h"

#include "src/utils/utils.h"

#include "src/webp/types.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)

#if !WEBP_NEON_OMIT_C_CODE

static void TransformOne_C(const int16_t* WEBP_RESTRICT in,

                           uint8_t* WEBP_RESTRICT 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 = WEBP_TRANSFORM_AC3_MUL2(in[4]) -

                  WEBP_TRANSFORM_AC3_MUL1(in[12]);  // [-3783, 3783]

    const int d = WEBP_TRANSFORM_AC3_MUL1(in[4]) +

                  WEBP_TRANSFORM_AC3_MUL2(in[12]);  // [-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. + (20091 + 35468) / 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 =

        WEBP_TRANSFORM_AC3_MUL2(tmp[4]) - WEBP_TRANSFORM_AC3_MUL1(tmp[12]);

    const int d =

        WEBP_TRANSFORM_AC3_MUL1(tmp[4]) + WEBP_TRANSFORM_AC3_MUL2(tmp[12]);

    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_C(const int16_t* WEBP_RESTRICT in,

                           uint8_t* WEBP_RESTRICT dst) {

  const int a = in[0] + 4;

  const int c4 = WEBP_TRANSFORM_AC3_MUL2(in[4]);

  const int d4 = WEBP_TRANSFORM_AC3_MUL1(in[4]);

  const int c1 = WEBP_TRANSFORM_AC3_MUL2(in[1]);

  const int d1 = WEBP_TRANSFORM_AC3_MUL1(in[1]);

  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 STORE2

static void TransformTwo_C(const int16_t* WEBP_RESTRICT in,

                           uint8_t* WEBP_RESTRICT dst, int do_two) {

  TransformOne_C(in, dst);

  if (do_two) {

    TransformOne_C(in + 16, dst + 4);

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

static void TransformUV_C(const int16_t* WEBP_RESTRICT in,

                          uint8_t* WEBP_RESTRICT dst) {

  VP8Transform(in + 0 * 16, dst, 1);

  VP8Transform(in + 2 * 16, dst + 4 * BPS, 1);

}

#if !WEBP_NEON_OMIT_C_CODE

static void TransformDC_C(const int16_t* WEBP_RESTRICT in,

                          uint8_t* WEBP_RESTRICT 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);

    }

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

static void TransformDCUV_C(const int16_t* WEBP_RESTRICT in,

                            uint8_t* WEBP_RESTRICT 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

#if !WEBP_NEON_OMIT_C_CODE

static void TransformWHT_C(const int16_t* WEBP_RESTRICT in,

                           int16_t* WEBP_RESTRICT 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;

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

VP8WHT VP8TransformWHT;

//------------------------------------------------------------------------------

// Intra predictions

#define DST(x, y) dst[(x) + (y) * BPS]

#if !WEBP_NEON_OMIT_C_CODE

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_C(uint8_t* dst)   { TrueMotion(dst, 4); }

static void TM8uv_C(uint8_t* dst) { TrueMotion(dst, 8); }

static void TM16_C(uint8_t* dst)  { TrueMotion(dst, 16); }

//------------------------------------------------------------------------------

// 16x16

static void VE16_C(uint8_t* dst) {     // vertical

  int j;

  for (j = 0; j < 16; ++j) {

    memcpy(dst + j * BPS, dst - BPS, 16);

  }

}

static void HE16_C(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_C(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_C(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_C(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_C(uint8_t* dst) {  // DC with no top and left samples

  Put16(0x80, dst);

}

#endif  // !WEBP_NEON_OMIT_C_CODE

VP8PredFunc VP8PredLuma16[NUM_B_DC_MODES];

//------------------------------------------------------------------------------

// 4x4

#define AVG3(a, b, c) ((uint8_t)(((a) + 2 * (b) + (c) + 2) >> 2))

#define AVG2(a, b) (((a) + (b) + 1) >> 1)

#if !WEBP_NEON_OMIT_C_CODE

static void VE4_C(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));

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

static void HE4_C(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];

  WebPUint32ToMem(dst + 0 * BPS, 0x01010101U * AVG3(A, B, C));

  WebPUint32ToMem(dst + 1 * BPS, 0x01010101U * AVG3(B, C, D));

  WebPUint32ToMem(dst + 2 * BPS, 0x01010101U * AVG3(C, D, E));

  WebPUint32ToMem(dst + 3 * BPS, 0x01010101U * AVG3(D, E, E));

}

#if !WEBP_NEON_OMIT_C_CODE

static void DC4_C(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_C(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(1, 3) = DST(0, 2)                         = AVG3(I, J, K);

  DST(2, 3) = DST(1, 2) = DST(0, 1)             = AVG3(X, I, J);

  DST(3, 3) = DST(2, 2) = DST(1, 1) = DST(0, 0) = AVG3(A, X, I);

              DST(3, 2) = DST(2, 1) = DST(1, 0) = AVG3(B, A, X);

                          DST(3, 1) = DST(2, 0) = AVG3(C, B, A);

                                      DST(3, 0) = AVG3(D, C, B);

}

static void LD4_C(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);

}

#endif  // !WEBP_NEON_OMIT_C_CODE

static void VR4_C(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_C(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_C(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_C(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

VP8PredFunc VP8PredLuma4[NUM_BMODES];

//------------------------------------------------------------------------------

// Chroma

#if !WEBP_NEON_OMIT_C_CODE

static void VE8uv_C(uint8_t* dst) {    // vertical

  int j;

  for (j = 0; j < 8; ++j) {

    memcpy(dst + j * BPS, dst - BPS, 8);

  }

}

static void HE8uv_C(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_C(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_C(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_C(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_C(uint8_t* dst) {    // DC with nothing

  Put8x8uv(0x80, dst);

}

#endif  // !WEBP_NEON_OMIT_C_CODE

VP8PredFunc VP8PredChroma8[NUM_B_DC_MODES];

//------------------------------------------------------------------------------

// Edge filtering functions

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

// 4 pixels in, 2 pixels out

static WEBP_INLINE void DoFilter2_C(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 DoFilter4_C(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 DoFilter6_C(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);

}

#endif  // !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

#if !WEBP_NEON_OMIT_C_CODE

static WEBP_INLINE int NeedsFilter_C(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);

}

#endif  // !WEBP_NEON_OMIT_C_CODE

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

static WEBP_INLINE int NeedsFilter2_C(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;

}

#endif  // !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

//------------------------------------------------------------------------------

// Simple In-loop filtering (Paragraph 15.2)

#if !WEBP_NEON_OMIT_C_CODE

static void SimpleVFilter16_C(uint8_t* p, int stride, int thresh) {

  int i;

  const int thresh2 = 2 * thresh + 1;

  for (i = 0; i < 16; ++i) {

    if (NeedsFilter_C(p + i, stride, thresh2)) {

      DoFilter2_C(p + i, stride);

    }

  }

}

static void SimpleHFilter16_C(uint8_t* p, int stride, int thresh) {

  int i;

  const int thresh2 = 2 * thresh + 1;

  for (i = 0; i < 16; ++i) {

    if (NeedsFilter_C(p + i * stride, 1, thresh2)) {

      DoFilter2_C(p + i * stride, 1);

    }

  }

}

static void SimpleVFilter16i_C(uint8_t* p, int stride, int thresh) {

  int k;

  for (k = 3; k > 0; --k) {

    p += 4 * stride;

    SimpleVFilter16_C(p, stride, thresh);

  }

}

static void SimpleHFilter16i_C(uint8_t* p, int stride, int thresh) {

  int k;

  for (k = 3; k > 0; --k) {

    p += 4;

    SimpleHFilter16_C(p, stride, thresh);

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

//------------------------------------------------------------------------------

// Complex In-loop filtering (Paragraph 15.3)

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

static WEBP_INLINE void FilterLoop26_C(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 (NeedsFilter2_C(p, hstride, thresh2, ithresh)) {

      if (Hev(p, hstride, hev_thresh)) {

        DoFilter2_C(p, hstride);

      } else {

        DoFilter6_C(p, hstride);

      }

    }

    p += vstride;

  }

}

static WEBP_INLINE void FilterLoop24_C(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 (NeedsFilter2_C(p, hstride, thresh2, ithresh)) {

      if (Hev(p, hstride, hev_thresh)) {

        DoFilter2_C(p, hstride);

      } else {

        DoFilter4_C(p, hstride);

      }

    }

    p += vstride;

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

#if !WEBP_NEON_OMIT_C_CODE

// on macroblock edges

static void VFilter16_C(uint8_t* p, int stride,

                        int thresh, int ithresh, int hev_thresh) {

  FilterLoop26_C(p, stride, 1, 16, thresh, ithresh, hev_thresh);

}

static void HFilter16_C(uint8_t* p, int stride,

                        int thresh, int ithresh, int hev_thresh) {

  FilterLoop26_C(p, 1, stride, 16, thresh, ithresh, hev_thresh);

}

// on three inner edges

static void VFilter16i_C(uint8_t* p, int stride,

                         int thresh, int ithresh, int hev_thresh) {

  int k;

  for (k = 3; k > 0; --k) {

    p += 4 * stride;

    FilterLoop24_C(p, stride, 1, 16, thresh, ithresh, hev_thresh);

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

static void HFilter16i_C(uint8_t* p, int stride,

                         int thresh, int ithresh, int hev_thresh) {

  int k;

  for (k = 3; k > 0; --k) {

    p += 4;

    FilterLoop24_C(p, 1, stride, 16, thresh, ithresh, hev_thresh);

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

#if !WEBP_NEON_OMIT_C_CODE

// 8-pixels wide variant, for chroma filtering

static void VFilter8_C(uint8_t* WEBP_RESTRICT u, uint8_t* WEBP_RESTRICT v,

                       int stride, int thresh, int ithresh, int hev_thresh) {

  FilterLoop26_C(u, stride, 1, 8, thresh, ithresh, hev_thresh);

  FilterLoop26_C(v, stride, 1, 8, thresh, ithresh, hev_thresh);

}

#endif  // !WEBP_NEON_OMIT_C_CODE

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

static void HFilter8_C(uint8_t* WEBP_RESTRICT u, uint8_t* WEBP_RESTRICT v,

                       int stride, int thresh, int ithresh, int hev_thresh) {

  FilterLoop26_C(u, 1, stride, 8, thresh, ithresh, hev_thresh);

  FilterLoop26_C(v, 1, stride, 8, thresh, ithresh, hev_thresh);

}

#endif  // !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

#if !WEBP_NEON_OMIT_C_CODE

static void VFilter8i_C(uint8_t* WEBP_RESTRICT u, uint8_t* WEBP_RESTRICT v,

                        int stride, int thresh, int ithresh, int hev_thresh) {

  FilterLoop24_C(u + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);

  FilterLoop24_C(v + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);

}

#endif  // !WEBP_NEON_OMIT_C_CODE

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

static void HFilter8i_C(uint8_t* WEBP_RESTRICT u, uint8_t* WEBP_RESTRICT v,

                        int stride, int thresh, int ithresh, int hev_thresh) {

  FilterLoop24_C(u + 4, 1, stride, 8, thresh, ithresh, hev_thresh);

  FilterLoop24_C(v + 4, 1, stride, 8, thresh, ithresh, hev_thresh);

}

#endif  // !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

//------------------------------------------------------------------------------

static void DitherCombine8x8_C(const uint8_t* WEBP_RESTRICT dither,

                               uint8_t* WEBP_RESTRICT dst, int dst_stride) {

  int i, j;

  for (j = 0; j < 8; ++j) {

    for (i = 0; i < 8; ++i) {

      const int delta0 = dither[i] - VP8_DITHER_AMP_CENTER;

      const int delta1 =

          (delta0 + VP8_DITHER_DESCALE_ROUNDER) >> VP8_DITHER_DESCALE;

      dst[i] = clip_8b((int)dst[i] + delta1);

    }

    dst += dst_stride;

    dither += 8;

  }

}

//------------------------------------------------------------------------------

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;

void (*VP8DitherCombine8x8)(const uint8_t* WEBP_RESTRICT dither,

                            uint8_t* WEBP_RESTRICT dst, int dst_stride);

extern VP8CPUInfo VP8GetCPUInfo;

extern void VP8DspInitSSE2(void);

extern void VP8DspInitSSE41(void);

extern void VP8DspInitNEON(void);

extern void VP8DspInitMIPS32(void);

extern void VP8DspInitMIPSdspR2(void);

extern void VP8DspInitMSA(void);

WEBP_DSP_INIT_FUNC(VP8DspInit) {

  VP8InitClipTables();

#if !WEBP_NEON_OMIT_C_CODE

  VP8TransformWHT = TransformWHT_C;

  VP8Transform = TransformTwo_C;

  VP8TransformDC = TransformDC_C;

  VP8TransformAC3 = TransformAC3_C;

#endif

  VP8TransformUV = TransformUV_C;

  VP8TransformDCUV = TransformDCUV_C;

#if !WEBP_NEON_OMIT_C_CODE

  VP8VFilter16 = VFilter16_C;

  VP8VFilter16i = VFilter16i_C;

  VP8HFilter16 = HFilter16_C;

  VP8VFilter8 = VFilter8_C;

  VP8VFilter8i = VFilter8i_C;

  VP8SimpleVFilter16 = SimpleVFilter16_C;

  VP8SimpleHFilter16 = SimpleHFilter16_C;

  VP8SimpleVFilter16i = SimpleVFilter16i_C;

  VP8SimpleHFilter16i = SimpleHFilter16i_C;

#endif

#if !WEBP_NEON_OMIT_C_CODE || WEBP_NEON_WORK_AROUND_GCC

  VP8HFilter16i = HFilter16i_C;

  VP8HFilter8 = HFilter8_C;

  VP8HFilter8i = HFilter8i_C;

#endif

#if !WEBP_NEON_OMIT_C_CODE

  VP8PredLuma4[0] = DC4_C;

  VP8PredLuma4[1] = TM4_C;

  VP8PredLuma4[2] = VE4_C;

  VP8PredLuma4[4] = RD4_C;

  VP8PredLuma4[6] = LD4_C;

#endif

  VP8PredLuma4[3] = HE4_C;

  VP8PredLuma4[5] = VR4_C;

  VP8PredLuma4[7] = VL4_C;

  VP8PredLuma4[8] = HD4_C;

  VP8PredLuma4[9] = HU4_C;

#if !WEBP_NEON_OMIT_C_CODE

  VP8PredLuma16[0] = DC16_C;

  VP8PredLuma16[1] = TM16_C;

  VP8PredLuma16[2] = VE16_C;

  VP8PredLuma16[3] = HE16_C;

  VP8PredLuma16[4] = DC16NoTop_C;

  VP8PredLuma16[5] = DC16NoLeft_C;

  VP8PredLuma16[6] = DC16NoTopLeft_C;

  VP8PredChroma8[0] = DC8uv_C;

  VP8PredChroma8[1] = TM8uv_C;

  VP8PredChroma8[2] = VE8uv_C;

  VP8PredChroma8[3] = HE8uv_C;

  VP8PredChroma8[4] = DC8uvNoTop_C;

  VP8PredChroma8[5] = DC8uvNoLeft_C;

  VP8PredChroma8[6] = DC8uvNoTopLeft_C;

#endif

  VP8DitherCombine8x8 = DitherCombine8x8_C;

  // If defined, use CPUInfo() to overwrite some pointers with faster versions.

  if (VP8GetCPUInfo != NULL) {

#if defined(WEBP_HAVE_SSE2)

    if (VP8GetCPUInfo(kSSE2)) {

      VP8DspInitSSE2();

#if defined(WEBP_HAVE_SSE41)

      if (VP8GetCPUInfo(kSSE4_1)) {

        VP8DspInitSSE41();

      }

#endif

    }

#endif

#if defined(WEBP_USE_MIPS32)

    if (VP8GetCPUInfo(kMIPS32)) {

      VP8DspInitMIPS32();

    }

#endif

#if defined(WEBP_USE_MIPS_DSP_R2)

    if (VP8GetCPUInfo(kMIPSdspR2)) {

      VP8DspInitMIPSdspR2();

    }

#endif

#if defined(WEBP_USE_MSA)

    if (VP8GetCPUInfo(kMSA)) {

      VP8DspInitMSA();

    }

#endif

  }

#if defined(WEBP_HAVE_NEON)

  if (WEBP_NEON_OMIT_C_CODE ||

      (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {

    VP8DspInitNEON();

  }

#endif

  assert(VP8TransformWHT != NULL);

  assert(VP8Transform != NULL);