/*
 *  Copyright 2011 The LibYuv Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE 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.
 */

#include "libyuv/row.h"

#include <stdio.h>
#include <string.h>  // For memcpy and memset.

#include "libyuv/basic_types.h"
#include "libyuv/convert_argb.h"  // For kYuvI601Constants

#ifdef __cplusplus
namespace libyuv {
extern "C" {
#endif

// The following ifdef from row_win makes the C code match the row_win code,
// which is 7 bit fixed point.
#if !defined(LIBYUV_DISABLE_X86) && defined(_MSC_VER) && \
    (defined(_M_IX86) || (defined(_M_X64) && !defined(__clang__)))
#define LIBYUV_RGB7 1
#endif

#if defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || \
    defined(_M_IX86)
#define LIBYUV_ARGBTOUV_PAVGB 1
#define LIBYUV_RGBTOU_TRUNCATE 1
#endif

// llvm x86 is poor at ternary operator, so use branchless min/max.

#define USE_BRANCHLESS 1
#if USE_BRANCHLESS
static __inline int32_t clamp0(int32_t v) {
  return -(v >= 0) & v;
}
// TODO(fbarchard): make clamp255 preserve negative values.
static __inline int32_t clamp255(int32_t v) {
  return (-(v >= 255) | v) & 255;
}

static __inline int32_t clamp1023(int32_t v) {
  return (-(v >= 1023) | v) & 1023;
}

static __inline uint32_t Abs(int32_t v) {
  int m = -(v < 0);
  return (v + m) ^ m;
}
#else   // USE_BRANCHLESS
static __inline int32_t clamp0(int32_t v) {
  return (v < 0) ? 0 : v;
}

static __inline int32_t clamp255(int32_t v) {
  return (v > 255) ? 255 : v;
}

static __inline int32_t clamp1023(int32_t v) {
  return (v > 1023) ? 1023 : v;
}

static __inline uint32_t Abs(int32_t v) {
  return (v < 0) ? -v : v;
}
#endif  // USE_BRANCHLESS
static __inline uint32_t Clamp(int32_t val) {
  int v = clamp0(val);
  return (uint32_t)(clamp255(v));
}

static __inline uint32_t Clamp10(int32_t val) {
  int v = clamp0(val);
  return (uint32_t)(clamp1023(v));
}

// Little Endian
#if defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || \
    defined(_M_IX86) || defined(__arm__) || defined(_M_ARM) ||     \
    (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
#define WRITEWORD(p, v) *(uint32_t*)(p) = v
#else
static inline void WRITEWORD(uint8_t* p, uint32_t v) {
  p[0] = (uint8_t)(v & 255);
  p[1] = (uint8_t)((v >> 8) & 255);
  p[2] = (uint8_t)((v >> 16) & 255);
  p[3] = (uint8_t)((v >> 24) & 255);
}
#endif

void RGB24ToARGBRow_C(const uint8_t* src_rgb24, uint8_t* dst_argb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_rgb24[0];
    uint8_t g = src_rgb24[1];
    uint8_t r = src_rgb24[2];
    dst_argb[0] = b;
    dst_argb[1] = g;
    dst_argb[2] = r;
    dst_argb[3] = 255u;
    dst_argb += 4;
    src_rgb24 += 3;
  }
}

void RAWToARGBRow_C(const uint8_t* src_raw, uint8_t* dst_argb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t r = src_raw[0];
    uint8_t g = src_raw[1];
    uint8_t b = src_raw[2];
    dst_argb[0] = b;
    dst_argb[1] = g;
    dst_argb[2] = r;
    dst_argb[3] = 255u;
    dst_argb += 4;
    src_raw += 3;
  }
}

void RAWToRGBARow_C(const uint8_t* src_raw, uint8_t* dst_rgba, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t r = src_raw[0];
    uint8_t g = src_raw[1];
    uint8_t b = src_raw[2];
    dst_rgba[0] = 255u;
    dst_rgba[1] = b;
    dst_rgba[2] = g;
    dst_rgba[3] = r;
    dst_rgba += 4;
    src_raw += 3;
  }
}

void RAWToRGB24Row_C(const uint8_t* src_raw, uint8_t* dst_rgb24, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t r = src_raw[0];
    uint8_t g = src_raw[1];
    uint8_t b = src_raw[2];
    dst_rgb24[0] = b;
    dst_rgb24[1] = g;
    dst_rgb24[2] = r;
    dst_rgb24 += 3;
    src_raw += 3;
  }
}

void RGB565ToARGBRow_C(const uint8_t* src_rgb565,
                       uint8_t* dst_argb,
                       int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_rgb565[0] & 0x1f;
    uint8_t g = (src_rgb565[0] >> 5) | ((src_rgb565[1] & 0x07) << 3);
    uint8_t r = src_rgb565[1] >> 3;
    dst_argb[0] = (b << 3) | (b >> 2);
    dst_argb[1] = (g << 2) | (g >> 4);
    dst_argb[2] = (r << 3) | (r >> 2);
    dst_argb[3] = 255u;
    dst_argb += 4;
    src_rgb565 += 2;
  }
}

void ARGB1555ToARGBRow_C(const uint8_t* src_argb1555,
                         uint8_t* dst_argb,
                         int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_argb1555[0] & 0x1f;
    uint8_t g = (src_argb1555[0] >> 5) | ((src_argb1555[1] & 0x03) << 3);
    uint8_t r = (src_argb1555[1] & 0x7c) >> 2;
    uint8_t a = src_argb1555[1] >> 7;
    dst_argb[0] = (b << 3) | (b >> 2);
    dst_argb[1] = (g << 3) | (g >> 2);
    dst_argb[2] = (r << 3) | (r >> 2);
    dst_argb[3] = -a;
    dst_argb += 4;
    src_argb1555 += 2;
  }
}

void ARGB4444ToARGBRow_C(const uint8_t* src_argb4444,
                         uint8_t* dst_argb,
                         int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_argb4444[0] & 0x0f;
    uint8_t g = src_argb4444[0] >> 4;
    uint8_t r = src_argb4444[1] & 0x0f;
    uint8_t a = src_argb4444[1] >> 4;
    dst_argb[0] = (b << 4) | b;
    dst_argb[1] = (g << 4) | g;
    dst_argb[2] = (r << 4) | r;
    dst_argb[3] = (a << 4) | a;
    dst_argb += 4;
    src_argb4444 += 2;
  }
}

void AR30ToARGBRow_C(const uint8_t* src_ar30, uint8_t* dst_argb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint32_t ar30;
    memcpy(&ar30, src_ar30, sizeof ar30);
    uint32_t b = (ar30 >> 2) & 0xff;
    uint32_t g = (ar30 >> 12) & 0xff;
    uint32_t r = (ar30 >> 22) & 0xff;
    uint32_t a = (ar30 >> 30) * 0x55;  // Replicate 2 bits to 8 bits.
    *(uint32_t*)(dst_argb) = b | (g << 8) | (r << 16) | (a << 24);
    dst_argb += 4;
    src_ar30 += 4;
  }
}

void AR30ToABGRRow_C(const uint8_t* src_ar30, uint8_t* dst_abgr, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint32_t ar30;
    memcpy(&ar30, src_ar30, sizeof ar30);
    uint32_t b = (ar30 >> 2) & 0xff;
    uint32_t g = (ar30 >> 12) & 0xff;
    uint32_t r = (ar30 >> 22) & 0xff;
    uint32_t a = (ar30 >> 30) * 0x55;  // Replicate 2 bits to 8 bits.
    *(uint32_t*)(dst_abgr) = r | (g << 8) | (b << 16) | (a << 24);
    dst_abgr += 4;
    src_ar30 += 4;
  }
}

void AR30ToAB30Row_C(const uint8_t* src_ar30, uint8_t* dst_ab30, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint32_t ar30;
    memcpy(&ar30, src_ar30, sizeof ar30);
    uint32_t b = ar30 & 0x3ff;
    uint32_t ga = ar30 & 0xc00ffc00;
    uint32_t r = (ar30 >> 20) & 0x3ff;
    *(uint32_t*)(dst_ab30) = r | ga | (b << 20);
    dst_ab30 += 4;
    src_ar30 += 4;
  }
}

void ARGBToRGB24Row_C(const uint8_t* src_argb, uint8_t* dst_rgb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_argb[0];
    uint8_t g = src_argb[1];
    uint8_t r = src_argb[2];
    dst_rgb[0] = b;
    dst_rgb[1] = g;
    dst_rgb[2] = r;
    dst_rgb += 3;
    src_argb += 4;
  }
}

void ARGBToRAWRow_C(const uint8_t* src_argb, uint8_t* dst_rgb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_argb[0];
    uint8_t g = src_argb[1];
    uint8_t r = src_argb[2];
    dst_rgb[0] = r;
    dst_rgb[1] = g;
    dst_rgb[2] = b;
    dst_rgb += 3;
    src_argb += 4;
  }
}

void ARGBToRGB565Row_C(const uint8_t* src_argb, uint8_t* dst_rgb, int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t b0 = src_argb[0] >> 3;
    uint8_t g0 = src_argb[1] >> 2;
    uint8_t r0 = src_argb[2] >> 3;
    uint8_t b1 = src_argb[4] >> 3;
    uint8_t g1 = src_argb[5] >> 2;
    uint8_t r1 = src_argb[6] >> 3;
    WRITEWORD(dst_rgb, b0 | (g0 << 5) | (r0 << 11) | (b1 << 16) | (g1 << 21) |
                           (r1 << 27));
    dst_rgb += 4;
    src_argb += 8;
  }
  if (width & 1) {
    uint8_t b0 = src_argb[0] >> 3;
    uint8_t g0 = src_argb[1] >> 2;
    uint8_t r0 = src_argb[2] >> 3;
    *(uint16_t*)(dst_rgb) = b0 | (g0 << 5) | (r0 << 11);
  }
}

// dither4 is a row of 4 values from 4x4 dither matrix.
// The 4x4 matrix contains values to increase RGB.  When converting to
// fewer bits (565) this provides an ordered dither.
// The order in the 4x4 matrix in first byte is upper left.
// The 4 values are passed as an int, then referenced as an array, so
// endian will not affect order of the original matrix.  But the dither4
// will containing the first pixel in the lower byte for little endian
// or the upper byte for big endian.
void ARGBToRGB565DitherRow_C(const uint8_t* src_argb,
                             uint8_t* dst_rgb,
                             const uint32_t dither4,
                             int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    int dither0 = ((const unsigned char*)(&dither4))[x & 3];
    int dither1 = ((const unsigned char*)(&dither4))[(x + 1) & 3];
    uint8_t b0 = clamp255(src_argb[0] + dither0) >> 3;
    uint8_t g0 = clamp255(src_argb[1] + dither0) >> 2;
    uint8_t r0 = clamp255(src_argb[2] + dither0) >> 3;
    uint8_t b1 = clamp255(src_argb[4] + dither1) >> 3;
    uint8_t g1 = clamp255(src_argb[5] + dither1) >> 2;
    uint8_t r1 = clamp255(src_argb[6] + dither1) >> 3;
    WRITEWORD(dst_rgb, b0 | (g0 << 5) | (r0 << 11) | (b1 << 16) | (g1 << 21) |
                           (r1 << 27));
    dst_rgb += 4;
    src_argb += 8;
  }
  if (width & 1) {
    int dither0 = ((const unsigned char*)(&dither4))[(width - 1) & 3];
    uint8_t b0 = clamp255(src_argb[0] + dither0) >> 3;
    uint8_t g0 = clamp255(src_argb[1] + dither0) >> 2;
    uint8_t r0 = clamp255(src_argb[2] + dither0) >> 3;
    *(uint16_t*)(dst_rgb) = b0 | (g0 << 5) | (r0 << 11);
  }
}

void ARGBToARGB1555Row_C(const uint8_t* src_argb, uint8_t* dst_rgb, int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t b0 = src_argb[0] >> 3;
    uint8_t g0 = src_argb[1] >> 3;
    uint8_t r0 = src_argb[2] >> 3;
    uint8_t a0 = src_argb[3] >> 7;
    uint8_t b1 = src_argb[4] >> 3;
    uint8_t g1 = src_argb[5] >> 3;
    uint8_t r1 = src_argb[6] >> 3;
    uint8_t a1 = src_argb[7] >> 7;
    *(uint32_t*)(dst_rgb) = b0 | (g0 << 5) | (r0 << 10) | (a0 << 15) |
                            (b1 << 16) | (g1 << 21) | (r1 << 26) | (a1 << 31);
    dst_rgb += 4;
    src_argb += 8;
  }
  if (width & 1) {
    uint8_t b0 = src_argb[0] >> 3;
    uint8_t g0 = src_argb[1] >> 3;
    uint8_t r0 = src_argb[2] >> 3;
    uint8_t a0 = src_argb[3] >> 7;
    *(uint16_t*)(dst_rgb) = b0 | (g0 << 5) | (r0 << 10) | (a0 << 15);
  }
}

void ARGBToARGB4444Row_C(const uint8_t* src_argb, uint8_t* dst_rgb, int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t b0 = src_argb[0] >> 4;
    uint8_t g0 = src_argb[1] >> 4;
    uint8_t r0 = src_argb[2] >> 4;
    uint8_t a0 = src_argb[3] >> 4;
    uint8_t b1 = src_argb[4] >> 4;
    uint8_t g1 = src_argb[5] >> 4;
    uint8_t r1 = src_argb[6] >> 4;
    uint8_t a1 = src_argb[7] >> 4;
    *(uint32_t*)(dst_rgb) = b0 | (g0 << 4) | (r0 << 8) | (a0 << 12) |
                            (b1 << 16) | (g1 << 20) | (r1 << 24) | (a1 << 28);
    dst_rgb += 4;
    src_argb += 8;
  }
  if (width & 1) {
    uint8_t b0 = src_argb[0] >> 4;
    uint8_t g0 = src_argb[1] >> 4;
    uint8_t r0 = src_argb[2] >> 4;
    uint8_t a0 = src_argb[3] >> 4;
    *(uint16_t*)(dst_rgb) = b0 | (g0 << 4) | (r0 << 8) | (a0 << 12);
  }
}

void ABGRToAR30Row_C(const uint8_t* src_abgr, uint8_t* dst_ar30, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint32_t b0 = (src_abgr[0] >> 6) | ((uint32_t)(src_abgr[0]) << 2);
    uint32_t g0 = (src_abgr[1] >> 6) | ((uint32_t)(src_abgr[1]) << 2);
    uint32_t r0 = (src_abgr[2] >> 6) | ((uint32_t)(src_abgr[2]) << 2);
    uint32_t a0 = (src_abgr[3] >> 6);
    *(uint32_t*)(dst_ar30) = r0 | (g0 << 10) | (b0 << 20) | (a0 << 30);
    dst_ar30 += 4;
    src_abgr += 4;
  }
}

void ARGBToAR30Row_C(const uint8_t* src_argb, uint8_t* dst_ar30, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint32_t b0 = (src_argb[0] >> 6) | ((uint32_t)(src_argb[0]) << 2);
    uint32_t g0 = (src_argb[1] >> 6) | ((uint32_t)(src_argb[1]) << 2);
    uint32_t r0 = (src_argb[2] >> 6) | ((uint32_t)(src_argb[2]) << 2);
    uint32_t a0 = (src_argb[3] >> 6);
    *(uint32_t*)(dst_ar30) = b0 | (g0 << 10) | (r0 << 20) | (a0 << 30);
    dst_ar30 += 4;
    src_argb += 4;
  }
}

#ifdef LIBYUV_RGB7
// Old 7 bit math for compatibility on unsupported platforms.
static __inline int RGBToY(uint8_t r, uint8_t g, uint8_t b) {
  return ((33 * r + 65 * g + 13 * b) >> 7) + 16;
}
#else
// 8 bit
// Intel SSE/AVX uses the following equivalent formula
// 0x7e80 = (66 + 129 + 25) * -128 + 0x1000 (for +16) and 0x0080 for round.
//  return (66 * ((int)r - 128) + 129 * ((int)g - 128) + 25 * ((int)b - 128) +
//  0x7e80) >> 8;

static __inline int RGBToY(uint8_t r, uint8_t g, uint8_t b) {
  return (66 * r + 129 * g + 25 * b + 0x1080) >> 8;
}
#endif

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

#ifdef LIBYUV_RGBTOU_TRUNCATE
static __inline int RGBToU(uint8_t r, uint8_t g, uint8_t b) {
  return (112 * b - 74 * g - 38 * r + 0x8000) >> 8;
}
static __inline int RGBToV(uint8_t r, uint8_t g, uint8_t b) {
  return (112 * r - 94 * g - 18 * b + 0x8000) >> 8;
}
#else
// TODO(fbarchard): Add rounding to SIMD and use this
static __inline int RGBToU(uint8_t r, uint8_t g, uint8_t b) {
  return (112 * b - 74 * g - 38 * r + 0x8080) >> 8;
}
static __inline int RGBToV(uint8_t r, uint8_t g, uint8_t b) {
  return (112 * r - 94 * g - 18 * b + 0x8080) >> 8;
}
#endif

#if !defined(LIBYUV_ARGBTOUV_PAVGB)
static __inline int RGB2xToU(uint16_t r, uint16_t g, uint16_t b) {
  return ((112 / 2) * b - (74 / 2) * g - (38 / 2) * r + 0x8080) >> 8;
}
static __inline int RGB2xToV(uint16_t r, uint16_t g, uint16_t b) {
  return ((112 / 2) * r - (94 / 2) * g - (18 / 2) * b + 0x8080) >> 8;
}
#endif

// ARGBToY_C and ARGBToUV_C
// Intel version mimic SSE/AVX which does 2 pavgb
#if LIBYUV_ARGBTOUV_PAVGB

#define MAKEROWY(NAME, R, G, B, BPP)                                         \
  void NAME##ToYRow_C(const uint8_t* src_argb0, uint8_t* dst_y, int width) { \
    int x;                                                                   \
    for (x = 0; x < width; ++x) {                                            \
      dst_y[0] = RGBToY(src_argb0[R], src_argb0[G], src_argb0[B]);           \
      src_argb0 += BPP;                                                      \
      dst_y += 1;                                                            \
    }                                                                        \
  }                                                                          \
  void NAME##ToUVRow_C(const uint8_t* src_rgb0, int src_stride_rgb,          \
                       uint8_t* dst_u, uint8_t* dst_v, int width) {          \
    const uint8_t* src_rgb1 = src_rgb0 + src_stride_rgb;                     \
    int x;                                                                   \
    for (x = 0; x < width - 1; x += 2) {                                     \
      uint8_t ab = AVGB(AVGB(src_rgb0[B], src_rgb1[B]),                      \
                        AVGB(src_rgb0[B + BPP], src_rgb1[B + BPP]));         \
      uint8_t ag = AVGB(AVGB(src_rgb0[G], src_rgb1[G]),                      \
                        AVGB(src_rgb0[G + BPP], src_rgb1[G + BPP]));         \
      uint8_t ar = AVGB(AVGB(src_rgb0[R], src_rgb1[R]),                      \
                        AVGB(src_rgb0[R + BPP], src_rgb1[R + BPP]));         \
      dst_u[0] = RGBToU(ar, ag, ab);                                         \
      dst_v[0] = RGBToV(ar, ag, ab);                                         \
      src_rgb0 += BPP * 2;                                                   \
      src_rgb1 += BPP * 2;                                                   \
      dst_u += 1;                                                            \
      dst_v += 1;                                                            \
    }                                                                        \
    if (width & 1) {                                                         \
      uint8_t ab = AVGB(src_rgb0[B], src_rgb1[B]);                           \
      uint8_t ag = AVGB(src_rgb0[G], src_rgb1[G]);                           \
      uint8_t ar = AVGB(src_rgb0[R], src_rgb1[R]);                           \
      dst_u[0] = RGBToU(ar, ag, ab);                                         \
      dst_v[0] = RGBToV(ar, ag, ab);                                         \
    }                                                                        \
  }
#else
// ARM version does sum / 2 then multiply by 2x smaller coefficients
#define MAKEROWY(NAME, R, G, B, BPP)                                         \
  void NAME##ToYRow_C(const uint8_t* src_argb0, uint8_t* dst_y, int width) { \
    int x;                                                                   \
    for (x = 0; x < width; ++x) {                                            \
      dst_y[0] = RGBToY(src_argb0[R], src_argb0[G], src_argb0[B]);           \
      src_argb0 += BPP;                                                      \
      dst_y += 1;                                                            \
    }                                                                        \
  }                                                                          \
  void NAME##ToUVRow_C(const uint8_t* src_rgb0, int src_stride_rgb,          \
                       uint8_t* dst_u, uint8_t* dst_v, int width) {          \
    const uint8_t* src_rgb1 = src_rgb0 + src_stride_rgb;                     \
    int x;                                                                   \
    for (x = 0; x < width - 1; x += 2) {                                     \
      uint16_t ab = (src_rgb0[B] + src_rgb0[B + BPP] + src_rgb1[B] +         \
                     src_rgb1[B + BPP] + 1) >>                               \
                    1;                                                       \
      uint16_t ag = (src_rgb0[G] + src_rgb0[G + BPP] + src_rgb1[G] +         \
                     src_rgb1[G + BPP] + 1) >>                               \
                    1;                                                       \
      uint16_t ar = (src_rgb0[R] + src_rgb0[R + BPP] + src_rgb1[R] +         \
                     src_rgb1[R + BPP] + 1) >>                               \
                    1;                                                       \
      dst_u[0] = RGB2xToU(ar, ag, ab);                                       \
      dst_v[0] = RGB2xToV(ar, ag, ab);                                       \
      src_rgb0 += BPP * 2;                                                   \
      src_rgb1 += BPP * 2;                                                   \
      dst_u += 1;                                                            \
      dst_v += 1;                                                            \
    }                                                                        \
    if (width & 1) {                                                         \
      uint16_t ab = src_rgb0[B] + src_rgb1[B];                               \
      uint16_t ag = src_rgb0[G] + src_rgb1[G];                               \
      uint16_t ar = src_rgb0[R] + src_rgb1[R];                               \
      dst_u[0] = RGB2xToU(ar, ag, ab);                                       \
      dst_v[0] = RGB2xToV(ar, ag, ab);                                       \
    }                                                                        \
  }
#endif

MAKEROWY(ARGB, 2, 1, 0, 4)
MAKEROWY(BGRA, 1, 2, 3, 4)
MAKEROWY(ABGR, 0, 1, 2, 4)
MAKEROWY(RGBA, 3, 2, 1, 4)
MAKEROWY(RGB24, 2, 1, 0, 3)
MAKEROWY(RAW, 0, 1, 2, 3)
#undef MAKEROWY

// JPeg uses a variation on BT.601-1 full range
// y =  0.29900 * r + 0.58700 * g + 0.11400 * b
// u = -0.16874 * r - 0.33126 * g + 0.50000 * b  + center
// v =  0.50000 * r - 0.41869 * g - 0.08131 * b  + center
// BT.601 Mpeg range uses:
// b 0.1016 * 255 = 25.908 = 25
// g 0.5078 * 255 = 129.489 = 129
// r 0.2578 * 255 = 65.739 = 66
// JPeg 7 bit Y (deprecated)
// b 0.11400 * 128 = 14.592 = 15
// g 0.58700 * 128 = 75.136 = 75
// r 0.29900 * 128 = 38.272 = 38
// JPeg 8 bit Y:
// b 0.11400 * 256 = 29.184 = 29
// g 0.58700 * 256 = 150.272 = 150
// r 0.29900 * 256 = 76.544 = 77
// JPeg 8 bit U:
// b  0.50000 * 255 = 127.5 = 127
// g -0.33126 * 255 = -84.4713 = -84
// r -0.16874 * 255 = -43.0287 = -43
// JPeg 8 bit V:
// b -0.08131 * 255 = -20.73405 = -20
// g -0.41869 * 255 = -106.76595 = -107
// r  0.50000 * 255 = 127.5 = 127

#ifdef LIBYUV_RGB7
// Old 7 bit math for compatibility on unsupported platforms.
static __inline int RGBToYJ(uint8_t r, uint8_t g, uint8_t b) {
  return (38 * r + 75 * g + 15 * b + 64) >> 7;
}
#else
// 8 bit
static __inline int RGBToYJ(uint8_t r, uint8_t g, uint8_t b) {
  return (77 * r + 150 * g + 29 * b + 128) >> 8;
}
#endif

#if defined(LIBYUV_ARGBTOUV_PAVGB)
static __inline int RGBToUJ(uint8_t r, uint8_t g, uint8_t b) {
  return (127 * b - 84 * g - 43 * r + 0x8080) >> 8;
}
static __inline int RGBToVJ(uint8_t r, uint8_t g, uint8_t b) {
  return (127 * r - 107 * g - 20 * b + 0x8080) >> 8;
}
#else
static __inline int RGB2xToUJ(uint16_t r, uint16_t g, uint16_t b) {
  return ((127 / 2) * b - (84 / 2) * g - (43 / 2) * r + 0x8080) >> 8;
}
static __inline int RGB2xToVJ(uint16_t r, uint16_t g, uint16_t b) {
  return ((127 / 2) * r - (107 / 2) * g - (20 / 2) * b + 0x8080) >> 8;
}
#endif

// ARGBToYJ_C and ARGBToUVJ_C
// Intel version mimic SSE/AVX which does 2 pavgb
#if LIBYUV_ARGBTOUV_PAVGB
#define MAKEROWYJ(NAME, R, G, B, BPP)                                         \
  void NAME##ToYJRow_C(const uint8_t* src_argb0, uint8_t* dst_y, int width) { \
    int x;                                                                    \
    for (x = 0; x < width; ++x) {                                             \
      dst_y[0] = RGBToYJ(src_argb0[R], src_argb0[G], src_argb0[B]);           \
      src_argb0 += BPP;                                                       \
      dst_y += 1;                                                             \
    }                                                                         \
  }                                                                           \
  void NAME##ToUVJRow_C(const uint8_t* src_rgb0, int src_stride_rgb,          \
                        uint8_t* dst_u, uint8_t* dst_v, int width) {          \
    const uint8_t* src_rgb1 = src_rgb0 + src_stride_rgb;                      \
    int x;                                                                    \
    for (x = 0; x < width - 1; x += 2) {                                      \
      uint8_t ab = AVGB(AVGB(src_rgb0[B], src_rgb1[B]),                       \
                        AVGB(src_rgb0[B + BPP], src_rgb1[B + BPP]));          \
      uint8_t ag = AVGB(AVGB(src_rgb0[G], src_rgb1[G]),                       \
                        AVGB(src_rgb0[G + BPP], src_rgb1[G + BPP]));          \
      uint8_t ar = AVGB(AVGB(src_rgb0[R], src_rgb1[R]),                       \
                        AVGB(src_rgb0[R + BPP], src_rgb1[R + BPP]));          \
      dst_u[0] = RGBToUJ(ar, ag, ab);                                         \
      dst_v[0] = RGBToVJ(ar, ag, ab);                                         \
      src_rgb0 += BPP * 2;                                                    \
      src_rgb1 += BPP * 2;                                                    \
      dst_u += 1;                                                             \
      dst_v += 1;                                                             \
    }                                                                         \
    if (width & 1) {                                                          \
      uint8_t ab = AVGB(src_rgb0[B], src_rgb1[B]);                            \
      uint8_t ag = AVGB(src_rgb0[G], src_rgb1[G]);                            \
      uint8_t ar = AVGB(src_rgb0[R], src_rgb1[R]);                            \
      dst_u[0] = RGBToUJ(ar, ag, ab);                                         \
      dst_v[0] = RGBToVJ(ar, ag, ab);                                         \
    }                                                                         \
  }
#else
// ARM version does sum / 2 then multiply by 2x smaller coefficients
#define MAKEROWYJ(NAME, R, G, B, BPP)                                         \
  void NAME##ToYJRow_C(const uint8_t* src_argb0, uint8_t* dst_y, int width) { \
    int x;                                                                    \
    for (x = 0; x < width; ++x) {                                             \
      dst_y[0] = RGBToYJ(src_argb0[R], src_argb0[G], src_argb0[B]);           \
      src_argb0 += BPP;                                                       \
      dst_y += 1;                                                             \
    }                                                                         \
  }                                                                           \
  void NAME##ToUVJRow_C(const uint8_t* src_rgb0, int src_stride_rgb,          \
                        uint8_t* dst_u, uint8_t* dst_v, int width) {          \
    const uint8_t* src_rgb1 = src_rgb0 + src_stride_rgb;                      \
    int x;                                                                    \
    for (x = 0; x < width - 1; x += 2) {                                      \
      uint16_t ab = (src_rgb0[B] + src_rgb0[B + BPP] + src_rgb1[B] +          \
                     src_rgb1[B + BPP] + 1) >>                                \
                    1;                                                        \
      uint16_t ag = (src_rgb0[G] + src_rgb0[G + BPP] + src_rgb1[G] +          \
                     src_rgb1[G + BPP] + 1) >>                                \
                    1;                                                        \
      uint16_t ar = (src_rgb0[R] + src_rgb0[R + BPP] + src_rgb1[R] +          \
                     src_rgb1[R + BPP] + 1) >>                                \
                    1;                                                        \
      dst_u[0] = RGB2xToUJ(ar, ag, ab);                                       \
      dst_v[0] = RGB2xToVJ(ar, ag, ab);                                       \
      src_rgb0 += BPP * 2;                                                    \
      src_rgb1 += BPP * 2;                                                    \
      dst_u += 1;                                                             \
      dst_v += 1;                                                             \
    }                                                                         \
    if (width & 1) {                                                          \
      uint16_t ab = (src_rgb0[B] + src_rgb1[B]);                              \
      uint16_t ag = (src_rgb0[G] + src_rgb1[G]);                              \
      uint16_t ar = (src_rgb0[R] + src_rgb1[R]);                              \
      dst_u[0] = RGB2xToUJ(ar, ag, ab);                                       \
      dst_v[0] = RGB2xToVJ(ar, ag, ab);                                       \
    }                                                                         \
  }

#endif

MAKEROWYJ(ARGB, 2, 1, 0, 4)
MAKEROWYJ(RGBA, 3, 2, 1, 4)
MAKEROWYJ(RGB24, 2, 1, 0, 3)
MAKEROWYJ(RAW, 0, 1, 2, 3)
#undef MAKEROWYJ

void RGB565ToYRow_C(const uint8_t* src_rgb565, uint8_t* dst_y, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_rgb565[0] & 0x1f;
    uint8_t g = (src_rgb565[0] >> 5) | ((src_rgb565[1] & 0x07) << 3);
    uint8_t r = src_rgb565[1] >> 3;
    b = (b << 3) | (b >> 2);
    g = (g << 2) | (g >> 4);
    r = (r << 3) | (r >> 2);
    dst_y[0] = RGBToY(r, g, b);
    src_rgb565 += 2;
    dst_y += 1;
  }
}

void ARGB1555ToYRow_C(const uint8_t* src_argb1555, uint8_t* dst_y, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_argb1555[0] & 0x1f;
    uint8_t g = (src_argb1555[0] >> 5) | ((src_argb1555[1] & 0x03) << 3);
    uint8_t r = (src_argb1555[1] & 0x7c) >> 2;
    b = (b << 3) | (b >> 2);
    g = (g << 3) | (g >> 2);
    r = (r << 3) | (r >> 2);
    dst_y[0] = RGBToY(r, g, b);
    src_argb1555 += 2;
    dst_y += 1;
  }
}

void ARGB4444ToYRow_C(const uint8_t* src_argb4444, uint8_t* dst_y, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_argb4444[0] & 0x0f;
    uint8_t g = src_argb4444[0] >> 4;
    uint8_t r = src_argb4444[1] & 0x0f;
    b = (b << 4) | b;
    g = (g << 4) | g;
    r = (r << 4) | r;
    dst_y[0] = RGBToY(r, g, b);
    src_argb4444 += 2;
    dst_y += 1;
  }
}

void RGB565ToUVRow_C(const uint8_t* src_rgb565,
                     int src_stride_rgb565,
                     uint8_t* dst_u,
                     uint8_t* dst_v,
                     int width) {
  const uint8_t* next_rgb565 = src_rgb565 + src_stride_rgb565;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t b0 = src_rgb565[0] & 0x1f;
    uint8_t g0 = (src_rgb565[0] >> 5) | ((src_rgb565[1] & 0x07) << 3);
    uint8_t r0 = src_rgb565[1] >> 3;
    uint8_t b1 = src_rgb565[2] & 0x1f;
    uint8_t g1 = (src_rgb565[2] >> 5) | ((src_rgb565[3] & 0x07) << 3);
    uint8_t r1 = src_rgb565[3] >> 3;
    uint8_t b2 = next_rgb565[0] & 0x1f;
    uint8_t g2 = (next_rgb565[0] >> 5) | ((next_rgb565[1] & 0x07) << 3);
    uint8_t r2 = next_rgb565[1] >> 3;
    uint8_t b3 = next_rgb565[2] & 0x1f;
    uint8_t g3 = (next_rgb565[2] >> 5) | ((next_rgb565[3] & 0x07) << 3);
    uint8_t r3 = next_rgb565[3] >> 3;

    b0 = (b0 << 3) | (b0 >> 2);
    g0 = (g0 << 2) | (g0 >> 4);
    r0 = (r0 << 3) | (r0 >> 2);
    b1 = (b1 << 3) | (b1 >> 2);
    g1 = (g1 << 2) | (g1 >> 4);
    r1 = (r1 << 3) | (r1 >> 2);
    b2 = (b2 << 3) | (b2 >> 2);
    g2 = (g2 << 2) | (g2 >> 4);
    r2 = (r2 << 3) | (r2 >> 2);
    b3 = (b3 << 3) | (b3 >> 2);
    g3 = (g3 << 2) | (g3 >> 4);
    r3 = (r3 << 3) | (r3 >> 2);

#if LIBYUV_ARGBTOUV_PAVGB
    uint8_t ab = AVGB(AVGB(b0, b2), AVGB(b1, b3));
    uint8_t ag = AVGB(AVGB(g0, g2), AVGB(g1, g3));
    uint8_t ar = AVGB(AVGB(r0, r2), AVGB(r1, r3));
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
#else
    uint16_t b = (b0 + b1 + b2 + b3 + 1) >> 1;
    uint16_t g = (g0 + g1 + g2 + g3 + 1) >> 1;
    uint16_t r = (r0 + r1 + r2 + r3 + 1) >> 1;
    dst_u[0] = RGB2xToU(r, g, b);
    dst_v[0] = RGB2xToV(r, g, b);
#endif

    src_rgb565 += 4;
    next_rgb565 += 4;
    dst_u += 1;
    dst_v += 1;
  }
  if (width & 1) {
    uint8_t b0 = src_rgb565[0] & 0x1f;
    uint8_t g0 = (src_rgb565[0] >> 5) | ((src_rgb565[1] & 0x07) << 3);
    uint8_t r0 = src_rgb565[1] >> 3;
    uint8_t b2 = next_rgb565[0] & 0x1f;
    uint8_t g2 = (next_rgb565[0] >> 5) | ((next_rgb565[1] & 0x07) << 3);
    uint8_t r2 = next_rgb565[1] >> 3;

    b0 = (b0 << 3) | (b0 >> 2);
    g0 = (g0 << 2) | (g0 >> 4);
    r0 = (r0 << 3) | (r0 >> 2);
    b2 = (b2 << 3) | (b2 >> 2);
    g2 = (g2 << 2) | (g2 >> 4);
    r2 = (r2 << 3) | (r2 >> 2);

#if LIBYUV_ARGBTOUV_PAVGB
    uint8_t ab = AVGB(b0, b2);
    uint8_t ag = AVGB(g0, g2);
    uint8_t ar = AVGB(r0, r2);
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
#else
    uint16_t b = b0 + b2;
    uint16_t g = g0 + g2;
    uint16_t r = r0 + r2;
    dst_u[0] = RGB2xToU(r, g, b);
    dst_v[0] = RGB2xToV(r, g, b);
#endif
  }
}

void ARGB1555ToUVRow_C(const uint8_t* src_argb1555,
                       int src_stride_argb1555,
                       uint8_t* dst_u,
                       uint8_t* dst_v,
                       int width) {
  const uint8_t* next_argb1555 = src_argb1555 + src_stride_argb1555;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t b0 = src_argb1555[0] & 0x1f;
    uint8_t g0 = (src_argb1555[0] >> 5) | ((src_argb1555[1] & 0x03) << 3);
    uint8_t r0 = (src_argb1555[1] & 0x7c) >> 2;
    uint8_t b1 = src_argb1555[2] & 0x1f;
    uint8_t g1 = (src_argb1555[2] >> 5) | ((src_argb1555[3] & 0x03) << 3);
    uint8_t r1 = (src_argb1555[3] & 0x7c) >> 2;
    uint8_t b2 = next_argb1555[0] & 0x1f;
    uint8_t g2 = (next_argb1555[0] >> 5) | ((next_argb1555[1] & 0x03) << 3);
    uint8_t r2 = (next_argb1555[1] & 0x7c) >> 2;
    uint8_t b3 = next_argb1555[2] & 0x1f;
    uint8_t g3 = (next_argb1555[2] >> 5) | ((next_argb1555[3] & 0x03) << 3);
    uint8_t r3 = (next_argb1555[3] & 0x7c) >> 2;

    b0 = (b0 << 3) | (b0 >> 2);
    g0 = (g0 << 3) | (g0 >> 2);
    r0 = (r0 << 3) | (r0 >> 2);
    b1 = (b1 << 3) | (b1 >> 2);
    g1 = (g1 << 3) | (g1 >> 2);
    r1 = (r1 << 3) | (r1 >> 2);
    b2 = (b2 << 3) | (b2 >> 2);
    g2 = (g2 << 3) | (g2 >> 2);
    r2 = (r2 << 3) | (r2 >> 2);
    b3 = (b3 << 3) | (b3 >> 2);
    g3 = (g3 << 3) | (g3 >> 2);
    r3 = (r3 << 3) | (r3 >> 2);

#if LIBYUV_ARGBTOUV_PAVGB
    uint8_t ab = AVGB(AVGB(b0, b2), AVGB(b1, b3));
    uint8_t ag = AVGB(AVGB(g0, g2), AVGB(g1, g3));
    uint8_t ar = AVGB(AVGB(r0, r2), AVGB(r1, r3));
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
#else
    uint16_t b = (b0 + b1 + b2 + b3 + 1) >> 1;
    uint16_t g = (g0 + g1 + g2 + g3 + 1) >> 1;
    uint16_t r = (r0 + r1 + r2 + r3 + 1) >> 1;
    dst_u[0] = RGB2xToU(r, g, b);
    dst_v[0] = RGB2xToV(r, g, b);
#endif

    src_argb1555 += 4;
    next_argb1555 += 4;
    dst_u += 1;
    dst_v += 1;
  }
  if (width & 1) {
    uint8_t b0 = src_argb1555[0] & 0x1f;
    uint8_t g0 = (src_argb1555[0] >> 5) | ((src_argb1555[1] & 0x03) << 3);
    uint8_t r0 = (src_argb1555[1] & 0x7c) >> 2;
    uint8_t b2 = next_argb1555[0] & 0x1f;
    uint8_t g2 = (next_argb1555[0] >> 5) | ((next_argb1555[1] & 0x03) << 3);
    uint8_t r2 = next_argb1555[1] >> 3;

    b0 = (b0 << 3) | (b0 >> 2);
    g0 = (g0 << 3) | (g0 >> 2);
    r0 = (r0 << 3) | (r0 >> 2);
    b2 = (b2 << 3) | (b2 >> 2);
    g2 = (g2 << 3) | (g2 >> 2);
    r2 = (r2 << 3) | (r2 >> 2);

#if LIBYUV_ARGBTOUV_PAVGB
    uint8_t ab = AVGB(b0, b2);
    uint8_t ag = AVGB(g0, g2);
    uint8_t ar = AVGB(r0, r2);
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
#else
    uint16_t b = b0 + b2;
    uint16_t g = g0 + g2;
    uint16_t r = r0 + r2;
    dst_u[0] = RGB2xToU(r, g, b);
    dst_v[0] = RGB2xToV(r, g, b);
#endif
  }
}

void ARGB4444ToUVRow_C(const uint8_t* src_argb4444,
                       int src_stride_argb4444,
                       uint8_t* dst_u,
                       uint8_t* dst_v,
                       int width) {
  const uint8_t* next_argb4444 = src_argb4444 + src_stride_argb4444;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t b0 = src_argb4444[0] & 0x0f;
    uint8_t g0 = src_argb4444[0] >> 4;
    uint8_t r0 = src_argb4444[1] & 0x0f;
    uint8_t b1 = src_argb4444[2] & 0x0f;
    uint8_t g1 = src_argb4444[2] >> 4;
    uint8_t r1 = src_argb4444[3] & 0x0f;
    uint8_t b2 = next_argb4444[0] & 0x0f;
    uint8_t g2 = next_argb4444[0] >> 4;
    uint8_t r2 = next_argb4444[1] & 0x0f;
    uint8_t b3 = next_argb4444[2] & 0x0f;
    uint8_t g3 = next_argb4444[2] >> 4;
    uint8_t r3 = next_argb4444[3] & 0x0f;

    b0 = (b0 << 4) | b0;
    g0 = (g0 << 4) | g0;
    r0 = (r0 << 4) | r0;
    b1 = (b1 << 4) | b1;
    g1 = (g1 << 4) | g1;
    r1 = (r1 << 4) | r1;
    b2 = (b2 << 4) | b2;
    g2 = (g2 << 4) | g2;
    r2 = (r2 << 4) | r2;
    b3 = (b3 << 4) | b3;
    g3 = (g3 << 4) | g3;
    r3 = (r3 << 4) | r3;

#if LIBYUV_ARGBTOUV_PAVGB
    uint8_t ab = AVGB(AVGB(b0, b2), AVGB(b1, b3));
    uint8_t ag = AVGB(AVGB(g0, g2), AVGB(g1, g3));
    uint8_t ar = AVGB(AVGB(r0, r2), AVGB(r1, r3));
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
#else
    uint16_t b = (b0 + b1 + b2 + b3 + 1) >> 1;
    uint16_t g = (g0 + g1 + g2 + g3 + 1) >> 1;
    uint16_t r = (r0 + r1 + r2 + r3 + 1) >> 1;
    dst_u[0] = RGB2xToU(r, g, b);
    dst_v[0] = RGB2xToV(r, g, b);
#endif

    src_argb4444 += 4;
    next_argb4444 += 4;
    dst_u += 1;
    dst_v += 1;
  }
  if (width & 1) {
    uint8_t b0 = src_argb4444[0] & 0x0f;
    uint8_t g0 = src_argb4444[0] >> 4;
    uint8_t r0 = src_argb4444[1] & 0x0f;
    uint8_t b2 = next_argb4444[0] & 0x0f;
    uint8_t g2 = next_argb4444[0] >> 4;
    uint8_t r2 = next_argb4444[1] & 0x0f;

    b0 = (b0 << 4) | b0;
    g0 = (g0 << 4) | g0;
    r0 = (r0 << 4) | r0;
    b2 = (b2 << 4) | b2;
    g2 = (g2 << 4) | g2;
    r2 = (r2 << 4) | r2;

#if LIBYUV_ARGBTOUV_PAVGB
    uint8_t ab = AVGB(b0, b2);
    uint8_t ag = AVGB(g0, g2);
    uint8_t ar = AVGB(r0, r2);
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
#else
    uint16_t b = b0 + b2;
    uint16_t g = g0 + g2;
    uint16_t r = r0 + r2;
    dst_u[0] = RGB2xToU(r, g, b);
    dst_v[0] = RGB2xToV(r, g, b);
#endif
  }
}

void ARGBToUV444Row_C(const uint8_t* src_argb,
                      uint8_t* dst_u,
                      uint8_t* dst_v,
                      int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t ab = src_argb[0];
    uint8_t ag = src_argb[1];
    uint8_t ar = src_argb[2];
    dst_u[0] = RGBToU(ar, ag, ab);
    dst_v[0] = RGBToV(ar, ag, ab);
    src_argb += 4;
    dst_u += 1;
    dst_v += 1;
  }
}

void ARGBGrayRow_C(const uint8_t* src_argb, uint8_t* dst_argb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t y = RGBToYJ(src_argb[2], src_argb[1], src_argb[0]);
    dst_argb[2] = dst_argb[1] = dst_argb[0] = y;
    dst_argb[3] = src_argb[3];
    dst_argb += 4;
    src_argb += 4;
  }
}

// Convert a row of image to Sepia tone.
void ARGBSepiaRow_C(uint8_t* dst_argb, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    int b = dst_argb[0];
    int g = dst_argb[1];
    int r = dst_argb[2];
    int sb = (b * 17 + g * 68 + r * 35) >> 7;
    int sg = (b * 22 + g * 88 + r * 45) >> 7;
    int sr = (b * 24 + g * 98 + r * 50) >> 7;
    // b does not over flow. a is preserved from original.
    dst_argb[0] = sb;
    dst_argb[1] = clamp255(sg);
    dst_argb[2] = clamp255(sr);
    dst_argb += 4;
  }
}

// Apply color matrix to a row of image. Matrix is signed.
// TODO(fbarchard): Consider adding rounding (+32).
void ARGBColorMatrixRow_C(const uint8_t* src_argb,
                          uint8_t* dst_argb,
                          const int8_t* matrix_argb,
                          int width) {
  int x;
  for (x = 0; x < width; ++x) {
    int b = src_argb[0];
    int g = src_argb[1];
    int r = src_argb[2];
    int a = src_argb[3];
    int sb = (b * matrix_argb[0] + g * matrix_argb[1] + r * matrix_argb[2] +
              a * matrix_argb[3]) >>
             6;
    int sg = (b * matrix_argb[4] + g * matrix_argb[5] + r * matrix_argb[6] +
              a * matrix_argb[7]) >>
             6;
    int sr = (b * matrix_argb[8] + g * matrix_argb[9] + r * matrix_argb[10] +
              a * matrix_argb[11]) >>
             6;
    int sa = (b * matrix_argb[12] + g * matrix_argb[13] + r * matrix_argb[14] +
              a * matrix_argb[15]) >>
             6;
    dst_argb[0] = Clamp(sb);
    dst_argb[1] = Clamp(sg);
    dst_argb[2] = Clamp(sr);
    dst_argb[3] = Clamp(sa);
    src_argb += 4;
    dst_argb += 4;
  }
}

// Apply color table to a row of image.
void ARGBColorTableRow_C(uint8_t* dst_argb,
                         const uint8_t* table_argb,
                         int width) {
  int x;
  for (x = 0; x < width; ++x) {
    int b = dst_argb[0];
    int g = dst_argb[1];
    int r = dst_argb[2];
    int a = dst_argb[3];
    dst_argb[0] = table_argb[b * 4 + 0];
    dst_argb[1] = table_argb[g * 4 + 1];
    dst_argb[2] = table_argb[r * 4 + 2];
    dst_argb[3] = table_argb[a * 4 + 3];
    dst_argb += 4;
  }
}

// Apply color table to a row of image.
void RGBColorTableRow_C(uint8_t* dst_argb,
                        const uint8_t* table_argb,
                        int width) {
  int x;
  for (x = 0; x < width; ++x) {
    int b = dst_argb[0];
    int g = dst_argb[1];
    int r = dst_argb[2];
    dst_argb[0] = table_argb[b * 4 + 0];
    dst_argb[1] = table_argb[g * 4 + 1];
    dst_argb[2] = table_argb[r * 4 + 2];
    dst_argb += 4;
  }
}

void ARGBQuantizeRow_C(uint8_t* dst_argb,
                       int scale,
                       int interval_size,
                       int interval_offset,
                       int width) {
  int x;
  for (x = 0; x < width; ++x) {
    int b = dst_argb[0];
    int g = dst_argb[1];
    int r = dst_argb[2];
    dst_argb[0] = (b * scale >> 16) * interval_size + interval_offset;
    dst_argb[1] = (g * scale >> 16) * interval_size + interval_offset;
    dst_argb[2] = (r * scale >> 16) * interval_size + interval_offset;
    dst_argb += 4;
  }
}

#define REPEAT8(v) (v) | ((v) << 8)
#define SHADE(f, v) v* f >> 24

void ARGBShadeRow_C(const uint8_t* src_argb,
                    uint8_t* dst_argb,
                    int width,
                    uint32_t value) {
  const uint32_t b_scale = REPEAT8(value & 0xff);
  const uint32_t g_scale = REPEAT8((value >> 8) & 0xff);
  const uint32_t r_scale = REPEAT8((value >> 16) & 0xff);
  const uint32_t a_scale = REPEAT8(value >> 24);

  int i;
  for (i = 0; i < width; ++i) {
    const uint32_t b = REPEAT8(src_argb[0]);
    const uint32_t g = REPEAT8(src_argb[1]);
    const uint32_t r = REPEAT8(src_argb[2]);
    const uint32_t a = REPEAT8(src_argb[3]);
    dst_argb[0] = SHADE(b, b_scale);
    dst_argb[1] = SHADE(g, g_scale);
    dst_argb[2] = SHADE(r, r_scale);
    dst_argb[3] = SHADE(a, a_scale);
    src_argb += 4;
    dst_argb += 4;
  }
}
#undef REPEAT8
#undef SHADE

#define REPEAT8(v) (v) | ((v) << 8)
#define SHADE(f, v) v* f >> 16

void ARGBMultiplyRow_C(const uint8_t* src_argb0,
                       const uint8_t* src_argb1,
                       uint8_t* dst_argb,
                       int width) {
  int i;
  for (i = 0; i < width; ++i) {
    const uint32_t b = REPEAT8(src_argb0[0]);
    const uint32_t g = REPEAT8(src_argb0[1]);
    const uint32_t r = REPEAT8(src_argb0[2]);
    const uint32_t a = REPEAT8(src_argb0[3]);
    const uint32_t b_scale = src_argb1[0];
    const uint32_t g_scale = src_argb1[1];
    const uint32_t r_scale = src_argb1[2];
    const uint32_t a_scale = src_argb1[3];
    dst_argb[0] = SHADE(b, b_scale);
    dst_argb[1] = SHADE(g, g_scale);
    dst_argb[2] = SHADE(r, r_scale);
    dst_argb[3] = SHADE(a, a_scale);
    src_argb0 += 4;
    src_argb1 += 4;
    dst_argb += 4;
  }
}
#undef REPEAT8
#undef SHADE

#define SHADE(f, v) clamp255(v + f)

void ARGBAddRow_C(const uint8_t* src_argb0,
                  const uint8_t* src_argb1,
                  uint8_t* dst_argb,
                  int width) {
  int i;
  for (i = 0; i < width; ++i) {
    const int b = src_argb0[0];
    const int g = src_argb0[1];
    const int r = src_argb0[2];
    const int a = src_argb0[3];
    const int b_add = src_argb1[0];
    const int g_add = src_argb1[1];
    const int r_add = src_argb1[2];
    const int a_add = src_argb1[3];
    dst_argb[0] = SHADE(b, b_add);
    dst_argb[1] = SHADE(g, g_add);
    dst_argb[2] = SHADE(r, r_add);
    dst_argb[3] = SHADE(a, a_add);
    src_argb0 += 4;
    src_argb1 += 4;
    dst_argb += 4;
  }
}
#undef SHADE

#define SHADE(f, v) clamp0(f - v)

void ARGBSubtractRow_C(const uint8_t* src_argb0,
                       const uint8_t* src_argb1,
                       uint8_t* dst_argb,
                       int width) {
  int i;
  for (i = 0; i < width; ++i) {
    const int b = src_argb0[0];
    const int g = src_argb0[1];
    const int r = src_argb0[2];
    const int a = src_argb0[3];
    const int b_sub = src_argb1[0];
    const int g_sub = src_argb1[1];
    const int r_sub = src_argb1[2];
    const int a_sub = src_argb1[3];
    dst_argb[0] = SHADE(b, b_sub);
    dst_argb[1] = SHADE(g, g_sub);
    dst_argb[2] = SHADE(r, r_sub);
    dst_argb[3] = SHADE(a, a_sub);
    src_argb0 += 4;
    src_argb1 += 4;
    dst_argb += 4;
  }
}
#undef SHADE

// Sobel functions which mimics SSSE3.
void SobelXRow_C(const uint8_t* src_y0,
                 const uint8_t* src_y1,
                 const uint8_t* src_y2,
                 uint8_t* dst_sobelx,
                 int width) {
  int i;
  for (i = 0; i < width; ++i) {
    int a = src_y0[i];
    int b = src_y1[i];
    int c = src_y2[i];
    int a_sub = src_y0[i + 2];
    int b_sub = src_y1[i + 2];
    int c_sub = src_y2[i + 2];
    int a_diff = a - a_sub;
    int b_diff = b - b_sub;
    int c_diff = c - c_sub;
    int sobel = Abs(a_diff + b_diff * 2 + c_diff);
    dst_sobelx[i] = (uint8_t)(clamp255(sobel));
  }
}

void SobelYRow_C(const uint8_t* src_y0,
                 const uint8_t* src_y1,
                 uint8_t* dst_sobely,
                 int width) {
  int i;
  for (i = 0; i < width; ++i) {
    int a = src_y0[i + 0];
    int b = src_y0[i + 1];
    int c = src_y0[i + 2];
    int a_sub = src_y1[i + 0];
    int b_sub = src_y1[i + 1];
    int c_sub = src_y1[i + 2];
    int a_diff = a - a_sub;
    int b_diff = b - b_sub;
    int c_diff = c - c_sub;
    int sobel = Abs(a_diff + b_diff * 2 + c_diff);
    dst_sobely[i] = (uint8_t)(clamp255(sobel));
  }
}

void SobelRow_C(const uint8_t* src_sobelx,
                const uint8_t* src_sobely,
                uint8_t* dst_argb,
                int width) {
  int i;
  for (i = 0; i < width; ++i) {
    int r = src_sobelx[i];
    int b = src_sobely[i];
    int s = clamp255(r + b);
    dst_argb[0] = (uint8_t)(s);
    dst_argb[1] = (uint8_t)(s);
    dst_argb[2] = (uint8_t)(s);
    dst_argb[3] = (uint8_t)(255u);
    dst_argb += 4;
  }
}

void SobelToPlaneRow_C(const uint8_t* src_sobelx,
                       const uint8_t* src_sobely,
                       uint8_t* dst_y,
                       int width) {
  int i;
  for (i = 0; i < width; ++i) {
    int r = src_sobelx[i];
    int b = src_sobely[i];
    int s = clamp255(r + b);
    dst_y[i] = (uint8_t)(s);
  }
}

void SobelXYRow_C(const uint8_t* src_sobelx,
                  const uint8_t* src_sobely,
                  uint8_t* dst_argb,
                  int width) {
  int i;
  for (i = 0; i < width; ++i) {
    int r = src_sobelx[i];
    int b = src_sobely[i];
    int g = clamp255(r + b);
    dst_argb[0] = (uint8_t)(b);
    dst_argb[1] = (uint8_t)(g);
    dst_argb[2] = (uint8_t)(r);
    dst_argb[3] = (uint8_t)(255u);
    dst_argb += 4;
  }
}

void J400ToARGBRow_C(const uint8_t* src_y, uint8_t* dst_argb, int width) {
  // Copy a Y to RGB.
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t y = src_y[0];
    dst_argb[2] = dst_argb[1] = dst_argb[0] = y;
    dst_argb[3] = 255u;
    dst_argb += 4;
    ++src_y;
  }
}

// TODO(fbarchard): Unify these structures to be platform independent.
// TODO(fbarchard): Generate SIMD structures from float matrix.

// BT.601 YUV to RGB reference
//  R = (Y - 16) * 1.164              - V * -1.596
//  G = (Y - 16) * 1.164 - U *  0.391 - V *  0.813
//  B = (Y - 16) * 1.164 - U * -2.018

// Y contribution to R,G,B.  Scale and bias.
#define YG 18997  /* round(1.164 * 64 * 256 * 256 / 257) */
#define YGB -1160 /* 1.164 * 64 * -16 + 64 / 2 */

// U and V contributions to R,G,B.
#define UB -128 /* max(-128, round(-2.018 * 64)) */
#define UG 25   /* round(0.391 * 64) */
#define VG 52   /* round(0.813 * 64) */
#define VR -102 /* round(-1.596 * 64) */

// Bias values to subtract 16 from Y and 128 from U and V.
#define BB (UB * 128 + YGB)
#define BG (UG * 128 + VG * 128 + YGB)
#define BR (VR * 128 + YGB)

#if defined(__aarch64__)  // 64 bit arm
const struct YuvConstants SIMD_ALIGNED(kYuvI601Constants) = {
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvuI601Constants) = {
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#elif defined(__arm__)  // 32 bit arm
const struct YuvConstants SIMD_ALIGNED(kYuvI601Constants) = {
    {-UB, -UB, -UB, -UB, -VR, -VR, -VR, -VR, 0, 0, 0, 0, 0, 0, 0, 0},
    {UG, UG, UG, UG, VG, VG, VG, VG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvuI601Constants) = {
    {-VR, -VR, -VR, -VR, -UB, -UB, -UB, -UB, 0, 0, 0, 0, 0, 0, 0, 0},
    {VG, VG, VG, VG, UG, UG, UG, UG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#else
const struct YuvConstants SIMD_ALIGNED(kYuvI601Constants) = {
    {UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0,
     UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0},
    {UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG,
     UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG},
    {0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR,
     0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
const struct YuvConstants SIMD_ALIGNED(kYvuI601Constants) = {
    {VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0,
     VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0},
    {VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG,
     VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG},
    {0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB,
     0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
#endif

#undef BB
#undef BG
#undef BR
#undef YGB
#undef UB
#undef UG
#undef VG
#undef VR
#undef YG

// JPEG YUV to RGB reference
// *  R = Y                - V * -1.40200
// *  G = Y - U *  0.34414 - V *  0.71414
// *  B = Y - U * -1.77200

// Y contribution to R,G,B.  Scale and bias.
#define YG 16320 /* round(1.000 * 64 * 256 * 256 / 257) */
#define YGB 32   /* 64 / 2 */

// U and V contributions to R,G,B.
#define UB -113 /* round(-1.77200 * 64) */
#define UG 22   /* round(0.34414 * 64) */
#define VG 46   /* round(0.71414  * 64) */
#define VR -90  /* round(-1.40200 * 64) */

// Bias values to round, and subtract 128 from U and V.
#define BB (UB * 128 + YGB)
#define BG (UG * 128 + VG * 128 + YGB)
#define BR (VR * 128 + YGB)

#if defined(__aarch64__)
const struct YuvConstants SIMD_ALIGNED(kYuvJPEGConstants) = {
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvuJPEGConstants) = {
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#elif defined(__arm__)
const struct YuvConstants SIMD_ALIGNED(kYuvJPEGConstants) = {
    {-UB, -UB, -UB, -UB, -VR, -VR, -VR, -VR, 0, 0, 0, 0, 0, 0, 0, 0},
    {UG, UG, UG, UG, VG, VG, VG, VG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvuJPEGConstants) = {
    {-VR, -VR, -VR, -VR, -UB, -UB, -UB, -UB, 0, 0, 0, 0, 0, 0, 0, 0},
    {VG, VG, VG, VG, UG, UG, UG, UG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#else
const struct YuvConstants SIMD_ALIGNED(kYuvJPEGConstants) = {
    {UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0,
     UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0},
    {UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG,
     UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG},
    {0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR,
     0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
const struct YuvConstants SIMD_ALIGNED(kYvuJPEGConstants) = {
    {VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0,
     VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0},
    {VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG,
     VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG},
    {0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB,
     0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
#endif

#undef BB
#undef BG
#undef BR
#undef YGB
#undef UB
#undef UG
#undef VG
#undef VR
#undef YG

// BT.709 YUV to RGB reference
//  R = (Y - 16) * 1.164              - V * -1.793
//  G = (Y - 16) * 1.164 - U *  0.213 - V *  0.533
//  B = (Y - 16) * 1.164 - U * -2.112
// See also http://www.equasys.de/colorconversion.html

// Y contribution to R,G,B.  Scale and bias.
#define YG 18997  /* round(1.164 * 64 * 256 * 256 / 257) */
#define YGB -1160 /* 1.164 * 64 * -16 + 64 / 2 */

// TODO(fbarchard): Find way to express 2.112 instead of 2.0.
// U and V contributions to R,G,B.
#define UB -128 /* max(-128, round(-2.112 * 64)) */
#define UG 14   /* round(0.213 * 64) */
#define VG 34   /* round(0.533  * 64) */
#define VR -115 /* round(-1.793 * 64) */

// Bias values to round, and subtract 128 from U and V.
#define BB (UB * 128 + YGB)
#define BG (UG * 128 + VG * 128 + YGB)
#define BR (VR * 128 + YGB)

#if defined(__aarch64__)
const struct YuvConstants SIMD_ALIGNED(kYuvH709Constants) = {
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvuH709Constants) = {
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#elif defined(__arm__)
const struct YuvConstants SIMD_ALIGNED(kYuvH709Constants) = {
    {-UB, -UB, -UB, -UB, -VR, -VR, -VR, -VR, 0, 0, 0, 0, 0, 0, 0, 0},
    {UG, UG, UG, UG, VG, VG, VG, VG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvuH709Constants) = {
    {-VR, -VR, -VR, -VR, -UB, -UB, -UB, -UB, 0, 0, 0, 0, 0, 0, 0, 0},
    {VG, VG, VG, VG, UG, UG, UG, UG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#else
const struct YuvConstants SIMD_ALIGNED(kYuvH709Constants) = {
    {UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0,
     UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0},
    {UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG,
     UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG},
    {0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR,
     0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
const struct YuvConstants SIMD_ALIGNED(kYvuH709Constants) = {
    {VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0,
     VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0},
    {VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG,
     VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG},
    {0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB,
     0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
#endif

#undef BB
#undef BG
#undef BR
#undef YGB
#undef UB
#undef UG
#undef VG
#undef VR
#undef YG

// BT.2020 YUV to RGB reference
//  R = (Y - 16) * 1.164384                - V * -1.67867
//  G = (Y - 16) * 1.164384 - U * 0.187326 - V *  0.65042
//  B = (Y - 16) * 1.164384 - U * -2.14177

// Y contribution to R,G,B.  Scale and bias.
#define YG 19003  /* round(1.164384 * 64 * 256 * 256 / 257) */
#define YGB -1160 /* 1.164384 * 64 * -16 + 64 / 2 */

// TODO(fbarchard): Improve accuracy; the B channel is off by 7%.
// U and V contributions to R,G,B.
#define UB -128 /* max(-128, round(-2.142 * 64)) */
#define UG 12   /* round(0.187326 * 64) */
#define VG 42   /* round(0.65042 * 64) */
#define VR -107 /* round(-1.67867 * 64) */

// Bias values to round, and subtract 128 from U and V.
#define BB (UB * 128 + YGB)
#define BG (UG * 128 + VG * 128 + YGB)
#define BR (VR * 128 + YGB)

#if defined(__aarch64__)
const struct YuvConstants SIMD_ALIGNED(kYuv2020Constants) = {
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {-UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {UG, VG, UG, VG, UG, VG, UG, VG},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvu2020Constants) = {
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {-VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {VG, UG, VG, UG, VG, UG, VG, UG},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#elif defined(__arm__)
const struct YuvConstants SIMD_ALIGNED(kYuv2020Constants) = {
    {-UB, -UB, -UB, -UB, -VR, -VR, -VR, -VR, 0, 0, 0, 0, 0, 0, 0, 0},
    {UG, UG, UG, UG, VG, VG, VG, VG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BB, BG, BR, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
const struct YuvConstants SIMD_ALIGNED(kYvu2020Constants) = {
    {-VR, -VR, -VR, -VR, -UB, -UB, -UB, -UB, 0, 0, 0, 0, 0, 0, 0, 0},
    {VG, VG, VG, VG, UG, UG, UG, UG, 0, 0, 0, 0, 0, 0, 0, 0},
    {BR, BG, BB, YGB, 0, 0, 0, 0},
    {0x0101 * YG, YG, 0, 0}};
#else
const struct YuvConstants SIMD_ALIGNED(kYuv2020Constants) = {
    {UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0,
     UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0},
    {UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG,
     UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG},
    {0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR,
     0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
const struct YuvConstants SIMD_ALIGNED(kYvu2020Constants) = {
    {VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0,
     VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0, VR, 0},
    {VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG,
     VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG, VG, UG},
    {0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB,
     0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB, 0, UB},
    {BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR, BR},
    {BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG, BG},
    {BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB, BB},
    {YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG, YG},
    {YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB, YGB,
     YGB}};
#endif

#undef BB
#undef BG
#undef BR
#undef YGB
#undef UB
#undef UG
#undef VG
#undef VR
#undef YG

// C reference code that mimics the YUV assembly.
// Reads 8 bit YUV and leaves result as 16 bit.
static __inline void YuvPixel(uint8_t y,
                              uint8_t u,
                              uint8_t v,
                              uint8_t* b,
                              uint8_t* g,
                              uint8_t* r,
                              const struct YuvConstants* yuvconstants) {
#if defined(__aarch64__)
  int ub = -yuvconstants->kUVToRB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[1];
  int vr = -yuvconstants->kUVToRB[1];
  int bb = yuvconstants->kUVBiasBGR[0];
  int bg = yuvconstants->kUVBiasBGR[1];
  int br = yuvconstants->kUVBiasBGR[2];
  int yg = yuvconstants->kYToRgb[1];
#elif defined(__arm__)
  int ub = -yuvconstants->kUVToRB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[4];
  int vr = -yuvconstants->kUVToRB[4];
  int bb = yuvconstants->kUVBiasBGR[0];
  int bg = yuvconstants->kUVBiasBGR[1];
  int br = yuvconstants->kUVBiasBGR[2];
  int yg = yuvconstants->kYToRgb[1];
#else
  int ub = yuvconstants->kUVToB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[1];
  int vr = yuvconstants->kUVToR[1];
  int bb = yuvconstants->kUVBiasB[0];
  int bg = yuvconstants->kUVBiasG[0];
  int br = yuvconstants->kUVBiasR[0];
  int yg = yuvconstants->kYToRgb[0];
#endif

  uint32_t y1 = (uint32_t)(y * 0x0101 * yg) >> 16;
  *b = Clamp((int32_t)(-(u * ub) + y1 + bb) >> 6);
  *g = Clamp((int32_t)(-(u * ug + v * vg) + y1 + bg) >> 6);
  *r = Clamp((int32_t)(-(v * vr) + y1 + br) >> 6);
}

// Reads 8 bit YUV and leaves result as 16 bit.
static __inline void YuvPixel8_16(uint8_t y,
                                  uint8_t u,
                                  uint8_t v,
                                  int* b,
                                  int* g,
                                  int* r,
                                  const struct YuvConstants* yuvconstants) {
#if defined(__aarch64__)
  int ub = -yuvconstants->kUVToRB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[1];
  int vr = -yuvconstants->kUVToRB[1];
  int bb = yuvconstants->kUVBiasBGR[0];
  int bg = yuvconstants->kUVBiasBGR[1];
  int br = yuvconstants->kUVBiasBGR[2];
  int yg = yuvconstants->kYToRgb[1];
#elif defined(__arm__)
  int ub = -yuvconstants->kUVToRB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[4];
  int vr = -yuvconstants->kUVToRB[4];
  int bb = yuvconstants->kUVBiasBGR[0];
  int bg = yuvconstants->kUVBiasBGR[1];
  int br = yuvconstants->kUVBiasBGR[2];
  int yg = yuvconstants->kYToRgb[1];
#else
  int ub = yuvconstants->kUVToB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[1];
  int vr = yuvconstants->kUVToR[1];
  int bb = yuvconstants->kUVBiasB[0];
  int bg = yuvconstants->kUVBiasG[0];
  int br = yuvconstants->kUVBiasR[0];
  int yg = yuvconstants->kYToRgb[0];
#endif

  uint32_t y1 = (uint32_t)(y * 0x0101 * yg) >> 16;
  *b = (int)(-(u * ub) + y1 + bb);
  *g = (int)(-(u * ug + v * vg) + y1 + bg);
  *r = (int)(-(v * vr) + y1 + br);
}

// C reference code that mimics the YUV 16 bit assembly.
// Reads 10 bit YUV and leaves result as 16 bit.
static __inline void YuvPixel16(int16_t y,
                                int16_t u,
                                int16_t v,
                                int* b,
                                int* g,
                                int* r,
                                const struct YuvConstants* yuvconstants) {
#if defined(__aarch64__)
  int ub = -yuvconstants->kUVToRB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[1];
  int vr = -yuvconstants->kUVToRB[1];
  int bb = yuvconstants->kUVBiasBGR[0];
  int bg = yuvconstants->kUVBiasBGR[1];
  int br = yuvconstants->kUVBiasBGR[2];
  int yg = yuvconstants->kYToRgb[1];
#elif defined(__arm__)
  int ub = -yuvconstants->kUVToRB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[4];
  int vr = -yuvconstants->kUVToRB[4];
  int bb = yuvconstants->kUVBiasBGR[0];
  int bg = yuvconstants->kUVBiasBGR[1];
  int br = yuvconstants->kUVBiasBGR[2];
  int yg = yuvconstants->kYToRgb[1];
#else
  int ub = yuvconstants->kUVToB[0];
  int ug = yuvconstants->kUVToG[0];
  int vg = yuvconstants->kUVToG[1];
  int vr = yuvconstants->kUVToR[1];
  int bb = yuvconstants->kUVBiasB[0];
  int bg = yuvconstants->kUVBiasG[0];
  int br = yuvconstants->kUVBiasR[0];
  int yg = yuvconstants->kYToRgb[0];
#endif

  uint32_t y1 = (uint32_t)((y << 6) * yg) >> 16;
  u = clamp255(u >> 2);
  v = clamp255(v >> 2);
  *b = (int)(-(u * ub) + y1 + bb);
  *g = (int)(-(u * ug + v * vg) + y1 + bg);
  *r = (int)(-(v * vr) + y1 + br);
}

// C reference code that mimics the YUV 10 bit assembly.
// Reads 10 bit YUV and clamps down to 8 bit RGB.
static __inline void YuvPixel10(uint16_t y,
                                uint16_t u,
                                uint16_t v,
                                uint8_t* b,
                                uint8_t* g,
                                uint8_t* r,
                                const struct YuvConstants* yuvconstants) {
  int b16;
  int g16;
  int r16;
  YuvPixel16(y, u, v, &b16, &g16, &r16, yuvconstants);
  *b = Clamp(b16 >> 6);
  *g = Clamp(g16 >> 6);
  *r = Clamp(r16 >> 6);
}

// C reference code that mimics the YUV assembly.
// Reads 8 bit YUV and leaves result as 16 bit.
static __inline void YPixel(uint8_t y,
                            uint8_t* b,
                            uint8_t* g,
                            uint8_t* r,
                            const struct YuvConstants* yuvconstants) {
#if defined(__aarch64__) || defined(__arm__)
  int ygb = yuvconstants->kUVBiasBGR[3];
  int yg = yuvconstants->kYToRgb[1];
#else
  int ygb = yuvconstants->kYBiasToRgb[0];
  int yg = yuvconstants->kYToRgb[0];
#endif
  uint32_t y1 = (uint32_t)(y * 0x0101 * yg) >> 16;
  *b = Clamp(((int32_t)(y1) + ygb) >> 6);
  *g = Clamp(((int32_t)(y1) + ygb) >> 6);
  *r = Clamp(((int32_t)(y1) + ygb) >> 6);
}

#if !defined(LIBYUV_DISABLE_NEON) && \
    (defined(__ARM_NEON__) || defined(__aarch64__) || defined(LIBYUV_NEON))
// C mimic assembly.
// TODO(fbarchard): Remove subsampling from Neon.
void I444ToARGBRow_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint8_t u = (src_u[0] + src_u[1] + 1) >> 1;
    uint8_t v = (src_v[0] + src_v[1] + 1) >> 1;
    YuvPixel(src_y[0], u, v, rgb_buf + 0, rgb_buf + 1, rgb_buf + 2,
             yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel(src_y[1], u, v, rgb_buf + 4, rgb_buf + 5, rgb_buf + 6,
             yuvconstants);
    rgb_buf[7] = 255;
    src_y += 2;
    src_u += 2;
    src_v += 2;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}
#else
void I444ToARGBRow_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width; ++x) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    src_y += 1;
    src_u += 1;
    src_v += 1;
    rgb_buf += 4;  // Advance 1 pixel.
  }
}
#endif

// Also used for 420
void I422ToARGBRow_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel(src_y[1], src_u[0], src_v[0], rgb_buf + 4, rgb_buf + 5,
             rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_y += 2;
    src_u += 1;
    src_v += 1;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

// 10 bit YUV to ARGB
void I210ToARGBRow_C(const uint16_t* src_y,
                     const uint16_t* src_u,
                     const uint16_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel10(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
               rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel10(src_y[1], src_u[0], src_v[0], rgb_buf + 4, rgb_buf + 5,
               rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_y += 2;
    src_u += 1;
    src_v += 1;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel10(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
               rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

static void StoreAR30(uint8_t* rgb_buf, int b, int g, int r) {
  uint32_t ar30;
  b = b >> 4;  // convert 10.6 to 10 bit.
  g = g >> 4;
  r = r >> 4;
  b = Clamp10(b);
  g = Clamp10(g);
  r = Clamp10(r);
  ar30 = b | ((uint32_t)g << 10) | ((uint32_t)r << 20) | 0xc0000000;
  (*(uint32_t*)rgb_buf) = ar30;
}

// 10 bit YUV to 10 bit AR30
void I210ToAR30Row_C(const uint16_t* src_y,
                     const uint16_t* src_u,
                     const uint16_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  int b;
  int g;
  int r;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel16(src_y[0], src_u[0], src_v[0], &b, &g, &r, yuvconstants);
    StoreAR30(rgb_buf, b, g, r);
    YuvPixel16(src_y[1], src_u[0], src_v[0], &b, &g, &r, yuvconstants);
    StoreAR30(rgb_buf + 4, b, g, r);
    src_y += 2;
    src_u += 1;
    src_v += 1;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel16(src_y[0], src_u[0], src_v[0], &b, &g, &r, yuvconstants);
    StoreAR30(rgb_buf, b, g, r);
  }
}

// 8 bit YUV to 10 bit AR30
// Uses same code as 10 bit YUV bit shifts the 8 bit values up to 10 bits.
void I422ToAR30Row_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  int b;
  int g;
  int r;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel8_16(src_y[0], src_u[0], src_v[0], &b, &g, &r, yuvconstants);
    StoreAR30(rgb_buf, b, g, r);
    YuvPixel8_16(src_y[1], src_u[0], src_v[0], &b, &g, &r, yuvconstants);
    StoreAR30(rgb_buf + 4, b, g, r);
    src_y += 2;
    src_u += 1;
    src_v += 1;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel8_16(src_y[0], src_u[0], src_v[0], &b, &g, &r, yuvconstants);
    StoreAR30(rgb_buf, b, g, r);
  }
}

void I422AlphaToARGBRow_C(const uint8_t* src_y,
                          const uint8_t* src_u,
                          const uint8_t* src_v,
                          const uint8_t* src_a,
                          uint8_t* rgb_buf,
                          const struct YuvConstants* yuvconstants,
                          int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = src_a[0];
    YuvPixel(src_y[1], src_u[0], src_v[0], rgb_buf + 4, rgb_buf + 5,
             rgb_buf + 6, yuvconstants);
    rgb_buf[7] = src_a[1];
    src_y += 2;
    src_u += 1;
    src_v += 1;
    src_a += 2;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = src_a[0];
  }
}

void I422ToRGB24Row_C(const uint8_t* src_y,
                      const uint8_t* src_u,
                      const uint8_t* src_v,
                      uint8_t* rgb_buf,
                      const struct YuvConstants* yuvconstants,
                      int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    YuvPixel(src_y[1], src_u[0], src_v[0], rgb_buf + 3, rgb_buf + 4,
             rgb_buf + 5, yuvconstants);
    src_y += 2;
    src_u += 1;
    src_v += 1;
    rgb_buf += 6;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
  }
}

void I422ToARGB4444Row_C(const uint8_t* src_y,
                         const uint8_t* src_u,
                         const uint8_t* src_v,
                         uint8_t* dst_argb4444,
                         const struct YuvConstants* yuvconstants,
                         int width) {
  uint8_t b0;
  uint8_t g0;
  uint8_t r0;
  uint8_t b1;
  uint8_t g1;
  uint8_t r1;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], &b0, &g0, &r0, yuvconstants);
    YuvPixel(src_y[1], src_u[0], src_v[0], &b1, &g1, &r1, yuvconstants);
    b0 = b0 >> 4;
    g0 = g0 >> 4;
    r0 = r0 >> 4;
    b1 = b1 >> 4;
    g1 = g1 >> 4;
    r1 = r1 >> 4;
    *(uint32_t*)(dst_argb4444) = b0 | (g0 << 4) | (r0 << 8) | (b1 << 16) |
                                 (g1 << 20) | (r1 << 24) | 0xf000f000;
    src_y += 2;
    src_u += 1;
    src_v += 1;
    dst_argb4444 += 4;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], &b0, &g0, &r0, yuvconstants);
    b0 = b0 >> 4;
    g0 = g0 >> 4;
    r0 = r0 >> 4;
    *(uint16_t*)(dst_argb4444) = b0 | (g0 << 4) | (r0 << 8) | 0xf000;
  }
}

void I422ToARGB1555Row_C(const uint8_t* src_y,
                         const uint8_t* src_u,
                         const uint8_t* src_v,
                         uint8_t* dst_argb1555,
                         const struct YuvConstants* yuvconstants,
                         int width) {
  uint8_t b0;
  uint8_t g0;
  uint8_t r0;
  uint8_t b1;
  uint8_t g1;
  uint8_t r1;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], &b0, &g0, &r0, yuvconstants);
    YuvPixel(src_y[1], src_u[0], src_v[0], &b1, &g1, &r1, yuvconstants);
    b0 = b0 >> 3;
    g0 = g0 >> 3;
    r0 = r0 >> 3;
    b1 = b1 >> 3;
    g1 = g1 >> 3;
    r1 = r1 >> 3;
    *(uint32_t*)(dst_argb1555) = b0 | (g0 << 5) | (r0 << 10) | (b1 << 16) |
                                 (g1 << 21) | (r1 << 26) | 0x80008000;
    src_y += 2;
    src_u += 1;
    src_v += 1;
    dst_argb1555 += 4;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], &b0, &g0, &r0, yuvconstants);
    b0 = b0 >> 3;
    g0 = g0 >> 3;
    r0 = r0 >> 3;
    *(uint16_t*)(dst_argb1555) = b0 | (g0 << 5) | (r0 << 10) | 0x8000;
  }
}

void I422ToRGB565Row_C(const uint8_t* src_y,
                       const uint8_t* src_u,
                       const uint8_t* src_v,
                       uint8_t* dst_rgb565,
                       const struct YuvConstants* yuvconstants,
                       int width) {
  uint8_t b0;
  uint8_t g0;
  uint8_t r0;
  uint8_t b1;
  uint8_t g1;
  uint8_t r1;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], &b0, &g0, &r0, yuvconstants);
    YuvPixel(src_y[1], src_u[0], src_v[0], &b1, &g1, &r1, yuvconstants);
    b0 = b0 >> 3;
    g0 = g0 >> 2;
    r0 = r0 >> 3;
    b1 = b1 >> 3;
    g1 = g1 >> 2;
    r1 = r1 >> 3;
    *(uint32_t*)(dst_rgb565) =
        b0 | (g0 << 5) | (r0 << 11) | (b1 << 16) | (g1 << 21) | (r1 << 27);
    src_y += 2;
    src_u += 1;
    src_v += 1;
    dst_rgb565 += 4;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], &b0, &g0, &r0, yuvconstants);
    b0 = b0 >> 3;
    g0 = g0 >> 2;
    r0 = r0 >> 3;
    *(uint16_t*)(dst_rgb565) = b0 | (g0 << 5) | (r0 << 11);
  }
}

void NV12ToARGBRow_C(const uint8_t* src_y,
                     const uint8_t* src_uv,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_uv[0], src_uv[1], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel(src_y[1], src_uv[0], src_uv[1], rgb_buf + 4, rgb_buf + 5,
             rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_y += 2;
    src_uv += 2;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_uv[0], src_uv[1], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

void NV21ToARGBRow_C(const uint8_t* src_y,
                     const uint8_t* src_vu,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_vu[1], src_vu[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel(src_y[1], src_vu[1], src_vu[0], rgb_buf + 4, rgb_buf + 5,
             rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_y += 2;
    src_vu += 2;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_vu[1], src_vu[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

void NV12ToRGB24Row_C(const uint8_t* src_y,
                      const uint8_t* src_uv,
                      uint8_t* rgb_buf,
                      const struct YuvConstants* yuvconstants,
                      int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_uv[0], src_uv[1], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    YuvPixel(src_y[1], src_uv[0], src_uv[1], rgb_buf + 3, rgb_buf + 4,
             rgb_buf + 5, yuvconstants);
    src_y += 2;
    src_uv += 2;
    rgb_buf += 6;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_uv[0], src_uv[1], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
  }
}

void NV21ToRGB24Row_C(const uint8_t* src_y,
                      const uint8_t* src_vu,
                      uint8_t* rgb_buf,
                      const struct YuvConstants* yuvconstants,
                      int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_vu[1], src_vu[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    YuvPixel(src_y[1], src_vu[1], src_vu[0], rgb_buf + 3, rgb_buf + 4,
             rgb_buf + 5, yuvconstants);
    src_y += 2;
    src_vu += 2;
    rgb_buf += 6;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_vu[1], src_vu[0], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
  }
}

void NV12ToRGB565Row_C(const uint8_t* src_y,
                       const uint8_t* src_uv,
                       uint8_t* dst_rgb565,
                       const struct YuvConstants* yuvconstants,
                       int width) {
  uint8_t b0;
  uint8_t g0;
  uint8_t r0;
  uint8_t b1;
  uint8_t g1;
  uint8_t r1;
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_uv[0], src_uv[1], &b0, &g0, &r0, yuvconstants);
    YuvPixel(src_y[1], src_uv[0], src_uv[1], &b1, &g1, &r1, yuvconstants);
    b0 = b0 >> 3;
    g0 = g0 >> 2;
    r0 = r0 >> 3;
    b1 = b1 >> 3;
    g1 = g1 >> 2;
    r1 = r1 >> 3;
    *(uint32_t*)(dst_rgb565) =
        b0 | (g0 << 5) | (r0 << 11) | (b1 << 16) | (g1 << 21) | (r1 << 27);
    src_y += 2;
    src_uv += 2;
    dst_rgb565 += 4;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_uv[0], src_uv[1], &b0, &g0, &r0, yuvconstants);
    b0 = b0 >> 3;
    g0 = g0 >> 2;
    r0 = r0 >> 3;
    *(uint16_t*)(dst_rgb565) = b0 | (g0 << 5) | (r0 << 11);
  }
}

void YUY2ToARGBRow_C(const uint8_t* src_yuy2,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_yuy2[0], src_yuy2[1], src_yuy2[3], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel(src_yuy2[2], src_yuy2[1], src_yuy2[3], rgb_buf + 4, rgb_buf + 5,
             rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_yuy2 += 4;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_yuy2[0], src_yuy2[1], src_yuy2[3], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

void UYVYToARGBRow_C(const uint8_t* src_uyvy,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_uyvy[1], src_uyvy[0], src_uyvy[2], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YuvPixel(src_uyvy[3], src_uyvy[0], src_uyvy[2], rgb_buf + 4, rgb_buf + 5,
             rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_uyvy += 4;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_uyvy[1], src_uyvy[0], src_uyvy[2], rgb_buf + 0, rgb_buf + 1,
             rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

void I422ToRGBARow_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 1, rgb_buf + 2,
             rgb_buf + 3, yuvconstants);
    rgb_buf[0] = 255;
    YuvPixel(src_y[1], src_u[0], src_v[0], rgb_buf + 5, rgb_buf + 6,
             rgb_buf + 7, yuvconstants);
    rgb_buf[4] = 255;
    src_y += 2;
    src_u += 1;
    src_v += 1;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YuvPixel(src_y[0], src_u[0], src_v[0], rgb_buf + 1, rgb_buf + 2,
             rgb_buf + 3, yuvconstants);
    rgb_buf[0] = 255;
  }
}

void I400ToARGBRow_C(const uint8_t* src_y,
                     uint8_t* rgb_buf,
                     const struct YuvConstants* yuvconstants,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    YPixel(src_y[0], rgb_buf + 0, rgb_buf + 1, rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
    YPixel(src_y[1], rgb_buf + 4, rgb_buf + 5, rgb_buf + 6, yuvconstants);
    rgb_buf[7] = 255;
    src_y += 2;
    rgb_buf += 8;  // Advance 2 pixels.
  }
  if (width & 1) {
    YPixel(src_y[0], rgb_buf + 0, rgb_buf + 1, rgb_buf + 2, yuvconstants);
    rgb_buf[3] = 255;
  }
}

void MirrorRow_C(const uint8_t* src, uint8_t* dst, int width) {
  int x;
  src += width - 1;
  for (x = 0; x < width - 1; x += 2) {
    dst[x] = src[0];
    dst[x + 1] = src[-1];
    src -= 2;
  }
  if (width & 1) {
    dst[width - 1] = src[0];
  }
}

void MirrorUVRow_C(const uint8_t* src_uv, uint8_t* dst_uv, int width) {
  int x;
  src_uv += (width - 1) << 1;
  for (x = 0; x < width; ++x) {
    dst_uv[0] = src_uv[0];
    dst_uv[1] = src_uv[1];
    src_uv -= 2;
    dst_uv += 2;
  }
}

void MirrorSplitUVRow_C(const uint8_t* src_uv,
                        uint8_t* dst_u,
                        uint8_t* dst_v,
                        int width) {
  int x;
  src_uv += (width - 1) << 1;
  for (x = 0; x < width - 1; x += 2) {
    dst_u[x] = src_uv[0];
    dst_u[x + 1] = src_uv[-2];
    dst_v[x] = src_uv[1];
    dst_v[x + 1] = src_uv[-2 + 1];
    src_uv -= 4;
  }
  if (width & 1) {
    dst_u[width - 1] = src_uv[0];
    dst_v[width - 1] = src_uv[1];
  }
}

void ARGBMirrorRow_C(const uint8_t* src, uint8_t* dst, int width) {
  int x;
  const uint32_t* src32 = (const uint32_t*)(src);
  uint32_t* dst32 = (uint32_t*)(dst);
  src32 += width - 1;
  for (x = 0; x < width - 1; x += 2) {
    dst32[x] = src32[0];
    dst32[x + 1] = src32[-1];
    src32 -= 2;
  }
  if (width & 1) {
    dst32[width - 1] = src32[0];
  }
}

void RGB24MirrorRow_C(const uint8_t* src_rgb24, uint8_t* dst_rgb24, int width) {
  int x;
  src_rgb24 += width * 3 - 3;
  for (x = 0; x < width; ++x) {
    uint8_t b = src_rgb24[0];
    uint8_t g = src_rgb24[1];
    uint8_t r = src_rgb24[2];
    dst_rgb24[0] = b;
    dst_rgb24[1] = g;
    dst_rgb24[2] = r;
    src_rgb24 -= 3;
    dst_rgb24 += 3;
  }
}

void SplitUVRow_C(const uint8_t* src_uv,
                  uint8_t* dst_u,
                  uint8_t* dst_v,
                  int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_u[x] = src_uv[0];
    dst_u[x + 1] = src_uv[2];
    dst_v[x] = src_uv[1];
    dst_v[x + 1] = src_uv[3];
    src_uv += 4;
  }
  if (width & 1) {
    dst_u[width - 1] = src_uv[0];
    dst_v[width - 1] = src_uv[1];
  }
}

void MergeUVRow_C(const uint8_t* src_u,
                  const uint8_t* src_v,
                  uint8_t* dst_uv,
                  int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_uv[0] = src_u[x];
    dst_uv[1] = src_v[x];
    dst_uv[2] = src_u[x + 1];
    dst_uv[3] = src_v[x + 1];
    dst_uv += 4;
  }
  if (width & 1) {
    dst_uv[0] = src_u[width - 1];
    dst_uv[1] = src_v[width - 1];
  }
}

void SplitRGBRow_C(const uint8_t* src_rgb,
                   uint8_t* dst_r,
                   uint8_t* dst_g,
                   uint8_t* dst_b,
                   int width) {
  int x;
  for (x = 0; x < width; ++x) {
    dst_r[x] = src_rgb[0];
    dst_g[x] = src_rgb[1];
    dst_b[x] = src_rgb[2];
    src_rgb += 3;
  }
}

void MergeRGBRow_C(const uint8_t* src_r,
                   const uint8_t* src_g,
                   const uint8_t* src_b,
                   uint8_t* dst_rgb,
                   int width) {
  int x;
  for (x = 0; x < width; ++x) {
    dst_rgb[0] = src_r[x];
    dst_rgb[1] = src_g[x];
    dst_rgb[2] = src_b[x];
    dst_rgb += 3;
  }
}

// Use scale to convert lsb formats to msb, depending how many bits there are:
// 128 = 9 bits
// 64 = 10 bits
// 16 = 12 bits
// 1 = 16 bits
void MergeUVRow_16_C(const uint16_t* src_u,
                     const uint16_t* src_v,
                     uint16_t* dst_uv,
                     int scale,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_uv[0] = src_u[x] * scale;
    dst_uv[1] = src_v[x] * scale;
    dst_uv[2] = src_u[x + 1] * scale;
    dst_uv[3] = src_v[x + 1] * scale;
    dst_uv += 4;
  }
  if (width & 1) {
    dst_uv[0] = src_u[width - 1] * scale;
    dst_uv[1] = src_v[width - 1] * scale;
  }
}

void MultiplyRow_16_C(const uint16_t* src_y,
                      uint16_t* dst_y,
                      int scale,
                      int width) {
  int x;
  for (x = 0; x < width; ++x) {
    dst_y[x] = src_y[x] * scale;
  }
}

// Use scale to convert lsb formats to msb, depending how many bits there are:
// 32768 = 9 bits
// 16384 = 10 bits
// 4096 = 12 bits
// 256 = 16 bits
void Convert16To8Row_C(const uint16_t* src_y,
                       uint8_t* dst_y,
                       int scale,
                       int width) {
  int x;
  for (x = 0; x < width; ++x) {
    dst_y[x] = clamp255((src_y[x] * scale) >> 16);
  }
}

// Use scale to convert lsb formats to msb, depending how many bits there are:
// 1024 = 10 bits
void Convert8To16Row_C(const uint8_t* src_y,
                       uint16_t* dst_y,
                       int scale,
                       int width) {
  int x;
  scale *= 0x0101;  // replicates the byte.
  for (x = 0; x < width; ++x) {
    dst_y[x] = (src_y[x] * scale) >> 16;
  }
}

void CopyRow_C(const uint8_t* src, uint8_t* dst, int count) {
  memcpy(dst, src, count);
}

void CopyRow_16_C(const uint16_t* src, uint16_t* dst, int count) {
  memcpy(dst, src, count * 2);
}

void SetRow_C(uint8_t* dst, uint8_t v8, int width) {
  memset(dst, v8, width);
}

void ARGBSetRow_C(uint8_t* dst_argb, uint32_t v32, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    memcpy(dst_argb + x * sizeof v32, &v32, sizeof v32);
  }
}

// Filter 2 rows of YUY2 UV's (422) into U and V (420).
void YUY2ToUVRow_C(const uint8_t* src_yuy2,
                   int src_stride_yuy2,
                   uint8_t* dst_u,
                   uint8_t* dst_v,
                   int width) {
  // Output a row of UV values, filtering 2 rows of YUY2.
  int x;
  for (x = 0; x < width; x += 2) {
    dst_u[0] = (src_yuy2[1] + src_yuy2[src_stride_yuy2 + 1] + 1) >> 1;
    dst_v[0] = (src_yuy2[3] + src_yuy2[src_stride_yuy2 + 3] + 1) >> 1;
    src_yuy2 += 4;
    dst_u += 1;
    dst_v += 1;
  }
}

// Copy row of YUY2 UV's (422) into U and V (422).
void YUY2ToUV422Row_C(const uint8_t* src_yuy2,
                      uint8_t* dst_u,
                      uint8_t* dst_v,
                      int width) {
  // Output a row of UV values.
  int x;
  for (x = 0; x < width; x += 2) {
    dst_u[0] = src_yuy2[1];
    dst_v[0] = src_yuy2[3];
    src_yuy2 += 4;
    dst_u += 1;
    dst_v += 1;
  }
}

// Copy row of YUY2 Y's (422) into Y (420/422).
void YUY2ToYRow_C(const uint8_t* src_yuy2, uint8_t* dst_y, int width) {
  // Output a row of Y values.
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_y[x] = src_yuy2[0];
    dst_y[x + 1] = src_yuy2[2];
    src_yuy2 += 4;
  }
  if (width & 1) {
    dst_y[width - 1] = src_yuy2[0];
  }
}

// Filter 2 rows of UYVY UV's (422) into U and V (420).
void UYVYToUVRow_C(const uint8_t* src_uyvy,
                   int src_stride_uyvy,
                   uint8_t* dst_u,
                   uint8_t* dst_v,
                   int width) {
  // Output a row of UV values.
  int x;
  for (x = 0; x < width; x += 2) {
    dst_u[0] = (src_uyvy[0] + src_uyvy[src_stride_uyvy + 0] + 1) >> 1;
    dst_v[0] = (src_uyvy[2] + src_uyvy[src_stride_uyvy + 2] + 1) >> 1;
    src_uyvy += 4;
    dst_u += 1;
    dst_v += 1;
  }
}

// Copy row of UYVY UV's (422) into U and V (422).
void UYVYToUV422Row_C(const uint8_t* src_uyvy,
                      uint8_t* dst_u,
                      uint8_t* dst_v,
                      int width) {
  // Output a row of UV values.
  int x;
  for (x = 0; x < width; x += 2) {
    dst_u[0] = src_uyvy[0];
    dst_v[0] = src_uyvy[2];
    src_uyvy += 4;
    dst_u += 1;
    dst_v += 1;
  }
}

// Copy row of UYVY Y's (422) into Y (420/422).
void UYVYToYRow_C(const uint8_t* src_uyvy, uint8_t* dst_y, int width) {
  // Output a row of Y values.
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_y[x] = src_uyvy[1];
    dst_y[x + 1] = src_uyvy[3];
    src_uyvy += 4;
  }
  if (width & 1) {
    dst_y[width - 1] = src_uyvy[1];
  }
}

#define BLEND(f, b, a) clamp255((((256 - a) * b) >> 8) + f)

// Blend src_argb0 over src_argb1 and store to dst_argb.
// dst_argb may be src_argb0 or src_argb1.
// This code mimics the SSSE3 version for better testability.
void ARGBBlendRow_C(const uint8_t* src_argb0,
                    const uint8_t* src_argb1,
                    uint8_t* dst_argb,
                    int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    uint32_t fb = src_argb0[0];
    uint32_t fg = src_argb0[1];
    uint32_t fr = src_argb0[2];
    uint32_t a = src_argb0[3];
    uint32_t bb = src_argb1[0];
    uint32_t bg = src_argb1[1];
    uint32_t br = src_argb1[2];
    dst_argb[0] = BLEND(fb, bb, a);
    dst_argb[1] = BLEND(fg, bg, a);
    dst_argb[2] = BLEND(fr, br, a);
    dst_argb[3] = 255u;

    fb = src_argb0[4 + 0];
    fg = src_argb0[4 + 1];
    fr = src_argb0[4 + 2];
    a = src_argb0[4 + 3];
    bb = src_argb1[4 + 0];
    bg = src_argb1[4 + 1];
    br = src_argb1[4 + 2];
    dst_argb[4 + 0] = BLEND(fb, bb, a);
    dst_argb[4 + 1] = BLEND(fg, bg, a);
    dst_argb[4 + 2] = BLEND(fr, br, a);
    dst_argb[4 + 3] = 255u;
    src_argb0 += 8;
    src_argb1 += 8;
    dst_argb += 8;
  }

  if (width & 1) {
    uint32_t fb = src_argb0[0];
    uint32_t fg = src_argb0[1];
    uint32_t fr = src_argb0[2];
    uint32_t a = src_argb0[3];
    uint32_t bb = src_argb1[0];
    uint32_t bg = src_argb1[1];
    uint32_t br = src_argb1[2];
    dst_argb[0] = BLEND(fb, bb, a);
    dst_argb[1] = BLEND(fg, bg, a);
    dst_argb[2] = BLEND(fr, br, a);
    dst_argb[3] = 255u;
  }
}
#undef BLEND

#define UBLEND(f, b, a) (((a)*f) + ((255 - a) * b) + 255) >> 8
void BlendPlaneRow_C(const uint8_t* src0,
                     const uint8_t* src1,
                     const uint8_t* alpha,
                     uint8_t* dst,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst[0] = UBLEND(src0[0], src1[0], alpha[0]);
    dst[1] = UBLEND(src0[1], src1[1], alpha[1]);
    src0 += 2;
    src1 += 2;
    alpha += 2;
    dst += 2;
  }
  if (width & 1) {
    dst[0] = UBLEND(src0[0], src1[0], alpha[0]);
  }
}
#undef UBLEND

#if defined(__aarch64__) || defined(__arm__)
#define ATTENUATE(f, a) (f * a + 128) >> 8
#else
// This code mimics the SSSE3 version for better testability.
#define ATTENUATE(f, a) (a | (a << 8)) * (f | (f << 8)) >> 24
#endif

// Multiply source RGB by alpha and store to destination.
void ARGBAttenuateRow_C(const uint8_t* src_argb, uint8_t* dst_argb, int width) {
  int i;
  for (i = 0; i < width - 1; i += 2) {
    uint32_t b = src_argb[0];
    uint32_t g = src_argb[1];
    uint32_t r = src_argb[2];
    uint32_t a = src_argb[3];
    dst_argb[0] = ATTENUATE(b, a);
    dst_argb[1] = ATTENUATE(g, a);
    dst_argb[2] = ATTENUATE(r, a);
    dst_argb[3] = a;
    b = src_argb[4];
    g = src_argb[5];
    r = src_argb[6];
    a = src_argb[7];
    dst_argb[4] = ATTENUATE(b, a);
    dst_argb[5] = ATTENUATE(g, a);
    dst_argb[6] = ATTENUATE(r, a);
    dst_argb[7] = a;
    src_argb += 8;
    dst_argb += 8;
  }

  if (width & 1) {
    const uint32_t b = src_argb[0];
    const uint32_t g = src_argb[1];
    const uint32_t r = src_argb[2];
    const uint32_t a = src_argb[3];
    dst_argb[0] = ATTENUATE(b, a);
    dst_argb[1] = ATTENUATE(g, a);
    dst_argb[2] = ATTENUATE(r, a);
    dst_argb[3] = a;
  }
}
#undef ATTENUATE

// Divide source RGB by alpha and store to destination.
// b = (b * 255 + (a / 2)) / a;
// g = (g * 255 + (a / 2)) / a;
// r = (r * 255 + (a / 2)) / a;
// Reciprocal method is off by 1 on some values. ie 125
// 8.8 fixed point inverse table with 1.0 in upper short and 1 / a in lower.
#define T(a) 0x01000000 + (0x10000 / a)
const uint32_t fixed_invtbl8[256] = {
    0x01000000, 0x0100ffff, T(0x02), T(0x03),   T(0x04), T(0x05), T(0x06),
    T(0x07),    T(0x08),    T(0x09), T(0x0a),   T(0x0b), T(0x0c), T(0x0d),
    T(0x0e),    T(0x0f),    T(0x10), T(0x11),   T(0x12), T(0x13), T(0x14),
    T(0x15),    T(0x16),    T(0x17), T(0x18),   T(0x19), T(0x1a), T(0x1b),
    T(0x1c),    T(0x1d),    T(0x1e), T(0x1f),   T(0x20), T(0x21), T(0x22),
    T(0x23),    T(0x24),    T(0x25), T(0x26),   T(0x27), T(0x28), T(0x29),
    T(0x2a),    T(0x2b),    T(0x2c), T(0x2d),   T(0x2e), T(0x2f), T(0x30),
    T(0x31),    T(0x32),    T(0x33), T(0x34),   T(0x35), T(0x36), T(0x37),
    T(0x38),    T(0x39),    T(0x3a), T(0x3b),   T(0x3c), T(0x3d), T(0x3e),
    T(0x3f),    T(0x40),    T(0x41), T(0x42),   T(0x43), T(0x44), T(0x45),
    T(0x46),    T(0x47),    T(0x48), T(0x49),   T(0x4a), T(0x4b), T(0x4c),
    T(0x4d),    T(0x4e),    T(0x4f), T(0x50),   T(0x51), T(0x52), T(0x53),
    T(0x54),    T(0x55),    T(0x56), T(0x57),   T(0x58), T(0x59), T(0x5a),
    T(0x5b),    T(0x5c),    T(0x5d), T(0x5e),   T(0x5f), T(0x60), T(0x61),
    T(0x62),    T(0x63),    T(0x64), T(0x65),   T(0x66), T(0x67), T(0x68),
    T(0x69),    T(0x6a),    T(0x6b), T(0x6c),   T(0x6d), T(0x6e), T(0x6f),
    T(0x70),    T(0x71),    T(0x72), T(0x73),   T(0x74), T(0x75), T(0x76),
    T(0x77),    T(0x78),    T(0x79), T(0x7a),   T(0x7b), T(0x7c), T(0x7d),
    T(0x7e),    T(0x7f),    T(0x80), T(0x81),   T(0x82), T(0x83), T(0x84),
    T(0x85),    T(0x86),    T(0x87), T(0x88),   T(0x89), T(0x8a), T(0x8b),
    T(0x8c),    T(0x8d),    T(0x8e), T(0x8f),   T(0x90), T(0x91), T(0x92),
    T(0x93),    T(0x94),    T(0x95), T(0x96),   T(0x97), T(0x98), T(0x99),
    T(0x9a),    T(0x9b),    T(0x9c), T(0x9d),   T(0x9e), T(0x9f), T(0xa0),
    T(0xa1),    T(0xa2),    T(0xa3), T(0xa4),   T(0xa5), T(0xa6), T(0xa7),
    T(0xa8),    T(0xa9),    T(0xaa), T(0xab),   T(0xac), T(0xad), T(0xae),
    T(0xaf),    T(0xb0),    T(0xb1), T(0xb2),   T(0xb3), T(0xb4), T(0xb5),
    T(0xb6),    T(0xb7),    T(0xb8), T(0xb9),   T(0xba), T(0xbb), T(0xbc),
    T(0xbd),    T(0xbe),    T(0xbf), T(0xc0),   T(0xc1), T(0xc2), T(0xc3),
    T(0xc4),    T(0xc5),    T(0xc6), T(0xc7),   T(0xc8), T(0xc9), T(0xca),
    T(0xcb),    T(0xcc),    T(0xcd), T(0xce),   T(0xcf), T(0xd0), T(0xd1),
    T(0xd2),    T(0xd3),    T(0xd4), T(0xd5),   T(0xd6), T(0xd7), T(0xd8),
    T(0xd9),    T(0xda),    T(0xdb), T(0xdc),   T(0xdd), T(0xde), T(0xdf),
    T(0xe0),    T(0xe1),    T(0xe2), T(0xe3),   T(0xe4), T(0xe5), T(0xe6),
    T(0xe7),    T(0xe8),    T(0xe9), T(0xea),   T(0xeb), T(0xec), T(0xed),
    T(0xee),    T(0xef),    T(0xf0), T(0xf1),   T(0xf2), T(0xf3), T(0xf4),
    T(0xf5),    T(0xf6),    T(0xf7), T(0xf8),   T(0xf9), T(0xfa), T(0xfb),
    T(0xfc),    T(0xfd),    T(0xfe), 0x01000100};
#undef T

void ARGBUnattenuateRow_C(const uint8_t* src_argb,
                          uint8_t* dst_argb,
                          int width) {
  int i;
  for (i = 0; i < width; ++i) {
    uint32_t b = src_argb[0];
    uint32_t g = src_argb[1];
    uint32_t r = src_argb[2];
    const uint32_t a = src_argb[3];
    const uint32_t ia = fixed_invtbl8[a] & 0xffff;  // 8.8 fixed point
    b = (b * ia) >> 8;
    g = (g * ia) >> 8;
    r = (r * ia) >> 8;
    // Clamping should not be necessary but is free in assembly.
    dst_argb[0] = clamp255(b);
    dst_argb[1] = clamp255(g);
    dst_argb[2] = clamp255(r);
    dst_argb[3] = a;
    src_argb += 4;
    dst_argb += 4;
  }
}

void ComputeCumulativeSumRow_C(const uint8_t* row,
                               int32_t* cumsum,
                               const int32_t* previous_cumsum,
                               int width) {
  int32_t row_sum[4] = {0, 0, 0, 0};
  int x;
  for (x = 0; x < width; ++x) {
    row_sum[0] += row[x * 4 + 0];
    row_sum[1] += row[x * 4 + 1];
    row_sum[2] += row[x * 4 + 2];
    row_sum[3] += row[x * 4 + 3];
    cumsum[x * 4 + 0] = row_sum[0] + previous_cumsum[x * 4 + 0];
    cumsum[x * 4 + 1] = row_sum[1] + previous_cumsum[x * 4 + 1];
    cumsum[x * 4 + 2] = row_sum[2] + previous_cumsum[x * 4 + 2];
    cumsum[x * 4 + 3] = row_sum[3] + previous_cumsum[x * 4 + 3];
  }
}

void CumulativeSumToAverageRow_C(const int32_t* tl,
                                 const int32_t* bl,
                                 int w,
                                 int area,
                                 uint8_t* dst,
                                 int count) {
  float ooa = 1.0f / area;
  int i;
  for (i = 0; i < count; ++i) {
    dst[0] = (uint8_t)((bl[w + 0] + tl[0] - bl[0] - tl[w + 0]) * ooa);
    dst[1] = (uint8_t)((bl[w + 1] + tl[1] - bl[1] - tl[w + 1]) * ooa);
    dst[2] = (uint8_t)((bl[w + 2] + tl[2] - bl[2] - tl[w + 2]) * ooa);
    dst[3] = (uint8_t)((bl[w + 3] + tl[3] - bl[3] - tl[w + 3]) * ooa);
    dst += 4;
    tl += 4;
    bl += 4;
  }
}

// Copy pixels from rotated source to destination row with a slope.
LIBYUV_API
void ARGBAffineRow_C(const uint8_t* src_argb,
                     int src_argb_stride,
                     uint8_t* dst_argb,
                     const float* uv_dudv,
                     int width) {
  int i;
  // Render a row of pixels from source into a buffer.
  float uv[2];
  uv[0] = uv_dudv[0];
  uv[1] = uv_dudv[1];
  for (i = 0; i < width; ++i) {
    int x = (int)(uv[0]);
    int y = (int)(uv[1]);
    *(uint32_t*)(dst_argb) =
        *(const uint32_t*)(src_argb + y * src_argb_stride + x * 4);
    dst_argb += 4;
    uv[0] += uv_dudv[2];
    uv[1] += uv_dudv[3];
  }
}

// Blend 2 rows into 1.
static void HalfRow_C(const uint8_t* src_uv,
                      ptrdiff_t src_uv_stride,
                      uint8_t* dst_uv,
                      int width) {
  int x;
  for (x = 0; x < width; ++x) {
    dst_uv[x] = (src_uv[x] + src_uv[src_uv_stride + x] + 1) >> 1;
  }
}

static void HalfRow_16_C(const uint16_t* src_uv,
                         ptrdiff_t src_uv_stride,
                         uint16_t* dst_uv,
                         int width) {
  int x;
  for (x = 0; x < width; ++x) {
    dst_uv[x] = (src_uv[x] + src_uv[src_uv_stride + x] + 1) >> 1;
  }
}

// C version 2x2 -> 2x1.
void InterpolateRow_C(uint8_t* dst_ptr,
                      const uint8_t* src_ptr,
                      ptrdiff_t src_stride,
                      int width,
                      int source_y_fraction) {
  int y1_fraction = source_y_fraction;
  int y0_fraction = 256 - y1_fraction;
  const uint8_t* src_ptr1 = src_ptr + src_stride;
  int x;
  if (y1_fraction == 0) {
    memcpy(dst_ptr, src_ptr, width);
    return;
  }
  if (y1_fraction == 128) {
    HalfRow_C(src_ptr, src_stride, dst_ptr, width);
    return;
  }
  for (x = 0; x < width - 1; x += 2) {
    dst_ptr[0] =
        (src_ptr[0] * y0_fraction + src_ptr1[0] * y1_fraction + 128) >> 8;
    dst_ptr[1] =
        (src_ptr[1] * y0_fraction + src_ptr1[1] * y1_fraction + 128) >> 8;
    src_ptr += 2;
    src_ptr1 += 2;
    dst_ptr += 2;
  }
  if (width & 1) {
    dst_ptr[0] =
        (src_ptr[0] * y0_fraction + src_ptr1[0] * y1_fraction + 128) >> 8;
  }
}

void InterpolateRow_16_C(uint16_t* dst_ptr,
                         const uint16_t* src_ptr,
                         ptrdiff_t src_stride,
                         int width,
                         int source_y_fraction) {
  int y1_fraction = source_y_fraction;
  int y0_fraction = 256 - y1_fraction;
  const uint16_t* src_ptr1 = src_ptr + src_stride;
  int x;
  if (source_y_fraction == 0) {
    memcpy(dst_ptr, src_ptr, width * 2);
    return;
  }
  if (source_y_fraction == 128) {
    HalfRow_16_C(src_ptr, src_stride, dst_ptr, width);
    return;
  }
  for (x = 0; x < width - 1; x += 2) {
    dst_ptr[0] = (src_ptr[0] * y0_fraction + src_ptr1[0] * y1_fraction) >> 8;
    dst_ptr[1] = (src_ptr[1] * y0_fraction + src_ptr1[1] * y1_fraction) >> 8;
    src_ptr += 2;
    src_ptr1 += 2;
    dst_ptr += 2;
  }
  if (width & 1) {
    dst_ptr[0] = (src_ptr[0] * y0_fraction + src_ptr1[0] * y1_fraction) >> 8;
  }
}

// Use first 4 shuffler values to reorder ARGB channels.
void ARGBShuffleRow_C(const uint8_t* src_argb,
                      uint8_t* dst_argb,
                      const uint8_t* shuffler,
                      int width) {
  int index0 = shuffler[0];
  int index1 = shuffler[1];
  int index2 = shuffler[2];
  int index3 = shuffler[3];
  // Shuffle a row of ARGB.
  int x;
  for (x = 0; x < width; ++x) {
    // To support in-place conversion.
    uint8_t b = src_argb[index0];
    uint8_t g = src_argb[index1];
    uint8_t r = src_argb[index2];
    uint8_t a = src_argb[index3];
    dst_argb[0] = b;
    dst_argb[1] = g;
    dst_argb[2] = r;
    dst_argb[3] = a;
    src_argb += 4;
    dst_argb += 4;
  }
}

void I422ToYUY2Row_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* dst_frame,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_frame[0] = src_y[0];
    dst_frame[1] = src_u[0];
    dst_frame[2] = src_y[1];
    dst_frame[3] = src_v[0];
    dst_frame += 4;
    src_y += 2;
    src_u += 1;
    src_v += 1;
  }
  if (width & 1) {
    dst_frame[0] = src_y[0];
    dst_frame[1] = src_u[0];
    dst_frame[2] = 0;
    dst_frame[3] = src_v[0];
  }
}

void I422ToUYVYRow_C(const uint8_t* src_y,
                     const uint8_t* src_u,
                     const uint8_t* src_v,
                     uint8_t* dst_frame,
                     int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_frame[0] = src_u[0];
    dst_frame[1] = src_y[0];
    dst_frame[2] = src_v[0];
    dst_frame[3] = src_y[1];
    dst_frame += 4;
    src_y += 2;
    src_u += 1;
    src_v += 1;
  }
  if (width & 1) {
    dst_frame[0] = src_u[0];
    dst_frame[1] = src_y[0];
    dst_frame[2] = src_v[0];
    dst_frame[3] = 0;
  }
}

void ARGBPolynomialRow_C(const uint8_t* src_argb,
                         uint8_t* dst_argb,
                         const float* poly,
                         int width) {
  int i;
  for (i = 0; i < width; ++i) {
    float b = (float)(src_argb[0]);
    float g = (float)(src_argb[1]);
    float r = (float)(src_argb[2]);
    float a = (float)(src_argb[3]);
    float b2 = b * b;
    float g2 = g * g;
    float r2 = r * r;
    float a2 = a * a;
    float db = poly[0] + poly[4] * b;
    float dg = poly[1] + poly[5] * g;
    float dr = poly[2] + poly[6] * r;
    float da = poly[3] + poly[7] * a;
    float b3 = b2 * b;
    float g3 = g2 * g;
    float r3 = r2 * r;
    float a3 = a2 * a;
    db += poly[8] * b2;
    dg += poly[9] * g2;
    dr += poly[10] * r2;
    da += poly[11] * a2;
    db += poly[12] * b3;
    dg += poly[13] * g3;
    dr += poly[14] * r3;
    da += poly[15] * a3;

    dst_argb[0] = Clamp((int32_t)(db));
    dst_argb[1] = Clamp((int32_t)(dg));
    dst_argb[2] = Clamp((int32_t)(dr));
    dst_argb[3] = Clamp((int32_t)(da));
    src_argb += 4;
    dst_argb += 4;
  }
}

// Samples assumed to be unsigned in low 9, 10 or 12 bits.  Scale factor
// adjust the source integer range to the half float range desired.

// This magic constant is 2^-112. Multiplying by this
// is the same as subtracting 112 from the exponent, which
// is the difference in exponent bias between 32-bit and
// 16-bit floats. Once we've done this subtraction, we can
// simply extract the low bits of the exponent and the high
// bits of the mantissa from our float and we're done.

// Work around GCC 7 punning warning -Wstrict-aliasing
#if defined(__GNUC__)
typedef uint32_t __attribute__((__may_alias__)) uint32_alias_t;
#else
typedef uint32_t uint32_alias_t;
#endif

void HalfFloatRow_C(const uint16_t* src,
                    uint16_t* dst,
                    float scale,
                    int width) {
  int i;
  float mult = 1.9259299444e-34f * scale;
  for (i = 0; i < width; ++i) {
    float value = src[i] * mult;
    dst[i] = (uint16_t)((*(const uint32_alias_t*)&value) >> 13);
  }
}

void ByteToFloatRow_C(const uint8_t* src, float* dst, float scale, int width) {
  int i;
  for (i = 0; i < width; ++i) {
    float value = src[i] * scale;
    dst[i] = value;
  }
}

void ARGBLumaColorTableRow_C(const uint8_t* src_argb,
                             uint8_t* dst_argb,
                             int width,
                             const uint8_t* luma,
                             uint32_t lumacoeff) {
  uint32_t bc = lumacoeff & 0xff;
  uint32_t gc = (lumacoeff >> 8) & 0xff;
  uint32_t rc = (lumacoeff >> 16) & 0xff;

  int i;
  for (i = 0; i < width - 1; i += 2) {
    // Luminance in rows, color values in columns.
    const uint8_t* luma0 =
        ((src_argb[0] * bc + src_argb[1] * gc + src_argb[2] * rc) & 0x7F00u) +
        luma;
    const uint8_t* luma1;
    dst_argb[0] = luma0[src_argb[0]];
    dst_argb[1] = luma0[src_argb[1]];
    dst_argb[2] = luma0[src_argb[2]];
    dst_argb[3] = src_argb[3];
    luma1 =
        ((src_argb[4] * bc + src_argb[5] * gc + src_argb[6] * rc) & 0x7F00u) +
        luma;
    dst_argb[4] = luma1[src_argb[4]];
    dst_argb[5] = luma1[src_argb[5]];
    dst_argb[6] = luma1[src_argb[6]];
    dst_argb[7] = src_argb[7];
    src_argb += 8;
    dst_argb += 8;
  }
  if (width & 1) {
    // Luminance in rows, color values in columns.
    const uint8_t* luma0 =
        ((src_argb[0] * bc + src_argb[1] * gc + src_argb[2] * rc) & 0x7F00u) +
        luma;
    dst_argb[0] = luma0[src_argb[0]];
    dst_argb[1] = luma0[src_argb[1]];
    dst_argb[2] = luma0[src_argb[2]];
    dst_argb[3] = src_argb[3];
  }
}

void ARGBCopyAlphaRow_C(const uint8_t* src, uint8_t* dst, int width) {
  int i;
  for (i = 0; i < width - 1; i += 2) {
    dst[3] = src[3];
    dst[7] = src[7];
    dst += 8;
    src += 8;
  }
  if (width & 1) {
    dst[3] = src[3];
  }
}

void ARGBExtractAlphaRow_C(const uint8_t* src_argb, uint8_t* dst_a, int width) {
  int i;
  for (i = 0; i < width - 1; i += 2) {
    dst_a[0] = src_argb[3];
    dst_a[1] = src_argb[7];
    dst_a += 2;
    src_argb += 8;
  }
  if (width & 1) {
    dst_a[0] = src_argb[3];
  }
}

void ARGBCopyYToAlphaRow_C(const uint8_t* src, uint8_t* dst, int width) {
  int i;
  for (i = 0; i < width - 1; i += 2) {
    dst[3] = src[0];
    dst[7] = src[1];
    dst += 8;
    src += 2;
  }
  if (width & 1) {
    dst[3] = src[0];
  }
}

// Maximum temporary width for wrappers to process at a time, in pixels.
#define MAXTWIDTH 2048

#if !(defined(_MSC_VER) && defined(_M_IX86)) && \
    defined(HAS_I422TORGB565ROW_SSSE3)
// row_win.cc has asm version, but GCC uses 2 step wrapper.
void I422ToRGB565Row_SSSE3(const uint8_t* src_y,
                           const uint8_t* src_u,
                           const uint8_t* src_v,
                           uint8_t* dst_rgb565,
                           const struct YuvConstants* yuvconstants,
                           int width) {
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_SSSE3(src_y, src_u, src_v, row, yuvconstants, twidth);
    ARGBToRGB565Row_SSE2(row, dst_rgb565, twidth);
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_rgb565 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_I422TOARGB1555ROW_SSSE3)
void I422ToARGB1555Row_SSSE3(const uint8_t* src_y,
                             const uint8_t* src_u,
                             const uint8_t* src_v,
                             uint8_t* dst_argb1555,
                             const struct YuvConstants* yuvconstants,
                             int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_SSSE3(src_y, src_u, src_v, row, yuvconstants, twidth);
    ARGBToARGB1555Row_SSE2(row, dst_argb1555, twidth);
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_argb1555 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_I422TOARGB4444ROW_SSSE3)
void I422ToARGB4444Row_SSSE3(const uint8_t* src_y,
                             const uint8_t* src_u,
                             const uint8_t* src_v,
                             uint8_t* dst_argb4444,
                             const struct YuvConstants* yuvconstants,
                             int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_SSSE3(src_y, src_u, src_v, row, yuvconstants, twidth);
    ARGBToARGB4444Row_SSE2(row, dst_argb4444, twidth);
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_argb4444 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_NV12TORGB565ROW_SSSE3)
void NV12ToRGB565Row_SSSE3(const uint8_t* src_y,
                           const uint8_t* src_uv,
                           uint8_t* dst_rgb565,
                           const struct YuvConstants* yuvconstants,
                           int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    NV12ToARGBRow_SSSE3(src_y, src_uv, row, yuvconstants, twidth);
    ARGBToRGB565Row_SSE2(row, dst_rgb565, twidth);
    src_y += twidth;
    src_uv += twidth;
    dst_rgb565 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_NV12TORGB24ROW_SSSE3)
void NV12ToRGB24Row_SSSE3(const uint8_t* src_y,
                          const uint8_t* src_uv,
                          uint8_t* dst_rgb24,
                          const struct YuvConstants* yuvconstants,
                          int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    NV12ToARGBRow_SSSE3(src_y, src_uv, row, yuvconstants, twidth);
    ARGBToRGB24Row_SSSE3(row, dst_rgb24, twidth);
    src_y += twidth;
    src_uv += twidth;
    dst_rgb24 += twidth * 3;
    width -= twidth;
  }
}
#endif

#if defined(HAS_NV21TORGB24ROW_SSSE3)
void NV21ToRGB24Row_SSSE3(const uint8_t* src_y,
                          const uint8_t* src_vu,
                          uint8_t* dst_rgb24,
                          const struct YuvConstants* yuvconstants,
                          int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    NV21ToARGBRow_SSSE3(src_y, src_vu, row, yuvconstants, twidth);
    ARGBToRGB24Row_SSSE3(row, dst_rgb24, twidth);
    src_y += twidth;
    src_vu += twidth;
    dst_rgb24 += twidth * 3;
    width -= twidth;
  }
}
#endif

#if defined(HAS_NV12TORGB24ROW_AVX2)
void NV12ToRGB24Row_AVX2(const uint8_t* src_y,
                         const uint8_t* src_uv,
                         uint8_t* dst_rgb24,
                         const struct YuvConstants* yuvconstants,
                         int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    NV12ToARGBRow_AVX2(src_y, src_uv, row, yuvconstants, twidth);
#if defined(HAS_ARGBTORGB24ROW_AVX2)
    ARGBToRGB24Row_AVX2(row, dst_rgb24, twidth);
#else
    ARGBToRGB24Row_SSSE3(row, dst_rgb24, twidth);
#endif
    src_y += twidth;
    src_uv += twidth;
    dst_rgb24 += twidth * 3;
    width -= twidth;
  }
}
#endif

#if defined(HAS_NV21TORGB24ROW_AVX2)
void NV21ToRGB24Row_AVX2(const uint8_t* src_y,
                         const uint8_t* src_vu,
                         uint8_t* dst_rgb24,
                         const struct YuvConstants* yuvconstants,
                         int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    NV21ToARGBRow_AVX2(src_y, src_vu, row, yuvconstants, twidth);
#if defined(HAS_ARGBTORGB24ROW_AVX2)
    ARGBToRGB24Row_AVX2(row, dst_rgb24, twidth);
#else
    ARGBToRGB24Row_SSSE3(row, dst_rgb24, twidth);
#endif
    src_y += twidth;
    src_vu += twidth;
    dst_rgb24 += twidth * 3;
    width -= twidth;
  }
}
#endif

#if defined(HAS_I422TORGB565ROW_AVX2)
void I422ToRGB565Row_AVX2(const uint8_t* src_y,
                          const uint8_t* src_u,
                          const uint8_t* src_v,
                          uint8_t* dst_rgb565,
                          const struct YuvConstants* yuvconstants,
                          int width) {
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_AVX2(src_y, src_u, src_v, row, yuvconstants, twidth);
#if defined(HAS_ARGBTORGB565ROW_AVX2)
    ARGBToRGB565Row_AVX2(row, dst_rgb565, twidth);
#else
    ARGBToRGB565Row_SSE2(row, dst_rgb565, twidth);
#endif
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_rgb565 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_I422TOARGB1555ROW_AVX2)
void I422ToARGB1555Row_AVX2(const uint8_t* src_y,
                            const uint8_t* src_u,
                            const uint8_t* src_v,
                            uint8_t* dst_argb1555,
                            const struct YuvConstants* yuvconstants,
                            int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_AVX2(src_y, src_u, src_v, row, yuvconstants, twidth);
#if defined(HAS_ARGBTOARGB1555ROW_AVX2)
    ARGBToARGB1555Row_AVX2(row, dst_argb1555, twidth);
#else
    ARGBToARGB1555Row_SSE2(row, dst_argb1555, twidth);
#endif
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_argb1555 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_I422TOARGB4444ROW_AVX2)
void I422ToARGB4444Row_AVX2(const uint8_t* src_y,
                            const uint8_t* src_u,
                            const uint8_t* src_v,
                            uint8_t* dst_argb4444,
                            const struct YuvConstants* yuvconstants,
                            int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_AVX2(src_y, src_u, src_v, row, yuvconstants, twidth);
#if defined(HAS_ARGBTOARGB4444ROW_AVX2)
    ARGBToARGB4444Row_AVX2(row, dst_argb4444, twidth);
#else
    ARGBToARGB4444Row_SSE2(row, dst_argb4444, twidth);
#endif
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_argb4444 += twidth * 2;
    width -= twidth;
  }
}
#endif

#if defined(HAS_I422TORGB24ROW_AVX2)
void I422ToRGB24Row_AVX2(const uint8_t* src_y,
                         const uint8_t* src_u,
                         const uint8_t* src_v,
                         uint8_t* dst_rgb24,
                         const struct YuvConstants* yuvconstants,
                         int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    I422ToARGBRow_AVX2(src_y, src_u, src_v, row, yuvconstants, twidth);
#if defined(HAS_ARGBTORGB24ROW_AVX2)
    ARGBToRGB24Row_AVX2(row, dst_rgb24, twidth);
#else
    ARGBToRGB24Row_SSSE3(row, dst_rgb24, twidth);
#endif
    src_y += twidth;
    src_u += twidth / 2;
    src_v += twidth / 2;
    dst_rgb24 += twidth * 3;
    width -= twidth;
  }
}
#endif

#if defined(HAS_NV12TORGB565ROW_AVX2)
void NV12ToRGB565Row_AVX2(const uint8_t* src_y,
                          const uint8_t* src_uv,
                          uint8_t* dst_rgb565,
                          const struct YuvConstants* yuvconstants,
                          int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    NV12ToARGBRow_AVX2(src_y, src_uv, row, yuvconstants, twidth);
#if defined(HAS_ARGBTORGB565ROW_AVX2)
    ARGBToRGB565Row_AVX2(row, dst_rgb565, twidth);
#else
    ARGBToRGB565Row_SSE2(row, dst_rgb565, twidth);
#endif
    src_y += twidth;
    src_uv += twidth;
    dst_rgb565 += twidth * 2;
    width -= twidth;
  }
}
#endif

#ifdef HAS_RGB24TOYJROW_AVX2
// Convert 16 RGB24 pixels (64 bytes) to 16 YJ values.
void RGB24ToYJRow_AVX2(const uint8_t* src_rgb24, uint8_t* dst_yj, int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    RGB24ToARGBRow_SSSE3(src_rgb24, row, twidth);
    ARGBToYJRow_AVX2(row, dst_yj, twidth);
    src_rgb24 += twidth * 3;
    dst_yj += twidth;
    width -= twidth;
  }
}
#endif  // HAS_RGB24TOYJROW_AVX2

#ifdef HAS_RAWTOYJROW_AVX2
// Convert 16 RAW pixels (64 bytes) to 16 YJ values.
void RAWToYJRow_AVX2(const uint8_t* src_raw, uint8_t* dst_yj, int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    RAWToARGBRow_SSSE3(src_raw, row, twidth);
    ARGBToYJRow_AVX2(row, dst_yj, twidth);
    src_raw += twidth * 3;
    dst_yj += twidth;
    width -= twidth;
  }
}
#endif  // HAS_RAWTOYJROW_AVX2

#ifdef HAS_RGB24TOYJROW_SSSE3
// Convert 16 RGB24 pixels (64 bytes) to 16 YJ values.
void RGB24ToYJRow_SSSE3(const uint8_t* src_rgb24, uint8_t* dst_yj, int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    RGB24ToARGBRow_SSSE3(src_rgb24, row, twidth);
    ARGBToYJRow_SSSE3(row, dst_yj, twidth);
    src_rgb24 += twidth * 3;
    dst_yj += twidth;
    width -= twidth;
  }
}
#endif  // HAS_RGB24TOYJROW_SSSE3

#ifdef HAS_RAWTOYJROW_SSSE3
// Convert 16 RAW pixels (64 bytes) to 16 YJ values.
void RAWToYJRow_SSSE3(const uint8_t* src_raw, uint8_t* dst_yj, int width) {
  // Row buffer for intermediate ARGB pixels.
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
  while (width > 0) {
    int twidth = width > MAXTWIDTH ? MAXTWIDTH : width;
    RAWToARGBRow_SSSE3(src_raw, row, twidth);
    ARGBToYJRow_SSSE3(row, dst_yj, twidth);
    src_raw += twidth * 3;
    dst_yj += twidth;
    width -= twidth;
  }
}
#endif  // HAS_RAWTOYJROW_SSSE3

float ScaleSumSamples_C(const float* src, float* dst, float scale, int width) {
  float fsum = 0.f;
  int i;
  for (i = 0; i < width; ++i) {
    float v = *src++;
    fsum += v * v;
    *dst++ = v * scale;
  }
  return fsum;
}

float ScaleMaxSamples_C(const float* src, float* dst, float scale, int width) {
  float fmax = 0.f;
  int i;
  for (i = 0; i < width; ++i) {
    float v = *src++;
    float vs = v * scale;
    fmax = (v > fmax) ? v : fmax;
    *dst++ = vs;
  }
  return fmax;
}

void ScaleSamples_C(const float* src, float* dst, float scale, int width) {
  int i;
  for (i = 0; i < width; ++i) {
    *dst++ = *src++ * scale;
  }
}

void GaussRow_C(const uint32_t* src, uint16_t* dst, int width) {
  int i;
  for (i = 0; i < width; ++i) {
    *dst++ =
        (src[0] + src[1] * 4 + src[2] * 6 + src[3] * 4 + src[4] + 128) >> 8;
    ++src;
  }
}

// filter 5 rows with 1, 4, 6, 4, 1 coefficients to produce 1 row.
void GaussCol_C(const uint16_t* src0,
                const uint16_t* src1,
                const uint16_t* src2,
                const uint16_t* src3,
                const uint16_t* src4,
                uint32_t* dst,
                int width) {
  int i;
  for (i = 0; i < width; ++i) {
    *dst++ = *src0++ + *src1++ * 4 + *src2++ * 6 + *src3++ * 4 + *src4++;
  }
}

void GaussRow_F32_C(const float* src, float* dst, int width) {
  int i;
  for (i = 0; i < width; ++i) {
    *dst++ = (src[0] + src[1] * 4 + src[2] * 6 + src[3] * 4 + src[4]) *
             (1.0f / 256.0f);
    ++src;
  }
}

// filter 5 rows with 1, 4, 6, 4, 1 coefficients to produce 1 row.
void GaussCol_F32_C(const float* src0,
                    const float* src1,
                    const float* src2,
                    const float* src3,
                    const float* src4,
                    float* dst,
                    int width) {
  int i;
  for (i = 0; i < width; ++i) {
    *dst++ = *src0++ + *src1++ * 4 + *src2++ * 6 + *src3++ * 4 + *src4++;
  }
}

// Convert biplanar NV21 to packed YUV24
void NV21ToYUV24Row_C(const uint8_t* src_y,
                      const uint8_t* src_vu,
                      uint8_t* dst_yuv24,
                      int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_yuv24[0] = src_vu[0];  // V
    dst_yuv24[1] = src_vu[1];  // U
    dst_yuv24[2] = src_y[0];   // Y0
    dst_yuv24[3] = src_vu[0];  // V
    dst_yuv24[4] = src_vu[1];  // U
    dst_yuv24[5] = src_y[1];   // Y1
    src_y += 2;
    src_vu += 2;
    dst_yuv24 += 6;  // Advance 2 pixels.
  }
  if (width & 1) {
    dst_yuv24[0] = src_vu[0];  // V
    dst_yuv24[1] = src_vu[1];  // U
    dst_yuv24[2] = src_y[0];   // Y0
  }
}

// Filter 2 rows of AYUV UV's (444) into UV (420).
void AYUVToUVRow_C(const uint8_t* src_ayuv,
                   int src_stride_ayuv,
                   uint8_t* dst_uv,
                   int width) {
  // Output a row of UV values, filtering 2x2 rows of AYUV.
  int x;
  for (x = 0; x < width; x += 2) {
    dst_uv[0] = (src_ayuv[1] + src_ayuv[5] + src_ayuv[src_stride_ayuv + 1] +
                 src_ayuv[src_stride_ayuv + 5] + 2) >>
                2;
    dst_uv[1] = (src_ayuv[0] + src_ayuv[4] + src_ayuv[src_stride_ayuv + 0] +
                 src_ayuv[src_stride_ayuv + 4] + 2) >>
                2;
    src_ayuv += 8;
    dst_uv += 2;
  }
  if (width & 1) {
    dst_uv[0] = (src_ayuv[0] + src_ayuv[0] + src_ayuv[src_stride_ayuv + 0] +
                 src_ayuv[src_stride_ayuv + 0] + 2) >>
                2;
    dst_uv[1] = (src_ayuv[1] + src_ayuv[1] + src_ayuv[src_stride_ayuv + 1] +
                 src_ayuv[src_stride_ayuv + 1] + 2) >>
                2;
  }
}

// Filter 2 rows of AYUV UV's (444) into VU (420).
void AYUVToVURow_C(const uint8_t* src_ayuv,
                   int src_stride_ayuv,
                   uint8_t* dst_vu,
                   int width) {
  // Output a row of VU values, filtering 2x2 rows of AYUV.
  int x;
  for (x = 0; x < width; x += 2) {
    dst_vu[0] = (src_ayuv[0] + src_ayuv[4] + src_ayuv[src_stride_ayuv + 0] +
                 src_ayuv[src_stride_ayuv + 4] + 2) >>
                2;
    dst_vu[1] = (src_ayuv[1] + src_ayuv[5] + src_ayuv[src_stride_ayuv + 1] +
                 src_ayuv[src_stride_ayuv + 5] + 2) >>
                2;
    src_ayuv += 8;
    dst_vu += 2;
  }
  if (width & 1) {
    dst_vu[0] = (src_ayuv[0] + src_ayuv[0] + src_ayuv[src_stride_ayuv + 0] +
                 src_ayuv[src_stride_ayuv + 0] + 2) >>
                2;
    dst_vu[1] = (src_ayuv[1] + src_ayuv[1] + src_ayuv[src_stride_ayuv + 1] +
                 src_ayuv[src_stride_ayuv + 1] + 2) >>
                2;
  }
}

// Copy row of AYUV Y's into Y
void AYUVToYRow_C(const uint8_t* src_ayuv, uint8_t* dst_y, int width) {
  // Output a row of Y values.
  int x;
  for (x = 0; x < width; ++x) {
    dst_y[x] = src_ayuv[2];  // v,u,y,a
    src_ayuv += 4;
  }
}

// Convert UV plane of NV12 to VU of NV21.
void SwapUVRow_C(const uint8_t* src_uv, uint8_t* dst_vu, int width) {
  int x;
  for (x = 0; x < width; ++x) {
    uint8_t u = src_uv[0];
    uint8_t v = src_uv[1];
    dst_vu[0] = v;
    dst_vu[1] = u;
    src_uv += 2;
    dst_vu += 2;
  }
}

void HalfMergeUVRow_C(const uint8_t* src_u,
                      int src_stride_u,
                      const uint8_t* src_v,
                      int src_stride_v,
                      uint8_t* dst_uv,
                      int width) {
  int x;
  for (x = 0; x < width - 1; x += 2) {
    dst_uv[0] = (src_u[0] + src_u[1] + src_u[src_stride_u] +
                 src_u[src_stride_u + 1] + 2) >>
                2;
    dst_uv[1] = (src_v[0] + src_v[1] + src_v[src_stride_v] +
                 src_v[src_stride_v + 1] + 2) >>
                2;
    src_u += 2;
    src_v += 2;
    dst_uv += 2;
  }
  if (width & 1) {
    dst_uv[0] = (src_u[0] + src_u[src_stride_u] + 1) >> 1;
    dst_uv[1] = (src_v[0] + src_v[src_stride_v] + 1) >> 1;
  }
}

#ifdef __cplusplus
}  // extern "C"
}  // namespace libyuv
#endif