path: root/files/unit_test/scale_test.cc

/*
 *  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 <stdlib.h>
#include <time.h>

#include "../unit_test/unit_test.h"
#include "libyuv/cpu_id.h"
#include "libyuv/scale.h"
#include "libyuv/scale_row.h"  // For ScaleRowDown2Box_Odd_C

#define STRINGIZE(line) #line
#define FILELINESTR(file, line) file ":" STRINGIZE(line)

namespace libyuv {

// Test scaling with C vs Opt and return maximum pixel difference. 0 = exact.
static int TestFilter(int src_width,
                      int src_height,
                      int dst_width,
                      int dst_height,
                      FilterMode f,
                      int benchmark_iterations,
                      int disable_cpu_flags,
                      int benchmark_cpu_info) {
  if (!SizeValid(src_width, src_height, dst_width, dst_height)) {
    return 0;
  }

  int i, j;
  int src_width_uv = (Abs(src_width) + 1) >> 1;
  int src_height_uv = (Abs(src_height) + 1) >> 1;

  int64_t src_y_plane_size = (Abs(src_width)) * (Abs(src_height));
  int64_t src_uv_plane_size = (src_width_uv) * (src_height_uv);

  int src_stride_y = Abs(src_width);
  int src_stride_uv = src_width_uv;

  align_buffer_page_end(src_y, src_y_plane_size);
  align_buffer_page_end(src_u, src_uv_plane_size);
  align_buffer_page_end(src_v, src_uv_plane_size);
  if (!src_y || !src_u || !src_v) {
    printf("Skipped.  Alloc failed " FILELINESTR(__FILE__, __LINE__) "\n");
    return 0;
  }
  MemRandomize(src_y, src_y_plane_size);
  MemRandomize(src_u, src_uv_plane_size);
  MemRandomize(src_v, src_uv_plane_size);

  int dst_width_uv = (dst_width + 1) >> 1;
  int dst_height_uv = (dst_height + 1) >> 1;

  int64_t dst_y_plane_size = (dst_width) * (dst_height);
  int64_t dst_uv_plane_size = (dst_width_uv) * (dst_height_uv);

  int dst_stride_y = dst_width;
  int dst_stride_uv = dst_width_uv;

  align_buffer_page_end(dst_y_c, dst_y_plane_size);
  align_buffer_page_end(dst_u_c, dst_uv_plane_size);
  align_buffer_page_end(dst_v_c, dst_uv_plane_size);
  align_buffer_page_end(dst_y_opt, dst_y_plane_size);
  align_buffer_page_end(dst_u_opt, dst_uv_plane_size);
  align_buffer_page_end(dst_v_opt, dst_uv_plane_size);
  if (!dst_y_c || !dst_u_c || !dst_v_c || !dst_y_opt || !dst_u_opt ||
      !dst_v_opt) {
    printf("Skipped.  Alloc failed " FILELINESTR(__FILE__, __LINE__) "\n");
    return 0;
  }

  MaskCpuFlags(disable_cpu_flags);  // Disable all CPU optimization.
  double c_time = get_time();
  I420Scale(src_y, src_stride_y, src_u, src_stride_uv, src_v, src_stride_uv,
            src_width, src_height, dst_y_c, dst_stride_y, dst_u_c,
            dst_stride_uv, dst_v_c, dst_stride_uv, dst_width, dst_height, f);
  c_time = (get_time() - c_time);

  MaskCpuFlags(benchmark_cpu_info);  // Enable all CPU optimization.
  double opt_time = get_time();
  for (i = 0; i < benchmark_iterations; ++i) {
    I420Scale(src_y, src_stride_y, src_u, src_stride_uv, src_v, src_stride_uv,
              src_width, src_height, dst_y_opt, dst_stride_y, dst_u_opt,
              dst_stride_uv, dst_v_opt, dst_stride_uv, dst_width, dst_height,
              f);
  }
  opt_time = (get_time() - opt_time) / benchmark_iterations;
  // Report performance of C vs OPT.
  printf("filter %d - %8d us C - %8d us OPT\n", f,
         static_cast<int>(c_time * 1e6), static_cast<int>(opt_time * 1e6));

  // C version may be a little off from the optimized. Order of
  //  operations may introduce rounding somewhere. So do a difference
  //  of the buffers and look to see that the max difference is not
  //  over 3.
  int max_diff = 0;
  for (i = 0; i < (dst_height); ++i) {
    for (j = 0; j < (dst_width); ++j) {
      int abs_diff = Abs(dst_y_c[(i * dst_stride_y) + j] -
                         dst_y_opt[(i * dst_stride_y) + j]);
      if (abs_diff > max_diff) {
        max_diff = abs_diff;
      }
    }
  }

  for (i = 0; i < (dst_height_uv); ++i) {
    for (j = 0; j < (dst_width_uv); ++j) {
      int abs_diff = Abs(dst_u_c[(i * dst_stride_uv) + j] -
                         dst_u_opt[(i * dst_stride_uv) + j]);
      if (abs_diff > max_diff) {
        max_diff = abs_diff;
      }
      abs_diff = Abs(dst_v_c[(i * dst_stride_uv) + j] -
                     dst_v_opt[(i * dst_stride_uv) + j]);
      if (abs_diff > max_diff) {
        max_diff = abs_diff;
      }
    }
  }

  free_aligned_buffer_page_end(dst_y_c);
  free_aligned_buffer_page_end(dst_u_c);
  free_aligned_buffer_page_end(dst_v_c);
  free_aligned_buffer_page_end(dst_y_opt);
  free_aligned_buffer_page_end(dst_u_opt);
  free_aligned_buffer_page_end(dst_v_opt);
  free_aligned_buffer_page_end(src_y);
  free_aligned_buffer_page_end(src_u);
  free_aligned_buffer_page_end(src_v);

  return max_diff;
}

// Test scaling with 8 bit C vs 16 bit C and return maximum pixel difference.
// 0 = exact.
static int TestFilter_16(int src_width,
                         int src_height,
                         int dst_width,
                         int dst_height,
                         FilterMode f,
                         int benchmark_iterations,
                         int disable_cpu_flags,
                         int benchmark_cpu_info) {
  if (!SizeValid(src_width, src_height, dst_width, dst_height)) {
    return 0;
  }

  int i;
  int src_width_uv = (Abs(src_width) + 1) >> 1;
  int src_height_uv = (Abs(src_height) + 1) >> 1;

  int64_t src_y_plane_size = (Abs(src_width)) * (Abs(src_height));
  int64_t src_uv_plane_size = (src_width_uv) * (src_height_uv);

  int src_stride_y = Abs(src_width);
  int src_stride_uv = src_width_uv;

  align_buffer_page_end(src_y, src_y_plane_size);
  align_buffer_page_end(src_u, src_uv_plane_size);
  align_buffer_page_end(src_v, src_uv_plane_size);
  align_buffer_page_end(src_y_16, src_y_plane_size * 2);
  align_buffer_page_end(src_u_16, src_uv_plane_size * 2);
  align_buffer_page_end(src_v_16, src_uv_plane_size * 2);
  if (!src_y || !src_u || !src_v || !src_y_16 || !src_u_16 || !src_v_16) {
    printf("Skipped.  Alloc failed " FILELINESTR(__FILE__, __LINE__) "\n");
    return 0;
  }
  uint16_t* p_src_y_16 = reinterpret_cast<uint16_t*>(src_y_16);
  uint16_t* p_src_u_16 = reinterpret_cast<uint16_t*>(src_u_16);
  uint16_t* p_src_v_16 = reinterpret_cast<uint16_t*>(src_v_16);

  MemRandomize(src_y, src_y_plane_size);
  MemRandomize(src_u, src_uv_plane_size);
  MemRandomize(src_v, src_uv_plane_size);

  for (i = 0; i < src_y_plane_size; ++i) {
    p_src_y_16[i] = src_y[i];
  }
  for (i = 0; i < src_uv_plane_size; ++i) {
    p_src_u_16[i] = src_u[i];
    p_src_v_16[i] = src_v[i];
  }

  int dst_width_uv = (dst_width + 1) >> 1;
  int dst_height_uv = (dst_height + 1) >> 1;

  int dst_y_plane_size = (dst_width) * (dst_height);
  int dst_uv_plane_size = (dst_width_uv) * (dst_height_uv);

  int dst_stride_y = dst_width;
  int dst_stride_uv = dst_width_uv;

  align_buffer_page_end(dst_y_8, dst_y_plane_size);
  align_buffer_page_end(dst_u_8, dst_uv_plane_size);
  align_buffer_page_end(dst_v_8, dst_uv_plane_size);
  align_buffer_page_end(dst_y_16, dst_y_plane_size * 2);
  align_buffer_page_end(dst_u_16, dst_uv_plane_size * 2);
  align_buffer_page_end(dst_v_16, dst_uv_plane_size * 2);

  uint16_t* p_dst_y_16 = reinterpret_cast<uint16_t*>(dst_y_16);
  uint16_t* p_dst_u_16 = reinterpret_cast<uint16_t*>(dst_u_16);
  uint16_t* p_dst_v_16 = reinterpret_cast<uint16_t*>(dst_v_16);

  MaskCpuFlags(disable_cpu_flags);  // Disable all CPU optimization.
  I420Scale(src_y, src_stride_y, src_u, src_stride_uv, src_v, src_stride_uv,
            src_width, src_height, dst_y_8, dst_stride_y, dst_u_8,
            dst_stride_uv, dst_v_8, dst_stride_uv, dst_width, dst_height, f);
  MaskCpuFlags(benchmark_cpu_info);  // Enable all CPU optimization.
  for (i = 0; i < benchmark_iterations; ++i) {
    I420Scale_16(p_src_y_16, src_stride_y, p_src_u_16, src_stride_uv,
                 p_src_v_16, src_stride_uv, src_width, src_height, p_dst_y_16,
                 dst_stride_y, p_dst_u_16, dst_stride_uv, p_dst_v_16,
                 dst_stride_uv, dst_width, dst_height, f);
  }

  // Expect an exact match.
  int max_diff = 0;
  for (i = 0; i < dst_y_plane_size; ++i) {
    int abs_diff = Abs(dst_y_8[i] - p_dst_y_16[i]);
    if (abs_diff > max_diff) {
      max_diff = abs_diff;
    }
  }
  for (i = 0; i < dst_uv_plane_size; ++i) {
    int abs_diff = Abs(dst_u_8[i] - p_dst_u_16[i]);
    if (abs_diff > max_diff) {
      max_diff = abs_diff;
    }
    abs_diff = Abs(dst_v_8[i] - p_dst_v_16[i]);
    if (abs_diff > max_diff) {
      max_diff = abs_diff;
    }
  }

  free_aligned_buffer_page_end(dst_y_8);
  free_aligned_buffer_page_end(dst_u_8);
  free_aligned_buffer_page_end(dst_v_8);
  free_aligned_buffer_page_end(dst_y_16);
  free_aligned_buffer_page_end(dst_u_16);
  free_aligned_buffer_page_end(dst_v_16);
  free_aligned_buffer_page_end(src_y);
  free_aligned_buffer_page_end(src_u);
  free_aligned_buffer_page_end(src_v);
  free_aligned_buffer_page_end(src_y_16);
  free_aligned_buffer_page_end(src_u_16);
  free_aligned_buffer_page_end(src_v_16);

  return max_diff;
}

// The following adjustments in dimensions ensure the scale factor will be
// exactly achieved.
// 2 is chroma subsample.
#define DX(x, nom, denom) static_cast<int>(((Abs(x) / nom + 1) / 2) * nom * 2)
#define SX(x, nom, denom) static_cast<int>(((x / nom + 1) / 2) * denom * 2)

#define TEST_FACTOR1(name, filter, nom, denom, max_diff)                     \
  TEST_F(LibYUVScaleTest, ScaleDownBy##name##_##filter) {                    \
    int diff = TestFilter(                                                   \
        SX(benchmark_width_, nom, denom), SX(benchmark_height_, nom, denom), \
        DX(benchmark_width_, nom, denom), DX(benchmark_height_, nom, denom), \
        kFilter##filter, benchmark_iterations_, disable_cpu_flags_,          \
        benchmark_cpu_info_);                                                \
    EXPECT_LE(diff, max_diff);                                               \
  }                                                                          \
  TEST_F(LibYUVScaleTest, ScaleDownBy##name##_##filter##_16) {               \
    int diff = TestFilter_16(                                                \
        SX(benchmark_width_, nom, denom), SX(benchmark_height_, nom, denom), \
        DX(benchmark_width_, nom, denom), DX(benchmark_height_, nom, denom), \
        kFilter##filter, benchmark_iterations_, disable_cpu_flags_,          \
        benchmark_cpu_info_);                                                \
    EXPECT_LE(diff, max_diff);                                               \
  }

// Test a scale factor with all 4 filters.  Expect unfiltered to be exact, but
// filtering is different fixed point implementations for SSSE3, Neon and C.
#define TEST_FACTOR(name, nom, denom, boxdiff) \
  TEST_FACTOR1(name, None, nom, denom, 0)      \
  TEST_FACTOR1(name, Linear, nom, denom, 3)    \
  TEST_FACTOR1(name, Bilinear, nom, denom, 3)  \
  TEST_FACTOR1(name, Box, nom, denom, boxdiff)

TEST_FACTOR(2, 1, 2, 0)
TEST_FACTOR(4, 1, 4, 0)
TEST_FACTOR(8, 1, 8, 0)
TEST_FACTOR(3by4, 3, 4, 1)
TEST_FACTOR(3by8, 3, 8, 1)
TEST_FACTOR(3, 1, 3, 0)
#undef TEST_FACTOR1
#undef TEST_FACTOR
#undef SX
#undef DX

#define TEST_SCALETO1(name, width, height, filter, max_diff)                  \
  TEST_F(LibYUVScaleTest, name##To##width##x##height##_##filter) {            \
    int diff = TestFilter(benchmark_width_, benchmark_height_, width, height, \
                          kFilter##filter, benchmark_iterations_,             \
                          disable_cpu_flags_, benchmark_cpu_info_);           \
    EXPECT_LE(diff, max_diff);                                                \
  }                                                                           \
  TEST_F(LibYUVScaleTest, name##From##width##x##height##_##filter) {          \
    int diff = TestFilter(width, height, Abs(benchmark_width_),               \
                          Abs(benchmark_height_), kFilter##filter,            \
                          benchmark_iterations_, disable_cpu_flags_,          \
                          benchmark_cpu_info_);                               \
    EXPECT_LE(diff, max_diff);                                                \
  }                                                                           \
  TEST_F(LibYUVScaleTest, name##To##width##x##height##_##filter##_16) {       \
    int diff = TestFilter_16(benchmark_width_, benchmark_height_, width,      \
                             height, kFilter##filter, benchmark_iterations_,  \
                             disable_cpu_flags_, benchmark_cpu_info_);        \
    EXPECT_LE(diff, max_diff);                                                \
  }                                                                           \
  TEST_F(LibYUVScaleTest, name##From##width##x##height##_##filter##_16) {     \
    int diff = TestFilter_16(width, height, Abs(benchmark_width_),            \
                             Abs(benchmark_height_), kFilter##filter,         \
                             benchmark_iterations_, disable_cpu_flags_,       \
                             benchmark_cpu_info_);                            \
    EXPECT_LE(diff, max_diff);                                                \
  }

// Test scale to a specified size with all 4 filters.
#define TEST_SCALETO(name, width, height)         \
  TEST_SCALETO1(name, width, height, None, 0)     \
  TEST_SCALETO1(name, width, height, Linear, 3)   \
  TEST_SCALETO1(name, width, height, Bilinear, 3) \
  TEST_SCALETO1(name, width, height, Box, 3)

TEST_SCALETO(Scale, 1, 1)
TEST_SCALETO(Scale, 320, 240)
TEST_SCALETO(Scale, 569, 480)
TEST_SCALETO(Scale, 640, 360)
TEST_SCALETO(Scale, 1280, 720)
TEST_SCALETO(Scale, 1920, 1080)
#undef TEST_SCALETO1
#undef TEST_SCALETO

#ifdef HAS_SCALEROWDOWN2_SSSE3
TEST_F(LibYUVScaleTest, TestScaleRowDown2Box_Odd_SSSE3) {
  SIMD_ALIGNED(uint8_t orig_pixels[128 * 2]);
  SIMD_ALIGNED(uint8_t dst_pixels_opt[64]);
  SIMD_ALIGNED(uint8_t dst_pixels_c[64]);
  memset(orig_pixels, 0, sizeof(orig_pixels));
  memset(dst_pixels_opt, 0, sizeof(dst_pixels_opt));
  memset(dst_pixels_c, 0, sizeof(dst_pixels_c));

  int has_ssse3 = TestCpuFlag(kCpuHasSSSE3);
  if (!has_ssse3) {
    printf("Warning SSSE3 not detected; Skipping test.\n");
  } else {
    // TL.
    orig_pixels[0] = 255u;
    orig_pixels[1] = 0u;
    orig_pixels[128 + 0] = 0u;
    orig_pixels[128 + 1] = 0u;
    // TR.
    orig_pixels[2] = 0u;
    orig_pixels[3] = 100u;
    orig_pixels[128 + 2] = 0u;
    orig_pixels[128 + 3] = 0u;
    // BL.
    orig_pixels[4] = 0u;
    orig_pixels[5] = 0u;
    orig_pixels[128 + 4] = 50u;
    orig_pixels[128 + 5] = 0u;
    // BR.
    orig_pixels[6] = 0u;
    orig_pixels[7] = 0u;
    orig_pixels[128 + 6] = 0u;
    orig_pixels[128 + 7] = 20u;
    // Odd.
    orig_pixels[126] = 4u;
    orig_pixels[127] = 255u;
    orig_pixels[128 + 126] = 16u;
    orig_pixels[128 + 127] = 255u;

    // Test regular half size.
    ScaleRowDown2Box_C(orig_pixels, 128, dst_pixels_c, 64);

    EXPECT_EQ(64u, dst_pixels_c[0]);
    EXPECT_EQ(25u, dst_pixels_c[1]);
    EXPECT_EQ(13u, dst_pixels_c[2]);
    EXPECT_EQ(5u, dst_pixels_c[3]);
    EXPECT_EQ(0u, dst_pixels_c[4]);
    EXPECT_EQ(133u, dst_pixels_c[63]);

    // Test Odd width version - Last pixel is just 1 horizontal pixel.
    ScaleRowDown2Box_Odd_C(orig_pixels, 128, dst_pixels_c, 64);

    EXPECT_EQ(64u, dst_pixels_c[0]);
    EXPECT_EQ(25u, dst_pixels_c[1]);
    EXPECT_EQ(13u, dst_pixels_c[2]);
    EXPECT_EQ(5u, dst_pixels_c[3]);
    EXPECT_EQ(0u, dst_pixels_c[4]);
    EXPECT_EQ(10u, dst_pixels_c[63]);

    // Test one pixel less, should skip the last pixel.
    memset(dst_pixels_c, 0, sizeof(dst_pixels_c));
    ScaleRowDown2Box_Odd_C(orig_pixels, 128, dst_pixels_c, 63);

    EXPECT_EQ(64u, dst_pixels_c[0]);
    EXPECT_EQ(25u, dst_pixels_c[1]);
    EXPECT_EQ(13u, dst_pixels_c[2]);
    EXPECT_EQ(5u, dst_pixels_c[3]);
    EXPECT_EQ(0u, dst_pixels_c[4]);
    EXPECT_EQ(0u, dst_pixels_c[63]);

    // Test regular half size SSSE3.
    ScaleRowDown2Box_SSSE3(orig_pixels, 128, dst_pixels_opt, 64);

    EXPECT_EQ(64u, dst_pixels_opt[0]);
    EXPECT_EQ(25u, dst_pixels_opt[1]);
    EXPECT_EQ(13u, dst_pixels_opt[2]);
    EXPECT_EQ(5u, dst_pixels_opt[3]);
    EXPECT_EQ(0u, dst_pixels_opt[4]);
    EXPECT_EQ(133u, dst_pixels_opt[63]);

    // Compare C and SSSE3 match.
    ScaleRowDown2Box_Odd_C(orig_pixels, 128, dst_pixels_c, 64);
    ScaleRowDown2Box_Odd_SSSE3(orig_pixels, 128, dst_pixels_opt, 64);
    for (int i = 0; i < 64; ++i) {
      EXPECT_EQ(dst_pixels_c[i], dst_pixels_opt[i]);
    }
  }
}
#endif  // HAS_SCALEROWDOWN2_SSSE3

extern "C" void ScaleRowUp2_16_NEON(const uint16_t* src_ptr,
                                    ptrdiff_t src_stride,
                                    uint16_t* dst,
                                    int dst_width);
extern "C" void ScaleRowUp2_16_MMI(const uint16_t* src_ptr,
                                   ptrdiff_t src_stride,
                                   uint16_t* dst,
                                   int dst_width);
extern "C" void ScaleRowUp2_16_C(const uint16_t* src_ptr,
                                 ptrdiff_t src_stride,
                                 uint16_t* dst,
                                 int dst_width);

TEST_F(LibYUVScaleTest, TestScaleRowUp2_16) {
  SIMD_ALIGNED(uint16_t orig_pixels[640 * 2 + 1]);  // 2 rows + 1 pixel overrun.
  SIMD_ALIGNED(uint16_t dst_pixels_opt[1280]);
  SIMD_ALIGNED(uint16_t dst_pixels_c[1280]);

  memset(orig_pixels, 0, sizeof(orig_pixels));
  memset(dst_pixels_opt, 1, sizeof(dst_pixels_opt));
  memset(dst_pixels_c, 2, sizeof(dst_pixels_c));

  for (int i = 0; i < 640 * 2 + 1; ++i) {
    orig_pixels[i] = i;
  }
  ScaleRowUp2_16_C(&orig_pixels[0], 640, &dst_pixels_c[0], 1280);
  for (int i = 0; i < benchmark_pixels_div1280_; ++i) {
#if !defined(LIBYUV_DISABLE_NEON) && defined(__aarch64__)
    int has_neon = TestCpuFlag(kCpuHasNEON);
    if (has_neon) {
      ScaleRowUp2_16_NEON(&orig_pixels[0], 640, &dst_pixels_opt[0], 1280);
    } else {
      ScaleRowUp2_16_C(&orig_pixels[0], 640, &dst_pixels_opt[0], 1280);
    }
#elif !defined(LIBYUV_DISABLE_MMI) && defined(_MIPS_ARCH_LOONGSON3A)
    int has_mmi = TestCpuFlag(kCpuHasMMI);
    if (has_mmi) {
      ScaleRowUp2_16_MMI(&orig_pixels[0], 640, &dst_pixels_opt[0], 1280);
    } else {
      ScaleRowUp2_16_C(&orig_pixels[0], 640, &dst_pixels_opt[0], 1280);
    }
#else
    ScaleRowUp2_16_C(&orig_pixels[0], 640, &dst_pixels_opt[0], 1280);
#endif
  }

  for (int i = 0; i < 1280; ++i) {
    EXPECT_EQ(dst_pixels_c[i], dst_pixels_opt[i]);
  }
  EXPECT_EQ(dst_pixels_c[0], (0 * 9 + 1 * 3 + 640 * 3 + 641 * 1 + 8) / 16);
  EXPECT_EQ(dst_pixels_c[1279], 800);
}

extern "C" void ScaleRowDown2Box_16_NEON(const uint16_t* src_ptr,
                                         ptrdiff_t src_stride,
                                         uint16_t* dst,
                                         int dst_width);

TEST_F(LibYUVScaleTest, TestScaleRowDown2Box_16) {
  SIMD_ALIGNED(uint16_t orig_pixels[2560 * 2]);
  SIMD_ALIGNED(uint16_t dst_pixels_c[1280]);
  SIMD_ALIGNED(uint16_t dst_pixels_opt[1280]);

  memset(orig_pixels, 0, sizeof(orig_pixels));
  memset(dst_pixels_c, 1, sizeof(dst_pixels_c));
  memset(dst_pixels_opt, 2, sizeof(dst_pixels_opt));

  for (int i = 0; i < 2560 * 2; ++i) {
    orig_pixels[i] = i;
  }
  ScaleRowDown2Box_16_C(&orig_pixels[0], 2560, &dst_pixels_c[0], 1280);
  for (int i = 0; i < benchmark_pixels_div1280_; ++i) {
#if !defined(LIBYUV_DISABLE_NEON) && defined(__aarch64__)
    int has_neon = TestCpuFlag(kCpuHasNEON);
    if (has_neon) {
      ScaleRowDown2Box_16_NEON(&orig_pixels[0], 2560, &dst_pixels_opt[0], 1280);
    } else {
      ScaleRowDown2Box_16_C(&orig_pixels[0], 2560, &dst_pixels_opt[0], 1280);
    }
#else
    ScaleRowDown2Box_16_C(&orig_pixels[0], 2560, &dst_pixels_opt[0], 1280);
#endif
  }

  for (int i = 0; i < 1280; ++i) {
    EXPECT_EQ(dst_pixels_c[i], dst_pixels_opt[i]);
  }

  EXPECT_EQ(dst_pixels_c[0], (0 + 1 + 2560 + 2561 + 2) / 4);
  EXPECT_EQ(dst_pixels_c[1279], 3839);
}

// Test scaling plane with 8 bit C vs 16 bit C and return maximum pixel
// difference.
// 0 = exact.
static int TestPlaneFilter_16(int src_width,
                              int src_height,
                              int dst_width,
                              int dst_height,
                              FilterMode f,
                              int benchmark_iterations,
                              int disable_cpu_flags,
                              int benchmark_cpu_info) {
  if (!SizeValid(src_width, src_height, dst_width, dst_height)) {
    return 0;
  }

  int i;
  int64_t src_y_plane_size = (Abs(src_width)) * (Abs(src_height));
  int src_stride_y = Abs(src_width);
  int dst_y_plane_size = dst_width * dst_height;
  int dst_stride_y = dst_width;

  align_buffer_page_end(src_y, src_y_plane_size);
  align_buffer_page_end(src_y_16, src_y_plane_size * 2);
  align_buffer_page_end(dst_y_8, dst_y_plane_size);
  align_buffer_page_end(dst_y_16, dst_y_plane_size * 2);
  uint16_t* p_src_y_16 = reinterpret_cast<uint16_t*>(src_y_16);
  uint16_t* p_dst_y_16 = reinterpret_cast<uint16_t*>(dst_y_16);

  MemRandomize(src_y, src_y_plane_size);
  memset(dst_y_8, 0, dst_y_plane_size);
  memset(dst_y_16, 1, dst_y_plane_size * 2);

  for (i = 0; i < src_y_plane_size; ++i) {
    p_src_y_16[i] = src_y[i] & 255;
  }

  MaskCpuFlags(disable_cpu_flags);  // Disable all CPU optimization.
  ScalePlane(src_y, src_stride_y, src_width, src_height, dst_y_8, dst_stride_y,
             dst_width, dst_height, f);
  MaskCpuFlags(benchmark_cpu_info);  // Enable all CPU optimization.

  for (i = 0; i < benchmark_iterations; ++i) {
    ScalePlane_16(p_src_y_16, src_stride_y, src_width, src_height, p_dst_y_16,
                  dst_stride_y, dst_width, dst_height, f);
  }

  // Expect an exact match.
  int max_diff = 0;
  for (i = 0; i < dst_y_plane_size; ++i) {
    int abs_diff = Abs(dst_y_8[i] - p_dst_y_16[i]);
    if (abs_diff > max_diff) {
      max_diff = abs_diff;
    }
  }

  free_aligned_buffer_page_end(dst_y_8);
  free_aligned_buffer_page_end(dst_y_16);
  free_aligned_buffer_page_end(src_y);
  free_aligned_buffer_page_end(src_y_16);

  return max_diff;
}

// The following adjustments in dimensions ensure the scale factor will be
// exactly achieved.
// 2 is chroma subsample.
#define DX(x, nom, denom) static_cast<int>(((Abs(x) / nom + 1) / 2) * nom * 2)
#define SX(x, nom, denom) static_cast<int>(((x / nom + 1) / 2) * denom * 2)

#define TEST_FACTOR1(name, filter, nom, denom, max_diff)                     \
  TEST_F(LibYUVScaleTest, ScalePlaneDownBy##name##_##filter##_16) {          \
    int diff = TestPlaneFilter_16(                                           \
        SX(benchmark_width_, nom, denom), SX(benchmark_height_, nom, denom), \
        DX(benchmark_width_, nom, denom), DX(benchmark_height_, nom, denom), \
        kFilter##filter, benchmark_iterations_, disable_cpu_flags_,          \
        benchmark_cpu_info_);                                                \
    EXPECT_LE(diff, max_diff);                                               \
  }

// Test a scale factor with all 4 filters.  Expect unfiltered to be exact, but
// filtering is different fixed point implementations for SSSE3, Neon and C.
#define TEST_FACTOR(name, nom, denom, boxdiff)      \
  TEST_FACTOR1(name, None, nom, denom, 0)           \
  TEST_FACTOR1(name, Linear, nom, denom, boxdiff)   \
  TEST_FACTOR1(name, Bilinear, nom, denom, boxdiff) \
  TEST_FACTOR1(name, Box, nom, denom, boxdiff)

TEST_FACTOR(2, 1, 2, 0)
TEST_FACTOR(4, 1, 4, 0)
TEST_FACTOR(8, 1, 8, 0)
TEST_FACTOR(3by4, 3, 4, 1)
TEST_FACTOR(3by8, 3, 8, 1)
TEST_FACTOR(3, 1, 3, 0)
#undef TEST_FACTOR1
#undef TEST_FACTOR
#undef SX
#undef DX
}  // namespace libyuv