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

#include "../unit_test/unit_test.h"
#include "libyuv/basic_types.h"
#include "libyuv/compare.h"
#include "libyuv/compare_row.h" /* For HammingDistance_C */
#include "libyuv/cpu_id.h"
#include "libyuv/video_common.h"

namespace libyuv {

// hash seed of 5381 recommended.
static uint32_t ReferenceHashDjb2(const uint8_t* src,
                                  uint64_t count,
                                  uint32_t seed) {
  uint32_t hash = seed;
  if (count > 0) {
    do {
      hash = hash * 33 + *src++;
    } while (--count);
  }
  return hash;
}

TEST_F(LibYUVCompareTest, Djb2_Test) {
  const int kMaxTest = benchmark_width_ * benchmark_height_;
  align_buffer_page_end(src_a, kMaxTest);
  align_buffer_page_end(src_b, kMaxTest);

  const char* fox =
      "The quick brown fox jumps over the lazy dog"
      " and feels as if he were in the seventh heaven of typography"
      " together with Hermann Zapf";
  uint32_t foxhash = HashDjb2(reinterpret_cast<const uint8_t*>(fox), 131, 5381);
  const uint32_t kExpectedFoxHash = 2611006483u;
  EXPECT_EQ(kExpectedFoxHash, foxhash);

  for (int i = 0; i < kMaxTest; ++i) {
    src_a[i] = (fastrand() & 0xff);
    src_b[i] = (fastrand() & 0xff);
  }
  // Compare different buffers. Expect hash is different.
  uint32_t h1 = HashDjb2(src_a, kMaxTest, 5381);
  uint32_t h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_NE(h1, h2);

  // Make last half same. Expect hash is different.
  memcpy(src_a + kMaxTest / 2, src_b + kMaxTest / 2, kMaxTest / 2);
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_NE(h1, h2);

  // Make first half same. Expect hash is different.
  memcpy(src_a + kMaxTest / 2, src_a, kMaxTest / 2);
  memcpy(src_b + kMaxTest / 2, src_b, kMaxTest / 2);
  memcpy(src_a, src_b, kMaxTest / 2);
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_NE(h1, h2);

  // Make same. Expect hash is same.
  memcpy(src_a, src_b, kMaxTest);
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_EQ(h1, h2);

  // Mask seed different. Expect hash is different.
  memcpy(src_a, src_b, kMaxTest);
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 1234);
  EXPECT_NE(h1, h2);

  // Make one byte different in middle. Expect hash is different.
  memcpy(src_a, src_b, kMaxTest);
  ++src_b[kMaxTest / 2];
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_NE(h1, h2);

  // Make first byte different. Expect hash is different.
  memcpy(src_a, src_b, kMaxTest);
  ++src_b[0];
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_NE(h1, h2);

  // Make last byte different. Expect hash is different.
  memcpy(src_a, src_b, kMaxTest);
  ++src_b[kMaxTest - 1];
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_b, kMaxTest, 5381);
  EXPECT_NE(h1, h2);

  // Make a zeros. Test different lengths. Expect hash is different.
  memset(src_a, 0, kMaxTest);
  h1 = HashDjb2(src_a, kMaxTest, 5381);
  h2 = HashDjb2(src_a, kMaxTest / 2, 5381);
  EXPECT_NE(h1, h2);

  // Make a zeros and seed of zero. Test different lengths. Expect hash is same.
  memset(src_a, 0, kMaxTest);
  h1 = HashDjb2(src_a, kMaxTest, 0);
  h2 = HashDjb2(src_a, kMaxTest / 2, 0);
  EXPECT_EQ(h1, h2);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, BenchmarkDjb2_Opt) {
  const int kMaxTest = benchmark_width_ * benchmark_height_;
  align_buffer_page_end(src_a, kMaxTest);

  for (int i = 0; i < kMaxTest; ++i) {
    src_a[i] = i;
  }
  uint32_t h2 = ReferenceHashDjb2(src_a, kMaxTest, 5381);
  uint32_t h1;
  for (int i = 0; i < benchmark_iterations_; ++i) {
    h1 = HashDjb2(src_a, kMaxTest, 5381);
  }
  EXPECT_EQ(h1, h2);
  free_aligned_buffer_page_end(src_a);
}

TEST_F(LibYUVCompareTest, BenchmarkDjb2_Unaligned) {
  const int kMaxTest = benchmark_width_ * benchmark_height_;
  align_buffer_page_end(src_a, kMaxTest + 1);
  for (int i = 0; i < kMaxTest; ++i) {
    src_a[i + 1] = i;
  }
  uint32_t h2 = ReferenceHashDjb2(src_a + 1, kMaxTest, 5381);
  uint32_t h1;
  for (int i = 0; i < benchmark_iterations_; ++i) {
    h1 = HashDjb2(src_a + 1, kMaxTest, 5381);
  }
  EXPECT_EQ(h1, h2);
  free_aligned_buffer_page_end(src_a);
}

TEST_F(LibYUVCompareTest, BenchmarkARGBDetect_Opt) {
  uint32_t fourcc;
  const int kMaxTest = benchmark_width_ * benchmark_height_ * 4;
  align_buffer_page_end(src_a, kMaxTest);
  for (int i = 0; i < kMaxTest; ++i) {
    src_a[i] = 255;
  }

  src_a[0] = 0;
  fourcc = ARGBDetect(src_a, benchmark_width_ * 4, benchmark_width_,
                      benchmark_height_);
  EXPECT_EQ(static_cast<uint32_t>(libyuv::FOURCC_BGRA), fourcc);
  src_a[0] = 255;
  src_a[3] = 0;
  fourcc = ARGBDetect(src_a, benchmark_width_ * 4, benchmark_width_,
                      benchmark_height_);
  EXPECT_EQ(static_cast<uint32_t>(libyuv::FOURCC_ARGB), fourcc);
  src_a[3] = 255;

  for (int i = 0; i < benchmark_iterations_; ++i) {
    fourcc = ARGBDetect(src_a, benchmark_width_ * 4, benchmark_width_,
                        benchmark_height_);
  }
  EXPECT_EQ(0u, fourcc);

  free_aligned_buffer_page_end(src_a);
}

TEST_F(LibYUVCompareTest, BenchmarkARGBDetect_Unaligned) {
  uint32_t fourcc;
  const int kMaxTest = benchmark_width_ * benchmark_height_ * 4 + 1;
  align_buffer_page_end(src_a, kMaxTest);
  for (int i = 1; i < kMaxTest; ++i) {
    src_a[i] = 255;
  }

  src_a[0 + 1] = 0;
  fourcc = ARGBDetect(src_a + 1, benchmark_width_ * 4, benchmark_width_,
                      benchmark_height_);
  EXPECT_EQ(static_cast<uint32_t>(libyuv::FOURCC_BGRA), fourcc);
  src_a[0 + 1] = 255;
  src_a[3 + 1] = 0;
  fourcc = ARGBDetect(src_a + 1, benchmark_width_ * 4, benchmark_width_,
                      benchmark_height_);
  EXPECT_EQ(static_cast<uint32_t>(libyuv::FOURCC_ARGB), fourcc);
  src_a[3 + 1] = 255;

  for (int i = 0; i < benchmark_iterations_; ++i) {
    fourcc = ARGBDetect(src_a + 1, benchmark_width_ * 4, benchmark_width_,
                        benchmark_height_);
  }
  EXPECT_EQ(0u, fourcc);

  free_aligned_buffer_page_end(src_a);
}

TEST_F(LibYUVCompareTest, BenchmarkHammingDistance_Opt) {
  const int kMaxWidth = 4096 * 3;
  align_buffer_page_end(src_a, kMaxWidth);
  align_buffer_page_end(src_b, kMaxWidth);
  memset(src_a, 0, kMaxWidth);
  memset(src_b, 0, kMaxWidth);

  // Test known value
  memcpy(src_a, "test0123test4567", 16);
  memcpy(src_b, "tick0123tock4567", 16);
  uint32_t h1 = HammingDistance_C(src_a, src_b, 16);
  EXPECT_EQ(16u, h1);

  // Test C vs OPT on random buffer
  MemRandomize(src_a, kMaxWidth);
  MemRandomize(src_b, kMaxWidth);

  uint32_t h0 = HammingDistance_C(src_a, src_b, kMaxWidth);

  int count =
      benchmark_iterations_ *
      ((benchmark_width_ * benchmark_height_ + kMaxWidth - 1) / kMaxWidth);
  for (int i = 0; i < count; ++i) {
#if defined(HAS_HAMMINGDISTANCE_NEON)
    h1 = HammingDistance_NEON(src_a, src_b, kMaxWidth);
#elif defined(HAS_HAMMINGDISTANCE_AVX2)
    int has_avx2 = TestCpuFlag(kCpuHasAVX2);
    if (has_avx2) {
      h1 = HammingDistance_AVX2(src_a, src_b, kMaxWidth);
    } else {
      int has_sse42 = TestCpuFlag(kCpuHasSSE42);
      if (has_sse42) {
        h1 = HammingDistance_SSE42(src_a, src_b, kMaxWidth);
      } else {
        int has_ssse3 = TestCpuFlag(kCpuHasSSSE3);
        if (has_ssse3) {
          h1 = HammingDistance_SSSE3(src_a, src_b, kMaxWidth);
        } else {
          h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
        }
      }
    }
#elif defined(HAS_HAMMINGDISTANCE_SSE42)
    int has_sse42 = TestCpuFlag(kCpuHasSSE42);
    if (has_sse42) {
      h1 = HammingDistance_SSE42(src_a, src_b, kMaxWidth);
    } else {
      h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
    }
#else
    h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
#endif
  }
  EXPECT_EQ(h0, h1);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, BenchmarkHammingDistance_C) {
  const int kMaxWidth = 4096 * 3;
  align_buffer_page_end(src_a, kMaxWidth);
  align_buffer_page_end(src_b, kMaxWidth);
  memset(src_a, 0, kMaxWidth);
  memset(src_b, 0, kMaxWidth);

  // Test known value
  memcpy(src_a, "test0123test4567", 16);
  memcpy(src_b, "tick0123tock4567", 16);
  uint32_t h1 = HammingDistance_C(src_a, src_b, 16);
  EXPECT_EQ(16u, h1);

  // Test C vs OPT on random buffer
  MemRandomize(src_a, kMaxWidth);
  MemRandomize(src_b, kMaxWidth);

  uint32_t h0 = HammingDistance_C(src_a, src_b, kMaxWidth);

  int count =
      benchmark_iterations_ *
      ((benchmark_width_ * benchmark_height_ + kMaxWidth - 1) / kMaxWidth);
  for (int i = 0; i < count; ++i) {
    h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
  }

  EXPECT_EQ(h0, h1);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, BenchmarkHammingDistance) {
  const int kMaxWidth = 4096 * 3;
  align_buffer_page_end(src_a, kMaxWidth);
  align_buffer_page_end(src_b, kMaxWidth);
  memset(src_a, 0, kMaxWidth);
  memset(src_b, 0, kMaxWidth);

  memcpy(src_a, "test0123test4567", 16);
  memcpy(src_b, "tick0123tock4567", 16);
  uint64_t h1 = ComputeHammingDistance(src_a, src_b, 16);
  EXPECT_EQ(16u, h1);

  // Test C vs OPT on random buffer
  MemRandomize(src_a, kMaxWidth);
  MemRandomize(src_b, kMaxWidth);

  uint32_t h0 = HammingDistance_C(src_a, src_b, kMaxWidth);

  int count =
      benchmark_iterations_ *
      ((benchmark_width_ * benchmark_height_ + kMaxWidth - 1) / kMaxWidth);
  for (int i = 0; i < count; ++i) {
    h1 = ComputeHammingDistance(src_a, src_b, kMaxWidth);
  }

  EXPECT_EQ(h0, h1);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

// Tests low levels match reference C for specified size.
// The opt implementations have size limitations
// For NEON the counters are 16 bit so the shorts overflow after 65536 bytes.
// So doing one less iteration of the loop is the maximum.
#if defined(HAS_HAMMINGDISTANCE_NEON)
static const int kMaxOptCount = 65536 - 32;  // 65504
#else
static const int kMaxOptCount = (1 << (32 - 3)) - 64;  // 536870848
#endif

TEST_F(LibYUVCompareTest, TestHammingDistance_Opt) {
  uint32_t h1 = 0;
  const int kMaxWidth = (benchmark_width_ * benchmark_height_ + 31) & ~31;
  align_buffer_page_end(src_a, kMaxWidth);
  align_buffer_page_end(src_b, kMaxWidth);
  memset(src_a, 255u, kMaxWidth);
  memset(src_b, 0u, kMaxWidth);

  uint64_t h0 = ComputeHammingDistance(src_a, src_b, kMaxWidth);
  EXPECT_EQ(kMaxWidth * 8ULL, h0);

  for (int i = 0; i < benchmark_iterations_; ++i) {
#if defined(HAS_HAMMINGDISTANCE_NEON)
    h1 = HammingDistance_NEON(src_a, src_b, kMaxWidth);
#elif defined(HAS_HAMMINGDISTANCE_AVX2)
    int has_avx2 = TestCpuFlag(kCpuHasAVX2);
    if (has_avx2) {
      h1 = HammingDistance_AVX2(src_a, src_b, kMaxWidth);
    } else {
      int has_sse42 = TestCpuFlag(kCpuHasSSE42);
      if (has_sse42) {
        h1 = HammingDistance_SSE42(src_a, src_b, kMaxWidth);
      } else {
        int has_ssse3 = TestCpuFlag(kCpuHasSSSE3);
        if (has_ssse3) {
          h1 = HammingDistance_SSSE3(src_a, src_b, kMaxWidth);
        } else {
          h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
        }
      }
    }
#elif defined(HAS_HAMMINGDISTANCE_SSE42)
    int has_sse42 = TestCpuFlag(kCpuHasSSE42);
    if (has_sse42) {
      h1 = HammingDistance_SSE42(src_a, src_b, kMaxWidth);
    } else {
      h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
    }
#else
    h1 = HammingDistance_C(src_a, src_b, kMaxWidth);
#endif
  }

  // A large count will cause the low level to potentially overflow so the
  // result can not be expected to be correct.
  // TODO(fbarchard): Consider expecting the low 16 bits to match.
  if (kMaxWidth <= kMaxOptCount) {
    EXPECT_EQ(kMaxWidth * 8U, h1);
  } else {
    if (kMaxWidth * 8ULL != static_cast<uint64_t>(h1)) {
      printf(
          "warning - HammingDistance_Opt %u does not match %llu "
          "but length of %u is longer than guaranteed.\n",
          h1, kMaxWidth * 8ULL, kMaxWidth);
    } else {
      printf(
          "warning - HammingDistance_Opt %u matches but length of %u "
          "is longer than guaranteed.\n",
          h1, kMaxWidth);
    }
  }

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, TestHammingDistance) {
  align_buffer_page_end(src_a, benchmark_width_ * benchmark_height_);
  align_buffer_page_end(src_b, benchmark_width_ * benchmark_height_);
  memset(src_a, 255u, benchmark_width_ * benchmark_height_);
  memset(src_b, 0, benchmark_width_ * benchmark_height_);

  uint64_t h1 = 0;
  for (int i = 0; i < benchmark_iterations_; ++i) {
    h1 = ComputeHammingDistance(src_a, src_b,
                                benchmark_width_ * benchmark_height_);
  }
  EXPECT_EQ(benchmark_width_ * benchmark_height_ * 8ULL, h1);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, BenchmarkSumSquareError_Opt) {
  const int kMaxWidth = 4096 * 3;
  align_buffer_page_end(src_a, kMaxWidth);
  align_buffer_page_end(src_b, kMaxWidth);
  memset(src_a, 0, kMaxWidth);
  memset(src_b, 0, kMaxWidth);

  memcpy(src_a, "test0123test4567", 16);
  memcpy(src_b, "tick0123tock4567", 16);
  uint64_t h1 = ComputeSumSquareError(src_a, src_b, 16);
  EXPECT_EQ(790u, h1);

  for (int i = 0; i < kMaxWidth; ++i) {
    src_a[i] = i;
    src_b[i] = i;
  }
  memset(src_a, 0, kMaxWidth);
  memset(src_b, 0, kMaxWidth);

  int count =
      benchmark_iterations_ *
      ((benchmark_width_ * benchmark_height_ + kMaxWidth - 1) / kMaxWidth);
  for (int i = 0; i < count; ++i) {
    h1 = ComputeSumSquareError(src_a, src_b, kMaxWidth);
  }

  EXPECT_EQ(0u, h1);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, SumSquareError) {
  const int kMaxWidth = 4096 * 3;
  align_buffer_page_end(src_a, kMaxWidth);
  align_buffer_page_end(src_b, kMaxWidth);
  memset(src_a, 0, kMaxWidth);
  memset(src_b, 0, kMaxWidth);

  uint64_t err;
  err = ComputeSumSquareError(src_a, src_b, kMaxWidth);

  EXPECT_EQ(0u, err);

  memset(src_a, 1, kMaxWidth);
  err = ComputeSumSquareError(src_a, src_b, kMaxWidth);

  EXPECT_EQ(static_cast<int>(err), kMaxWidth);

  memset(src_a, 190, kMaxWidth);
  memset(src_b, 193, kMaxWidth);
  err = ComputeSumSquareError(src_a, src_b, kMaxWidth);

  EXPECT_EQ(static_cast<int>(err), kMaxWidth * 3 * 3);

  for (int i = 0; i < kMaxWidth; ++i) {
    src_a[i] = (fastrand() & 0xff);
    src_b[i] = (fastrand() & 0xff);
  }

  MaskCpuFlags(disable_cpu_flags_);
  uint64_t c_err = ComputeSumSquareError(src_a, src_b, kMaxWidth);

  MaskCpuFlags(benchmark_cpu_info_);
  uint64_t opt_err = ComputeSumSquareError(src_a, src_b, kMaxWidth);

  EXPECT_EQ(c_err, opt_err);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, BenchmarkPsnr_Opt) {
  align_buffer_page_end(src_a, benchmark_width_ * benchmark_height_);
  align_buffer_page_end(src_b, benchmark_width_ * benchmark_height_);
  for (int i = 0; i < benchmark_width_ * benchmark_height_; ++i) {
    src_a[i] = i;
    src_b[i] = i;
  }

  MaskCpuFlags(benchmark_cpu_info_);

  double opt_time = get_time();
  for (int i = 0; i < benchmark_iterations_; ++i) {
    CalcFramePsnr(src_a, benchmark_width_, src_b, benchmark_width_,
                  benchmark_width_, benchmark_height_);
  }

  opt_time = (get_time() - opt_time) / benchmark_iterations_;
  printf("BenchmarkPsnr_Opt - %8.2f us opt\n", opt_time * 1e6);

  EXPECT_EQ(0, 0);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, BenchmarkPsnr_Unaligned) {
  align_buffer_page_end(src_a, benchmark_width_ * benchmark_height_ + 1);
  align_buffer_page_end(src_b, benchmark_width_ * benchmark_height_);
  for (int i = 0; i < benchmark_width_ * benchmark_height_; ++i) {
    src_a[i + 1] = i;
    src_b[i] = i;
  }

  MaskCpuFlags(benchmark_cpu_info_);

  double opt_time = get_time();
  for (int i = 0; i < benchmark_iterations_; ++i) {
    CalcFramePsnr(src_a + 1, benchmark_width_, src_b, benchmark_width_,
                  benchmark_width_, benchmark_height_);
  }

  opt_time = (get_time() - opt_time) / benchmark_iterations_;
  printf("BenchmarkPsnr_Opt - %8.2f us opt\n", opt_time * 1e6);

  EXPECT_EQ(0, 0);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, Psnr) {
  const int kSrcWidth = benchmark_width_;
  const int kSrcHeight = benchmark_height_;
  const int b = 128;
  const int kSrcPlaneSize = (kSrcWidth + b * 2) * (kSrcHeight + b * 2);
  const int kSrcStride = 2 * b + kSrcWidth;
  align_buffer_page_end(src_a, kSrcPlaneSize);
  align_buffer_page_end(src_b, kSrcPlaneSize);
  memset(src_a, 0, kSrcPlaneSize);
  memset(src_b, 0, kSrcPlaneSize);

  double err;
  err = CalcFramePsnr(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  EXPECT_EQ(err, kMaxPsnr);

  memset(src_a, 255, kSrcPlaneSize);

  err = CalcFramePsnr(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  EXPECT_EQ(err, 0.0);

  memset(src_a, 1, kSrcPlaneSize);

  err = CalcFramePsnr(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  EXPECT_GT(err, 48.0);
  EXPECT_LT(err, 49.0);

  for (int i = 0; i < kSrcPlaneSize; ++i) {
    src_a[i] = i;
  }

  err = CalcFramePsnr(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  EXPECT_GT(err, 2.0);
  if (kSrcWidth * kSrcHeight >= 256) {
    EXPECT_LT(err, 6.0);
  }

  memset(src_a, 0, kSrcPlaneSize);
  memset(src_b, 0, kSrcPlaneSize);

  for (int i = b; i < (kSrcHeight + b); ++i) {
    for (int j = b; j < (kSrcWidth + b); ++j) {
      src_a[(i * kSrcStride) + j] = (fastrand() & 0xff);
      src_b[(i * kSrcStride) + j] = (fastrand() & 0xff);
    }
  }

  MaskCpuFlags(disable_cpu_flags_);
  double c_err, opt_err;

  c_err = CalcFramePsnr(src_a + kSrcStride * b + b, kSrcStride,
                        src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                        kSrcHeight);

  MaskCpuFlags(benchmark_cpu_info_);

  opt_err = CalcFramePsnr(src_a + kSrcStride * b + b, kSrcStride,
                          src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                          kSrcHeight);

  EXPECT_EQ(opt_err, c_err);

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, DISABLED_BenchmarkSsim_Opt) {
  align_buffer_page_end(src_a, benchmark_width_ * benchmark_height_);
  align_buffer_page_end(src_b, benchmark_width_ * benchmark_height_);
  for (int i = 0; i < benchmark_width_ * benchmark_height_; ++i) {
    src_a[i] = i;
    src_b[i] = i;
  }

  MaskCpuFlags(benchmark_cpu_info_);

  double opt_time = get_time();
  for (int i = 0; i < benchmark_iterations_; ++i) {
    CalcFrameSsim(src_a, benchmark_width_, src_b, benchmark_width_,
                  benchmark_width_, benchmark_height_);
  }

  opt_time = (get_time() - opt_time) / benchmark_iterations_;
  printf("BenchmarkSsim_Opt - %8.2f us opt\n", opt_time * 1e6);

  EXPECT_EQ(0, 0);  // Pass if we get this far.

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

TEST_F(LibYUVCompareTest, Ssim) {
  const int kSrcWidth = benchmark_width_;
  const int kSrcHeight = benchmark_height_;
  const int b = 128;
  const int kSrcPlaneSize = (kSrcWidth + b * 2) * (kSrcHeight + b * 2);
  const int kSrcStride = 2 * b + kSrcWidth;
  align_buffer_page_end(src_a, kSrcPlaneSize);
  align_buffer_page_end(src_b, kSrcPlaneSize);
  memset(src_a, 0, kSrcPlaneSize);
  memset(src_b, 0, kSrcPlaneSize);

  if (kSrcWidth <= 8 || kSrcHeight <= 8) {
    printf("warning - Ssim size too small.  Testing function executes.\n");
  }

  double err;
  err = CalcFrameSsim(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  if (kSrcWidth > 8 && kSrcHeight > 8) {
    EXPECT_EQ(err, 1.0);
  }

  memset(src_a, 255, kSrcPlaneSize);

  err = CalcFrameSsim(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  if (kSrcWidth > 8 && kSrcHeight > 8) {
    EXPECT_LT(err, 0.0001);
  }

  memset(src_a, 1, kSrcPlaneSize);

  err = CalcFrameSsim(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  if (kSrcWidth > 8 && kSrcHeight > 8) {
    EXPECT_GT(err, 0.0001);
    EXPECT_LT(err, 0.9);
  }

  for (int i = 0; i < kSrcPlaneSize; ++i) {
    src_a[i] = i;
  }

  err = CalcFrameSsim(src_a + kSrcStride * b + b, kSrcStride,
                      src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                      kSrcHeight);

  if (kSrcWidth > 8 && kSrcHeight > 8) {
    EXPECT_GT(err, 0.0);
    EXPECT_LT(err, 0.01);
  }

  for (int i = b; i < (kSrcHeight + b); ++i) {
    for (int j = b; j < (kSrcWidth + b); ++j) {
      src_a[(i * kSrcStride) + j] = (fastrand() & 0xff);
      src_b[(i * kSrcStride) + j] = (fastrand() & 0xff);
    }
  }

  MaskCpuFlags(disable_cpu_flags_);
  double c_err, opt_err;

  c_err = CalcFrameSsim(src_a + kSrcStride * b + b, kSrcStride,
                        src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                        kSrcHeight);

  MaskCpuFlags(benchmark_cpu_info_);

  opt_err = CalcFrameSsim(src_a + kSrcStride * b + b, kSrcStride,
                          src_b + kSrcStride * b + b, kSrcStride, kSrcWidth,
                          kSrcHeight);

  if (kSrcWidth > 8 && kSrcHeight > 8) {
    EXPECT_EQ(opt_err, c_err);
  }

  free_aligned_buffer_page_end(src_a);
  free_aligned_buffer_page_end(src_b);
}

}  // namespace libyuv