1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/cpu.h"
6#include "base/memory/scoped_ptr.h"
7#include "media/base/simd/convert_rgb_to_yuv.h"
8#include "testing/gtest/include/gtest/gtest.h"
9
10namespace {
11
12// Reference code that converts RGB pixels to YUV pixels.
13int ConvertRGBToY(const uint8* rgb) {
14  int y = 25 * rgb[0] + 129 * rgb[1] + 66 * rgb[2];
15  y = ((y + 128) >> 8) + 16;
16  return std::max(0, std::min(255, y));
17}
18
19int ConvertRGBToU(const uint8* rgb, int size) {
20  int u = 112 * rgb[0] - 74 * rgb[1] - 38 * rgb[2];
21  u = ((u + 128) >> 8) + 128;
22  return std::max(0, std::min(255, u));
23}
24
25int ConvertRGBToV(const uint8* rgb, int size) {
26  int v = -18 * rgb[0] - 94 * rgb[1] + 112 * rgb[2];
27  v = ((v + 128) >> 8) + 128;
28  return std::max(0, std::min(255, v));
29}
30
31}  // namespace
32
33// A side-by-side test that verifies our ASM functions that convert RGB pixels
34// to YUV pixels can output the expected results. This test converts RGB pixels
35// to YUV pixels with our ASM functions (which use SSE, SSE2, SSE3, and SSSE3)
36// and compare the output YUV pixels with the ones calculated with out reference
37// functions implemented in C++.
38TEST(YUVConvertTest, SideBySideRGB) {
39  // We skip this test on PCs which does not support SSE3 because this test
40  // needs it.
41  base::CPU cpu;
42  if (!cpu.has_ssse3())
43    return;
44
45  // This test checks a subset of all RGB values so this test does not take so
46  // long time.
47  const int kStep = 8;
48  const int kWidth = 256 / kStep;
49
50  for (int size = 3; size <= 4; ++size) {
51    // Create the output buffers.
52    scoped_ptr<uint8[]> rgb(new uint8[kWidth * size]);
53    scoped_ptr<uint8[]> y(new uint8[kWidth]);
54    scoped_ptr<uint8[]> u(new uint8[kWidth / 2]);
55    scoped_ptr<uint8[]> v(new uint8[kWidth / 2]);
56
57    // Choose the function that converts from RGB pixels to YUV ones.
58    void (*convert)(const uint8*, uint8*, uint8*, uint8*,
59                    int, int, int, int, int) = NULL;
60    if (size == 3)
61      convert = media::ConvertRGB24ToYUV_SSSE3;
62    else
63      convert = media::ConvertRGB32ToYUV_SSSE3;
64
65    int total_error = 0;
66    for (int r = 0; r < kWidth; ++r) {
67      for (int g = 0; g < kWidth; ++g) {
68
69        // Fill the input pixels.
70        for (int b = 0; b < kWidth; ++b) {
71          rgb[b * size + 0] = b * kStep;
72          rgb[b * size + 1] = g * kStep;
73          rgb[b * size + 2] = r * kStep;
74          if (size == 4)
75            rgb[b * size + 3] = 255;
76        }
77
78        // Convert the input RGB pixels to YUV ones.
79        convert(rgb.get(), y.get(), u.get(), v.get(), kWidth, 1, kWidth * size,
80                kWidth, kWidth / 2);
81
82        // Check the output Y pixels.
83        for (int i = 0; i < kWidth; ++i) {
84          const uint8* p = &rgb[i * size];
85          int error = ConvertRGBToY(p) - y[i];
86          total_error += error > 0 ? error : -error;
87        }
88
89        // Check the output U pixels.
90        for (int i = 0; i < kWidth / 2; ++i) {
91          const uint8* p = &rgb[i * 2 * size];
92          int error = ConvertRGBToU(p, size) - u[i];
93          total_error += error > 0 ? error : -error;
94        }
95
96        // Check the output V pixels.
97        for (int i = 0; i < kWidth / 2; ++i) {
98          const uint8* p = &rgb[i * 2 * size];
99          int error = ConvertRGBToV(p, size) - v[i];
100          total_error += error > 0 ? error : -error;
101        }
102      }
103    }
104
105    EXPECT_EQ(0, total_error);
106  }
107}
108