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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 
10 namespace {
11 
12 // Reference code that converts RGB pixels to YUV pixels.
ConvertRGBToY(const uint8 * rgb)13 int 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 
ConvertRGBToU(const uint8 * rgb,int size)19 int 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 
ConvertRGBToV(const uint8 * rgb,int size)25 int 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 // Assembly code confuses MemorySanitizer. Do not run it in MSan builds.
34 #if defined(MEMORY_SANITIZER)
35 #define MAYBE_SideBySideRGB DISABLED_SideBySideRGB
36 #else
37 #define MAYBE_SideBySideRGB SideBySideRGB
38 #endif
39 
40 // A side-by-side test that verifies our ASM functions that convert RGB pixels
41 // to YUV pixels can output the expected results. This test converts RGB pixels
42 // to YUV pixels with our ASM functions (which use SSE, SSE2, SSE3, and SSSE3)
43 // and compare the output YUV pixels with the ones calculated with out reference
44 // functions implemented in C++.
TEST(YUVConvertTest,MAYBE_SideBySideRGB)45 TEST(YUVConvertTest, MAYBE_SideBySideRGB) {
46   // We skip this test on PCs which does not support SSE3 because this test
47   // needs it.
48   base::CPU cpu;
49   if (!cpu.has_ssse3())
50     return;
51 
52   // This test checks a subset of all RGB values so this test does not take so
53   // long time.
54   const int kStep = 8;
55   const int kWidth = 256 / kStep;
56 
57   for (int size = 3; size <= 4; ++size) {
58     // Create the output buffers.
59     scoped_ptr<uint8[]> rgb(new uint8[kWidth * size]);
60     scoped_ptr<uint8[]> y(new uint8[kWidth]);
61     scoped_ptr<uint8[]> u(new uint8[kWidth / 2]);
62     scoped_ptr<uint8[]> v(new uint8[kWidth / 2]);
63 
64     // Choose the function that converts from RGB pixels to YUV ones.
65     void (*convert)(const uint8*, uint8*, uint8*, uint8*,
66                     int, int, int, int, int) = NULL;
67     if (size == 3)
68       convert = media::ConvertRGB24ToYUV_SSSE3;
69     else
70       convert = media::ConvertRGB32ToYUV_SSSE3;
71 
72     int total_error = 0;
73     for (int r = 0; r < kWidth; ++r) {
74       for (int g = 0; g < kWidth; ++g) {
75 
76         // Fill the input pixels.
77         for (int b = 0; b < kWidth; ++b) {
78           rgb[b * size + 0] = b * kStep;
79           rgb[b * size + 1] = g * kStep;
80           rgb[b * size + 2] = r * kStep;
81           if (size == 4)
82             rgb[b * size + 3] = 255;
83         }
84 
85         // Convert the input RGB pixels to YUV ones.
86         convert(rgb.get(), y.get(), u.get(), v.get(), kWidth, 1, kWidth * size,
87                 kWidth, kWidth / 2);
88 
89         // Check the output Y pixels.
90         for (int i = 0; i < kWidth; ++i) {
91           const uint8* p = &rgb[i * size];
92           int error = ConvertRGBToY(p) - y[i];
93           total_error += error > 0 ? error : -error;
94         }
95 
96         // Check the output U pixels.
97         for (int i = 0; i < kWidth / 2; ++i) {
98           const uint8* p = &rgb[i * 2 * size];
99           int error = ConvertRGBToU(p, size) - u[i];
100           total_error += error > 0 ? error : -error;
101         }
102 
103         // Check the output V pixels.
104         for (int i = 0; i < kWidth / 2; ++i) {
105           const uint8* p = &rgb[i * 2 * size];
106           int error = ConvertRGBToV(p, size) - v[i];
107           total_error += error > 0 ? error : -error;
108         }
109       }
110     }
111 
112     EXPECT_EQ(0, total_error);
113   }
114 }
115