1/*
2 *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include <math.h>
12#include <stdlib.h>
13#include <string.h>
14
15#include "third_party/googletest/src/include/gtest/gtest.h"
16
17#include "./vp9_rtcd.h"
18
19#include "test/acm_random.h"
20#include "vpx/vpx_integer.h"
21
22using libvpx_test::ACMRandom;
23
24namespace {
25
26#ifdef _MSC_VER
27static int round(double x) {
28  if (x < 0)
29    return static_cast<int>(ceil(x - 0.5));
30  else
31    return static_cast<int>(floor(x + 0.5));
32}
33#endif
34
35void reference_dct_1d(double input[8], double output[8]) {
36  const double kPi = 3.141592653589793238462643383279502884;
37  const double kInvSqrt2 = 0.707106781186547524400844362104;
38  for (int k = 0; k < 8; k++) {
39    output[k] = 0.0;
40    for (int n = 0; n < 8; n++)
41      output[k] += input[n]*cos(kPi*(2*n+1)*k/16.0);
42    if (k == 0)
43      output[k] = output[k]*kInvSqrt2;
44  }
45}
46
47void reference_dct_2d(int16_t input[64], double output[64]) {
48  // First transform columns
49  for (int i = 0; i < 8; ++i) {
50    double temp_in[8], temp_out[8];
51    for (int j = 0; j < 8; ++j)
52      temp_in[j] = input[j*8 + i];
53    reference_dct_1d(temp_in, temp_out);
54    for (int j = 0; j < 8; ++j)
55      output[j*8 + i] = temp_out[j];
56  }
57  // Then transform rows
58  for (int i = 0; i < 8; ++i) {
59    double temp_in[8], temp_out[8];
60    for (int j = 0; j < 8; ++j)
61      temp_in[j] = output[j + i*8];
62    reference_dct_1d(temp_in, temp_out);
63    for (int j = 0; j < 8; ++j)
64      output[j + i*8] = temp_out[j];
65  }
66  // Scale by some magic number
67  for (int i = 0; i < 64; ++i)
68    output[i] *= 2;
69}
70
71void reference_idct_1d(double input[8], double output[8]) {
72  const double kPi = 3.141592653589793238462643383279502884;
73  const double kSqrt2 = 1.414213562373095048801688724209698;
74  for (int k = 0; k < 8; k++) {
75    output[k] = 0.0;
76    for (int n = 0; n < 8; n++) {
77      output[k] += input[n]*cos(kPi*(2*k+1)*n/16.0);
78      if (n == 0)
79        output[k] = output[k]/kSqrt2;
80    }
81  }
82}
83
84void reference_idct_2d(double input[64], int16_t output[64]) {
85  double out[64], out2[64];
86  // First transform rows
87  for (int i = 0; i < 8; ++i) {
88    double temp_in[8], temp_out[8];
89    for (int j = 0; j < 8; ++j)
90      temp_in[j] = input[j + i*8];
91    reference_idct_1d(temp_in, temp_out);
92    for (int j = 0; j < 8; ++j)
93      out[j + i*8] = temp_out[j];
94  }
95  // Then transform columns
96  for (int i = 0; i < 8; ++i) {
97    double temp_in[8], temp_out[8];
98    for (int j = 0; j < 8; ++j)
99      temp_in[j] = out[j*8 + i];
100    reference_idct_1d(temp_in, temp_out);
101    for (int j = 0; j < 8; ++j)
102      out2[j*8 + i] = temp_out[j];
103  }
104  for (int i = 0; i < 64; ++i)
105    output[i] = round(out2[i]/32);
106}
107
108TEST(VP9Idct8x8Test, AccuracyCheck) {
109  ACMRandom rnd(ACMRandom::DeterministicSeed());
110  const int count_test_block = 10000;
111  for (int i = 0; i < count_test_block; ++i) {
112    int16_t input[64], coeff[64];
113    double output_r[64];
114    uint8_t dst[64], src[64];
115
116    for (int j = 0; j < 64; ++j) {
117      src[j] = rnd.Rand8();
118      dst[j] = rnd.Rand8();
119    }
120    // Initialize a test block with input range [-255, 255].
121    for (int j = 0; j < 64; ++j)
122      input[j] = src[j] - dst[j];
123
124    reference_dct_2d(input, output_r);
125    for (int j = 0; j < 64; ++j)
126      coeff[j] = round(output_r[j]);
127    vp9_idct8x8_64_add_c(coeff, dst, 8);
128    for (int j = 0; j < 64; ++j) {
129      const int diff = dst[j] - src[j];
130      const int error = diff * diff;
131      EXPECT_GE(1, error)
132          << "Error: 8x8 FDCT/IDCT has error " << error
133          << " at index " << j;
134    }
135  }
136}
137
138}  // namespace
139