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 "./vpx_dsp_rtcd.h"
18#include "test/acm_random.h"
19#include "vpx/vpx_integer.h"
20
21using libvpx_test::ACMRandom;
22
23namespace {
24
25#ifdef _MSC_VER
26static int round(double x) {
27  if (x < 0)
28    return static_cast<int>(ceil(x - 0.5));
29  else
30    return static_cast<int>(floor(x + 0.5));
31}
32#endif
33
34void reference_dct_1d(double input[8], double output[8]) {
35  const double kPi = 3.141592653589793238462643383279502884;
36  const double kInvSqrt2 = 0.707106781186547524400844362104;
37  for (int k = 0; k < 8; k++) {
38    output[k] = 0.0;
39    for (int n = 0; n < 8; n++)
40      output[k] += input[n]*cos(kPi*(2*n+1)*k/16.0);
41    if (k == 0)
42      output[k] = output[k]*kInvSqrt2;
43  }
44}
45
46void reference_dct_2d(int16_t input[64], double output[64]) {
47  // First transform columns
48  for (int i = 0; i < 8; ++i) {
49    double temp_in[8], temp_out[8];
50    for (int j = 0; j < 8; ++j)
51      temp_in[j] = input[j*8 + i];
52    reference_dct_1d(temp_in, temp_out);
53    for (int j = 0; j < 8; ++j)
54      output[j*8 + i] = temp_out[j];
55  }
56  // Then transform rows
57  for (int i = 0; i < 8; ++i) {
58    double temp_in[8], temp_out[8];
59    for (int j = 0; j < 8; ++j)
60      temp_in[j] = output[j + i*8];
61    reference_dct_1d(temp_in, temp_out);
62    for (int j = 0; j < 8; ++j)
63      output[j + i*8] = temp_out[j];
64  }
65  // Scale by some magic number
66  for (int i = 0; i < 64; ++i)
67    output[i] *= 2;
68}
69
70void reference_idct_1d(double input[8], double output[8]) {
71  const double kPi = 3.141592653589793238462643383279502884;
72  const double kSqrt2 = 1.414213562373095048801688724209698;
73  for (int k = 0; k < 8; k++) {
74    output[k] = 0.0;
75    for (int n = 0; n < 8; n++) {
76      output[k] += input[n]*cos(kPi*(2*k+1)*n/16.0);
77      if (n == 0)
78        output[k] = output[k]/kSqrt2;
79    }
80  }
81}
82
83void reference_idct_2d(double input[64], int16_t output[64]) {
84  double out[64], out2[64];
85  // First transform rows
86  for (int i = 0; i < 8; ++i) {
87    double temp_in[8], temp_out[8];
88    for (int j = 0; j < 8; ++j)
89      temp_in[j] = input[j + i*8];
90    reference_idct_1d(temp_in, temp_out);
91    for (int j = 0; j < 8; ++j)
92      out[j + i*8] = temp_out[j];
93  }
94  // Then transform columns
95  for (int i = 0; i < 8; ++i) {
96    double temp_in[8], temp_out[8];
97    for (int j = 0; j < 8; ++j)
98      temp_in[j] = out[j*8 + i];
99    reference_idct_1d(temp_in, temp_out);
100    for (int j = 0; j < 8; ++j)
101      out2[j*8 + i] = temp_out[j];
102  }
103  for (int i = 0; i < 64; ++i)
104    output[i] = round(out2[i]/32);
105}
106
107TEST(VP9Idct8x8Test, AccuracyCheck) {
108  ACMRandom rnd(ACMRandom::DeterministicSeed());
109  const int count_test_block = 10000;
110  for (int i = 0; i < count_test_block; ++i) {
111    int16_t input[64];
112    tran_low_t 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    vpx_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