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
17extern "C" {
18#include "./vp9_rtcd.h"
19}
20
21#include "test/acm_random.h"
22#include "vpx/vpx_integer.h"
23
24using libvpx_test::ACMRandom;
25
26namespace {
27
28#ifdef _MSC_VER
29static int round(double x) {
30  if (x < 0)
31    return static_cast<int>(ceil(x - 0.5));
32  else
33    return static_cast<int>(floor(x + 0.5));
34}
35#endif
36
37void reference_dct_1d(double input[8], double output[8]) {
38  const double kPi = 3.141592653589793238462643383279502884;
39  const double kInvSqrt2 = 0.707106781186547524400844362104;
40  for (int k = 0; k < 8; k++) {
41    output[k] = 0.0;
42    for (int n = 0; n < 8; n++)
43      output[k] += input[n]*cos(kPi*(2*n+1)*k/16.0);
44    if (k == 0)
45      output[k] = output[k]*kInvSqrt2;
46  }
47}
48
49void reference_dct_2d(int16_t input[64], double output[64]) {
50  // First transform columns
51  for (int i = 0; i < 8; ++i) {
52    double temp_in[8], temp_out[8];
53    for (int j = 0; j < 8; ++j)
54      temp_in[j] = input[j*8 + i];
55    reference_dct_1d(temp_in, temp_out);
56    for (int j = 0; j < 8; ++j)
57      output[j*8 + i] = temp_out[j];
58  }
59  // Then transform rows
60  for (int i = 0; i < 8; ++i) {
61    double temp_in[8], temp_out[8];
62    for (int j = 0; j < 8; ++j)
63      temp_in[j] = output[j + i*8];
64    reference_dct_1d(temp_in, temp_out);
65    for (int j = 0; j < 8; ++j)
66      output[j + i*8] = temp_out[j];
67  }
68  // Scale by some magic number
69  for (int i = 0; i < 64; ++i)
70    output[i] *= 2;
71}
72
73void reference_idct_1d(double input[8], double output[8]) {
74  const double kPi = 3.141592653589793238462643383279502884;
75  const double kSqrt2 = 1.414213562373095048801688724209698;
76  for (int k = 0; k < 8; k++) {
77    output[k] = 0.0;
78    for (int n = 0; n < 8; n++) {
79      output[k] += input[n]*cos(kPi*(2*k+1)*n/16.0);
80      if (n == 0)
81        output[k] = output[k]/kSqrt2;
82    }
83  }
84}
85
86void reference_idct_2d(double input[64], int16_t output[64]) {
87  double out[64], out2[64];
88  // First transform rows
89  for (int i = 0; i < 8; ++i) {
90    double temp_in[8], temp_out[8];
91    for (int j = 0; j < 8; ++j)
92      temp_in[j] = input[j + i*8];
93    reference_idct_1d(temp_in, temp_out);
94    for (int j = 0; j < 8; ++j)
95      out[j + i*8] = temp_out[j];
96  }
97  // Then transform columns
98  for (int i = 0; i < 8; ++i) {
99    double temp_in[8], temp_out[8];
100    for (int j = 0; j < 8; ++j)
101      temp_in[j] = out[j*8 + i];
102    reference_idct_1d(temp_in, temp_out);
103    for (int j = 0; j < 8; ++j)
104      out2[j*8 + i] = temp_out[j];
105  }
106  for (int i = 0; i < 64; ++i)
107    output[i] = round(out2[i]/32);
108}
109
110TEST(VP9Idct8x8Test, AccuracyCheck) {
111  ACMRandom rnd(ACMRandom::DeterministicSeed());
112  const int count_test_block = 10000;
113  for (int i = 0; i < count_test_block; ++i) {
114    int16_t input[64], coeff[64];
115    double output_r[64];
116    uint8_t dst[64], src[64];
117
118    for (int j = 0; j < 64; ++j) {
119      src[j] = rnd.Rand8();
120      dst[j] = rnd.Rand8();
121    }
122    // Initialize a test block with input range [-255, 255].
123    for (int j = 0; j < 64; ++j)
124      input[j] = src[j] - dst[j];
125
126    reference_dct_2d(input, output_r);
127    for (int j = 0; j < 64; ++j)
128      coeff[j] = round(output_r[j]);
129    vp9_short_idct8x8_add_c(coeff, dst, 8);
130    for (int j = 0; j < 64; ++j) {
131      const int diff = dst[j] - src[j];
132      const int error = diff * diff;
133      EXPECT_GE(1, error)
134          << "Error: 8x8 FDCT/IDCT has error " << error
135          << " at index " << j;
136    }
137  }
138}
139
140}  // namespace
141