1/*
2 *  Copyright (c) 2014 The WebRTC 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 "webrtc/common_audio/lapped_transform.h"
12
13#include <algorithm>
14#include <cmath>
15#include <cstring>
16
17#include "testing/gtest/include/gtest/gtest.h"
18
19using std::complex;
20
21namespace {
22
23class NoopCallback : public webrtc::LappedTransform::Callback {
24 public:
25  NoopCallback() : block_num_(0) {}
26
27  virtual void ProcessAudioBlock(const complex<float>* const* in_block,
28                                 size_t in_channels,
29                                 size_t frames,
30                                 size_t out_channels,
31                                 complex<float>* const* out_block) {
32    RTC_CHECK_EQ(in_channels, out_channels);
33    for (size_t i = 0; i < out_channels; ++i) {
34      memcpy(out_block[i], in_block[i], sizeof(**in_block) * frames);
35    }
36    ++block_num_;
37  }
38
39  size_t block_num() {
40    return block_num_;
41  }
42
43 private:
44  size_t block_num_;
45};
46
47class FftCheckerCallback : public webrtc::LappedTransform::Callback {
48 public:
49  FftCheckerCallback() : block_num_(0) {}
50
51  virtual void ProcessAudioBlock(const complex<float>* const* in_block,
52                                 size_t in_channels,
53                                 size_t frames,
54                                 size_t out_channels,
55                                 complex<float>* const* out_block) {
56    RTC_CHECK_EQ(in_channels, out_channels);
57
58    size_t full_length = (frames - 1) * 2;
59    ++block_num_;
60
61    if (block_num_ > 0) {
62      ASSERT_NEAR(in_block[0][0].real(), static_cast<float>(full_length),
63                  1e-5f);
64      ASSERT_NEAR(in_block[0][0].imag(), 0.0f, 1e-5f);
65      for (size_t i = 1; i < frames; ++i) {
66        ASSERT_NEAR(in_block[0][i].real(), 0.0f, 1e-5f);
67        ASSERT_NEAR(in_block[0][i].imag(), 0.0f, 1e-5f);
68      }
69    }
70  }
71
72  size_t block_num() {
73    return block_num_;
74  }
75
76 private:
77  size_t block_num_;
78};
79
80void SetFloatArray(float value, int rows, int cols, float* const* array) {
81  for (int i = 0; i < rows; ++i) {
82    for (int j = 0; j < cols; ++j) {
83      array[i][j] = value;
84    }
85  }
86}
87
88}  // namespace
89
90namespace webrtc {
91
92TEST(LappedTransformTest, Windowless) {
93  const size_t kChannels = 3;
94  const size_t kChunkLength = 512;
95  const size_t kBlockLength = 64;
96  const size_t kShiftAmount = 64;
97  NoopCallback noop;
98
99  // Rectangular window.
100  float window[kBlockLength];
101  std::fill(window, &window[kBlockLength], 1.0f);
102
103  LappedTransform trans(kChannels, kChannels, kChunkLength, window,
104                        kBlockLength, kShiftAmount, &noop);
105  float in_buffer[kChannels][kChunkLength];
106  float* in_chunk[kChannels];
107  float out_buffer[kChannels][kChunkLength];
108  float* out_chunk[kChannels];
109
110  in_chunk[0] = in_buffer[0];
111  in_chunk[1] = in_buffer[1];
112  in_chunk[2] = in_buffer[2];
113  out_chunk[0] = out_buffer[0];
114  out_chunk[1] = out_buffer[1];
115  out_chunk[2] = out_buffer[2];
116  SetFloatArray(2.0f, kChannels, kChunkLength, in_chunk);
117  SetFloatArray(-1.0f, kChannels, kChunkLength, out_chunk);
118
119  trans.ProcessChunk(in_chunk, out_chunk);
120
121  for (size_t i = 0; i < kChannels; ++i) {
122    for (size_t j = 0; j < kChunkLength; ++j) {
123      ASSERT_NEAR(out_chunk[i][j], 2.0f, 1e-5f);
124    }
125  }
126
127  ASSERT_EQ(kChunkLength / kBlockLength, noop.block_num());
128}
129
130TEST(LappedTransformTest, IdentityProcessor) {
131  const size_t kChunkLength = 512;
132  const size_t kBlockLength = 64;
133  const size_t kShiftAmount = 32;
134  NoopCallback noop;
135
136  // Identity window for |overlap = block_size / 2|.
137  float window[kBlockLength];
138  std::fill(window, &window[kBlockLength], std::sqrt(0.5f));
139
140  LappedTransform trans(1, 1, kChunkLength, window, kBlockLength, kShiftAmount,
141                        &noop);
142  float in_buffer[kChunkLength];
143  float* in_chunk = in_buffer;
144  float out_buffer[kChunkLength];
145  float* out_chunk = out_buffer;
146
147  SetFloatArray(2.0f, 1, kChunkLength, &in_chunk);
148  SetFloatArray(-1.0f, 1, kChunkLength, &out_chunk);
149
150  trans.ProcessChunk(&in_chunk, &out_chunk);
151
152  for (size_t i = 0; i < kChunkLength; ++i) {
153    ASSERT_NEAR(out_chunk[i],
154                (i < kBlockLength - kShiftAmount) ? 0.0f : 2.0f,
155                1e-5f);
156  }
157
158  ASSERT_EQ(kChunkLength / kShiftAmount, noop.block_num());
159}
160
161TEST(LappedTransformTest, Callbacks) {
162  const size_t kChunkLength = 512;
163  const size_t kBlockLength = 64;
164  FftCheckerCallback call;
165
166  // Rectangular window.
167  float window[kBlockLength];
168  std::fill(window, &window[kBlockLength], 1.0f);
169
170  LappedTransform trans(1, 1, kChunkLength, window, kBlockLength,
171                        kBlockLength, &call);
172  float in_buffer[kChunkLength];
173  float* in_chunk = in_buffer;
174  float out_buffer[kChunkLength];
175  float* out_chunk = out_buffer;
176
177  SetFloatArray(1.0f, 1, kChunkLength, &in_chunk);
178  SetFloatArray(-1.0f, 1, kChunkLength, &out_chunk);
179
180  trans.ProcessChunk(&in_chunk, &out_chunk);
181
182  ASSERT_EQ(kChunkLength / kBlockLength, call.block_num());
183}
184
185TEST(LappedTransformTest, chunk_length) {
186  const size_t kBlockLength = 64;
187  FftCheckerCallback call;
188  const float window[kBlockLength] = {};
189
190  // Make sure that chunk_length returns the same value passed to the
191  // LappedTransform constructor.
192  {
193    const size_t kExpectedChunkLength = 512;
194    const LappedTransform trans(1, 1, kExpectedChunkLength, window,
195                                kBlockLength, kBlockLength, &call);
196
197    EXPECT_EQ(kExpectedChunkLength, trans.chunk_length());
198  }
199  {
200    const size_t kExpectedChunkLength = 160;
201    const LappedTransform trans(1, 1, kExpectedChunkLength, window,
202                                kBlockLength, kBlockLength, &call);
203
204    EXPECT_EQ(kExpectedChunkLength, trans.chunk_length());
205  }
206}
207
208}  // namespace webrtc
209