text: /*
   *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #include "modules/audio_processing/aec3/aec3_fft.h"
  
  #include <algorithm>
  
  #include "test/gmock.h"
  #include "test/gtest.h"
  
  namespace webrtc {
  
  #if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
  
  // Verifies that the check for non-null input in Fft works.
  TEST(Aec3Fft, NullFftInput) {
    Aec3Fft fft;
    FftData X;
    EXPECT_DEATH(fft.Fft(nullptr, &X), "");
  }
  
  // Verifies that the check for non-null input in Fft works.
  TEST(Aec3Fft, NullFftOutput) {
    Aec3Fft fft;
    std::array<float, kFftLength> x;
    EXPECT_DEATH(fft.Fft(&x, nullptr), "");
  }
  
  // Verifies that the check for non-null output in Ifft works.
  TEST(Aec3Fft, NullIfftOutput) {
    Aec3Fft fft;
    FftData X;
    EXPECT_DEATH(fft.Ifft(X, nullptr), "");
  }
  
  // Verifies that the check for non-null output in ZeroPaddedFft works.
  TEST(Aec3Fft, NullZeroPaddedFftOutput) {
    Aec3Fft fft;
    std::array<float, kFftLengthBy2> x;
    EXPECT_DEATH(fft.ZeroPaddedFft(x, Aec3Fft::Window::kRectangular, nullptr),
                 "");
  }
  
  // Verifies that the check for input length in ZeroPaddedFft works.
  TEST(Aec3Fft, ZeroPaddedFftWrongInputLength) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLengthBy2 - 1> x;
    EXPECT_DEATH(fft.ZeroPaddedFft(x, Aec3Fft::Window::kRectangular, &X), "");
  }
  
  // Verifies that the check for non-null output in PaddedFft works.
  TEST(Aec3Fft, NullPaddedFftOutput) {
    Aec3Fft fft;
    std::array<float, kFftLengthBy2> x;
    std::array<float, kFftLengthBy2> x_old;
    EXPECT_DEATH(fft.PaddedFft(x, x_old, nullptr), "");
  }
  
  // Verifies that the check for input length in PaddedFft works.
  TEST(Aec3Fft, PaddedFftWrongInputLength) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLengthBy2 - 1> x;
    std::array<float, kFftLengthBy2> x_old;
    EXPECT_DEATH(fft.PaddedFft(x, x_old, &X), "");
  }
  
  // Verifies that the check for length in the old value in PaddedFft works.
  TEST(Aec3Fft, PaddedFftWrongOldValuesLength) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLengthBy2> x;
    std::array<float, kFftLengthBy2 - 1> x_old;
    EXPECT_DEATH(fft.PaddedFft(x, x_old, &X), "");
  }
  
  #endif
  
  // Verifies that Fft works as intended.
  TEST(Aec3Fft, Fft) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLength> x;
    x.fill(0.f);
    fft.Fft(&x, &X);
    EXPECT_THAT(X.re, ::testing::Each(0.f));
    EXPECT_THAT(X.im, ::testing::Each(0.f));
  
    x.fill(0.f);
    x[0] = 1.f;
    fft.Fft(&x, &X);
    EXPECT_THAT(X.re, ::testing::Each(1.f));
    EXPECT_THAT(X.im, ::testing::Each(0.f));
  
    x.fill(1.f);
    fft.Fft(&x, &X);
    EXPECT_EQ(128.f, X.re[0]);
    std::for_each(X.re.begin() + 1, X.re.end(),
                  [](float a) { EXPECT_EQ(0.f, a); });
    EXPECT_THAT(X.im, ::testing::Each(0.f));
  }
  
  // Verifies that InverseFft works as intended.
  TEST(Aec3Fft, Ifft) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLength> x;
  
    X.re.fill(0.f);
    X.im.fill(0.f);
    fft.Ifft(X, &x);
    EXPECT_THAT(x, ::testing::Each(0.f));
  
    X.re.fill(1.f);
    X.im.fill(0.f);
    fft.Ifft(X, &x);
    EXPECT_EQ(64.f, x[0]);
    std::for_each(x.begin() + 1, x.end(), [](float a) { EXPECT_EQ(0.f, a); });
  
    X.re.fill(0.f);
    X.re[0] = 128;
    X.im.fill(0.f);
    fft.Ifft(X, &x);
    EXPECT_THAT(x, ::testing::Each(64.f));
  }
  
  // Verifies that InverseFft and Fft work as intended.
  TEST(Aec3Fft, FftAndIfft) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLength> x;
    std::array<float, kFftLength> x_ref;
  
    int v = 0;
    for (int k = 0; k < 20; ++k) {
      for (size_t j = 0; j < x.size(); ++j) {
        x[j] = v++;
        x_ref[j] = x[j] * 64.f;
      }
      fft.Fft(&x, &X);
      fft.Ifft(X, &x);
      for (size_t j = 0; j < x.size(); ++j) {
        EXPECT_NEAR(x_ref[j], x[j], 0.001f);
      }
    }
  }
  
  // Verifies that ZeroPaddedFft work as intended.
  TEST(Aec3Fft, ZeroPaddedFft) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLengthBy2> x_in;
    std::array<float, kFftLength> x_ref;
    std::array<float, kFftLength> x_out;
  
    int v = 0;
    x_ref.fill(0.f);
    for (int k = 0; k < 20; ++k) {
      for (size_t j = 0; j < x_in.size(); ++j) {
        x_in[j] = v++;
        x_ref[j + kFftLengthBy2] = x_in[j] * 64.f;
      }
      fft.ZeroPaddedFft(x_in, Aec3Fft::Window::kRectangular, &X);
      fft.Ifft(X, &x_out);
      for (size_t j = 0; j < x_out.size(); ++j) {
        EXPECT_NEAR(x_ref[j], x_out[j], 0.1f);
      }
    }
  }
  
  // Verifies that ZeroPaddedFft work as intended.
  TEST(Aec3Fft, PaddedFft) {
    Aec3Fft fft;
    FftData X;
    std::array<float, kFftLengthBy2> x_in;
    std::array<float, kFftLength> x_out;
    std::array<float, kFftLengthBy2> x_old;
    std::array<float, kFftLengthBy2> x_old_ref;
    std::array<float, kFftLength> x_ref;
  
    int v = 0;
    x_old.fill(0.f);
    for (int k = 0; k < 20; ++k) {
      for (size_t j = 0; j < x_in.size(); ++j) {
        x_in[j] = v++;
      }
  
      std::copy(x_old.begin(), x_old.end(), x_ref.begin());
      std::copy(x_in.begin(), x_in.end(), x_ref.begin() + kFftLengthBy2);
      std::copy(x_in.begin(), x_in.end(), x_old_ref.begin());
      std::for_each(x_ref.begin(), x_ref.end(), [](float& a) { a *= 64.f; });
  
      fft.PaddedFft(x_in, x_old, &X);
      std::copy(x_in.begin(), x_in.end(), x_old.begin());
      fft.Ifft(X, &x_out);
  
      for (size_t j = 0; j < x_out.size(); ++j) {
        EXPECT_NEAR(x_ref[j], x_out[j], 0.1f);
      }
  
      EXPECT_EQ(x_old_ref, x_old);
    }
  }
  
  }  // namespace webrtc
  