media/base/sinc_resampler_unittest.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // MSVC++ requires this to be set before any other includes to get M_PI.
   6 #define _USE_MATH_DEFINES
   7
   8 #include <cmath>
   9
  10 #include "base/bind.h"
  11 #include "base/bind_helpers.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/time/time.h"
  14 #include "build/build_config.h"
  15 #include "media/base/sinc_resampler.h"
  16 #include "testing/gmock/include/gmock/gmock.h"
  17 #include "testing/gtest/include/gtest/gtest.h"
  18
  19 using testing::_;
  20
  21 namespace media {
  22
  23 static const double kSampleRateRatio = 192000.0 / 44100.0;
  24
  25 // Helper class to ensure ChunkedResample() functions properly.
  26 class MockSource {
  27  public:
  28   MOCK_METHOD2(ProvideInput, void(int frames, float* destination));
  29 };
  30
  31 ACTION(ClearBuffer) {
  32   memset(arg1, 0, arg0 * sizeof(float));
  33 }
  34
  35 ACTION(FillBuffer) {
  36   // Value chosen arbitrarily such that SincResampler resamples it to something
  37   // easily representable on all platforms; e.g., using kSampleRateRatio this
  38   // becomes 1.81219.
  39   memset(arg1, 64, arg0 * sizeof(float));
  40 }
  41
  42 // Test requesting multiples of ChunkSize() frames results in the proper number
  43 // of callbacks.
  44 TEST(SincResamplerTest, ChunkedResample) {
  45   MockSource mock_source;
  46
  47   // Choose a high ratio of input to output samples which will result in quick
  48   // exhaustion of SincResampler's internal buffers.
  49   SincResampler resampler(
  50       kSampleRateRatio, SincResampler::kDefaultRequestSize,
  51       base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
  52
  53   static const int kChunks = 2;
  54   int max_chunk_size = resampler.ChunkSize() * kChunks;
  55   scoped_ptr<float[]> resampled_destination(new float[max_chunk_size]);
  56
  57   // Verify requesting ChunkSize() frames causes a single callback.
  58   EXPECT_CALL(mock_source, ProvideInput(_, _))
  59       .Times(1).WillOnce(ClearBuffer());
  60   resampler.Resample(resampler.ChunkSize(), resampled_destination.get());
  61
  62   // Verify requesting kChunks * ChunkSize() frames causes kChunks callbacks.
  63   testing::Mock::VerifyAndClear(&mock_source);
  64   EXPECT_CALL(mock_source, ProvideInput(_, _))
  65       .Times(kChunks).WillRepeatedly(ClearBuffer());
  66   resampler.Resample(max_chunk_size, resampled_destination.get());
  67 }
  68
  69 // Test flush resets the internal state properly.
  70 TEST(SincResamplerTest, Flush) {
  71   MockSource mock_source;
  72   SincResampler resampler(
  73       kSampleRateRatio, SincResampler::kDefaultRequestSize,
  74       base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
  75   scoped_ptr<float[]> resampled_destination(new float[resampler.ChunkSize()]);
  76
  77   // Fill the resampler with junk data.
  78   EXPECT_CALL(mock_source, ProvideInput(_, _))
  79       .Times(1).WillOnce(FillBuffer());
  80   resampler.Resample(resampler.ChunkSize() / 2, resampled_destination.get());
  81   ASSERT_NE(resampled_destination[0], 0);
  82
  83   // Flush and request more data, which should all be zeros now.
  84   resampler.Flush();
  85   testing::Mock::VerifyAndClear(&mock_source);
  86   EXPECT_CALL(mock_source, ProvideInput(_, _))
  87       .Times(1).WillOnce(ClearBuffer());
  88   resampler.Resample(resampler.ChunkSize() / 2, resampled_destination.get());
  89   for (int i = 0; i < resampler.ChunkSize() / 2; ++i)
  90     ASSERT_FLOAT_EQ(resampled_destination[i], 0);
  91 }
  92
  93 // Test flush resets the internal state properly.
  94 TEST(SincResamplerTest, DISABLED_SetRatioBench) {
  95   MockSource mock_source;
  96   SincResampler resampler(
  97       kSampleRateRatio, SincResampler::kDefaultRequestSize,
  98       base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
  99
 100   base::TimeTicks start = base::TimeTicks::HighResNow();
 101   for (int i = 1; i < 10000; ++i)
 102     resampler.SetRatio(1.0 / i);
 103   double total_time_c_ms =
 104       (base::TimeTicks::HighResNow() - start).InMillisecondsF();
 105   printf("SetRatio() took %.2fms.\n", total_time_c_ms);
 106 }
 107
 108
 109 // Define platform independent function name for Convolve* tests.
 110 #if defined(ARCH_CPU_X86_FAMILY)
 111 #define CONVOLVE_FUNC Convolve_SSE
 112 #elif defined(ARCH_CPU_ARM_FAMILY) && defined(USE_NEON)
 113 #define CONVOLVE_FUNC Convolve_NEON
 114 #endif
 115
 116 // Ensure various optimized Convolve() methods return the same value.  Only run
 117 // this test if other optimized methods exist, otherwise the default Convolve()
 118 // will be tested by the parameterized SincResampler tests below.
 119 #if defined(CONVOLVE_FUNC)
 120 static const double kKernelInterpolationFactor = 0.5;
 121
 122 TEST(SincResamplerTest, Convolve) {
 123   // Initialize a dummy resampler.
 124   MockSource mock_source;
 125   SincResampler resampler(
 126       kSampleRateRatio, SincResampler::kDefaultRequestSize,
 127       base::Bind(&MockSource::ProvideInput, base::Unretained(&mock_source)));
 128
 129   // The optimized Convolve methods are slightly more precise than Convolve_C(),
 130   // so comparison must be done using an epsilon.
 131   static const double kEpsilon = 0.00000005;
 132
 133   // Use a kernel from SincResampler as input and kernel data, this has the
 134   // benefit of already being properly sized and aligned for Convolve_SSE().
 135   double result = resampler.Convolve_C(
 136       resampler.kernel_storage_.get(), resampler.kernel_storage_.get(),
 137       resampler.kernel_storage_.get(), kKernelInterpolationFactor);
 138   double result2 = resampler.CONVOLVE_FUNC(
 139       resampler.kernel_storage_.get(), resampler.kernel_storage_.get(),
 140       resampler.kernel_storage_.get(), kKernelInterpolationFactor);
 141   EXPECT_NEAR(result2, result, kEpsilon);
 142
 143   // Test Convolve() w/ unaligned input pointer.
 144   result = resampler.Convolve_C(
 145       resampler.kernel_storage_.get() + 1, resampler.kernel_storage_.get(),
 146       resampler.kernel_storage_.get(), kKernelInterpolationFactor);
 147   result2 = resampler.CONVOLVE_FUNC(
 148       resampler.kernel_storage_.get() + 1, resampler.kernel_storage_.get(),
 149       resampler.kernel_storage_.get(), kKernelInterpolationFactor);
 150   EXPECT_NEAR(result2, result, kEpsilon);
 151 }
 152 #endif
 153
 154 // Fake audio source for testing the resampler.  Generates a sinusoidal linear
 155 // chirp (http://en.wikipedia.org/wiki/Chirp) which can be tuned to stress the
 156 // resampler for the specific sample rate conversion being used.
 157 class SinusoidalLinearChirpSource {
 158  public:
 159   SinusoidalLinearChirpSource(int sample_rate,
 160                               int samples,
 161                               double max_frequency)
 162       : sample_rate_(sample_rate),
 163         total_samples_(samples),
 164         max_frequency_(max_frequency),
 165         current_index_(0) {
 166     // Chirp rate.
 167     double duration = static_cast<double>(total_samples_) / sample_rate_;
 168     k_ = (max_frequency_ - kMinFrequency) / duration;
 169   }
 170
 171   virtual ~SinusoidalLinearChirpSource() {}
 172
 173   void ProvideInput(int frames, float* destination) {
 174     for (int i = 0; i < frames; ++i, ++current_index_) {
 175       // Filter out frequencies higher than Nyquist.
 176       if (Frequency(current_index_) > 0.5 * sample_rate_) {
 177         destination[i] = 0;
 178       } else {
 179         // Calculate time in seconds.
 180         double t = static_cast<double>(current_index_) / sample_rate_;
 181
 182         // Sinusoidal linear chirp.
 183         destination[i] = sin(2 * M_PI * (kMinFrequency * t + (k_ / 2) * t * t));
 184       }
 185     }
 186   }
 187
 188   double Frequency(int position) {
 189     return kMinFrequency + position * (max_frequency_ - kMinFrequency)
 190         / total_samples_;
 191   }
 192
 193  private:
 194   enum {
 195     kMinFrequency = 5
 196   };
 197
 198   double sample_rate_;
 199   int total_samples_;
 200   double max_frequency_;
 201   double k_;
 202   int current_index_;
 203
 204   DISALLOW_COPY_AND_ASSIGN(SinusoidalLinearChirpSource);
 205 };
 206
 207 typedef std::tr1::tuple<int, int, double, double> SincResamplerTestData;
 208 class SincResamplerTest
 209     : public testing::TestWithParam<SincResamplerTestData> {
 210  public:
 211   SincResamplerTest()
 212       : input_rate_(std::tr1::get<0>(GetParam())),
 213         output_rate_(std::tr1::get<1>(GetParam())),
 214         rms_error_(std::tr1::get<2>(GetParam())),
 215         low_freq_error_(std::tr1::get<3>(GetParam())) {
 216   }
 217
 218   virtual ~SincResamplerTest() {}
 219
 220  protected:
 221   int input_rate_;
 222   int output_rate_;
 223   double rms_error_;
 224   double low_freq_error_;
 225 };
 226
 227 // Tests resampling using a given input and output sample rate.
 228 TEST_P(SincResamplerTest, Resample) {
 229   // Make comparisons using one second of data.
 230   static const double kTestDurationSecs = 1;
 231   int input_samples = kTestDurationSecs * input_rate_;
 232   int output_samples = kTestDurationSecs * output_rate_;
 233
 234   // Nyquist frequency for the input sampling rate.
 235   double input_nyquist_freq = 0.5 * input_rate_;
 236
 237   // Source for data to be resampled.
 238   SinusoidalLinearChirpSource resampler_source(
 239       input_rate_, input_samples, input_nyquist_freq);
 240
 241   const double io_ratio = input_rate_ / static_cast<double>(output_rate_);
 242   SincResampler resampler(
 243       io_ratio, SincResampler::kDefaultRequestSize,
 244       base::Bind(&SinusoidalLinearChirpSource::ProvideInput,
 245                  base::Unretained(&resampler_source)));
 246
 247   // Force an update to the sample rate ratio to ensure dyanmic sample rate
 248   // changes are working correctly.
 249   scoped_ptr<float[]> kernel(new float[SincResampler::kKernelStorageSize]);
 250   memcpy(kernel.get(), resampler.get_kernel_for_testing(),
 251          SincResampler::kKernelStorageSize);
 252   resampler.SetRatio(M_PI);
 253   ASSERT_NE(0, memcmp(kernel.get(), resampler.get_kernel_for_testing(),
 254                       SincResampler::kKernelStorageSize));
 255   resampler.SetRatio(io_ratio);
 256   ASSERT_EQ(0, memcmp(kernel.get(), resampler.get_kernel_for_testing(),
 257                       SincResampler::kKernelStorageSize));
 258
 259   // TODO(dalecurtis): If we switch to AVX/SSE optimization, we'll need to
 260   // allocate these on 32-byte boundaries and ensure they're sized % 32 bytes.
 261   scoped_ptr<float[]> resampled_destination(new float[output_samples]);
 262   scoped_ptr<float[]> pure_destination(new float[output_samples]);
 263
 264   // Generate resampled signal.
 265   resampler.Resample(output_samples, resampled_destination.get());
 266
 267   // Generate pure signal.
 268   SinusoidalLinearChirpSource pure_source(
 269       output_rate_, output_samples, input_nyquist_freq);
 270   pure_source.ProvideInput(output_samples, pure_destination.get());
 271
 272   // Range of the Nyquist frequency (0.5 * min(input rate, output_rate)) which
 273   // we refer to as low and high.
 274   static const double kLowFrequencyNyquistRange = 0.7;
 275   static const double kHighFrequencyNyquistRange = 0.9;
 276
 277   // Calculate Root-Mean-Square-Error and maximum error for the resampling.
 278   double sum_of_squares = 0;
 279   double low_freq_max_error = 0;
 280   double high_freq_max_error = 0;
 281   int minimum_rate = std::min(input_rate_, output_rate_);
 282   double low_frequency_range = kLowFrequencyNyquistRange * 0.5 * minimum_rate;
 283   double high_frequency_range = kHighFrequencyNyquistRange * 0.5 * minimum_rate;
 284   for (int i = 0; i < output_samples; ++i) {
 285     double error = fabs(resampled_destination[i] - pure_destination[i]);
 286
 287     if (pure_source.Frequency(i) < low_frequency_range) {
 288       if (error > low_freq_max_error)
 289         low_freq_max_error = error;
 290     } else if (pure_source.Frequency(i) < high_frequency_range) {
 291       if (error > high_freq_max_error)
 292         high_freq_max_error = error;
 293     }
 294     // TODO(dalecurtis): Sanity check frequencies > kHighFrequencyNyquistRange.
 295
 296     sum_of_squares += error * error;
 297   }
 298
 299   double rms_error = sqrt(sum_of_squares / output_samples);
 300
 301   // Convert each error to dbFS.
 302   #define DBFS(x) 20 * log10(x)
 303   rms_error = DBFS(rms_error);
 304   low_freq_max_error = DBFS(low_freq_max_error);
 305   high_freq_max_error = DBFS(high_freq_max_error);
 306
 307   EXPECT_LE(rms_error, rms_error_);
 308   EXPECT_LE(low_freq_max_error, low_freq_error_);
 309
 310   // All conversions currently have a high frequency error around -6 dbFS.
 311   static const double kHighFrequencyMaxError = -6.02;
 312   EXPECT_LE(high_freq_max_error, kHighFrequencyMaxError);
 313 }
 314
 315 // Almost all conversions have an RMS error of around -14 dbFS.
 316 static const double kResamplingRMSError = -14.58;
 317
 318 // Thresholds chosen arbitrarily based on what each resampling reported during
 319 // testing.  All thresholds are in dbFS, http://en.wikipedia.org/wiki/DBFS.
 320 INSTANTIATE_TEST_CASE_P(
 321     SincResamplerTest, SincResamplerTest, testing::Values(
 322         // To 44.1kHz
 323         std::tr1::make_tuple(8000, 44100, kResamplingRMSError, -62.73),
 324         std::tr1::make_tuple(11025, 44100, kResamplingRMSError, -72.19),
 325         std::tr1::make_tuple(16000, 44100, kResamplingRMSError, -62.54),
 326         std::tr1::make_tuple(22050, 44100, kResamplingRMSError, -73.53),
 327         std::tr1::make_tuple(32000, 44100, kResamplingRMSError, -63.32),
 328         std::tr1::make_tuple(44100, 44100, kResamplingRMSError, -73.53),
 329         std::tr1::make_tuple(48000, 44100, -15.01, -64.04),
 330         std::tr1::make_tuple(96000, 44100, -18.49, -25.51),
 331         std::tr1::make_tuple(192000, 44100, -20.50, -13.31),
 332
 333         // To 48kHz
 334         std::tr1::make_tuple(8000, 48000, kResamplingRMSError, -63.43),
 335         std::tr1::make_tuple(11025, 48000, kResamplingRMSError, -62.61),
 336         std::tr1::make_tuple(16000, 48000, kResamplingRMSError, -63.96),
 337         std::tr1::make_tuple(22050, 48000, kResamplingRMSError, -62.42),
 338         std::tr1::make_tuple(32000, 48000, kResamplingRMSError, -64.04),
 339         std::tr1::make_tuple(44100, 48000, kResamplingRMSError, -62.63),
 340         std::tr1::make_tuple(48000, 48000, kResamplingRMSError, -73.52),
 341         std::tr1::make_tuple(96000, 48000, -18.40, -28.44),
 342         std::tr1::make_tuple(192000, 48000, -20.43, -14.11),
 343
 344         // To 96kHz
 345         std::tr1::make_tuple(8000, 96000, kResamplingRMSError, -63.19),
 346         std::tr1::make_tuple(11025, 96000, kResamplingRMSError, -62.61),
 347         std::tr1::make_tuple(16000, 96000, kResamplingRMSError, -63.39),
 348         std::tr1::make_tuple(22050, 96000, kResamplingRMSError, -62.42),
 349         std::tr1::make_tuple(32000, 96000, kResamplingRMSError, -63.95),
 350         std::tr1::make_tuple(44100, 96000, kResamplingRMSError, -62.63),
 351         std::tr1::make_tuple(48000, 96000, kResamplingRMSError, -73.52),
 352         std::tr1::make_tuple(96000, 96000, kResamplingRMSError, -73.52),
 353         std::tr1::make_tuple(192000, 96000, kResamplingRMSError, -28.41),
 354
 355         // To 192kHz
 356         std::tr1::make_tuple(8000, 192000, kResamplingRMSError, -63.10),
 357         std::tr1::make_tuple(11025, 192000, kResamplingRMSError, -62.61),
 358         std::tr1::make_tuple(16000, 192000, kResamplingRMSError, -63.14),
 359         std::tr1::make_tuple(22050, 192000, kResamplingRMSError, -62.42),
 360         std::tr1::make_tuple(32000, 192000, kResamplingRMSError, -63.38),
 361         std::tr1::make_tuple(44100, 192000, kResamplingRMSError, -62.63),
 362         std::tr1::make_tuple(48000, 192000, kResamplingRMSError, -73.44),
 363         std::tr1::make_tuple(96000, 192000, kResamplingRMSError, -73.52),
 364         std::tr1::make_tuple(192000, 192000, kResamplingRMSError, -73.52)));
 365
 366 }  // namespace media