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 367
