2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
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.
13 #include "testing/gmock/include/gmock/gmock.h"
14 #include "testing/gtest/include/gtest/gtest.h"
15 #include "webrtc/common_audio/include/audio_util.h"
16 #include "webrtc/common_audio/resampler/push_sinc_resampler.h"
17 #include "webrtc/common_audio/resampler/sinusoidal_linear_chirp_source.h"
18 #include "webrtc/system_wrappers/interface/scoped_ptr.h"
19 #include "webrtc/system_wrappers/interface/tick_util.h"
20 #include "webrtc/typedefs.h"
24 typedef std::tr1::tuple<int, int, double, double> PushSincResamplerTestData;
25 class PushSincResamplerTest
26 : public testing::TestWithParam<PushSincResamplerTestData> {
28 PushSincResamplerTest()
29 : input_rate_(std::tr1::get<0>(GetParam())),
30 output_rate_(std::tr1::get<1>(GetParam())),
31 rms_error_(std::tr1::get<2>(GetParam())),
32 low_freq_error_(std::tr1::get<3>(GetParam())) {
35 virtual ~PushSincResamplerTest() {}
38 void ResampleBenchmarkTest(bool int_format);
39 void ResampleTest(bool int_format);
44 double low_freq_error_;
47 class ZeroSource : public SincResamplerCallback {
49 void Run(int frames, float* destination) {
50 memset(destination, 0, sizeof(float) * frames);
54 void PushSincResamplerTest::ResampleBenchmarkTest(bool int_format) {
55 const int input_samples = input_rate_ / 100;
56 const int output_samples = output_rate_ / 100;
57 const int kResampleIterations = 500000;
59 // Source for data to be resampled.
60 ZeroSource resampler_source;
62 scoped_ptr<float[]> resampled_destination(new float[output_samples]);
63 scoped_ptr<float[]> source(new float[input_samples]);
64 scoped_ptr<int16_t[]> source_int(new int16_t[input_samples]);
65 scoped_ptr<int16_t[]> destination_int(new int16_t[output_samples]);
67 resampler_source.Run(input_samples, source.get());
68 for (int i = 0; i < input_samples; ++i) {
69 source_int[i] = static_cast<int16_t>(floor(32767 * source[i] + 0.5));
72 printf("Benchmarking %d iterations of %d Hz -> %d Hz:\n",
73 kResampleIterations, input_rate_, output_rate_);
74 const double io_ratio = input_rate_ / static_cast<double>(output_rate_);
75 SincResampler sinc_resampler(io_ratio, SincResampler::kDefaultRequestSize,
77 TickTime start = TickTime::Now();
78 for (int i = 0; i < kResampleIterations; ++i) {
79 sinc_resampler.Resample(output_samples, resampled_destination.get());
81 double total_time_sinc_us = (TickTime::Now() - start).Microseconds();
82 printf("SincResampler took %.2f us per frame.\n",
83 total_time_sinc_us / kResampleIterations);
85 PushSincResampler resampler(input_samples, output_samples);
86 start = TickTime::Now();
88 for (int i = 0; i < kResampleIterations; ++i) {
89 EXPECT_EQ(output_samples,
90 resampler.Resample(source_int.get(),
92 destination_int.get(),
96 for (int i = 0; i < kResampleIterations; ++i) {
97 EXPECT_EQ(output_samples,
98 resampler.Resample(source.get(),
100 resampled_destination.get(),
104 double total_time_us = (TickTime::Now() - start).Microseconds();
105 printf("PushSincResampler took %.2f us per frame; which is a %.1f%% overhead "
106 "on SincResampler.\n\n", total_time_us / kResampleIterations,
107 (total_time_us - total_time_sinc_us) / total_time_sinc_us * 100);
110 // Disabled because it takes too long to run routinely. Use for performance
111 // benchmarking when needed.
112 TEST_P(PushSincResamplerTest, DISABLED_BenchmarkInt) {
113 ResampleBenchmarkTest(true);
116 TEST_P(PushSincResamplerTest, DISABLED_BenchmarkFloat) {
117 ResampleBenchmarkTest(false);
120 // Tests resampling using a given input and output sample rate.
121 void PushSincResamplerTest::ResampleTest(bool int_format) {
122 // Make comparisons using one second of data.
123 static const double kTestDurationSecs = 1;
125 const int kNumBlocks = kTestDurationSecs * 100;
126 const int input_block_size = input_rate_ / 100;
127 const int output_block_size = output_rate_ / 100;
128 const int input_samples = kTestDurationSecs * input_rate_;
129 const int output_samples = kTestDurationSecs * output_rate_;
131 // Nyquist frequency for the input sampling rate.
132 const double input_nyquist_freq = 0.5 * input_rate_;
134 // Source for data to be resampled.
135 SinusoidalLinearChirpSource resampler_source(
136 input_rate_, input_samples, input_nyquist_freq, 0);
138 PushSincResampler resampler(input_block_size, output_block_size);
140 // TODO(dalecurtis): If we switch to AVX/SSE optimization, we'll need to
141 // allocate these on 32-byte boundaries and ensure they're sized % 32 bytes.
142 scoped_ptr<float[]> resampled_destination(new float[output_samples]);
143 scoped_ptr<float[]> pure_destination(new float[output_samples]);
144 scoped_ptr<float[]> source(new float[input_samples]);
145 scoped_ptr<int16_t[]> source_int(new int16_t[input_block_size]);
146 scoped_ptr<int16_t[]> destination_int(new int16_t[output_block_size]);
148 // The sinc resampler has an implicit delay of approximately half the kernel
149 // size at the input sample rate. By moving to a push model, this delay
150 // becomes explicit and is managed by zero-stuffing in PushSincResampler. We
151 // deal with it in the test by delaying the "pure" source to match. It must be
152 // checked before the first call to Resample(), because ChunkSize() will
153 // change afterwards.
154 const int output_delay_samples = output_block_size -
155 resampler.get_resampler_for_testing()->ChunkSize();
157 // Generate resampled signal.
158 // With the PushSincResampler, we produce the signal block-by-10ms-block
159 // rather than in a single pass, to exercise how it will be used in WebRTC.
160 resampler_source.Run(input_samples, source.get());
162 for (int i = 0; i < kNumBlocks; ++i) {
163 ScaleAndRoundToInt16(
164 &source[i * input_block_size], input_block_size, source_int.get());
165 EXPECT_EQ(output_block_size,
166 resampler.Resample(source_int.get(),
168 destination_int.get(),
170 ScaleToFloat(destination_int.get(),
172 &resampled_destination[i * output_block_size]);
175 for (int i = 0; i < kNumBlocks; ++i) {
178 resampler.Resample(&source[i * input_block_size],
180 &resampled_destination[i * output_block_size],
185 // Generate pure signal.
186 SinusoidalLinearChirpSource pure_source(
187 output_rate_, output_samples, input_nyquist_freq, output_delay_samples);
188 pure_source.Run(output_samples, pure_destination.get());
190 // Range of the Nyquist frequency (0.5 * min(input rate, output_rate)) which
191 // we refer to as low and high.
192 static const double kLowFrequencyNyquistRange = 0.7;
193 static const double kHighFrequencyNyquistRange = 0.9;
195 // Calculate Root-Mean-Square-Error and maximum error for the resampling.
196 double sum_of_squares = 0;
197 double low_freq_max_error = 0;
198 double high_freq_max_error = 0;
199 int minimum_rate = std::min(input_rate_, output_rate_);
200 double low_frequency_range = kLowFrequencyNyquistRange * 0.5 * minimum_rate;
201 double high_frequency_range = kHighFrequencyNyquistRange * 0.5 * minimum_rate;
203 for (int i = 0; i < output_samples; ++i) {
204 double error = fabs(resampled_destination[i] - pure_destination[i]);
206 if (pure_source.Frequency(i) < low_frequency_range) {
207 if (error > low_freq_max_error)
208 low_freq_max_error = error;
209 } else if (pure_source.Frequency(i) < high_frequency_range) {
210 if (error > high_freq_max_error)
211 high_freq_max_error = error;
213 // TODO(dalecurtis): Sanity check frequencies > kHighFrequencyNyquistRange.
215 sum_of_squares += error * error;
218 double rms_error = sqrt(sum_of_squares / output_samples);
220 // Convert each error to dbFS.
221 #define DBFS(x) 20 * log10(x)
222 rms_error = DBFS(rms_error);
223 // In order to keep the thresholds in this test identical to SincResamplerTest
224 // we must account for the quantization error introduced by truncating from
225 // float to int. This happens twice (once at input and once at output) and we
226 // allow for the maximum possible error (1 / 32767) for each step.
228 // The quantization error is insignificant in the RMS calculation so does not
229 // need to be accounted for there.
230 low_freq_max_error = DBFS(low_freq_max_error - 2.0 / 32767);
231 high_freq_max_error = DBFS(high_freq_max_error - 2.0 / 32767);
233 EXPECT_LE(rms_error, rms_error_);
234 EXPECT_LE(low_freq_max_error, low_freq_error_);
236 // All conversions currently have a high frequency error around -6 dbFS.
237 static const double kHighFrequencyMaxError = -6.02;
238 EXPECT_LE(high_freq_max_error, kHighFrequencyMaxError);
241 TEST_P(PushSincResamplerTest, ResampleInt) { ResampleTest(true); }
243 TEST_P(PushSincResamplerTest, ResampleFloat) { ResampleTest(false); }
245 // Almost all conversions have an RMS error of around -14 dbFS.
246 static const double kResamplingRMSError = -14.42;
248 // Thresholds chosen arbitrarily based on what each resampling reported during
249 // testing. All thresholds are in dbFS, http://en.wikipedia.org/wiki/DBFS.
250 INSTANTIATE_TEST_CASE_P(
251 PushSincResamplerTest,
252 PushSincResamplerTest,
254 // First run through the rates tested in SincResamplerTest. The
255 // thresholds are identical.
257 // We don't test rates which fail to provide an integer number of
258 // samples in a 10 ms block (22050 and 11025 Hz). WebRTC doesn't support
259 // these rates in any case (for the same reason).
262 std::tr1::make_tuple(8000, 44100, kResamplingRMSError, -62.73),
263 std::tr1::make_tuple(16000, 44100, kResamplingRMSError, -62.54),
264 std::tr1::make_tuple(32000, 44100, kResamplingRMSError, -63.32),
265 std::tr1::make_tuple(44100, 44100, kResamplingRMSError, -73.53),
266 std::tr1::make_tuple(48000, 44100, -15.01, -64.04),
267 std::tr1::make_tuple(96000, 44100, -18.49, -25.51),
268 std::tr1::make_tuple(192000, 44100, -20.50, -13.31),
271 std::tr1::make_tuple(8000, 48000, kResamplingRMSError, -63.43),
272 std::tr1::make_tuple(16000, 48000, kResamplingRMSError, -63.96),
273 std::tr1::make_tuple(32000, 48000, kResamplingRMSError, -64.04),
274 std::tr1::make_tuple(44100, 48000, kResamplingRMSError, -62.63),
275 std::tr1::make_tuple(48000, 48000, kResamplingRMSError, -73.52),
276 std::tr1::make_tuple(96000, 48000, -18.40, -28.44),
277 std::tr1::make_tuple(192000, 48000, -20.43, -14.11),
280 std::tr1::make_tuple(8000, 96000, kResamplingRMSError, -63.19),
281 std::tr1::make_tuple(16000, 96000, kResamplingRMSError, -63.39),
282 std::tr1::make_tuple(32000, 96000, kResamplingRMSError, -63.95),
283 std::tr1::make_tuple(44100, 96000, kResamplingRMSError, -62.63),
284 std::tr1::make_tuple(48000, 96000, kResamplingRMSError, -73.52),
285 std::tr1::make_tuple(96000, 96000, kResamplingRMSError, -73.52),
286 std::tr1::make_tuple(192000, 96000, kResamplingRMSError, -28.41),
289 std::tr1::make_tuple(8000, 192000, kResamplingRMSError, -63.10),
290 std::tr1::make_tuple(16000, 192000, kResamplingRMSError, -63.14),
291 std::tr1::make_tuple(32000, 192000, kResamplingRMSError, -63.38),
292 std::tr1::make_tuple(44100, 192000, kResamplingRMSError, -62.63),
293 std::tr1::make_tuple(48000, 192000, kResamplingRMSError, -73.44),
294 std::tr1::make_tuple(96000, 192000, kResamplingRMSError, -73.52),
295 std::tr1::make_tuple(192000, 192000, kResamplingRMSError, -73.52),
297 // Next run through some additional cases interesting for WebRTC.
298 // We skip some extreme downsampled cases (192 -> {8, 16}, 96 -> 8)
299 // because they violate |kHighFrequencyMaxError|, which is not
300 // unexpected. It's very unlikely that we'll see these conversions in
304 std::tr1::make_tuple(8000, 8000, kResamplingRMSError, -75.50),
305 std::tr1::make_tuple(16000, 8000, -18.56, -28.79),
306 std::tr1::make_tuple(32000, 8000, -20.36, -14.13),
307 std::tr1::make_tuple(44100, 8000, -21.00, -11.39),
308 std::tr1::make_tuple(48000, 8000, -20.96, -11.04),
311 std::tr1::make_tuple(8000, 16000, kResamplingRMSError, -70.30),
312 std::tr1::make_tuple(16000, 16000, kResamplingRMSError, -75.51),
313 std::tr1::make_tuple(32000, 16000, -18.48, -28.59),
314 std::tr1::make_tuple(44100, 16000, -19.30, -19.67),
315 std::tr1::make_tuple(48000, 16000, -19.81, -18.11),
316 std::tr1::make_tuple(96000, 16000, -20.95, -10.96),
319 std::tr1::make_tuple(8000, 32000, kResamplingRMSError, -70.30),
320 std::tr1::make_tuple(16000, 32000, kResamplingRMSError, -75.51),
321 std::tr1::make_tuple(32000, 32000, kResamplingRMSError, -75.51),
322 std::tr1::make_tuple(44100, 32000, -16.44, -51.10),
323 std::tr1::make_tuple(48000, 32000, -16.90, -44.03),
324 std::tr1::make_tuple(96000, 32000, -19.61, -18.04),
325 std::tr1::make_tuple(192000, 32000, -21.02, -10.94)));
327 } // namespace webrtc