sinusoidal_linear_chirp_source.h (1969B)
1 /* 2 * Copyright (c) 2013 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 // Modified from the Chromium original here: 12 // src/media/base/sinc_resampler_unittest.cc 13 14 #ifndef COMMON_AUDIO_RESAMPLER_SINUSOIDAL_LINEAR_CHIRP_SOURCE_H_ 15 #define COMMON_AUDIO_RESAMPLER_SINUSOIDAL_LINEAR_CHIRP_SOURCE_H_ 16 17 #include <cstddef> 18 19 #include "common_audio/resampler/sinc_resampler.h" 20 21 namespace webrtc { 22 23 // Fake audio source for testing the resampler. Generates a sinusoidal linear 24 // chirp (http://en.wikipedia.org/wiki/Chirp) which can be tuned to stress the 25 // resampler for the specific sample rate conversion being used. 26 class SinusoidalLinearChirpSource : public SincResamplerCallback { 27 public: 28 // `delay_samples` can be used to insert a fractional sample delay into the 29 // source. It will produce zeros until non-negative time is reached. 30 SinusoidalLinearChirpSource(int sample_rate, 31 size_t samples, 32 double max_frequency, 33 double delay_samples); 34 35 ~SinusoidalLinearChirpSource() override {} 36 37 SinusoidalLinearChirpSource(const SinusoidalLinearChirpSource&) = delete; 38 SinusoidalLinearChirpSource& operator=(const SinusoidalLinearChirpSource&) = 39 delete; 40 41 void Run(size_t frames, float* destination) override; 42 43 double Frequency(size_t position); 44 45 private: 46 static constexpr int kMinFrequency = 5; 47 48 int sample_rate_; 49 size_t total_samples_; 50 double max_frequency_; 51 double k_; 52 size_t current_index_; 53 double delay_samples_; 54 }; 55 56 } // namespace webrtc 57 58 #endif // COMMON_AUDIO_RESAMPLER_SINUSOIDAL_LINEAR_CHIRP_SOURCE_H_