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92ea95e34a
In https://webrtc-review.googlesource.com/c/src/+/1560 we moved WebRTC from src/webrtc to src/ (in order to preserve an healthy git history). This CL takes care of fixing header guards, #include paths, etc... NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true TBR=tommi@webrtc.org Bug: chromium:611808 Change-Id: Iea91618212bee0af16aa3f05071eab8f93706578 Reviewed-on: https://webrtc-review.googlesource.com/1561 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Henrik Kjellander <kjellander@webrtc.org> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#19846}
58 lines
2 KiB
C++
58 lines
2 KiB
C++
/*
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* Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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// MSVC++ requires this to be set before any other includes to get M_PI.
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#define _USE_MATH_DEFINES
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#include "common_audio/resampler/sinusoidal_linear_chirp_source.h"
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#include <math.h>
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namespace webrtc {
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SinusoidalLinearChirpSource::SinusoidalLinearChirpSource(int sample_rate,
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size_t samples,
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double max_frequency,
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double delay_samples)
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: sample_rate_(sample_rate),
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total_samples_(samples),
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max_frequency_(max_frequency),
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current_index_(0),
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delay_samples_(delay_samples) {
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// Chirp rate.
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double duration = static_cast<double>(total_samples_) / sample_rate_;
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k_ = (max_frequency_ - kMinFrequency) / duration;
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}
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void SinusoidalLinearChirpSource::Run(size_t frames, float* destination) {
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for (size_t i = 0; i < frames; ++i, ++current_index_) {
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// Filter out frequencies higher than Nyquist.
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if (Frequency(current_index_) > 0.5 * sample_rate_) {
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destination[i] = 0;
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} else {
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// Calculate time in seconds.
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if (current_index_ < delay_samples_) {
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destination[i] = 0;
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} else {
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// Sinusoidal linear chirp.
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double t = (current_index_ - delay_samples_) / sample_rate_;
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destination[i] =
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sin(2 * M_PI * (kMinFrequency * t + (k_ / 2) * t * t));
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}
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}
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}
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}
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double SinusoidalLinearChirpSource::Frequency(size_t position) {
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return kMinFrequency + (position - delay_samples_) *
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(max_frequency_ - kMinFrequency) / total_samples_;
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}
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} // namespace webrtc
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