44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
#pragma once
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#include <math.h>
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namespace trnr {
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struct demo_noise {
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double samplerate;
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int counter = 0;
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// initialize with sane defaults
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int noise_len_sec = 3;
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int pause_len_sec = 17;
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float noise_gain = 0.1f;
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};
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inline void demo_nose_init(demo_noise& d, double samplerate)
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{
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d.samplerate = samplerate;
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d.counter = 0;
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}
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// overwrites the input buffer with noise in the specified time frame
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inline void process_block(demo_noise& d, float** samples, int blocksize)
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{
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int noise_len_samples = d.noise_len_sec * d.samplerate;
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int pause_len_samples = d.pause_len_sec * d.samplerate;
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int total_len_samples = noise_len_samples + pause_len_samples;
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for (int s = 0; s < blocksize; s++) {
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d.counter++;
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if (d.counter > total_len_samples) { d.counter = 0; }
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if (d.counter > pause_len_samples) {
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float r1 = static_cast<float>(rand()) / static_cast<float>(RAND_MAX);
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float r2 = static_cast<float>(rand()) / static_cast<float>(RAND_MAX);
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float noise = static_cast<float>(sqrt(-2.0 * log(r1)) * cos(2.0 * M_PI * r2));
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samples[0][s] = samples[1][s] = noise * d.noise_gain;
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}
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}
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}
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} // namespace trnr
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