mirror of
https://github.com/alsa-project/alsa-utils
synced 2024-11-10 00:05:42 +01:00
42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
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#define ST2095_MAX_PEAK -9.5 // dB
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#define ST2095_HPFC 10.0 // Highpass filter cutoff in Hz
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#define ST2095_LPFC 22400.0 // Lowpass filter cutoff in Hz
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typedef struct
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{
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float maxAmp;
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int samplesPerPeriod;
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int randStep;
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int randMax;
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int seed;
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float scaleFactor;
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float w0t;
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float k;
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float k2;
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float LpFc;
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// biquad coefficients
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float hp1_a1, hp1_a2;
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float hp1_b0, hp1_b1, hp1_b2;
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float hp2_a1, hp2_a2;
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float hp2_b0, hp2_b1, hp2_b2;
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float lp1_a1, lp1_a2;
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float lp1_b0, lp1_b1, lp1_b2;
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float lp2_a1, lp2_a2;
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float lp2_b0, lp2_b1, lp2_b2;
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// delay-line variables for bandpass filter
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float hp1w1, hp1w2;
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float hp2w1, hp2w2;
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float lp1w1, lp1w2;
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float lp2w1, lp2w2;
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// delay-line variables for pink filter network
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float lp1, lp2, lp3, lp4, lp5, lp6;
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// statistics accumulator
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float accum;
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} st2095_noise_t;
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void initialize_st2095_noise( st2095_noise_t *st2095, int sample_rate );
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float generate_st2095_noise_sample( st2095_noise_t *st2095 );
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void reset_st2095_noise_measurement( st2095_noise_t *st2095 );
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float compute_st2095_noise_measurement( st2095_noise_t *st2095, int period );
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