42eefe90bf
This high-pass filter filters out DC and frequencies below 300 Hz. Now de-emphases will not cause low frequencies to saturate audio level range or cause too high levels on low frequencies.
20 lines
391 B
C
20 lines
391 B
C
typedef struct emphasis {
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struct {
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double x_last;
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double factor;
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double amp;
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} p;
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struct {
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double y_last;
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double z_last;
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double d_factor;
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double h_factor;
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double amp;
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} d;
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} emphasis_t;
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int init_emphasis(emphasis_t *state, int samplerate);
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void pre_emphasis(emphasis_t *state, int16_t *samples, int num);
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void de_emphasis(emphasis_t *state, int16_t *samples, int num);
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