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Implemented dynamic low-pass filter for SB16/AWE32 DSP playback.

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This commit is contained in:
SarahW 2018-02-12 12:00:32 +00:00
commit 75ec50cfd7
3 changed files with 77 additions and 7 deletions
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30
src/filters.h
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@ -345,3 +345,33 @@ static inline float dac_iir(int i, float NewSample) {
return y[i][0];
}
#define SB16_NCoef 51
extern float low_fir_sb16_coef[SB16_NCoef];
static inline float low_fir_sb16(int i, float NewSample)
{
static float x[2][SB16_NCoef+1]; //input samples
static int pos = 0;
float out = 0.0;
int n;
//Calculate the new output
x[i][pos] = NewSample;
for (n = 0; n < ((SB16_NCoef+1)-pos); n++)
out += low_fir_sb16_coef[n] * x[i][n+pos];
for (; n < SB16_NCoef; n++)
out += low_fir_sb16_coef[n] * x[i][(n+pos) - (SB16_NCoef+1)];
if (i == 1)
{
pos++;
if (pos > SB16_NCoef)
pos = 0;
}
return out;
}