58 lines
1,015 B
C
58 lines
1,015 B
C
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#include "filter.h"
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#include <math.h>
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#include <string.h>
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void FilterFoldedBinsIIRTWOPASS( float * folded, int bins, float iir )
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{
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int i;
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float inv = 1.0 - iir;
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float v = 0.0;
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//Go through the data once, forward.
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for( i = 0; i < bins; i++ )
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{
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v = v * iir + folded[i] * inv;
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}
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//Start applying filter on second pass.
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for( i = 0; i < bins; i++ )
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{
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folded[i] = v * iir + folded[i] * inv;
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}
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//Go backwards.
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v = 0;
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for( i = bins-1; i >= 0; i-- )
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{
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v = v * iir + folded[i] * inv;
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}
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//Start applying filter on second pass.
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for( i = bins-1; i >= 0; i-- )
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{
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folded[i] = v * iir + folded[i] * inv;
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}
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}
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void FilterFoldedBinsBlob( float * folded, int bins, float strength, int iter )
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{
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float tmp[bins];
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int i;
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int j;
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for( j = 0; j < iter; j++ )
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{
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memcpy( tmp, folded, sizeof( tmp ) );
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for( i = 0; i < bins; i++ )
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{
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float left = tmp[(i-1+bins)%bins];
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float right = tmp[(i-1+bins)%bins];
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folded[i] = folded[i] * (1.-strength) + (left + right) * strength * 0.5;
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}
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}
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}
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