kopia lustrzana https://github.com/f4exb/sdrangel
116 wiersze
4.0 KiB
C
116 wiersze
4.0 KiB
C
// DMR filter
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#define NZEROS 60
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float ngain = 7.423339364f;
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static float xv[NZEROS+1];
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float xcoeffs[] =
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{ -0.0083649323f, -0.0265444850f, -0.0428141462f, -0.0537571943f,
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-0.0564141052f, -0.0489161045f, -0.0310068662f, -0.0043393881f,
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+0.0275375106f, +0.0595423283f, +0.0857543325f, +0.1003565948f,
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+0.0986944931f, +0.0782804830f, +0.0395670487f, -0.0136691535f,
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-0.0744390415f, -0.1331834575f, -0.1788967208f, -0.2005995448f,
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-0.1889627181f, -0.1378439993f, -0.0454976231f, +0.0847488694f,
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+0.2444859269f, +0.4209222342f, +0.5982295474f, +0.7593684540f,
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+0.8881539892f, +0.9712773915f, +0.9999999166f, +0.9712773915f,
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+0.8881539892f, +0.7593684540f, +0.5982295474f, +0.4209222342f,
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+0.2444859269f, +0.0847488694f, -0.0454976231f, -0.1378439993f,
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-0.1889627181f, -0.2005995448f, -0.1788967208f, -0.1331834575f,
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-0.0744390415f, -0.0136691535f, +0.0395670487f, +0.0782804830f,
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+0.0986944931f, +0.1003565948f, +0.0857543325f, +0.0595423283f,
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+0.0275375106f, -0.0043393881f, -0.0310068662f, -0.0489161045f,
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-0.0564141052f, -0.0537571943f, -0.0428141462f, -0.0265444850f,
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-0.0083649323f,
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};
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// NXDN filter
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#define NXZEROS 134
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float nxgain = 15.95930463f;
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static float nxv[NXZEROS+1];
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float nxcoeffs[] =
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{ +0.031462429f, +0.031747267f, +0.030401148f, +0.027362877f,
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+0.022653298f, +0.016379869f, +0.008737200f, +0.000003302f,
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-0.009468531f, -0.019262057f, -0.028914291f, -0.037935027f,
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-0.045828927f, -0.052119261f, -0.056372283f, -0.058221106f,
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-0.057387924f, -0.053703443f, -0.047122444f, -0.037734535f,
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-0.025769308f, -0.011595336f, +0.004287292f, +0.021260954f,
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+0.038610717f, +0.055550276f, +0.071252765f, +0.084885375f,
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+0.095646450f, +0.102803611f, +0.105731303f, +0.103946126f,
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+0.097138329f, +0.085197939f, +0.068234131f, +0.046586711f,
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+0.020828821f, -0.008239664f, -0.039608255f, -0.072081234f,
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-0.104311776f, -0.134843790f, -0.162160200f, -0.184736015f,
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-0.201094346f, -0.209863285f, -0.209831516f, -0.200000470f,
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-0.179630919f, -0.148282051f, -0.105841323f, -0.052543664f,
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+0.011020985f, +0.083912428f, +0.164857408f, +0.252278939f,
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+0.344336996f, +0.438979335f, +0.534000832f, +0.627109358f,
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+0.715995947f, +0.798406824f, +0.872214756f, +0.935487176f,
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+0.986548646f, +1.024035395f, +1.046939951f, +1.054644241f,
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+1.046939951f, +1.024035395f, +0.986548646f, +0.935487176f,
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+0.872214756f, +0.798406824f, +0.715995947f, +0.627109358f,
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+0.534000832f, +0.438979335f, +0.344336996f, +0.252278939f,
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+0.164857408f, +0.083912428f, +0.011020985f, -0.052543664f,
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-0.105841323f, -0.148282051f, -0.179630919f, -0.200000470f,
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-0.209831516f, -0.209863285f, -0.201094346f, -0.184736015f,
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-0.162160200f, -0.134843790f, -0.104311776f, -0.072081234f,
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-0.039608255f, -0.008239664f, +0.020828821f, +0.046586711f,
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+0.068234131f, +0.085197939f, +0.097138329f, +0.103946126f,
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+0.105731303f, +0.102803611f, +0.095646450f, +0.084885375f,
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+0.071252765f, +0.055550276f, +0.038610717f, +0.021260954f,
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+0.004287292f, -0.011595336f, -0.025769308f, -0.037734535f,
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-0.047122444f, -0.053703443f, -0.057387924f, -0.058221106f,
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-0.056372283f, -0.052119261f, -0.045828927f, -0.037935027f,
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-0.028914291f, -0.019262057f, -0.009468531f, +0.000003302f,
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+0.008737200f, +0.016379869f, +0.022653298f, +0.027362877f,
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+0.030401148f, +0.031747267f, +0.031462429f,
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};
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short dsd_input_filter(short sample, int mode);
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short
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dmr_filter(short sample)
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{
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return dsd_input_filter(sample, 1);
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}
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short
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nxdn_filter(short sample)
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{
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return dsd_input_filter(sample, 2);
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}
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short
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dsd_input_filter(short sample, int mode)
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{
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float sum; int i;
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float gain;
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int zeros;
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float *v, *coeffs;
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switch(mode) {
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case 1:
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gain = ngain;
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v = xv;
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coeffs = xcoeffs;
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zeros = NZEROS;
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break;
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case 2:
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gain = nxgain;
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v = nxv;
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coeffs = nxcoeffs;
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zeros = NXZEROS;
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break;
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default:
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return sample;
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}
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for (i = 0; i < zeros; i++)
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v[i] = v[i+1];
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v[zeros] = sample; // unfiltered sample in
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sum = 0.0f;
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for (i = 0; i <= zeros; i++)
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sum += (coeffs[i] * v[i]);
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return sum / ngain; // filtered sample out
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} |