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Use GNU Radio emphasis filters, add filters generation scripts

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This commit is contained in:
Geoffrey Merck
2020-05-31 09:17:45 +02:00
parent eef364b1a9
commit 98cd2404f5
3 changed files with 97 additions and 3 deletions
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6
FMControl.cpp
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@@ -25,7 +25,7 @@
#endif
const float DEEMPHASIS_GAIN_DB = 0.0F;
const float PREEMPHASIS_GAIN_DB = 30.0F;
const float PREEMPHASIS_GAIN_DB = 0.0F;
const float FILTER_GAIN_DB = 0.0F;
const unsigned int FM_MASK = 0x00000FFFU;
@@ -39,8 +39,8 @@ m_filterStage1(NULL),
m_filterStage2(NULL),
m_filterStage3(NULL)
{
m_preemphasis = new CIIRDirectForm1Filter(0.38897032f, -0.32900053f, 0.0f, 1.0f, 0.28202918f, 0.0f, PREEMPHASIS_GAIN_DB);
m_deemphasis = new CIIRDirectForm1Filter(1.0f,0.28202918f, 0.0f, 0.38897032f, -0.32900053f, 0.0f, DEEMPHASIS_GAIN_DB);
m_preemphasis = new CIIRDirectForm1Filter(8.315375384336983F,-7.03334621603483F,0.0F,1.0F,0.282029168302153F,0.0F, PREEMPHASIS_GAIN_DB);
m_deemphasis = new CIIRDirectForm1Filter(0.07708787090460224F,0.07708787090460224F,0.0F,1.0F,-0.8458242581907955F,0.0F, DEEMPHASIS_GAIN_DB);
//cheby type 1 0.2dB cheby type 1 3rd order 300-2700Hz fs=8000
m_filterStage1 = new CIIRDirectForm1Filter(0.29495028f, 0.0f, -0.29495028f, 1.0f, -0.61384624f, -0.057158668f, FILTER_GAIN_DB);