kopia lustrzana https://github.com/Hamlib/Hamlib
93 wiersze
3.1 KiB
C++
93 wiersze
3.1 KiB
C++
/*
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* Hamlib GNUradio backend - Wide FM class
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* Copyright (c) 2003 by Stephane Fillod
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*
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*/
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#ifndef _WFM_H
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#define _WFM_H 1
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#include "demod.h"
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#include <VrQuadratureDemod.h> /* WFM */
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#include <GrFIRfilterFFF.h>
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class WFMDemodChainCF : public DemodChainCF {
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private:
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VrQuadratureDemod<d_oType> *q_demod;
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int RFIRdecimate;
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GrFIRfilterFFF *audio_filter;
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public:
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WFMDemodChainCF (VrSource<d_iType> *src, VrSink<d_oType> *snk, rmode_t mode, pbwidth_t width, int input_rate, freq_t centerfreq = 0) :
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DemodChainCF(src, snk, mode, width, input_rate, centerfreq) {
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CFIRdecimate = 125;
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RFIRdecimate = 5;
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const int quadRate = input_rate / CFIRdecimate;
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const int audioRate = quadRate / RFIRdecimate;
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rig_debug(RIG_DEBUG_VERBOSE, "Input Sampling Rate: %d\n", input_rate);
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rig_debug(RIG_DEBUG_VERBOSE, "Complex FIR decimation factor: %d\n", CFIRdecimate);
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rig_debug(RIG_DEBUG_VERBOSE, "QuadDemod Sampling Rate: %d\n", quadRate);
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rig_debug(RIG_DEBUG_VERBOSE, "Real FIR decimation factor: %d\n", RFIRdecimate);
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rig_debug(RIG_DEBUG_VERBOSE, "Audio Sampling Rate: %d\n", audioRate);
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// build channel filter
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//
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// note that the totally bogus transition width is because
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// we don't have enough mips right now to really do the right thing.
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// This results in a filter with 83 taps, which is just a few
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// more than the original 75 in microtune_fm_demo.
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if_width_of_transition_band = 8*100e3;
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// float --> float
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double width_of_transition_band = audioRate / 32;
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vector<float> audio_coeffs =
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gr_firdes::low_pass (1.0, // gain
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quadRate, // sampling rate
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audioRate/2 - width_of_transition_band, // low-pass cutoff freq
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width_of_transition_band,
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gr_firdes::WIN_HAMMING);
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rig_debug(RIG_DEBUG_VERBOSE, "Number of audio_coeffs: %d\n", audio_coeffs.size ());
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rig_debug(RIG_DEBUG_VERBOSE, "Low-pass cutoff freq: %d\n", audioRate/2 - (int)width_of_transition_band);
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audio_filter = new GrFIRfilterFFF(RFIRdecimate, audio_coeffs);
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q_demod = new VrQuadratureDemod<d_oType>(1.0);
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demod_in = q_demod;
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demod_out = audio_filter;
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NWO_CONNECT(demod_in, audio_filter);
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}
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~WFMDemodChainCF() { delete q_demod; delete audio_filter; }
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//void setWidth(pbwidth_t width) { }
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//void setFreq(freq_t centerfreq) { }
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void setRFgain(float gain) { q_demod->setGain(gain); }
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};
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#endif /* _WFM_H */
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