mirror of
https://github.com/DSheirer/sdrtrunk.git
synced 2026-11-13 00:57:31 -05:00
e61c3a891c
Converted to use float primitives and to keep samples in buffer format until the sample rate is decimated to 48kHz. Added new non-recursive, CIC decimation filter -- untested Updated sound card/mixer input source management. Now testing for mono/stereo support for each card and limiting channel choices accordingly. Separated the mixersource into a ComplexMixer and and SimplexMixerSource. The ComplexMixer is used for sound card based tuners like the funcube. The SimplexMixerSource is used for demodulated sound card inputs. Interfaces for sample handling - standardized on using 'Complex' to indicate I/Q samples and 'Simplex' to indicate demodulated float samples. The processing chain now accepts either a decimated (48k) list of complex samples from a tuner channel source, or a 48k simplex buffer (array of demodulated float samples). Resolved issue with HackRF tuner not applying tuner configuration information.
94 lines
2.7 KiB
Java
94 lines
2.7 KiB
Java
/*******************************************************************************
|
|
* SDR Trunk
|
|
* Copyright (C) 2014 Dennis Sheirer
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>
|
|
******************************************************************************/
|
|
package dsp.nbfm;
|
|
|
|
import sample.Listener;
|
|
import sample.complex.ComplexSample;
|
|
import sample.simplex.SimplexSampleBroadcaster;
|
|
import sample.simplex.SimplexSampleListener;
|
|
import dsp.filter.ComplexFIRFilter;
|
|
import dsp.filter.FilterFactory;
|
|
import dsp.filter.Window.WindowType;
|
|
|
|
public class NBFMDemodulator implements Listener<ComplexSample>
|
|
{
|
|
private SimplexSampleBroadcaster mBroadcaster = new SimplexSampleBroadcaster();
|
|
private ComplexFIRFilter mIQFilter;
|
|
private FMDiscriminator mDiscriminator;
|
|
|
|
/**
|
|
* Implements a quadrature narrow-band demodulator that produces float
|
|
* valued demodulated, audio filtered output samples.
|
|
*/
|
|
public NBFMDemodulator()
|
|
{
|
|
this( FilterFactory.getLowPass( 48000, 4000, 73, WindowType.HAMMING ),
|
|
1.0002, true );
|
|
}
|
|
|
|
public NBFMDemodulator( double[] iqFilter, double iqGain, boolean afc )
|
|
{
|
|
mIQFilter = new ComplexFIRFilter( iqFilter, iqGain );
|
|
|
|
/**
|
|
* Add the FM polar discriminator with a gain of 32768, to match
|
|
* the fact that we're producing demodulated float values
|
|
*/
|
|
mDiscriminator = new FMDiscriminator( 32768 );
|
|
|
|
mIQFilter.setListener( mDiscriminator );
|
|
|
|
mDiscriminator.setListener( mBroadcaster );
|
|
}
|
|
|
|
public void dispose()
|
|
{
|
|
mDiscriminator.dispose();
|
|
|
|
mBroadcaster.dispose();
|
|
|
|
mIQFilter.dispose();
|
|
}
|
|
|
|
/**
|
|
* Receive method for complex samples that are fed into this class to be
|
|
* processed
|
|
*/
|
|
@Override
|
|
public void receive( ComplexSample sample )
|
|
{
|
|
mIQFilter.receive( sample );
|
|
}
|
|
|
|
/**
|
|
* Adds a listener to receive demodulated samples
|
|
*/
|
|
public void addListener( SimplexSampleListener listener )
|
|
{
|
|
mBroadcaster.addListener( listener );
|
|
}
|
|
|
|
/**
|
|
* Removes a listener from receiving demodulated samples
|
|
*/
|
|
public void removeListener( SimplexSampleListener listener )
|
|
{
|
|
mBroadcaster.removeListener( listener );
|
|
}
|
|
}
|