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#35 Updates AM & NBFM decoders to use Adaptive Squelch, a power squelch that includes an adaptive noise floor monitor. Implements vectorized magnitude operations for AM & FM decoders. Adds talkgroup assignment and squelch controls to AM channel configuration editor. Implements new AM gain control that attempts to normalize audio gain quickly at beginning of call/transmission and maintains that gain across lifecycle of the call and resets the gain for the next call. (#1540)

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Notes on usage:
- When using either AM or FM squelch control use either the Heterodyne channelizer or if using the Polyphase channelizer, avoid using trunk tracking decoders like DMR or P25 or set the squelch threshold high enough to avoid changes in noise floor from polyphase channelizer where it can vary between using the one channel or the two-channel combined channel sources.

Co-authored-by: Dennis Sheirer <dsheirer@github.com>
This commit is contained in:
Denny Sheirer
2023-05-07 07:27:44 -04:00
committed by GitHub
parent 5654254cbb
commit 4f8b8e978b
74 changed files with 4630 additions and 2012 deletions
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34
src/main/java/io/github/dsheirer/dsp/squelch/PowerSquelch.java
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@@ -1,8 +1,28 @@
/*
* *****************************************************************************
* Copyright (C) 2014-2023 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 io.github.dsheirer.dsp.squelch;
import io.github.dsheirer.dsp.filter.iir.SinglePoleIirFilter;
import io.github.dsheirer.sample.Listener;
import io.github.dsheirer.source.SourceEvent;
import org.apache.commons.math3.util.FastMath;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@@ -17,8 +37,8 @@ public class PowerSquelch implements Listener<SourceEvent>
private static final Logger mLog = LoggerFactory.getLogger(PowerSquelch.class);
private State mState = State.MUTE;
private SinglePoleIirFilter mFilter;
private double mPower = 0.0f;
private double mSquelchThreshold;
private float mPower = 0.0f;
private float mSquelchThreshold;
private int mRampThreshold;
private int mRampCount;
private boolean mSquelchChanged = false;
@@ -42,7 +62,7 @@ public class PowerSquelch implements Listener<SourceEvent>
* @param ramp count of samples before transition between mute and unmute. Setting this value to zero
* causes immediate mute and unmute. Set to higher count to prevent mute/unmute flapping.
*/
public PowerSquelch(float alpha, double squelchThreshold, int ramp)
public PowerSquelch(float alpha, float squelchThreshold, int ramp)
{
mFilter = new SinglePoleIirFilter(alpha);
setSquelchThreshold(squelchThreshold);
@@ -64,9 +84,9 @@ public class PowerSquelch implements Listener<SourceEvent>
* Squelch threshold value
* @return value in decibels
*/
public double getSquelchThreshold()
public float getSquelchThreshold()
{
return 10.0 * Math.log10(mSquelchThreshold);
return 10.0f * (float)FastMath.log10(mSquelchThreshold);
}
/**
@@ -75,7 +95,7 @@ public class PowerSquelch implements Listener<SourceEvent>
*/
public void setSquelchThreshold(double squelchThreshold)
{
mSquelchThreshold = Math.pow(10.0, squelchThreshold / 10.0);
mSquelchThreshold = (float) FastMath.pow(10.0, squelchThreshold / 10.0);
broadcast(SourceEvent.squelchThreshold(null, squelchThreshold));
}
@@ -268,7 +288,7 @@ public class PowerSquelch implements Listener<SourceEvent>
{
if(sourceEvent.getEvent() == SourceEvent.Event.REQUEST_CHANGE_SQUELCH_THRESHOLD)
{
setSquelchThreshold(sourceEvent.getValue().doubleValue());
setSquelchThreshold(sourceEvent.getValue().floatValue());
}
else if(sourceEvent.getEvent() == SourceEvent.Event.REQUEST_CURRENT_SQUELCH_THRESHOLD)
{