mirror of
https://github.com/DSheirer/sdrtrunk.git
synced 2026-11-13 09:07:27 -05:00
[WIP] Updates the AM decoder module.
Removes a number of unused classes in an effort to remove RealBuffer usage across the codebase (has been replaced by ReusableBuffers).
This commit is contained in:
Denny
@@ -2,32 +2,32 @@ package io.github.dsheirer.dsp.gain;
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import io.github.dsheirer.buffer.DoubleCircularBuffer;
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import io.github.dsheirer.buffer.RealCircularBuffer;
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import java.util.concurrent.atomic.AtomicBoolean;
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import io.github.dsheirer.sample.buffer.ReusableBuffer;
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import io.github.dsheirer.sample.buffer.ReusableBufferQueue;
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/*******************************************************************************
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* SDR Trunk
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* Copyright (C) 2014 Dennis Sheirer
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* Copyright (C) 2014 - 2018 Dennis Sheirer
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* Copyright (C) 2011 Alex Csete
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* Copyright (C) 2010 Moe Wheatley
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*
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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*
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* This program 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
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* GNU General Public License for more details.
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*
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>
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*
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*
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* ---------------------------------------------------
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* Ported from Alex Csete's gqrx source code at:
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* https://github.com/csete/gqrx/blob/74ba2742c89b0dfb66854fc9f72d19e5c6e355b6/dsp/agc_impl.cpp
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*
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*
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* This Software is released under the "Simplified BSD License" + + +
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* Copyright 2010 Moe Wheatley. All rights reserved.
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*
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@@ -60,165 +60,189 @@ import java.util.concurrent.atomic.AtomicBoolean;
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******************************************************************************/
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public class AutomaticGainControl
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{
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private static final double SAMPLE_RATE = 48000;
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/* Signal delay line - time delay in seconds */
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private static final double SAMPLE_RATE = 48000;
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/* Signal delay line - time delay in seconds */
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// private static final double DELAY_TIME_CONSTANT = 0.015;
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private static final double DELAY_TIME_CONSTANT = 0.01;
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private static final double DELAY_TIME_CONSTANT = 0.01;
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/* Peak detector window - time delay in seconds */
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private static final double WINDOW_TIME_CONSTANT = 0.018;
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/* Peak detector window - time delay in seconds */
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private static final double WINDOW_TIME_CONSTANT = 0.018;
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/* Attack time constants in seconds */
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private static final double ATTACK_RISE_TIME_CONSTANT = 0.002;
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private static final double ATTACK_FALL_TIME_CONSTANT = 0.005;
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/* Attack time constants in seconds */
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private static final double ATTACK_RISE_TIME_CONSTANT = 0.002;
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private static final double ATTACK_FALL_TIME_CONSTANT = 0.005;
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private static final double ATTACK_RISE_ALPHA = 1.0 -
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Math.exp( -1.0 / SAMPLE_RATE * ATTACK_RISE_TIME_CONSTANT );
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private static final double ATTACK_RISE_ALPHA = 1.0 -
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Math.exp(-1.0 / SAMPLE_RATE * ATTACK_RISE_TIME_CONSTANT);
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private static final double ATTACK_FALL_ALPHA = 1.0 -
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Math.exp( -1.0 / SAMPLE_RATE * ATTACK_FALL_TIME_CONSTANT );
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private static final double ATTACK_FALL_ALPHA = 1.0 -
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Math.exp(-1.0 / SAMPLE_RATE * ATTACK_FALL_TIME_CONSTANT);
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/* AGC decay value in milliseconds (20 to 5000) */
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private static final double DECAY = 200;
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/* Ratio between rise and fall times of decay time constants - adjust for
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* best action with SSB */
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private static final double DECAY_RISEFALL_RATIO = 0.3;
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/* AGC decay value in milliseconds (20 to 5000) */
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private static final double DECAY = 200;
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private static final double DECAY_RISE_ALPHA = 1.0 -
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Math.exp( -1.0 / ( SAMPLE_RATE * DECAY * .001 * DECAY_RISEFALL_RATIO ) );
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/* Ratio between rise and fall times of decay time constants - adjust for
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* best action with SSB */
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private static final double DECAY_RISEFALL_RATIO = 0.3;
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private static final double DECAY_FALL_ALPHA = 1.0 -
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Math.exp( -1.0 / ( SAMPLE_RATE * DECAY * .001 ) );
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private static final double DECAY_RISE_ALPHA = 1.0 -
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Math.exp(-1.0 / (SAMPLE_RATE * DECAY * .001 * DECAY_RISEFALL_RATIO));
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/* Hang timer release decay time constant in seconds */
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@SuppressWarnings( "unused" )
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private static final double RELEASE_TIME_CONSTANT = 0.05;
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private static final double DECAY_FALL_ALPHA = 1.0 -
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Math.exp(-1.0 / (SAMPLE_RATE * DECAY * .001));
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/* Specifies the AGC Knee in dB if AGC is active (nominal range -160 to 0 dB) */
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private static final double THRESHOLD = -100;
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/* Hang timer release decay time constant in seconds */
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@SuppressWarnings("unused")
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private static final double RELEASE_TIME_CONSTANT = 0.05;
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/* Limit output to about 3db of maximum */
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private static final double AGC_OUT_SCALE = 0.7;
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/* Specifies the AGC Knee in dB if AGC is active (nominal range -160 to 0 dB) */
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private static final double THRESHOLD = -100;
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/* Keep max input and output the same */
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private static final double MAX_AMPLITUDE = 32767.0; //1.0;
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private static final double MAX_MANUAL_AMPLITUDE = 32767.0; //1.0;
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/* Specifies AGC manual gain in dB if AGC is not active ( 0 to 100 dB) */
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private static final double MANUAL_GAIN = 0.0;
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/* Limit output to about 3db of maximum */
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private static final double AGC_OUT_SCALE = 0.7;
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private static final double MANUAL_AGC_GAIN = MAX_MANUAL_AMPLITUDE *
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Math.pow( 10.0, MANUAL_GAIN / 20.0 );
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/* Keep max input and output the same */
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private static final double MAX_AMPLITUDE = 32767.0; //1.0;
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private static final double MAX_MANUAL_AMPLITUDE = 32767.0; //1.0;
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/* Specifies dB reduction in output at knee from max output level (0 - 10dB) */
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private static final double SLOPE_FACTOR = 2.0;
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/* Specifies AGC manual gain in dB if AGC is not active ( 0 to 100 dB) */
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private static final double MANUAL_GAIN = 0.0;
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private static final double KNEE = THRESHOLD / 20.0;
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private static final double MANUAL_AGC_GAIN = MAX_MANUAL_AMPLITUDE *
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Math.pow(10.0, MANUAL_GAIN / 20.0);
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private static final double GAIN_SLOPE = SLOPE_FACTOR / 100.0;
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/* Specifies dB reduction in output at knee from max output level (0 - 10dB) */
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private static final double SLOPE_FACTOR = 2.0;
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private static final double FIXED_GAIN = AGC_OUT_SCALE *
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Math.pow( 10.0, KNEE * ( GAIN_SLOPE - 1.0 ) );
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/* Constant for calc log() so that a value of 0 magnitude = -8 */
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private static final double MIN_CONSTANT = 3.2767E-4;
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private AtomicBoolean mAGCEnabled = new AtomicBoolean( true );
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private double mPeakMagnitude = 0.0;
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private double mAttackAverage = 0.0;
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private double mDecayAverage = 0.0;
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private RealCircularBuffer mDelayBuffer =
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new RealCircularBuffer( (int)( SAMPLE_RATE * DELAY_TIME_CONSTANT ) );
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private DoubleCircularBuffer mMagnitudeBuffer =
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new DoubleCircularBuffer( (int)( SAMPLE_RATE * WINDOW_TIME_CONSTANT ) );
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public AutomaticGainControl()
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{
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}
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private static final double KNEE = THRESHOLD / 20.0;
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public float process( float currentSample )
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private static final double GAIN_SLOPE = SLOPE_FACTOR / 100.0;
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private static final double FIXED_GAIN = AGC_OUT_SCALE *
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Math.pow(10.0, KNEE * (GAIN_SLOPE - 1.0));
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/* Constant for calc log() so that a value of 0 magnitude = -8 */
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private static final double MIN_CONSTANT = 3.2767E-4;
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private boolean mAGCEnabled = true;
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private double mPeakMagnitude = 0.0;
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private double mAttackAverage = 0.0;
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private double mDecayAverage = 0.0;
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private RealCircularBuffer mDelayBuffer = new RealCircularBuffer((int)(SAMPLE_RATE * DELAY_TIME_CONSTANT));
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private DoubleCircularBuffer mMagnitudeBuffer = new DoubleCircularBuffer((int)(SAMPLE_RATE * WINDOW_TIME_CONSTANT));
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private ReusableBufferQueue mReusableBufferQueue = new ReusableBufferQueue("AutomaticGainControl");
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public AutomaticGainControl()
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{
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float delayedSample = mDelayBuffer.putAndGet( currentSample );
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double gain = MANUAL_AGC_GAIN;
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if( mAGCEnabled.get() )
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{
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double currentMagnitude = Math.log10( Math.abs( currentSample ) +
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MIN_CONSTANT ) - Math.log10( MAX_AMPLITUDE );
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double delayedMagnitude = mMagnitudeBuffer.get( currentMagnitude );
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if( currentMagnitude > mPeakMagnitude )
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{
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/* Use current magnitude as peak if it's larger */
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mPeakMagnitude = currentMagnitude;
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}
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else if( delayedMagnitude == mPeakMagnitude )
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{
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/* If delayed magnitude is the current peak, then find a new peak */
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mPeakMagnitude = mMagnitudeBuffer.max();
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}
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/* Exponential decay mode */
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if( mPeakMagnitude > mAttackAverage )
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{
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mAttackAverage = ( ( 1.0 - ATTACK_RISE_ALPHA ) * mAttackAverage ) +
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( ATTACK_RISE_ALPHA * mPeakMagnitude );
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}
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else
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{
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mAttackAverage = ( ( 1.0 - ATTACK_FALL_ALPHA ) * mAttackAverage ) +
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( ATTACK_FALL_ALPHA * mPeakMagnitude );
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}
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if( mPeakMagnitude > mDecayAverage )
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{
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mDecayAverage = ( ( 1.0 - DECAY_RISE_ALPHA ) * mDecayAverage ) +
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( DECAY_RISE_ALPHA * mPeakMagnitude );
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}
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else
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{
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mDecayAverage = ( ( 1.0 - DECAY_FALL_ALPHA ) * mDecayAverage ) +
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( DECAY_RISE_ALPHA * mPeakMagnitude );
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}
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double magnitude = ( mAttackAverage > mDecayAverage ) ?
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mAttackAverage : mDecayAverage;
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if( magnitude < KNEE )
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{
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gain = FIXED_GAIN;
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}
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else
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{
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gain = AGC_OUT_SCALE * Math.pow( 10.0,
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magnitude * ( GAIN_SLOPE - 1.0 ) );
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}
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}
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return (float)( delayedSample * gain );
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}
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/**
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* Enables or disables Automatic Gain Control (AGC).
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*/
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public void setAGCEnabled( boolean enabled )
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{
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mAGCEnabled.set( enabled );
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}
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/**
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* Indicates if AGC is enabled
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* @return true=AGC, false=MANUAL GAIN
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*/
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public boolean isAGCEnabled()
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{
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return mAGCEnabled.get();
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}
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/**
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* Applies gain to the samples contained in the input buffer and returns a new buffer containing the
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* processed samples.
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*
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* @param input samples to process
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* @return output samples with gain applied
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*/
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public ReusableBuffer process(ReusableBuffer input)
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{
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ReusableBuffer output = mReusableBufferQueue.getBuffer(input.getSampleCount());
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float[] inputSamples = input.getSamples();
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float[] outputSamples = output.getSamples();
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for(int x = 0; x < inputSamples.length; x++)
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{
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outputSamples[x] = process(inputSamples[x]);
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}
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input.decrementUserCount();
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output.incrementUserCount();
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return output;
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}
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/**
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* Processes the input sample and applies gain
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*
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* @param currentSample to process
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* @return gain applied sample
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*/
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public float process(float currentSample)
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{
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float delayedSample = mDelayBuffer.putAndGet(currentSample);
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double gain = MANUAL_AGC_GAIN;
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if(mAGCEnabled)
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{
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double currentMagnitude = Math.log10(Math.abs(currentSample) + MIN_CONSTANT) - Math.log10(MAX_AMPLITUDE);
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double delayedMagnitude = mMagnitudeBuffer.get(currentMagnitude);
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if(currentMagnitude > mPeakMagnitude)
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{
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/* Use current magnitude as peak if it's larger */
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mPeakMagnitude = currentMagnitude;
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}
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else if(delayedMagnitude == mPeakMagnitude)
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{
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/* If delayed magnitude is the current peak, then find a new peak */
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mPeakMagnitude = mMagnitudeBuffer.max();
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}
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/* Exponential decay mode */
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if(mPeakMagnitude > mAttackAverage)
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{
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mAttackAverage = ((1.0 - ATTACK_RISE_ALPHA) * mAttackAverage) + (ATTACK_RISE_ALPHA * mPeakMagnitude);
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}
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else
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{
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mAttackAverage = ((1.0 - ATTACK_FALL_ALPHA) * mAttackAverage) + (ATTACK_FALL_ALPHA * mPeakMagnitude);
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}
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if(mPeakMagnitude > mDecayAverage)
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{
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mDecayAverage = ((1.0 - DECAY_RISE_ALPHA) * mDecayAverage) + (DECAY_RISE_ALPHA * mPeakMagnitude);
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}
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else
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{
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mDecayAverage = ((1.0 - DECAY_FALL_ALPHA) * mDecayAverage) + (DECAY_RISE_ALPHA * mPeakMagnitude);
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}
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double magnitude = (mAttackAverage > mDecayAverage) ? mAttackAverage : mDecayAverage;
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if(magnitude < KNEE)
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{
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gain = FIXED_GAIN;
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}
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else
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{
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gain = AGC_OUT_SCALE * Math.pow(10.0, magnitude * (GAIN_SLOPE - 1.0));
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}
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}
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return (float)(delayedSample * gain);
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}
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/**
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* Enables or disables Automatic Gain Control (AGC).
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*/
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public void setAGCEnabled(boolean enabled)
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{
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mAGCEnabled = enabled;
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}
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/**
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* Indicates if AGC is enabled
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*
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* @return true=AGC, false=MANUAL GAIN
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*/
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public boolean isAGCEnabled()
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{
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return mAGCEnabled;
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}
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}
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@@ -1,53 +0,0 @@
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package io.github.dsheirer.dsp.gain;
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import io.github.dsheirer.sample.Listener;
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import io.github.dsheirer.sample.real.RealBuffer;
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public class AutomaticGainControl_RB extends AutomaticGainControl
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implements Listener<RealBuffer>
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{
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private Listener<RealBuffer> mListener;
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public AutomaticGainControl_RB()
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{
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}
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public void dispose()
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{
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mListener = null;
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}
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/**
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* Applies AGC to a buffer of real (float) samples
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*/
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public RealBuffer process( RealBuffer buffer )
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{
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float[] samples = buffer.getSamples();
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for( int x = 0; x < samples.length; x++ )
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{
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samples[ x ] = process( samples[ x ] );
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}
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return buffer;
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}
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@Override
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public void receive( RealBuffer buffer )
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{
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if( mListener != null )
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{
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mListener.receive( process( buffer ) );
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}
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}
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public void setListener( Listener<RealBuffer> listener )
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{
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mListener = listener;
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}
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public void removeListener()
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{
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mListener = null;
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}
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}
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Reference in New Issue
Block a user