-
Notifications
You must be signed in to change notification settings - Fork 240
/
AudioModule.java
168 lines (151 loc) · 5.31 KB
/
AudioModule.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/*
* *****************************************************************************
* 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.audio;
import io.github.dsheirer.alias.AliasList;
import io.github.dsheirer.audio.squelch.ISquelchStateListener;
import io.github.dsheirer.audio.squelch.SquelchState;
import io.github.dsheirer.audio.squelch.SquelchStateEvent;
import io.github.dsheirer.dsp.filter.FilterFactory;
import io.github.dsheirer.dsp.filter.design.FilterDesignException;
import io.github.dsheirer.dsp.filter.fir.FIRFilterSpecification;
import io.github.dsheirer.dsp.filter.fir.real.IRealFilter;
import io.github.dsheirer.dsp.filter.fir.remez.RemezFIRFilterDesigner;
import io.github.dsheirer.sample.Listener;
import io.github.dsheirer.sample.real.IRealBufferListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Provides packaging of demodulated audio sample buffers into audio segments for broadcast to registered listeners.
* Includes audio packet metadata in constructed audio segments.
*
* Incorporates audio squelch state listener to control if audio packets are broadcast or ignored.
*/
public class AudioModule extends AbstractAudioModule implements ISquelchStateListener, IRealBufferListener,
Listener<float[]>
{
private static final Logger mLog = LoggerFactory.getLogger(AudioModule.class);
private static float[] sHighPassFilterCoefficients;
private final boolean mAudioFilterEnable;
static
{
FIRFilterSpecification specification = FIRFilterSpecification.highPassBuilder()
.sampleRate(8000)
.stopBandCutoff(200)
.stopBandAmplitude(0.0)
.stopBandRipple(0.025)
.passBandStart(300)
.passBandAmplitude(1.0)
.passBandRipple(0.01)
.build();
try
{
RemezFIRFilterDesigner designer = new RemezFIRFilterDesigner(specification);
if(designer.isValid())
{
sHighPassFilterCoefficients = designer.getImpulseResponse();
}
}
catch(FilterDesignException fde)
{
mLog.error("Filter design error", fde);
}
}
private final IRealFilter mHighPassFilter = FilterFactory.getRealFilter(sHighPassFilterCoefficients);
private final SquelchStateListener mSquelchStateListener = new SquelchStateListener();
private SquelchState mSquelchState = SquelchState.SQUELCH;
/**
* Creates an Audio Module.
*
* @param aliasList for aliasing identifiers
* @param timeslot for this audio module
* @param maxAudioSegmentLength in milliseconds
* @param audioFilterEnable to enable or disable high-pass audio filter
*/
public AudioModule(AliasList aliasList, int timeslot, long maxAudioSegmentLength, boolean audioFilterEnable)
{
super(aliasList, timeslot, maxAudioSegmentLength);
mAudioFilterEnable = audioFilterEnable;
}
/**
* Creates an Audio Module.
* @param aliasList for aliasing identifiers
* @param audioFilterEnable to enable or disable high-pass audio filter
*/
public AudioModule(AliasList aliasList, boolean audioFilterEnable)
{
super(aliasList);
mAudioFilterEnable = audioFilterEnable;
}
@Override
protected int getTimeslot()
{
return 0;
}
@Override
public void reset()
{
getIdentifierCollection().clear();
}
@Override
public void start()
{
}
@Override
public Listener<SquelchStateEvent> getSquelchStateListener()
{
return mSquelchStateListener;
}
@Override
public void receive(float[] audioBuffer)
{
if(mSquelchState == SquelchState.UNSQUELCH)
{
if(mAudioFilterEnable)
{
audioBuffer = mHighPassFilter.filter(audioBuffer);
}
addAudio(audioBuffer);
}
}
@Override
public Listener<float[]> getBufferListener()
{
//Redirect received reusable buffers to the receive(buffer) method
return this;
}
/**
* Wrapper for squelch state listener
*/
public class SquelchStateListener implements Listener<SquelchStateEvent>
{
@Override
public void receive(SquelchStateEvent event)
{
SquelchState squelchState = event.getSquelchState();
if(mSquelchState != squelchState)
{
mSquelchState = squelchState;
if(mSquelchState == SquelchState.SQUELCH)
{
closeAudioSegment();
}
}
}
}
}