/*
This file is part of Subsonic.
Subsonic 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.
Subsonic 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 Subsonic. If not, see .
Copyright 2009 (C) Sindre Mehus
*/
package net.sourceforge.subsonic.service.jukebox;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.util.concurrent.atomic.AtomicReference;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.FloatControl;
import javax.sound.sampled.SourceDataLine;
import org.apache.commons.io.IOUtils;
import net.sourceforge.subsonic.Logger;
import net.sourceforge.subsonic.service.JukeboxService;
import static net.sourceforge.subsonic.service.jukebox.AudioPlayer.State.*;
/**
* A simple wrapper for playing sound from an input stream.
*
* Supports pause and resume, but not restarting.
*
* @author Sindre Mehus
* @version $Id$
*/
public class AudioPlayer {
private static final Logger LOG = Logger.getLogger(JukeboxService.class);
private final InputStream in;
private final Listener listener;
private final SourceDataLine line;
private final AtomicReference state = new AtomicReference(PAUSED);
private FloatControl gainControl;
public AudioPlayer(InputStream in, Listener listener) throws Exception {
this.in = new BufferedInputStream(in);
this.listener = listener;
AudioFormat format = AudioSystem.getAudioFileFormat(this.in).getFormat();
line = AudioSystem.getSourceDataLine(format);
line.open(format);
LOG.debug("Opened line " + line);
if (line.isControlSupported(FloatControl.Type.MASTER_GAIN)) {
gainControl = (FloatControl) line.getControl(FloatControl.Type.MASTER_GAIN);
setGain(0.5f);
}
new AudioDataWriter();
}
/**
* Starts (or resumes) the player. This only has effect if the current state is
* {@link State#PAUSED}.
*/
public synchronized void play() {
if (state.get() == PAUSED) {
line.start();
setState(PLAYING);
}
}
/**
* Pauses the player. This only has effect if the current state is
* {@link State#PLAYING}.
*/
public synchronized void pause() {
if (state.get() == PLAYING) {
setState(PAUSED);
line.stop();
line.flush();
}
}
/**
* Closes the player, releasing all resources. After this the player state is
* {@link State#CLOSED} (unless the current state is {@link State#EOM}).
*/
public synchronized void close() {
if (state.get() != CLOSED && state.get() != EOM) {
setState(CLOSED);
}
try {
line.stop();
} catch (Throwable x) {
LOG.warn("Failed to stop player: " + x, x);
}
try {
if (line.isOpen()) {
line.close();
LOG.debug("Closed line " + line);
}
} catch (Throwable x) {
LOG.warn("Failed to close player: " + x, x);
}
IOUtils.closeQuietly(in);
}
/**
* Returns the player state.
*/
public State getState() {
return state.get();
}
/**
* Sets the gain.
*
* @param gain The gain between 0.0 and 1.0.
*/
public void setGain(float gain) {
if (gainControl != null) {
double minGainDB = gainControl.getMinimum();
double maxGainDB = gainControl.getMaximum();
double ampGainDB = 0.5f * maxGainDB - minGainDB;
double cste = Math.log(10.0) / 20;
double valueDB = minGainDB + (1 / cste) * Math.log(1 + (Math.exp(cste * ampGainDB) - 1) * gain);
valueDB = Math.min(valueDB, maxGainDB);
valueDB = Math.max(valueDB, minGainDB);
gainControl.setValue((float) valueDB);
}
}
/**
* Returns the position in seconds.
*/
public int getPosition() {
return (int) (line.getMicrosecondPosition() / 1000000L);
}
private void setState(State state) {
if (this.state.getAndSet(state) != state && listener != null) {
listener.stateChanged(this, state);
}
}
private class AudioDataWriter implements Runnable {
public AudioDataWriter() {
new Thread(this).start();
}
public void run() {
try {
byte[] buffer = new byte[8192];
while (true) {
switch (state.get()) {
case CLOSED:
case EOM:
return;
case PAUSED:
Thread.sleep(250);
break;
case PLAYING:
int n = in.read(buffer);
if (n == -1) {
setState(EOM);
return;
}
line.write(buffer, 0, n);
break;
}
}
} catch (Throwable x) {
LOG.warn("Error when copying audio data: " + x, x);
} finally {
close();
}
}
}
public interface Listener {
void stateChanged(AudioPlayer player, State state);
}
public static enum State {
PAUSED,
PLAYING,
CLOSED,
EOM
}
}