jm.audio.RTMixer Maven / Gradle / Ivy
/*
Copyright (C) 2000 Andrew Sorensen & Andrew Brown
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 2 of the License, or 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package jm.audio;
import jm.audio.AudioChainListener;
import jm.audio.Instrument;
import jm.audio.AOException;
import jm.music.rt.RTLine;
import java.util.*;
import java.io.DataOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import javax.sound.sampled.*;
/**
* RTMixer is responsible for convolving the audio signals being pulled from
* n number of RTLines. RTMixer uses a single JMF Java Sound SourceDataLine
* object for writing the newly convolved signal to the audio device.
* Buffers of audio sample data are passed to the SourceDataLine at a rate
* set by the Control Rate value. The contol rate sets the size of the audio
* buffers used by RTMixer, SourceDataLine and Instrument.
* Information about sample rate and channels is retrieved from the first
* audio object of the first instrument of the first RTLine. Therefore,
* there is an assumption that all instruments have the same sample rate and
* number of channels.
*
* @author Andrew Sorensen
* @version 1.0,Sun Feb 25 18:42:43 2001
*/
public class RTMixer implements AudioChainListener{
//------------------------------------------
//Attributes
//------------------------------------------
/** The number of lines in the RTLine array */
private int totLines = 0;
/** count shows how many RTLines have passed RTMixer their full buffers */
private int count = 0;
/** sampleArray contains the convolution of all RTLines buffers */
private float[] sampleArray;
/** bos is used to convert sampleArray into a byte stream */
private ByteArrayOutputStream bos;
/** dos is used to help convert sampleArray into bos */
private DataOutputStream dos;
/** dline is the JFM java sound object which we write sampleArray to */
private SourceDataLine dline;
/** The sampleRate to be used when establishing the JMF SourceDataLine */
protected int sampleRate;
/** The number of channels to be used when setting up SourceDataLine */
protected int channels;
/** A Timer which keeps track of how many samples have been written since
* this object started */
public long currentTime = 0;
/** The control rate is used to set how often in instrument returns a full
* buffer of audio samples. This is acheived by changing the size of the
* instrument buffers.
* It is critical to the audio performance and can be tuned to the suit
* the different computers. Smaller values are prefereable because they give
* jMusic audio less latency, but values that are too small will cause
* the audio system to choke and splutter.
*/
protected double controlRate;//0.1 - 0.005
/** How far into the score we are in terms of beats */
private double scorePosition = 0.0;
/** RTLines associated with this RTMixer object */
private RTLine[] rtlines;
/** buffer size */
private int bufferSize;
//-------------------------------------
//Constructors
//-------------------------------------
/**
* The RTMixer constructor sets a number of attributes and opens a JMF java
* sound sourceDataLine.
* @param inst the Instruments to be processed by this object.
*/
public RTMixer(RTLine[] rtlines){
this(rtlines, 0.1); // value is the default control rate
}
/**
* The RTMixer constructor sets a number of attributes and opens a JMF java
* sound sourceDataLine.
* @param inst - The Instruments to be processed by this object.
* @param controlRate - Sets the regularity of audio parameter change.
* The control rate is used to set how often in instrument returns a full
* buffer of audio samples. This is acheived by changing the size of the
* instrument buffers.
* Control rate is critical to the audio performance and can be tuned to the suit
* different computers. Smaller values are prefereable because the resulting
* smaller buffer equates to a less latency, but values that are too small will cause
* the audio system to choke and splutter. Values typically fall in the rage 0.01 - 0.005.
*/
public RTMixer(RTLine[] rtlines, double controlRate){
this.rtlines = rtlines;
this.sampleRate = rtlines[0].getSampleRate();
this.channels = rtlines[0].getChannels();
this.controlRate = controlRate;
this.bufferSize = (int)(this.sampleRate * this.channels * this.controlRate);
while (this.bufferSize%4 != 0) {
this.controlRate += 0.001;
this.bufferSize = (int)(this.sampleRate * this.channels * this.controlRate);
}
// feed info down to lines and instruments
for(int i=0;i 1)
this.sampleArray[i] = this.sampleArray[i] / (this.totLines * 0.75f);
try{
dos.writeShort((short)(this.sampleArray[i]*32767));
}catch(IOException ioe){ioe.printStackTrace();}
this.sampleArray[i] = (float)0.0;
}
int returned = this.dline.write(bos.toByteArray(), 0, bos.size());
this.currentTime += (long)length;
}
/**
* This method creates an instance of the JMF SourceDataLine object. This
* becomes the sink for all sample data leaving jMusic.
* @param bufferSize the size to set the SourceDataLine's buffer size to.
*/
private void initJMFSound(int bufferSize){
//Set up jmf audio stuff
// AudioFormat af = new AudioFormat((float)this.sampleRate,16,
// this.channels,true,true);
AudioFormat af = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
(float)this.sampleRate, 16, this.channels, this.channels*2,
this.sampleRate,true);
DataLine.Info info = new DataLine.Info(SourceDataLine.class,af);
//System.out.println("Setting for audio line: "+info);
if(!AudioSystem.isLineSupported(info)){
System.out.println(info);
System.err.println("jMusic RTMixer error: JMF Line not supported. " +
"Real time audio must be 16 bit stereo ... exiting .. sorry :(");
System.exit(1);
}
try{
this.dline = (SourceDataLine)AudioSystem.getLine(info);
//multiply buffersize by 2 because this is bytes not shorts
this.dline.open(af, bufferSize*8); // 2 or 4?
this.dline.start();
}catch(Exception e){e.printStackTrace();}
}
public void finalize() {
System.out.println("RTMixer finalizing...");
try {
dos.close();
bos.close();
} catch(IOException e) {}
dline.stop();
dline.close();
}
}