Reputation: 3
I'm creating a guitar tuner in Java on the netbeans IDE and I want my program to stop capturing live audio as soon as a certain frequency has been read. This code below starts the audio capture but stops instantly. I want it to stop as soon as it reaches the frequency of the Low E string for example. I've used this website for help so far: https://docs.oracle.com/javase/tutorial/sound/capturing.html
//libraries
import static java.awt.SystemColor.info;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import static java.lang.System.in;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine.Info;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.TargetDataLine;
public class AudioInputPractice {
/**
* @param args the command line arguments
* @throws javax.sound.sampled.LineUnavailableException
*/
public int read(byte[] b, int off, int len) throws IOException{
return in.read(b, off, len);
}
public static void main(String[] args){
System.out.println("Starting sound test...");
//audio
try
{
TargetDataLine line;
AudioFormat format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, 44100, 16, 2, 4, 4100, false);
DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);
if (!AudioSystem.isLineSupported(info)) {System.err.println("Line not Supported");}
line = (TargetDataLine)AudioSystem.getLine(info);
line.open();
ByteArrayOutputStream out= new ByteArrayOutputStream();
int numBytesRead;
byte[] data = new byte[line.getBufferSize() / 5];
System.out.println("Starting recording...");
line.start();
numBytesRead = line.read(data, 0 , data.length);
out.write(data, 0, numBytesRead);
}
catch (LineUnavailableException ex)
{
System.out.println("Error");
}
}
}
Upvotes: 0
Views: 73
Reputation: 7910
The code you have only reads one buffer's worth of data!
The usual thing is to put the read
command into a conditional while
loop. For your condition, it can be something as simple as a boolean called isRunning
. As you read the data, you will presumably be shipping it on to your pitch analyzer.
The Java Tutorials has an example of such a while
loop in Using Files and Format Converters. It's the first major code quote in this article. A snippet is shown below. Reading from a TargetDataLine is similar to reading from an AudioInputStream as is done in the example.
// Set an arbitrary buffer size of 1024 frames.
int numBytes = 1024 * bytesPerFrame;
byte[] audioBytes = new byte[numBytes];
try {
int numBytesRead = 0;
int numFramesRead = 0;
// Try to read numBytes bytes from the file.
while ((numBytesRead =
audioInputStream.read(audioBytes)) != -1) {
// Calculate the number of frames actually read.
numFramesRead = numBytesRead / bytesPerFrame;
totalFramesRead += numFramesRead;
// Here, do something useful with the audio data that's
// now in the audioBytes array...
}
} catch (Exception ex) {
// Handle the error...
}
The condition in the while
is handled differently here. Often a boolean
is used instead, as I first suggested, especially in cases where one wishes to use loose coupling as the mechanism to open or close the spigot, so to speak.
Upvotes: 0