Multi tool use

Unwanted downsampling : Java Sound

I have been trying to manually read a wav file in Java and read an array of bytes then write to an audio buffer for playback. I am receiving playback but it is heavily distorted. Java sound supports 16 bit sample rates but not 24-bit.

I went in to Logic 9 and exported a 24-bit audio file in to 16-bit and then used with my program. Originally, the 24-bit samples would produces white noise. Now I can hear my sample but very distorted and sounds like it has been bit crushed.

Can anyone help me to get a clean signal?

I am very new to audio programming but I am currently working on a basic Digital Audio Workstation.

import javax.sound.sampled.*;
import javax.sound.sampled.DataLine.Info;
import javax.swing.filechooser.FileNameExtensionFilter;
import java.io.*;

public class AudioData {

private String filepath;
private String filepath1;
private File file;
private byte fileContent;
private Mixer mixer;
private Mixer.Info mixInfos;
private AudioInputStream input;
private ByteArrayOutputStream byteoutput;

public static void main (String args) {
AudioData audiodata = new AudioData();
}

public AudioData () {
filepath = "/Users/ivaannagen/Documents/Samples/Engineering Samples - Obscure Techno Vol 3 (WAV)/ES_OT3_Kit03_Gmin_130bpm/ES_OT3_Kit03_FX_Fast_Snare_Riser_Gmin_130bpm.wav";
filepath1 = "/Users/ivaannagen/Documents/Samples/dawsampletest.wav";
file = new File (filepath1);
readAudio();
}

public void readAudio () {
mixInfos = AudioSystem.getMixerInfo();

mixer = AudioSystem.getMixer(mixInfos[0]);

AudioFormat format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, 44100, 16, 2, 4, 44100, false);
// set up an audio format.

try {
DataLine.Info info = new DataLine.Info(SourceDataLine.class, format); // creates data line with class type and audio format.
SourceDataLine source = (SourceDataLine) AudioSystem.getLine(info);

System.out.println("Size of data line buffer: " + source.getBufferSize());

fileContent = new byte [source.getBufferSize() / 50];

byteoutput = new ByteArrayOutputStream();
input = AudioSystem.getAudioInputStream(file);

int readBytes = 0;
while ((readBytes = input.read(fileContent, 0, fileContent.length)) != -1) {
byteoutput.write(fileContent, 0, readBytes);
}
System.out.println("Size of audio buffer: " + fileContent.length);

//byteoutput.write(0);
// byteoutput.write(0);

System.out.println("Size of audio buffer: " + byteoutput.size());

source.open(format, source.getBufferSize()); // line must be open to be recognised by the mixer.

Line lines = mixer.getSourceLines();

System.out.println("mixer lines: " + lines.length);

// for(byte bytes: fileContent) {
// System.out.println(bytes);
// }

Thread playback = new Thread () {
public void run () {
// System.out.println((byteoutput.size() +2) % 4);
source.start(); // play (buffer originally empty)
source.write(byteoutput.toByteArray(), 0, byteoutput.size()); // write input bytes to output buffer
} // end run (to do).
}; // end thread action

playback.start(); // start thread
}
catch (LineUnavailableException lue) {
System.out.println(lue.getMessage());
}
catch (FileNotFoundException fnfe) {
System.out.println(fnfe.getMessage());
}
catch(IOException ioe) {
System.out.println(ioe.getMessage());
}
catch(UnsupportedAudioFileException uafe) {
System.out.println(uafe.getMessage());
}
}
}


new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, 44100, 16, 2, 4, 44100, false);

AudioSystem.getAudioFileTypes()

2 Answers
2

Whether or not you can load and play a 24-bit file is system dependent, afaik.

I use Audacity for conversions. You should be able import your file into Audacity and export it as 16-bit, stereo, little-endian, 44100 fps, and then load that export with Java's AudioInputStream.

AudioInputStream

What you hear when playing from Audacity or from Java should be pretty much identical (adjusting for volume). If not, the most likely reason probably pertains to a mistake or overlook in the code, which is very easy to do.

The use of a ByteOutputStream in your code is superfluous. Read from the AudioInputStream into a fixed-size byte array (size being the buffer length, I recommend trying 8 or 16 * 1024 bytes as a first try) and then use the SourceDataLine write method to ship that array.

ByteOutputStream

AudioInputStream

SourceDataLine

Following is code that works on my system for loading a playing a "CD Quality" wav called "a3.wav" that I have that is in the same directory as the Java class. You should be able to swap in your own 44100, 16-bit, stereo, little-endian wav file.

I've commented out an attempt to load and play a 24-bit wav file called "spoken8000_24.wav". That attempt gave me an IllegalArgumentException: No line matching interface SourceDataLine supporting format PCM_SIGNED 8000.0 Hz, 24 bit, stereo, 6 bytes/frame, little-endian is supported.

IllegalArgumentException

No line matching interface SourceDataLine supporting format PCM_SIGNED 8000.0 Hz, 24 bit, stereo, 6 bytes/frame, little-endian is supported.

I have to admit, I'm unclear if my system doesn't provide the needed line or if I might have coded the format incorrectly! My OS can certainly play the file. So I'm thinking there is a distinction between what an OS can do and what a "Mixer" on a given system provides to Java.

As a get-around, I just always convert everything to "CD Quality" format, as that seems to be the most widely supported.

public class TriggerSound_SDL extends JFrame
{
public TriggerSound_SDL()
{
JButton button = new JButton("Play Sound");
button.addActionListener(e -> new Thread(() -> playBuzzer()).start());
getContentPane().add(button);
}

private void playBuzzer()
{
try
{
URL url;
url = getClass().getResource("a3.wav");
// url = getClass().getResource("spoken8000_24.wav");
AudioInputStream ais = AudioSystem.getAudioInputStream(url);
System.out.println(ais.getFormat());

AudioFormat audioFmt;
// "CD Quality" 44100 fps, 16-bit, stereo, little endian
audioFmt = new AudioFormat(
AudioFormat.Encoding.PCM_SIGNED,
44100, 16, 2, 4, 44100, false);

// 8000 fps, 32-bit, stereo
// audioFmt = new AudioFormat(
// AudioFormat.Encoding.PCM_SIGNED,
// 8000, 24, 2, 6, 8000, false);

Info info = new DataLine.Info(SourceDataLine.class,
audioFmt);
SourceDataLine sdl = (SourceDataLine)AudioSystem.getLine(info);
int bufferSize = 16 * 1024;
byte buffer = new byte[bufferSize];
sdl.open(audioFmt, bufferSize);
sdl.start();

int numBytesRead = 0;

while((numBytesRead = ais.read(buffer)) != -1)
{
sdl.write(buffer, 0, numBytesRead);
}
}
catch (IOException | UnsupportedAudioFileException
| LineUnavailableException ex)
{
ex.printStackTrace();
}
}

private static void createAndShowGUI()
{
JFrame frame = new TriggerSound_SDL();
frame.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}

public static void main(String args)
{
SwingUtilities.invokeLater(() -> createAndShowGUI());
}
}


This code, with some small tweaks should let you at least test the different formats.

EDIT:
I'm seeing where your goal is to make a DAW!
In that case, you will want to convert the bytes to PCM data. Can I suggest you borrow some code from AudioCue? I basically wrote it to be a Clip-substitute, and part of that involved making the PCM data available for manipulation. Some techniques for mixing, playing back at different frequencies, multithreading can be found in it.

Thanks for all the advice guys. I will be getting rid of the ByteOutputStream and just use the AudioInputStream, I now understand what I was doing was unnecessary!! Thanks for the advice all! I have indeed tried using AudioCue but it is not low level enough for what I want to do!

One more thing guys. Previously, I created a multitrack media player which is using the Clip class. To play all the audio tracks together, I was looping through a list of Clips and playing them. However, this means that all tracks may be playing a tiny amount after each other due to the processing of the loop. Also, Clip class created a new thread per audio. I do not wants 100 threads running on 100 tracks, I want one thread for my audio output. I am still trying to work out how to start all tracks at the same time without a loop....(im guessing AudioCue have nailed the concurrent cues).

Does anyone know the best way to play multiple audio tracks in to one output? Do I need to route/bus all my audio tracks in to one output and somehow write all data from audio files in to one output buffer then play this output in a thread?

Thanks!!

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