How to get PCM data from a wav file?

Question

I have a .wav file. I want to get the PCM data from that sound file, so that I can get the individual data chunks from the sound and process it.

But I don't know how to do it. Can anyone tell me how to do it? I have done this so far:

public class test
{

    static int frameSample;
    static int timeofFrame;
    static int N;
    static int runTimes;
    static int bps;
    static int channels;
    static double times;
    static int bufSize;
    static int frameSize;
    static int frameRate;
    static long length;

    public static void main(String[] args)
    {
        try
        {
            AudioInputStream ais = AudioSystem.getAudioInputStream(new File("music/audio.wav"));
            AudioInputStream a;
            int numBytes = ais.available();
            System.out.println("numbytes: "+numBytes);
            byte[] buffer = new byte[numBytes];
            byte[] buffer1=new byte[numBytes] ;
            int k=0;
            int count=0;
            while(count!=-1){
                count=ais.read(buffer, 0, numBytes);
            }
            long value = 0;

            for (int i = 0; i < buffer.length; i++)
            {
               value = ((long) buffer[i] & 0xffL) << (8 * i);
               System.out.println("value: "+value);
            }
        } catch(Exception e) {

        }
    }
}

Do you want to do this using Java or J? I head never heard of 'J' before your question, and suspect you mean Java. — Andrew Thompson, Aug 25 '12 at 09:13
sorry. i did not mean j. i want to do it in java. sorry again. — Pallab, Aug 25 '12 at 10:34

score 6 · Answer 1 · edited May 23 '17 at 12:08

6

This can be done with the Java Sound API.

Use the AudioSystem to get an AudioInputStream from the file.
Query the stream for the AudioFormat.
Create a byte[] to suit the format. E.G. 8 bit mono is a byte[1]. 16 bit stereo is byte[4].
Read the stream in chunks of the byte[] and it will contain the sound, frame by frame.
Proceed with further processing..

edited May 23 '17 at 12:08

Community

1
1

answered Aug 25 '12 at 12:07

Andrew Thompson

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i have done this so far. is this correct? i want to collect the integer values from the bytes. the code is with the question. – Pallab Aug 26 '12 at 18:54
Please use a consistent and logical indent for code blocks. Note that the frames are 'individual data chunks' so your question has been answered. You should ask a separate question as to how to turn the frames into an int (mono) or a pair of ints (stereo). – Andrew Thompson Aug 26 '12 at 23:13
would you please tell me how can i seperate the header from the wav? please let me know. – Pallab Aug 27 '12 at 06:26
The bytes read from an `AudioInputStream` are pure sound data, there is no need to ignore any of them. But why should I keep trying to help, when you ignore advice about code formatting etc.? – Andrew Thompson Aug 27 '12 at 07:51

score 0 · Answer 2 · answered Nov 20 '21 at 23:15

Here is a fully working example using the javax.sound.sampled package. If you need details on the audio format you can get them via audioInputStream.getFormat() which will return a AudioFormat object.

public static byte[] getPcmByteArray(String filename) throws UnsupportedAudioFileException, IOException {

    ByteArrayOutputStream baos = new ByteArrayOutputStream(65536);
    File inputFile = new File(filename);
    AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(inputFile);

    byte[] buffer = new byte[4096];
    int bytesRead;
    while ((bytesRead = audioInputStream.read(buffer)) != -1) {
        baos.write(buffer, 0, bytesRead);
    }

    return baos.toByteArray();
}

How to get PCM data from a wav file?

2 Answers2

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