CODEWITHSUNDEEP
javaaudio
dimmed
dimmed

Reputation: 47

Graphing wav file in java

I have been searching for this but none seems to answer my question. I have been trying to graph/plot a wav file by this:

int result = 0;
try {
    result = audioInputStream.read(bytes);
} catch (Exception e) {
    e.printStackTrace();
}

and then using the result to be a variable for a graph. I've been thinking if it is correct to change first the result to decibels. Also, am I right to use the result as a variable to be use in the graph? Or is there any way that has to be use in graphing the wav file?

Upvotes: 0

Views: 2159

Answers (1)

MadProgrammer
MadProgrammer

Reputation: 347334

The first thing you need to do is read the samples of the file, this will give you the min/max ranges of the waveform (sound wave)...

    File file = new File("...");
    AudioInputStream ais = null;
    try {
        ais = AudioSystem.getAudioInputStream(file);
        int frameLength = (int) ais.getFrameLength();
        int frameSize = (int) ais.getFormat().getFrameSize();
        byte[] eightBitByteArray = new byte[frameLength * frameSize];

        int result = ais.read(eightBitByteArray);

        int channels = ais.getFormat().getChannels();
        int[][] samples = new int[channels][frameLength];

        int sampleIndex = 0;
        for (int t = 0; t < eightBitByteArray.length;) {
            for (int channel = 0; channel < channels; channel++) {
                int low = (int) eightBitByteArray[t];
                t++;
                int high = (int) eightBitByteArray[t];
                t++;
                int sample = getSixteenBitSample(high, low);
                samples[channel][sampleIndex] = sample;
            }
            sampleIndex++;
        }

    } catch (Exception exp) {

        exp.printStackTrace();

    } finally {

        try {
            ais.close();
        } catch (Exception e) {
        }

    }

//...

protected int getSixteenBitSample(int high, int low) {
    return (high << 8) + (low & 0x00ff);
}

Then you would need to determine the min/max values, the next example simply checks for channel 0, but you could use the same concept to check all the available channels...

    int min = 0;
    int max = 0;
    for (int sample : samples[0]) {

        max = Math.max(max, sample);
        min = Math.min(min, sample);

    }

FYI: It would be more efficient to populate this information when you read the file

Once you have this, you can model the samples...but that would depend on framework you intend to use...

Upvotes: 4

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