audio mixer lol

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import java.nio.ByteBuffer;
import java.io.ByteArrayInputStream;
import java.io.IOException;

public class AudioMixer {
    public static final AudioFormat STANDARD_FORMAT = new AudioFormat(44100, 16, 2, false, true);

    public AudioInputStream add (int length, AudioInputStream ais1, int start1, AudioInputStream ais2, int start2) {
        try {
            AudioInputStream aisc1;
            if (!AudioSystem.isConversionSupported(STANDARD_FORMAT, ais1.getFormat())) throw new IllegalArgumentException("incompatible formats");
            aisc1 = AudioSystem.getAudioInputStream(STANDARD_FORMAT, ais1);
            AudioInputStream aisc2;
            if (!AudioSystem.isConversionSupported(STANDARD_FORMAT, ais2.getFormat())) throw new IllegalArgumentException("incompatible formats");
            aisc2 = AudioSystem.getAudioInputStream(STANDARD_FORMAT, ais2);
            ByteBuffer buf = ByteBuffer.allocate(length * 2);
            for (int i = 0; i < length; i++) {
                int sum = 0;
                sum += ByteBuffer.wrap(aisc1.readNBytes(2)).getShort();
                sum += ByteBuffer.wrap(aisc2.readNBytes(2)).getShort();
                buf.putShort((short) (sum / 2));
            }
            return new AudioInputStream(new ByteArrayInputStream(buf.array()), STANDARD_FORMAT, length * 2);
        } catch (IOException ioe) {
            ioe.printStackTrace();
            return null;
        }
    }

    public AudioInputStream subtract (int length, AudioInputStream ais1, int start1, AudioInputStream ais2, int start2) {
        try {
            AudioInputStream aisc1;
            if (!AudioSystem.isConversionSupported(STANDARD_FORMAT, ais1.getFormat())) throw new IllegalArgumentException("incompatible formats");
            aisc1 = AudioSystem.getAudioInputStream(STANDARD_FORMAT, ais1);
            AudioInputStream aisc2;
            if (!AudioSystem.isConversionSupported(STANDARD_FORMAT, ais2.getFormat())) throw new IllegalArgumentException("incompatible formats");
            aisc2 = AudioSystem.getAudioInputStream(STANDARD_FORMAT, ais2);
            ByteBuffer buf = ByteBuffer.allocate(length * 2);
            for (int i = 0; i < length; i++) {
                int sum = 0;
                sum += ByteBuffer.wrap(aisc1.readNBytes(2)).getShort();
                sum -= ByteBuffer.wrap(aisc2.readNBytes(2)).getShort();
                buf.putShort((short) (Math.max(sum, 0) / 2));
            }
            return new AudioInputStream(new ByteArrayInputStream(buf.array()), STANDARD_FORMAT, length * 2);
        } catch (IOException ioe) {
            ioe.printStackTrace();
            return null;
        }
    }
}