static long align(long bytes,
    int blockSize) 
{
        // prevent null pointers
        if (blockSize < = 1) {
            return bytes;
        }
        return bytes - (bytes % blockSize);
}

 static int align(int bytes,
    int blockSize) 
{
        // prevent null pointers
        if (blockSize < = 1) {
            return bytes;
        }
        return bytes - (bytes % blockSize);
}

 static long bytes2micros(AudioFormat format,
    long bytes) 
{
        return (long) (bytes / format.getFrameRate() * 1000000.0f / format.getFrameSize());
}

 static long bytes2millis(AudioFormat format,
    long bytes) 
{
        return (long) (bytes / format.getFrameRate() * 1000.0f / format.getFrameSize());
}

 static float dBToLinear(float dB) 
{
        float linear = (float) Math.pow(10.0, dB/20.0);
        return linear;
}

DB to linear scale conversion.

 static long frames2micros(AudioFormat format,
    long frames) 
{
        return (long) (((double) frames) / format.getFrameRate() * 1000000.0d);
}

 static  void getByteSwapped(byte[] b,
    int off,
    int len) 
{
        byte tempByte;
        for (int i = off; i <  (off+len); i+=2) {
            tempByte = b[i];
            b[i] = b[i+1];
            b[i+1] = tempByte;
        }
}

Swaps bytes.

 public static AudioInputStream getPCMConvertedAudioInputStream(AudioInputStream ais) 
{
        // we can't open the device for non-PCM playback, so we have
        // convert any other encodings to PCM here (at least we try!)
        AudioFormat af = ais.getFormat();
        if( (!af.getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)) &&
            (!af.getEncoding().equals(AudioFormat.Encoding.PCM_UNSIGNED))) {
            try {
                AudioFormat newFormat =
                    new AudioFormat( AudioFormat.Encoding.PCM_SIGNED,
                                     af.getSampleRate(),
                                     16,
                                     af.getChannels(),
                                     af.getChannels() * 2,
                                     af.getSampleRate(),
                                     Platform.isBigEndian());
                ais = AudioSystem.getAudioInputStream(newFormat, ais);
            } catch (Exception e) {
                if (Printer.err) e.printStackTrace();
                ais = null;
            }
        }
        return ais;
}

 static  void getUnsigned8(byte[] b,
    int off,
    int len) 
{
        for (int i = off; i <  (off+len); i++) {
            b[i] += 128;
        }
}

Converts bytes from signed to unsigned.

 static  void isFullySpecifiedAudioFormat(AudioFormat format) 
{
        if (!format.getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)
            && !format.getEncoding().equals(AudioFormat.Encoding.PCM_UNSIGNED)
            && !format.getEncoding().equals(AudioFormat.Encoding.ULAW)
            && !format.getEncoding().equals(AudioFormat.Encoding.ALAW)) {
            // we don't know how to verify possibly non-linear encodings
            return;
        }
        if (format.getFrameRate() < = 0) {
            throw new IllegalArgumentException("invalid frame rate: "
                                               +((format.getFrameRate()==-1)?
                                                 "NOT_SPECIFIED":String.valueOf(format.getFrameRate())));
        }
        if (format.getSampleRate() < = 0) {
            throw new IllegalArgumentException("invalid sample rate: "
                                               +((format.getSampleRate()==-1)?
                                                 "NOT_SPECIFIED":String.valueOf(format.getSampleRate())));
        }
        if (format.getSampleSizeInBits() < = 0) {
            throw new IllegalArgumentException("invalid sample size in bits: "
                                               +((format.getSampleSizeInBits()==-1)?
                                                 "NOT_SPECIFIED":String.valueOf(format.getSampleSizeInBits())));
        }
        if (format.getFrameSize() < = 0) {
            throw new IllegalArgumentException("invalid frame size: "
                                               +((format.getFrameSize()==-1)?
                                                 "NOT_SPECIFIED":String.valueOf(format.getFrameSize())));
        }
        if (format.getChannels() < = 0) {
            throw new IllegalArgumentException("invalid number of channels: "
                                               +((format.getChannels()==-1)?
                                                 "NOT_SPECIFIED":String.valueOf(format.getChannels())));
        }
}

 static boolean isFullySpecifiedPCMFormat(AudioFormat format) 
{
        if (!format.getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)
            && !format.getEncoding().equals(AudioFormat.Encoding.PCM_UNSIGNED)) {
            return false;
        }
        if ((format.getFrameRate() < = 0)
            || (format.getSampleRate() < = 0)
            || (format.getSampleSizeInBits() < = 0)
            || (format.getFrameSize() < = 0)
            || (format.getChannels() < = 0)) {
            return false;
        }
        return true;
}

 static float linearToDB(float linear) 
{
        float dB = (float) (Math.log((double)((linear==0.0)?0.0001:linear))/Math.log(10.0) * 20.0);
        return dB;
}

Linear to DB scale conversion.

 static long micros2bytes(AudioFormat format,
    long micros) 
{
        long result = (long) (micros * format.getFrameRate() / 1000000.0f * format.getFrameSize());
        return align(result, format.getFrameSize());
}

 static long micros2frames(AudioFormat format,
    long micros) 
{
        return (long) (micros * format.getFrameRate() / 1000000.0f);
}

 static long millis2bytes(AudioFormat format,
    long millis) 
{
        long result = (long) (millis * format.getFrameRate() / 1000.0f * format.getFrameSize());
        return align(result, format.getFrameSize());
}