1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/com/aurellem/capture/StdAudio.java	Tue Oct 25 11:55:55 2011 -0700
     1.3 @@ -0,0 +1,312 @@
     1.4 +package com.aurellem.capture;
     1.5 +
     1.6 +
     1.7 +/*************************************************************************
     1.8 + *  Compilation:  javac StdAudio.java
     1.9 + *  Execution:    java StdAudio
    1.10 + *  
    1.11 + *  Simple library for reading, writing, and manipulating .wav files.
    1.12 +
    1.13 + *
    1.14 + *  Limitations
    1.15 + *  -----------
    1.16 + *    - Does not seem to work properly when reading .wav files from a .jar file.
    1.17 + *    - Assumes the audio is monaural, with sampling rate of 44,100.
    1.18 + *
    1.19 + *************************************************************************/
    1.20 +
    1.21 +import java.applet.Applet;
    1.22 +import java.applet.AudioClip;
    1.23 +import java.io.ByteArrayInputStream;
    1.24 +import java.io.File;
    1.25 +import java.net.MalformedURLException;
    1.26 +import java.net.URL;
    1.27 +
    1.28 +import javax.sound.sampled.AudioFileFormat;
    1.29 +import javax.sound.sampled.AudioFormat;
    1.30 +import javax.sound.sampled.AudioInputStream;
    1.31 +import javax.sound.sampled.AudioSystem;
    1.32 +import javax.sound.sampled.SourceDataLine;
    1.33 +
    1.34 +/**
    1.35 + *  <i>Standard audio</i>. This class provides a basic capability for
    1.36 + *  creating, reading, and saving audio. 
    1.37 + *  <p>
    1.38 + *  The audio format uses a sampling rate of 44,100 (CD quality audio), 16-bit, monaural.
    1.39 + *
    1.40 + *  <p>
    1.41 + *  For additional documentation, see <a href="http://introcs.cs.princeton.edu/15inout">Section 1.5</a> of
    1.42 + *  <i>Introduction to Programming in Java: An Interdisciplinary Approach</i> by Robert Sedgewick and Kevin Wayne.
    1.43 + */
    1.44 +public final class StdAudio {
    1.45 +
    1.46 +    /**
    1.47 +     *  The sample rate - 44,100 Hz for CD quality audio.
    1.48 +     */
    1.49 +    public static final int SAMPLE_RATE = 44100;
    1.50 +
    1.51 +    //private static final int BYTES_PER_SAMPLE = 2;                // 16-bit audio
    1.52 +    //private static final int BITS_PER_SAMPLE = 16;                // 16-bit audio
    1.53 +    private static final double MAX_16_BIT = Short.MAX_VALUE;     // 32,767
    1.54 +    //private static final int SAMPLE_BUFFER_SIZE = 4096;
    1.55 +
    1.56 +
    1.57 +    private static SourceDataLine line;   // to play the sound
    1.58 +    private static byte[] buffer;         // our internal buffer
    1.59 +    private static int bufferSize = 0;    // number of samples currently in internal buffer
    1.60 +
    1.61 +    // not-instantiable
    1.62 +    private StdAudio() { }
    1.63 +
    1.64 +   
    1.65 +    // static initializer
    1.66 +    //static { init(); }
    1.67 +
    1.68 +    // open up an audio stream
    1.69 +    
    1.70 +    /*
    1.71 +    private static void init() {
    1.72 +        try {
    1.73 +            // 44,100 samples per second, 16-bit audio, mono, signed PCM, little Endian
    1.74 +            AudioFormat format = new AudioFormat((float) SAMPLE_RATE, BITS_PER_SAMPLE, 1, true, false);
    1.75 +            DataLine.Info info = new DataLine.Info(SourceDataLine.class, format);
    1.76 +
    1.77 +            line = (SourceDataLine) AudioSystem.getLine(info);
    1.78 +            
    1.79 +            // RLM: set to 1 and see what happens!
    1.80 +            line.open(format, SAMPLE_BUFFER_SIZE);
    1.81 +            //line.open(format, SAMPLE_BUFFER_SIZE * BYTES_PER_SAMPLE);
    1.82 +            
    1.83 +            // the internal buffer is a fraction of the actual buffer size, this choice is arbitrary
    1.84 +            // it gets divided because we can't expect the buffered data to line up exactly with when
    1.85 +            // the sound card decides to push out its samples.
    1.86 +            buffer = new byte[SAMPLE_BUFFER_SIZE * BYTES_PER_SAMPLE/3];
    1.87 +        } catch (Exception e) {
    1.88 +            System.out.println(e.getMessage());
    1.89 +            System.exit(1);
    1.90 +        }
    1.91 +
    1.92 +        // no sound gets made before this call
    1.93 +        line.start();
    1.94 +    }
    1.95 +    */
    1.96 +
    1.97 +
    1.98 +    /**
    1.99 +     * Close standard audio.
   1.100 +     */
   1.101 +    public static void close() {
   1.102 +        line.drain();
   1.103 +        line.stop();
   1.104 +    }
   1.105 +    
   1.106 +    /**
   1.107 +     * Write one sample (between -1.0 and +1.0) to standard audio. If the sample
   1.108 +     * is outside the range, it will be clipped.
   1.109 +     */
   1.110 +    public static void play(double in) {
   1.111 +
   1.112 +        // clip if outside [-1, +1]
   1.113 +        if (in < -1.0) in = -1.0;
   1.114 +        if (in > +1.0) in = +1.0;
   1.115 +
   1.116 +        // convert to bytes
   1.117 +        short s = (short) (MAX_16_BIT * in);
   1.118 +        buffer[bufferSize++] = (byte) s;
   1.119 +        buffer[bufferSize++] = (byte) (s >> 8);   // little Endian
   1.120 +
   1.121 +        // send to sound card if buffer is full        
   1.122 +        if (bufferSize >= buffer.length) {
   1.123 +            line.write(buffer, 0, buffer.length);
   1.124 +            bufferSize = 0;
   1.125 +        }
   1.126 +    }
   1.127 +
   1.128 +    /**
   1.129 +     * Write an array of samples (between -1.0 and +1.0) to standard audio. If a sample
   1.130 +     * is outside the range, it will be clipped.
   1.131 +     */
   1.132 +    public static void play(double[] input) {
   1.133 +        for (int i = 0; i < input.length; i++) {
   1.134 +            play(input[i]);
   1.135 +        }
   1.136 +    }
   1.137 +
   1.138 +    /**
   1.139 +     * Read audio samples from a file (in .wav or .au format) and return them as a double array
   1.140 +     * with values between -1.0 and +1.0.
   1.141 +     */
   1.142 +    public static double[] read(String filename) {
   1.143 +        byte[] data = readByte(filename);
   1.144 +        int N = data.length;
   1.145 +        double[] d = new double[N/2];
   1.146 +        for (int i = 0; i < N/2; i++) {
   1.147 +            d[i] = ((short) (((data[2*i+1] & 0xFF) << 8) + (data[2*i] & 0xFF))) / ((double) MAX_16_BIT);
   1.148 +        }
   1.149 +        return d;
   1.150 +    }
   1.151 +
   1.152 +
   1.153 +
   1.154 +
   1.155 +    /**
   1.156 +     * Play a sound file (in .wav or .au format) in a background thread.
   1.157 +     */
   1.158 +    public static void play(String filename) {
   1.159 +        URL url = null;
   1.160 +        try {
   1.161 +            File file = new File(filename);
   1.162 +            if (file.canRead()) url = file.toURI().toURL();
   1.163 +        }
   1.164 +        catch (MalformedURLException e) { e.printStackTrace(); }
   1.165 +        // URL url = StdAudio.class.getResource(filename);
   1.166 +        if (url == null) throw new RuntimeException("audio " + filename + " not found");
   1.167 +        AudioClip clip = Applet.newAudioClip(url);
   1.168 +        clip.play();
   1.169 +    }
   1.170 +
   1.171 +    /**
   1.172 +     * Loop a sound file (in .wav or .au format) in a background thread.
   1.173 +     */
   1.174 +    public static void loop(String filename) {
   1.175 +        URL url = null;
   1.176 +        try {
   1.177 +            File file = new File(filename);
   1.178 +            if (file.canRead()) url = file.toURI().toURL();
   1.179 +        }
   1.180 +        catch (MalformedURLException e) { e.printStackTrace(); }
   1.181 +        // URL url = StdAudio.class.getResource(filename);
   1.182 +        if (url == null) throw new RuntimeException("audio " + filename + " not found");
   1.183 +        AudioClip clip = Applet.newAudioClip(url);
   1.184 +        clip.loop();
   1.185 +    }
   1.186 +
   1.187 +
   1.188 +    // return data as a byte array
   1.189 +    private static byte[] readByte(String filename) {
   1.190 +        byte[] data = null;
   1.191 +        AudioInputStream ais = null;
   1.192 +        try {
   1.193 +            URL url = StdAudio.class.getResource(filename);
   1.194 +            ais = AudioSystem.getAudioInputStream(url);
   1.195 +            data = new byte[ais.available()];
   1.196 +            ais.read(data);
   1.197 +        }
   1.198 +        catch (Exception e) {
   1.199 +            System.out.println(e.getMessage());
   1.200 +            throw new RuntimeException("Could not read " + filename);
   1.201 +        }
   1.202 +
   1.203 +        return data;
   1.204 +    }
   1.205 +
   1.206 +
   1.207 +
   1.208 +    /**
   1.209 +     * Save the double array as a sound file (using .wav or .au format).
   1.210 +     */
   1.211 +    public static void save(String filename, double[] input) {
   1.212 +
   1.213 +        // assumes 44,100 samples per second
   1.214 +        // use 16-bit audio, mono, signed PCM, little Endian
   1.215 +        AudioFormat format = new AudioFormat(SAMPLE_RATE, 16, 1, true, false);
   1.216 +        byte[] data = new byte[2 * input.length];
   1.217 +        for (int i = 0; i < input.length; i++) {
   1.218 +            int temp = (short) (input[i] * MAX_16_BIT);
   1.219 +            data[2*i + 0] = (byte) temp;
   1.220 +            data[2*i + 1] = (byte) (temp >> 8);
   1.221 +        }
   1.222 +
   1.223 +        // now save the file
   1.224 +        try {
   1.225 +            ByteArrayInputStream bais = new ByteArrayInputStream(data);
   1.226 +            AudioInputStream ais = new AudioInputStream(bais, format, input.length);
   1.227 +            if (filename.endsWith(".wav") || filename.endsWith(".WAV")) {
   1.228 +                AudioSystem.write(ais, AudioFileFormat.Type.WAVE, new File(filename));
   1.229 +            }
   1.230 +            else if (filename.endsWith(".au") || filename.endsWith(".AU")) {
   1.231 +                AudioSystem.write(ais, AudioFileFormat.Type.AU, new File(filename));
   1.232 +            }
   1.233 +            else {
   1.234 +                throw new RuntimeException("File format not supported: " + filename);
   1.235 +            }
   1.236 +        }
   1.237 +        catch (Exception e) {
   1.238 +            System.out.println(e);
   1.239 +            System.exit(1);
   1.240 +        }
   1.241 +    }
   1.242 +    
   1.243 +    public static void save(String filename, byte[] data){
   1.244 +    	 // now save the file
   1.245 +        AudioFormat format = new AudioFormat(SAMPLE_RATE, 32, 1, true, false);
   1.246 +
   1.247 +        try {
   1.248 +            ByteArrayInputStream bais = new ByteArrayInputStream(data);
   1.249 +            AudioInputStream ais = new AudioInputStream(bais, format, data.length/2);
   1.250 +            if (filename.endsWith(".wav") || filename.endsWith(".WAV")) {
   1.251 +                AudioSystem.write(ais, AudioFileFormat.Type.WAVE, new File(filename));
   1.252 +            }
   1.253 +            else if (filename.endsWith(".au") || filename.endsWith(".AU")) {
   1.254 +                AudioSystem.write(ais, AudioFileFormat.Type.AU, new File(filename));
   1.255 +            }
   1.256 +            else {
   1.257 +                throw new RuntimeException("File format not supported: " + filename);
   1.258 +            }
   1.259 +        }
   1.260 +        catch (Exception e) {
   1.261 +            System.out.println(e);
   1.262 +            System.exit(1);
   1.263 +        }
   1.264 +    }
   1.265 +
   1.266 +    /*
   1.267 +    public static void save(String filename, Byte[] data){
   1.268 +   	 // now save the file
   1.269 +      save(filename, ArrayUtils.toPrimitive(data));
   1.270 +       
   1.271 +   }
   1.272 +   */
   1.273 +
   1.274 +   /***********************************************************************
   1.275 +    * sample test client
   1.276 +    ***********************************************************************/
   1.277 +
   1.278 +    // create a note (sine wave) of the given frequency (Hz), for the given
   1.279 +    // duration (seconds) scaled to the given volume (amplitude)
   1.280 +    private static double[] note(double hz, double duration, double amplitude) {
   1.281 +        int N = (int) (StdAudio.SAMPLE_RATE * duration);
   1.282 +        double[] a = new double[N+1];
   1.283 +        for (int i = 0; i <= N; i++)
   1.284 +            a[i] = amplitude * Math.sin(2 * Math.PI * i * hz / StdAudio.SAMPLE_RATE);
   1.285 +        return a;
   1.286 +    }
   1.287 +
   1.288 +    /**
   1.289 +     * Test client - play an A major scale to standard audio.
   1.290 +     */
   1.291 +    public static void main(String[] args) {
   1.292 +        
   1.293 +        // 440 Hz for 1 sec
   1.294 +        double freq = 440.0;
   1.295 +        for (int i = 0; i <= StdAudio.SAMPLE_RATE; i++) {
   1.296 +            StdAudio.play(0.5 * Math.sin(2*Math.PI * freq * i / StdAudio.SAMPLE_RATE));
   1.297 +        }
   1.298 +        
   1.299 +        // scale increments
   1.300 +        int[] steps = { 0, 2, 4, 5, 7, 9, 11, 12 };
   1.301 +        for (int i = 0; i < steps.length; i++) {
   1.302 +            double hz = 440.0 * Math.pow(2, steps[i] / 12.0);
   1.303 +            StdAudio.play(note(hz, 1.0, 0.5));
   1.304 +        }
   1.305 +
   1.306 +
   1.307 +        // need to call this in non-interactive stuff so the program doesn't terminate
   1.308 +        // until all the sound leaves the speaker.
   1.309 +        StdAudio.close(); 
   1.310 +
   1.311 +        // need to terminate a Java program with sound
   1.312 +        System.exit(0);
   1.313 +    }
   1.314 +}
   1.315 +