Java中的正弦波聲音發生器

9

查看Beeper是一個獨立的例子。

也許更簡單的東西？

這51行代碼段（下面重複 - 單行&在行註釋隔開）作爲鏈接的答案頂部顯示，大約是生成音調一樣簡單得（OK，你可以爲諧波取出5行以上）。

人們似乎認爲它應該是內置於工具包中以產生純音的方法。它不是，並且需要一點點計算來製作一個。

/** Generates a tone, and assigns it to the Clip. */ 
public void generateTone() 
    throws LineUnavailableException { 
    if (clip!=null) { 
     clip.stop(); 
     clip.close(); 
    } else { 
     clip = AudioSystem.getClip(); 
    } 
    boolean addHarmonic = harmonic.isSelected(); 

    int intSR = ((Integer)sampleRate.getSelectedItem()).intValue(); 
    int intFPW = framesPerWavelength.getValue(); 

    float sampleRate = (float)intSR; 

    // oddly, the sound does not loop well for less than 
    // around 5 or so, wavelengths 
    int wavelengths = 20; 
    byte[] buf = new byte[2*intFPW*wavelengths]; 
    AudioFormat af = new AudioFormat(
     sampleRate, 
     8, // sample size in bits 
     2, // channels 
     true, // signed 
     false // bigendian 
     ); 

    int maxVol = 127; 
    for(int i=0; i<intFPW*wavelengths; i++){ 
     double angle = ((float)(i*2)/((float)intFPW))*(Math.PI); 
     buf[i*2]=getByteValue(angle); 
     if(addHarmonic) { 
      buf[(i*2)+1]=getByteValue(2*angle); 
     } else { 
      buf[(i*2)+1] = buf[i*2]; 
     } 
    } 

    try { 
     byte[] b = buf; 
     AudioInputStream ais = new AudioInputStream(
      new ByteArrayInputStream(b), 
      af, 
      buf.length/2); 

     clip.open(ais); 
    } catch(Exception e) { 
     e.printStackTrace(); 
    } 
}

來源

2011-12-25 23:33:54

+1

另請參閱['Note']（http://stackoverflow.com/a/2065693/230513）。 – trashgod 2011-12-26 01:50:51

7

使用Java Sound API和Math.sin創建實際的波動水平。

http://www.developer.com/java/other/article.php/2226701有一個很好的教程，圍繞這個，我前面引用過。 http://jsresources.org/examples/是另一個有用的參考。

來源

2011-12-25 23:23:27 ziesemer

+0

一些示例代碼會有所幫助，但我會盡力通過尋找有 – milo 2011-12-25 23:26:28

+0

的developer.com文章充滿了示例代碼。 – ziesemer 2011-12-26 01:10:16

6

如果你想一些簡單的代碼，讓你開始，這應有助於

import javax.sound.sampled.AudioFormat; 
import javax.sound.sampled.AudioSystem; 
import javax.sound.sampled.LineUnavailableException; 
import javax.sound.sampled.SourceDataLine; 

public class SinSynth { 
    // 
    protected static final int SAMPLE_RATE = 16 * 1024; 


    public static byte[] createSinWaveBuffer(double freq, int ms) { 
     int samples = (int)((ms * SAMPLE_RATE)/1000); 
     byte[] output = new byte[samples]; 
      // 
     double period = (double)SAMPLE_RATE/freq; 
     for (int i = 0; i < output.length; i++) { 
      double angle = 2.0 * Math.PI * i/period; 
      output[i] = (byte)(Math.sin(angle) * 127f); } 

     return output; 
    } 



    public static void main(String[] args) throws LineUnavailableException { 
     final AudioFormat af = new AudioFormat(SAMPLE_RATE, 8, 1, true, true); 
     SourceDataLine line = AudioSystem.getSourceDataLine(af); 
     line.open(af, SAMPLE_RATE); 
     line.start(); 

     boolean forwardNotBack = true; 

     for(double freq = 400; freq <= 800;) { 
      byte [] toneBuffer = createSinWaveBuffer(freq, 50); 
      int count = line.write(toneBuffer, 0, toneBuffer.length); 

      if(forwardNotBack) { 
       freq += 20; 
       forwardNotBack = false; } 
      else { 
       freq -= 10; 
       forwardNotBack = true; 
     } } 

     line.drain(); 
     line.close(); 
    } 

}

來源

2014-05-29 08:16:58 Thumbz

+0

這很容易閱讀，但魔術數字127f從哪裏來？ – nont 2017-08-29 19:22:38

+1

@nont sin返回-1.0到1.0的值，乘以127會得到一個正弦波，滿量程爲一個字節-127到+127，（它被轉換爲一個字節） – 2017-11-02 19:40:40

0

我只是想指出的是，有產生正弦波一個非常高效的算法。

DSP絕招：正弦音頻發生器 http://www.dspguru.com/dsp/tricks/sine_tone_generator

來源

2015-02-11 16:51:48

0

在第一個我建議創建類注意，這回注的頻率的頻道，並將其轉換爲字節數組。

然後流很伊斯利

protected static final int SAMPLE_RATE = 8 * 1024; 


    public static void main(String[] args) throws LineUnavailableException { 
     final AudioFormat af = new AudioFormat(SAMPLE_RATE, 8, 1, true, true); 
     SourceDataLine line = AudioSystem.getSourceDataLine(af); 
     line.open(af, SAMPLE_RATE); 
     line.start(); 

     // fist argument is duration of playing note 
     byte[] noteDo = Note.DO.getTone(1, SAMPLE_RATE); 
     byte[] noteRe = Note.RE.getTone(0.5, SAMPLE_RATE); 
     byte[] noteMi = Note.MI.getTone(1.5, SAMPLE_RATE); 

     line.write(noteDo, 0, noteDo.length); 
     line.write(noteRe, 0, noteRe.length); 
     line.write(noteMi, 0, noteMi.length); 

     line.drain(); 
     line.close(); 
    } 



public enum Note { 

    DO(0.0f), DO_DIEZ(1.0f), 
    RE(2.0f), RE_DIEZ(3.0f), 
    MI(4.0f), 
    FA(5.0f), FA_DIEZ(6.0f), 
    SOL(7.0f),SOL_DIEZ(8.0f), 
    LYA(9.0f),LYA_DIEZ(10.0f), 
    SI(11.0f); 


    private final double mPhase; 

    Note(double phase) { 
     mPhase = phase; 
    } 

    public double getNoteFrequencies() { 

     double index = getmPhase()/ 12.0d; 

     return 440 * Math.pow(2, index); 
    } 

    public static Note getNote(double phase) throws Exception { 

     Note findNote = null; 

     for (Note note : Note.values()){ 
      if (note.getmPhase() == phase){ 
       findNote = note; 
      } 
     } 

     if (findNote == null) 
      throw new Exception("Note not found: Ilegal phase " + phase); 
     else 
      return findNote; 
    } 

    public byte[] getTone(double duration, int rate){ 

     double frequencies = getNoteFrequencies(); 

     int maxLength = (int)(duration * rate); 
     byte generatedTone[] = new byte[2 * maxLength]; 

     double[] sample = new double[maxLength]; 
     int idx = 0; 

     for (int x = 0; x < maxLength; x++){ 
      sample[x] = sine(x, frequencies/rate); 
     } 


     for (final double dVal : sample) { 

      final short val = (short) ((dVal * 100f)); 

      // in 16 bit wav PCM, first byte is the low order byte 
      generatedTone[idx++] = (byte) (val & 0x00ff); 
      generatedTone[idx++] = (byte) ((val & 0xff00) >>> 8); 

     } 

     return generatedTone; 
    } 

    private double sine(int x, double frequencies){ 
     return Math.sin( 2*Math.PI * x * frequencies); 
    } 

    public double getmPhase() { 
     return mPhase; 
    } 
}

來源

2016-10-29 17:12:28

Java中的正弦波聲音發生器

回答

相關問題