Mit Android einen beliebigen Ton spielen

Gibt es eine Möglichkeit, Android dazu zu bringen, einen Sound mit beliebiger Frequenz zu senden (dh ich möchte keine aufgezeichneten Sounddateien haben)?

Ich habe mich umgesehen und ToneGenerator war das einzige, was ich finden konnte, das sogar nahe war, aber es scheint nur in der Lage zu sein, die Standard-DTMF-Töne auszugeben.

Irgendwelche Ideen?

Ich habe diesen Beispielcode ursprünglich in einem Blog gefunden, aber er enthielt einige Fehler, die einige schreckliche Geräusche erzeugten. Ich habe die Fehler behoben und den resultierenden Code hier gepostet. Scheint gut für mich zu funktionieren!

public class PlaySound extends Activity {
    // originally from http://marblemice.blogspot.com/2010/04/generate-and-play-tone-in-android.html
    // and modified by Steve Pomeroy <steve@staticfree.info>
    private final int duration = 3; // seconds
    private final int sampleRate = 8000;
    private final int numSamples = duration * sampleRate;
    private final double sample[] = new double[numSamples];
    private final double freqOfTone = 440; // hz

    private final byte generatedSnd[] = new byte[2 * numSamples];

    Handler handler = new Handler();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    @Override
    protected void onResume() {
        super.onResume();

        // Use a new tread as this can take a while
        final Thread thread = new Thread(new Runnable() {
            public void run() {
                genTone();
                handler.post(new Runnable() {

                    public void run() {
                        playSound();
                    }
                });
            }
        });
        thread.start();
    }

    void genTone(){
        // fill out the array
        for (int i = 0; i < numSamples; ++i) {
            sample[i] = Math.sin(2 * Math.PI * i / (sampleRate/freqOfTone));
        }

        // convert to 16 bit pcm sound array
        // assumes the sample buffer is normalised.
        int idx = 0;
        for (final double dVal : sample) {
            // scale to maximum amplitude
            final short val = (short) ((dVal * 32767));
            // in 16 bit wav PCM, first byte is the low order byte
            generatedSnd[idx++] = (byte) (val & 0x00ff);
            generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);

        }
    }

    void playSound(){
        final AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                sampleRate, AudioFormat.CHANNEL_OUT_MONO,
                AudioFormat.ENCODING_PCM_16BIT, generatedSnd.length,
                AudioTrack.MODE_STATIC);
        audioTrack.write(generatedSnd, 0, generatedSnd.length);
        audioTrack.play();
    }
}

Verbesserung des obigen Codes:

Fügen Sie die Amplitudenrampe hoch und runter, um Klicks zu vermeiden.

Fügen Sie Code hinzu, um festzustellen, wann der Tack beendet ist.

double duration = 1;            // seconds
double freqOfTone = 1000;       // hz
int sampleRate = 8000;          // a number

double dnumSamples = duration * sampleRate;
dnumSamples = Math.ceil(dnumSamples);
int numSamples = (int) dnumSamples;
double sample[] = new double[numSamples];
byte generatedSnd[] = new byte[2 * numSamples];


for (int i = 0; i < numSamples; ++i) {    // Fill the sample array
    sample[i] = Math.sin(freqOfTone * 2 * Math.PI * i / (sampleRate));
}

// convert to 16 bit pcm sound array
// assumes the sample buffer is normalized.
// convert to 16 bit pcm sound array
// assumes the sample buffer is normalised.
int idx = 0;
int i = 0 ;

int ramp = numSamples / 20 ;                                     // Amplitude ramp as a percent of sample count


for (i = 0; i< ramp; ++i) {                                      // Ramp amplitude up (to avoid clicks)
    double dVal = sample[i];
                                                                 // Ramp up to maximum
    final short val = (short) ((dVal * 32767 * i/ramp));
                                                                 // in 16 bit wav PCM, first byte is the low order byte
    generatedSnd[idx++] = (byte) (val & 0x00ff);
    generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
}


for (i = i; i< numSamples - ramp; ++i) {                         // Max amplitude for most of the samples
    double dVal = sample[i];
                                                                 // scale to maximum amplitude
    final short val = (short) ((dVal * 32767));
                                                                 // in 16 bit wav PCM, first byte is the low order byte
    generatedSnd[idx++] = (byte) (val & 0x00ff);
    generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
}

for (i = i; i< numSamples; ++i) {                                // Ramp amplitude down
    double dVal = sample[i];
                                                                 // Ramp down to zero
    final short val = (short) ((dVal * 32767 * (numSamples-i)/ramp ));
                                                                 // in 16 bit wav PCM, first byte is the low order byte
    generatedSnd[idx++] = (byte) (val & 0x00ff);
    generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
}

AudioTrack audioTrack = null;                                    // Get audio track
try {
    audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
        sampleRate, AudioFormat.CHANNEL_CONFIGURATION_MONO,
        AudioFormat.ENCODING_PCM_16BIT, (int)numSamples*2,
        AudioTrack.MODE_STATIC);
    audioTrack.write(generatedSnd, 0, generatedSnd.length);        // Load the track
    audioTrack.play();                                             // Play the track
}
catch (Exception e){
    RunTimeError("Error: " + e);
    return false;
}

int x =0;
do{                                                              // Monitor playback to find when done
    if (audioTrack != null) 
        x = audioTrack.getPlaybackHeadPosition(); 
    else 
        x = numSamples;
} while (x<numSamples);

if (audioTrack != null) audioTrack.release();                    // Track play done. Release track.

Ich habe die oben genannten wunderbaren Lösungen in ein hübsches kleines Paket verpackt, das sofort als einfacher konfigurierbarer Summer verwendet werden kann. Es wird in einem Hintergrundthread ausgeführt und verfügt über Stop-and-Play-Methoden und eine Handvoll Optionen, die Sie festlegen können.

Es ist in JCenter verfügbar, sodass Sie es wie folgt zu Ihrer Abhängigkeitsliste hinzufügen können

compile 'net.mabboud:android-tone-player:0.2'

und Sie verwenden es so für einen kontinuierlichen Summer

ContinuousBuzzer tonePlayer = new ContinuousBuzzer();
tonePlayer.play();

// just an example don't actually use Thread.sleep in your app
Thread.sleep(1000); 
tonePlayer.stop();

oder ein Summer wird nur einmal gespielt und Sie können Frequenz und Lautstärke so einstellen

OneTimeBuzzer buzzer = new OneTimeBuzzer();
buzzer.setDuration(5);

// volume values are from 0-100
buzzer.setVolume(50);
buzzer.setToneFreqInHz(110);

Erweiterter Blog-Beitrag hier darüber hier GitHub hier

Da es in einigen älteren Android-Versionen einen Fehler gibt, der bei Verwendung von MODE_STATIC einen Speicherverlust verursacht, habe ich die Antwort von Xarph oben geändert, um MODE_STREAM zu verwenden. Hoffentlich hilft es einigen.

public void playTone(double freqOfTone, double duration) {
 //double duration = 1000;                // seconds
 //   double freqOfTone = 1000;           // hz
    int sampleRate = 8000;              // a number

    double dnumSamples = duration * sampleRate;
    dnumSamples = Math.ceil(dnumSamples);
    int numSamples = (int) dnumSamples;
    double sample[] = new double[numSamples];
    byte generatedSnd[] = new byte[2 * numSamples];


    for (int i = 0; i < numSamples; ++i) {      // Fill the sample array
        sample[i] = Math.sin(freqOfTone * 2 * Math.PI * i / (sampleRate));
    }

    // convert to 16 bit pcm sound array
    // assumes the sample buffer is normalized.
    // convert to 16 bit pcm sound array
    // assumes the sample buffer is normalised.
    int idx = 0;
    int i = 0 ;

    int ramp = numSamples / 20 ;                                    // Amplitude ramp as a percent of sample count


    for (i = 0; i< ramp; ++i) {                                     // Ramp amplitude up (to avoid clicks)
        double dVal = sample[i];
                                                                    // Ramp up to maximum
        final short val = (short) ((dVal * 32767 * i/ramp));
                                                                    // in 16 bit wav PCM, first byte is the low order byte
        generatedSnd[idx++] = (byte) (val & 0x00ff);
        generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
    }


    for (i = i; i< numSamples - ramp; ++i) {                        // Max amplitude for most of the samples
        double dVal = sample[i];
                                                                    // scale to maximum amplitude
        final short val = (short) ((dVal * 32767));
                                                                    // in 16 bit wav PCM, first byte is the low order byte
        generatedSnd[idx++] = (byte) (val & 0x00ff);
        generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
    }

    for (i = i; i< numSamples; ++i) {                               // Ramp amplitude down
        double dVal = sample[i];
                                                                    // Ramp down to zero
        final short val = (short) ((dVal * 32767 * (numSamples-i)/ramp ));
                                                                    // in 16 bit wav PCM, first byte is the low order byte
        generatedSnd[idx++] = (byte) (val & 0x00ff);
        generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
    }

    AudioTrack audioTrack = null;                                   // Get audio track
    try {
         int bufferSize = AudioTrack.getMinBufferSize(sampleRate, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
        audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                sampleRate, AudioFormat.CHANNEL_OUT_MONO,
                AudioFormat.ENCODING_PCM_16BIT, bufferSize,
                AudioTrack.MODE_STREAM);
        audioTrack.play();                                          // Play the track
        audioTrack.write(generatedSnd, 0, generatedSnd.length);     // Load the track
    }
    catch (Exception e){
    }
    if (audioTrack != null) audioTrack.release();           // Track play done. Release track.
}

Hier ist ein weiteres Blog, das einen einfachen Synthesizer und eine Benutzeroberfläche vorführt

http://audioprograming.wordpress.com/2012/10/18/a-simple-synth-in-android-step-by-step-guide-using-the-java-sdk/

Sie könnten auch an csound oder pdlib (pure data lib) für Android interessiert sein.

Geänderter Code Basierend auf Singhaks Antwort

public class MainActivity extends Activity {
    private final int duration = 30; // seconds
    private final int sampleRate = 8000;
    private final int numSamples = duration * sampleRate;
    private final double sample[] = new double[numSamples];
    private final double freqOfTone = 440; // hz
    private final byte generatedSnd[] = new byte[2 * numSamples];
    Handler handler = new Handler();
    private AudioTrack audioTrack;
    private boolean play = false;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                8000, AudioFormat.CHANNEL_OUT_MONO,
                AudioFormat.ENCODING_PCM_16BIT, numSamples,
                AudioTrack.MODE_STREAM);
    }

    @Override
    protected void onResume() {
        super.onResume();

        // Use a new tread as this can take a while
        Thread thread = new Thread(new Runnable() {
            public void run() {

                handler.post(new Runnable() {

                    public void run() {
                        playSound();
                        genTone();
                    }
                });
            }   
        });
        thread.start();
    }

    void genTone(){
        // fill out the array
        while(play){
                for (int i = 0; i < numSamples; ++i) {
                //  float angular_frequency = 
                    sample[i] = Math.sin(2 * Math.PI * i / (sampleRate/freqOfTone));
                }
                int idx = 0;

                // convert to 16 bit pcm sound array
                // assumes the sample buffer is normalised.
                for (double dVal : sample) {
                    short val = (short) (dVal * 32767);
                    generatedSnd[idx++] = (byte) (val & 0x00ff);
                    generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
                }
                audioTrack.write(generatedSnd, 0, numSamples);
            }
        }


    void playSound(){
        play = true;
        audioTrack.play();
    }
}

    float synth_frequency = 440;
    int minSize = AudioTrack.getMinBufferSize(SAMPLE_RATE,
AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT);
AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
SAMPLE_RATE,
AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT,
minSize,
AudioTrack.MODE_STREAM);
audioTrack.play();
short[] buffer = new short[minSize];
float angle = 0;
while (true) 
{
    if (play)
    {
        for (int i = 0; i < buffer.length; i++)
        {
            float angular_frequency =
            (float)(2*Math.PI) * synth_frequency / SAMPLE_RATE;
            buffer[i] = (short)(Short.MAX_VALUE * ((float) Math.sin(angle)));
            angle += angular_frequency;
    }
        audioTrack.write(buffer, 0, buffer.length);
    } 

// Sie können einen beliebigen Wert in synth_frequency hinzufügen, um Änderungssound zu erhalten. Sie können beispielsweise eine Zufallsvariable hinzufügen, um Sound zu erhalten

Do major (16 Noten)

 public class MainActivity extends AppCompatActivity {

  private double mInterval = 0.125;
  private int mSampleRate = 8000;
  private byte[] generatedSnd;

  private final double mStandardFreq = 440;

  Handler handler = new Handler();
  private AudioTrack audioTrack;


  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }

  @Override
  protected void onResume() {
    super.onResume();

    // Use a new tread as this can take a while
    final Thread thread = new Thread(new Runnable() {
        public void run() {

            byte[] tempByte = new byte[0];
            for (int i = 0; i < 16 ; i++ ){
                double note = getNoteFrequencies(i);
                byte[] tonByteNote = getTone(mInterval, mSampleRate, note);
                tempByte = concat(tonByteNote, tempByte);
            }
            generatedSnd = tempByte;

            handler.post(new Runnable() {
                public void run() {
                    playTrack(generatedSnd);
                }
            });
        }
    });
    thread.start();
  }

  public byte[] concat(byte[] a, byte[] b) {
    int aLen = a.length;
    int bLen = b.length;
    byte[] c= new byte[aLen+bLen];
    System.arraycopy(a, 0, c, 0, aLen);
    System.arraycopy(b, 0, c, aLen, bLen);
    return c;
  }

  private double getNoteFrequencies(int index){
    return mStandardFreq * Math.pow(2, (double) index/12.0d);
  }

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

    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 * 32767));

        // 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 AudioTrack getAudioTrack(int length){

    if (audioTrack == null)
        audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                mSampleRate, AudioFormat.CHANNEL_OUT_MONO,
                AudioFormat.ENCODING_PCM_16BIT, length,
                AudioTrack.MODE_STATIC);

    return audioTrack;
  }

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

  void playTrack(byte[] generatedSnd){
    getAudioTrack(generatedSnd.length)
            .write(generatedSnd, 0, generatedSnd.length);
    audioTrack.play();
  }

}

siehe diese hilfreiche Bibliothek

https://github.com/karlotoy/perfectTune

es ist einfach zu bedienen

Fügen Sie dies Ihren Abhängigkeiten hinzu

 compile 'com.github.karlotoy:perfectTune:1.0.2'

Und du benutzt es so:

PerfectTune perfectTune = new PerfectTune();
perfectTune.setTuneFreq(desire_freq);
perfectTune.playTune();

um die Melodie zu stoppen:

perfectTune.stopTune();

Es gibt mehrere Programme dafür, aber sie saugen. Ich habe ein paar gemessen:

http://www.endolith.com/wordpress/2009/11/24/android-audio-applications/

Also tu nicht was sie tun. : D.