Non hai bisogno di matematica e non hai bisogno di AudioRecord. Basta controllare MediaRecorder.getMaxAmplitude() ogni 1000 millisecondi.
this code e this code potrebbero essere utili.
Ecco un codice che è necessario.
public class Clapper
{
private static final String TAG = "Clapper";
private static final long DEFAULT_CLIP_TIME = 1000;
private long clipTime = DEFAULT_CLIP_TIME;
private AmplitudeClipListener clipListener;
private boolean continueRecording;
/**
* how much louder is required to hear a clap 10000, 18000, 25000 are good
* values
*/
private int amplitudeThreshold;
/**
* requires a little of noise by the user to trigger, background noise may
* trigger it
*/
public static final int AMPLITUDE_DIFF_LOW = 10000;
public static final int AMPLITUDE_DIFF_MED = 18000;
/**
* requires a lot of noise by the user to trigger. background noise isn't
* likely to be this loud
*/
public static final int AMPLITUDE_DIFF_HIGH = 25000;
private static final int DEFAULT_AMPLITUDE_DIFF = AMPLITUDE_DIFF_MED;
private MediaRecorder recorder;
private String tmpAudioFile;
public Clapper() throws IOException
{
this(DEFAULT_CLIP_TIME, "/tmp.3gp", DEFAULT_AMPLITUDE_DIFF, null, null);
}
public Clapper(long snipTime, String tmpAudioFile,
int amplitudeDifference, Context context, AmplitudeClipListener clipListener)
throws IOException
{
this.clipTime = snipTime;
this.clipListener = clipListener;
this.amplitudeThreshold = amplitudeDifference;
this.tmpAudioFile = tmpAudioFile;
}
public boolean recordClap()
{
Log.d(TAG, "record clap");
boolean clapDetected = false;
try
{
recorder = AudioUtil.prepareRecorder(tmpAudioFile);
}
catch (IOException io)
{
Log.d(TAG, "failed to prepare recorder ", io);
throw new RecordingFailedException("failed to create recorder", io);
}
recorder.start();
int startAmplitude = recorder.getMaxAmplitude();
Log.d(TAG, "starting amplitude: " + startAmplitude);
do
{
Log.d(TAG, "waiting while recording...");
waitSome();
int finishAmplitude = recorder.getMaxAmplitude();
if (clipListener != null)
{
clipListener.heard(finishAmplitude);
}
int ampDifference = finishAmplitude - startAmplitude;
if (ampDifference >= amplitudeThreshold)
{
Log.d(TAG, "heard a clap!");
clapDetected = true;
}
Log.d(TAG, "finishing amplitude: " + finishAmplitude + " diff: "
+ ampDifference);
} while (continueRecording || !clapDetected);
Log.d(TAG, "stopped recording");
done();
return clapDetected;
}
private void waitSome()
{
try
{
// wait a while
Thread.sleep(clipTime);
} catch (InterruptedException e)
{
Log.d(TAG, "interrupted");
}
}
/**
* need to call this when completely done with recording
*/
public void done()
{
Log.d(TAG, "stop recording");
if (recorder != null)
{
if (isRecording())
{
stopRecording();
}
//now stop the media player
recorder.stop();
recorder.release();
}
}
public boolean isRecording()
{
return continueRecording;
}
public void stopRecording()
{
continueRecording = false;
}
}
Controlla questo post: http://stackoverflow.com/questions/2257075/real-time-audio-processing-in-android – coder
Sì, ho letto sulla classe AudioRecord. Il metodo Read() di questa classe restituisce dati non elaborati, che devono essere analizzati utilizzando la matematica. Ma sto chiedendo se ci sono alcune API di terze parti per analizzare un suono senza matematica? – Elephant