3GPファイルからDTMF数字を検出する

Question

Javaを使用して3GPファイルからDTMF数字を検出する方法があるのだろうかと思っていました。

Answer 1

TarsosDSPを使用すると、DTMFをJavaでデコードできます。これの実装例はthis blogpostにあります。

3GPからオーディオをデコードする方法は、その中で使用されるオーディオコーデックによって異なります。

Answer 2

私はこのセンテンスの下にポストしようとしているコードにこのようなライブラリ "TarsosDSP"を使用することは可能ですか？

はいの場合はどうですか？

私は本当に興味があり、私は理解したい！

import java.io.IOException; 

import org.JMathStudio.DataStructure.Complex; 
import org.JMathStudio.DataStructure.Cell.Cell; 
import org.JMathStudio.DataStructure.Cell.CellTools; 
import org.JMathStudio.DataStructure.Vector.CVector; 
import org.JMathStudio.DataStructure.Vector.Vector; 
import org.JMathStudio.DataStructure.Vector.VectorStack; 
import org.JMathStudio.Exceptions.DimensionMismatchException; 
import org.JMathStudio.Exceptions.IllegalArgumentException; 
import org.JMathStudio.Exceptions.UnSupportedImageFormatException; 
import org.JMathStudio.SignalToolkit.GeneralTools.SignalUtilities; 
import org.JMathStudio.SignalToolkit.TransformTools.FourierSet.FFT1D; 
import org.JMathStudio.SignalToolkit.Utilities.SignalGenerator; 


public class DTMF_Demo { 
static int [] freqTableRow = { 
     697, 770, 852, 941 
} ; 

static int [] freqTableCol = { 
     1209, 1336, 1477 
} ; 

static char [][] dialKey = { 
    {'1', '2', '3'}, 
    {'4', '5', '6'}, 
    {'7', '8', '9'}, 
    {'*', '0', '#'} 
} ; 

static int fs = 4000 ;    // Sampling Rate 
static float noiseLevel = 0.2f ; // Amplitude of the noise signal before normalization 

private String dialKeyString ;  // The dial key sequence generated 

// This is the method that generate the dial key sequence signal 
public float [] dtmfDial() throws IllegalArgumentException 
{ 

    VectorStack numberStack = new VectorStack() ; // A temporary storage for a list of signal vectors 
    int totalLength = 0 ; // Total length of the dial key sequence signal generated 
    int row ;    // Row index into the frequency table 
    int col ;    // Column index into the frequency table 
    int length ;   // Length of a dial key signal 
    int numDigit ;   // Number of keys to generate for a dial key sequence 
    int pauseLength ;  // Length of pause signal 
    int i, j, k ;   // Looping variables 
    float normFactor ;  // Normalization factor for dial key sequence 

    normFactor = 2.0f + noiseLevel ; 
    dialKeyString = new String("") ; 



    numDigit = Math.round((float) (5.0f + Math.random() * 11.0f)) ; 


    for(i = 0; i < numDigit; i++) 
    { 
     row = Math.round((float) (Math.random() * 3.99 - 0.49)) ; 


     col = Math.round((float) (Math.random() * 2.99 - 0.49)) ; 


     length = Math.round((float) (fs/2 + Math.random() * 1.5 * fs)) ; 


     pauseLength = Math.round((float) (fs/4 + Math.random() * 0.75 * fs)) ; 



     Vector tone = SignalGenerator.cosine(freqTableRow[row], fs, 0.0f, length+pauseLength) ; 



     Vector tone2 = SignalGenerator.cosine(freqTableCol[col], fs, 0.0f, length+pauseLength) ; 



     Vector noise = SignalGenerator.random(length+pauseLength) ; 





     dialKeyString += dialKey[row][col] ; // Look up actual key dialed 



     totalLength += (length+pauseLength) ; 





     // Sum the two sinusoids with addition of noise 
     for(j = 0; j < length; j++) 
     { 
      tone.accessVectorBuffer()[j] += tone2.accessVectorBuffer()[j] ; 
      tone.accessVectorBuffer()[j] += ((2.0f * noiseLevel) * noise.accessVectorBuffer()[j] - noiseLevel); 
      tone.accessVectorBuffer()[j] /= normFactor ; 

     } 


     // Inject pause and noise signals 
     for(j = length; j < length + pauseLength; j++) 
     { 
      tone.accessVectorBuffer()[j] = ((2.0f * noiseLevel) * noise.accessVectorBuffer()[j] - noiseLevel) ; 
      tone.accessVectorBuffer()[j] /= normFactor ; 

     } 



     numberStack.addVector(tone) ; // Add the dial key signal into the stack of signal vectors 



    } 



    float [] dtmfSignal = new float[totalLength] ; // Array of floats to serve as the output dial key sequence signal 
    Vector [] numberVectorArray = numberStack.accessVectorArray(); 

    // Concatenate the dial key signals to form the output dial key sequence signal 
    k = 0 ; 
    for(i = 0; i < numberStack.size(); i++) 
    { 
     for(j = 0; j < numberVectorArray[i].length(); j++) 
     { 
      dtmfSignal[k] = numberVectorArray[i].accessVectorBuffer()[j] ; 



      k++ ; 
     } 
    } 


    return dtmfSignal ; 
} 



public Boolean dialKeyStringMatch(String decodedKeyString) 
{ 
    return dialKeyString.equals(decodedKeyString) ; 
} 



public String getDialString() 
{ 
    return dialKeyString ; 
} 




public static void main(String[] args) throws IOException, UnSupportedImageFormatException, DimensionMismatchException 
{ 
    // TODO Auto-generated method stub 
    DTMF_Demo demo = new DTMF_Demo() ; 
    DTMF_Decode decoder = new DTMF_Decode() ; 


    try 
    { 
     int correct = 0 ; 
     int totalCount = 1 ; 

     for(int i = 0; i < totalCount; i++) 
     { 
      // Generate Dial Key Sequence Signal 
      float [] dtmfSignal = demo.dtmfDial() ; 

      // Call your implemented dtmfAnalyse method and obtain decoded key string 
      String decodedKeyString = decoder.dtmfAnalyse(dtmfSignal, fs) ; 

      // Compare your decoded key sequence with the ground truth 
      if(demo.dialKeyStringMatch(decodedKeyString)) 
      { 
       correct++ ; 
      } 
      else 
      { 
       // Print out incorrectly decoded dial key sequence 
       System.out.println(demo.getDialString() + " (original) != " + decodedKeyString + " (decoded)") ; 
      } 







     } 

     System.out.println(correct + " out of " + totalCount + " are correct.") ; 

    } 
    catch (Exception e) 
    { 
     e.printStackTrace() ; 
    } 

} 

}