/*
* The MIT License (MIT)
*
* Copyright (c) 2015 Tinotenda Chemvura
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.tino1b2be.dtmfdecoder;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import javax.sound.sampled.UnsupportedAudioFileException;
import org.apache.commons.math3.complex.Complex;
import org.apache.commons.math3.transform.DftNormalization;
import org.apache.commons.math3.transform.FastFourierTransformer;
import org.apache.commons.math3.transform.TransformType;
import com.tino1b2be.audio.AudioFile;
import com.tino1b2be.audio.AudioFileException;
import com.tino1b2be.audio.TempAudio;
import com.tino1b2be.audio.WavFileException;
/**
* Class to decode DTMF signals in a supported audio file.
*
* @author Tinotenda Chemvura
*
*/
public class DTMFUtil {
/**
* True if the decoder is to be used in debug mode. False by default
*/
public static boolean debug = false;
/**
* True if decoder is to use the goertzel algorithm instead of the FFT False
* by default
*/
public static boolean goertzel = false;
private static final double CUT_OFF_POWER = 0.004;
private static final double FFT_CUT_OFF_POWER_NOISE_RATIO = 0.46;
private static final double FFT_FRAME_DURATION = 0.030;
private static final double GOERTZEL_CUT_OFF_POWER_NOISE_RATIO = 0.87;
private static final double GOERTZEL_FRAME_DURATION = 0.045;
private boolean decoded;
private static boolean decode60 = false;
private static boolean decode80 = false;
private static boolean decode100 = false;
private boolean decoder = false;
private boolean generate = false;
private String seq[];
private AudioFile audio;
private int frameSize;
private static int[] freqIndicies;
/**
* The list of valid DTMF frequencies that are going to be processed and
* searched for within the ITU-T recommendations . See the <a href=
* "http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling" >
* WikiPedia article on DTMF</a>.
*/
public static final int[] DTMF_FREQUENCIES_BIN = {
687, 697, 707, // 697
758, 770, 782, // 770
839, 852, 865, // 852
927, 941, 955, // 941
1191, 1209, 1227, // 1209
1316, 1336, 1356, // 1336
1455, 1477, 1499, // 1477
1609, 1633, 1647, 1657 // 1633
};
/**
* The list of valid DTMF frequencies. See the <a href=
* "http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling" >
* WikiPedia article on DTMF</a>.
*/
public static final int[] DTMF_FREQUENCIES = { 697, 770, 852, 941, 1209, 1336, 1477, 1633 };
/**
* The list of valid DTMF characters. See the <a href=
* "http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling" >
* WikiPedia article on DTMF</a>.
*/
public static final char[] DTMF_CHARACTERS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
'A', 'B', 'C', 'D' };
// generation variables
private double[] generatedSeq;
private int outPauseDurr;
private int outToneDurr;
private double outFs;
private File outFile;
private char[] outChars;
private boolean generated;
/**
* Constructor to decode an array of samples
*
* @param samples
* array of samples (Mono channel)
* @param Fs
* Sampling Frequency
* @throws AudioFileException
* @throws DTMFDecoderException
*/
public DTMFUtil(double[] samples, int Fs) throws AudioFileException, DTMFDecoderException {
// create an audio file object and export to a temp location
// load the temp audio file and decode
this.decoder = true;
audio = new TempAudio(samples, Fs);
setFrameSize();
setCentreIndicies();
this.decoded = false;
seq = new String[2];
this.seq[0] = "";
this.seq[1] = "";
}
/**
* Constructor to decode an array of samples
*
* @param samples
* array of samples (Stereo channel)
* @param Fs
* Sampling Frequency
* @throws AudioFileException
* @throws DTMFDecoderException
*/
public DTMFUtil(double[][] samples, int Fs) throws AudioFileException, DTMFDecoderException {
// create an audio file object and export to a temp location
// load the temp audio file and decode
this.decoder = true;
audio = new TempAudio(samples, Fs);
setFrameSize();
setCentreIndicies();
this.decoded = false;
seq = new String[2];
this.seq[0] = "";
this.seq[1] = "";
}
/**
* Constructor used to Decode an audio file
*
* @param data
* AudioFile object to be processed.
* @throws DTMFDecoderException
*/
public DTMFUtil(AudioFile data) throws DTMFDecoderException {
this.decoder = true;
this.audio = data;
setFrameSize();
if (!goertzel)
setCentreIndicies();
this.decoded = false;
seq = new String[2];
this.seq[0] = "";
this.seq[1] = "";
}
/**
* Constructor used to Decode an audio file
*
* @param filename
* Filename of the audio file to be processed
* @throws Exception
* @throws AudioFileException
* @throws UnsupportedAudioFileException
* @throws IOException
* @throws WavFileException
* @throws DTMFDecoderException
*/
public DTMFUtil(String filename) throws AudioFileException, IOException, DTMFDecoderException {
this.decoder = true;
this.audio = FileUtil.readAudioFile(filename);
setFrameSize();
if (!goertzel)
setCentreIndicies();
this.decoded = false;
seq = new String[2];
this.seq[0] = "";
this.seq[1] = "";
}
/**
* Constructor used to Decode an audio file
*
* @param file
* File object for the audio file
* @throws Exception
* @throws AudioFileException
* @throws UnsupportedAudioFileException
* @throws IOException
* @throws WavFileException
* @throws DTMFDecoderException
*/
public DTMFUtil(File file) throws AudioFileException, IOException, DTMFDecoderException {
this.decoder = true;
this.audio = FileUtil.readAudioFile(file);
setFrameSize();
if (!goertzel)
setCentreIndicies();
this.decoded = false;
seq = new String[2];
this.seq[0] = "";
this.seq[1] = "";
}
/**
* Constructor to be used to generate a sequence of DTMF tones.
*
* @param file
*
* @param chars
* Array with the sequence of DTMF characters.
* @param Fs
* Sampling Frequency
* @param toneDurr
* Duration of a tone.
* @param pauseDurr
* Duration of a pause
* @throws DTMFDecoderException
* If the given characters are not valid DTMF characters
*/
public DTMFUtil(File file, char[] chars, int fs, int toneDurr, int pauseDurr) throws DTMFDecoderException {
this.generate = true;
setChars(chars);
if (fs < 8000)
throw new DTMFDecoderException("Sampling frequency must be at least 8kHz.");
this.outFs = fs;
if (toneDurr < 40)
throw new DTMFDecoderException("Tone duration should be greater than 40ms.");
this.outToneDurr = toneDurr;
if (toneDurr < 30)
throw new DTMFDecoderException("Pause duration should be greater than 30ms.");
this.outPauseDurr = pauseDurr;
this.outFile = file;
}
/**
* Constructor to be used to generate a sequence of DTMF tones.
*
* @param file
*
* @param chars
* Array with the sequence of DTMF characters.
* @param Fs
* Sampling Frequency
* @param toneDurr
* Duration of a tone.
* @param pauseDurr
* Duration of a pause
* @throws DTMFDecoderException
* If the given characters are not valid DTMF characters
*/
public DTMFUtil(String filename, char[] chars, int fs, int toneDurr, int pauseDurr) throws DTMFDecoderException {
this.generate = true;
setChars(chars);
this.outFs = fs;
this.outToneDurr = toneDurr;
this.outPauseDurr = pauseDurr;
this.outFile = new File(filename);
}
/**
* Check if the characters are valid and set the characters
*
* @param chars
* Characters to be generated
* @throws DTMFDecoderException
*/
private void setChars(char[] chars) throws DTMFDecoderException {
outChars = new char[chars.length];
char[] cc = Arrays.copyOf(DTMF_CHARACTERS, DTMF_CHARACTERS.length);
Arrays.sort(cc);
for (int c = 0; c < chars.length; c++) {
if (Arrays.binarySearch(cc, chars[c]) < 0)
throw new DTMFDecoderException("The character \"" + chars[c] + "\" is not a DTMF character.");
else
outChars[c] = chars[c];
}
}
/**
* Method to precalculate the indices to be used to locate the DTMF
* frequencies in the power spectrum
*/
private void setCentreIndicies() {
freqIndicies = new int[DTMF_FREQUENCIES_BIN.length];
for (int i = 0; i < freqIndicies.length; i++) {
int ind = (int) Math.round(((DTMF_FREQUENCIES_BIN[i] * 1.0) / (audio.getSampleRate()) * 1.0) * frameSize);
freqIndicies[i] = ind;
}
}
/**
* Method to set the frame size for the decoding process. Framesize must be
* a power of 2
*
* @throws DTMFDecoderException
* If Fs if less than 8kHz or loo large.
*/
private void setFrameSize() throws DTMFDecoderException {
if (audio.getSampleRate() < 8000)
throw new DTMFDecoderException("Sampling Rate cannot be less than 8kHz.");
if (goertzel) {
this.frameSize = (int) Math.floor(GOERTZEL_FRAME_DURATION * audio.getSampleRate());
} else {
int size = 0;
for (int i = 8; i <= 15; i++) {
size = (int) Math.pow(2, i);
if (size / (audio.getSampleRate() * 1.0) < FFT_FRAME_DURATION)
continue;
else {
frameSize = size;
return;
}
}
throw new DTMFDecoderException(
"Sampling Frequency of the audio file is too high. Please use a file with a lower Sampling Frequency.");
}
}
/**
* Method to filter out the power spectrum information for the DTMF
* frequencies given an array of power spectrum information from an FFT.
*
* @param frame
* Frame with power spectrum information to be processed
* @return an array with 8 doubles. Each representing the magnitude of the
* corresponding dtmf frequency
*/
private static double[] filterFrame(double[] frame) {
double[] out = new double[8];
// 687, 697, 707, // 697 0,1,2
// 758, 770, 782, // 770 3,4,5
// 839, 852, 865, // 852 6,7,8
// 927, 941, 955, // 941 9,10,11
// 1191, 1209, 1227, // 1209 12,13,14
// 1316, 1336, 1356, // 1336 15,16,17
// 1455, 1477, 1499, // 1477 18,19,20
// 1609, 1633, 1647, 1657 // 1633 21,22,23,24
// 687, 697, 707, // 697 0,1,2
out[0] = frame[freqIndicies[0]];
if (freqIndicies[0] != freqIndicies[1])
out[0] += frame[freqIndicies[1]];
if (freqIndicies[0] != freqIndicies[2] && freqIndicies[1] != freqIndicies[2])
out[0] += frame[freqIndicies[2]];
// 758, 770, 782, // 770 3,4,5
out[1] = frame[freqIndicies[3]];
if (freqIndicies[3] != freqIndicies[4])
out[1] += frame[freqIndicies[4]];
if (freqIndicies[3] != freqIndicies[5] && freqIndicies[4] != freqIndicies[5])
out[1] += frame[freqIndicies[5]];
// 839, 852, 865, // 852 6,7,8
out[2] = frame[freqIndicies[6]];
if (freqIndicies[6] != freqIndicies[7])
out[2] += frame[freqIndicies[7]];
if (freqIndicies[6] != freqIndicies[8] && freqIndicies[7] != freqIndicies[8])
out[2] += frame[freqIndicies[8]];
// 927, 941, 955, // 941 9,10,11
out[3] = frame[freqIndicies[9]];
if (freqIndicies[9] != freqIndicies[10])
out[3] += frame[freqIndicies[10]];
if (freqIndicies[9] != freqIndicies[11] && freqIndicies[10] != freqIndicies[11])
out[3] += frame[freqIndicies[11]];
// 1191, 1209, 1227, // 1209 12,13,14
out[4] = frame[freqIndicies[12]];
if (freqIndicies[12] != freqIndicies[13])
out[4] += frame[freqIndicies[13]];
if (freqIndicies[12] != freqIndicies[14] && freqIndicies[13] != freqIndicies[14])
out[5] += frame[freqIndicies[14]];
// 1316, 1336, 1356, // 1336 15,16,17
out[5] = frame[freqIndicies[15]];
if (freqIndicies[15] != freqIndicies[16])
out[5] += frame[freqIndicies[16]];
if (freqIndicies[15] != freqIndicies[17] && freqIndicies[16] != freqIndicies[17])
out[5] += frame[freqIndicies[17]];
// 1455, 1477, 1499, // 1477 18,19,20
out[6] = frame[freqIndicies[18]];
if (freqIndicies[18] != freqIndicies[19])
out[6] += frame[freqIndicies[19]];
if (freqIndicies[18] != freqIndicies[20] && freqIndicies[19] != freqIndicies[20])
out[6] += frame[freqIndicies[20]];
out[7] = frame[freqIndicies[21]];
if (frame[freqIndicies[22]] != frame[freqIndicies[21]])
out[7] += frame[freqIndicies[22]];
else
out[7] += frame[freqIndicies[23]];
out[7] += frame[freqIndicies[24]];
return out;
}
/**
* Method returns the DTMF sequence
*
* @return char array with the keys represented in the file
* @throws DTMFDecoderException
* Throws excepion when the file has not been decoded yet.
*/
public String[] getDecoded() throws DTMFDecoderException {
if (!decoded)
throw new DTMFDecoderException("File has not been decoded yet. Please run the method decode() first!");
return seq;
}
/**
* Method to generate a frequency spectrum of the frame using FFT
*
* @param frame
* Frame to be transformed
* @param Fs
* Sampling Frequency
* @return an Array showing the realtive powers of all frequencies
*/
private static double[] transformFrameFFT(double[] frame, int Fs) {
final FastFourierTransformer fft = new FastFourierTransformer(DftNormalization.STANDARD);
final Complex[] spectrum = fft.transform(frame, TransformType.FORWARD);
final double[] powerSpectrum = new double[frame.length / 2 + 1];
for (int ii = 0; ii < powerSpectrum.length; ii++) {
final double abs = spectrum[ii].abs();
powerSpectrum[ii] = abs * abs;
}
return powerSpectrum;
}
/**
* Method to generate a frequency spectrum of the frame using Goertzel
* Algorithm
*
* @param frame
* Frame to be transformed
* @param Fs
* Sampling Frequency
* @return an Array showing the realtive powers of the DTMF frequencies
* @throws DTMFDecoderException
* If no samples have been provided for the goertze class to
* transform
*/
private static double[] transformFrameG(double[] frame, int Fs) throws DTMFDecoderException {
double[] out;
GoertzelOptimised g = new GoertzelOptimised(Fs, frame, DTMF_FREQUENCIES_BIN);
// 1. transform the frames using goertzel algorithm
// 2. get the highest DTMF freq within the tolerance range and use that
// magnitude to represet the corresponsing DTMF free
if (g.compute()) {
out = filterFrameG(g.getMagnitudeSquared());
return out;
} else {
throw new DTMFDecoderException("Decoding failed.");
}
}
/**
* Method to get the highest DTMF freq within the tolerance range and use
* that magnitude to represet the corresponsing DTMF freq
*
* @param frame
* Frame with 274 magnitudes to be processed
* @return an array with 8 magnitudes. Each representing the magnitude of
* each frequency
*/
private static double[] filterFrameG(double[] frame) {
double[] out = new double[8];
out[0] = DecoderUtil.max(Arrays.copyOfRange(frame, 0, 3));
out[1] = DecoderUtil.max(Arrays.copyOfRange(frame, 3, 6));
out[2] = DecoderUtil.max(Arrays.copyOfRange(frame, 6, 9));
out[3] = DecoderUtil.max(Arrays.copyOfRange(frame, 9, 12));
out[4] = DecoderUtil.max(Arrays.copyOfRange(frame, 12, 15));
out[5] = DecoderUtil.max(Arrays.copyOfRange(frame, 15, 18));
out[6] = DecoderUtil.max(Arrays.copyOfRange(frame, 18, 21));
out[7] = DecoderUtil.max(Arrays.copyOfRange(frame, 21, 25));
return out;
}
/**
* Method to detect whether a frame is too noisy for detection
*
* @param dft_data
* Frequency spectrum magnitudes for the DTMF frequencies
* @param power_spectrum
* @return true is noisy or false if it is acceptable
*/
private boolean isNoisy(double[] dft_data, double[] power_spectrum) {
if (power_spectrum == null)
return true;
// sum the powers of all frequencies = sum
// find ratio of the (sum of two highest peaks) : sum
double[] temp1 = Arrays.copyOfRange(dft_data, 0, 4);
double[] temp2 = Arrays.copyOfRange(dft_data, 4, 8);
Arrays.sort(temp1);
Arrays.sort(temp2);
// ratio = (max(lower freqs) + max(higher freqs))/sum(all freqs in
// spectrum)
return ((temp1[temp1.length - 1] + temp2[temp2.length - 1])
/ DecoderUtil.sumArray(power_spectrum)) < FFT_CUT_OFF_POWER_NOISE_RATIO;
}
private boolean isNoisyG(double[] dft_data) {
// sum the powers of all frequencies = sum
// find ratio of the (sum of two highest peaks) : sum
double[] temp1 = Arrays.copyOfRange(dft_data, 0, 4);
double[] temp2 = Arrays.copyOfRange(dft_data, 4, 8);
Arrays.sort(temp1);
Arrays.sort(temp2);
double one = temp1[temp1.length - 1];
double two = temp2[temp2.length - 1];
double sum = DecoderUtil.sumArray(dft_data);
return ((one + two) / sum) < GOERTZEL_CUT_OFF_POWER_NOISE_RATIO;
}
/**
* Method to decode a frame given the frequency spectrum information of the
* frame
*
* @param dft_data
* Frequency spectrum information showing the relative magnitudes
* of the power of each DTMF frequency
* @return DTMF charatcter represented by the frame
* @throws DTMFDecoderException
*/
private static char getRawChar(double[] dft_data) throws DTMFDecoderException {
char out = 0;
int low, hi;
double[] lower = Arrays.copyOfRange(dft_data, 0, 4);
double[] higher = Arrays.copyOfRange(dft_data, 4, 8);
low = DecoderUtil.maxIndex(lower);
hi = DecoderUtil.maxIndex(higher);
if (low == 0) { // low = 697
if (hi == 0) { // High = 1209
out = '1';
} else if (hi == 1) { // high = 1336
out = '2';
} else if (hi == 2) { // high = 1477
out = '3';
} else if (hi == 3) { // high = 1633
out = 'A';
} else
throw new DTMFDecoderException("Something went terribly wrong!");
} else if (low == 1) { // low = 770
if (hi == 0) { // high = 1209
out = '4';
} else if (hi == 1) { // high = 1336
out = '5';
} else if (hi == 2) { // high = 1477
out = '6';
} else if (hi == 3) { // high = 1633
out = 'B';
} else
throw new DTMFDecoderException("Something went terribly wrong!");
} else if (low == 2) { // low = 852
if (hi == 0) { // high = 1209
out = '7';
} else if (hi == 1) { // high = 1336
out = '8';
} else if (hi == 2) { // high = 1477
out = '9';
} else if (hi == 3) { // high = 1633
out = 'C';
} else
throw new DTMFDecoderException("Something went terribly wrong!");
} else if (low == 3) { // low = 941
if (hi == 0) { // high = 1209
out = '*';
} else if (hi == 1) { // high = 1336
out = '0';
} else if (hi == 2) { // high = 1477
out = '#';
} else if (hi == 3) { // high = 1633
out = 'D';
} else
throw new DTMFDecoderException("Something went terribly wrong!");
} else
throw new DTMFDecoderException("Something went terribly wrong!");
return out;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws AudioFileException
* @throws WavFileException
*/
private void decodeMono40() throws IOException, AudioFileException {
char prev = '_';
char prev2 = '_';
String seq2 = "";
String seq22 = "";
int count = 0;
do {
char curr;
try {
curr = decodeNextFrameMono();
} catch (DTMFDecoderException e) {
break;
}
if (debug)
System.out.print(curr);
// System.out.print(curr);
if (curr != '_') {
if (curr == prev) { // eliminate false positives
if (curr != prev2) {
if (debug) {
seq22 = seq22.substring(0, seq22.length() - 1);
seq22 += curr + ".";
count = 0;
seq2 += curr;
} else {
seq22 += curr + ".";
seq2 += curr;
}
}
}
}
if (count % 50 == 0) {
seq22 += '_';
}
count++;
prev2 = prev;
prev = curr;
} while (true);
seq[0] = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws AudioFileException
* @throws WavFileException
*/
private void decodeMono60() throws IOException, AudioFileException {
char prev = '_';
char prev2 = '_';
char prev3 = '_';
String seq2 = "";
String seq22 = "";
int count = 0;
do {
char curr;
try {
curr = decodeNextFrameMono();
} catch (DTMFDecoderException e) {
break;
}
if (debug)
System.out.print(curr);
// System.out.print(curr);
if (curr != '_') {
if (curr == prev && curr == prev2) { // eliminate false
// positives
if (curr != prev3) {
if (debug) {
seq22 = seq22.substring(0, seq22.length() - 1);
seq22 += curr + ".";
count = 0;
seq2 += curr;
} else {
seq22 += curr + ".";
seq2 += curr;
}
}
}
}
if (count % 30 == 0) {
seq22 += '_';
}
count++;
prev3 = prev2;
prev2 = prev;
prev = curr;
} while (true);
seq[0] = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws AudioFileException
* @throws WavFileException
*/
private void decodeMono80() throws IOException, AudioFileException {
char prev = '_';
char prev2 = '_';
char prev3 = '_';
char prev4 = '_';
String seq2 = "";
String seq22 = "";
int count = 0;
do {
char curr;
try {
curr = decodeNextFrameMono();
} catch (DTMFDecoderException e) {
break;
}
if (debug)
System.out.print(curr);
// System.out.print(curr);
if (curr != '_') {
if (curr == prev && curr == prev2 && curr == prev3) { // eliminate
// false
// positives
if (curr != prev4) {
if (debug) {
seq22 = seq22.substring(0, seq22.length() - 1);
seq22 += curr + ".";
count = 0;
seq2 += curr;
} else {
seq22 += curr + ".";
seq2 += curr;
}
}
}
}
if (count % 100 == 0) {
seq22 += '_';
}
count++;
prev4 = prev3;
prev3 = prev2;
prev2 = prev;
prev = curr;
} while (true);
seq[0] = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws AudioFileException
* @throws WavFileException
*/
private void decodeMono100() throws IOException, AudioFileException {
char prev = '_';
char prev2 = '_';
char prev3 = '_';
char prev4 = '_';
char prev5 = '_';
String seq2 = "";
String seq22 = "";
int count = 0;
do {
char curr;
try {
curr = decodeNextFrameMono();
} catch (DTMFDecoderException e) {
break;
}
if (debug)
System.out.print(curr);
// System.out.print(curr);
if (curr != '_') {
if (curr == prev && curr == prev2 && curr == prev3 && curr == prev4) { // eliminate
// false
// positives
if (curr != prev5) {
if (debug) {
seq22 = seq22.substring(0, seq22.length() - 1);
seq22 += curr + ".";
count = 0;
seq2 += curr;
} else {
seq22 += curr + ".";
seq2 += curr;
}
}
}
}
if (count % 100 == 0) {
seq22 += '_';
}
count++;
prev5 = prev4;
prev4 = prev3;
prev3 = prev2;
prev2 = prev;
prev = curr;
} while (true);
seq[0] = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws WavFileException
*/
private void decodeStereo40() throws IOException, AudioFileException {
char curr[];
char[] prev = { '_', '_' };
char[] prev2 = { '_', '_' };
String[] seq2 = { "", "" };
do {
try {
curr = decodeNextFrameStereo();
} catch (DTMFDecoderException e) {
break;
}
// decode channel 1
if (curr[0] != '_') {
if (curr[0] == prev[0]) { // eliminate false positives
if (curr[0] != prev2[0]) {
seq2[0] += curr[0];
}
}
}
prev2[0] = prev[0];
prev[0] = curr[0];
// decode channel 2
if (curr[1] != '_') {
if (curr[1] == prev[1]) { // eliminate false positives
if (curr[1] != prev2[1]) {
seq2[1] += curr[1];
}
}
}
prev2[1] = prev[1];
prev[1] = curr[1];
} while (true);
seq = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws WavFileException
*/
private void decodeStereo60() throws IOException, AudioFileException {
char curr[];
char[] prev = { '_', '_' };
char[] prev2 = { '_', '_' };
char[] prev3 = { '_', '_' };
String[] seq2 = { "", "" };
do {
try {
curr = decodeNextFrameStereo();
} catch (DTMFDecoderException e) {
break;
}
// decode channel 1
if (curr[0] != '_') {
if (curr[0] == prev[0] && curr[0] == prev2[0]) { // eliminate
// false
// positives
if (curr[0] != prev3[0]) {
seq2[0] += curr[0];
}
}
}
prev3[0] = prev2[0];
prev2[0] = prev[0];
prev[0] = curr[0];
// decode channel 2
if (curr[1] != '_') {
if (curr[1] == prev[1] && curr[1] == prev2[1]) { // eliminate
// false
// positives
if (curr[1] != prev3[1]) {
seq2[1] += curr[1];
}
}
}
prev3[1] = prev2[1];
prev2[1] = prev[1];
prev[1] = curr[1];
} while (true);
seq = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws WavFileException
*/
private void decodeStereo80() throws IOException, AudioFileException {
char curr[];
char[] prev = { '_', '_' };
char[] prev2 = { '_', '_' };
char[] prev3 = { '_', '_' };
char[] prev4 = { '_', '_' };
String[] seq2 = { "", "" };
do {
try {
curr = decodeNextFrameStereo();
} catch (DTMFDecoderException e) {
break;
}
// decode channel 1
if (curr[0] != '_') {
if (curr[0] == prev[0] && curr[0] == prev2[0] && curr[0] == prev3[0]) { // eliminate
// false
// positives
if (curr[0] != prev4[0]) {
seq2[0] += curr[0];
}
}
}
prev4[0] = prev3[0];
prev3[0] = prev2[0];
prev2[0] = prev[0];
prev[0] = curr[0];
// decode channel 2
if (curr[1] != '_') {
if (curr[1] == prev[1] && curr[1] == prev2[1] && curr[1] == prev3[1]) { // eliminate
// false
// positives
if (curr[1] != prev4[1]) {
seq2[1] += curr[1];
}
}
}
prev4[1] = prev3[1];
prev3[1] = prev2[1];
prev2[1] = prev[1];
prev[1] = curr[1];
} while (true);
seq = seq2;
}
/**
* Method to decode the wav file.
*
* @return String representation of the sequence of DTMF tones represented
* in the wav file
* @throws IOException
* @throws WavFileException
*/
private void decodeStereo100() throws IOException, AudioFileException {
char curr[];
char[] prev = { '_', '_' };
char[] prev2 = { '_', '_' };
char[] prev3 = { '_', '_' };
char[] prev4 = { '_', '_' };
char[] prev5 = { '_', '_' };
String[] seq2 = { "", "" };
do {
try {
curr = decodeNextFrameStereo();
} catch (DTMFDecoderException e) {
break;
}
// decode channel 1
if (curr[0] != '_') {
if (curr[0] == prev[0] && curr[0] == prev2[0] && curr[0] == prev3[0] && curr[0] == prev4[0]) { // eliminate
// false
// positives
if (curr[0] != prev5[0]) {
seq2[0] += curr[0];
}
}
}
prev5[0] = prev4[0];
prev4[0] = prev3[0];
prev3[0] = prev2[0];
prev2[0] = prev[0];
prev[0] = curr[0];
// decode channel 2
if (curr[1] != '_') {
if (curr[1] == prev[1] && curr[1] == prev2[1] && curr[1] == prev3[1] && curr[1] == prev4[1]) { // eliminate
// false
// positives
if (curr[1] != prev5[1]) {
seq2[1] += curr[1];
}
}
}
prev5[1] = prev4[1];
prev4[1] = prev3[1];
prev3[1] = prev2[1];
prev2[1] = prev[1];
prev[1] = curr[1];
} while (true);
seq = seq2;
}
/**
* Method to decode the next frame in a buffer of a mono channeled wav file
*
* @return the decoded DTMF character
* @throws AudioFileException
* @throws IOException
* @throws WavFileException
* @throws DTMFDecoderException
*/
private char decodeNextFrameMono() throws AudioFileException, DTMFDecoderException, IOException {
int bufferSize = (int) Math.ceil(frameSize / 3.0);
double[] buffer = new double[bufferSize];
double[] tempBuffer11 = new double[bufferSize];
double[] tempBuffer21 = new double[bufferSize];
int framesRead = audio.read(buffer);
if (framesRead < bufferSize) {
audio.close();
throw new DTMFDecoderException("Out of frames");
}
double[] frame;
if (goertzel) {
frame = DecoderUtil.concatenateAll(tempBuffer21, tempBuffer11, buffer);
tempBuffer21 = tempBuffer11;
tempBuffer11 = buffer;
} else {
// slice off the extra bit to make the framesize a power of 2
int slice = buffer.length + tempBuffer11.length + tempBuffer21.length - frameSize;
double[] sliced = Arrays.copyOfRange(buffer, 0, buffer.length - slice);
frame = DecoderUtil.concatenateAll(tempBuffer21, tempBuffer11, sliced);
tempBuffer21 = tempBuffer11;
tempBuffer11 = buffer;
}
char out;
// check if the power of the signal is high enough to be accepted.
if (DecoderUtil.signalPower(frame) < CUT_OFF_POWER)
return '_';
if (goertzel) {
// transform frame and return frequency spectrum information
double[] dft_data = DTMFUtil.transformFrameG(frame, (int) audio.getSampleRate());
// check if the frame has too much noise
if (isNoisyG(dft_data))
return '_';
out = DTMFUtil.getRawChar(dft_data);
return out;
} else {
// transform frame and return frequency spectrum information
double[] power_spectrum = DTMFUtil.transformFrameFFT(frame, (int) audio.getSampleRate());
// filter out the 8 DTMF frequencies from the power spectrum
double[] dft_data = filterFrame(power_spectrum);
// check if the frame has too much noise
if (isNoisy(dft_data, power_spectrum))
return '_';
out = DTMFUtil.getRawChar(dft_data);
return out;
}
}
/**
* Method to decode the next frame in a buffer of a stereo wav file
*
* @return the decoded DTMF character
* @throws IOException
* @throws WavFileException
* @throws DTMFDecoderException
*/
private char[] decodeNextFrameStereo() throws IOException, AudioFileException, DTMFDecoderException {
int bufferSize = (int) Math.ceil(frameSize / 3.0);
double[][] buffer = new double[2][bufferSize];
double[] tempBuffer11 = new double[bufferSize];
double[] tempBuffer21 = new double[bufferSize];
double[] tempBuffer12 = new double[bufferSize];
double[] tempBuffer22 = new double[bufferSize];
int framesRead = audio.read(buffer);
if (framesRead < bufferSize) {
audio.close();
throw new DTMFDecoderException("Out of frames");
}
double[] frame1, frame2;
if (goertzel) {
frame1 = DecoderUtil.concatenateAll(tempBuffer21, tempBuffer11, buffer[0]);
frame2 = DecoderUtil.concatenateAll(tempBuffer22, tempBuffer12, buffer[1]);
tempBuffer21 = tempBuffer11;
tempBuffer11 = buffer[0];
tempBuffer22 = tempBuffer12;
tempBuffer12 = buffer[1];
} else {
int slice = buffer.length + tempBuffer11.length + tempBuffer21.length - frameSize;
double[] sliced1 = Arrays.copyOfRange(buffer[0], 0, buffer.length - slice);
double[] sliced2 = Arrays.copyOfRange(buffer[1], 0, buffer.length - slice);
frame1 = DecoderUtil.concatenateAll(tempBuffer21, tempBuffer11, sliced1);
frame2 = DecoderUtil.concatenateAll(tempBuffer22, tempBuffer12, sliced2);
tempBuffer21 = tempBuffer11;
tempBuffer11 = buffer[0];
tempBuffer22 = tempBuffer12;
tempBuffer12 = buffer[1];
}
char[] outArr = { 'T', 'T' };
// check if the power of the signal is high enough to be accepted.
if (DecoderUtil.signalPower(frame1) < CUT_OFF_POWER) {
outArr[0] = '_';
}
if (DecoderUtil.signalPower(frame2) < CUT_OFF_POWER) {
outArr[1] = '_';
}
if (outArr[0] == '_' && outArr[1] == '_') {
return outArr;
}
if (goertzel) {
// transform frame
double[] dft_data1 = transformFrameG(frame1, (int) audio.getSampleRate());
double[] dft_data2 = transformFrameG(frame2, (int) audio.getSampleRate());
// check if the frame has too much noise
if (isNoisyG(dft_data1)) {
outArr[0] = '_';
}
if (isNoisyG(dft_data2)) {
outArr[1] = '_';
}
if (outArr[0] == '_' && outArr[1] == '_') {
return outArr;
}
try {
if (outArr[0] != '_') {
outArr[0] = getRawChar(dft_data1);
}
if (outArr[1] != '_') {
outArr[1] = getRawChar(dft_data2);
}
} catch (DTMFDecoderException e) {
e.printStackTrace();
throw new DTMFDecoderException("Something went wrong.");
}
return outArr;
} else {
// transform frames
double[] power_spectrum1, power_spectrum2;
// transform channel 1
if (outArr[0] != '_') {
power_spectrum1 = DTMFUtil.transformFrameFFT(frame1, (int) audio.getSampleRate());
} else {
power_spectrum1 = null;
}
// transform channel 2
if (outArr[1] != '_') {
power_spectrum2 = DTMFUtil.transformFrameFFT(frame2, (int) audio.getSampleRate());
} else {
power_spectrum2 = null;
}
// filter frame 1
double[] dft_data1, dft_data2;
if (power_spectrum1 != null) {
dft_data1 = filterFrame(power_spectrum1);
} else {
dft_data1 = null;
}
// filter frame 2
if (power_spectrum2 != null) {
dft_data2 = filterFrame(power_spectrum2);
} else {
dft_data2 = null;
}
// check if the frame 1 has too much noise
if (isNoisy(dft_data1, power_spectrum1)) {
outArr[0] = '_';
}
if (isNoisy(dft_data2, power_spectrum2)) {
outArr[1] = '_';
}
if (outArr[0] == '_' && outArr[1] == '_') {
return outArr;
}
try {
if (outArr[0] != '_') {
outArr[0] = DTMFUtil.getRawChar(dft_data1);
}
if (outArr[1] != '_') {
outArr[1] = DTMFUtil.getRawChar(dft_data2);
}
} catch (DTMFDecoderException e) {
e.printStackTrace();
throw new DTMFDecoderException("Something went wrong.");
}
return outArr;
}
}
/**
* Method to decode the wav file and return the sequence of DTMF tones
* represented.
*
* @return True if decoding process was successful
* @throws IOException
* @throws WavFileException
* @throws DTMFDecoderException
*/
public boolean decode() throws IOException, AudioFileException, DTMFDecoderException {
if (!decoder)
throw new DTMFDecoderException(
"The object was not instantiated in decoding mode. Please use the correct constructor.");
if (decoded) {
return true;
}
if (audio.getNumChannels() == 1) {
if (decode60)
decodeMono60();
else if (decode80)
decodeMono80();
else if (decode100)
decodeMono100();
else
decodeMono40();
decoded = true;
} else if (audio.getNumChannels() == 2) {
if (decode60)
decodeStereo60();
else if (decode80)
decodeStereo80();
else if (decode100)
decodeStereo100();
else
decodeStereo40();
decoded = true;
} else
throw new DTMFDecoderException("Can only decode mono and stereo files.");
return true;
}
/**
* Method to set the minimum duration of the DTMF tones to be detected
*
* @param duration
* minimum duration of a tone. 0 or negative to use the default
* ITU-T recommended value (40ms)
* @throws DTMFDecoderException
* Throws an exception if the duration is less than 40ms
*/
public static void setMinToneDuration(int duration) throws DTMFDecoderException {
if (duration <= 0) // use default duration of 40ms
return;
else if (duration < 40)
throw new DTMFDecoderException(
"Minimum tone duration must be greater than 40ms or, use 0 or a negative number to use the default ITU-T value.");
else if (duration < 80)
decode60 = true;
else if (duration < 100)
decode80 = true;
else if (duration > 100)
decode100 = true;
else if (duration < Integer.MAX_VALUE)
decode100 = true;
else
throw new DTMFDecoderException("the given minimum tone duration is too long.");
}
/**
* Method to check if the given audio file has been decoded.
*/
public boolean isDecoded() {
return decoded;
}
/**
* Method to get the number of channels in the audio files being decoded
*
* @return
*/
public int getChannelCount() {
return audio.getNumChannels();
}
/**
* Method to generate the DTMF tone.
*
* @return True if generation was successful
* @throws DTMFDecoderException
*/
public boolean generate() throws DTMFDecoderException {
if (!generate)
throw new DTMFDecoderException(
"The object was not instantiated in the generation mode. Plese use the correct constructor.");
ArrayList<Double> outSamples = new ArrayList<Double>();
// calculate length (number of samples) of the tones and pauses
int toneLen = (int) Math.floor((outToneDurr * outFs) / 1000.0);
int pauseLen = (int) Math.floor((outPauseDurr * outFs) / 1000.0);
// Add a pause at beginning of the file
addPause(outSamples, pauseLen);
// add the tones
for (int i = 0; i < outChars.length; i++) {
// add tone samples
addTone(outSamples, outChars[i], toneLen);
// add pause samples
addPause(outSamples, pauseLen);
}
// Add a pause at the end of the file
addPause(outSamples, pauseLen);
generatedSeq = new double[outSamples.size()];
for (int i = 0; i < generatedSeq.length; i++)
generatedSeq[i] = outSamples.get(i);
generated = true;
return true;
}
/**
* Method to generate samples representing a dtmf tone
*
* @param samples
* array of samples to add the generated samples to.
* @param c
* DTMF character to generate.
* @param toneLen
* Number of samples to generate.
* @throws DTMFDecoderException
* If the given character is not a dtmf character.
*/
private void addTone(ArrayList<Double> samples, char c, int toneLen) throws DTMFDecoderException {
double[] f = getFreqs(c);
for (double s = 0; s < toneLen; s++) {
double lo = Math.sin(2.0 * Math.PI * f[0] * s / outFs);
double hi = Math.sin(2.0 * Math.PI * f[1] * s / outFs);
samples.add((hi + lo) / 2.0);
// samples.add(hi);
}
}
/**
* Method get the DTMF lower and upper frequencies.
*
* @param c
* DTMF character
* @return DTMF Frequencies to use to generate the tone.
* @throws DTMFDecoderException
* If the given character is not a DTMF character.
*/
private double[] getFreqs(char c) throws DTMFDecoderException {
double[] out = new double[2];
if (c == '0') {
out[0] = 941;
out[1] = 1336;
} else if (c == '1') {
out[0] = 697;
out[1] = 1209;
} else if (c == '2') {
out[0] = 697;
out[1] = 1336;
} else if (c == '3') {
out[0] = 697;
out[1] = 1477;
} else if (c == '4') {
out[0] = 770;
out[1] = 1209;
} else if (c == '5') {
out[0] = 770;
out[1] = 1336;
} else if (c == '6') {
out[0] = 770;
out[1] = 1477;
} else if (c == '7') {
out[0] = 852;
out[1] = 1209;
} else if (c == '8') {
out[0] = 852;
out[1] = 1336;
} else if (c == '9') {
out[0] = 852;
out[1] = 1477;
} else if (c == 'A' || c == 'a') {
out[0] = 697;
out[1] = 1633;
} else if (c == 'B' || c == 'b') {
out[0] = 770;
out[1] = 1633;
} else if (c == 'C' || c == 'c') {
out[0] = 852;
out[1] = 1633;
} else if (c == 'D' || c == 'd') {
out[0] = 941;
out[1] = 1633;
} else
throw new DTMFDecoderException("\"" + c + "\" is not a DTMF Character.");
return out;
}
/**
* Method to add samples that represent a pause to the output
*
* @param samples
* Array of samples to add to.
* @param pauseLen
* Number of samples to add.
*/
private void addPause(ArrayList<Double> samples, int pauseLen) {
for (int s = 0; s < pauseLen; s++)
samples.add(0.0);
}
/**
* Write the generated sequenec to a wav file.
*
* @throws WavFileException
* @throws IOException
*/
public void export() throws IOException, WavFileException {
FileUtil.writeWavFile(outFile, generatedSeq, outFs);
}
/**
* Get the samples array of the DTMF sequence of tones.
*
* @return array with the samples of the dtmf sequence that has been
* generated.
* @throws DTMFDecoderException
* If the samples have no been generated yet.
*/
public double[] getGeneratedSequence() throws DTMFDecoderException {
if (generated)
return generatedSeq;
else
throw new DTMFDecoderException("Samples have not been generated yet. Please run generate() first.");
}
}
