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protected void predict(float[] vec, int N, int direction) {
int half = N >> 1;
for (int i = 0; i < half; i++) {
float predictVal = vec[i];
int j = i + half;
if (direction == forward) {
vec[j] = vec[j] - predictVal;
} else if (direction == inverse) {
vec[j] = vec[j] + predictVal;
} else {
System.out.println("HaarWavelet::predict: bad direction value");
}
}
} |
HaarWavelet predict step
| HaarWavelet::predict | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/wavelet/lift/HaarWavelet.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/wavelet/lift/HaarWavelet.java | Apache-2.0 |
public void forwardTransOne(float[] vec) {
final int N = vec.length;
split(vec, N);
predict(vec, N, forward);
update(vec, N, forward);
} // forwardTrans |
Transform forward
@param vec the vector to update.
| HaarWavelet::forwardTransOne | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/wavelet/lift/HaarWavelet.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/wavelet/lift/HaarWavelet.java | Apache-2.0 |
protected void update(float[] vec, int N, int direction) {
int half = N >> 1;
for (int i = 0; i < half; i++) {
int j = i + half;
float updateVal = vec[j] / 2.0f;
if (direction == forward) {
vec[i] = vec[i] + updateVal;
} else if (direction == inverse) {
vec[i] = vec[i] - updateVal;
} else {
System.out.println("update: bad direction value");
}
}
} |
<p>
Update step of the HaarWavelet wavelet transform.
</p>
<p>
The wavelet transform calculates a set of detail or difference
coefficients in the predict step. These are stored in the upper half of
the array. The update step calculates an average from the even-odd
element pairs. The averages will replace the even elements in the lower
half of the array.
</p>
<p>
The HaarWavelet wavelet calculation used in the Lifting Scheme is
</p>
<pre>
d j+1, i = odd j+1, i = odd j, i - even j, i
a j+1, i = even j, i = (even j, i + odd j, i )/2
</pre>
<p>
Note that the Lifting Scheme uses an in-place algorithm. The odd elements
have been replaced by the detail coefficients in the predict step. With a
little algebra we can substitute the coefficient calculation into the
average calculation, which gives us
</p>
<pre>
a j+1, i = even j, i = even j, i + (odd j, i /2)
</pre>
| HaarWavelet::update | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/wavelet/lift/HaarWavelet.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/wavelet/lift/HaarWavelet.java | Apache-2.0 |
public void inverseTrans(float[] vec) {
final int N = vec.length;
for (int n = 2; n <= N; n = n << 1) {
normalize(vec, n, inverse);
update(vec, n, inverse);
predict(vec, n, inverse);
updateOne(vec, n, inverse);
merge(vec, n);
}
} // inverseTrans |
<p>
Default two step Lifting Scheme inverse wavelet transform
</p>
<p>
inverseTrans is passed the result of an ordered wavelet transform,
consisting of an average and a set of wavelet coefficients. The inverse
transform is calculated in-place and the result is returned in the
argument array.
</p>
| Daubechies4Wavelet::inverseTrans | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/wavelet/lift/Daubechies4Wavelet.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/wavelet/lift/Daubechies4Wavelet.java | Apache-2.0 |
private PitchConverter() {
} |
Hide the default constructor.
| PitchConverter::PitchConverter | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static int hertzToMidiKey(final Double hertzValue) {
final int midiKey = (int) Math.round(hertzToMidiCent(hertzValue));
if (midiKey < 0 || midiKey > 127) {
// TODO
// LOG.warning("MIDI is only defined between [" + midiKeyToHertz(0)
// + ","
// + midiKeyToHertz(127) + "] " + hertzValue +
// "does not map to a MIDI key.");
}
return midiKey;
} |
A MIDI key is an integer between 0 and 127, inclusive. Within a certain
range every pitch is mapped to a MIDI key. If a value outside the range
is given an IllegalArugmentException is thrown.
@param hertzValue
The pitch in Hertz.
@return An integer representing the closest midi key.
@exception IllegalArgumentException
if the hertzValue does not fall within the range of valid
MIDI key frequencies.
| PitchConverter::hertzToMidiKey | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double midiKeyToHertz(final int midiKey) {
if (midiKey < 0 || midiKey > 127) {
throw new IllegalArgumentException("MIDI keys are values from 0 to 127, inclusive " + midiKey
+ " is invalid.");
}
return midiCentToHertz(midiKey);
} |
Calculates the frequency (Hz) for a MIDI key.
@param midiKey
The MIDI key. A MIDI key is an integer between 0 and 127,
inclusive.
@return A frequency in Hz corresponding to the MIDI key.
@exception IllegalArgumentException
If midiKey is not in the valid range between 0 and 127,
inclusive.
| PitchConverter::midiKeyToHertz | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double hertzToRelativeCent(final double hertzValue) {
double absoluteCentValue = hertzToAbsoluteCent(hertzValue);
// make absoluteCentValue positive. E.g. -2410 => 1210
if (absoluteCentValue < 0) {
absoluteCentValue = Math.abs(1200 + absoluteCentValue);
}
// so it can be folded to one octave. E.g. 1210 => 10
return absoluteCentValue % 1200.0;
} |
Converts a Hertz value to relative cents. E.g. 440Hz is converted to 900
if the reference is a C.
@param hertzValue
A value in hertz.
@return A value in relative cents.
| PitchConverter::hertzToRelativeCent | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double hertzToAbsoluteCent(final double hertzValue) {
double pitchInAbsCent = 0.0;
if (hertzValue > 0) {
pitchInAbsCent = 1200 * Math.log(hertzValue / REF_FREQ) / LOG_TWO;
} else {
throw new IllegalArgumentException("Pitch in Hz schould be greater than zero, is " + hertzValue);
}
return pitchInAbsCent;
} |
The reference frequency is configured. The default reference frequency is
16.35Hz. This is C0 on a piano keyboard with A4 tuned to 440 Hz. This
means that 0 cents is C0; 1200 is C1; 2400 is C2; ... also -1200 cents is
C-1
@param hertzValue
The pitch in Hertz.
@return The value in absolute cents using the configured reference
frequency
| PitchConverter::hertzToAbsoluteCent | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double absoluteCentToHertz(final double absoluteCent) {
return REF_FREQ * Math.pow(2, absoluteCent / 1200.0);
} |
Returns the frequency (Hz) of an absolute cent value. This calculation
uses a configured reference frequency.
@param absoluteCent
The pitch in absolute cent.
@return A pitch in Hz.
| PitchConverter::absoluteCentToHertz | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double hertzToMidiCent(final double hertzValue) {
double pitchInMidiCent = 0.0;
if (hertzValue != 0) {
pitchInMidiCent = 12 * Math.log(hertzValue / 440) / LOG_TWO + 69;
}
return pitchInMidiCent;
} |
Converts a frequency in Hz to a MIDI CENT value using
<code>(12 * log2 (f / 440)) + 69</code> <br>
E.g.<br>
<code>69.168 MIDI CENTS = MIDI NOTE 69 + 16,8 cents</code><br>
<code>69.168 MIDI CENTS = 440Hz + x Hz</code>
@param hertzValue
The pitch in Hertz.
@return The pitch in MIDI cent.
| PitchConverter::hertzToMidiCent | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double midiCentToHertz(final double midiCent) {
return 440 * Math.pow(2, (midiCent - 69) / 12d);
} |
Converts a MIDI CENT frequency to a frequency in Hz.
@param midiCent
The pitch in MIDI CENT.
@return The pitch in Hertz.
| PitchConverter::midiCentToHertz | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double centToRatio(final double cent) {
final double ratio;
ratio = Math.pow(10, Math.log10(2) * cent / 1200.0);
return ratio;
} |
Converts cent values to ratios. See
"Ratios Make Cents: Conversions from ratios to cents and back again" in
the book "Tuning Timbre Spectrum Scale" William A. Sethares.
@param cent
A cent value
@return A ratio containing the same information.
| PitchConverter::centToRatio | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public static double ratioToCent(final double ratio) {
final double cent;
cent = 1200 / Math.log10(2) * Math.log10(ratio);
return cent;
} |
Converts a ratio to cents.
"Ratios Make Cents: Conversions from ratios to cents and back again" in
the book "Tuning Timbre Spectrum Scale" William A. Sethares
@param ratio
A cent value
@return A ratio containing the same information.
| PitchConverter::ratioToCent | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PitchConverter.java | Apache-2.0 |
public Complex(double u,double v) {
x=u;
y=v;
} |
Constructs the complex number z = u + i*v
@param u Real part
@param v Imaginary part
| Complex::Complex | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public double real() {
return x;
} |
Real part of this Complex number
(the x-coordinate in rectangular coordinates).
@return Re[z] where z is this Complex number.
| Complex::real | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public double imag() {
return y;
} |
Imaginary part of this Complex number
(the y-coordinate in rectangular coordinates).
@return Im[z] where z is this Complex number.
| Complex::imag | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public double mod() {
if (x!=0 || y!=0) {
return Math.sqrt(x*x+y*y);
} else {
return 0d;
}
} |
Modulus of this Complex number
(the distance from the origin in polar coordinates).
@return |z| where z is this Complex number.
| Complex::mod | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public double arg() {
return Math.atan2(y,x);
} |
Argument of this Complex number
(the angle in radians with the x-axis in polar coordinates).
@return arg(z) where z is this Complex number.
| Complex::arg | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex conj() {
return new Complex(x,-y);
} |
Complex conjugate of this Complex number
(the conjugate of x+i*y is x-i*y).
@return z-bar where z is this Complex number.
| Complex::conj | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex plus(Complex w) {
return new Complex(x+w.real(),y+w.imag());
} |
Addition of Complex numbers (doesn't change this Complex number).
<br>(x+i*y) + (s+i*t) = (x+s)+i*(y+t).
@param w is the number to add.
@return z+w where z is this Complex number.
| Complex::plus | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex minus(Complex w) {
return new Complex(x-w.real(),y-w.imag());
} |
Subtraction of Complex numbers (doesn't change this Complex number).
<br>(x+i*y) - (s+i*t) = (x-s)+i*(y-t).
@param w is the number to subtract.
@return z-w where z is this Complex number.
| Complex::minus | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex times(Complex w) {
return new Complex(x*w.real()-y*w.imag(),x*w.imag()+y*w.real());
} |
Complex multiplication (doesn't change this Complex number).
@param w is the number to multiply by.
@return z*w where z is this Complex number.
| Complex::times | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex div(Complex w) {
double den=Math.pow(w.mod(),2);
return new Complex((x*w.real()+y*w.imag())/den,(y*w.real()-x*w.imag())/den);
} |
Division of Complex numbers (doesn't change this Complex number).
<br>(x+i*y)/(s+i*t) = ((x*s+y*t) + i*(y*s-y*t)) / (s^2+t^2)
@param w is the number to divide by
@return new Complex number z/w where z is this Complex number
| Complex::div | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex exp() {
return new Complex(Math.exp(x)*Math.cos(y),Math.exp(x)*Math.sin(y));
} |
Complex exponential (doesn't change this Complex number).
@return exp(z) where z is this Complex number.
| Complex::exp | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex log() {
return new Complex(Math.log(this.mod()),this.arg());
} |
Principal branch of the Complex logarithm of this Complex number.
(doesn't change this Complex number).
The principal branch is the branch with -pi < arg <= pi.
@return log(z) where z is this Complex number.
| Complex::log | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex sqrt() {
double r=Math.sqrt(this.mod());
double theta=this.arg()/2;
return new Complex(r*Math.cos(theta),r*Math.sin(theta));
} |
Complex square root (doesn't change this complex number).
Computes the principal branch of the square root, which
is the value with 0 <= arg < pi.
@return sqrt(z) where z is this Complex number.
| Complex::sqrt | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex sin() {
return new Complex(cosh(y)*Math.sin(x),sinh(y)*Math.cos(x));
} |
Sine of this Complex number (doesn't change this Complex number).
<br>sin(z) = (exp(i*z)-exp(-i*z))/(2*i).
@return sin(z) where z is this Complex number.
| Complex::sin | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex cos() {
return new Complex(cosh(y)*Math.cos(x),-sinh(y)*Math.sin(x));
} |
Cosine of this Complex number (doesn't change this Complex number).
<br>cos(z) = (exp(i*z)+exp(-i*z))/ 2.
@return cos(z) where z is this Complex number.
| Complex::cos | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex sinh() {
return new Complex(sinh(x)*Math.cos(y),cosh(x)*Math.sin(y));
} |
Hyperbolic sine of this Complex number
(doesn't change this Complex number).
<br>sinh(z) = (exp(z)-exp(-z))/2.
@return sinh(z) where z is this Complex number.
| Complex::sinh | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex cosh() {
return new Complex(cosh(x)*Math.cos(y),sinh(x)*Math.sin(y));
} |
Hyperbolic cosine of this Complex number
(doesn't change this Complex number).
<br>cosh(z) = (exp(z) + exp(-z)) / 2.
@return cosh(z) where z is this Complex number.
| Complex::cosh | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex tan() {
return (this.sin()).div(this.cos());
} |
Tangent of this Complex number (doesn't change this Complex number).
<br>tan(z) = sin(z)/cos(z).
@return tan(z) where z is this Complex number.
| Complex::tan | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public Complex chs() {
return new Complex(-x,-y);
} |
Negative of this complex number (chs stands for change sign).
This produces a new Complex number and doesn't change
this Complex number.
<br>-(x+i*y) = -x-i*y.
@return -z where z is this Complex number.
| Complex::chs | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public String toString() {
if (x!=0 && y>0) {
return x+" + "+y+"i";
}
if (x!=0 && y<0) {
return x+" - "+(-y)+"i";
}
if (y==0) {
return String.valueOf(x);
}
if (x==0) {
return y+"i";
}
// shouldn't get here (unless Inf or NaN)
return x+" + i*"+y;
} |
String representation of this Complex number.
@return x+i*y, x-i*y, x, or i*y as appropriate.
| Complex::toString | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/Complex.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/Complex.java | Apache-2.0 |
public PeakPicker(double threshold) {
/* Low-pass filter cutoff [0.34, 1] */
biquad = new BiQuadFilter(0.1600,0.3200,0.1600,-0.5949,0.2348);
this.threshold = threshold;
win_post = 5;
win_pre = 1;
onset_keep = new float[win_post + win_pre +1];
onset_proc = new float[win_post + win_pre +1];
scratch = new float[win_post + win_pre +1];
onset_peek = new float[3];
} |
Initializes a new moving mean adaptive threshold peak picker.
@param threshold
The threshold defines when a peak is selected. It should be
between zero and one, 0.3 is a reasonable value. If too many
peaks are detected go to 0.5 - 0.8.
| PeakPicker::PeakPicker | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | Apache-2.0 |
public void setThreshold(double threshold) {
this.threshold = threshold;
} |
Sets a new threshold.
@param threshold
The threshold defines when a peak is selected. It should be
between zero and one, 0.3 is a reasonable value. If too many
peaks are detected go to 0.5 - 0.8.
| PeakPicker::setThreshold | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | Apache-2.0 |
public boolean pickPeak(float onset) {
float mean = 0.f;
float median = 0.f;
int length = win_post + win_pre + 1;
/* store onset in onset_keep */
/* shift all elements but last, then write last */
/* for (i=0;i<channels;i++) { */
for(int j=0;j<length-1;j++) {
onset_keep[j] = onset_keep[j+1];
onset_proc[j] = onset_keep[j];
}
onset_keep[length-1] = onset;
onset_proc[length-1] = onset;
/* filter onset_proc */
/** \bug filtfilt calculated post+pre times, should be only once !? */
biquad.doFiltering(onset_proc,scratch);
/* calculate mean and median for onset_proc */
/* copy to scratch */
float sum = 0.0f;
for (int j = 0; j < length; j++){
scratch[j] = onset_proc[j];
sum += scratch[j];
}
Arrays.sort(scratch);
median = scratch[scratch.length/2];
mean = sum/Float.valueOf(length);
/* shift peek array */
for (int j=0;j<3-1;j++){
onset_peek[j] = onset_peek[j+1];
}
/* calculate new peek value */
onset_peek[2] = (float) (onset_proc[win_post] - median - mean * threshold);
boolean isPeak = isPeak(1);
lastPeekValue = onset;
return isPeak;
} |
Modified version for real time, moving mean adaptive threshold this
method is slightly more permissive than the off-LineWavelet one, and yields to
an increase of false positives.
@param onset
The new onset value.
@return True if a peak is detected, false otherwise.
| PeakPicker::pickPeak | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | Apache-2.0 |
public float getLastPeekValue() {
return lastPeekValue;
} |
@return The value of the last detected peak, or zero.
| PeakPicker::getLastPeekValue | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | Apache-2.0 |
private boolean isPeak(int index) {
return ( onset_peek[index] > onset_peek[index - 1] &&
onset_peek[index] > onset_peek[index + 1] &&
onset_peek[index] > 0.);
} |
Returns true if the onset is a peak.
@param index
the index in onset_peak to check.
@return True if the onset is a peak, false otherwise.
| PeakPicker::isPeak | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/PeakPicker.java | Apache-2.0 |
public FFMPEGDownloader(){
String filename = operatingSystemName() + "_" + processorArchitecture() + "_ffmpeg" + suffix();
url = url + filename;
String tempDirectory = System.getProperty("java.io.tmpdir");
String saveTo = new File(tempDirectory,filename).getAbsolutePath();
if(new File(saveTo).exists() && new File(saveTo).length() > 1000){
LOG.info("Found an already download ffmpeg static binary: " + saveTo);
ffmpegBinary = saveTo;
}else{
LOG.info("Started downloading an ffmpeg static binary from " + url + " to " + saveTo );
downloadExecutable(saveTo);
if(new File(saveTo).exists() && new File(saveTo).length() > 1000){
LOG.info("Downloaded an ffmpeg static binary. Stored at: " + saveTo);
//make it executable
new File(saveTo).setExecutable(true);
ffmpegBinary = saveTo;
}else{
//Unable to download or unknown architecture
LOG.warning("Unable to find or download an ffmpeg static binary. " + filename);
ffmpegBinary = null;
}
}
} |
A new FFMPEGDownloader
| FFMPEGDownloader::FFMPEGDownloader | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/FFMPEGDownloader.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/FFMPEGDownloader.java | Apache-2.0 |
public String ffmpegBinary(){
if(ffmpegBinary!=null){
return ffmpegBinary.replace(suffix(), "");
}
return null;
} |
The path of the downloaded ffmpeg binary or null
@return The path of the downloaded ffmpeg binary or null
| FFMPEGDownloader::ffmpegBinary | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/FFMPEGDownloader.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/FFMPEGDownloader.java | Apache-2.0 |
public BiQuadFilter(double b1, double b2, double b3, double a2, double a3) {
this.a2 = a2;
this.a3 = a3;
this.b1 = b1;
this.b2 = b2;
this.b3 = b3;
this.i1 = 0.;
this.i2 = 0.;
this.o1 = 0.;
this.o2 = 0.;
} |
Create a new biquad filter
@param b1 first
@param b2 second
@param b3 third
@param a2 a first
@param a3 a second
| BiQuadFilter::BiQuadFilter | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/BiQuadFilter.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/BiQuadFilter.java | Apache-2.0 |
public static String sanitizeResource(String inputResource) {
if (inputResource.toLowerCase().endsWith("pls")) {
inputResource = parsePLS(inputResource);
} else if (inputResource.toLowerCase().endsWith("m3u")) {
inputResource = parseM3U(inputResource);
} else if (inputResource.toLowerCase().endsWith("asx")){
inputResource = parseASX(inputResource);
} else if (inputResource.toLowerCase().endsWith("xspf")){
inputResource = parseXSPF(inputResource);
}
return inputResource;
} |
Returns a more practical audio resource name. E.g. if
http://stream.com/stream.pls is given, the PLS-file is parsed and the
first audio file is returned. It supports PLS, M3U, AXS and XSPF"
@param inputResource
The input resource, a file, URL, PLS-file or M3U-file.
@return A more practical audio resource name.
| AudioResourceUtils::sanitizeResource | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | Apache-2.0 |
public static String parsePLS(String inputUrl) {
String inputFile = "";
try {
String plsContents = readTextFromUrl(new URL(inputUrl));
for (String line : plsContents.split("\n")) {
if (line.startsWith("File1=")) {
inputFile = line.replace("File1=", "").trim();
break;
}
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return inputFile;
} |
Parses the PLS file and returns the first file name.
@param inputUrl
The input PLS file.
@return The first file name in the PLS playlist.
| AudioResourceUtils::parsePLS | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | Apache-2.0 |
public static String parseM3U(String inputUrl) {
String inputFile = "";
try {
String plsContents = readTextFromUrl(new URL(inputUrl));
for (String line : plsContents.split("\n")) {
if (!line.trim().isEmpty() && !line.trim().startsWith("#")) {
inputFile = line.trim();
break;
}
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return inputFile;
} |
Parses the M3U file and returns the first file name.
@param inputUrl
The input M3U file.
@return The first file name in the M3U play list.
| AudioResourceUtils::parseM3U | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | Apache-2.0 |
public static String readTextFromUrl(URL url) {
StringBuffer fubber = new StringBuffer();
try {
BufferedReader in = new BufferedReader(new InputStreamReader(
url.openStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) {
fubber.append(inputLine).append("\n");
}
in.close();
} catch (IOException exception) {
exception.printStackTrace();
}
return fubber.toString();
} |
Return the text of the file with the given URL. E.g. if
http://test.be/text.txt is given the contents of text.txt is returned.
@param url
The URL.
@return The contents of the file.
| AudioResourceUtils::readTextFromUrl | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/AudioResourceUtils.java | Apache-2.0 |
public static int getNumberOfProcessors() {
return Runtime.getRuntime().availableProcessors();
} |
Returns the number of available processors.
@return number of available processors
| CustomThreadFactory::getNumberOfProcessors | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int getNumberOfThreads() {
return NTHREADS;
} |
Returns the current number of threads.
@return the current number of threads.
| CustomThreadFactory::getNumberOfThreads | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void setNumberOfThreads(int n) {
NTHREADS = prevPow2(n);
} |
Sets the number of threads. If n is not a power-of-two number, then the
number of threads is set to the closest power-of-two number less than n.
@param n The number of threads
| CustomThreadFactory::setNumberOfThreads | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int getThreadsBeginN_1D_FFT_2Threads() {
return THREADS_BEGIN_N_1D_FFT_2THREADS;
} |
Returns the minimal size of 1D data for which two threads are used.
@return the minimal size of 1D data for which two threads are used
| CustomThreadFactory::getThreadsBeginN_1D_FFT_2Threads | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int getThreadsBeginN_1D_FFT_4Threads() {
return THREADS_BEGIN_N_1D_FFT_4THREADS;
} |
Returns the minimal size of 1D data for which four threads are used.
@return the minimal size of 1D data for which four threads are used
| CustomThreadFactory::getThreadsBeginN_1D_FFT_4Threads | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int getThreadsBeginN_2D() {
return THREADS_BEGIN_N_2D;
} |
Returns the minimal size of 2D data for which threads are used.
@return the minimal size of 2D data for which threads are used
| CustomThreadFactory::getThreadsBeginN_2D | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int getThreadsBeginN_3D() {
return THREADS_BEGIN_N_3D;
} |
Returns the minimal size of 3D data for which threads are used.
@return the minimal size of 3D data for which threads are used
| CustomThreadFactory::getThreadsBeginN_3D | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void setThreadsBeginN_1D_FFT_2Threads(int n) {
if (n < 512) {
THREADS_BEGIN_N_1D_FFT_2THREADS = 512;
} else {
THREADS_BEGIN_N_1D_FFT_2THREADS = n;
}
} |
Sets the minimal size of 1D data for which two threads are used.
@param n
the minimal size of 1D data for which two threads are used
| CustomThreadFactory::setThreadsBeginN_1D_FFT_2Threads | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void setThreadsBeginN_1D_FFT_4Threads(int n) {
if (n < 512) {
THREADS_BEGIN_N_1D_FFT_4THREADS = 512;
} else {
THREADS_BEGIN_N_1D_FFT_4THREADS = n;
}
} |
Sets the minimal size of 1D data for which four threads are used.
@param n
the minimal size of 1D data for which four threads are used
| CustomThreadFactory::setThreadsBeginN_1D_FFT_4Threads | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void setThreadsBeginN_2D(int n) {
THREADS_BEGIN_N_2D = n;
} |
Sets the minimal size of 2D data for which threads are used.
@param n
the minimal size of 2D data for which threads are used
| CustomThreadFactory::setThreadsBeginN_2D | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void setThreadsBeginN_3D(int n) {
THREADS_BEGIN_N_3D = n;
} |
Sets the minimal size of 3D data for which threads are used.
@param n
the minimal size of 3D data for which threads are used
| CustomThreadFactory::setThreadsBeginN_3D | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void resetThreadsBeginN_FFT() {
THREADS_BEGIN_N_1D_FFT_2THREADS = 8192;
THREADS_BEGIN_N_1D_FFT_4THREADS = 65536;
} |
Resets the minimal size of 1D data for which two and four threads are
used.
| CustomThreadFactory::resetThreadsBeginN_FFT | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void resetThreadsBeginN() {
THREADS_BEGIN_N_2D = 65536;
THREADS_BEGIN_N_3D = 65536;
} |
Resets the minimal size of 2D and 3D data for which threads are used.
| CustomThreadFactory::resetThreadsBeginN | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int nextPow2(int x) {
if (x < 1)
throw new IllegalArgumentException("x must be greater or equal 1");
if ((x & (x - 1)) == 0) {
return x; // x is already a power-of-two number
}
x |= (x >>> 1);
x |= (x >>> 2);
x |= (x >>> 4);
x |= (x >>> 8);
x |= (x >>> 16);
x |= (x >>> 32);
return x + 1;
} |
Returns the closest power-of-two number greater than or equal to x.
@param x the number to process
@return the closest power-of-two number greater than or equal to x
| CustomThreadFactory::nextPow2 | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static int prevPow2(int x) {
if (x < 1)
throw new IllegalArgumentException("x must be greater or equal 1");
return (int) Math.pow(2, Math.floor(Math.log(x) / Math.log(2)));
} |
Returns the closest power-of-two number less than or equal to x.
@param x the number to process
@return the closest power-of-two number less then or equal to x
| CustomThreadFactory::prevPow2 | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static boolean isPowerOf2(int x) {
if (x <= 0)
return false;
else
return (x & (x - 1)) == 0;
} |
Checks if x is a power-of-two number.
@param x the number to process
@return true if x is a power-of-two number
| CustomThreadFactory::isPowerOf2 | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void sleep(long millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException e) {
e.printStackTrace();
}
} |
Causes the currently executing thread to sleep (temporarily cease
execution) for the specified number of milliseconds.
@param millis the number to millis to sleep
| CustomThreadFactory::sleep | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static Future<?> submit(Runnable task) {
return THREAD_POOL.submit(task);
} |
Submits a Runnable task for execution and returns a Future representing
that task.
@param task a Runnable task for execution
@return a Future representing the task
| CustomThreadFactory::submit | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public static void waitForCompletion(Future<?>[] futures) {
int size = futures.length;
try {
for (int j = 0; j < size; j++) {
futures[j].get();
}
} catch (ExecutionException ex) {
ex.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
} |
Waits for all threads to complete computation.
@param futures The futures which need completion.
| CustomThreadFactory::waitForCompletion | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/ConcurrencyUtils.java | Apache-2.0 |
public HammingWindow() {
super();
} |
Constructs a Hamming window.
| HammingWindow::HammingWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/HammingWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/HammingWindow.java | Apache-2.0 |
public LanczosWindow() {
} |
A Lanczos window function.
@author Damien Di Fede
@author Corban Brook
@see <a
href="http://en.wikipedia.org/wiki/Window_function#Lanczos_window">The
Lanczos Window</a>
public class LanczosWindow extends WindowFunction {
/** Constructs a Lanczos window. | LanczosWindow::LanczosWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/LanczosWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/LanczosWindow.java | Apache-2.0 |
public BartlettHannWindow()
{
} |
A Bartlett-Hann window function.
@author Damien Di Fede
@author Corban Brook
@see <a href="http://en.wikipedia.org/wiki/Window_function#Bartlett.E2.80.93Hann_window">The Bartlett-Hann Window</a>
public class BartlettHannWindow extends WindowFunction
{
/** Constructs a Bartlett-Hann window. | BartlettHannWindow::BartlettHannWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/BartlettHannWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/BartlettHannWindow.java | Apache-2.0 |
public FFT(final int size) {
this(size,null);
} |
Create a new fft
@param size of this size
| FFT::FFT | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public FFT(final int size, final WindowFunction windowFunction){
fft = new FloatFFT(size);
fftSize = size;
this.windowFunction = windowFunction;
if(windowFunction==null)
window = null;
else
window = windowFunction.generateCurve(size);
} |
Create a new fft of the specified size. Apply the specified window on the samples before a forward transform.
arning: the window is not applied in reverse when a backwards transform is requested.
@param size The size of the fft.
@param windowFunction Apply the specified window on the samples before a forward transform.
arning: the window is not applied in reverse when a backwards transform is requested.
| FFT::FFT | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void forwardTransform(final float[] data) {
if(windowFunction!=null){
for(int i = 0 ; i < data.length ; i++){
data[i] = data[i] * window[i];
}
//windowFunction.apply(data);
}
fft.realForward(data);
} |
Computes forward DFT.
@param data
data to transform.
| FFT::forwardTransform | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void complexForwardTransform(final float[] data) {
if(windowFunction!=null){
for(int i = 0 ; i < data.length ; i++){
data[i] = data[i] * window[i];
}
//windowFunction.apply(data);
}
fft.complexForward(data);
} |
do a complex forward transform
@param data do a complex forward transform on these complex numbers
| FFT::complexForwardTransform | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void backwardsTransform(final float[] data) {
fft.realInverse(data, true);
} |
Computes inverse DFT.
Warning, does not reverse the window function.
@param data
data to transform
| FFT::backwardsTransform | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public double binToHz(final int binIndex, final float sampleRate) {
return binIndex * sampleRate / (double) fftSize;
} |
Calculate the frequency of the bin.
@param binIndex The index of the bin.
@param sampleRate The sample rate of the audio.
@return The frequency in Hz of the bin.
| FFT::binToHz | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public int size(){
return fftSize;
} |
The size of the fft.
@return The size of the fft.
| FFT::size | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public float modulus(final float[] data, final int index) {
final int realIndex = 2 * index;
final int imgIndex = 2 * index + 1;
final float modulus = data[realIndex] * data[realIndex] + data[imgIndex] * data[imgIndex];
return (float) Math.sqrt(modulus);
} |
Returns the modulus of the element at index bufferCount. The modulus,
magnitude or absolute value is (a²+b²) ^ 0.5 with a being the real part
and b the imaginary part of a complex number.
@param data
The FFT transformed data.
@param index
The index of the element.
@return The modulus, magnitude or absolute value of the element at index
bufferCount
| FFT::modulus | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void modulus(final float[] data, final float[] amplitudes) {
assert data.length / 2 == amplitudes.length;
for (int i = 0; i < amplitudes.length; i++) {
amplitudes[i] = modulus(data, i);
}
} |
Calculates the the modulus for each element in data and stores the result
in amplitudes.
@param data
The input data.
@param amplitudes
The output modulus info or amplitude.
| FFT::modulus | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void powerPhaseFFT(float[] data,float[] power, float[] phase) {
assert data.length / 2 == power.length;
assert data.length / 2 == phase.length;
if(windowFunction!=null){
windowFunction.apply(data);
}
fft.realForward(data);
powerAndPhaseFromFFT(data, power, phase);
} |
Computes an FFT and converts the results to polar coordinates (power and
phase). Both the power and phase arrays must be the same length, data
should be double the length.
@param data
The input audio signal.
@param power
The power (modulus) of the data.
@param phase
The phase of the data
| FFT::powerPhaseFFT | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void powerAndPhaseFromFFT(float[] data,float[] power, float[] phase){
phase[0] = (float) Math.PI;
power[0] = -data[0];
for (int i = 1; i < power.length; i++) {
int realIndex = 2 * i;
int imgIndex = 2 * i + 1;
power[i] = (float) Math.sqrt(data[realIndex] * data[realIndex] + data[imgIndex] * data[imgIndex]);
phase[i] = (float) Math.atan2(data[imgIndex], data[realIndex]);
}
} |
Returns magnitude (or power) and phase for the FFT transformed data.
@param data The FFT transformed data.
@param power The array where the magnitudes or powers are going to be stored. It is half the length of data (FFT size).
@param phase The array where the phases are going to be stored. It is half the length of data (FFT size).
| FFT::powerAndPhaseFromFFT | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void powerPhaseFFTBeatRootOnset(float[] data,float[] power, float[] phase) {
powerPhaseFFT(data, power, phase);
power[0] = (float) Math.sqrt(data[0] * data[0] + data[1] * data[1]);
} |
Beatroot expects a different first power element
@param data The FFT transformed data.
@param power The array where the magnitudes or powers are going to be stored. It is half the length of data (FFT size).
@param phase The array where the phases are going to be stored. It is half the length of data (FFT size).
| FFT::powerPhaseFFTBeatRootOnset | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
public void multiply(float[] data, float[] other){
assert data.length == other.length;
if(data.length!=other.length){
throw new IllegalArgumentException("Both arrays with imaginary numbers shouldb e of equal length");
}
for (int i = 1; i < data.length-1; i+=2) {
int realIndex = i;
int imgIndex = i + 1;
float tempReal = data[realIndex] * other[realIndex] + -1 * data[imgIndex] * other[imgIndex];
float tempImg = data[realIndex] * other[imgIndex] + data[imgIndex] * other[realIndex];
data[realIndex] = tempReal;
data[imgIndex] = tempImg;
//fix by perfecthu
//data[realIndex] = data[realIndex] * other[realIndex] + -1 * data[imgIndex] * other[imgIndex];
//data[imgIndex] = data[realIndex] * other[imgIndex] + data[imgIndex] * other[realIndex];
}
} |
Multiplies to arrays containing imaginary numbers. The data in the first argument
is modified! The real part is stored at <code>2*i</code>, the imaginary part <code>2*i+i</code>
@param data The array with imaginary numbers that is modified.
@param other The array with imaginary numbers that is not modified.
Data and other need to be the same length.
| FFT::multiply | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FFT.java | Apache-2.0 |
protected WindowFunction() {
} |
Construct a new window.
| WindowFunction::WindowFunction | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/WindowFunction.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/WindowFunction.java | Apache-2.0 |
public void apply(float[] samples) {
this.length = samples.length;
for (int n = 0; n < samples.length; n++) {
samples[n] *= value(samples.length, n);
}
} |
Apply the window function to a sample buffer.
@param samples
a sample buffer
| WindowFunction::apply | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/WindowFunction.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/WindowFunction.java | Apache-2.0 |
public float[] generateCurve(int length) {
float[] samples = new float[length];
for (int n = 0; n < length; n++) {
samples[n] = value(length, n);
}
return samples;
} |
Generates the curve of the window function.
@param length
the length of the window
@return the shape of the window function
| WindowFunction::generateCurve | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/WindowFunction.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/WindowFunction.java | Apache-2.0 |
public BlackmanWindow(float alpha) {
this.alpha = alpha;
} |
Constructs a Blackman window.
@param alpha The Blackman alpha parameter
| BlackmanWindow::BlackmanWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/BlackmanWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/BlackmanWindow.java | Apache-2.0 |
public BlackmanWindow() {
this(0.16f);
} |
Constructs a Blackman window.
@param alpha The Blackman alpha parameter
public BlackmanWindow(float alpha) {
this.alpha = alpha;
}
/** Constructs a Blackman window with a default alpha value of 0.16 | BlackmanWindow::BlackmanWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/BlackmanWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/BlackmanWindow.java | Apache-2.0 |
public CosineWindow() {
} |
A Cosine window function.
@author Damien Di Fede
@author Corban Brook
@see <a href="http://en.wikipedia.org/wiki/Window_function#Cosine_window">The
Cosine Window</a>
public class CosineWindow extends WindowFunction {
/** Constructs a Cosine window. | CosineWindow::CosineWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/CosineWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/CosineWindow.java | Apache-2.0 |
public BartlettWindow()
{
} |
A Bartlett window function.
@author Damien Di Fede
@author Corban Brook
@see <a href="http://en.wikipedia.org/wiki/Window_function#Bartlett_window_.28zero_valued_end-points.29">The Bartlett Window</a>
public class BartlettWindow extends WindowFunction
{
/** Constructs a Bartlett window. | BartlettWindow::BartlettWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/BartlettWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/BartlettWindow.java | Apache-2.0 |
public RectangularWindow() {
} |
A Rectangular window function A Rectangular window is equivalent to using no
window at all.
@author Damien Di Fede
@author Corban Brook
@see <a
href="http://en.wikipedia.org/wiki/Window_function#Rectangular_window">The
Rectangular Window</a>
public class RectangularWindow extends WindowFunction {
/** Constructs a Rectangular window. | RectangularWindow::RectangularWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/RectangularWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/RectangularWindow.java | Apache-2.0 |
public HannWindow() {
} |
A Hann window function.
@author Damien Di Fede
@author Corban Brook
@see <a href="http://en.wikipedia.org/wiki/Window_function#Hann_window">The
Hann Window</a>
public class HannWindow extends WindowFunction {
/** Constructs a Hann window. | HannWindow::HannWindow | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/HannWindow.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/HannWindow.java | Apache-2.0 |
public FloatFFT(int n) {
if (n < 1) {
throw new IllegalArgumentException("n must be greater than 0");
}
this.n = n;
if (!ConcurrencyUtils.isPowerOf2(n)) {
if (getReminder(n, factors) >= 211) {
plan = Plans.BLUESTEIN;
nBluestein = ConcurrencyUtils.nextPow2(n * 2 - 1);
bk1 = new float[2 * nBluestein];
bk2 = new float[2 * nBluestein];
this.ip = new int[2 + (int) Math.ceil(2 + (1 << (int) (Math.log(nBluestein + 0.5) / Math.log(2)) / 2))];
this.w = new float[nBluestein];
int twon = 2 * nBluestein;
nw = ip[0];
if (twon > (nw << 2)) {
nw = twon >> 2;
makewt(nw);
}
nc = ip[1];
if (nBluestein > (nc << 2)) {
nc = nBluestein >> 2;
makect(nc, w, nw);
}
bluesteini();
} else {
plan = Plans.MIXED_RADIX;
wtable = new float[4 * n + 15];
wtable_r = new float[2 * n + 15];
cffti();
rffti();
}
} else {
plan = Plans.SPLIT_RADIX;
this.ip = new int[2 + (int) Math.ceil(2 + (1 << (int) (Math.log(n + 0.5) / Math.log(2)) / 2))];
this.w = new float[n];
int twon = 2 * n;
nw = ip[0];
if (twon > (nw << 2)) {
nw = twon >> 2;
makewt(nw);
}
nc = ip[1];
if (n > (nc << 2)) {
nc = n >> 2;
makect(nc, w, nw);
}
}
} |
Creates new instance of FloatFFT.
@param n
size of data
| FloatFFT::FloatFFT | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void complexForward(float[] a) {
complexForward(a, 0);
} |
Computes 1D forward DFT of complex data leaving the result in
<code>a</code>. Complex number is stored as two float values in
sequence: the real and imaginary part, i.e. the size of the input array
must be greater or equal 2*n. The physical layout of the input data has
to be as follows:<br>
<pre>
a[2*k] = Re[k],
a[2*k+1] = Im[k], 0<=k<n
</pre>
@param a
data to transform
| FloatFFT::complexForward | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void complexForward(float[] a, int offa) {
if (n == 1)
return;
switch (plan) {
case SPLIT_RADIX:
cftbsub(2 * n, a, offa, ip, nw, w);
break;
case MIXED_RADIX:
cfftf(a, offa, -1);
break;
case BLUESTEIN:
bluestein_complex(a, offa, -1);
break;
}
} |
Computes 1D forward DFT of complex data leaving the result in
<code>a</code>. Complex number is stored as two float values in
sequence: the real and imaginary part, i.e. the size of the input array
must be greater or equal 2*n. The physical layout of the input data has
to be as follows:<br>
<pre>
a[offa+2*k] = Re[k],
a[offa+2*k+1] = Im[k], 0<=k<n
</pre>
@param a
data to transform
@param offa
index of the first element in array <code>a</code>
| FloatFFT::complexForward | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void complexInverse(float[] a, boolean scale) {
complexInverse(a, 0, scale);
} |
Computes 1D inverse DFT of complex data leaving the result in
<code>a</code>. Complex number is stored as two float values in
sequence: the real and imaginary part, i.e. the size of the input array
must be greater or equal 2*n. The physical layout of the input data has
to be as follows:<br>
<pre>
a[2*k] = Re[k],
a[2*k+1] = Im[k], 0<=k<n
</pre>
@param a
data to transform
@param scale
if true then scaling is performed
| FloatFFT::complexInverse | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void complexInverse(float[] a, int offa, boolean scale) {
if (n == 1)
return;
switch (plan) {
case SPLIT_RADIX:
cftfsub(2 * n, a, offa, ip, nw, w);
break;
case MIXED_RADIX:
cfftf(a, offa, +1);
break;
case BLUESTEIN:
bluestein_complex(a, offa, 1);
break;
}
if (scale) {
scale(n, a, offa, true);
}
} |
Computes 1D inverse DFT of complex data leaving the result in
<code>a</code>. Complex number is stored as two float values in
sequence: the real and imaginary part, i.e. the size of the input array
must be greater or equal 2*n. The physical layout of the input data has
to be as follows:<br>
<pre>
a[offa+2*k] = Re[k],
a[offa+2*k+1] = Im[k], 0<=k<n
</pre>
@param a
data to transform
@param offa
index of the first element in array <code>a</code>
@param scale
if true then scaling is performed
| FloatFFT::complexInverse | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void realForward(float[] a) {
realForward(a, 0);
} |
Computes 1D forward DFT of real data leaving the result in <code>a</code>
. The physical layout of the output data is as follows:<br>
if n is even then
<pre>
a[2*k] = Re[k], 0<=k<n/2
a[2*k+1] = Im[k], 0<k<n/2
a[1] = Re[n/2]
</pre>
if n is odd then
<pre>
a[2*k] = Re[k], 0<=k<(n+1)/2
a[2*k+1] = Im[k], 0<k<(n-1)/2
a[1] = Im[(n-1)/2]
</pre>
This method computes only half of the elements of the real transform. The
other half satisfies the symmetry condition. If you want the full real
forward transform, use <code>realForwardFull</code>. To get back the
original data, use <code>realInverse</code> on the output of this method.
@param a
data to transform
| FloatFFT::realForward | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void realForward(float[] a, int offa) {
if (n == 1)
return;
switch (plan) {
case SPLIT_RADIX:
float xi;
if (n > 4) {
cftfsub(n, a, offa, ip, nw, w);
rftfsub(n, a, offa, nc, w, nw);
} else if (n == 4) {
cftx020(a, offa);
}
xi = a[offa] - a[offa + 1];
a[offa] += a[offa + 1];
a[offa + 1] = xi;
break;
case MIXED_RADIX:
rfftf(a, offa);
for (int k = n - 1; k >= 2; k--) {
int idx = offa + k;
float tmp = a[idx];
a[idx] = a[idx - 1];
a[idx - 1] = tmp;
}
break;
case BLUESTEIN:
bluestein_real_forward(a, offa);
break;
}
} |
Computes 1D forward DFT of real data leaving the result in <code>a</code>
. The physical layout of the output data is as follows:<br>
if n is even then
<pre>
a[offa+2*k] = Re[k], 0<=k<n/2
a[offa+2*k+1] = Im[k], 0<k<n/2
a[offa+1] = Re[n/2]
</pre>
if n is odd then
<pre>
a[offa+2*k] = Re[k], 0<=k<(n+1)/2
a[offa+2*k+1] = Im[k], 0<k<(n-1)/2
a[offa+1] = Im[(n-1)/2]
</pre>
This method computes only half of the elements of the real transform. The
other half satisfies the symmetry condition. If you want the full real
forward transform, use <code>realForwardFull</code>. To get back the
original data, use <code>realInverse</code> on the output of this method.
@param a
data to transform
@param offa
index of the first element in array <code>a</code>
| FloatFFT::realForward | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void realForwardFull(float[] a) {
realForwardFull(a, 0);
} |
Computes 1D forward DFT of real data leaving the result in <code>a</code>
. This method computes the full real forward transform, i.e. you will get
the same result as from <code>complexForward</code> called with all
imaginary parts equal 0. Because the result is stored in <code>a</code>,
the size of the input array must greater or equal 2*n, with only the
first n elements filled with real data. To get back the original data,
use <code>complexInverse</code> on the output of this method.
@param a
data to transform
| FloatFFT::realForwardFull | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void realForwardFull(final float[] a, final int offa) {
final int twon = 2 * n;
switch (plan) {
case SPLIT_RADIX:
realForward(a, offa);
int nthreads = ConcurrencyUtils.getNumberOfThreads();
if ((nthreads > 1) && (n / 2 > ConcurrencyUtils.getThreadsBeginN_1D_FFT_2Threads())) {
Future<?>[] futures = new Future[nthreads];
int k = n / 2 / nthreads;
for (int i = 0; i < nthreads; i++) {
final int firstIdx = i * k;
final int lastIdx = (i == (nthreads - 1)) ? n / 2 : firstIdx + k;
futures[i] = ConcurrencyUtils.submit(new Runnable() {
public void run() {
int idx1, idx2;
for (int k = firstIdx; k < lastIdx; k++) {
idx1 = 2 * k;
idx2 = offa + ((twon - idx1) % twon);
a[idx2] = a[offa + idx1];
a[idx2 + 1] = -a[offa + idx1 + 1];
}
}
});
}
ConcurrencyUtils.waitForCompletion(futures);
} else {
int idx1, idx2;
for (int k = 0; k < n / 2; k++) {
idx1 = 2 * k;
idx2 = offa + ((twon - idx1) % twon);
a[idx2] = a[offa + idx1];
a[idx2 + 1] = -a[offa + idx1 + 1];
}
}
a[offa + n] = -a[offa + 1];
a[offa + 1] = 0;
break;
case MIXED_RADIX:
rfftf(a, offa);
int m;
if (n % 2 == 0) {
m = n / 2;
} else {
m = (n + 1) / 2;
}
for (int k = 1; k < m; k++) {
int idx1 = offa + twon - 2 * k;
int idx2 = offa + 2 * k;
a[idx1 + 1] = -a[idx2];
a[idx1] = a[idx2 - 1];
}
for (int k = 1; k < n; k++) {
int idx = offa + n - k;
float tmp = a[idx + 1];
a[idx + 1] = a[idx];
a[idx] = tmp;
}
a[offa + 1] = 0;
break;
case BLUESTEIN:
bluestein_real_full(a, offa, -1);
break;
}
} |
Computes 1D forward DFT of real data leaving the result in <code>a</code>
. This method computes the full real forward transform, i.e. you will get
the same result as from <code>complexForward</code> called with all
imaginary part equal 0. Because the result is stored in <code>a</code>,
the size of the input array must greater or equal 2*n, with only the
first n elements filled with real data. To get back the original data,
use <code>complexInverse</code> on the output of this method.
@param a
data to transform
@param offa
index of the first element in array <code>a</code>
| FloatFFT::realForwardFull | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
public void realInverse(float[] a, boolean scale) {
realInverse(a, 0, scale);
} |
Computes 1D inverse DFT of real data leaving the result in <code>a</code>
. The physical layout of the input data has to be as follows:<br>
if n is even then
<pre>
a[2*k] = Re[k], 0<=k<n/2
a[2*k+1] = Im[k], 0<k<n/2
a[1] = Re[n/2]
</pre>
if n is odd then
<pre>
a[2*k] = Re[k], 0<=k<(n+1)/2
a[2*k+1] = Im[k], 0<k<(n-1)/2
a[1] = Im[(n-1)/2]
</pre>
This method computes only half of the elements of the real transform. The
other half satisfies the symmetry condition. If you want the full real
inverse transform, use <code>realInverseFull</code>.
@param a
data to transform
@param scale
if true then scaling is performed
| FloatFFT::realInverse | java | ZTFtrue/MonsterMusic | app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | https://github.com/ZTFtrue/MonsterMusic/blob/master/app/src/main/java/be/tarsos/dsp/util/fft/FloatFFT.java | Apache-2.0 |
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