/**
* Copyright efishocean ( http://wonderfl.net/user/efishocean )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/v2G1
*/
package {
import flash.display.Sprite;
import flash.media.Sound;
import flash.event.SampleDataEvent;
import flash.event.Event;
import flash.utils.ByteArray;
import flash.net.URLRequest;
public class FlashTest extends Sprite {
private var snd:Sound = new Sound();
private var dynSnd:Sound = new Souind();
private var LEN:uint = 256;
private var fft:FFT = new FFT(256,1);
public function FlashTest() {
// write as3 code here..
snd.addEventListenner("complete",onComplete);
dynSnd.addEventListenner("sampleData",onSampleData);
snd.load( new URLRequest( "http://www.duobiduo.com/tracks/10/mp3" ) );
}
private function onComplete(e:Event):void
{
dynSnd.play();
}
private function onSampleData(e:SampleDataEvent):void
{
var bytes:ByteArray = new ByteArray();
//extract samples
snd.extract(bytes,2048);
//format to vector
bytes.postion = 0;
var data:Vector.<Number> = new Vector.<Number>(LEN*2,true);
for(var i:uint=0;i<LEN;++i)
{
//left
data.push(bytes.readFloat());
//right
data.push(bytes.readFloat());
}
// FFT process
fft.transform(data);
//compute spectrum
var sp:Vector.<Number> =new Vector.<Number>(LEN*2,true);
for(i=0;i<LEN;++i)
{
sp[i] = Math.sqrt(Math.abs(data[i]));
sp[i+LEN] = Math.sqrt(Math.abs(data[i+LEN] ));
}
//draw spec
this.graphic.beginFill(1,0xff00ff);
// this.graphic.moveTo(0,0);
for(i=0;i<LEN*2;++i)
{
this.graphic.drawRect(i,0,1,sp[i]);
}
this.graphic.endFill();
//use SoundMix computeSpectrum
SoundMixer.computeSpectrum(bytes, true, 0);
//play while sampleData event need
e.data.writeBytes(bytes,0,bytes.length);
}
}
/**
* Fast Fourier Transformer. Ported from Java version of Karl Helgason
*
* @author Efishocean
* @version 1.09.0422
*/
public final class FFT
{
private var _w:Vector.<Number>;
private var _fftFrameSize:int;
private var _sign:int;
private var _bitm_array:Vector.<int>;
private var _fftFrameSize2:int;
// Sign = 1 is FFT, -1 is IFFT (inverse FFT)
// Data = Interlaced double array to be transformed.
// The order is: real (sin), complex (cos)
// Framesize must be power of 2
public function FFT(fftFrameSize:int, sign:int=1)
{
_w = computeTwiddleFactors(fftFrameSize, sign);
_fftFrameSize = fftFrameSize;
_sign = sign;
_fftFrameSize2 = fftFrameSize << 1;
// Pre-process Bit-Reversal
_bitm_array = new Vector.<int>(_fftFrameSize2);
for (var i:int = 2; i < _fftFrameSize2; i += 2)
{
var k:int;
var bitm:int;
for (bitm = 2, k = 0; bitm < _fftFrameSize2; bitm <<= 1)
{
if ((i & bitm) != 0)
k++;
k <<= 1;
}
_bitm_array[i] = k;
}
}
public function transform( data:Vector.<Number>):void
{
bitreversal(data);
calc(_fftFrameSize, data, _sign, _w);
}
private function computeTwiddleFactors(fftFrameSize:int, sign:int):Vector.<Number>
{
var imax:int = int (Math.log(fftFrameSize) / Math.LN2);// .log(2.));
var warray:Vector.<Number>= new Vector.<Number>((fftFrameSize - 1) * 4);
var w_index:int = 0;
for (var i:int = 0, nstep:int = 2; i < imax; i++)
{
var kmax:int = nstep;
nstep <<= 1;
var wr:Number = 1.0;
var wi:Number = 0.0;
var arg:Number = Math.PI / (kmax >> 1);
var wfr:Number = Math.cos(arg);
var wfi:Number = sign * Math.sin(arg);
for (var k:Number = 0; k < kmax; k += 2)
{
warray[w_index++] = wr;
warray[w_index++] = wi;
var tempr:Number = wr;
wr = tempr * wfr - wi * wfi;
wi = tempr * wfi + wi * wfr;
}
}
// PRECOMPUTATION of wwr1, wwi1 for factor 4 Decomposition (3 * complex
// operators and 8 +/- complex operators)
w_index = 0;
var w_index2:int = warray.length >> 1;
for (i = 0, nstep = 2; i < (imax - 1); i++)
{
kmax = nstep;
nstep *= 2;
var ii:int = w_index + kmax;
for (k = 0; k < kmax; k += 2)
{
wr = warray[w_index++];
wi = warray[w_index++];
var wr1:Number = warray[ii++];
var wi1:Number = warray[ii++];
warray[w_index2++] = wr * wr1 - wi * wi1;
warray[w_index2++] = wr * wi1 + wi * wr1;
}
}
return warray;
}
private function calc( fftFrameSize:int, data:Vector.<Number>, sign:int, w:Vector.<Number>):void
{
const fftFrameSize2:int = fftFrameSize << 1;
var nstep:int = 2;
if (nstep >= fftFrameSize2)
return;
var i:int = nstep - 2;
if (sign == -1)
calcF4F(fftFrameSize, data, i, nstep, w);
else
calcF4I(fftFrameSize, data, i, nstep, w);
}
private function calcF2E( fftFrameSize:int, data:Vector.<Number>, i:int, nstep:int, w:Vector.<Number>):void
{
var kmax:int = nstep;
for (var n:int = 0; n < kmax; n += 2)
{
var wr:Number = w[i++];
var wi:Number = w[i++];
var m:int = n + kmax;
var datam_r:Number = data[m];
var datam_i:Number = data[m + 1];
var datan_r:Number = data[n];
var datan_i:Number = data[n + 1];
var tempr:Number = datam_r * wr - datam_i * wi;
var tempi:Number = datam_r * wi + datam_i * wr;
data[m] = datan_r - tempr;
data[m + 1] = datan_i - tempi;
data[n] = datan_r + tempr;
data[n + 1] = datan_i + tempi;
}
}
// Perform Factor-4 Decomposition with 3 * complex operators and 8 +/-
// complex operators
private function calcF4F( fftFrameSize:int, data:Vector.<Number>, i:int, nstep:int, w:Vector.<Number>):void
{
const fftFrameSize2:int = fftFrameSize << 1; // 2*fftFrameSize;
// Factor-4 Decomposition
var w_len:int = w.length >> 1;
while (nstep < fftFrameSize2)
{
if (nstep << 2 == fftFrameSize2)
{
// Goto Factor-4 Final Decomposition
// calcF4E(data, i, nstep, -1, w);
calcF4FE(fftFrameSize, data, i, nstep, w);
return;
}
var kmax:int = nstep;
var nnstep:int = nstep << 1;
if (nnstep == fftFrameSize2)
{
// Factor-4 Decomposition not possible
calcF2E(fftFrameSize, data, i, nstep, w);
return;
}
nstep <<= 2;
var ii:int = i + kmax;
var iii:int = i + w_len;
i += 2;
ii += 2;
iii += 2;
for (var n:int = 0; n < fftFrameSize2; n += nstep)
{
var m:int = n + kmax;
var datam1_r:Number = data[m];
var datam1_i:Number = data[m + 1];
var datan1_r:Number = data[n];
var datan1_i:Number = data[n + 1];
n += nnstep;
m += nnstep;
var datam2_r:Number = data[m];
var datam2_i:Number = data[m + 1];
var datan2_r:Number = data[n];
var datan2_i:Number = data[n + 1];
var tempr:Number = datam1_r;
var tempi:Number = datam1_i;
datam1_r = datan1_r - tempr;
datam1_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
var n2w1r:Number = datan2_r;
var n2w1i:Number = datan2_i;
var m2ww1r:Number = datam2_r;
var m2ww1i:Number = datam2_i;
tempr = m2ww1r - n2w1r;
tempi = m2ww1i - n2w1i;
datam2_r = datam1_r + tempi;
datam2_i = datam1_i - tempr;
datam1_r = datam1_r - tempi;
datam1_i = datam1_i + tempr;
tempr = n2w1r + m2ww1r;
tempi = n2w1i + m2ww1i;
datan2_r = datan1_r - tempr;
datan2_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
data[m] = datam2_r;
data[m + 1] = datam2_i;
data[n] = datan2_r;
data[n + 1] = datan2_i;
n -= nnstep;
m -= nnstep;
data[m] = datam1_r;
data[m + 1] = datam1_i;
data[n] = datan1_r;
data[n + 1] = datan1_i;
}
for (var k:int = 2; k < kmax; k += 2)
{
var wr:Number = w[i++];
var wi:Number = w[i++];
var wr1:Number = w[ii++];
var wi1:Number = w[ii++];
var wwr1:Number = w[iii++];
var wwi1:Number = w[iii++];
// double wwr1 = wr * wr1 - wi * wi1; // these numbers can be
// precomputed!!!
// double wwi1 = wr * wi1 + wi * wr1;
for (n = k; n < fftFrameSize2; n += nstep) {
m = n + kmax;
datam1_r = data[m];
datam1_i = data[m + 1];
datan1_r = data[n];
datan1_i = data[n + 1];
n += nnstep;
m += nnstep;
datam2_r = data[m];
datam2_i = data[m + 1];
datan2_r = data[n];
datan2_i = data[n + 1];
tempr = datam1_r * wr - datam1_i * wi;
tempi = datam1_r * wi + datam1_i * wr;
datam1_r = datan1_r - tempr;
datam1_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
n2w1r = datan2_r * wr1 - datan2_i * wi1;
n2w1i = datan2_r * wi1 + datan2_i * wr1;
m2ww1r = datam2_r * wwr1 - datam2_i * wwi1;
m2ww1i = datam2_r * wwi1 + datam2_i * wwr1;
tempr = m2ww1r - n2w1r;
tempi = m2ww1i - n2w1i;
datam2_r = datam1_r + tempi;
datam2_i = datam1_i - tempr;
datam1_r = datam1_r - tempi;
datam1_i = datam1_i + tempr;
tempr = n2w1r + m2ww1r;
tempi = n2w1i + m2ww1i;
datan2_r = datan1_r - tempr;
datan2_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
data[m] = datam2_r;
data[m + 1] = datam2_i;
data[n] = datan2_r;
data[n + 1] = datan2_i;
n -= nnstep;
m -= nnstep;
data[m] = datam1_r;
data[m + 1] = datam1_i;
data[n] = datan1_r;
data[n + 1] = datan1_i;
}
}
i += kmax << 1;
}
calcF2E(fftFrameSize, data, i, nstep, w);
}
// Perform Factor-4 Decomposition with 3 * complex operators and 8 +/-
// complex operators
private function calcF4I( fftFrameSize:int, data:Vector.<Number>, i:int, nstep:int, w:Vector.<Number>):void
{
const fftFrameSize2:int = fftFrameSize << 1; // 2*fftFrameSize;
// Factor-4 Decomposition
var w_len:int = w.length >> 1;
while (nstep < fftFrameSize2)
{
if (nstep << 2 == fftFrameSize2)
{
// Goto Factor-4 Final Decomposition
// calcF4E(data, i, nstep, 1, w);
calcF4IE(fftFrameSize, data, i, nstep, w);
return;
}
var kmax:int = nstep;
var nnstep:int = nstep << 1;
if (nnstep == fftFrameSize2)
{
// Factor-4 Decomposition not possible
calcF2E(fftFrameSize, data, i, nstep, w);
return;
}
nstep <<= 2;
var ii:int = i + kmax;
var iii:int = i + w_len;
i += 2;
ii += 2;
iii += 2;
for (var n:int = 0; n < fftFrameSize2; n += nstep)
{
var m:int = n + kmax;
var datam1_r:Number = data[m];
var datam1_i:Number = data[m + 1];
var datan1_r:Number = data[n];
var datan1_i:Number = data[n + 1];
n += nnstep;
m += nnstep;
var datam2_r:Number = data[m];
var datam2_i:Number = data[m + 1];
var datan2_r:Number = data[n];
var datan2_i:Number = data[n + 1];
var tempr:Number = datam1_r;
var tempi:Number = datam1_i;
datam1_r = datan1_r - tempr;
datam1_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
var n2w1r:Number = datan2_r;
var n2w1i:Number = datan2_i;
var m2ww1r:Number = datam2_r;
var m2ww1i:Number = datam2_i;
tempr = n2w1r - m2ww1r;
tempi = n2w1i - m2ww1i;
datam2_r = datam1_r + tempi;
datam2_i = datam1_i - tempr;
datam1_r = datam1_r - tempi;
datam1_i = datam1_i + tempr;
tempr = n2w1r + m2ww1r;
tempi = n2w1i + m2ww1i;
datan2_r = datan1_r - tempr;
datan2_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
data[m] = datam2_r;
data[m + 1] = datam2_i;
data[n] = datan2_r;
data[n + 1] = datan2_i;
n -= nnstep;
m -= nnstep;
data[m] = datam1_r;
data[m + 1] = datam1_i;
data[n] = datan1_r;
data[n + 1] = datan1_i;
}
for (var k:int = 2; k < kmax; k += 2)
{
var wr:Number = w[i++];
var wi:Number = w[i++];
var wr1:Number = w[ii++];
var wi1:Number = w[ii++];
var wwr1:Number = w[iii++];
var wwi1:Number = w[iii++];
// double wwr1 = wr * wr1 - wi * wi1; // these numbers can be
// precomputed!!!
// double wwi1 = wr * wi1 + wi * wr1;
for (n = k; n < fftFrameSize2; n += nstep)
{
m = n + kmax;
datam1_r = data[m];
datam1_i = data[m + 1];
datan1_r = data[n];
datan1_i = data[n + 1];
n += nnstep;
m += nnstep;
datam2_r = data[m];
datam2_i = data[m + 1];
datan2_r = data[n];
datan2_i = data[n + 1];
tempr = datam1_r * wr - datam1_i * wi;
tempi = datam1_r * wi + datam1_i * wr;
datam1_r = datan1_r - tempr;
datam1_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
n2w1r = datan2_r * wr1 - datan2_i * wi1;
n2w1i = datan2_r * wi1 + datan2_i * wr1;
m2ww1r = datam2_r * wwr1 - datam2_i * wwi1;
m2ww1i = datam2_r * wwi1 + datam2_i * wwr1;
tempr = n2w1r - m2ww1r;
tempi = n2w1i - m2ww1i;
datam2_r = datam1_r + tempi;
datam2_i = datam1_i - tempr;
datam1_r = datam1_r - tempi;
datam1_i = datam1_i + tempr;
tempr = n2w1r + m2ww1r;
tempi = n2w1i + m2ww1i;
datan2_r = datan1_r - tempr;
datan2_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
data[m] = datam2_r;
data[m + 1] = datam2_i;
data[n] = datan2_r;
data[n + 1] = datan2_i;
n -= nnstep;
m -= nnstep;
data[m] = datam1_r;
data[m + 1] = datam1_i;
data[n] = datan1_r;
data[n + 1] = datan1_i;
}
}
i += kmax << 1;
}
calcF2E(fftFrameSize, data, i, nstep, w);
}
// Perform Factor-4 Decomposition with 3 * complex operators and 8 +/-
// complex operators
private function calcF4FE( fftFrameSize:int, data:Vector.<Number>, i:int, nstep:int, w:Vector.<Number>):void
{
const fftFrameSize2:int = fftFrameSize << 1; // 2*fftFrameSize;
// Factor-4 Decomposition
var w_len:int = w.length >> 1;
while (nstep < fftFrameSize2)
{
var kmax:int = nstep;
var nnstep:int = nstep << 1;
if (nnstep == fftFrameSize2)
{
// Factor-4 Decomposition not possible
calcF2E(fftFrameSize, data, i, nstep, w);
return;
}
nstep <<= 2;
var ii:int = i + kmax;
var iii:int = i + w_len;
for (var n:int = 0; n < kmax; n += 2)
{
var wr:Number = w[i++];
var wi:Number = w[i++];
var wr1:Number = w[ii++];
var wi1:Number = w[ii++];
var wwr1:Number = w[iii++];
var wwi1:Number = w[iii++];
// double wwr1 = wr * wr1 - wi * wi1; // these numbers can be
// precomputed!!!
// double wwi1 = wr * wi1 + wi * wr1;
var m:int = n + kmax;
var datam1_r:Number = data[m];
var datam1_i:Number = data[m + 1];
var datan1_r:Number = data[n];
var datan1_i:Number = data[n + 1];
n += nnstep;
m += nnstep;
var datam2_r:Number = data[m];
var datam2_i:Number = data[m + 1];
var datan2_r:Number = data[n];
var datan2_i:Number = data[n + 1];
var tempr:Number = datam1_r * wr - datam1_i * wi;
var tempi:Number = datam1_r * wi + datam1_i * wr;
datam1_r = datan1_r - tempr;
datam1_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
var n2w1r:Number = datan2_r * wr1 - datan2_i * wi1;
var n2w1i:Number = datan2_r * wi1 + datan2_i * wr1;
var m2ww1r:Number = datam2_r * wwr1 - datam2_i * wwi1;
var m2ww1i:Number = datam2_r * wwi1 + datam2_i * wwr1;
tempr = m2ww1r - n2w1r;
tempi = m2ww1i - n2w1i;
datam2_r = datam1_r + tempi;
datam2_i = datam1_i - tempr;
datam1_r = datam1_r - tempi;
datam1_i = datam1_i + tempr;
tempr = n2w1r + m2ww1r;
tempi = n2w1i + m2ww1i;
datan2_r = datan1_r - tempr;
datan2_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
data[m] = datam2_r;
data[m + 1] = datam2_i;
data[n] = datan2_r;
data[n + 1] = datan2_i;
n -= nnstep;
m -= nnstep;
data[m] = datam1_r;
data[m + 1] = datam1_i;
data[n] = datan1_r;
data[n + 1] = datan1_i;
}
i += kmax << 1;
}
}
// Perform Factor-4 Decomposition with 3 * complex operators and 8 +/-
// complex operators
private function calcF4IE( fftFrameSize:int, data:Vector.<Number>, i:int, nstep:int, w:Vector.<Number>):void
{
const fftFrameSize2:int = fftFrameSize << 1; // 2*fftFrameSize;
// Factor-4 Decomposition
var w_len:int = w.length >> 1;
while (nstep < fftFrameSize2)
{
var kmax:int = nstep;
var nnstep:int = nstep << 1;
if (nnstep == fftFrameSize2)
{
// Factor-4 Decomposition not possible
calcF2E(fftFrameSize, data, i, nstep, w);
return;
}
nstep <<= 2;
var ii:int = i + kmax;
var iii:int = i + w_len;
for (var n:int = 0; n < kmax; n += 2)
{
var wr:Number = w[i++];
var wi:Number = w[i++];
var wr1:Number = w[ii++];
var wi1:Number = w[ii++];
var wwr1:Number = w[iii++];
var wwi1:Number = w[iii++];
// double wwr1 = wr * wr1 - wi * wi1; // these numbers can be
// precomputed!!!
// double wwi1 = wr * wi1 + wi * wr1;
var m:int = n + kmax;
var datam1_r:Number = data[m];
var datam1_i:Number = data[m + 1];
var datan1_r:Number = data[n];
var datan1_i:Number = data[n + 1];
n += nnstep;
m += nnstep;
var datam2_r:Number = data[m];
var datam2_i:Number = data[m + 1];
var datan2_r:Number = data[n];
var datan2_i:Number = data[n + 1];
var tempr:Number = datam1_r * wr - datam1_i * wi;
var tempi:Number = datam1_r * wi + datam1_i * wr;
datam1_r = datan1_r - tempr;
datam1_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
var n2w1r:Number = datan2_r * wr1 - datan2_i * wi1;
var n2w1i:Number = datan2_r * wi1 + datan2_i * wr1;
var m2ww1r:Number = datam2_r * wwr1 - datam2_i * wwi1;
var m2ww1i:Number = datam2_r * wwi1 + datam2_i * wwr1;
tempr = n2w1r - m2ww1r;
tempi = n2w1i - m2ww1i;
datam2_r = datam1_r + tempi;
datam2_i = datam1_i - tempr;
datam1_r = datam1_r - tempi;
datam1_i = datam1_i + tempr;
tempr = n2w1r + m2ww1r;
tempi = n2w1i + m2ww1i;
datan2_r = datan1_r - tempr;
datan2_i = datan1_i - tempi;
datan1_r = datan1_r + tempr;
datan1_i = datan1_i + tempi;
data[m] = datam2_r;
data[m + 1] = datam2_i;
data[n] = datan2_r;
data[n + 1] = datan2_i;
n -= nnstep;
m -= nnstep;
data[m] = datam1_r;
data[m + 1] = datam1_i;
data[n] = datan1_r;
data[n + 1] = datan1_i;
}
i += kmax << 1;
}
}
private function bitreversal(data:Vector.<Number>):void
{
if (_fftFrameSize < 4)
return;
var inverse:int = _fftFrameSize2 - 2;
for (var i:int = 0; i < _fftFrameSize; i += 4)
{
var k:int = _bitm_array[i];
// Performing Bit-Reversal, even v.s. even, O(2N)
if (i < k)
{
var n:int = i;
var m:int = k;
// COMPLEX: SWAP(data[n], data[m])
// Real Part
var tempr:Number = data[n];
data[n] = data[m];
data[m] = tempr;
// Imagery Part
n++;
m++;
var tempi:Number = data[n];
data[n] = data[m];
data[m] = tempi;
n = inverse - i;
m = inverse - k;
// COMPLEX: SWAP(data[n], data[m])
// Real Part
tempr = data[n];
data[n] = data[m];
data[m] = tempr;
// Imagery Part
n++;
m++;
tempi = data[n];
data[n] = data[m];
data[m] = tempi;
}
// Performing Bit-Reversal, odd v.s. even, O(N)
m = k + _fftFrameSize; // _bitm_array[i+2];
// COMPLEX: SWAP(data[n], data[m])
// Real Part
n = i + 2;
tempr = data[n];
data[n] = data[m];
data[m] = tempr;
// Imagery Part
n++;
m++;
tempi = data[n];
data[n] = data[m];
data[m] = tempi;
}
}
}
