net.sourceforge.jaad.aac.sbr.DCT Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jcodec Show documentation
Show all versions of jcodec Show documentation
Pure Java implementation of video/audio codecs and formats
The newest version!
package net.sourceforge.jaad.aac.sbr;
/**
* This class is part of JAAD ( jaadec.sourceforge.net ) that is distributed
* under the Public Domain license. Code changes provided by the JCodec project
* are distributed under FreeBSD license.
*
* @author in-somnia
*/
class DCT {
private static final int n = 32;
// w_array_real[i] = cos(2*M_PI*i/32)
private static final float[] w_array_real = {
1.000000000000000f, 0.980785279337272f,
0.923879528329380f, 0.831469603195765f,
0.707106765732237f, 0.555570210304169f,
0.382683402077046f, 0.195090284503576f,
0.000000000000000f, -0.195090370246552f,
-0.382683482845162f, -0.555570282993553f,
-0.707106827549476f, -0.831469651765257f,
-0.923879561784627f, -0.980785296392607f
};
// w_array_imag[i] = sin(-2*M_PI*i/32)
private static final float[] w_array_imag = {
0.000000000000000f, -0.195090327375064f,
-0.382683442461104f, -0.555570246648862f,
-0.707106796640858f, -0.831469627480512f,
-0.923879545057005f, -0.980785287864940f,
-1.000000000000000f, -0.980785270809601f,
-0.923879511601754f, -0.831469578911016f,
-0.707106734823616f, -0.555570173959476f,
-0.382683361692986f, -0.195090241632088f
};
private static final float[] dct4_64_tab = {
0.999924719333649f, 0.998118102550507f,
0.993906974792480f, 0.987301409244537f,
0.978317379951477f, 0.966976463794708f,
0.953306019306183f, 0.937339007854462f,
0.919113874435425f, 0.898674488067627f,
0.876070082187653f, 0.851355195045471f,
0.824589252471924f, 0.795836925506592f,
0.765167236328125f, 0.732654273509979f,
0.698376238346100f, 0.662415742874146f,
0.624859452247620f, 0.585797846317291f,
0.545324981212616f, 0.503538429737091f,
0.460538715124130f, 0.416429549455643f,
0.371317148208618f, 0.325310230255127f,
0.278519600629807f, 0.231058135628700f,
0.183039888739586f, 0.134580686688423f,
0.085797272622585f, 0.036807164549828f,
-1.012196302413940f, -1.059438824653626f,
-1.104129195213318f, -1.146159529685974f,
-1.185428738594055f, -1.221842169761658f,
-1.255311965942383f, -1.285757660865784f,
-1.313105940818787f, -1.337290763854981f,
-1.358253836631775f, -1.375944852828980f,
-1.390321016311646f, -1.401347875595093f,
-1.408998727798462f, -1.413255214691162f,
-1.414107084274292f, -1.411552190780640f,
-1.405596733093262f, -1.396255016326904f,
-1.383549690246582f, -1.367511272430420f,
-1.348178386688232f, -1.325597524642944f,
-1.299823284149170f, -1.270917654037476f,
-1.238950133323669f, -1.203998088836670f,
-1.166145324707031f, -1.125483393669128f,
-1.082109928131104f, -1.036129593849182f,
-0.987653195858002f, -0.936797380447388f,
-0.883684754371643f, -0.828443288803101f,
-0.771206021308899f, -0.712110757827759f,
-0.651300072669983f, -0.588920354843140f,
-0.525121808052063f, -0.460058242082596f,
-0.393886327743530f, -0.326765477657318f,
-0.258857429027557f, -0.190325915813446f,
-0.121335685253143f, -0.052053272724152f,
0.017354607582092f, 0.086720645427704f,
0.155877828598022f, 0.224659323692322f,
0.292899727821350f, 0.360434412956238f,
0.427100926637650f, 0.492738455533981f,
0.557188928127289f, 0.620297133922577f,
0.681910991668701f, 0.741881847381592f,
0.800065577030182f, 0.856321990489960f,
0.910515367984772f, 0.962515234947205f,
1.000000000000000f, 0.998795449733734f,
0.995184719562531f, 0.989176511764526f,
0.980785250663757f, 0.970031261444092f,
0.956940352916718f, 0.941544055938721f,
0.923879504203796f, 0.903989315032959f,
0.881921231746674f, 0.857728600502014f,
0.831469595432281f, 0.803207516670227f,
0.773010432720184f, 0.740951120853424f,
0.707106769084930f, 0.671558916568756f,
0.634393274784088f, 0.595699310302734f,
0.555570185184479f, 0.514102697372437f,
0.471396654844284f, 0.427555114030838f,
0.382683426141739f, 0.336889833211899f,
0.290284633636475f, 0.242980122566223f,
0.195090234279633f, 0.146730497479439f,
0.098017133772373f, 0.049067649990320f,
-1.000000000000000f, -1.047863125801086f,
-1.093201875686646f, -1.135906934738159f,
-1.175875544548035f, -1.213011503219605f,
-1.247225046157837f, -1.278433918952942f,
-1.306562900543213f, -1.331544399261475f,
-1.353317975997925f, -1.371831417083740f,
-1.387039899826050f, -1.398906826972961f,
-1.407403707504273f, -1.412510156631470f,
0f, -1.412510156631470f,
-1.407403707504273f, -1.398906826972961f,
-1.387039899826050f, -1.371831417083740f,
-1.353317975997925f, -1.331544399261475f,
-1.306562900543213f, -1.278433918952942f,
-1.247225046157837f, -1.213011384010315f,
-1.175875544548035f, -1.135907053947449f,
-1.093201875686646f, -1.047863125801086f,
-1.000000000000000f, -0.949727773666382f,
-0.897167563438416f, -0.842446029186249f,
-0.785694956779480f, -0.727051079273224f,
-0.666655659675598f, -0.604654192924500f,
-0.541196048259735f, -0.476434230804443f,
-0.410524487495422f, -0.343625843524933f,
-0.275899350643158f, -0.207508206367493f,
-0.138617098331451f, -0.069392144680023f,
0f, 0.069392263889313f,
0.138617157936096f, 0.207508206367493f,
0.275899469852448f, 0.343625962734222f,
0.410524636507034f, 0.476434201002121f,
0.541196107864380f, 0.604654192924500f,
0.666655719280243f, 0.727051138877869f,
0.785695075988770f, 0.842446029186249f,
0.897167563438416f, 0.949727773666382f
};
private static final int[] bit_rev_tab = {0, 16, 8, 24, 4, 20, 12, 28, 2, 18, 10, 26, 6, 22, 14, 30, 1, 17, 9, 25, 5, 21, 13, 29, 3, 19, 11, 27, 7, 23, 15, 31};
// FFT decimation in frequency
// 4*16*2+16=128+16=144 multiplications
// 6*16*2+10*8+4*16*2=192+80+128=400 additions
private static void fft_dif(float[] Real, float[] Imag) {
float w_real, w_imag; // For faster access
float point1_real, point1_imag, point2_real, point2_imag; // For faster access
int j, i, i2, w_index; // Counters
// First 2 stages of 32 point FFT decimation in frequency
// 4*16*2=64*2=128 multiplications
// 6*16*2=96*2=192 additions
// Stage 1 of 32 point FFT decimation in frequency
for(i = 0; i<16; i++) {
point1_real = Real[i];
point1_imag = Imag[i];
i2 = i+16;
point2_real = Real[i2];
point2_imag = Imag[i2];
w_real = w_array_real[i];
w_imag = w_array_imag[i];
// temp1 = x[i] - x[i2]
point1_real -= point2_real;
point1_imag -= point2_imag;
// x[i1] = x[i] + x[i2]
Real[i] += point2_real;
Imag[i] += point2_imag;
// x[i2] = (x[i] - x[i2]) * w
Real[i2] = ((point1_real*w_real)-(point1_imag*w_imag));
Imag[i2] = ((point1_real*w_imag)+(point1_imag*w_real));
}
// Stage 2 of 32 point FFT decimation in frequency
for(j = 0, w_index = 0; j<8; j++, w_index += 2) {
w_real = w_array_real[w_index];
w_imag = w_array_imag[w_index];
i = j;
point1_real = Real[i];
point1_imag = Imag[i];
i2 = i+8;
point2_real = Real[i2];
point2_imag = Imag[i2];
// temp1 = x[i] - x[i2]
point1_real -= point2_real;
point1_imag -= point2_imag;
// x[i1] = x[i] + x[i2]
Real[i] += point2_real;
Imag[i] += point2_imag;
// x[i2] = (x[i] - x[i2]) * w
Real[i2] = ((point1_real*w_real)-(point1_imag*w_imag));
Imag[i2] = ((point1_real*w_imag)+(point1_imag*w_real));
i = j+16;
point1_real = Real[i];
point1_imag = Imag[i];
i2 = i+8;
point2_real = Real[i2];
point2_imag = Imag[i2];
// temp1 = x[i] - x[i2]
point1_real -= point2_real;
point1_imag -= point2_imag;
// x[i1] = x[i] + x[i2]
Real[i] += point2_real;
Imag[i] += point2_imag;
// x[i2] = (x[i] - x[i2]) * w
Real[i2] = ((point1_real*w_real)-(point1_imag*w_imag));
Imag[i2] = ((point1_real*w_imag)+(point1_imag*w_real));
}
// Stage 3 of 32 point FFT decimation in frequency
// 2*4*2=16 multiplications
// 4*4*2+6*4*2=10*8=80 additions
for(i = 0; i