* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
- * by the XIPHOPHORUS Company http://www.xiph.org/ *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
+ * by the Xiph.Org Foundation http://www.xiph.org/ *
* *
********************************************************************
function: normalized modified discrete cosine transform
power of two length transform only [64 <= n ]
- last mod: $Id: mdct.c,v 1.32 2002/10/16 02:43:48 xiphmont Exp $
Original algorithm adapted long ago from _The use of multirate filter
banks for coding of high quality digital audio_, by T. Sporer,
void mdct_init(mdct_lookup *lookup,int n){
int *bitrev=_ogg_malloc(sizeof(*bitrev)*(n/4));
DATA_TYPE *T=_ogg_malloc(sizeof(*T)*(n+n/4));
-
+
int i;
int n2=n>>1;
int log2n=lookup->log2n=rint(log((float)n)/log(2.f));
for(i=0;i<n/8;i++){
int acc=0;
for(j=0;msb>>j;j++)
- if((msb>>j)&i)acc|=1<<j;
+ if((msb>>j)&i)acc|=1<<j;
bitrev[i*2]=((~acc)&mask)-1;
bitrev[i*2+1]=acc;
REG_TYPE r2 = x[4] + x[0];
REG_TYPE r3 = x[4] - x[0];
- x[6] = r0 + r2;
- x[4] = r0 - r2;
-
- r0 = x[5] - x[1];
- r2 = x[7] - x[3];
- x[0] = r1 + r0;
- x[2] = r1 - r0;
-
- r0 = x[5] + x[1];
- r1 = x[7] + x[3];
- x[3] = r2 + r3;
- x[1] = r2 - r3;
- x[7] = r1 + r0;
- x[5] = r1 - r0;
-
+ x[6] = r0 + r2;
+ x[4] = r0 - r2;
+
+ r0 = x[5] - x[1];
+ r2 = x[7] - x[3];
+ x[0] = r1 + r0;
+ x[2] = r1 - r0;
+
+ r0 = x[5] + x[1];
+ r1 = x[7] + x[3];
+ x[3] = r2 + r3;
+ x[1] = r2 - r3;
+ x[7] = r1 + r0;
+ x[5] = r1 - r0;
+
}
/* 16 point butterfly (in place, 4 register) */
x[6] = r0;
x[7] = r1;
- mdct_butterfly_8(x);
- mdct_butterfly_8(x+8);
+ mdct_butterfly_8(x);
+ mdct_butterfly_8(x+8);
}
/* 32 point butterfly (in place, 4 register) */
REG_TYPE r0 = x[30] - x[14];
REG_TYPE r1 = x[31] - x[15];
- x[30] += x[14];
- x[31] += x[15];
- x[14] = r0;
- x[15] = r1;
+ x[30] += x[14];
+ x[31] += x[15];
+ x[14] = r0;
+ x[15] = r1;
- r0 = x[28] - x[12];
- r1 = x[29] - x[13];
- x[28] += x[12];
- x[29] += x[13];
+ r0 = x[28] - x[12];
+ r1 = x[29] - x[13];
+ x[28] += x[12];
+ x[29] += x[13];
x[12] = MULT_NORM( r0 * cPI1_8 - r1 * cPI3_8 );
- x[13] = MULT_NORM( r0 * cPI3_8 + r1 * cPI1_8 );
+ x[13] = MULT_NORM( r0 * cPI3_8 + r1 * cPI1_8 );
r0 = x[26] - x[10];
- r1 = x[27] - x[11];
- x[26] += x[10];
- x[27] += x[11];
- x[10] = MULT_NORM(( r0 - r1 ) * cPI2_8);
- x[11] = MULT_NORM(( r0 + r1 ) * cPI2_8);
-
- r0 = x[24] - x[8];
- r1 = x[25] - x[9];
- x[24] += x[8];
- x[25] += x[9];
- x[8] = MULT_NORM( r0 * cPI3_8 - r1 * cPI1_8 );
- x[9] = MULT_NORM( r1 * cPI3_8 + r0 * cPI1_8 );
-
- r0 = x[22] - x[6];
- r1 = x[7] - x[23];
- x[22] += x[6];
- x[23] += x[7];
- x[6] = r1;
- x[7] = r0;
-
- r0 = x[4] - x[20];
- r1 = x[5] - x[21];
- x[20] += x[4];
- x[21] += x[5];
- x[4] = MULT_NORM( r1 * cPI1_8 + r0 * cPI3_8 );
- x[5] = MULT_NORM( r1 * cPI3_8 - r0 * cPI1_8 );
-
- r0 = x[2] - x[18];
- r1 = x[3] - x[19];
- x[18] += x[2];
- x[19] += x[3];
- x[2] = MULT_NORM(( r1 + r0 ) * cPI2_8);
- x[3] = MULT_NORM(( r1 - r0 ) * cPI2_8);
-
- r0 = x[0] - x[16];
- r1 = x[1] - x[17];
- x[16] += x[0];
- x[17] += x[1];
- x[0] = MULT_NORM( r1 * cPI3_8 + r0 * cPI1_8 );
- x[1] = MULT_NORM( r1 * cPI1_8 - r0 * cPI3_8 );
-
- mdct_butterfly_16(x);
- mdct_butterfly_16(x+16);
+ r1 = x[27] - x[11];
+ x[26] += x[10];
+ x[27] += x[11];
+ x[10] = MULT_NORM(( r0 - r1 ) * cPI2_8);
+ x[11] = MULT_NORM(( r0 + r1 ) * cPI2_8);
+
+ r0 = x[24] - x[8];
+ r1 = x[25] - x[9];
+ x[24] += x[8];
+ x[25] += x[9];
+ x[8] = MULT_NORM( r0 * cPI3_8 - r1 * cPI1_8 );
+ x[9] = MULT_NORM( r1 * cPI3_8 + r0 * cPI1_8 );
+
+ r0 = x[22] - x[6];
+ r1 = x[7] - x[23];
+ x[22] += x[6];
+ x[23] += x[7];
+ x[6] = r1;
+ x[7] = r0;
+
+ r0 = x[4] - x[20];
+ r1 = x[5] - x[21];
+ x[20] += x[4];
+ x[21] += x[5];
+ x[4] = MULT_NORM( r1 * cPI1_8 + r0 * cPI3_8 );
+ x[5] = MULT_NORM( r1 * cPI3_8 - r0 * cPI1_8 );
+
+ r0 = x[2] - x[18];
+ r1 = x[3] - x[19];
+ x[18] += x[2];
+ x[19] += x[3];
+ x[2] = MULT_NORM(( r1 + r0 ) * cPI2_8);
+ x[3] = MULT_NORM(( r1 - r0 ) * cPI2_8);
+
+ r0 = x[0] - x[16];
+ r1 = x[1] - x[17];
+ x[16] += x[0];
+ x[17] += x[1];
+ x[0] = MULT_NORM( r1 * cPI3_8 + r0 * cPI1_8 );
+ x[1] = MULT_NORM( r1 * cPI1_8 - r0 * cPI3_8 );
+
+ mdct_butterfly_16(x);
+ mdct_butterfly_16(x+16);
}
/* N point first stage butterfly (in place, 2 register) */
STIN void mdct_butterfly_first(DATA_TYPE *T,
- DATA_TYPE *x,
- int points){
-
+ DATA_TYPE *x,
+ int points){
+
DATA_TYPE *x1 = x + points - 8;
DATA_TYPE *x2 = x + (points>>1) - 8;
REG_TYPE r0;
REG_TYPE r1;
do{
-
+
r0 = x1[6] - x2[6];
- r1 = x1[7] - x2[7];
- x1[6] += x2[6];
- x1[7] += x2[7];
- x2[6] = MULT_NORM(r1 * T[1] + r0 * T[0]);
- x2[7] = MULT_NORM(r1 * T[0] - r0 * T[1]);
-
- r0 = x1[4] - x2[4];
- r1 = x1[5] - x2[5];
- x1[4] += x2[4];
- x1[5] += x2[5];
- x2[4] = MULT_NORM(r1 * T[5] + r0 * T[4]);
- x2[5] = MULT_NORM(r1 * T[4] - r0 * T[5]);
-
- r0 = x1[2] - x2[2];
- r1 = x1[3] - x2[3];
- x1[2] += x2[2];
- x1[3] += x2[3];
- x2[2] = MULT_NORM(r1 * T[9] + r0 * T[8]);
- x2[3] = MULT_NORM(r1 * T[8] - r0 * T[9]);
-
- r0 = x1[0] - x2[0];
- r1 = x1[1] - x2[1];
- x1[0] += x2[0];
- x1[1] += x2[1];
- x2[0] = MULT_NORM(r1 * T[13] + r0 * T[12]);
- x2[1] = MULT_NORM(r1 * T[12] - r0 * T[13]);
-
+ r1 = x1[7] - x2[7];
+ x1[6] += x2[6];
+ x1[7] += x2[7];
+ x2[6] = MULT_NORM(r1 * T[1] + r0 * T[0]);
+ x2[7] = MULT_NORM(r1 * T[0] - r0 * T[1]);
+
+ r0 = x1[4] - x2[4];
+ r1 = x1[5] - x2[5];
+ x1[4] += x2[4];
+ x1[5] += x2[5];
+ x2[4] = MULT_NORM(r1 * T[5] + r0 * T[4]);
+ x2[5] = MULT_NORM(r1 * T[4] - r0 * T[5]);
+
+ r0 = x1[2] - x2[2];
+ r1 = x1[3] - x2[3];
+ x1[2] += x2[2];
+ x1[3] += x2[3];
+ x2[2] = MULT_NORM(r1 * T[9] + r0 * T[8]);
+ x2[3] = MULT_NORM(r1 * T[8] - r0 * T[9]);
+
+ r0 = x1[0] - x2[0];
+ r1 = x1[1] - x2[1];
+ x1[0] += x2[0];
+ x1[1] += x2[1];
+ x2[0] = MULT_NORM(r1 * T[13] + r0 * T[12]);
+ x2[1] = MULT_NORM(r1 * T[12] - r0 * T[13]);
+
x1-=8;
x2-=8;
T+=16;
/* N/stage point generic N stage butterfly (in place, 2 register) */
STIN void mdct_butterfly_generic(DATA_TYPE *T,
- DATA_TYPE *x,
- int points,
- int trigint){
-
+ DATA_TYPE *x,
+ int points,
+ int trigint){
+
DATA_TYPE *x1 = x + points - 8;
DATA_TYPE *x2 = x + (points>>1) - 8;
REG_TYPE r0;
REG_TYPE r1;
do{
-
+
r0 = x1[6] - x2[6];
- r1 = x1[7] - x2[7];
- x1[6] += x2[6];
- x1[7] += x2[7];
- x2[6] = MULT_NORM(r1 * T[1] + r0 * T[0]);
- x2[7] = MULT_NORM(r1 * T[0] - r0 * T[1]);
-
- T+=trigint;
-
- r0 = x1[4] - x2[4];
- r1 = x1[5] - x2[5];
- x1[4] += x2[4];
- x1[5] += x2[5];
- x2[4] = MULT_NORM(r1 * T[1] + r0 * T[0]);
- x2[5] = MULT_NORM(r1 * T[0] - r0 * T[1]);
-
- T+=trigint;
-
- r0 = x1[2] - x2[2];
- r1 = x1[3] - x2[3];
- x1[2] += x2[2];
- x1[3] += x2[3];
- x2[2] = MULT_NORM(r1 * T[1] + r0 * T[0]);
- x2[3] = MULT_NORM(r1 * T[0] - r0 * T[1]);
-
- T+=trigint;
-
- r0 = x1[0] - x2[0];
- r1 = x1[1] - x2[1];
- x1[0] += x2[0];
- x1[1] += x2[1];
- x2[0] = MULT_NORM(r1 * T[1] + r0 * T[0]);
- x2[1] = MULT_NORM(r1 * T[0] - r0 * T[1]);
-
- T+=trigint;
+ r1 = x1[7] - x2[7];
+ x1[6] += x2[6];
+ x1[7] += x2[7];
+ x2[6] = MULT_NORM(r1 * T[1] + r0 * T[0]);
+ x2[7] = MULT_NORM(r1 * T[0] - r0 * T[1]);
+
+ T+=trigint;
+
+ r0 = x1[4] - x2[4];
+ r1 = x1[5] - x2[5];
+ x1[4] += x2[4];
+ x1[5] += x2[5];
+ x2[4] = MULT_NORM(r1 * T[1] + r0 * T[0]);
+ x2[5] = MULT_NORM(r1 * T[0] - r0 * T[1]);
+
+ T+=trigint;
+
+ r0 = x1[2] - x2[2];
+ r1 = x1[3] - x2[3];
+ x1[2] += x2[2];
+ x1[3] += x2[3];
+ x2[2] = MULT_NORM(r1 * T[1] + r0 * T[0]);
+ x2[3] = MULT_NORM(r1 * T[0] - r0 * T[1]);
+
+ T+=trigint;
+
+ r0 = x1[0] - x2[0];
+ r1 = x1[1] - x2[1];
+ x1[0] += x2[0];
+ x1[1] += x2[1];
+ x2[0] = MULT_NORM(r1 * T[1] + r0 * T[0]);
+ x2[1] = MULT_NORM(r1 * T[0] - r0 * T[1]);
+
+ T+=trigint;
x1-=8;
x2-=8;
}
STIN void mdct_butterflies(mdct_lookup *init,
- DATA_TYPE *x,
- int points){
-
+ DATA_TYPE *x,
+ int points){
+
DATA_TYPE *T=init->trig;
int stages=init->log2n-5;
int i,j;
-
+
if(--stages>0){
mdct_butterfly_first(T,x,points);
}
}
}
-STIN void mdct_bitreverse(mdct_lookup *init,
- DATA_TYPE *x){
+STIN void mdct_bitreverse(mdct_lookup *init,
+ DATA_TYPE *x){
int n = init->n;
int *bit = init->bitrev;
DATA_TYPE *w0 = x;
REG_TYPE r2 = MULT_NORM(r1 * T[0] + r0 * T[1]);
REG_TYPE r3 = MULT_NORM(r1 * T[1] - r0 * T[0]);
- w1 -= 4;
+ w1 -= 4;
r0 = HALVE(x0[1] + x1[1]);
r1 = HALVE(x0[0] - x1[0]);
-
- w0[0] = r0 + r2;
- w1[2] = r0 - r2;
- w0[1] = r1 + r3;
- w1[3] = r3 - r1;
+
+ w0[0] = r0 + r2;
+ w1[2] = r0 - r2;
+ w0[1] = r1 + r3;
+ w1[3] = r3 - r1;
x0 = x+bit[2];
x1 = x+bit[3];
r0 = HALVE(x0[1] + x1[1]);
r1 = HALVE(x0[0] - x1[0]);
-
- w0[2] = r0 + r2;
- w1[0] = r0 - r2;
- w0[3] = r1 + r3;
- w1[1] = r3 - r1;
- T += 4;
- bit += 4;
- w0 += 4;
+ w0[2] = r0 + r2;
+ w1[0] = r0 - r2;
+ w0[3] = r1 + r3;
+ w1[1] = r3 - r1;
+
+ T += 4;
+ bit += 4;
+ w0 += 4;
}while(w0<w1);
}
DATA_TYPE *oX2=out+n2+n4;
DATA_TYPE *iX =out;
T =init->trig+n2;
-
+
do{
oX1-=4;
/* rotate */
/* window + rotate + step 1 */
-
+
REG_TYPE r0;
REG_TYPE r1;
DATA_TYPE *x0=in+n2+n4;
DATA_TYPE *x1=x0+1;
DATA_TYPE *T=init->trig+n2;
-
+
int i=0;
-
+
for(i=0;i<n8;i+=2){
x0 -=4;
T-=2;
r0= x0[2] + x1[0];
- r1= x0[0] + x1[2];
+ r1= x0[0] + x1[2];
w2[i]= MULT_NORM(r1*T[1] + r0*T[0]);
w2[i+1]= MULT_NORM(r1*T[0] - r0*T[1]);
x1 +=4;
}
x1=in+1;
-
+
for(;i<n2-n8;i+=2){
T-=2;
x0 -=4;
r0= x0[2] - x1[0];
- r1= x0[0] - x1[2];
+ r1= x0[0] - x1[2];
w2[i]= MULT_NORM(r1*T[1] + r0*T[0]);
w2[i+1]= MULT_NORM(r1*T[0] - r0*T[1]);
x1 +=4;
}
-
+
x0=in+n;
for(;i<n2;i+=2){
T-=2;
x0 -=4;
r0= -x0[2] - x1[0];
- r1= -x0[0] - x1[2];
+ r1= -x0[0] - x1[2];
w2[i]= MULT_NORM(r1*T[1] + r0*T[0]);
w2[i+1]= MULT_NORM(r1*T[0] - r0*T[1]);
x1 +=4;
T+=2;
}
}
-