--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libtremor/mdct.c Sun Apr 24 22:57:57 2011 +0200
@@ -0,0 +1,510 @@
+/********************************************************************
+ * *
+ * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. *
+ * *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
+ * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
+ * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
+ * *
+ * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
+ * 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 1.9 2002/10/16 09:17:39 xiphmont Exp $
+
+ Original algorithm adapted long ago from _The use of multirate filter
+ banks for coding of high quality digital audio_, by T. Sporer,
+ K. Brandenburg and B. Edler, collection of the European Signal
+ Processing Conference (EUSIPCO), Amsterdam, June 1992, Vol.1, pp
+ 211-214
+
+ The below code implements an algorithm that no longer looks much like
+ that presented in the paper, but the basic structure remains if you
+ dig deep enough to see it.
+
+ This module DOES NOT INCLUDE code to generate/apply the window
+ function. Everybody has their own weird favorite including me... I
+ happen to like the properties of y=sin(.5PI*sin^2(x)), but others may
+ vehemently disagree.
+
+ ********************************************************************/
+
+#include "ivorbiscodec.h"
+#include "codebook.h"
+#include "misc.h"
+#include "mdct.h"
+#include "mdct_lookup.h"
+
+
+/* 8 point butterfly (in place) */
+STIN void mdct_butterfly_8(DATA_TYPE *x){
+
+ REG_TYPE r0 = x[4] + x[0];
+ REG_TYPE r1 = x[4] - x[0];
+ REG_TYPE r2 = x[5] + x[1];
+ REG_TYPE r3 = x[5] - x[1];
+ REG_TYPE r4 = x[6] + x[2];
+ REG_TYPE r5 = x[6] - x[2];
+ REG_TYPE r6 = x[7] + x[3];
+ REG_TYPE r7 = x[7] - x[3];
+
+ x[0] = r5 + r3;
+ x[1] = r7 - r1;
+ x[2] = r5 - r3;
+ x[3] = r7 + r1;
+ x[4] = r4 - r0;
+ x[5] = r6 - r2;
+ x[6] = r4 + r0;
+ x[7] = r6 + r2;
+ MB();
+}
+
+/* 16 point butterfly (in place, 4 register) */
+STIN void mdct_butterfly_16(DATA_TYPE *x){
+
+ REG_TYPE r0, r1;
+
+ r0 = x[ 0] - x[ 8]; x[ 8] += x[ 0];
+ r1 = x[ 1] - x[ 9]; x[ 9] += x[ 1];
+ x[ 0] = MULT31((r0 + r1) , cPI2_8);
+ x[ 1] = MULT31((r1 - r0) , cPI2_8);
+ MB();
+
+ r0 = x[10] - x[ 2]; x[10] += x[ 2];
+ r1 = x[ 3] - x[11]; x[11] += x[ 3];
+ x[ 2] = r1; x[ 3] = r0;
+ MB();
+
+ r0 = x[12] - x[ 4]; x[12] += x[ 4];
+ r1 = x[13] - x[ 5]; x[13] += x[ 5];
+ x[ 4] = MULT31((r0 - r1) , cPI2_8);
+ x[ 5] = MULT31((r0 + r1) , cPI2_8);
+ MB();
+
+ r0 = x[14] - x[ 6]; x[14] += x[ 6];
+ r1 = x[15] - x[ 7]; x[15] += x[ 7];
+ x[ 6] = r0; x[ 7] = r1;
+ MB();
+
+ mdct_butterfly_8(x);
+ mdct_butterfly_8(x+8);
+}
+
+/* 32 point butterfly (in place, 4 register) */
+STIN void mdct_butterfly_32(DATA_TYPE *x){
+
+ REG_TYPE r0, r1;
+
+ r0 = x[30] - x[14]; x[30] += x[14];
+ r1 = x[31] - x[15]; x[31] += x[15];
+ x[14] = r0; x[15] = r1;
+ MB();
+
+ r0 = x[28] - x[12]; x[28] += x[12];
+ r1 = x[29] - x[13]; x[29] += x[13];
+ XNPROD31( r0, r1, cPI1_8, cPI3_8, &x[12], &x[13] );
+ MB();
+
+ r0 = x[26] - x[10]; x[26] += x[10];
+ r1 = x[27] - x[11]; x[27] += x[11];
+ x[10] = MULT31((r0 - r1) , cPI2_8);
+ x[11] = MULT31((r0 + r1) , cPI2_8);
+ MB();
+
+ r0 = x[24] - x[ 8]; x[24] += x[ 8];
+ r1 = x[25] - x[ 9]; x[25] += x[ 9];
+ XNPROD31( r0, r1, cPI3_8, cPI1_8, &x[ 8], &x[ 9] );
+ MB();
+
+ r0 = x[22] - x[ 6]; x[22] += x[ 6];
+ r1 = x[ 7] - x[23]; x[23] += x[ 7];
+ x[ 6] = r1; x[ 7] = r0;
+ MB();
+
+ r0 = x[ 4] - x[20]; x[20] += x[ 4];
+ r1 = x[ 5] - x[21]; x[21] += x[ 5];
+ XPROD31 ( r0, r1, cPI3_8, cPI1_8, &x[ 4], &x[ 5] );
+ MB();
+
+ r0 = x[ 2] - x[18]; x[18] += x[ 2];
+ r1 = x[ 3] - x[19]; x[19] += x[ 3];
+ x[ 2] = MULT31((r1 + r0) , cPI2_8);
+ x[ 3] = MULT31((r1 - r0) , cPI2_8);
+ MB();
+
+ r0 = x[ 0] - x[16]; x[16] += x[ 0];
+ r1 = x[ 1] - x[17]; x[17] += x[ 1];
+ XPROD31 ( r0, r1, cPI1_8, cPI3_8, &x[ 0], &x[ 1] );
+ MB();
+
+ mdct_butterfly_16(x);
+ mdct_butterfly_16(x+16);
+}
+
+/* N/stage point generic N stage butterfly (in place, 2 register) */
+STIN void mdct_butterfly_generic(DATA_TYPE *x,int points,int step){
+
+ LOOKUP_T *T = sincos_lookup0;
+ 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]; x1[6] += x2[6];
+ r1 = x2[7] - x1[7]; x1[7] += x2[7];
+ XPROD31( r1, r0, T[0], T[1], &x2[6], &x2[7] ); T+=step;
+
+ r0 = x1[4] - x2[4]; x1[4] += x2[4];
+ r1 = x2[5] - x1[5]; x1[5] += x2[5];
+ XPROD31( r1, r0, T[0], T[1], &x2[4], &x2[5] ); T+=step;
+
+ r0 = x1[2] - x2[2]; x1[2] += x2[2];
+ r1 = x2[3] - x1[3]; x1[3] += x2[3];
+ XPROD31( r1, r0, T[0], T[1], &x2[2], &x2[3] ); T+=step;
+
+ r0 = x1[0] - x2[0]; x1[0] += x2[0];
+ r1 = x2[1] - x1[1]; x1[1] += x2[1];
+ XPROD31( r1, r0, T[0], T[1], &x2[0], &x2[1] ); T+=step;
+
+ x1-=8; x2-=8;
+ }while(T<sincos_lookup0+1024);
+ do{
+ r0 = x1[6] - x2[6]; x1[6] += x2[6];
+ r1 = x1[7] - x2[7]; x1[7] += x2[7];
+ XNPROD31( r0, r1, T[0], T[1], &x2[6], &x2[7] ); T-=step;
+
+ r0 = x1[4] - x2[4]; x1[4] += x2[4];
+ r1 = x1[5] - x2[5]; x1[5] += x2[5];
+ XNPROD31( r0, r1, T[0], T[1], &x2[4], &x2[5] ); T-=step;
+
+ r0 = x1[2] - x2[2]; x1[2] += x2[2];
+ r1 = x1[3] - x2[3]; x1[3] += x2[3];
+ XNPROD31( r0, r1, T[0], T[1], &x2[2], &x2[3] ); T-=step;
+
+ r0 = x1[0] - x2[0]; x1[0] += x2[0];
+ r1 = x1[1] - x2[1]; x1[1] += x2[1];
+ XNPROD31( r0, r1, T[0], T[1], &x2[0], &x2[1] ); T-=step;
+
+ x1-=8; x2-=8;
+ }while(T>sincos_lookup0);
+ do{
+ r0 = x2[6] - x1[6]; x1[6] += x2[6];
+ r1 = x2[7] - x1[7]; x1[7] += x2[7];
+ XPROD31( r0, r1, T[0], T[1], &x2[6], &x2[7] ); T+=step;
+
+ r0 = x2[4] - x1[4]; x1[4] += x2[4];
+ r1 = x2[5] - x1[5]; x1[5] += x2[5];
+ XPROD31( r0, r1, T[0], T[1], &x2[4], &x2[5] ); T+=step;
+
+ r0 = x2[2] - x1[2]; x1[2] += x2[2];
+ r1 = x2[3] - x1[3]; x1[3] += x2[3];
+ XPROD31( r0, r1, T[0], T[1], &x2[2], &x2[3] ); T+=step;
+
+ r0 = x2[0] - x1[0]; x1[0] += x2[0];
+ r1 = x2[1] - x1[1]; x1[1] += x2[1];
+ XPROD31( r0, r1, T[0], T[1], &x2[0], &x2[1] ); T+=step;
+
+ x1-=8; x2-=8;
+ }while(T<sincos_lookup0+1024);
+ do{
+ r0 = x1[6] - x2[6]; x1[6] += x2[6];
+ r1 = x2[7] - x1[7]; x1[7] += x2[7];
+ XNPROD31( r1, r0, T[0], T[1], &x2[6], &x2[7] ); T-=step;
+
+ r0 = x1[4] - x2[4]; x1[4] += x2[4];
+ r1 = x2[5] - x1[5]; x1[5] += x2[5];
+ XNPROD31( r1, r0, T[0], T[1], &x2[4], &x2[5] ); T-=step;
+
+ r0 = x1[2] - x2[2]; x1[2] += x2[2];
+ r1 = x2[3] - x1[3]; x1[3] += x2[3];
+ XNPROD31( r1, r0, T[0], T[1], &x2[2], &x2[3] ); T-=step;
+
+ r0 = x1[0] - x2[0]; x1[0] += x2[0];
+ r1 = x2[1] - x1[1]; x1[1] += x2[1];
+ XNPROD31( r1, r0, T[0], T[1], &x2[0], &x2[1] ); T-=step;
+
+ x1-=8; x2-=8;
+ }while(T>sincos_lookup0);
+}
+
+STIN void mdct_butterflies(DATA_TYPE *x,int points,int shift){
+
+ int stages=8-shift;
+ int i,j;
+
+ for(i=0;--stages>0;i++){
+ for(j=0;j<(1<<i);j++)
+ mdct_butterfly_generic(x+(points>>i)*j,points>>i,4<<(i+shift));
+ }
+
+ for(j=0;j<points;j+=32)
+ mdct_butterfly_32(x+j);
+
+}
+
+static unsigned char bitrev[16]={0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15};
+
+STIN int bitrev12(int x){
+ return bitrev[x>>8]|(bitrev[(x&0x0f0)>>4]<<4)|(((int)bitrev[x&0x00f])<<8);
+}
+
+STIN void mdct_bitreverse(DATA_TYPE *x,int n,int step,int shift){
+
+ int bit = 0;
+ DATA_TYPE *w0 = x;
+ DATA_TYPE *w1 = x = w0+(n>>1);
+ LOOKUP_T *T = (step>=4)?(sincos_lookup0+(step>>1)):sincos_lookup1;
+ LOOKUP_T *Ttop = T+1024;
+ DATA_TYPE r2;
+
+ do{
+ DATA_TYPE r3 = bitrev12(bit++);
+ DATA_TYPE *x0 = x + ((r3 ^ 0xfff)>>shift) -1;
+ DATA_TYPE *x1 = x + (r3>>shift);
+
+ REG_TYPE r0 = x0[0] + x1[0];
+ REG_TYPE r1 = x1[1] - x0[1];
+
+ XPROD32( r0, r1, T[1], T[0], &r2, &r3 ); T+=step;
+
+ w1 -= 4;
+
+ r0 = (x0[1] + x1[1])>>1;
+ r1 = (x0[0] - x1[0])>>1;
+ w0[0] = r0 + r2;
+ w0[1] = r1 + r3;
+ w1[2] = r0 - r2;
+ w1[3] = r3 - r1;
+
+ r3 = bitrev12(bit++);
+ x0 = x + ((r3 ^ 0xfff)>>shift) -1;
+ x1 = x + (r3>>shift);
+
+ r0 = x0[0] + x1[0];
+ r1 = x1[1] - x0[1];
+
+ XPROD32( r0, r1, T[1], T[0], &r2, &r3 ); T+=step;
+
+ r0 = (x0[1] + x1[1])>>1;
+ r1 = (x0[0] - x1[0])>>1;
+ w0[2] = r0 + r2;
+ w0[3] = r1 + r3;
+ w1[0] = r0 - r2;
+ w1[1] = r3 - r1;
+
+ w0 += 4;
+ }while(T<Ttop);
+ do{
+ DATA_TYPE r3 = bitrev12(bit++);
+ DATA_TYPE *x0 = x + ((r3 ^ 0xfff)>>shift) -1;
+ DATA_TYPE *x1 = x + (r3>>shift);
+
+ REG_TYPE r0 = x0[0] + x1[0];
+ REG_TYPE r1 = x1[1] - x0[1];
+
+ T-=step; XPROD32( r0, r1, T[0], T[1], &r2, &r3 );
+
+ w1 -= 4;
+
+ r0 = (x0[1] + x1[1])>>1;
+ r1 = (x0[0] - x1[0])>>1;
+ w0[0] = r0 + r2;
+ w0[1] = r1 + r3;
+ w1[2] = r0 - r2;
+ w1[3] = r3 - r1;
+
+ r3 = bitrev12(bit++);
+ x0 = x + ((r3 ^ 0xfff)>>shift) -1;
+ x1 = x + (r3>>shift);
+
+ r0 = x0[0] + x1[0];
+ r1 = x1[1] - x0[1];
+
+ T-=step; XPROD32( r0, r1, T[0], T[1], &r2, &r3 );
+
+ r0 = (x0[1] + x1[1])>>1;
+ r1 = (x0[0] - x1[0])>>1;
+ w0[2] = r0 + r2;
+ w0[3] = r1 + r3;
+ w1[0] = r0 - r2;
+ w1[1] = r3 - r1;
+
+ w0 += 4;
+ }while(w0<w1);
+}
+
+void mdct_backward(int n, DATA_TYPE *in, DATA_TYPE *out){
+ int n2=n>>1;
+ int n4=n>>2;
+ DATA_TYPE *iX;
+ DATA_TYPE *oX;
+ LOOKUP_T *T;
+ LOOKUP_T *V;
+ int shift;
+ int step;
+
+ for (shift=6;!(n&(1<<shift));shift++);
+ shift=13-shift;
+ step=2<<shift;
+
+ /* rotate */
+
+ iX = in+n2-7;
+ oX = out+n2+n4;
+ T = sincos_lookup0;
+
+ do{
+ oX-=4;
+ XPROD31( iX[4], iX[6], T[0], T[1], &oX[2], &oX[3] ); T+=step;
+ XPROD31( iX[0], iX[2], T[0], T[1], &oX[0], &oX[1] ); T+=step;
+ iX-=8;
+ }while(iX>=in+n4);
+ do{
+ oX-=4;
+ XPROD31( iX[4], iX[6], T[1], T[0], &oX[2], &oX[3] ); T-=step;
+ XPROD31( iX[0], iX[2], T[1], T[0], &oX[0], &oX[1] ); T-=step;
+ iX-=8;
+ }while(iX>=in);
+
+ iX = in+n2-8;
+ oX = out+n2+n4;
+ T = sincos_lookup0;
+
+ do{
+ T+=step; XNPROD31( iX[6], iX[4], T[0], T[1], &oX[0], &oX[1] );
+ T+=step; XNPROD31( iX[2], iX[0], T[0], T[1], &oX[2], &oX[3] );
+ iX-=8;
+ oX+=4;
+ }while(iX>=in+n4);
+ do{
+ T-=step; XNPROD31( iX[6], iX[4], T[1], T[0], &oX[0], &oX[1] );
+ T-=step; XNPROD31( iX[2], iX[0], T[1], T[0], &oX[2], &oX[3] );
+ iX-=8;
+ oX+=4;
+ }while(iX>=in);
+
+ mdct_butterflies(out+n2,n2,shift);
+ mdct_bitreverse(out,n,step,shift);
+
+ /* rotate + window */
+
+ step>>=2;
+ {
+ DATA_TYPE *oX1=out+n2+n4;
+ DATA_TYPE *oX2=out+n2+n4;
+ DATA_TYPE *iX =out;
+
+ switch(step) {
+ default: {
+ T=(step>=4)?(sincos_lookup0+(step>>1)):sincos_lookup1;
+ do{
+ oX1-=4;
+ XPROD31( iX[0], -iX[1], T[0], T[1], &oX1[3], &oX2[0] ); T+=step;
+ XPROD31( iX[2], -iX[3], T[0], T[1], &oX1[2], &oX2[1] ); T+=step;
+ XPROD31( iX[4], -iX[5], T[0], T[1], &oX1[1], &oX2[2] ); T+=step;
+ XPROD31( iX[6], -iX[7], T[0], T[1], &oX1[0], &oX2[3] ); T+=step;
+ oX2+=4;
+ iX+=8;
+ }while(iX<oX1);
+ break;
+ }
+
+ case 1: {
+ /* linear interpolation between table values: offset=0.5, step=1 */
+ REG_TYPE t0,t1,v0,v1;
+ T = sincos_lookup0;
+ V = sincos_lookup1;
+ t0 = (*T++)>>1;
+ t1 = (*T++)>>1;
+ do{
+ oX1-=4;
+
+ t0 += (v0 = (*V++)>>1);
+ t1 += (v1 = (*V++)>>1);
+ XPROD31( iX[0], -iX[1], t0, t1, &oX1[3], &oX2[0] );
+ v0 += (t0 = (*T++)>>1);
+ v1 += (t1 = (*T++)>>1);
+ XPROD31( iX[2], -iX[3], v0, v1, &oX1[2], &oX2[1] );
+ t0 += (v0 = (*V++)>>1);
+ t1 += (v1 = (*V++)>>1);
+ XPROD31( iX[4], -iX[5], t0, t1, &oX1[1], &oX2[2] );
+ v0 += (t0 = (*T++)>>1);
+ v1 += (t1 = (*T++)>>1);
+ XPROD31( iX[6], -iX[7], v0, v1, &oX1[0], &oX2[3] );
+
+ oX2+=4;
+ iX+=8;
+ }while(iX<oX1);
+ break;
+ }
+
+ case 0: {
+ /* linear interpolation between table values: offset=0.25, step=0.5 */
+ REG_TYPE t0,t1,v0,v1,q0,q1;
+ T = sincos_lookup0;
+ V = sincos_lookup1;
+ t0 = *T++;
+ t1 = *T++;
+ do{
+ oX1-=4;
+
+ v0 = *V++;
+ v1 = *V++;
+ t0 += (q0 = (v0-t0)>>2);
+ t1 += (q1 = (v1-t1)>>2);
+ XPROD31( iX[0], -iX[1], t0, t1, &oX1[3], &oX2[0] );
+ t0 = v0-q0;
+ t1 = v1-q1;
+ XPROD31( iX[2], -iX[3], t0, t1, &oX1[2], &oX2[1] );
+
+ t0 = *T++;
+ t1 = *T++;
+ v0 += (q0 = (t0-v0)>>2);
+ v1 += (q1 = (t1-v1)>>2);
+ XPROD31( iX[4], -iX[5], v0, v1, &oX1[1], &oX2[2] );
+ v0 = t0-q0;
+ v1 = t1-q1;
+ XPROD31( iX[6], -iX[7], v0, v1, &oX1[0], &oX2[3] );
+
+ oX2+=4;
+ iX+=8;
+ }while(iX<oX1);
+ break;
+ }
+ }
+
+ iX=out+n2+n4;
+ oX1=out+n4;
+ oX2=oX1;
+
+ do{
+ oX1-=4;
+ iX-=4;
+
+ oX2[0] = -(oX1[3] = iX[3]);
+ oX2[1] = -(oX1[2] = iX[2]);
+ oX2[2] = -(oX1[1] = iX[1]);
+ oX2[3] = -(oX1[0] = iX[0]);
+
+ oX2+=4;
+ }while(oX2<iX);
+
+ iX=out+n2+n4;
+ oX1=out+n2+n4;
+ oX2=out+n2;
+
+ do{
+ oX1-=4;
+ oX1[0]= iX[3];
+ oX1[1]= iX[2];
+ oX1[2]= iX[1];
+ oX1[3]= iX[0];
+ iX+=4;
+ }while(oX1>oX2);
+ }
+}
+