diff -r e353ca78d28b -r f7e49eff3708 misc/libtremor/mdct.c --- /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(Tsincos_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(Tsincos_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,points>>i,4<<(i+shift)); + } + + for(j=0;j>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>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>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<=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>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>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(iXoX2); + } +} +