diff options
Diffstat (limited to 'Tremolo/mdct.c')
-rw-r--r-- | Tremolo/mdct.c | 562 |
1 files changed, 562 insertions, 0 deletions
diff --git a/Tremolo/mdct.c b/Tremolo/mdct.c new file mode 100644 index 0000000..450819b --- /dev/null +++ b/Tremolo/mdct.c @@ -0,0 +1,562 @@ +/******************************************************************** + * * + * 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 1994-2003 * + * 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 1.9.6.5 2003/04/29 04:03:27 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 "os.h" +#include "misc.h" +#include "mdct.h" +#include "mdct_lookup.h" + +#include <stdio.h> + +#if defined(ONLY_C) +STIN void presymmetry(DATA_TYPE *in,int n2,int step){ + DATA_TYPE *aX; + DATA_TYPE *bX; + LOOKUP_T *T; + int n4=n2>>1; + + aX = in+n2-3; + T = sincos_lookup0; + + do{ + REG_TYPE s0= aX[0]; + REG_TYPE s2= aX[2]; + XPROD31( s0, s2, T[0], T[1], &aX[0], &aX[2] ); T+=step; + aX-=4; + }while(aX>=in+n4); + do{ + REG_TYPE s0= aX[0]; + REG_TYPE s2= aX[2]; + XPROD31( s0, s2, T[1], T[0], &aX[0], &aX[2] ); T-=step; + aX-=4; + }while(aX>=in); + + aX = in+n2-4; + bX = in; + T = sincos_lookup0; + do{ + REG_TYPE ri0= aX[0]; + REG_TYPE ri2= aX[2]; + REG_TYPE ro0= bX[0]; + REG_TYPE ro2= bX[2]; + + XNPROD31( ro2, ro0, T[1], T[0], &aX[0], &aX[2] ); T+=step; + XNPROD31( ri2, ri0, T[0], T[1], &bX[0], &bX[2] ); + + aX-=4; + bX+=4; + }while(aX>=bX); +} + +/* 8 point butterfly (in place) */ +STIN void mdct_butterfly_8(DATA_TYPE *x){ + + REG_TYPE s0 = x[0] + x[1]; + REG_TYPE s1 = x[0] - x[1]; + REG_TYPE s2 = x[2] + x[3]; + REG_TYPE s3 = x[2] - x[3]; + REG_TYPE s4 = x[4] + x[5]; + REG_TYPE s5 = x[4] - x[5]; + REG_TYPE s6 = x[6] + x[7]; + REG_TYPE s7 = x[6] - x[7]; + + x[0] = s5 + s3; + x[1] = s7 - s1; + x[2] = s5 - s3; + x[3] = s7 + s1; + x[4] = s4 - s0; + x[5] = s6 - s2; + x[6] = s4 + s0; + x[7] = s6 + s2; + MB(); +} + +/* 16 point butterfly (in place, 4 register) */ +STIN void mdct_butterfly_16(DATA_TYPE *x){ + + REG_TYPE s0, s1, s2, s3; + + s0 = x[ 8] - x[ 9]; x[ 8] += x[ 9]; + s1 = x[10] - x[11]; x[10] += x[11]; + s2 = x[ 1] - x[ 0]; x[ 9] = x[ 1] + x[0]; + s3 = x[ 3] - x[ 2]; x[11] = x[ 3] + x[2]; + x[ 0] = MULT31((s0 - s1) , cPI2_8); + x[ 1] = MULT31((s2 + s3) , cPI2_8); + x[ 2] = MULT31((s0 + s1) , cPI2_8); + x[ 3] = MULT31((s3 - s2) , cPI2_8); + MB(); + + s2 = x[12] - x[13]; x[12] += x[13]; + s3 = x[14] - x[15]; x[14] += x[15]; + s0 = x[ 4] - x[ 5]; x[13] = x[ 5] + x[ 4]; + s1 = x[ 7] - x[ 6]; x[15] = x[ 7] + x[ 6]; + x[ 4] = s2; x[ 5] = s1; + x[ 6] = s3; x[ 7] = s0; + 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 s0, s1, s2, s3; + + s0 = x[16] - x[17]; x[16] += x[17]; + s1 = x[18] - x[19]; x[18] += x[19]; + s2 = x[ 1] - x[ 0]; x[17] = x[ 1] + x[ 0]; + s3 = x[ 3] - x[ 2]; x[19] = x[ 3] + x[ 2]; + XNPROD31( s0, s1, cPI3_8, cPI1_8, &x[ 0], &x[ 2] ); + XPROD31 ( s2, s3, cPI1_8, cPI3_8, &x[ 1], &x[ 3] ); + MB(); + + s0 = x[20] - x[21]; x[20] += x[21]; + s1 = x[22] - x[23]; x[22] += x[23]; + s2 = x[ 5] - x[ 4]; x[21] = x[ 5] + x[ 4]; + s3 = x[ 7] - x[ 6]; x[23] = x[ 7] + x[ 6]; + x[ 4] = MULT31((s0 - s1) , cPI2_8); + x[ 5] = MULT31((s3 + s2) , cPI2_8); + x[ 6] = MULT31((s0 + s1) , cPI2_8); + x[ 7] = MULT31((s3 - s2) , cPI2_8); + MB(); + + s0 = x[24] - x[25]; x[24] += x[25]; + s1 = x[26] - x[27]; x[26] += x[27]; + s2 = x[ 9] - x[ 8]; x[25] = x[ 9] + x[ 8]; + s3 = x[11] - x[10]; x[27] = x[11] + x[10]; + XNPROD31( s0, s1, cPI1_8, cPI3_8, &x[ 8], &x[10] ); + XPROD31 ( s2, s3, cPI3_8, cPI1_8, &x[ 9], &x[11] ); + MB(); + + s0 = x[28] - x[29]; x[28] += x[29]; + s1 = x[30] - x[31]; x[30] += x[31]; + s2 = x[12] - x[13]; x[29] = x[13] + x[12]; + s3 = x[15] - x[14]; x[31] = x[15] + x[14]; + x[12] = s0; x[13] = s3; + x[14] = s1; x[15] = s2; + 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 - 4; + DATA_TYPE *x2 = x + (points>>1) - 4; + REG_TYPE s0, s1, s2, s3; + + do{ + s0 = x1[0] - x1[1]; x1[0] += x1[1]; + s1 = x1[3] - x1[2]; x1[2] += x1[3]; + s2 = x2[1] - x2[0]; x1[1] = x2[1] + x2[0]; + s3 = x2[3] - x2[2]; x1[3] = x2[3] + x2[2]; + XPROD31( s1, s0, T[0], T[1], &x2[0], &x2[2] ); + XPROD31( s2, s3, T[0], T[1], &x2[1], &x2[3] ); T+=step; + x1-=4; + x2-=4; + }while(T<sincos_lookup0+1024); + x1 = x + (points>>1) + (points>>2) - 4; + x2 = x + (points>>2) - 4; + T = sincos_lookup0+1024; + do{ + s0 = x1[0] - x1[1]; x1[0] += x1[1]; + s1 = x1[2] - x1[3]; x1[2] += x1[3]; + s2 = x2[0] - x2[1]; x1[1] = x2[1] + x2[0]; + s3 = x2[3] - x2[2]; x1[3] = x2[3] + x2[2]; + XNPROD31( s0, s1, T[0], T[1], &x2[0], &x2[2] ); + XNPROD31( s3, s2, T[0], T[1], &x2[1], &x2[3] ); T-=step; + x1-=4; + x2-=4; + }while(T>sincos_lookup0); +} + +STIN void mdct_butterflies(DATA_TYPE *x,int points,int shift){ + + int stages=7-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 shift){ + int bit = 0; + DATA_TYPE *w = x+(n>>1); + + do{ + DATA_TYPE b = bitrev12(bit++); + DATA_TYPE *xx = x + (b>>shift); + REG_TYPE r; + + w -= 2; + + if(w>xx){ + + r = xx[0]; + xx[0] = w[0]; + w[0] = r; + + r = xx[1]; + xx[1] = w[1]; + w[1] = r; + } + }while(w>x); +} + +STIN void mdct_step7(DATA_TYPE *x,int n,int step){ + DATA_TYPE *w0 = x; + DATA_TYPE *w1 = x+(n>>1); + LOOKUP_T *T = (step>=4)?(sincos_lookup0+(step>>1)):sincos_lookup1; + LOOKUP_T *Ttop = T+1024; + REG_TYPE s0, s1, s2, s3; + + do{ + w1 -= 2; + + s0 = w0[0] + w1[0]; + s1 = w1[1] - w0[1]; + s2 = MULT32(s0, T[1]) + MULT32(s1, T[0]); + s3 = MULT32(s1, T[1]) - MULT32(s0, T[0]); + T+=step; + + s0 = (w0[1] + w1[1])>>1; + s1 = (w0[0] - w1[0])>>1; + w0[0] = s0 + s2; + w0[1] = s1 + s3; + w1[0] = s0 - s2; + w1[1] = s3 - s1; + + w0 += 2; + }while(T<Ttop); + do{ + w1 -= 2; + + s0 = w0[0] + w1[0]; + s1 = w1[1] - w0[1]; + T-=step; + s2 = MULT32(s0, T[0]) + MULT32(s1, T[1]); + s3 = MULT32(s1, T[0]) - MULT32(s0, T[1]); + + s0 = (w0[1] + w1[1])>>1; + s1 = (w0[0] - w1[0])>>1; + w0[0] = s0 + s2; + w0[1] = s1 + s3; + w1[0] = s0 - s2; + w1[1] = s3 - s1; + + w0 += 2; + }while(w0<w1); +} +#endif + +STIN void mdct_step8(DATA_TYPE *x, int n, int step){ + LOOKUP_T *T; + LOOKUP_T *V; + DATA_TYPE *iX =x+(n>>1); + + switch(step) { +#if defined(ONLY_C) + default: + T=(step>=4)?(sincos_lookup0+(step>>1)):sincos_lookup1; + do{ + REG_TYPE s0 = x[0]; + REG_TYPE s1 = -x[1]; + XPROD31( s0, s1, T[0], T[1], x, x+1); T+=step; + x +=2; + }while(x<iX); + break; +#endif + + case 1: + { + /* linear interpolation between table values: offset=0.5, step=1 */ + REG_TYPE t0,t1,v0,v1,s0,s1; + T = sincos_lookup0; + V = sincos_lookup1; + t0 = (*T++)>>1; + t1 = (*T++)>>1; + do{ + s0 = x[0]; + s1 = -x[1]; + t0 += (v0 = (*V++)>>1); + t1 += (v1 = (*V++)>>1); + XPROD31( s0, s1, t0, t1, x, x+1 ); + + s0 = x[2]; + s1 = -x[3]; + v0 += (t0 = (*T++)>>1); + v1 += (t1 = (*T++)>>1); + XPROD31( s0, s1, v0, v1, x+2, x+3 ); + + x += 4; + }while(x<iX); + break; + } + + case 0: + { + /* linear interpolation between table values: offset=0.25, step=0.5 */ + REG_TYPE t0,t1,v0,v1,q0,q1,s0,s1; + T = sincos_lookup0; + V = sincos_lookup1; + t0 = *T++; + t1 = *T++; + do{ + + + v0 = *V++; + v1 = *V++; + t0 += (q0 = (v0-t0)>>2); + t1 += (q1 = (v1-t1)>>2); + s0 = x[0]; + s1 = -x[1]; + XPROD31( s0, s1, t0, t1, x, x+1 ); + t0 = v0-q0; + t1 = v1-q1; + s0 = x[2]; + s1 = -x[3]; + XPROD31( s0, s1, t0, t1, x+2, x+3 ); + + t0 = *T++; + t1 = *T++; + v0 += (q0 = (t0-v0)>>2); + v1 += (q1 = (t1-v1)>>2); + s0 = x[4]; + s1 = -x[5]; + XPROD31( s0, s1, v0, v1, x+4, x+5 ); + v0 = t0-q0; + v1 = t1-q1; + s0 = x[6]; + s1 = -x[7]; + XPROD31( s0, s1, v0, v1, x+5, x+6 ); + + x+=8; + }while(x<iX); + break; + } + } +} + +extern int mdct_backwardARM(int n, DATA_TYPE *in); + +/* partial; doesn't perform last-step deinterleave/unrolling. That + can be done more efficiently during pcm output */ +void mdct_backward(int n, DATA_TYPE *in){ + int step; + +#if defined(ONLY_C) + int shift; + + for (shift=4;!(n&(1<<shift));shift++); + shift=13-shift; + step=2<<shift; + + presymmetry(in,n>>1,step); + mdct_butterflies(in,n>>1,shift); + mdct_bitreverse(in,n,shift); + mdct_step7(in,n,step); + mdct_step8(in,n,step>>2); +#else + step = mdct_backwardARM(n, in); + if (step < 1) + mdct_step8(in,n,step); +#endif +} + +#if defined(ONLY_C) +void mdct_shift_right(int n, DATA_TYPE *in, DATA_TYPE *right){ + int i; + n>>=2; + in+=1; + + for(i=0;i<n;i++) + right[i]=in[i<<1]; +} +#endif + +extern ogg_int16_t *mdct_unroll_prelap(ogg_int16_t *out, + DATA_TYPE *post, + DATA_TYPE *l, + int step); +extern ogg_int16_t *mdct_unroll_part2(ogg_int16_t *out, + DATA_TYPE *post, + DATA_TYPE *l, + DATA_TYPE *r, + int step, + LOOKUP_T *wL, + LOOKUP_T *wR); +extern ogg_int16_t *mdct_unroll_part3(ogg_int16_t *out, + DATA_TYPE *post, + DATA_TYPE *l, + DATA_TYPE *r, + int step, + LOOKUP_T *wL, + LOOKUP_T *wR); +extern ogg_int16_t *mdct_unroll_postlap(ogg_int16_t *out, + DATA_TYPE *post, + DATA_TYPE *l, + int step); + +void mdct_unroll_lap(int n0,int n1, + int lW,int W, + DATA_TYPE *in, + DATA_TYPE *right, + LOOKUP_T *w0, + LOOKUP_T *w1, + ogg_int16_t *out, + int step, + int start, /* samples, this frame */ + int end /* samples, this frame */){ + + DATA_TYPE *l=in+(W&&lW ? n1>>1 : n0>>1); + DATA_TYPE *r=right+(lW ? n1>>2 : n0>>2); + DATA_TYPE *post; + LOOKUP_T *wR=(W && lW ? w1+(n1>>1) : w0+(n0>>1)); + LOOKUP_T *wL=(W && lW ? w1 : w0 ); + + int preLap=(lW && !W ? (n1>>2)-(n0>>2) : 0 ); + int halfLap=(lW && W ? (n1>>2) : (n0>>2) ); + int postLap=(!lW && W ? (n1>>2)-(n0>>2) : 0 ); + int n,off; + + /* preceeding direct-copy lapping from previous frame, if any */ + if(preLap){ + n = (end<preLap?end:preLap); + off = (start<preLap?start:preLap); + post = r-n; + r -= off; + start -= off; + end -= n; +#if defined(ONLY_C) + while(r>post){ + *out = CLIP_TO_15((*--r)>>9); + out+=step; + } +#else + out = mdct_unroll_prelap(out,post,r,step); + n -= off; + if (n < 0) + n = 0; + r -= n; +#endif + } + + /* cross-lap; two halves due to wrap-around */ + n = (end<halfLap?end:halfLap); + off = (start<halfLap?start:halfLap); + post = r-n; + r -= off; + l -= off*2; + start -= off; + wR -= off; + wL += off; + end -= n; +#if defined(ONLY_C) + while(r>post){ + l-=2; + *out = CLIP_TO_15((MULT31(*--r,*--wR) + MULT31(*l,*wL++))>>9); + out+=step; + } +#else + out = mdct_unroll_part2(out, post, l, r, step, wL, wR); + n -= off; + if (n < 0) + n = 0; + l -= 2*n; + r -= n; + wR -= n; + wL += n; +#endif + + n = (end<halfLap?end:halfLap); + off = (start<halfLap?start:halfLap); + post = r+n; + r += off; + l += off*2; + start -= off; + end -= n; + wR -= off; + wL += off; +#if defined(ONLY_C) + while(r<post){ + *out = CLIP_TO_15((MULT31(*r++,*--wR) - MULT31(*l,*wL++))>>9); + out+=step; + l+=2; + } +#else + out = mdct_unroll_part3(out, post, l, r, step, wL, wR); + n -= off; + if (n < 0) + n = 0; + l += 2*n; + r += n; + wR -= n; + wL += n; +#endif + + /* preceeding direct-copy lapping from previous frame, if any */ + if(postLap){ + n = (end<postLap?end:postLap); + off = (start<postLap?start:postLap); + post = l+n*2; + l += off*2; +#if defined(ONLY_C) + while(l<post){ + *out = CLIP_TO_15((-*l)>>9); + out+=step; + l+=2; + } +#else + out = mdct_unroll_postlap(out,post,l,step); +#endif + } +} + |