590 lines
16 KiB
C
590 lines
16 KiB
C
/************************************************************************
|
|
* Copyright (C) 2002-2009, Xiph.org Foundation
|
|
* Copyright (C) 2010, Robin Watts for Pinknoise Productions Ltd
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following disclaimer
|
|
* in the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* * Neither the names of the Xiph.org Foundation nor Pinknoise
|
|
* Productions Ltd nor the names of its contributors may be used to
|
|
* endorse or promote products derived from this software without
|
|
* specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
************************************************************************
|
|
|
|
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);
|
|
}
|
|
|
|
__attribute__((no_sanitize("signed-integer-overflow")))
|
|
/* 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();
|
|
}
|
|
|
|
__attribute__((no_sanitize("signed-integer-overflow")))
|
|
/* 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);
|
|
}
|
|
|
|
__attribute__((no_sanitize("signed-integer-overflow")))
|
|
/* 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);
|
|
}
|
|
|
|
/* Ignoring overflows as the butterfly dct function expects and uses the overflows */
|
|
__attribute__((no_sanitize("signed-integer-overflow")))
|
|
/* 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);
|
|
}
|
|
|
|
__attribute__((no_sanitize("signed-integer-overflow")))
|
|
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
|
|
|
|
__attribute__((no_sanitize("signed-integer-overflow")))
|
|
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
|
|
}
|
|
}
|
|
|