288 lines
9 KiB
C
288 lines
9 KiB
C
/* Copyright (c) 2007-2008 CSIRO
|
|
Copyright (c) 2007-2008 Xiph.Org Foundation
|
|
Written by Jean-Marc Valin */
|
|
/*
|
|
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.
|
|
|
|
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.
|
|
*/
|
|
|
|
/* This is a simple MDCT implementation that uses a N/4 complex FFT
|
|
to do most of the work. It should be relatively straightforward to
|
|
plug in pretty much and FFT here.
|
|
|
|
This replaces the Vorbis FFT (and uses the exact same API), which
|
|
was a bit too messy and that was ending up duplicating code
|
|
(might as well use the same FFT everywhere).
|
|
|
|
The algorithm is similar to (and inspired from) Fabrice Bellard's
|
|
MDCT implementation in FFMPEG, but has differences in signs, ordering
|
|
and scaling in many places.
|
|
*/
|
|
#ifndef __MDCT_MIPSR1_H__
|
|
#define __MDCT_MIPSR1_H__
|
|
|
|
#ifndef SKIP_CONFIG_H
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
#endif
|
|
|
|
#include "mdct.h"
|
|
#include "kiss_fft.h"
|
|
#include "_kiss_fft_guts.h"
|
|
#include <math.h>
|
|
#include "os_support.h"
|
|
#include "mathops.h"
|
|
#include "stack_alloc.h"
|
|
|
|
/* Forward MDCT trashes the input array */
|
|
#define OVERRIDE_clt_mdct_forward
|
|
void clt_mdct_forward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out,
|
|
const opus_val16 *window, int overlap, int shift, int stride, int arch)
|
|
{
|
|
int i;
|
|
int N, N2, N4;
|
|
VARDECL(kiss_fft_scalar, f);
|
|
VARDECL(kiss_fft_cpx, f2);
|
|
const kiss_fft_state *st = l->kfft[shift];
|
|
const kiss_twiddle_scalar *trig;
|
|
opus_val16 scale;
|
|
#ifdef FIXED_POINT
|
|
/* Allows us to scale with MULT16_32_Q16(), which is faster than
|
|
MULT16_32_Q15() on ARM. */
|
|
int scale_shift = st->scale_shift-1;
|
|
#endif
|
|
|
|
(void)arch;
|
|
|
|
SAVE_STACK;
|
|
scale = st->scale;
|
|
|
|
N = l->n;
|
|
trig = l->trig;
|
|
for (i=0;i<shift;i++)
|
|
{
|
|
N >>= 1;
|
|
trig += N;
|
|
}
|
|
N2 = N>>1;
|
|
N4 = N>>2;
|
|
|
|
ALLOC(f, N2, kiss_fft_scalar);
|
|
ALLOC(f2, N4, kiss_fft_cpx);
|
|
|
|
/* Consider the input to be composed of four blocks: [a, b, c, d] */
|
|
/* Window, shuffle, fold */
|
|
{
|
|
/* Temp pointers to make it really clear to the compiler what we're doing */
|
|
const kiss_fft_scalar * OPUS_RESTRICT xp1 = in+(overlap>>1);
|
|
const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+N2-1+(overlap>>1);
|
|
kiss_fft_scalar * OPUS_RESTRICT yp = f;
|
|
const opus_val16 * OPUS_RESTRICT wp1 = window+(overlap>>1);
|
|
const opus_val16 * OPUS_RESTRICT wp2 = window+(overlap>>1)-1;
|
|
for(i=0;i<((overlap+3)>>2);i++)
|
|
{
|
|
/* Real part arranged as -d-cR, Imag part arranged as -b+aR*/
|
|
*yp++ = S_MUL_ADD(*wp2, xp1[N2],*wp1,*xp2);
|
|
*yp++ = S_MUL_SUB(*wp1, *xp1,*wp2, xp2[-N2]);
|
|
xp1+=2;
|
|
xp2-=2;
|
|
wp1+=2;
|
|
wp2-=2;
|
|
}
|
|
wp1 = window;
|
|
wp2 = window+overlap-1;
|
|
for(;i<N4-((overlap+3)>>2);i++)
|
|
{
|
|
/* Real part arranged as a-bR, Imag part arranged as -c-dR */
|
|
*yp++ = *xp2;
|
|
*yp++ = *xp1;
|
|
xp1+=2;
|
|
xp2-=2;
|
|
}
|
|
for(;i<N4;i++)
|
|
{
|
|
/* Real part arranged as a-bR, Imag part arranged as -c-dR */
|
|
*yp++ = S_MUL_SUB(*wp2, *xp2, *wp1, xp1[-N2]);
|
|
*yp++ = S_MUL_ADD(*wp2, *xp1, *wp1, xp2[N2]);
|
|
xp1+=2;
|
|
xp2-=2;
|
|
wp1+=2;
|
|
wp2-=2;
|
|
}
|
|
}
|
|
/* Pre-rotation */
|
|
{
|
|
kiss_fft_scalar * OPUS_RESTRICT yp = f;
|
|
const kiss_twiddle_scalar *t = &trig[0];
|
|
for(i=0;i<N4;i++)
|
|
{
|
|
kiss_fft_cpx yc;
|
|
kiss_twiddle_scalar t0, t1;
|
|
kiss_fft_scalar re, im, yr, yi;
|
|
t0 = t[i];
|
|
t1 = t[N4+i];
|
|
re = *yp++;
|
|
im = *yp++;
|
|
|
|
yr = S_MUL_SUB(re,t0,im,t1);
|
|
yi = S_MUL_ADD(im,t0,re,t1);
|
|
|
|
yc.r = yr;
|
|
yc.i = yi;
|
|
yc.r = PSHR32(MULT16_32_Q16(scale, yc.r), scale_shift);
|
|
yc.i = PSHR32(MULT16_32_Q16(scale, yc.i), scale_shift);
|
|
f2[st->bitrev[i]] = yc;
|
|
}
|
|
}
|
|
|
|
/* N/4 complex FFT, does not downscale anymore */
|
|
opus_fft_impl(st, f2);
|
|
|
|
/* Post-rotate */
|
|
{
|
|
/* Temp pointers to make it really clear to the compiler what we're doing */
|
|
const kiss_fft_cpx * OPUS_RESTRICT fp = f2;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp2 = out+stride*(N2-1);
|
|
const kiss_twiddle_scalar *t = &trig[0];
|
|
/* Temp pointers to make it really clear to the compiler what we're doing */
|
|
for(i=0;i<N4;i++)
|
|
{
|
|
kiss_fft_scalar yr, yi;
|
|
yr = S_MUL_SUB(fp->i,t[N4+i] , fp->r,t[i]);
|
|
yi = S_MUL_ADD(fp->r,t[N4+i] ,fp->i,t[i]);
|
|
*yp1 = yr;
|
|
*yp2 = yi;
|
|
fp++;
|
|
yp1 += 2*stride;
|
|
yp2 -= 2*stride;
|
|
}
|
|
}
|
|
RESTORE_STACK;
|
|
}
|
|
|
|
#define OVERRIDE_clt_mdct_backward
|
|
void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out,
|
|
const opus_val16 * OPUS_RESTRICT window, int overlap, int shift, int stride, int arch)
|
|
{
|
|
int i;
|
|
int N, N2, N4;
|
|
const kiss_twiddle_scalar *trig;
|
|
|
|
(void)arch;
|
|
|
|
N = l->n;
|
|
trig = l->trig;
|
|
for (i=0;i<shift;i++)
|
|
{
|
|
N >>= 1;
|
|
trig += N;
|
|
}
|
|
N2 = N>>1;
|
|
N4 = N>>2;
|
|
|
|
/* Pre-rotate */
|
|
{
|
|
/* Temp pointers to make it really clear to the compiler what we're doing */
|
|
const kiss_fft_scalar * OPUS_RESTRICT xp1 = in;
|
|
const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+stride*(N2-1);
|
|
kiss_fft_scalar * OPUS_RESTRICT yp = out+(overlap>>1);
|
|
const kiss_twiddle_scalar * OPUS_RESTRICT t = &trig[0];
|
|
const opus_int16 * OPUS_RESTRICT bitrev = l->kfft[shift]->bitrev;
|
|
for(i=0;i<N4;i++)
|
|
{
|
|
int rev;
|
|
kiss_fft_scalar yr, yi;
|
|
rev = *bitrev++;
|
|
yr = S_MUL_ADD(*xp2, t[i] , *xp1, t[N4+i]);
|
|
yi = S_MUL_SUB(*xp1, t[i] , *xp2, t[N4+i]);
|
|
/* We swap real and imag because we use an FFT instead of an IFFT. */
|
|
yp[2*rev+1] = yr;
|
|
yp[2*rev] = yi;
|
|
/* Storing the pre-rotation directly in the bitrev order. */
|
|
xp1+=2*stride;
|
|
xp2-=2*stride;
|
|
}
|
|
}
|
|
|
|
opus_fft_impl(l->kfft[shift], (kiss_fft_cpx*)(out+(overlap>>1)));
|
|
|
|
/* Post-rotate and de-shuffle from both ends of the buffer at once to make
|
|
it in-place. */
|
|
{
|
|
kiss_fft_scalar * OPUS_RESTRICT yp0 = out+(overlap>>1);
|
|
kiss_fft_scalar * OPUS_RESTRICT yp1 = out+(overlap>>1)+N2-2;
|
|
const kiss_twiddle_scalar *t = &trig[0];
|
|
/* Loop to (N4+1)>>1 to handle odd N4. When N4 is odd, the
|
|
middle pair will be computed twice. */
|
|
for(i=0;i<(N4+1)>>1;i++)
|
|
{
|
|
kiss_fft_scalar re, im, yr, yi;
|
|
kiss_twiddle_scalar t0, t1;
|
|
/* We swap real and imag because we're using an FFT instead of an IFFT. */
|
|
re = yp0[1];
|
|
im = yp0[0];
|
|
t0 = t[i];
|
|
t1 = t[N4+i];
|
|
/* We'd scale up by 2 here, but instead it's done when mixing the windows */
|
|
yr = S_MUL_ADD(re,t0 , im,t1);
|
|
yi = S_MUL_SUB(re,t1 , im,t0);
|
|
/* We swap real and imag because we're using an FFT instead of an IFFT. */
|
|
re = yp1[1];
|
|
im = yp1[0];
|
|
yp0[0] = yr;
|
|
yp1[1] = yi;
|
|
|
|
t0 = t[(N4-i-1)];
|
|
t1 = t[(N2-i-1)];
|
|
/* We'd scale up by 2 here, but instead it's done when mixing the windows */
|
|
yr = S_MUL_ADD(re,t0,im,t1);
|
|
yi = S_MUL_SUB(re,t1,im,t0);
|
|
yp1[0] = yr;
|
|
yp0[1] = yi;
|
|
yp0 += 2;
|
|
yp1 -= 2;
|
|
}
|
|
}
|
|
|
|
/* Mirror on both sides for TDAC */
|
|
{
|
|
kiss_fft_scalar * OPUS_RESTRICT xp1 = out+overlap-1;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
|
|
const opus_val16 * OPUS_RESTRICT wp1 = window;
|
|
const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1;
|
|
|
|
for(i = 0; i < overlap/2; i++)
|
|
{
|
|
kiss_fft_scalar x1, x2;
|
|
x1 = *xp1;
|
|
x2 = *yp1;
|
|
*yp1++ = MULT16_32_Q15(*wp2, x2) - MULT16_32_Q15(*wp1, x1);
|
|
*xp1-- = MULT16_32_Q15(*wp1, x2) + MULT16_32_Q15(*wp2, x1);
|
|
wp1++;
|
|
wp2--;
|
|
}
|
|
}
|
|
}
|
|
#endif /* __MDCT_MIPSR1_H__ */
|