mirror of
https://github.com/UberGames/lilium-voyager.git
synced 2024-11-10 14:41:42 +00:00
332 lines
10 KiB
C
332 lines
10 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 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"
|
|
|
|
#ifdef CUSTOM_MODES
|
|
|
|
int clt_mdct_init(mdct_lookup *l,int N, int maxshift)
|
|
{
|
|
int i;
|
|
int N4;
|
|
kiss_twiddle_scalar *trig;
|
|
#if defined(FIXED_POINT)
|
|
int N2=N>>1;
|
|
#endif
|
|
l->n = N;
|
|
N4 = N>>2;
|
|
l->maxshift = maxshift;
|
|
for (i=0;i<=maxshift;i++)
|
|
{
|
|
if (i==0)
|
|
l->kfft[i] = opus_fft_alloc(N>>2>>i, 0, 0);
|
|
else
|
|
l->kfft[i] = opus_fft_alloc_twiddles(N>>2>>i, 0, 0, l->kfft[0]);
|
|
#ifndef ENABLE_TI_DSPLIB55
|
|
if (l->kfft[i]==NULL)
|
|
return 0;
|
|
#endif
|
|
}
|
|
l->trig = trig = (kiss_twiddle_scalar*)opus_alloc((N4+1)*sizeof(kiss_twiddle_scalar));
|
|
if (l->trig==NULL)
|
|
return 0;
|
|
/* We have enough points that sine isn't necessary */
|
|
#if defined(FIXED_POINT)
|
|
for (i=0;i<=N4;i++)
|
|
trig[i] = TRIG_UPSCALE*celt_cos_norm(DIV32(ADD32(SHL32(EXTEND32(i),17),N2),N));
|
|
#else
|
|
for (i=0;i<=N4;i++)
|
|
trig[i] = (kiss_twiddle_scalar)cos(2*PI*i/N);
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
void clt_mdct_clear(mdct_lookup *l)
|
|
{
|
|
int i;
|
|
for (i=0;i<=l->maxshift;i++)
|
|
opus_fft_free(l->kfft[i]);
|
|
opus_free((kiss_twiddle_scalar*)l->trig);
|
|
}
|
|
|
|
#endif /* CUSTOM_MODES */
|
|
|
|
/* Forward MDCT trashes the input array */
|
|
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 i;
|
|
int N, N2, N4;
|
|
kiss_twiddle_scalar sine;
|
|
VARDECL(kiss_fft_scalar, f);
|
|
SAVE_STACK;
|
|
N = l->n;
|
|
N >>= shift;
|
|
N2 = N>>1;
|
|
N4 = N>>2;
|
|
ALLOC(f, N2, kiss_fft_scalar);
|
|
/* sin(x) ~= x here */
|
|
#ifdef FIXED_POINT
|
|
sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N;
|
|
#else
|
|
sine = (kiss_twiddle_scalar)2*PI*(.125f)/N;
|
|
#endif
|
|
|
|
/* 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>>2);i++)
|
|
{
|
|
/* Real part arranged as -d-cR, Imag part arranged as -b+aR*/
|
|
*yp++ = MULT16_32_Q15(*wp2, xp1[N2]) + MULT16_32_Q15(*wp1,*xp2);
|
|
*yp++ = MULT16_32_Q15(*wp1, *xp1) - MULT16_32_Q15(*wp2, xp2[-N2]);
|
|
xp1+=2;
|
|
xp2-=2;
|
|
wp1+=2;
|
|
wp2-=2;
|
|
}
|
|
wp1 = window;
|
|
wp2 = window+overlap-1;
|
|
for(;i<N4-(overlap>>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++ = -MULT16_32_Q15(*wp1, xp1[-N2]) + MULT16_32_Q15(*wp2, *xp2);
|
|
*yp++ = MULT16_32_Q15(*wp2, *xp1) + MULT16_32_Q15(*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 = &l->trig[0];
|
|
for(i=0;i<N4;i++)
|
|
{
|
|
kiss_fft_scalar re, im, yr, yi;
|
|
re = yp[0];
|
|
im = yp[1];
|
|
yr = -S_MUL(re,t[i<<shift]) - S_MUL(im,t[(N4-i)<<shift]);
|
|
yi = -S_MUL(im,t[i<<shift]) + S_MUL(re,t[(N4-i)<<shift]);
|
|
/* works because the cos is nearly one */
|
|
*yp++ = yr + S_MUL(yi,sine);
|
|
*yp++ = yi - S_MUL(yr,sine);
|
|
}
|
|
}
|
|
|
|
/* N/4 complex FFT, down-scales by 4/N */
|
|
opus_fft(l->kfft[shift], (kiss_fft_cpx *)f, (kiss_fft_cpx *)in);
|
|
|
|
/* Post-rotate */
|
|
{
|
|
/* Temp pointers to make it really clear to the compiler what we're doing */
|
|
const kiss_fft_scalar * OPUS_RESTRICT fp = in;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp2 = out+stride*(N2-1);
|
|
const kiss_twiddle_scalar *t = &l->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(fp[1],t[(N4-i)<<shift]) + S_MUL(fp[0],t[i<<shift]);
|
|
yi = S_MUL(fp[0],t[(N4-i)<<shift]) - S_MUL(fp[1],t[i<<shift]);
|
|
/* works because the cos is nearly one */
|
|
*yp1 = yr - S_MUL(yi,sine);
|
|
*yp2 = yi + S_MUL(yr,sine);;
|
|
fp += 2;
|
|
yp1 += 2*stride;
|
|
yp2 -= 2*stride;
|
|
}
|
|
}
|
|
RESTORE_STACK;
|
|
}
|
|
|
|
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 i;
|
|
int N, N2, N4;
|
|
kiss_twiddle_scalar sine;
|
|
VARDECL(kiss_fft_scalar, f);
|
|
VARDECL(kiss_fft_scalar, f2);
|
|
SAVE_STACK;
|
|
N = l->n;
|
|
N >>= shift;
|
|
N2 = N>>1;
|
|
N4 = N>>2;
|
|
ALLOC(f, N2, kiss_fft_scalar);
|
|
ALLOC(f2, N2, kiss_fft_scalar);
|
|
/* sin(x) ~= x here */
|
|
#ifdef FIXED_POINT
|
|
sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N;
|
|
#else
|
|
sine = (kiss_twiddle_scalar)2*PI*(.125f)/N;
|
|
#endif
|
|
|
|
/* 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 = f2;
|
|
const kiss_twiddle_scalar *t = &l->trig[0];
|
|
for(i=0;i<N4;i++)
|
|
{
|
|
kiss_fft_scalar yr, yi;
|
|
yr = -S_MUL(*xp2, t[i<<shift]) + S_MUL(*xp1,t[(N4-i)<<shift]);
|
|
yi = -S_MUL(*xp2, t[(N4-i)<<shift]) - S_MUL(*xp1,t[i<<shift]);
|
|
/* works because the cos is nearly one */
|
|
*yp++ = yr - S_MUL(yi,sine);
|
|
*yp++ = yi + S_MUL(yr,sine);
|
|
xp1+=2*stride;
|
|
xp2-=2*stride;
|
|
}
|
|
}
|
|
|
|
/* Inverse N/4 complex FFT. This one should *not* downscale even in fixed-point */
|
|
opus_ifft(l->kfft[shift], (kiss_fft_cpx *)f2, (kiss_fft_cpx *)f);
|
|
|
|
/* Post-rotate */
|
|
{
|
|
kiss_fft_scalar * OPUS_RESTRICT fp = f;
|
|
const kiss_twiddle_scalar *t = &l->trig[0];
|
|
|
|
for(i=0;i<N4;i++)
|
|
{
|
|
kiss_fft_scalar re, im, yr, yi;
|
|
re = fp[0];
|
|
im = fp[1];
|
|
/* We'd scale up by 2 here, but instead it's done when mixing the windows */
|
|
yr = S_MUL(re,t[i<<shift]) - S_MUL(im,t[(N4-i)<<shift]);
|
|
yi = S_MUL(im,t[i<<shift]) + S_MUL(re,t[(N4-i)<<shift]);
|
|
/* works because the cos is nearly one */
|
|
*fp++ = yr - S_MUL(yi,sine);
|
|
*fp++ = yi + S_MUL(yr,sine);
|
|
}
|
|
}
|
|
/* De-shuffle the components for the middle of the window only */
|
|
{
|
|
const kiss_fft_scalar * OPUS_RESTRICT fp1 = f;
|
|
const kiss_fft_scalar * OPUS_RESTRICT fp2 = f+N2-1;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp = f2;
|
|
for(i = 0; i < N4; i++)
|
|
{
|
|
*yp++ =-*fp1;
|
|
*yp++ = *fp2;
|
|
fp1 += 2;
|
|
fp2 -= 2;
|
|
}
|
|
}
|
|
out -= (N2-overlap)>>1;
|
|
/* Mirror on both sides for TDAC */
|
|
{
|
|
kiss_fft_scalar * OPUS_RESTRICT fp1 = f2+N4-1;
|
|
kiss_fft_scalar * OPUS_RESTRICT xp1 = out+N2-1;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp1 = out+N4-overlap/2;
|
|
const opus_val16 * OPUS_RESTRICT wp1 = window;
|
|
const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1;
|
|
for(i = 0; i< N4-overlap/2; i++)
|
|
{
|
|
*xp1 = *fp1;
|
|
xp1--;
|
|
fp1--;
|
|
}
|
|
for(; i < N4; i++)
|
|
{
|
|
kiss_fft_scalar x1;
|
|
x1 = *fp1--;
|
|
*yp1++ +=-MULT16_32_Q15(*wp1, x1);
|
|
*xp1-- += MULT16_32_Q15(*wp2, x1);
|
|
wp1++;
|
|
wp2--;
|
|
}
|
|
}
|
|
{
|
|
kiss_fft_scalar * OPUS_RESTRICT fp2 = f2+N4;
|
|
kiss_fft_scalar * OPUS_RESTRICT xp2 = out+N2;
|
|
kiss_fft_scalar * OPUS_RESTRICT yp2 = out+N-1-(N4-overlap/2);
|
|
const opus_val16 * OPUS_RESTRICT wp1 = window;
|
|
const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1;
|
|
for(i = 0; i< N4-overlap/2; i++)
|
|
{
|
|
*xp2 = *fp2;
|
|
xp2++;
|
|
fp2++;
|
|
}
|
|
for(; i < N4; i++)
|
|
{
|
|
kiss_fft_scalar x2;
|
|
x2 = *fp2++;
|
|
*yp2-- = MULT16_32_Q15(*wp1, x2);
|
|
*xp2++ = MULT16_32_Q15(*wp2, x2);
|
|
wp1++;
|
|
wp2--;
|
|
}
|
|
}
|
|
RESTORE_STACK;
|
|
}
|