ref: 99968abba8f6d488e8ea331b5c9e31aa61212f93
parent: bc13bbaad7deb1c81dfab7a7c0d0bd3bbd9884ef
author: Jean-Marc Valin <[email protected]>
date: Sat Dec 21 09:29:41 EST 2013
Moving bitrev step to forward MDCT too
--- a/celt/kiss_fft.c
+++ b/celt/kiss_fft.c
@@ -600,7 +600,7 @@
#endif /* CUSTOM_MODES */
-void opus_fft(const kiss_fft_state *st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
+void opus_fft_impl(const kiss_fft_state *st,kiss_fft_cpx *fout)
{int m2, m;
int p;
@@ -608,34 +608,10 @@
int fstride[MAXFACTORS];
int i;
int shift;
-#ifdef FIXED_POINT
- /* FIXME: This should eventually just go in the state. */
- opus_val16 scale;
- int scale_shift;
- scale_shift = celt_ilog2(st->nfft);
- if (st->nfft == 1<<scale_shift)
- scale = Q15ONE;
- else
- scale = (1073741824+st->nfft/2)/st->nfft>>(15-scale_shift);
-#endif
/* st->shift can be -1 */
shift = st->shift>0 ? st->shift : 0;
- celt_assert2 (fin != fout, "In-place FFT not supported");
- /* Bit-reverse the input */
- for (i=0;i<st->nfft;i++)
- {- kiss_fft_cpx x = fin[i];
-#ifdef FIXED_POINT
- fout[st->bitrev[i]].r = SHR32(MULT16_32_Q15(scale, x.r), scale_shift);
- fout[st->bitrev[i]].i = SHR32(MULT16_32_Q15(scale, x.i), scale_shift);
-#else
- fout[st->bitrev[i]].r = st->scale*x.r;
- fout[st->bitrev[i]].i = st->scale*x.i;
-#endif
- }
-
fstride[0] = 1;
L=0;
do {@@ -670,6 +646,36 @@
}
m = m2;
}
+}
+
+void opus_fft(const kiss_fft_state *st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
+{+ int i;
+#ifdef FIXED_POINT
+ /* FIXME: This should eventually just go in the state. */
+ opus_val16 scale;
+ int scale_shift;
+ scale_shift = celt_ilog2(st->nfft);
+ if (st->nfft == 1<<scale_shift)
+ scale = Q15ONE;
+ else
+ scale = (1073741824+st->nfft/2)/st->nfft>>(15-scale_shift);
+#endif
+
+ celt_assert2 (fin != fout, "In-place FFT not supported");
+ /* Bit-reverse the input */
+ for (i=0;i<st->nfft;i++)
+ {+ kiss_fft_cpx x = fin[i];
+#ifdef FIXED_POINT
+ fout[st->bitrev[i]].r = SHR32(MULT16_32_Q15(scale, x.r), scale_shift);
+ fout[st->bitrev[i]].i = SHR32(MULT16_32_Q15(scale, x.i), scale_shift);
+#else
+ fout[st->bitrev[i]].r = st->scale*x.r;
+ fout[st->bitrev[i]].i = st->scale*x.i;
+#endif
+ }
+ opus_fft_impl(st, fout);
}
void opus_ifft_impl(const kiss_fft_state *st,kiss_fft_cpx *fout)
--- a/celt/kiss_fft.h
+++ b/celt/kiss_fft.h
@@ -130,6 +130,7 @@
void opus_fft(const kiss_fft_state *cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
void opus_ifft(const kiss_fft_state *cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
+void opus_fft_impl(const kiss_fft_state *st,kiss_fft_cpx *fout);
void opus_ifft_impl(const kiss_fft_state *st,kiss_fft_cpx *fout);
void opus_fft_free(const kiss_fft_state *cfg);
--- a/celt/mdct.c
+++ b/celt/mdct.c
@@ -109,7 +109,18 @@
int N, N2, N4;
kiss_twiddle_scalar sine;
VARDECL(kiss_fft_scalar, f);
- VARDECL(kiss_fft_scalar, f2);
+ VARDECL(kiss_fft_cpx, f2);
+ const kiss_fft_state *st = l->kfft[shift];
+#ifdef FIXED_POINT
+ /* FIXME: This should eventually just go in the state. */
+ opus_val16 scale;
+ int scale_shift;
+ scale_shift = celt_ilog2(st->nfft);
+ if (st->nfft == 1<<scale_shift)
+ scale = Q15ONE;
+ else
+ scale = (1073741824+st->nfft/2)/st->nfft>>(15-scale_shift);
+#endif
SAVE_STACK;
N = l->n;
N >>= shift;
@@ -116,7 +127,7 @@
N2 = N>>1;
N4 = N>>2;
ALLOC(f, N2, kiss_fft_scalar);
- ALLOC(f2, N2, kiss_fft_scalar);
+ ALLOC(f2, N2, kiss_fft_cpx);
/* sin(x) ~= x here */
#ifdef FIXED_POINT
sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N;
@@ -170,24 +181,33 @@
const kiss_twiddle_scalar *t = &l->trig[0];
for(i=0;i<N4;i++)
{+ kiss_fft_cpx yc;
kiss_fft_scalar re, im, yr, yi;
- re = yp[0];
- im = yp[1];
+ re = *yp++;
+ im = *yp++;
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);
+ yc.r = yr + S_MUL(yi,sine);
+ yc.i = yi - S_MUL(yr,sine);
+#ifdef FIXED_POINT
+ yc.r = SHR32(MULT16_32_Q15(scale, yc.r), scale_shift);
+ yc.i = SHR32(MULT16_32_Q15(scale, yc.i), scale_shift);
+#else
+ yc.r *= st->scale;
+ yc.i *= st->scale;
+#endif
+ f2[st->bitrev[i]] = yc;
}
}
/* N/4 complex FFT, down-scales by 4/N */
- opus_fft(l->kfft[shift], (kiss_fft_cpx *)f, (kiss_fft_cpx *)f2);
+ opus_fft_impl(st, f2);
/* Post-rotate */
{/* Temp pointers to make it really clear to the compiler what we're doing */
- const kiss_fft_scalar * OPUS_RESTRICT fp = f2;
+ 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 = &l->trig[0];
@@ -195,12 +215,12 @@
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]);
+ yr = S_MUL(fp->i,t[(N4-i)<<shift]) + S_MUL(fp->r,t[i<<shift]);
+ yi = S_MUL(fp->r,t[(N4-i)<<shift]) - S_MUL(fp->i,t[i<<shift]);
/* works because the cos is nearly one */
*yp1 = yr - S_MUL(yi,sine);
*yp2 = yi + S_MUL(yr,sine);;
- fp += 2;
+ fp++;
yp1 += 2*stride;
yp2 -= 2*stride;
}