* Copyright (c) 2002 Fabrice Bellard
* Partly based on libdjbfft by D. J. Bernstein
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file libavcodec/fft.c
+ * @file
* FFT/IFFT transforms.
*/
-#include "dsputil.h"
+#include <stdlib.h>
+#include <string.h>
+#include "libavutil/mathematics.h"
+#include "fft.h"
+#include "fft-internal.h"
/* cos(2*pi*x/n) for 0<=x<=n/4, followed by its reverse */
-DECLARE_ALIGNED_16(FFTSample, ff_cos_16[8]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_32[16]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_64[32]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_128[64]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_256[128]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_512[256]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_1024[512]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_2048[1024]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_4096[2048]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_8192[4096]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_16384[8192]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_32768[16384]);
-DECLARE_ALIGNED_16(FFTSample, ff_cos_65536[32768]);
-FFTSample * const ff_cos_tabs[] = {
- ff_cos_16, ff_cos_32, ff_cos_64, ff_cos_128, ff_cos_256, ff_cos_512, ff_cos_1024,
- ff_cos_2048, ff_cos_4096, ff_cos_8192, ff_cos_16384, ff_cos_32768, ff_cos_65536,
+#if !CONFIG_HARDCODED_TABLES
+COSTABLE(16);
+COSTABLE(32);
+COSTABLE(64);
+COSTABLE(128);
+COSTABLE(256);
+COSTABLE(512);
+COSTABLE(1024);
+COSTABLE(2048);
+COSTABLE(4096);
+COSTABLE(8192);
+COSTABLE(16384);
+COSTABLE(32768);
+COSTABLE(65536);
+#endif
+COSTABLE_CONST FFTSample * const FFT_NAME(ff_cos_tabs)[] = {
+ NULL, NULL, NULL, NULL,
+ FFT_NAME(ff_cos_16),
+ FFT_NAME(ff_cos_32),
+ FFT_NAME(ff_cos_64),
+ FFT_NAME(ff_cos_128),
+ FFT_NAME(ff_cos_256),
+ FFT_NAME(ff_cos_512),
+ FFT_NAME(ff_cos_1024),
+ FFT_NAME(ff_cos_2048),
+ FFT_NAME(ff_cos_4096),
+ FFT_NAME(ff_cos_8192),
+ FFT_NAME(ff_cos_16384),
+ FFT_NAME(ff_cos_32768),
+ FFT_NAME(ff_cos_65536),
};
+static void ff_fft_permute_c(FFTContext *s, FFTComplex *z);
+static void ff_fft_calc_c(FFTContext *s, FFTComplex *z);
+
static int split_radix_permutation(int i, int n, int inverse)
{
int m;
else return split_radix_permutation(i, m, inverse)*4 - 1;
}
+av_cold void ff_init_ff_cos_tabs(int index)
+{
+#if !CONFIG_HARDCODED_TABLES
+ int i;
+ int m = 1<<index;
+ double freq = 2*M_PI/m;
+ FFTSample *tab = FFT_NAME(ff_cos_tabs)[index];
+ for(i=0; i<=m/4; i++)
+ tab[i] = FIX15(cos(i*freq));
+ for(i=1; i<m/4; i++)
+ tab[m/2-i] = tab[i];
+#endif
+}
+
+static const int avx_tab[] = {
+ 0, 4, 1, 5, 8, 12, 9, 13, 2, 6, 3, 7, 10, 14, 11, 15
+};
+
+static int is_second_half_of_fft32(int i, int n)
+{
+ if (n <= 32)
+ return i >= 16;
+ else if (i < n/2)
+ return is_second_half_of_fft32(i, n/2);
+ else if (i < 3*n/4)
+ return is_second_half_of_fft32(i - n/2, n/4);
+ else
+ return is_second_half_of_fft32(i - 3*n/4, n/4);
+}
+
+static av_cold void fft_perm_avx(FFTContext *s)
+{
+ int i;
+ int n = 1 << s->nbits;
+
+ for (i = 0; i < n; i += 16) {
+ int k;
+ if (is_second_half_of_fft32(i, n)) {
+ for (k = 0; k < 16; k++)
+ s->revtab[-split_radix_permutation(i + k, n, s->inverse) & (n - 1)] =
+ i + avx_tab[k];
+
+ } else {
+ for (k = 0; k < 16; k++) {
+ int j = i + k;
+ j = (j & ~7) | ((j >> 1) & 3) | ((j << 2) & 4);
+ s->revtab[-split_radix_permutation(i + k, n, s->inverse) & (n - 1)] = j;
+ }
+ }
+ }
+}
+
av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
{
- int i, j, m, n;
- float alpha, c1, s1, s2;
- int split_radix = 1;
- int av_unused has_vectors;
+ int i, j, n;
if (nbits < 2 || nbits > 16)
goto fail;
s->nbits = nbits;
n = 1 << nbits;
- s->tmp_buf = NULL;
- s->exptab = av_malloc((n / 2) * sizeof(FFTComplex));
- if (!s->exptab)
- goto fail;
s->revtab = av_malloc(n * sizeof(uint16_t));
if (!s->revtab)
goto fail;
+ s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
+ if (!s->tmp_buf)
+ goto fail;
s->inverse = inverse;
-
- s2 = inverse ? 1.0 : -1.0;
+ s->fft_permutation = FF_FFT_PERM_DEFAULT;
s->fft_permute = ff_fft_permute_c;
s->fft_calc = ff_fft_calc_c;
+#if CONFIG_MDCT
s->imdct_calc = ff_imdct_calc_c;
s->imdct_half = ff_imdct_half_c;
- s->exptab1 = NULL;
-
-#if HAVE_MMX && HAVE_YASM
- has_vectors = mm_support();
- if (has_vectors & FF_MM_SSE && HAVE_SSE) {
- /* SSE for P3/P4/K8 */
- s->imdct_calc = ff_imdct_calc_sse;
- s->imdct_half = ff_imdct_half_sse;
- s->fft_permute = ff_fft_permute_sse;
- s->fft_calc = ff_fft_calc_sse;
- } else if (has_vectors & FF_MM_3DNOWEXT && HAVE_AMD3DNOWEXT) {
- /* 3DNowEx for K7 */
- s->imdct_calc = ff_imdct_calc_3dn2;
- s->imdct_half = ff_imdct_half_3dn2;
- s->fft_calc = ff_fft_calc_3dn2;
- } else if (has_vectors & FF_MM_3DNOW && HAVE_AMD3DNOW) {
- /* 3DNow! for K6-2/3 */
- s->imdct_calc = ff_imdct_calc_3dn;
- s->imdct_half = ff_imdct_half_3dn;
- s->fft_calc = ff_fft_calc_3dn;
- }
-#elif HAVE_ALTIVEC
- has_vectors = mm_support();
- if (has_vectors & FF_MM_ALTIVEC) {
- s->fft_calc = ff_fft_calc_altivec;
- split_radix = 0;
- }
+ s->mdct_calc = ff_mdct_calc_c;
#endif
- if (split_radix) {
- for(j=4; j<=nbits; j++) {
- int m = 1<<j;
- double freq = 2*M_PI/m;
- FFTSample *tab = ff_cos_tabs[j-4];
- for(i=0; i<=m/4; i++)
- tab[i] = cos(i*freq);
- for(i=1; i<m/4; i++)
- tab[m/2-i] = tab[i];
- }
- for(i=0; i<n; i++)
- s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = i;
- s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
- } else {
- int np, nblocks, np2, l;
- FFTComplex *q;
-
- for(i=0; i<(n/2); i++) {
- alpha = 2 * M_PI * (float)i / (float)n;
- c1 = cos(alpha);
- s1 = sin(alpha) * s2;
- s->exptab[i].re = c1;
- s->exptab[i].im = s1;
- }
+#if CONFIG_FFT_FLOAT
+ if (ARCH_ARM) ff_fft_init_arm(s);
+ if (HAVE_ALTIVEC) ff_fft_init_altivec(s);
+ if (ARCH_X86) ff_fft_init_x86(s);
+ if (CONFIG_MDCT) s->mdct_calcw = s->mdct_calc;
+#else
+ if (CONFIG_MDCT) s->mdct_calcw = ff_mdct_calcw_c;
+ if (ARCH_ARM) ff_fft_fixed_init_arm(s);
+#endif
- np = 1 << nbits;
- nblocks = np >> 3;
- np2 = np >> 1;
- s->exptab1 = av_malloc(np * 2 * sizeof(FFTComplex));
- if (!s->exptab1)
- goto fail;
- q = s->exptab1;
- do {
- for(l = 0; l < np2; l += 2 * nblocks) {
- *q++ = s->exptab[l];
- *q++ = s->exptab[l + nblocks];
-
- q->re = -s->exptab[l].im;
- q->im = s->exptab[l].re;
- q++;
- q->re = -s->exptab[l + nblocks].im;
- q->im = s->exptab[l + nblocks].re;
- q++;
- }
- nblocks = nblocks >> 1;
- } while (nblocks != 0);
- av_freep(&s->exptab);
-
- /* compute bit reverse table */
- for(i=0;i<n;i++) {
- m=0;
- for(j=0;j<nbits;j++) {
- m |= ((i >> j) & 1) << (nbits-j-1);
- }
- s->revtab[i]=m;
+ for(j=4; j<=nbits; j++) {
+ ff_init_ff_cos_tabs(j);
+ }
+
+ if (s->fft_permutation == FF_FFT_PERM_AVX) {
+ fft_perm_avx(s);
+ } else {
+ for(i=0; i<n; i++) {
+ int j = i;
+ if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS)
+ j = (j&~3) | ((j>>1)&1) | ((j<<1)&2);
+ s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = j;
}
}
return 0;
fail:
av_freep(&s->revtab);
- av_freep(&s->exptab);
- av_freep(&s->exptab1);
av_freep(&s->tmp_buf);
return -1;
}
-void ff_fft_permute_c(FFTContext *s, FFTComplex *z)
+static void ff_fft_permute_c(FFTContext *s, FFTComplex *z)
{
- int j, k, np;
- FFTComplex tmp;
+ int j, np;
const uint16_t *revtab = s->revtab;
np = 1 << s->nbits;
-
- if (s->tmp_buf) {
- /* TODO: handle split-radix permute in a more optimal way, probably in-place */
- for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j];
- memcpy(z, s->tmp_buf, np * sizeof(FFTComplex));
- return;
- }
-
- /* reverse */
- for(j=0;j<np;j++) {
- k = revtab[j];
- if (k < j) {
- tmp = z[k];
- z[k] = z[j];
- z[j] = tmp;
- }
- }
+ /* TODO: handle split-radix permute in a more optimal way, probably in-place */
+ for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j];
+ memcpy(z, s->tmp_buf, np * sizeof(FFTComplex));
}
av_cold void ff_fft_end(FFTContext *s)
{
av_freep(&s->revtab);
- av_freep(&s->exptab);
- av_freep(&s->exptab1);
av_freep(&s->tmp_buf);
}
-#define sqrthalf (float)M_SQRT1_2
-
-#define BF(x,y,a,b) {\
- x = a - b;\
- y = a + b;\
-}
-
#define BUTTERFLIES(a0,a1,a2,a3) {\
BF(t3, t5, t5, t1);\
BF(a2.re, a0.re, a0.re, t5);\
}
#define TRANSFORM(a0,a1,a2,a3,wre,wim) {\
- t1 = a2.re * wre + a2.im * wim;\
- t2 = a2.im * wre - a2.re * wim;\
- t5 = a3.re * wre - a3.im * wim;\
- t6 = a3.im * wre + a3.re * wim;\
+ CMUL(t1, t2, a2.re, a2.im, wre, -wim);\
+ CMUL(t5, t6, a3.re, a3.im, wre, wim);\
BUTTERFLIES(a0,a1,a2,a3)\
}
#define PASS(name)\
static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\
{\
- FFTSample t1, t2, t3, t4, t5, t6;\
+ FFTDouble t1, t2, t3, t4, t5, t6;\
int o1 = 2*n;\
int o2 = 4*n;\
int o3 = 6*n;\
fft##n2(z);\
fft##n4(z+n4*2);\
fft##n4(z+n4*3);\
- pass(z,ff_cos_##n,n4/2);\
+ pass(z,FFT_NAME(ff_cos_##n),n4/2);\
}
static void fft4(FFTComplex *z)
{
- FFTSample t1, t2, t3, t4, t5, t6, t7, t8;
+ FFTDouble t1, t2, t3, t4, t5, t6, t7, t8;
BF(t3, t1, z[0].re, z[1].re);
BF(t8, t6, z[3].re, z[2].re);
static void fft8(FFTComplex *z)
{
- FFTSample t1, t2, t3, t4, t5, t6, t7, t8;
+ FFTDouble t1, t2, t3, t4, t5, t6;
fft4(z);
BF(t1, z[5].re, z[4].re, -z[5].re);
BF(t2, z[5].im, z[4].im, -z[5].im);
- BF(t3, z[7].re, z[6].re, -z[7].re);
- BF(t4, z[7].im, z[6].im, -z[7].im);
- BF(t8, t1, t3, t1);
- BF(t7, t2, t2, t4);
- BF(z[4].re, z[0].re, z[0].re, t1);
- BF(z[4].im, z[0].im, z[0].im, t2);
- BF(z[6].re, z[2].re, z[2].re, t7);
- BF(z[6].im, z[2].im, z[2].im, t8);
+ BF(t5, z[7].re, z[6].re, -z[7].re);
+ BF(t6, z[7].im, z[6].im, -z[7].im);
+ BUTTERFLIES(z[0],z[2],z[4],z[6]);
TRANSFORM(z[1],z[3],z[5],z[7],sqrthalf,sqrthalf);
}
#if !CONFIG_SMALL
static void fft16(FFTComplex *z)
{
- FFTSample t1, t2, t3, t4, t5, t6;
+ FFTDouble t1, t2, t3, t4, t5, t6;
+ FFTSample cos_16_1 = FFT_NAME(ff_cos_16)[1];
+ FFTSample cos_16_3 = FFT_NAME(ff_cos_16)[3];
fft8(z);
fft4(z+8);
TRANSFORM_ZERO(z[0],z[4],z[8],z[12]);
TRANSFORM(z[2],z[6],z[10],z[14],sqrthalf,sqrthalf);
- TRANSFORM(z[1],z[5],z[9],z[13],ff_cos_16[1],ff_cos_16[3]);
- TRANSFORM(z[3],z[7],z[11],z[15],ff_cos_16[3],ff_cos_16[1]);
+ TRANSFORM(z[1],z[5],z[9],z[13],cos_16_1,cos_16_3);
+ TRANSFORM(z[3],z[7],z[11],z[15],cos_16_3,cos_16_1);
}
#else
DECL_FFT(16,8,4)
DECL_FFT(32768,16384,8192)
DECL_FFT(65536,32768,16384)
-static void (*fft_dispatch[])(FFTComplex*) = {
+static void (* const fft_dispatch[])(FFTComplex*) = {
fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024,
fft2048, fft4096, fft8192, fft16384, fft32768, fft65536,
};
-void ff_fft_calc_c(FFTContext *s, FFTComplex *z)
+static void ff_fft_calc_c(FFTContext *s, FFTComplex *z)
{
fft_dispatch[s->nbits-2](z);
}
-
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