* FFT/IFFT transforms
* Copyright (c) 2002 Fabrice Bellard.
*
- * This library is free software; you can redistribute it and/or
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * FFmpeg 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+
+/**
+ * @file fft.c
+ * FFT/IFFT transforms.
+ */
+
#include "dsputil.h"
/**
* The size of the FFT is 2^nbits. If inverse is TRUE, inverse FFT is
- * done
+ * done
*/
-int fft_init(FFTContext *s, int nbits, int inverse)
+int ff_fft_init(FFTContext *s, int nbits, int inverse)
{
int i, j, m, n;
float alpha, c1, s1, s2;
-
+
s->nbits = nbits;
n = 1 << nbits;
s->inverse = inverse;
s2 = inverse ? 1.0 : -1.0;
-
+
for(i=0;i<(n/2);i++) {
alpha = 2 * M_PI * (float)i / (float)n;
c1 = cos(alpha);
s->exptab[i].re = c1;
s->exptab[i].im = s1;
}
- s->fft_calc = fft_calc_c;
+ s->fft_calc = ff_fft_calc_c;
+ s->imdct_calc = ff_imdct_calc;
s->exptab1 = NULL;
/* compute constant table for HAVE_SSE version */
-#if defined(HAVE_MMX) && 0
- if (mm_flags & MM_SSE) {
- int np, nblocks, np2, l;
- FFTComplex *q;
-
- 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];
+#if defined(HAVE_MMX) \
+ || (defined(HAVE_ALTIVEC) && !defined(ALTIVEC_USE_REFERENCE_C_CODE))
+ {
+ int has_vectors = mm_support();
- 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++;
+ if (has_vectors) {
+#if defined(HAVE_MMX)
+ if (has_vectors & MM_3DNOWEXT) {
+ /* 3DNowEx for K7/K8 */
+ s->imdct_calc = ff_imdct_calc_3dn2;
+ s->fft_calc = ff_fft_calc_3dn2;
+ } else if (has_vectors & MM_3DNOW) {
+ /* 3DNow! for K6-2/3 */
+ s->fft_calc = ff_fft_calc_3dn;
+ } else if (has_vectors & MM_SSE) {
+ /* SSE for P3/P4 */
+ s->imdct_calc = ff_imdct_calc_sse;
+ s->fft_calc = ff_fft_calc_sse;
}
- nblocks = nblocks >> 1;
- } while (nblocks != 0);
- av_freep(&s->exptab);
+#else /* HAVE_MMX */
+ if (has_vectors & MM_ALTIVEC)
+ s->fft_calc = ff_fft_calc_altivec;
+#endif
+ }
+ if (s->fft_calc != ff_fft_calc_c) {
+ int np, nblocks, np2, l;
+ FFTComplex *q;
+
+ 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);
+ }
}
#endif
}
/**
- * Do a complex FFT with the parameters defined in fft_init(). The
+ * Do a complex FFT with the parameters defined in ff_fft_init(). The
* input data must be permuted before with s->revtab table. No
- * 1.0/sqrt(n) normalization is done.
+ * 1.0/sqrt(n) normalization is done.
*/
-void fft_calc_c(FFTContext *s, FFTComplex *z)
+void ff_fft_calc_c(FFTContext *s, FFTComplex *z)
{
int ln = s->nbits;
- int j, np, np2;
- int nblocks, nloops;
+ int j, np, np2;
+ int nblocks, nloops;
register FFTComplex *p, *q;
FFTComplex *exptab = s->exptab;
int l;
p=&z[0];
j=(np >> 1);
do {
- BF(p[0].re, p[0].im, p[1].re, p[1].im,
+ BF(p[0].re, p[0].im, p[1].re, p[1].im,
p[0].re, p[0].im, p[1].re, p[1].im);
p+=2;
} while (--j != 0);
/* pass 1 */
-
+
p=&z[0];
j=np >> 2;
if (s->inverse) {
do {
- BF(p[0].re, p[0].im, p[2].re, p[2].im,
+ BF(p[0].re, p[0].im, p[2].re, p[2].im,
p[0].re, p[0].im, p[2].re, p[2].im);
- BF(p[1].re, p[1].im, p[3].re, p[3].im,
+ BF(p[1].re, p[1].im, p[3].re, p[3].im,
p[1].re, p[1].im, -p[3].im, p[3].re);
p+=4;
} while (--j != 0);
} else {
do {
- BF(p[0].re, p[0].im, p[2].re, p[2].im,
+ BF(p[0].re, p[0].im, p[2].re, p[2].im,
p[0].re, p[0].im, p[2].re, p[2].im);
- BF(p[1].re, p[1].im, p[3].re, p[3].im,
+ BF(p[1].re, p[1].im, p[3].re, p[3].im,
p[1].re, p[1].im, p[3].im, -p[3].re);
p+=4;
} while (--j != 0);
for (j = 0; j < nblocks; ++j) {
BF(p->re, p->im, q->re, q->im,
p->re, p->im, q->re, q->im);
-
+
p++;
q++;
for(l = nblocks; l < np2; l += nblocks) {
}
/**
- * Do the permutation needed BEFORE calling fft_calc()
+ * Do the permutation needed BEFORE calling ff_fft_calc()
*/
-void fft_permute(FFTContext *s, FFTComplex *z)
+void ff_fft_permute(FFTContext *s, FFTComplex *z)
{
int j, k, np;
FFTComplex tmp;
const uint16_t *revtab = s->revtab;
-
+
/* reverse */
np = 1 << s->nbits;
for(j=0;j<np;j++) {
}
}
-void fft_end(FFTContext *s)
+void ff_fft_end(FFTContext *s)
{
av_freep(&s->revtab);
av_freep(&s->exptab);
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