cfft.c

tcpmp.src.0.72RC1 优秀的多媒体播放器TCPMP的源代码

/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through [e-mail].
**
** $Id: cfft.c,v 1.30 2004/09/08 09:43:11 gcp Exp $
**/

/*
 * Algorithmically based on Fortran-77 FFTPACK
 * by Paul N. Swarztrauber(Version 4, 1985).
 *
 * Does even sized fft only
 */

/* isign is +1 for backward and -1 for forward transforms */

#include "common.h"
#include "structs.h"

#include <stdlib.h>

#ifndef LIBPAAC

#include "cfft.h"
#include "cfft_tab.h"


/* static function declarations */
static void passf2pos(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                      complex_t *ch, const complex_t *wa);
static void passf2neg(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                      complex_t *ch, const complex_t *wa);
static void passf3(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                   complex_t *ch, const complex_t *wa1, const complex_t *wa2, const int8_t isign);
static void passf4pos(const uint16_t ido, const uint16_t l1, const complex_t *cc, complex_t *ch,
                      const complex_t *wa1, const complex_t *wa2, const complex_t *wa3);
static void passf4neg(const uint16_t ido, const uint16_t l1, const complex_t *cc, complex_t *ch,
                      const complex_t *wa1, const complex_t *wa2, const complex_t *wa3);
static void passf5(const uint16_t ido, const uint16_t l1, const complex_t *cc, complex_t *ch,
                   const complex_t *wa1, const complex_t *wa2, const complex_t *wa3,
                   const complex_t *wa4, const int8_t isign);
INLINE void cfftf1(uint16_t n, complex_t *c, complex_t *ch,
                   const uint16_t *ifac, const complex_t *wa, const int8_t isign);
static void cffti1(uint16_t n, complex_t *wa, uint16_t *ifac);


/*----------------------------------------------------------------------
   passf2, passf3, passf4, passf5. Complex FFT passes fwd and bwd.
  ----------------------------------------------------------------------*/

static void passf2pos(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                      complex_t *ch, const complex_t *wa)
{
    uint16_t i, k, ah, ac;

    if (ido == 1)
    {
        for (k = 0; k < l1; k++)
        {
            ah = 2*k;
            ac = 4*k;

            RE(ch[ah])    = RE(cc[ac]) + RE(cc[ac+1]);
            RE(ch[ah+l1]) = RE(cc[ac]) - RE(cc[ac+1]);
            IM(ch[ah])    = IM(cc[ac]) + IM(cc[ac+1]);
            IM(ch[ah+l1]) = IM(cc[ac]) - IM(cc[ac+1]);
        }
    } else {
        for (k = 0; k < l1; k++)
        {
            ah = k*ido;
            ac = 2*k*ido;

            for (i = 0; i < ido; i++)
            {
                complex_t t2;

                RE(ch[ah+i]) = RE(cc[ac+i]) + RE(cc[ac+i+ido]);
                RE(t2)       = RE(cc[ac+i]) - RE(cc[ac+i+ido]);

                IM(ch[ah+i]) = IM(cc[ac+i]) + IM(cc[ac+i+ido]);
                IM(t2)       = IM(cc[ac+i]) - IM(cc[ac+i+ido]);

#if 1
                ComplexMult(&IM(ch[ah+i+l1*ido]), &RE(ch[ah+i+l1*ido]),
                    IM(t2), RE(t2), RE(wa[i]), IM(wa[i]));
#else
                ComplexMult(&RE(ch[ah+i+l1*ido]), &IM(ch[ah+i+l1*ido]),
                    RE(t2), IM(t2), RE(wa[i]), IM(wa[i]));
#endif
            }
        }
    }
}

static void passf2neg(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                      complex_t *ch, const complex_t *wa)
{
    uint16_t i, k, ah, ac;

    if (ido == 1)
    {
        for (k = 0; k < l1; k++)
        {
            ah = 2*k;
            ac = 4*k;

            RE(ch[ah])    = RE(cc[ac]) + RE(cc[ac+1]);
            RE(ch[ah+l1]) = RE(cc[ac]) - RE(cc[ac+1]);
            IM(ch[ah])    = IM(cc[ac]) + IM(cc[ac+1]);
            IM(ch[ah+l1]) = IM(cc[ac]) - IM(cc[ac+1]);
        }
    } else {
        for (k = 0; k < l1; k++)
        {
            ah = k*ido;
            ac = 2*k*ido;

            for (i = 0; i < ido; i++)
            {
                complex_t t2;

                RE(ch[ah+i]) = RE(cc[ac+i]) + RE(cc[ac+i+ido]);
                RE(t2)       = RE(cc[ac+i]) - RE(cc[ac+i+ido]);

                IM(ch[ah+i]) = IM(cc[ac+i]) + IM(cc[ac+i+ido]);
                IM(t2)       = IM(cc[ac+i]) - IM(cc[ac+i+ido]);

#if 1
                ComplexMult(&RE(ch[ah+i+l1*ido]), &IM(ch[ah+i+l1*ido]),
                    RE(t2), IM(t2), RE(wa[i]), IM(wa[i]));
#else
                ComplexMult(&IM(ch[ah+i+l1*ido]), &RE(ch[ah+i+l1*ido]),
                    IM(t2), RE(t2), RE(wa[i]), IM(wa[i]));
#endif
            }
        }
    }
}


static void passf3(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                   complex_t *ch, const complex_t *wa1, const complex_t *wa2,
                   const int8_t isign)
{
    static const real_t taur = FRAC_CONST(-0.5);
    static const real_t taui = FRAC_CONST(0.866025403784439);
    uint16_t i, k, ac, ah;
    complex_t c2, c3, d2, d3, t2;

    if (ido == 1)
    {
        if (isign == 1)
        {
            for (k = 0; k < l1; k++)
            {
                ac = 3*k+1;
                ah = k;

                RE(t2) = RE(cc[ac]) + RE(cc[ac+1]);
                IM(t2) = IM(cc[ac]) + IM(cc[ac+1]);
                RE(c2) = RE(cc[ac-1]) + MUL_F(RE(t2),taur);
                IM(c2) = IM(cc[ac-1]) + MUL_F(IM(t2),taur);

                RE(ch[ah]) = RE(cc[ac-1]) + RE(t2);
                IM(ch[ah]) = IM(cc[ac-1]) + IM(t2);

                RE(c3) = MUL_F((RE(cc[ac]) - RE(cc[ac+1])), taui);
                IM(c3) = MUL_F((IM(cc[ac]) - IM(cc[ac+1])), taui);

                RE(ch[ah+l1]) = RE(c2) - IM(c3);
                IM(ch[ah+l1]) = IM(c2) + RE(c3);
                RE(ch[ah+2*l1]) = RE(c2) + IM(c3);
                IM(ch[ah+2*l1]) = IM(c2) - RE(c3);
            }
        } else {
            for (k = 0; k < l1; k++)
            {
                ac = 3*k+1;
                ah = k;

                RE(t2) = RE(cc[ac]) + RE(cc[ac+1]);
                IM(t2) = IM(cc[ac]) + IM(cc[ac+1]);
                RE(c2) = RE(cc[ac-1]) + MUL_F(RE(t2),taur);
                IM(c2) = IM(cc[ac-1]) + MUL_F(IM(t2),taur);

                RE(ch[ah]) = RE(cc[ac-1]) + RE(t2);
                IM(ch[ah]) = IM(cc[ac-1]) + IM(t2);

                RE(c3) = MUL_F((RE(cc[ac]) - RE(cc[ac+1])), taui);
                IM(c3) = MUL_F((IM(cc[ac]) - IM(cc[ac+1])), taui);

                RE(ch[ah+l1]) = RE(c2) + IM(c3);
                IM(ch[ah+l1]) = IM(c2) - RE(c3);
                RE(ch[ah+2*l1]) = RE(c2) - IM(c3);
                IM(ch[ah+2*l1]) = IM(c2) + RE(c3);
            }
        }
    } else {
        if (isign == 1)
        {
            for (k = 0; k < l1; k++)
            {
                for (i = 0; i < ido; i++)
                {
                    ac = i + (3*k+1)*ido;
                    ah = i + k * ido;

                    RE(t2) = RE(cc[ac]) + RE(cc[ac+ido]);
                    RE(c2) = RE(cc[ac-ido]) + MUL_F(RE(t2),taur);
                    IM(t2) = IM(cc[ac]) + IM(cc[ac+ido]);
                    IM(c2) = IM(cc[ac-ido]) + MUL_F(IM(t2),taur);

                    RE(ch[ah]) = RE(cc[ac-ido]) + RE(t2);
                    IM(ch[ah]) = IM(cc[ac-ido]) + IM(t2);

                    RE(c3) = MUL_F((RE(cc[ac]) - RE(cc[ac+ido])), taui);
                    IM(c3) = MUL_F((IM(cc[ac]) - IM(cc[ac+ido])), taui);

                    RE(d2) = RE(c2) - IM(c3);
                    IM(d3) = IM(c2) - RE(c3);
                    RE(d3) = RE(c2) + IM(c3);
                    IM(d2) = IM(c2) + RE(c3);

#if 1
                    ComplexMult(&IM(ch[ah+l1*ido]), &RE(ch[ah+l1*ido]),
                        IM(d2), RE(d2), RE(wa1[i]), IM(wa1[i]));
                    ComplexMult(&IM(ch[ah+2*l1*ido]), &RE(ch[ah+2*l1*ido]),
                        IM(d3), RE(d3), RE(wa2[i]), IM(wa2[i]));
#else
                    ComplexMult(&RE(ch[ah+l1*ido]), &IM(ch[ah+l1*ido]),
                        RE(d2), IM(d2), RE(wa1[i]), IM(wa1[i]));
                    ComplexMult(&RE(ch[ah+2*l1*ido]), &IM(ch[ah+2*l1*ido]),
                        RE(d3), IM(d3), RE(wa2[i]), IM(wa2[i]));
#endif
                }
            }
        } else {
            for (k = 0; k < l1; k++)
            {
                for (i = 0; i < ido; i++)
                {
                    ac = i + (3*k+1)*ido;
                    ah = i + k * ido;

                    RE(t2) = RE(cc[ac]) + RE(cc[ac+ido]);
                    RE(c2) = RE(cc[ac-ido]) + MUL_F(RE(t2),taur);
                    IM(t2) = IM(cc[ac]) + IM(cc[ac+ido]);
                    IM(c2) = IM(cc[ac-ido]) + MUL_F(IM(t2),taur);

                    RE(ch[ah]) = RE(cc[ac-ido]) + RE(t2);
                    IM(ch[ah]) = IM(cc[ac-ido]) + IM(t2);

                    RE(c3) = MUL_F((RE(cc[ac]) - RE(cc[ac+ido])), taui);
                    IM(c3) = MUL_F((IM(cc[ac]) - IM(cc[ac+ido])), taui);

                    RE(d2) = RE(c2) + IM(c3);
                    IM(d3) = IM(c2) + RE(c3);
                    RE(d3) = RE(c2) - IM(c3);
                    IM(d2) = IM(c2) - RE(c3);

#if 1
                    ComplexMult(&RE(ch[ah+l1*ido]), &IM(ch[ah+l1*ido]),
                        RE(d2), IM(d2), RE(wa1[i]), IM(wa1[i]));
                    ComplexMult(&RE(ch[ah+2*l1*ido]), &IM(ch[ah+2*l1*ido]),
                        RE(d3), IM(d3), RE(wa2[i]), IM(wa2[i]));
#else
                    ComplexMult(&IM(ch[ah+l1*ido]), &RE(ch[ah+l1*ido]),
                        IM(d2), RE(d2), RE(wa1[i]), IM(wa1[i]));
                    ComplexMult(&IM(ch[ah+2*l1*ido]), &RE(ch[ah+2*l1*ido]),
                        IM(d3), RE(d3), RE(wa2[i]), IM(wa2[i]));
#endif
                }
            }
        }
    }
}


static void passf4pos(const uint16_t ido, const uint16_t l1, const complex_t *cc,
                      complex_t *ch, const complex_t *wa1, const complex_t *wa2,
                      const complex_t *wa3)
{
    uint16_t i, k, ac, ah;

    if (ido == 1)
    {
        for (k = 0; k < l1; k++)
        {
            complex_t t1, t2, t3, t4;

            ac = 4*k;
            ah = k;

            RE(t2) = RE(cc[ac])   + RE(cc[ac+2]);
            RE(t1) = RE(cc[ac])   - RE(cc[ac+2]);
            IM(t2) = IM(cc[ac])   + IM(cc[ac+2]);
            IM(t1) = IM(cc[ac])   - IM(cc[ac+2]);
            RE(t3) = RE(cc[ac+1]) + RE(cc[ac+3]);
            IM(t4) = RE(cc[ac+1]) - RE(cc[ac+3]);
            IM(t3) = IM(cc[ac+3]) + IM(cc[ac+1]);
            RE(t4) = IM(cc[ac+3]) - IM(cc[ac+1]);

            RE(ch[ah])      = RE(t2) + RE(t3);
            RE(ch[ah+2*l1]) = RE(t2) - RE(t3);

            IM(ch[ah])      = IM(t2) + IM(t3);
            IM(ch[ah+2*l1]) = IM(t2) - IM(t3);

            RE(ch[ah+l1])   = RE(t1) + RE(t4);
            RE(ch[ah+3*l1]) = RE(t1) - RE(t4);

            IM(ch[ah+l1])   = IM(t1) + IM(t4);
            IM(ch[ah+3*l1]) = IM(t1) - IM(t4);
        }
    } else {