1/* 2 * This file is part of FFmpeg. 3 * 4 * FFmpeg is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * FFmpeg is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with FFmpeg; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19#define FFT_FLOAT 0 20#define FFT_FIXED_32 0 21#include "mdct_template.c" 22 23/* same as ff_mdct_calcw_c with double-width unscaled output */ 24void ff_mdct_calcw_c(FFTContext *s, FFTDouble *out, const FFTSample *input) 25{ 26 int i, j, n, n8, n4, n2, n3; 27 FFTDouble re, im; 28 const uint16_t *revtab = s->revtab; 29 const FFTSample *tcos = s->tcos; 30 const FFTSample *tsin = s->tsin; 31 FFTComplex *x = s->tmp_buf; 32 FFTDComplex *o = (FFTDComplex *)out; 33 34 n = 1 << s->mdct_bits; 35 n2 = n >> 1; 36 n4 = n >> 2; 37 n8 = n >> 3; 38 n3 = 3 * n4; 39 40 /* pre rotation */ 41 for(i=0;i<n8;i++) { 42 re = RSCALE(-input[2*i+n3] - input[n3-1-2*i]); 43 im = RSCALE(-input[n4+2*i] + input[n4-1-2*i]); 44 j = revtab[i]; 45 CMUL(x[j].re, x[j].im, re, im, -tcos[i], tsin[i]); 46 47 re = RSCALE( input[2*i] - input[n2-1-2*i]); 48 im = RSCALE(-input[n2+2*i] - input[ n-1-2*i]); 49 j = revtab[n8 + i]; 50 CMUL(x[j].re, x[j].im, re, im, -tcos[n8 + i], tsin[n8 + i]); 51 } 52 53 s->fft_calc(s, x); 54 55 /* post rotation */ 56 for(i=0;i<n8;i++) { 57 FFTDouble r0, i0, r1, i1; 58 CMULL(i1, r0, x[n8-i-1].re, x[n8-i-1].im, -tsin[n8-i-1], -tcos[n8-i-1]); 59 CMULL(i0, r1, x[n8+i ].re, x[n8+i ].im, -tsin[n8+i ], -tcos[n8+i ]); 60 o[n8-i-1].re = r0; 61 o[n8-i-1].im = i0; 62 o[n8+i ].re = r1; 63 o[n8+i ].im = i1; 64 } 65} 66