1/* 2 * This file is part of Libav. 3 * 4 * Libav 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 * Libav 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 Libav; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19#define CONFIG_FFT_FLOAT 0 20#include "mdct.c" 21 22/* same as ff_mdct_calcw_c with double-width unscaled output */ 23void ff_mdct_calcw_c(FFTContext *s, FFTDouble *out, const FFTSample *input) 24{ 25 int i, j, n, n8, n4, n2, n3; 26 FFTDouble re, im; 27 const uint16_t *revtab = s->revtab; 28 const FFTSample *tcos = s->tcos; 29 const FFTSample *tsin = s->tsin; 30 FFTComplex *x = s->tmp_buf; 31 FFTDComplex *o = (FFTDComplex *)out; 32 33 n = 1 << s->mdct_bits; 34 n2 = n >> 1; 35 n4 = n >> 2; 36 n8 = n >> 3; 37 n3 = 3 * n4; 38 39 /* pre rotation */ 40 for(i=0;i<n8;i++) { 41 re = RSCALE(-input[2*i+n3] - input[n3-1-2*i]); 42 im = RSCALE(-input[n4+2*i] + input[n4-1-2*i]); 43 j = revtab[i]; 44 CMUL(x[j].re, x[j].im, re, im, -tcos[i], tsin[i]); 45 46 re = RSCALE( input[2*i] - input[n2-1-2*i]); 47 im = RSCALE(-input[n2+2*i] - input[ n-1-2*i]); 48 j = revtab[n8 + i]; 49 CMUL(x[j].re, x[j].im, re, im, -tcos[n8 + i], tsin[n8 + i]); 50 } 51 52 s->fft_calc(s, x); 53 54 /* post rotation */ 55 for(i=0;i<n8;i++) { 56 FFTDouble r0, i0, r1, i1; 57 CMULL(i1, r0, x[n8-i-1].re, x[n8-i-1].im, -tsin[n8-i-1], -tcos[n8-i-1]); 58 CMULL(i0, r1, x[n8+i ].re, x[n8+i ].im, -tsin[n8+i ], -tcos[n8+i ]); 59 o[n8-i-1].re = r0; 60 o[n8-i-1].im = i0; 61 o[n8+i ].re = r1; 62 o[n8+i ].im = i1; 63 } 64} 65