| 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 */ |
| 24 | void 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 | } |