blob: a32cb00ca03608241dfa51b1c4a663eeecd7c0a8
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 | } |
66 |