1 /*
2 * Copyright (c) 2011 Mans Rullgard
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "config.h"
22 #include "libavutil/attributes.h"
23 #include "libavutil/thread.h"
24 #include "mpegaudio.h"
25 #include "mpegaudiodsp.h"
26 #include "dct.h"
27 #include "dct32.h"
28
29 static AVOnce mpadsp_table_init = AV_ONCE_INIT;
30
mpadsp_init_tabs(void)31 static av_cold void mpadsp_init_tabs(void)
32 {
33 int i, j;
34 /* compute mdct windows */
35 for (i = 0; i < 36; i++) {
36 for (j = 0; j < 4; j++) {
37 double d;
38
39 if (j == 2 && i % 3 != 1)
40 continue;
41
42 d = sin(M_PI * (i + 0.5) / 36.0);
43 if (j == 1) {
44 if (i >= 30) d = 0;
45 else if (i >= 24) d = sin(M_PI * (i - 18 + 0.5) / 12.0);
46 else if (i >= 18) d = 1;
47 } else if (j == 3) {
48 if (i < 6) d = 0;
49 else if (i < 12) d = sin(M_PI * (i - 6 + 0.5) / 12.0);
50 else if (i < 18) d = 1;
51 }
52 //merge last stage of imdct into the window coefficients
53 d *= 0.5 * IMDCT_SCALAR / cos(M_PI * (2 * i + 19) / 72);
54
55 if (j == 2) {
56 ff_mdct_win_float[j][i/3] = d / (1 << 5);
57 ff_mdct_win_fixed[j][i/3] = d / (1 << 5) * (1LL << 32) + 0.5;
58 } else {
59 int idx = i < 18 ? i : i + (MDCT_BUF_SIZE/2 - 18);
60 ff_mdct_win_float[j][idx] = d / (1 << 5);
61 ff_mdct_win_fixed[j][idx] = d / (1 << 5) * (1LL << 32) + 0.5;
62 }
63 }
64 }
65
66 /* NOTE: we do frequency inversion after the MDCT by changing
67 the sign of the right window coefs */
68 for (j = 0; j < 4; j++) {
69 for (i = 0; i < MDCT_BUF_SIZE; i += 2) {
70 ff_mdct_win_float[j + 4][i ] = ff_mdct_win_float[j][i ];
71 ff_mdct_win_float[j + 4][i + 1] = -ff_mdct_win_float[j][i + 1];
72 ff_mdct_win_fixed[j + 4][i ] = ff_mdct_win_fixed[j][i ];
73 ff_mdct_win_fixed[j + 4][i + 1] = -ff_mdct_win_fixed[j][i + 1];
74 }
75 }
76
77 if (ARCH_X86)
78 ff_mpadsp_init_x86_tabs();
79 }
80
ff_mpadsp_init(MPADSPContext * s)81 av_cold void ff_mpadsp_init(MPADSPContext *s)
82 {
83 DCTContext dct;
84
85 ff_dct_init(&dct, 5, DCT_II);
86 ff_thread_once(&mpadsp_table_init, &mpadsp_init_tabs);
87
88 s->apply_window_float = ff_mpadsp_apply_window_float;
89 s->apply_window_fixed = ff_mpadsp_apply_window_fixed;
90
91 s->dct32_float = dct.dct32;
92 s->dct32_fixed = ff_dct32_fixed;
93
94 s->imdct36_blocks_float = ff_imdct36_blocks_float;
95 s->imdct36_blocks_fixed = ff_imdct36_blocks_fixed;
96
97 if (ARCH_AARCH64) ff_mpadsp_init_aarch64(s);
98 if (ARCH_ARM) ff_mpadsp_init_arm(s);
99 if (ARCH_PPC) ff_mpadsp_init_ppc(s);
100 if (ARCH_X86) ff_mpadsp_init_x86(s);
101 if (HAVE_MIPSFPU) ff_mpadsp_init_mipsfpu(s);
102 if (HAVE_MIPSDSP) ff_mpadsp_init_mipsdsp(s);
103 }
104