1 /*
2 * The simplest AC-3 encoder
3 * Copyright (c) 2000 Fabrice Bellard
4 * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
5 * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /**
25 * @file
26 * fixed-point AC-3 encoder.
27 */
28
29 #define AC3ENC_FLOAT 0
36
40 {
41 s->ac3dsp.sum_square_butterfly_int32(sum, coef0, coef1,
len);
42 }
43
44 /*
45 * Clip MDCT coefficients to allowable range.
46 */
49 {
51 }
52
53
54 /*
55 * Calculate a single coupling coordinate.
56 */
58 {
60 return 1048576;
61 } else {
62 uint64_t coord = energy_ch / (energy_cpl >> 24);
63 uint32_t coord32 =
FFMIN(coord, 1073741824);
64 coord32 =
ff_sqrt(coord32) << 9;
66 }
67 }
68
69
71
72
73 /**
74 * Finalize MDCT and free allocated memory.
75 *
76 * @param s AC-3 encoder private context
77 */
79 {
81 }
82
83 /**
84 * Initialize MDCT tables.
85 *
86 * @param s AC-3 encoder private context
87 * @return 0 on success, negative error code on failure
88 */
90 {
92
94 if (!iwin)
96
99 iwin[
i] =
lrintf(fwin[
i] * (1 << 22));
100
101 s->mdct_window = iwin;
102
106
108 }
109
110
112 {
119 }
120
121
139 };