1 /*
2 * MPEG Audio common code
3 * Copyright (c) 2001, 2002 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * MPEG Audio common code.
25 */
26
27 #include "mpegaudio.h"
28
29
30 /* bitrate is in kb/s */
ff_mpa_l2_select_table(int bitrate,int nb_channels,int freq,int lsf)31 int ff_mpa_l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
32 {
33 int ch_bitrate, table;
34
35 ch_bitrate = bitrate / nb_channels;
36 if (!lsf) {
37 if ((freq == 48000 && ch_bitrate >= 56) ||
38 (ch_bitrate >= 56 && ch_bitrate <= 80))
39 table = 0;
40 else if (freq != 48000 && ch_bitrate >= 96)
41 table = 1;
42 else if (freq != 32000 && ch_bitrate <= 48)
43 table = 2;
44 else
45 table = 3;
46 } else {
47 table = 4;
48 }
49 return table;
50 }
51