| 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 */ |
| 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 | } |