blob: 7eaa4c6df19cad0c509d9736dfd3193eacf31247
| 1 | /* |
| 2 | ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding |
| 3 | ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com |
| 4 | ** |
| 5 | ** This program is free software; you can redistribute it and/or modify |
| 6 | ** it under the terms of the GNU General Public License as published by |
| 7 | ** the Free Software Foundation; either version 2 of the License, or |
| 8 | ** (at your option) any later version. |
| 9 | ** |
| 10 | ** This program is distributed in the hope that it will be useful, |
| 11 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | ** GNU General Public License for more details. |
| 14 | ** |
| 15 | ** You should have received a copy of the GNU General Public License |
| 16 | ** along with this program; if not, write to the Free Software |
| 17 | ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 18 | ** |
| 19 | ** Any non-GPL usage of this software or parts of this software is strictly |
| 20 | ** forbidden. |
| 21 | ** |
| 22 | ** The "appropriate copyright message" mentioned in section 2c of the GPLv2 |
| 23 | ** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com" |
| 24 | ** |
| 25 | ** Commercial non-GPL licensing of this software is possible. |
| 26 | ** For more info contact Nero AG through Mpeg4AAClicense@nero.com. |
| 27 | ** |
| 28 | ** $Id: ms.c,v 1.21 2007/11/01 12:33:32 menno Exp $ |
| 29 | **/ |
| 30 | |
| 31 | #include "common.h" |
| 32 | #include "structs.h" |
| 33 | |
| 34 | #include "syntax.h" |
| 35 | #include "ms.h" |
| 36 | #include "is.h" |
| 37 | #include "pns.h" |
| 38 | |
| 39 | void ms_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec, |
| 40 | uint16_t frame_len) |
| 41 | { |
| 42 | uint8_t g, b, sfb; |
| 43 | uint8_t group = 0; |
| 44 | uint16_t nshort = frame_len / 8; |
| 45 | |
| 46 | uint16_t i, k; |
| 47 | real_t tmp; |
| 48 | |
| 49 | if (ics->ms_mask_present >= 1) { |
| 50 | for (g = 0; g < ics->num_window_groups; g++) { |
| 51 | for (b = 0; b < ics->window_group_length[g]; b++) { |
| 52 | for (sfb = 0; sfb < ics->max_sfb; sfb++) { |
| 53 | /* If intensity stereo coding or noise substitution is on |
| 54 | for a particular scalefactor band, no M/S stereo decoding |
| 55 | is carried out. |
| 56 | */ |
| 57 | if ((ics->ms_used[g][sfb] || ics->ms_mask_present == 2) && |
| 58 | !is_intensity(icsr, g, sfb) && !is_noise(ics, g, sfb)) { |
| 59 | for (i = ics->swb_offset[sfb]; i < min(ics->swb_offset[sfb + 1], ics->swb_offset_max); i++) { |
| 60 | k = (group * nshort) + i; |
| 61 | tmp = l_spec[k] - r_spec[k]; |
| 62 | l_spec[k] = l_spec[k] + r_spec[k]; |
| 63 | r_spec[k] = tmp; |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | group++; |
| 68 | } |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 |