2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
3 ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
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.
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.
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.
19 ** Any non-GPL usage of this software or parts of this software is strictly
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"
25 ** Commercial non-GPL licensing of this software is possible.
26 ** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
28 ** $Id: ms.c,v 1.21 2007/11/01 12:33:32 menno Exp $
39 void ms_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec,
44 uint16_t nshort = frame_len/8;
49 if (ics->ms_mask_present >= 1)
51 for (g = 0; g < ics->num_window_groups; g++)
53 for (b = 0; b < ics->window_group_length[g]; b++)
55 for (sfb = 0; sfb < ics->max_sfb; sfb++)
57 /* If intensity stereo coding or noise substitution is on
58 for a particular scalefactor band, no M/S stereo decoding
61 if ((ics->ms_used[g][sfb] || ics->ms_mask_present == 2) &&
62 !is_intensity(icsr, g, sfb) && !is_noise(ics, g, sfb))
64 for (i = ics->swb_offset[sfb]; i < min(ics->swb_offset[sfb+1], ics->swb_offset_max); i++)
66 k = (group*nshort) + i;
67 tmp = l_spec[k] - r_spec[k];
68 l_spec[k] = l_spec[k] + r_spec[k];