ref: e2d3ad8e2ba155aa097735c4b0376f361521fbc2
dir: /libfaad/ms.c/
/* ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com ** ** This program is free software; you can redistribute it and/or modify ** it under the terms of the GNU General Public License as published by ** the Free Software Foundation; either version 2 of the License, or ** (at your option) any later version. ** ** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with this program; if not, write to the Free Software ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ** ** Any non-GPL usage of this software or parts of this software is strictly ** forbidden. ** ** The "appropriate copyright message" mentioned in section 2c of the GPLv2 ** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com" ** ** Commercial non-GPL licensing of this software is possible. ** For more info contact Nero AG through [email protected]. ** ** $Id: ms.c,v 1.21 2007/11/01 12:33:32 menno Exp $ **/ #include "common.h" #include "structs.h" #include "syntax.h" #include "ms.h" #include "is.h" #include "pns.h" void ms_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec, uint16_t frame_len) { uint8_t g, b, sfb; uint8_t group = 0; uint16_t nshort = frame_len/8; uint16_t i, k; real_t tmp; if (ics->ms_mask_present >= 1) { for (g = 0; g < ics->num_window_groups; g++) { for (b = 0; b < ics->window_group_length[g]; b++) { for (sfb = 0; sfb < ics->max_sfb; sfb++) { /* If intensity stereo coding or noise substitution is on for a particular scalefactor band, no M/S stereo decoding is carried out. */ if ((ics->ms_used[g][sfb] || ics->ms_mask_present == 2) && !is_intensity(icsr, g, sfb) && !is_noise(ics, g, sfb)) { for (i = ics->swb_offset[sfb]; i < min(ics->swb_offset[sfb+1], ics->swb_offset_max); i++) { k = (group*nshort) + i; tmp = l_spec[k] - r_spec[k]; l_spec[k] = l_spec[k] + r_spec[k]; r_spec[k] = tmp; } } } group++; } } } }