mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
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78 lines
2.8 KiB
C++
78 lines
2.8 KiB
C++
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/*
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** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
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** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
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**
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** This program is free software; you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation; either version 2 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program; if not, write to the Free Software
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** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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**
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** Any non-GPL usage of this software or parts of this software is strictly
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** forbidden.
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**
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** The "appropriate copyright message" mentioned in section 2c of the GPLv2
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** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
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**
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** Commercial non-GPL licensing of this software is possible.
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** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
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**
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** $Id: ms.c,v 1.21 2007/11/01 12:33:32 menno Exp $
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**/
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#include "common.h"
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#include "structs.h"
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#include "syntax.h"
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#include "ms.h"
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#include "is.h"
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#include "pns.h"
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void ms_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec,
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uint16_t frame_len)
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{
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uint8_t g, b, sfb;
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uint8_t group = 0;
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uint16_t nshort = frame_len/8;
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uint16_t i, k;
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real_t tmp;
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if (ics->ms_mask_present >= 1)
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{
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for (g = 0; g < ics->num_window_groups; g++)
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{
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for (b = 0; b < ics->window_group_length[g]; b++)
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{
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for (sfb = 0; sfb < ics->max_sfb; sfb++)
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{
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/* If intensity stereo coding or noise substitution is on
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for a particular scalefactor band, no M/S stereo decoding
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is carried out.
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*/
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if ((ics->ms_used[g][sfb] || ics->ms_mask_present == 2) &&
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!is_intensity(icsr, g, sfb) && !is_noise(ics, g, sfb))
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{
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for (i = ics->swb_offset[sfb]; i < min(ics->swb_offset[sfb+1], ics->swb_offset_max); i++)
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{
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k = (group*nshort) + i;
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tmp = l_spec[k] - r_spec[k];
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l_spec[k] = l_spec[k] + r_spec[k];
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r_spec[k] = tmp;
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}
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}
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}
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group++;
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}
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}
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}
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}
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