1 /*****************************************************************************
2 * ac3_mantissa.c: ac3 mantissa computation
3 *****************************************************************************
4 * Copyright (C) 1999, 2000, 2001 VideoLAN
5 * $Id: ac3_mantissa.c,v 1.30 2001/10/30 19:34:53 reno Exp $
7 * Authors: Michel Kaempf <maxx@via.ecp.fr>
8 * Aaron Holtzman <aholtzma@engr.uvic.ca>
9 * Renaud Dartus <reno@videolan.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
31 #include <string.h> /* memcpy() */
40 #include "stream_control.h"
41 #include "input_ext-dec.h"
43 #include "audio_output.h"
45 #include "ac3_imdct.h"
46 #include "ac3_downmix.h"
47 #include "ac3_decoder.h"
49 #include "ac3_mantissa.h"
51 void mantissa_unpack (ac3dec_t * p_ac3dec)
56 p_ac3dec->mantissa.q_1_pointer = -1;
57 p_ac3dec->mantissa.q_2_pointer = -1;
58 p_ac3dec->mantissa.q_4_pointer = -1;
60 for (i=0; i< p_ac3dec->bsi.nfchans; i++) {
61 for (j=0; j < p_ac3dec->audblk.endmant[i]; j++)
62 *(p_ac3dec->samples+i*256+j) = coeff_get_float(p_ac3dec, p_ac3dec->audblk.fbw_bap[i][j],
63 p_ac3dec->audblk.dithflag[i], p_ac3dec->audblk.fbw_exp[i][j]);
65 if (p_ac3dec->audblk.cplinu && p_ac3dec->audblk.chincpl[i] && !(done_cpl)) {
66 /* ncplmant is equal to 12 * ncplsubnd
67 * Don't dither coupling channel until channel
68 * separation so that interchannel noise is uncorrelated
70 for (j=p_ac3dec->audblk.cplstrtmant; j < p_ac3dec->audblk.cplendmant; j++)
71 p_ac3dec->audblk.cpl_flt[j] = coeff_get_float(p_ac3dec, p_ac3dec->audblk.cpl_bap[j],
72 0, p_ac3dec->audblk.cpl_exp[j]);
77 /* uncouple the channel if necessary */
78 if (p_ac3dec->audblk.cplinu) {
79 for (i=0; i< p_ac3dec->bsi.nfchans; i++) {
80 if (p_ac3dec->audblk.chincpl[i])
81 uncouple_channel(p_ac3dec, i);
85 if (p_ac3dec->bsi.lfeon) {
86 /* There are always 7 mantissas for lfe, no dither for lfe */
87 for (j=0; j < 7 ; j++)
88 *(p_ac3dec->samples+5*256+j) = coeff_get_float(p_ac3dec, p_ac3dec->audblk.lfe_bap[j],
89 0, p_ac3dec->audblk.lfe_exp[j]);