2 * mad - MPEG audio decoder
3 * Copyright (C) 2000-2003 Robert Leslie
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
34 * DESCRIPTION: perform attenuation or amplification
36 void gain_filter(mad_fixed_t gain
, struct mad_frame
*frame
)
38 if (gain
!= MAD_F_ONE
) {
39 unsigned int nch
, ch
, ns
, s
, sb
;
41 nch
= MAD_NCHANNELS(&frame
->header
);
42 ns
= MAD_NSBSAMPLES(&frame
->header
);
44 for (ch
= 0; ch
< nch
; ++ch
) {
45 for (s
= 0; s
< ns
; ++s
) {
46 for (sb
= 0; sb
< 32; ++sb
) {
47 frame
->sbsample
[ch
][s
][sb
] =
48 mad_f_mul(frame
->sbsample
[ch
][s
][sb
], gain
);