1 /*****************************************************************************
3 *****************************************************************************
4 * Copyright (C) 1999, 2000 VideoLAN
5 * $Id: ac3_imdct.c,v 1.1 2001/11/13 12:09:17 henri 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() */
41 #include "stream_control.h"
42 #include "input_ext-dec.h"
44 #include "ac3_imdct.h"
45 #include "ac3_downmix.h"
46 #include "ac3_decoder.h"
49 # define M_PI 3.14159265358979323846
52 void imdct_init(imdct_t * p_imdct)
55 float scale = 181.019;
57 p_imdct->pf_imdct_init( p_imdct );
59 /* More twiddle factors to turn IFFT into IMDCT */
60 for (i=0; i < 64; i++) {
61 p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
62 p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
66 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
70 float *center=NULL, *left, *right, *left_sur, *right_sur;
71 float *delay_left, *delay_right;
72 float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
73 float right_tmp, left_tmp;
74 void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
76 /* test if dm in frequency is doable */
77 if (!(doable = p_ac3dec->audblk.blksw[0]))
79 do_imdct = p_ac3dec->imdct->pf_imdct_512;
83 do_imdct = p_ac3dec->imdct->pf_imdct_256;
86 /* downmix in the frequency domain if all the channels
87 * use the same imdct */
88 for (i=0; i < p_ac3dec->bsi.nfchans; i++)
90 if (doable != p_ac3dec->audblk.blksw[i])
99 /* dowmix first and imdct */
100 switch(p_ac3dec->bsi.acmod)
103 p_ac3dec->downmix.pf_downmix_3f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
106 p_ac3dec->downmix.pf_downmix_2f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
109 p_ac3dec->downmix.pf_downmix_3f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
112 p_ac3dec->downmix.pf_downmix_2f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
115 p_ac3dec->downmix.pf_downmix_3f_0r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
120 // if (p_ac3dec->bsi.acmod == 1)
121 center = p_ac3dec->samples;
122 // else if (p_ac3dec->bsi.acmod == 0)
123 // center = samples[ac3_config.dual_mono_ch_sel];
124 do_imdct(p_ac3dec->imdct, center, p_ac3dec->imdct->delay); /* no downmix*/
126 p_ac3dec->downmix.pf_stream_sample_1ch_to_s16 (buffer, center);
132 do_imdct (p_ac3dec->imdct, p_ac3dec->samples, p_ac3dec->imdct->delay);
133 do_imdct (p_ac3dec->imdct, p_ac3dec->samples+256, p_ac3dec->imdct->delay+256);
134 p_ac3dec->downmix.pf_stream_sample_2ch_to_s16(buffer, p_ac3dec->samples, p_ac3dec->samples+256);
137 /* imdct and then downmix
138 * delay and samples should be saved and mixed
139 * fprintf(stderr, "time domain downmix\n"); */
140 for (i=0; i<p_ac3dec->bsi.nfchans; i++)
142 if (p_ac3dec->audblk.blksw[i])
143 /* There is only a C function */
144 p_ac3dec->imdct->pf_imdct_256_nol (p_ac3dec->imdct, p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i);
146 p_ac3dec->imdct->pf_imdct_512_nol (p_ac3dec->imdct, p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i);
149 /* mix the sample, overlap */
150 switch(p_ac3dec->bsi.acmod)
153 left = p_ac3dec->samples;
154 center = p_ac3dec->samples+256;
155 right = p_ac3dec->samples+2*256;
156 left_sur = p_ac3dec->samples+3*256;
157 right_sur = p_ac3dec->samples+4*256;
158 delay_left = p_ac3dec->imdct->delay;
159 delay_right = p_ac3dec->imdct->delay+256;
160 delay1_left = p_ac3dec->imdct->delay1;
161 delay1_center = p_ac3dec->imdct->delay1+256;
162 delay1_right = p_ac3dec->imdct->delay1+2*256;
163 delay1_sl = p_ac3dec->imdct->delay1+3*256;
164 delay1_sr = p_ac3dec->imdct->delay1+4*256;
166 for (i = 0; i < 256; i++) {
167 left_tmp = p_ac3dec->dm_par.unit * *left++ + p_ac3dec->dm_par.clev * *center + p_ac3dec->dm_par.slev * *left_sur++;
168 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
169 *buffer++ = (s16)(left_tmp + *delay_left);
170 *buffer++ = (s16)(right_tmp + *delay_right);
171 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.clev * *delay1_center + p_ac3dec->dm_par.slev * *delay1_sl++;
172 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
176 left = p_ac3dec->samples;
177 right = p_ac3dec->samples+256;
178 left_sur = p_ac3dec->samples+2*256;
179 right_sur = p_ac3dec->samples+3*256;
180 delay_left = p_ac3dec->imdct->delay;
181 delay_right = p_ac3dec->imdct->delay+256;
182 delay1_left = p_ac3dec->imdct->delay1;
183 delay1_right = p_ac3dec->imdct->delay1+256;
184 delay1_sl = p_ac3dec->imdct->delay1+2*256;
185 delay1_sr = p_ac3dec->imdct->delay1+3*256;
187 for (i = 0; i < 256; i++) {
188 left_tmp = p_ac3dec->dm_par.unit * *left++ + p_ac3dec->dm_par.slev * *left_sur++;
189 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
190 *buffer++ = (s16)(left_tmp + *delay_left);
191 *buffer++ = (s16)(right_tmp + *delay_right);
192 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl++;
193 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
197 left = p_ac3dec->samples;
198 center = p_ac3dec->samples+256;
199 right = p_ac3dec->samples+2*256;
200 right_sur = p_ac3dec->samples+3*256;
201 delay_left = p_ac3dec->imdct->delay;
202 delay_right = p_ac3dec->imdct->delay+256;
203 delay1_left = p_ac3dec->imdct->delay1;
204 delay1_center = p_ac3dec->imdct->delay1+256;
205 delay1_right = p_ac3dec->imdct->delay1+2*256;
206 delay1_sl = p_ac3dec->imdct->delay1+3*256;
208 for (i = 0; i < 256; i++) {
209 left_tmp = p_ac3dec->dm_par.unit * *left++ + p_ac3dec->dm_par.clev * *center - p_ac3dec->dm_par.slev * *right_sur;
210 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
211 *buffer++ = (s16)(left_tmp + *delay_left);
212 *buffer++ = (s16)(right_tmp + *delay_right);
213 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.clev * *delay1_center + p_ac3dec->dm_par.slev * *delay1_sl;
214 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
218 left = p_ac3dec->samples;
219 right = p_ac3dec->samples+256;
220 right_sur = p_ac3dec->samples+2*256;
221 delay_left = p_ac3dec->imdct->delay;
222 delay_right = p_ac3dec->imdct->delay+256;
223 delay1_left = p_ac3dec->imdct->delay1;
224 delay1_right = p_ac3dec->imdct->delay1+256;
225 delay1_sl = p_ac3dec->imdct->delay1+2*256;
227 for (i = 0; i < 256; i++) {
228 left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
229 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
230 *buffer++ = (s16)(left_tmp + *delay_left);
231 *buffer++ = (s16)(right_tmp + *delay_right);
232 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
233 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
237 left = p_ac3dec->samples;
238 center = p_ac3dec->samples+256;
239 right = p_ac3dec->samples+2*256;
240 delay_left = p_ac3dec->imdct->delay;
241 delay_right = p_ac3dec->imdct->delay+256;
242 delay1_left = p_ac3dec->imdct->delay1;
243 delay1_center = p_ac3dec->imdct->delay1+256;
244 delay1_right = p_ac3dec->imdct->delay1+2*256;
246 for (i = 0; i < 256; i++) {
247 left_tmp = p_ac3dec->dm_par.unit * *left++ + p_ac3dec->dm_par.clev * *center;
248 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
249 *buffer++ = (s16)(left_tmp + *delay_left);
250 *buffer++ = (s16)(right_tmp + *delay_right);
251 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.clev * *delay1_center;
252 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
255 case 2: /* copy to output */
256 for (i = 0; i < 256; i++) {
257 *buffer++ = (s16) *(p_ac3dec->samples+i);
258 *buffer++ = (s16) *(p_ac3dec->samples+256+i);