Repository navigation
Expand file tree
/
Copy pathmsis.c
More file actions
299 lines (262 loc) · 7.27 KB
/
Copy pathmsis.c
File metadata and controls
299 lines (262 loc) · 7.27 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/*____________________________________________________________________________
FreeAmp - The Free MP3 Player
MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology
Corp. http://www.xingtech.com
Portions Copyright (C) 1998-1999 EMusic.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., 675 Mass Ave, Cambridge, MA 02139, USA.
____________________________________________________________________________*/
/**** msis.c ***************************************************
Layer III
antialias, ms and is stereo precessing
**** is_process assumes never switch
from short to long in is region *****
is_process does ms or stereo in "forbidded sf regions"
//ms_mode = 0
lr[0][i][0] = 1.0f;
lr[0][i][1] = 0.0f;
// ms_mode = 1, in is bands is routine does ms processing
lr[1][i][0] = 1.0f;
lr[1][i][1] = 1.0f;
******************************************************************/
#include <float.h>
#include <math.h>
#include <string.h>
#include "L3.h"
#include "mhead.h"
/* The functions are different than their prototypes, by design */
typedef float ARRAY2[2];
typedef float ARRAY8_2[8][2];
/* nBand[0] = long, nBand[1] = short */
/* intensity stereo */
/* if ms mode quant pre-scales all values by 1.0/sqrt(2.0) ms_mode in table
compensates */
/* intensity stereo MPEG2 */
/* lr2[intensity_scale][ms_mode][sflen_offset+sf][left/right] */
typedef float ARRAY2_64_2[2][64][2];
typedef float ARRAY64_2[64][2];
#ifdef ASM_X86
extern void antialias_asm(float x[], int n, float *t);
#endif /* ASM_X86 */
/*===============================================================*/
ARRAY2 *alias_init_addr(MPEG *m)
{
return m->cupl.csa;
}
/*-----------------------------------------------------------*/
ARRAY8_2 *msis_init_addr(MPEG *m)
{
/*-------
pi = 4.0*atan(1.0);
t = pi/12.0;
for(i=0;i<7;i++) {
s = sin(i*t);
c = cos(i*t);
// ms_mode = 0
m->cupl.lr[0][i][0] = (float)(s/(s+c));
m->cupl.lr[0][i][1] = (float)(c/(s+c));
// ms_mode = 1
m->cupl.lr[1][i][0] = (float)(sqrt(2.0)*(s/(s+c)));
m->cupl.lr[1][i][1] = (float)(sqrt(2.0)*(c/(s+c)));
}
//sf = 7
//ms_mode = 0
m->cupl.lr[0][i][0] = 1.0f;
m->cupl.lr[0][i][1] = 0.0f;
// ms_mode = 1, in is bands is routine does ms processing
m->cupl.lr[1][i][0] = 1.0f;
m->cupl.lr[1][i][1] = 1.0f;
------------*/
return m->cupl.lr;
}
/*-------------------------------------------------------------*/
ARRAY2_64_2 *msis_init_addr_MPEG2(MPEG *m)
{
return m->cupl.lr2;
}
/*===============================================================*/
void antialias(MPEG *m, float x[], int n)
{
#ifdef ASM_X86
antialias_asm(x, n, (float *)m->cupl.csa);
#else
int i, k;
float a, b;
for (k = 0; k < n; k++)
{
for (i = 0; i < 8; i++)
{
a = x[17 - i];
b = x[18 + i];
x[17 - i] = a * m->cupl.csa[i][0] - b * m->cupl.csa[i][1];
x[18 + i] = b * m->cupl.csa[i][0] + a * m->cupl.csa[i][1];
}
x += 18;
}
#endif
}
/*===============================================================*/
void ms_process(float x[][1152], int n) /* sum-difference stereo */
{
int i;
float xl, xr;
/*-- note: sqrt(2) done scaling by dequant ---*/
for (i = 0; i < n; i++)
{
xl = x[0][i] + x[1][i];
xr = x[0][i] - x[1][i];
x[0][i] = xl;
x[1][i] = xr;
}
return;
}
/*===============================================================*/
void is_process_MPEG1(MPEG *vm, float x[][1152], /* intensity stereo */
SCALEFACT * sf,
CB_INFO cb_info[2], /* [ch] */
int nsamp, int ms_mode)
{
int i, j, n, cb, w;
float fl, fr;
int m;
int isf;
float fls[3], frs[3];
int cb0;
cb0 = cb_info[1].cbmax; /* start at end of right */
i = vm->cupl.sfBandIndex[cb_info[1].cbtype][cb0];
cb0++;
m = nsamp - i; /* process to len of left */
if (cb_info[1].cbtype)
goto short_blocks;
/*------------------------*/
/* long_blocks: */
for (cb = cb0; cb < 21; cb++)
{
isf = sf->l[cb];
n = vm->cupl.nBand[0][cb];
fl = vm->cupl.lr[ms_mode][isf][0];
fr = vm->cupl.lr[ms_mode][isf][1];
for (j = 0; j < n; j++, i++)
{
if (--m < 0)
goto exit;
x[1][i] = fr * x[0][i];
x[0][i] = fl * x[0][i];
}
}
return;
/*------------------------*/
short_blocks:
for (cb = cb0; cb < 12; cb++)
{
for (w = 0; w < 3; w++)
{
isf = sf->s[w][cb];
fls[w] = vm->cupl.lr[ms_mode][isf][0];
frs[w] = vm->cupl.lr[ms_mode][isf][1];
}
n = vm->cupl.nBand[1][cb];
for (j = 0; j < n; j++)
{
m -= 3;
if (m < 0)
goto exit;
x[1][i] = frs[0] * x[0][i];
x[0][i] = fls[0] * x[0][i];
x[1][1 + i] = frs[1] * x[0][1 + i];
x[0][1 + i] = fls[1] * x[0][1 + i];
x[1][2 + i] = frs[2] * x[0][2 + i];
x[0][2 + i] = fls[2] * x[0][2 + i];
i += 3;
}
}
exit:
return;
}
/*===============================================================*/
void is_process_MPEG2(MPEG *vm, float x[][1152], /* intensity stereo */
SCALEFACT * sf,
CB_INFO cb_info[2], /* [ch] */
IS_SF_INFO * is_sf_info,
int nsamp, int ms_mode)
{
int i, j, k, n, cb, w;
float fl, fr;
int m;
int isf;
int il[21];
int tmp;
int r;
ARRAY2 *lr;
int cb0, cb1;
memset(il, 0, sizeof(il));
lr = vm->cupl.lr2[is_sf_info->intensity_scale][ms_mode];
if (cb_info[1].cbtype)
goto short_blocks;
/*------------------------*/
/* long_blocks: */
cb0 = cb_info[1].cbmax; /* start at end of right */
i = vm->cupl.sfBandIndex[0][cb0];
m = nsamp - i; /* process to len of left */
/* gen sf info */
for (k = r = 0; r < 3; r++)
{
tmp = (1 << is_sf_info->slen[r]) - 1;
for (j = 0; j < is_sf_info->nr[r]; j++, k++)
il[k] = tmp;
}
for (cb = cb0 + 1; cb < 21; cb++)
{
isf = il[cb] + sf->l[cb];
fl = lr[isf][0];
fr = lr[isf][1];
n = vm->cupl.nBand[0][cb];
for (j = 0; j < n; j++, i++)
{
if (--m < 0)
goto exit;
x[1][i] = fr * x[0][i];
x[0][i] = fl * x[0][i];
}
}
return;
/*------------------------*/
short_blocks:
for (k = r = 0; r < 3; r++)
{
tmp = (1 << is_sf_info->slen[r]) - 1;
for (j = 0; j < is_sf_info->nr[r]; j++, k++)
il[k] = tmp;
}
for (w = 0; w < 3; w++)
{
cb0 = cb_info[1].cbmax_s[w]; /* start at end of right */
i = vm->cupl.sfBandIndex[1][cb0] + w;
cb1 = cb_info[0].cbmax_s[w]; /* process to end of left */
for (cb = cb0 + 1; cb <= cb1; cb++)
{
isf = il[cb] + sf->s[w][cb];
fl = lr[isf][0];
fr = lr[isf][1];
n = vm->cupl.nBand[1][cb];
for (j = 0; j < n; j++)
{
x[1][i] = fr * x[0][i];
x[0][i] = fl * x[0][i];
i += 3;
}
}
}
exit:
return;
}
/*===============================================================*/