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
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
|
/*
* coeff.c
*
* Copyright (C) Aaron Holtzman - May 1999
*
* This file is part of ac3dec, a free Dolby AC-3 stream decoder.
*
* ac3dec 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, or (at your option)
* any later version.
*
* ac3dec 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 GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include "ac3.h"
#include "ac3_internal.h"
#include "bitstream.h"
#include "dither.h"
#include "coeff.h"
//
//Lookup tables of 0.15 two's complement quantization values
//
#define Q0 ((-2 << 15) / 3.0)
#define Q1 (0)
#define Q2 ((2 << 15) / 3.0)
static const float q_1_0[ 32 ] =
{
Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,
0,0,0,0,0
};
static const float q_1_1[ 32 ] =
{
Q0,Q0,Q0,Q1,Q1,Q1,Q2,Q2,Q2,
Q0,Q0,Q0,Q1,Q1,Q1,Q2,Q2,Q2,
Q0,Q0,Q0,Q1,Q1,Q1,Q2,Q2,Q2,
0,0,0,0,0
};
static const float q_1_2[ 32 ] =
{
Q0,Q1,Q2,Q0,Q1,Q2,Q0,Q1,Q2,
Q0,Q1,Q2,Q0,Q1,Q2,Q0,Q1,Q2,
Q0,Q1,Q2,Q0,Q1,Q2,Q0,Q1,Q2,
0,0,0,0,0
};
#undef Q0
#undef Q1
#undef Q2
#define Q0 ((-4 << 15) / 5.0)
#define Q1 ((-2 << 15) / 5.0)
#define Q2 (0)
#define Q3 ((2 << 15) / 5.0)
#define Q4 ((4 << 15) / 5.0)
static const float q_2_0[ 128 ] =
{
Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,
Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,
Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,
Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,
Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,
Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,
Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,
0,0,0
};
static const float q_2_1[ 128 ] =
{
Q0,Q0,Q0,Q0,Q0,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q2,Q2,Q2,Q2,Q2,
Q3,Q3,Q3,Q3,Q3,Q4,Q4,Q4,Q4,Q4,
Q0,Q0,Q0,Q0,Q0,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q2,Q2,Q2,Q2,Q2,
Q3,Q3,Q3,Q3,Q3,Q4,Q4,Q4,Q4,Q4,
Q0,Q0,Q0,Q0,Q0,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,0,0,0
};
static const float q_2_2[ 128 ] =
{
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,0,0,0
};
#undef Q0
#undef Q1
#undef Q2
#undef Q3
#undef Q4
static const float q_3[7] =
{
(-6 << 15)/7.0, (-4 << 15)/7.0, (-2 << 15)/7.0, 0.0,
( 2 << 15)/7.0, ( 4 << 15)/7.0, ( 6 << 15)/7.0
};
#define Q0 ((-10 << 15) / 11.0)
#define Q1 ((-8 << 15) / 11.0)
#define Q2 ((-6 << 15) / 11.0)
#define Q3 ((-4 << 15) / 11.0)
#define Q4 ((-2 << 15) / 11.0)
#define Q5 (0)
#define Q6 ((2 << 15) / 11.0)
#define Q7 ((4 << 15) / 11.0)
#define Q8 ((6 << 15) / 11.0)
#define Q9 ((8 << 15) / 11.0)
#define QA ((10 << 15) / 11.0)
static const float q_4_0[ 128 ] =
{
Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0,
Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1,
Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2,
Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3,
Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4,
Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5,
Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6,
Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7,
Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8,
Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9,
QA, QA, QA, QA, QA, QA, QA, QA, QA, QA, QA,
0, 0, 0, 0, 0, 0, 0
};
static const float q_4_1[ 128 ] =
{
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
0, 0, 0, 0, 0, 0, 0
};
#undef Q0
#undef Q1
#undef Q2
#undef Q3
#undef Q4
#undef Q5
#undef Q6
#undef Q7
#undef Q8
#undef Q9
#undef QA
static const float q_5[15] =
{
(-14 << 15)/15.0,(-12 << 15)/15.0,(-10 << 15)/15.0,
( -8 << 15)/15.0,( -6 << 15)/15.0,( -4 << 15)/15.0,
( -2 << 15)/15.0, 0.0 ,( 2 << 15)/15.0,
( 4 << 15)/15.0,( 6 << 15)/15.0,( 8 << 15)/15.0,
( 10 << 15)/15.0,( 12 << 15)/15.0,( 14 << 15)/15.0
};
//
// Scale factors for convert_to_float
//
static const uint32_t u32_scale_factors[25] =
{
0x38000000, //2 ^ -(0 + 15)
0x37800000, //2 ^ -(1 + 15)
0x37000000, //2 ^ -(2 + 15)
0x36800000, //2 ^ -(3 + 15)
0x36000000, //2 ^ -(4 + 15)
0x35800000, //2 ^ -(5 + 15)
0x35000000, //2 ^ -(6 + 15)
0x34800000, //2 ^ -(7 + 15)
0x34000000, //2 ^ -(8 + 15)
0x33800000, //2 ^ -(9 + 15)
0x33000000, //2 ^ -(10 + 15)
0x32800000, //2 ^ -(11 + 15)
0x32000000, //2 ^ -(12 + 15)
0x31800000, //2 ^ -(13 + 15)
0x31000000, //2 ^ -(14 + 15)
0x30800000, //2 ^ -(15 + 15)
0x30000000, //2 ^ -(16 + 15)
0x2f800000, //2 ^ -(17 + 15)
0x2f000000, //2 ^ -(18 + 15)
0x2e800000, //2 ^ -(19 + 15)
0x2e000000, //2 ^ -(20 + 15)
0x2d800000, //2 ^ -(21 + 15)
0x2d000000, //2 ^ -(22 + 15)
0x2c800000, //2 ^ -(23 + 15)
0x2c000000 //2 ^ -(24 + 15)
};
static float *scale_factor = (float*)u32_scale_factors;
//These store the persistent state of the packed mantissas
static float q_1[2];
static float q_2[2];
static float q_4[1];
static int32_t q_1_pointer;
static int32_t q_2_pointer;
static int32_t q_4_pointer;
static float __inline__
coeff_get_float(uint16_t bap, uint16_t dithflag, uint16_t exp);
//Conversion from bap to number of bits in the mantissas
//zeros account for cases 0,1,2,4 which are special cased
static uint16_t qnttztab[16] =
{
0, 0, 0, 3,
0, 4, 5, 6,
7, 8, 9, 10,
11, 12, 14, 16
};
static void coeff_reset(void);
static float coeff_get_float(uint16_t bap, uint16_t dithflag, uint16_t exp);
static void coeff_uncouple_ch(float samples[],bsi_t *bsi,audblk_t *audblk,uint32_t ch);
void coeff_unpack(bsi_t *bsi, audblk_t *audblk, stream_samples_t samples)
{
uint16_t i,j;
uint32_t done_cpl = 0;
coeff_reset();
for(i=0; i< bsi->nfchans; i++) {
for(j=0; j < audblk->endmant[i]; j++)
samples[i][j] = coeff_get_float(audblk->fbw_bap[i][j], audblk->dithflag[i], audblk->fbw_exp[i][j]);
if(audblk->cplinu && audblk->chincpl[i] && !(done_cpl)) {
// ncplmant is equal to 12 * ncplsubnd
// Don't dither coupling channel until channel
// separation so that interchannel noise is uncorrelated
for(j=audblk->cplstrtmant; j < audblk->cplendmant; j++)
audblk->cpl_flt[j] = coeff_get_float(audblk->cpl_bap[j],0, audblk->cpl_exp[j]);
done_cpl = 1;
}
}
//uncouple the channel if necessary
if(audblk->cplinu) {
for(i=0; i< bsi->nfchans; i++) {
if(audblk->chincpl[i])
coeff_uncouple_ch(samples[i],bsi,audblk,i);
}
}
if(bsi->lfeon) {
// There are always 7 mantissas for lfe, no dither for lfe
for(j=0; j < 7 ; j++)
samples[5][j] = coeff_get_float(audblk->lfe_bap[j], 0, audblk->lfe_exp[j]);
}
}
/**
* Fetch a float from the bitstream
**/
static float inline coeff_get_float (uint16_t bap, uint16_t dithflag, uint16_t exp)
{
uint16_t dummy = 0;
//If the bap is 0-5 then we have special cases to take care of
switch(bap) {
case 0:
if(dithflag)
return (dither_gen() * scale_factor[exp]);
return 0.0;
case 1:
if (q_1_pointer >= 0)
return(q_1[q_1_pointer--] * scale_factor[exp]);
if ((dummy = bitstream_get (5)) > 26)
goto error;
q_1[1] = q_1_1[dummy];
q_1[0] = q_1_2[dummy];
q_1_pointer = 1;
return (q_1_0[dummy] * scale_factor[exp]);
case 2:
if(q_2_pointer >= 0)
return (q_2[q_2_pointer--] * scale_factor[exp]);
if ((dummy = bitstream_get (7)) > 124)
goto error;
q_2[1] = q_2_1[dummy];
q_2[0] = q_2_2[dummy];
q_2_pointer = 1;
return (q_2_0[dummy] * scale_factor[exp]);
case 3:
if ((dummy = bitstream_get (3)) > 6)
goto error;
return (q_3[dummy] * scale_factor[exp]);
case 4:
if(q_4_pointer >= 0)
return (q_4[q_4_pointer--] * scale_factor[exp]);
if ((dummy = bitstream_get (7)) > 120)
goto error;
q_4[0] = q_4_1[dummy];
q_4_pointer = 0;
return (q_4_0[dummy] * scale_factor[exp]);
case 5:
if ((dummy = bitstream_get (4)) > 14)
goto error;
return (q_5[dummy] * scale_factor[exp]);
default:
dummy = bitstream_get(qnttztab[bap]);
dummy <<= 16 - qnttztab[bap];
return ((int16_t)dummy * scale_factor[exp]);
}
error:
#ifdef DEBUG
fprintf(stderr,"** Invalid mantissa - skipping frame **\n");
#endif
HANDLE_ERROR();
}
/**
* Reset the mantissa state
**/
static void coeff_reset(void)
{
q_1_pointer = q_2_pointer = q_4_pointer = -1;
}
/**
* Uncouple the coupling channel into a fbw channel
**/
static void coeff_uncouple_ch (float samples[],bsi_t *bsi,audblk_t *audblk,uint32_t ch)
{
uint32_t bnd = 0;
uint32_t sub_bnd = 0;
uint32_t i,j;
float cpl_coord = 1.0;
uint32_t cpl_exp_tmp;
uint32_t cpl_mant_tmp;
for (i=audblk->cplstrtmant;i<audblk->cplendmant;) {
if (!audblk->cplbndstrc[sub_bnd++]) {
cpl_exp_tmp = audblk->cplcoexp[ch][bnd] + 3 * audblk->mstrcplco[ch];
if (audblk->cplcoexp[ch][bnd] == 15)
cpl_mant_tmp = (audblk->cplcomant[ch][bnd]) << 11;
else
cpl_mant_tmp = ((0x10) | audblk->cplcomant[ch][bnd]) << 10;
cpl_coord = (cpl_mant_tmp * scale_factor[cpl_exp_tmp]) * 8.0f;
//Invert the phase for the right channel if necessary
if(bsi->acmod == 0x2 && audblk->phsflginu && ch == 1 && audblk->phsflg[bnd])
cpl_coord *= -1;
bnd++;
}
for(j=0;j < 12; j++) {
// Get new dither values for each channel if necessary,
// so the channels are uncorrelated
if(audblk->dithflag[ch] && !audblk->cpl_bap[i])
samples[i] = cpl_coord * (dither_gen() * scale_factor[audblk->cpl_exp[i]]);
else
samples[i] = cpl_coord * audblk->cpl_flt[i];
i++;
}
}
}
|
