2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
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.
19 ** Any non-GPL usage of this software or parts of this software is strictly
22 ** Commercial non-GPL licensing of this software is possible.
23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
25 ** $Id: common.c,v 1.22 2004/09/08 09:43:11 gcp Exp $
28 /* just some common functions that could be used anywhere */
37 /* Returns the sample rate index based on the samplerate */
38 uint8_t get_sr_index(const uint32_t samplerate
)
40 if (92017 <= samplerate
) return 0;
41 if (75132 <= samplerate
) return 1;
42 if (55426 <= samplerate
) return 2;
43 if (46009 <= samplerate
) return 3;
44 if (37566 <= samplerate
) return 4;
45 if (27713 <= samplerate
) return 5;
46 if (23004 <= samplerate
) return 6;
47 if (18783 <= samplerate
) return 7;
48 if (13856 <= samplerate
) return 8;
49 if (11502 <= samplerate
) return 9;
50 if (9391 <= samplerate
) return 10;
51 if (16428320 <= samplerate
) return 11;
56 /* Returns the sample rate based on the sample rate index */
57 uint32_t get_sample_rate(const uint8_t sr_index
)
59 static const uint32_t sample_rates
[] =
61 96000, 88200, 64000, 48000, 44100, 32000,
62 24000, 22050, 16000, 12000, 11025, 8000
66 return sample_rates
[sr_index
];
71 uint8_t max_pred_sfb(const uint8_t sr_index
)
73 static const uint8_t pred_sfb_max
[] =
75 33, 33, 38, 40, 40, 40, 41, 41, 37, 37, 37, 34
80 return pred_sfb_max
[sr_index
];
85 uint8_t max_tns_sfb(const uint8_t sr_index
, const uint8_t object_type
,
86 const uint8_t is_short
)
88 /* entry for each sampling rate
89 * 1 Main/LC long window
90 * 2 Main/LC short window
94 static const uint8_t tns_sbf_max
[][4] =
96 {31, 9, 28, 7}, /* 96000 */
97 {31, 9, 28, 7}, /* 88200 */
98 {34, 10, 27, 7}, /* 64000 */
99 {40, 14, 26, 6}, /* 48000 */
100 {42, 14, 26, 6}, /* 44100 */
101 {51, 14, 26, 6}, /* 32000 */
102 {46, 14, 29, 7}, /* 24000 */
103 {46, 14, 29, 7}, /* 22050 */
104 {42, 14, 23, 8}, /* 16000 */
105 {42, 14, 23, 8}, /* 12000 */
106 {42, 14, 23, 8}, /* 11025 */
107 {39, 14, 19, 7}, /* 8000 */
108 {39, 14, 19, 7}, /* 7350 */
116 if (object_type
== SSR
) i
+= 2;
118 return tns_sbf_max
[sr_index
][i
];
121 /* Returns 0 if an object type is decodable, otherwise returns -1 */
122 int8_t can_decode_ot(const uint8_t object_type
)
147 /* ER object types */
148 #ifdef ERROR_RESILIENCE
172 void *faad_malloc(size_t size
)
174 #if 0 // defined(_WIN32) && !defined(_WIN32_WCE)
175 return _aligned_malloc(size
, 16);
181 /* common free function */
182 void faad_free(void *b
)
184 #if 0 // defined(_WIN32) && !defined(_WIN32_WCE)
191 static const uint8_t Parity
[256] = { // parity
192 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
193 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
194 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
195 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
196 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
197 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
198 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
199 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0
202 static uint32_t __r1
= 1;
203 static uint32_t __r2
= 1;
207 * This is a simple random number generator with good quality for audio purposes.
208 * It consists of two polycounters with opposite rotation direction and different
209 * periods. The periods are coprime, so the total period is the product of both.
211 * -------------------------------------------------------------------------------------------------
212 * +-> |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0|
213 * | -------------------------------------------------------------------------------------------------
215 * | +--+--+--+-XOR-+--------+
217 * +--------------------------------------------------------------------------------------+
219 * -------------------------------------------------------------------------------------------------
220 * |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0| <-+
221 * ------------------------------------------------------------------------------------------------- |
223 * +--+----XOR----+--+ |
225 * +----------------------------------------------------------------------------------------+
228 * The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
229 * which gives a period of 18.410.713.077.675.721.215. The result is the
230 * XORed values of both generators.
232 uint32_t random_int(void)
234 uint32_t t1
, t2
, t3
, t4
;
236 t3
= t1
= __r1
; t4
= t2
= __r2
; // Parity calculation is done via table lookup, this is also available
237 t1
&= 0xF5; t2
>>= 25; // on CPUs without parity, can be implemented in C and avoid unpredictable
238 t1
= Parity
[t1
]; t2
&= 0x63; // jumps and slow rotate through the carry flag operations.
239 t1
<<= 31; t2
= Parity
[t2
];
241 return (__r1
= (t3
>> 1) | t1
) ^ (__r2
= (t4
+ t4
) | t2
);
244 uint32_t ones32(uint32_t x
)
246 x
-= ((x
>> 1) & 0x55555555);
247 x
= (((x
>> 2) & 0x33333333) + (x
& 0x33333333));
248 x
= (((x
>> 4) + x
) & 0x0f0f0f0f);
252 return (x
& 0x0000003f);
255 uint32_t floor_log2(uint32_t x
)
264 return (ones32(x
) - 1);
275 /* returns position of first bit that is not 0 from msb,
276 * starting count at lsb */
277 uint32_t wl_min_lzc(uint32_t x
)
300 /* just take the maximum number of bits for interpolation */
301 #define INTERP_BITS (REAL_BITS-TABLE_BITS)
303 static const real_t pow2_tab
[] = {
304 REAL_CONST(1.000000000000000), REAL_CONST(1.010889286051701), REAL_CONST(1.021897148654117),
305 REAL_CONST(1.033024879021228), REAL_CONST(1.044273782427414), REAL_CONST(1.055645178360557),
306 REAL_CONST(1.067140400676824), REAL_CONST(1.078760797757120), REAL_CONST(1.090507732665258),
307 REAL_CONST(1.102382583307841), REAL_CONST(1.114386742595892), REAL_CONST(1.126521618608242),
308 REAL_CONST(1.138788634756692), REAL_CONST(1.151189229952983), REAL_CONST(1.163724858777578),
309 REAL_CONST(1.176396991650281), REAL_CONST(1.189207115002721), REAL_CONST(1.202156731452703),
310 REAL_CONST(1.215247359980469), REAL_CONST(1.228480536106870), REAL_CONST(1.241857812073484),
311 REAL_CONST(1.255380757024691), REAL_CONST(1.269050957191733), REAL_CONST(1.282870016078778),
312 REAL_CONST(1.296839554651010), REAL_CONST(1.310961211524764), REAL_CONST(1.325236643159741),
313 REAL_CONST(1.339667524053303), REAL_CONST(1.354255546936893), REAL_CONST(1.369002422974591),
314 REAL_CONST(1.383909881963832), REAL_CONST(1.398979672538311), REAL_CONST(1.414213562373095),
315 REAL_CONST(1.429613338391970), REAL_CONST(1.445180806977047), REAL_CONST(1.460917794180647),
316 REAL_CONST(1.476826145939499), REAL_CONST(1.492907728291265), REAL_CONST(1.509164427593423),
317 REAL_CONST(1.525598150744538), REAL_CONST(1.542210825407941), REAL_CONST(1.559004400237837),
318 REAL_CONST(1.575980845107887), REAL_CONST(1.593142151342267), REAL_CONST(1.610490331949254),
319 REAL_CONST(1.628027421857348), REAL_CONST(1.645755478153965), REAL_CONST(1.663676580326736),
320 REAL_CONST(1.681792830507429), REAL_CONST(1.700106353718524), REAL_CONST(1.718619298122478),
321 REAL_CONST(1.737333835273706), REAL_CONST(1.756252160373300), REAL_CONST(1.775376492526521),
322 REAL_CONST(1.794709075003107), REAL_CONST(1.814252175500399), REAL_CONST(1.834008086409342),
323 REAL_CONST(1.853979125083386), REAL_CONST(1.874167634110300), REAL_CONST(1.894575981586966),
324 REAL_CONST(1.915206561397147), REAL_CONST(1.936061793492294), REAL_CONST(1.957144124175400),
325 REAL_CONST(1.978456026387951), REAL_CONST(2.000000000000000)
328 static const real_t log2_tab
[] = {
329 REAL_CONST(0.000000000000000), REAL_CONST(0.022367813028455), REAL_CONST(0.044394119358453),
330 REAL_CONST(0.066089190457772), REAL_CONST(0.087462841250339), REAL_CONST(0.108524456778169),
331 REAL_CONST(0.129283016944966), REAL_CONST(0.149747119504682), REAL_CONST(0.169925001442312),
332 REAL_CONST(0.189824558880017), REAL_CONST(0.209453365628950), REAL_CONST(0.228818690495881),
333 REAL_CONST(0.247927513443585), REAL_CONST(0.266786540694901), REAL_CONST(0.285402218862248),
334 REAL_CONST(0.303780748177103), REAL_CONST(0.321928094887362), REAL_CONST(0.339850002884625),
335 REAL_CONST(0.357552004618084), REAL_CONST(0.375039431346925), REAL_CONST(0.392317422778760),
336 REAL_CONST(0.409390936137702), REAL_CONST(0.426264754702098), REAL_CONST(0.442943495848728),
337 REAL_CONST(0.459431618637297), REAL_CONST(0.475733430966398), REAL_CONST(0.491853096329675),
338 REAL_CONST(0.507794640198696), REAL_CONST(0.523561956057013), REAL_CONST(0.539158811108031),
339 REAL_CONST(0.554588851677637), REAL_CONST(0.569855608330948), REAL_CONST(0.584962500721156),
340 REAL_CONST(0.599912842187128), REAL_CONST(0.614709844115208), REAL_CONST(0.629356620079610),
341 REAL_CONST(0.643856189774725), REAL_CONST(0.658211482751795), REAL_CONST(0.672425341971496),
342 REAL_CONST(0.686500527183218), REAL_CONST(0.700439718141092), REAL_CONST(0.714245517666123),
343 REAL_CONST(0.727920454563199), REAL_CONST(0.741466986401147), REAL_CONST(0.754887502163469),
344 REAL_CONST(0.768184324776926), REAL_CONST(0.781359713524660), REAL_CONST(0.794415866350106),
345 REAL_CONST(0.807354922057604), REAL_CONST(0.820178962415188), REAL_CONST(0.832890014164742),
346 REAL_CONST(0.845490050944375), REAL_CONST(0.857980995127572), REAL_CONST(0.870364719583405),
347 REAL_CONST(0.882643049361841), REAL_CONST(0.894817763307943), REAL_CONST(0.906890595608519),
348 REAL_CONST(0.918863237274595), REAL_CONST(0.930737337562886), REAL_CONST(0.942514505339240),
349 REAL_CONST(0.954196310386875), REAL_CONST(0.965784284662087), REAL_CONST(0.977279923499917),
350 REAL_CONST(0.988684686772166), REAL_CONST(1.000000000000000)
353 real_t
pow2_fix(real_t val
)
359 int32_t whole
= (val
>> REAL_BITS
);
362 int32_t rest
= val
- (whole
<< REAL_BITS
);
364 /* index into pow2_tab */
365 int32_t index
= rest
>> (REAL_BITS
-TABLE_BITS
);
369 return (1<<REAL_BITS
);
371 /* leave INTERP_BITS bits */
372 index_frac
= rest
>> (REAL_BITS
-TABLE_BITS
-INTERP_BITS
);
373 index_frac
= index_frac
& ((1<<INTERP_BITS
)-1);
379 retval
= REAL_CONST(1) >> -whole
;
382 x1
= pow2_tab
[index
& ((1<<TABLE_BITS
)-1)];
383 x2
= pow2_tab
[(index
& ((1<<TABLE_BITS
)-1)) + 1];
384 errcorr
= ( (index_frac
*(x2
-x1
))) >> INTERP_BITS
;
388 retval
= retval
* (errcorr
+ x1
);
390 retval
= MUL_R(retval
, (errcorr
+ x1
));
396 int32_t pow2_int(real_t val
)
402 int32_t whole
= (val
>> REAL_BITS
);
405 int32_t rest
= val
- (whole
<< REAL_BITS
);
407 /* index into pow2_tab */
408 int32_t index
= rest
>> (REAL_BITS
-TABLE_BITS
);
414 /* leave INTERP_BITS bits */
415 index_frac
= rest
>> (REAL_BITS
-TABLE_BITS
-INTERP_BITS
);
416 index_frac
= index_frac
& ((1<<INTERP_BITS
)-1);
423 x1
= pow2_tab
[index
& ((1<<TABLE_BITS
)-1)];
424 x2
= pow2_tab
[(index
& ((1<<TABLE_BITS
)-1)) + 1];
425 errcorr
= ( (index_frac
*(x2
-x1
))) >> INTERP_BITS
;
427 retval
= MUL_R(retval
, (errcorr
+ x1
));
432 /* ld(x) = ld(x*y/y) = ld(x/y) + ld(y), with y=2^N and [1 <= (x/y) < 2] */
433 int32_t log2_int(uint32_t val
)
436 uint32_t whole
= (val
);
447 exp
= floor_log2(val
);
456 /* index in the log2 table */
457 index
= frac
>> (REAL_BITS
-TABLE_BITS
);
459 /* leftover part for linear interpolation */
460 index_frac
= frac
& ((1<<(REAL_BITS
-TABLE_BITS
))-1);
462 /* leave INTERP_BITS bits */
463 index_frac
= index_frac
>> (REAL_BITS
-TABLE_BITS
-INTERP_BITS
);
465 x1
= log2_tab
[index
& ((1<<TABLE_BITS
)-1)];
466 x2
= log2_tab
[(index
& ((1<<TABLE_BITS
)-1)) + 1];
468 /* linear interpolation */
469 /* retval = exp + ((index_frac)*x2 + (1-index_frac)*x1) */
471 errcorr
= (index_frac
* (x2
-x1
)) >> INTERP_BITS
;
473 return ((exp
+REAL_BITS
) << REAL_BITS
) + errcorr
+ x1
;
476 /* ld(x) = ld(x*y/y) = ld(x/y) + ld(y), with y=2^N and [1 <= (x/y) < 2] */
477 real_t
log2_fix(uint32_t val
)
480 uint32_t whole
= (val
>> REAL_BITS
);
491 exp
= floor_log2(val
);
500 /* index in the log2 table */
501 index
= frac
>> (REAL_BITS
-TABLE_BITS
);
503 /* leftover part for linear interpolation */
504 index_frac
= frac
& ((1<<(REAL_BITS
-TABLE_BITS
))-1);
506 /* leave INTERP_BITS bits */
507 index_frac
= index_frac
>> (REAL_BITS
-TABLE_BITS
-INTERP_BITS
);
509 x1
= log2_tab
[index
& ((1<<TABLE_BITS
)-1)];
510 x2
= log2_tab
[(index
& ((1<<TABLE_BITS
)-1)) + 1];
512 /* linear interpolation */
513 /* retval = exp + ((index_frac)*x2 + (1-index_frac)*x1) */
515 errcorr
= (index_frac
* (x2
-x1
)) >> INTERP_BITS
;
517 return (exp
<< REAL_BITS
) + errcorr
+ x1
;