ref: 3ba088193fc0e9b022957fb348cfdfe1d60daab7
dir: aacdec/libfaad/common.c
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** The "appropriate copyright message" mentioned in section 2c of the GPLv2
** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
**
** $Id: common.c,v 1.27 2008/03/23 23:03:28 menno Exp $
**/
/* just some common functions that could be used anywhere */
#include "common.h"
#include "structs.h"
#include "syntax.h"
/* Returns the sample rate index based on the samplerate */
uint8_t get_sr_index(const uint32_t samplerate)
{
if (92017 <= samplerate) return 0;
if (75132 <= samplerate) return 1;
if (55426 <= samplerate) return 2;
if (46009 <= samplerate) return 3;
if (37566 <= samplerate) return 4;
if (27713 <= samplerate) return 5;
if (23004 <= samplerate) return 6;
if (18783 <= samplerate) return 7;
if (13856 <= samplerate) return 8;
if (11502 <= samplerate) return 9;
if (9391 <= samplerate) return 10;
if (16428320 <= samplerate) return 11;
return 11;
}
/* Returns the sample rate based on the sample rate index */
uint32_t get_sample_rate(const uint8_t sr_index)
{
static const uint32_t sample_rates[] =
{
96000, 88200, 64000, 48000, 44100, 32000,
24000, 22050, 16000, 12000, 11025, 8000
};
if (sr_index < 12)
return sample_rates[sr_index];
return 0;
}
uint8_t max_pred_sfb(const uint8_t sr_index)
{
static const uint8_t pred_sfb_max[] =
{
33, 33, 38, 40, 40, 40, 41, 41, 37, 37, 37, 34
};
if (sr_index < 12)
return pred_sfb_max[sr_index];
return 0;
}
uint8_t max_tns_sfb(const uint8_t sr_index, const uint8_t object_type,
const uint8_t is_short)
{
/* entry for each sampling rate
* 1 Main/LC long window
* 2 Main/LC short window
* 3 SSR long window
* 4 SSR short window
*/
static const uint8_t tns_sbf_max[][4] =
{
{31, 9, 28, 7}, /* 96000 */
{31, 9, 28, 7}, /* 88200 */
{34, 10, 27, 7}, /* 64000 */
{40, 14, 26, 6}, /* 48000 */
{42, 14, 26, 6}, /* 44100 */
{51, 14, 26, 6}, /* 32000 */
{46, 14, 29, 7}, /* 24000 */
{46, 14, 29, 7}, /* 22050 */
{42, 14, 23, 8}, /* 16000 */
{42, 14, 23, 8}, /* 12000 */
{42, 14, 23, 8}, /* 11025 */
{39, 14, 19, 7}, /* 8000 */
{39, 14, 19, 7}, /* 7350 */
{0,0,0,0},
{0,0,0,0},
{0,0,0,0}
};
uint8_t i = 0;
if (is_short) i++;
if (object_type == SSR) i += 2;
return tns_sbf_max[sr_index][i];
}
/* Returns 0 if an object type is decodable, otherwise returns -1 */
int8_t can_decode_ot(const uint8_t object_type)
{
switch (object_type)
{
case LC:
return 0;
case MAIN:
#ifdef MAIN_DEC
return 0;
#else
return -1;
#endif
case SSR:
#ifdef SSR_DEC
return 0;
#else
return -1;
#endif
case LTP:
#ifdef LTP_DEC
return 0;
#else
return -1;
#endif
/* ER object types */
#ifdef ERROR_RESILIENCE
case ER_LC:
#ifdef DRM
case DRM_ER_LC:
#endif
return 0;
case ER_LTP:
#ifdef LTP_DEC
return 0;
#else
return -1;
#endif
case LD:
#ifdef LD_DEC
return 0;
#else
return -1;
#endif
#endif
}
return -1;
}
void *faad_malloc(size_t size)
{
#if 0 // defined(_WIN32) && !defined(_WIN32_WCE)
return _aligned_malloc(size, 16);
#else // #ifdef 0
return malloc(size);
#endif // #ifdef 0
}
/* common free function */
void faad_free(void *b)
{
#if 0 // defined(_WIN32) && !defined(_WIN32_WCE)
_aligned_free(b);
#else
free(b);
}
#endif
static const uint8_t Parity [256] = { // parity
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,
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,
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,
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,
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,
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,
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,
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
};
static uint32_t __r1 = 1;
static uint32_t __r2 = 1;
/*
* This is a simple random number generator with good quality for audio purposes.
* It consists of two polycounters with opposite rotation direction and different
* periods. The periods are coprime, so the total period is the product of both.
*
* -------------------------------------------------------------------------------------------------
* +-> |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|
* | -------------------------------------------------------------------------------------------------
* | | | | | | |
* | +--+--+--+-XOR-+--------+
* | |
* +--------------------------------------------------------------------------------------+
*
* -------------------------------------------------------------------------------------------------
* |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| <-+
* ------------------------------------------------------------------------------------------------- |
* | | | | |
* +--+----XOR----+--+ |
* | |
* +----------------------------------------------------------------------------------------+
*
*
* The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
* which gives a period of 18.410.713.077.675.721.215. The result is the
* XORed values of both generators.
*/
uint32_t ne_rng(uint32_t *__r1, uint32_t *__r2)
{
uint32_t t1, t2, t3, t4;
t3 = t1 = *__r1; t4 = t2 = *__r2; // Parity calculation is done via table lookup, this is also available
t1 &= 0xF5; t2 >>= 25; // on CPUs without parity, can be implemented in C and avoid unpredictable
t1 = Parity [t1]; t2 &= 0x63; // jumps and slow rotate through the carry flag operations.
t1 <<= 31; t2 = Parity [t2];
return (*__r1 = (t3 >> 1) | t1 ) ^ (*__r2 = (t4 + t4) | t2 );
}
static uint32_t ones32(uint32_t x)
{
x -= ((x >> 1) & 0x55555555);
x = (((x >> 2) & 0x33333333) + (x & 0x33333333));
x = (((x >> 4) + x) & 0x0f0f0f0f);
x += (x >> 8);
x += (x >> 16);
return (x & 0x0000003f);
}
static uint32_t floor_log2(uint32_t x)
{
#if 1
x |= (x >> 1);
x |= (x >> 2);
x |= (x >> 4);
x |= (x >> 8);
x |= (x >> 16);
return (ones32(x) - 1);
#else
uint32_t count = 0;
while (x >>= 1)
count++;
return count;
#endif
}
/* returns position of first bit that is not 0 from msb,
* starting count at lsb */
uint32_t wl_min_lzc(uint32_t x)
{
#if 1
x |= (x >> 1);
x |= (x >> 2);
x |= (x >> 4);
x |= (x >> 8);
x |= (x >> 16);
return (ones32(x));
#else
uint32_t count = 0;
while (x >>= 1)
count++;
return (count + 1);
#endif
}
#ifdef FIXED_POINT
#define TABLE_BITS 6
/* just take the maximum number of bits for interpolation */
#define INTERP_BITS (REAL_BITS-TABLE_BITS)
static const real_t pow2_tab[] = {
REAL_CONST(1.000000000000000), REAL_CONST(1.010889286051701), REAL_CONST(1.021897148654117),
REAL_CONST(1.033024879021228), REAL_CONST(1.044273782427414), REAL_CONST(1.055645178360557),
REAL_CONST(1.067140400676824), REAL_CONST(1.078760797757120), REAL_CONST(1.090507732665258),
REAL_CONST(1.102382583307841), REAL_CONST(1.114386742595892), REAL_CONST(1.126521618608242),
REAL_CONST(1.138788634756692), REAL_CONST(1.151189229952983), REAL_CONST(1.163724858777578),
REAL_CONST(1.176396991650281), REAL_CONST(1.189207115002721), REAL_CONST(1.202156731452703),
REAL_CONST(1.215247359980469), REAL_CONST(1.228480536106870), REAL_CONST(1.241857812073484),
REAL_CONST(1.255380757024691), REAL_CONST(1.269050957191733), REAL_CONST(1.282870016078778),
REAL_CONST(1.296839554651010), REAL_CONST(1.310961211524764), REAL_CONST(1.325236643159741),
REAL_CONST(1.339667524053303), REAL_CONST(1.354255546936893), REAL_CONST(1.369002422974591),
REAL_CONST(1.383909881963832), REAL_CONST(1.398979672538311), REAL_CONST(1.414213562373095),
REAL_CONST(1.429613338391970), REAL_CONST(1.445180806977047), REAL_CONST(1.460917794180647),
REAL_CONST(1.476826145939499), REAL_CONST(1.492907728291265), REAL_CONST(1.509164427593423),
REAL_CONST(1.525598150744538), REAL_CONST(1.542210825407941), REAL_CONST(1.559004400237837),
REAL_CONST(1.575980845107887), REAL_CONST(1.593142151342267), REAL_CONST(1.610490331949254),
REAL_CONST(1.628027421857348), REAL_CONST(1.645755478153965), REAL_CONST(1.663676580326736),
REAL_CONST(1.681792830507429), REAL_CONST(1.700106353718524), REAL_CONST(1.718619298122478),
REAL_CONST(1.737333835273706), REAL_CONST(1.756252160373300), REAL_CONST(1.775376492526521),
REAL_CONST(1.794709075003107), REAL_CONST(1.814252175500399), REAL_CONST(1.834008086409342),
REAL_CONST(1.853979125083386), REAL_CONST(1.874167634110300), REAL_CONST(1.894575981586966),
REAL_CONST(1.915206561397147), REAL_CONST(1.936061793492294), REAL_CONST(1.957144124175400),
REAL_CONST(1.978456026387951), REAL_CONST(2.000000000000000)
};
static const real_t log2_tab[] = {
REAL_CONST(0.000000000000000), REAL_CONST(0.022367813028455), REAL_CONST(0.044394119358453),
REAL_CONST(0.066089190457772), REAL_CONST(0.087462841250339), REAL_CONST(0.108524456778169),
REAL_CONST(0.129283016944966), REAL_CONST(0.149747119504682), REAL_CONST(0.169925001442312),
REAL_CONST(0.189824558880017), REAL_CONST(0.209453365628950), REAL_CONST(0.228818690495881),
REAL_CONST(0.247927513443585), REAL_CONST(0.266786540694901), REAL_CONST(0.285402218862248),
REAL_CONST(0.303780748177103), REAL_CONST(0.321928094887362), REAL_CONST(0.339850002884625),
REAL_CONST(0.357552004618084), REAL_CONST(0.375039431346925), REAL_CONST(0.392317422778760),
REAL_CONST(0.409390936137702), REAL_CONST(0.426264754702098), REAL_CONST(0.442943495848728),
REAL_CONST(0.459431618637297), REAL_CONST(0.475733430966398), REAL_CONST(0.491853096329675),
REAL_CONST(0.507794640198696), REAL_CONST(0.523561956057013), REAL_CONST(0.539158811108031),
REAL_CONST(0.554588851677637), REAL_CONST(0.569855608330948), REAL_CONST(0.584962500721156),
REAL_CONST(0.599912842187128), REAL_CONST(0.614709844115208), REAL_CONST(0.629356620079610),
REAL_CONST(0.643856189774725), REAL_CONST(0.658211482751795), REAL_CONST(0.672425341971496),
REAL_CONST(0.686500527183218), REAL_CONST(0.700439718141092), REAL_CONST(0.714245517666123),
REAL_CONST(0.727920454563199), REAL_CONST(0.741466986401147), REAL_CONST(0.754887502163469),
REAL_CONST(0.768184324776926), REAL_CONST(0.781359713524660), REAL_CONST(0.794415866350106),
REAL_CONST(0.807354922057604), REAL_CONST(0.820178962415188), REAL_CONST(0.832890014164742),
REAL_CONST(0.845490050944375), REAL_CONST(0.857980995127572), REAL_CONST(0.870364719583405),
REAL_CONST(0.882643049361841), REAL_CONST(0.894817763307943), REAL_CONST(0.906890595608519),
REAL_CONST(0.918863237274595), REAL_CONST(0.930737337562886), REAL_CONST(0.942514505339240),
REAL_CONST(0.954196310386875), REAL_CONST(0.965784284662087), REAL_CONST(0.977279923499917),
REAL_CONST(0.988684686772166), REAL_CONST(1.000000000000000)
};
real_t pow2_fix(real_t val)
{
uint32_t x1, x2;
uint32_t errcorr;
uint32_t index_frac;
real_t retval;
int32_t whole = (val >> REAL_BITS);
/* rest = [0..1] */
int32_t rest = val - (whole << REAL_BITS);
/* index into pow2_tab */
int32_t index = rest >> (REAL_BITS-TABLE_BITS);
if (val == 0)
return (1<<REAL_BITS);
/* leave INTERP_BITS bits */
index_frac = rest >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
index_frac = index_frac & ((1<<INTERP_BITS)-1);
if (whole > 0)
{
retval = 1 << whole;
} else {
retval = REAL_CONST(1) >> -whole;
}
x1 = pow2_tab[index & ((1<<TABLE_BITS)-1)];
x2 = pow2_tab[(index & ((1<<TABLE_BITS)-1)) + 1];
errcorr = ( (index_frac*(x2-x1))) >> INTERP_BITS;
if (whole > 0)
{
retval = retval * (errcorr + x1);
} else {
retval = MUL_R(retval, (errcorr + x1));
}
return retval;
}
int32_t pow2_int(real_t val)
{
uint32_t x1, x2;
uint32_t errcorr;
uint32_t index_frac;
real_t retval;
int32_t whole = (val >> REAL_BITS);
/* rest = [0..1] */
int32_t rest = val - (whole << REAL_BITS);
/* index into pow2_tab */
int32_t index = rest >> (REAL_BITS-TABLE_BITS);
if (val == 0)
return 1;
/* leave INTERP_BITS bits */
index_frac = rest >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
index_frac = index_frac & ((1<<INTERP_BITS)-1);
if (whole > 0)
retval = 1 << whole;
else
retval = 0;
x1 = pow2_tab[index & ((1<<TABLE_BITS)-1)];
x2 = pow2_tab[(index & ((1<<TABLE_BITS)-1)) + 1];
errcorr = ( (index_frac*(x2-x1))) >> INTERP_BITS;
retval = MUL_R(retval, (errcorr + x1));
return retval;
}
/* ld(x) = ld(x*y/y) = ld(x/y) + ld(y), with y=2^N and [1 <= (x/y) < 2] */
int32_t log2_int(uint32_t val)
{
uint32_t frac;
uint32_t whole = (val);
int32_t exp = 0;
uint32_t index;
uint32_t index_frac;
uint32_t x1, x2;
uint32_t errcorr;
/* error */
if (val == 0)
return -10000;
exp = floor_log2(val);
exp -= REAL_BITS;
/* frac = [1..2] */
if (exp >= 0)
frac = val >> exp;
else
frac = val << -exp;
/* index in the log2 table */
index = frac >> (REAL_BITS-TABLE_BITS);
/* leftover part for linear interpolation */
index_frac = frac & ((1<<(REAL_BITS-TABLE_BITS))-1);
/* leave INTERP_BITS bits */
index_frac = index_frac >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
x1 = log2_tab[index & ((1<<TABLE_BITS)-1)];
x2 = log2_tab[(index & ((1<<TABLE_BITS)-1)) + 1];
/* linear interpolation */
/* retval = exp + ((index_frac)*x2 + (1-index_frac)*x1) */
errcorr = (index_frac * (x2-x1)) >> INTERP_BITS;
return ((exp+REAL_BITS) << REAL_BITS) + errcorr + x1;
}
/* ld(x) = ld(x*y/y) = ld(x/y) + ld(y), with y=2^N and [1 <= (x/y) < 2] */
real_t log2_fix(uint32_t val)
{
uint32_t frac;
uint32_t whole = (val >> REAL_BITS);
int8_t exp = 0;
uint32_t index;
uint32_t index_frac;
uint32_t x1, x2;
uint32_t errcorr;
/* error */
if (val == 0)
return -100000;
exp = floor_log2(val);
exp -= REAL_BITS;
/* frac = [1..2] */
if (exp >= 0)
frac = val >> exp;
else
frac = val << -exp;
/* index in the log2 table */
index = frac >> (REAL_BITS-TABLE_BITS);
/* leftover part for linear interpolation */
index_frac = frac & ((1<<(REAL_BITS-TABLE_BITS))-1);
/* leave INTERP_BITS bits */
index_frac = index_frac >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
x1 = log2_tab[index & ((1<<TABLE_BITS)-1)];
x2 = log2_tab[(index & ((1<<TABLE_BITS)-1)) + 1];
/* linear interpolation */
/* retval = exp + ((index_frac)*x2 + (1-index_frac)*x1) */
errcorr = (index_frac * (x2-x1)) >> INTERP_BITS;
return (exp << REAL_BITS) + errcorr + x1;
}
#endif