ref: c0ae72652fc9619e8b1e8f365ab977614179779a
dir: /libfaad/common.c/
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003 M. Bakker, Ahead Software 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.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through [email protected].
**
** $Id: common.c,v 1.12 2003/11/12 20:47:57 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(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(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(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(uint8_t sr_index, uint8_t object_type, 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(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;
}
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 random_int(void)
{
static const uint32_t rnd_seed = 16428320;
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 );
}
#define LOG2 0.30102999566398
int32_t int_log2(int32_t val)
{
return (int32_t)ceil(log(val)/log(2));
}