mirror of https://github.com/mpv-player/mpv
166 lines
5.7 KiB
C
166 lines
5.7 KiB
C
/*
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** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
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** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com
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**
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** This program is free software; you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation; either version 2 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program; if not, write to the Free Software
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** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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**
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** Any non-GPL usage of this software or parts of this software is strictly
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** forbidden.
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**
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** Commercial non-GPL licensing of this software is possible.
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** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
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**
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** $Id: common.c,v 1.6 2003/07/29 08:20:12 menno Exp $
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**/
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/* just some common functions that could be used anywhere */
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#include "common.h"
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#include "structs.h"
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#include "syntax.h"
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/* Returns the sample rate index based on the samplerate */
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uint8_t get_sr_index(uint32_t samplerate)
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{
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if (16428320 <= samplerate) return 11;
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if (92017 <= samplerate) return 0;
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if (75132 <= samplerate) return 1;
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if (55426 <= samplerate) return 2;
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if (46009 <= samplerate) return 3;
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if (37566 <= samplerate) return 4;
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if (27713 <= samplerate) return 5;
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if (23004 <= samplerate) return 6;
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if (18783 <= samplerate) return 7;
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if (13856 <= samplerate) return 8;
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if (11502 <= samplerate) return 9;
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if (9391 <= samplerate) return 10;
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return 11;
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}
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/* Returns 0 if an object type is decodable, otherwise returns -1 */
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int8_t can_decode_ot(uint8_t object_type)
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{
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switch (object_type)
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{
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case LC:
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return 0;
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case MAIN:
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#ifdef MAIN_DEC
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return 0;
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#else
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return -1;
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#endif
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case SSR:
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#ifdef SSR_DEC
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return 0;
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#else
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return -1;
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#endif
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case LTP:
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#ifdef LTP_DEC
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return 0;
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#else
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return -1;
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#endif
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/* ER object types */
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#ifdef ERROR_RESILIENCE
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case ER_LC:
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#ifdef DRM
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case DRM_ER_LC:
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#endif
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return 0;
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case ER_LTP:
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#ifdef LTP_DEC
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return 0;
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#else
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return -1;
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#endif
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case LD:
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#ifdef LD_DEC
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return 0;
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#else
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return -1;
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#endif
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#endif
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}
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return -1;
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}
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static const uint8_t Parity [256] = { // parity
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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,
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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,
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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,
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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,
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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,
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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,
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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,
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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
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};
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static uint32_t __r1 = 1;
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static uint32_t __r2 = 1;
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/*
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* This is a simple random number generator with good quality for audio purposes.
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* It consists of two polycounters with opposite rotation direction and different
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* periods. The periods are coprime, so the total period is the product of both.
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*
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* -------------------------------------------------------------------------------------------------
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* +-> |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|
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* | -------------------------------------------------------------------------------------------------
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* | | | | | | |
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* | +--+--+--+-XOR-+--------+
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* | |
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* +--------------------------------------------------------------------------------------+
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*
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* -------------------------------------------------------------------------------------------------
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* |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| <-+
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* ------------------------------------------------------------------------------------------------- |
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* | | | | |
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* +--+----XOR----+--+ |
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* | |
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* +----------------------------------------------------------------------------------------+
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*
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*
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* The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
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* which gives a period of 18.410.713.077.675.721.215. The result is the
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* XORed values of both generators.
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*/
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uint32_t random_int(void)
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{
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static const uint32_t rnd_seed = 16428320;
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uint32_t t1, t2, t3, t4;
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t3 = t1 = __r1; t4 = t2 = __r2; // Parity calculation is done via table lookup, this is also available
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t1 &= 0xF5; t2 >>= 25; // on CPUs without parity, can be implemented in C and avoid unpredictable
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t1 = Parity [t1]; t2 &= 0x63; // jumps and slow rotate through the carry flag operations.
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t1 <<= 31; t2 = Parity [t2];
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return (__r1 = (t3 >> 1) | t1 ) ^ (__r2 = (t4 + t4) | t2 );
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}
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#define LOG2 0.30102999566398
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int32_t int_log2(int32_t val)
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{
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return (int32_t)ceil(log(val)/log(2));
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}
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