jedi-academy/code/mp3code/l3.h
2013-04-23 15:21:39 +10:00

187 lines
4.1 KiB
C

/*____________________________________________________________________________
FreeAmp - The Free MP3 Player
MP3 Decoder originally Copyright (C) 1996-1997 Xing Technology
Corp. http://www.xingtech.com
Portions Copyright (C) 1998-1999 Emusic.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., 675 Mass Ave, Cambridge, MA 02139, USA.
$Id: L3.h,v 1.7 1999/12/10 07:16:42 elrod Exp $
____________________________________________________________________________*/
/**** L3.h ***************************************************
Layer III structures
*** Layer III is 32 bit only ***
*** Layer III code assumes 32 bit int ***
******************************************************************/
#ifndef L3_H
#define L3_H
#include "config.h"
#define GLOBAL_GAIN_SCALE (4*15)
/* #define GLOBAL_GAIN_SCALE 0 */
#ifdef _M_IX86
#define LITTLE_ENDIAN 1
#endif
#ifdef _M_ALPHA
#define LITTLE_ENDIAN 1
#endif
#ifdef sparc
#define LITTLE_ENDIAN 0
#endif
#if defined(__POWERPC__)
#define LITTLE_ENDIAN 0
#elif defined(__INTEL__)
#define LITTLE_ENDIAN 1
#endif
#ifndef LITTLE_ENDIAN
#error Layer III LITTLE_ENDIAN must be defined 0 or 1
#endif
/*-----------------------------------------------------------*/
/*---- huffman lookup tables ---*/
/* endian dependent !!! */
#if LITTLE_ENDIAN
typedef union
{
int ptr;
struct
{
unsigned char signbits;
unsigned char x;
unsigned char y;
unsigned char purgebits; // 0 = esc
}
b;
}
HUFF_ELEMENT;
#else /* big endian machines */
typedef union
{
int ptr; /* int must be 32 bits or more */
struct
{
unsigned char purgebits; // 0 = esc
unsigned char y;
unsigned char x;
unsigned char signbits;
}
b;
}
HUFF_ELEMENT;
#endif
/*--------------------------------------------------------------*/
typedef struct
{
unsigned int bitbuf;
int bits;
unsigned char *bs_ptr;
unsigned char *bs_ptr0;
unsigned char *bs_ptr_end; // optional for overrun test
}
BITDAT;
/*-- side info ---*/
typedef struct
{
int part2_3_length;
int big_values;
int global_gain;
int scalefac_compress;
int window_switching_flag;
int block_type;
int mixed_block_flag;
int table_select[3];
int subblock_gain[3];
int region0_count;
int region1_count;
int preflag;
int scalefac_scale;
int count1table_select;
}
GR;
typedef struct
{
int mode;
int mode_ext;
/*---------------*/
int main_data_begin; /* beginning, not end, my spec wrong */
int private_bits;
/*---------------*/
int scfsi[2]; /* 4 bit flags [ch] */
GR gr[2][2]; /* [gran][ch] */
}
SIDE_INFO;
/*-----------------------------------------------------------*/
/*-- scale factors ---*/
// check dimensions - need 21 long, 3*12 short
// plus extra for implicit sf=0 above highest cb
typedef struct
{
int l[23]; /* [cb] */
int s[3][13]; /* [window][cb] */
}
SCALEFACT;
/*-----------------------------------------------------------*/
typedef struct
{
int cbtype; /* long=0 short=1 */
int cbmax; /* max crit band */
// int lb_type; /* long block type 0 1 3 */
int cbs0; /* short band start index 0 3 12 (12=no shorts */
int ncbl; /* number long cb's 0 8 21 */
int cbmax_s[3]; /* cbmax by individual short blocks */
}
CB_INFO;
/*-----------------------------------------------------------*/
/* scale factor infor for MPEG2 intensity stereo */
typedef struct
{
int nr[3];
int slen[3];
int intensity_scale;
}
IS_SF_INFO;
#ifndef SAMPLE
#include "small_header.h"
#endif
/*-----------------------------------------------------------*/
#endif // #ifndef L3_H