common.h

mepg 1 layer3软解码源代码,实现了对MP3文件的软件解码

/**********************************************************************
Copyright (c) 1991 MPEG/audio software simulation group, All Rights Reserved
common.h
**********************************************************************/
/**********************************************************************
 * MPEG/audio coding/decoding software, work in progress              *
 *   NOT for public distribution until verified and approved by the   *
 *   MPEG/audio committee.  For further information, please contact   *
 *   Chad Fogg email: <[e-mail]>                               *
 *                                                                    *
 * VERSION 4.1                                                        *
 *   changes made since last update:                                  *
 *   date   programmers         comment                               *
 * 2/25/91  Doulas Wong,        start of version 1.0 records          *
 *          Davis Pan                                                 *
 * 5/10/91  W. Joseph Carter    Reorganized & renamed all ".h" files  *
 *                              into "common.h" and "encoder.h".      *
 *                              Ported to Macintosh and Unix.         *
 *                              Added additional type definitions for *
 *                              AIFF, double/SANE and "bitstream.c".  *
 *                              Added function prototypes for more    *
 *                              rigorous type checking.               *
 * 27jun91  dpwe (Aware)        Added "alloc_*" defs & prototypes     *
 *                              Defined new struct 'frame_params'.    *
 *                              Changed info.stereo to info.mode_ext  *
 *                              #define constants for mode types      *
 *                              Prototype arguments if PROTO_ARGS     *
 * 5/28/91  Earle Jennings      added MS_DOS definition               *
 *                              MsDos function prototype declarations *
 * 7/10/91  Earle Jennings      added FLOAT definition as double      *
 *10/ 3/91  Don H. Lee          implemented CRC-16 error protection   *
 * 2/11/92  W. Joseph Carter    Ported new code to Macintosh.  Most   *
 *                              important fixes involved changing     *
 *                              16-bit ints to long or unsigned in    *
 *                              bit alloc routines for quant of 65535 *
 *                              and passing proper function args.     *
 *                              Removed "Other Joint Stereo" option   *
 *                              and made bitrate be total channel     *
 *                              bitrate, irrespective of the mode.    *
 *                              Fixed many small bugs & reorganized.  *
 *                              Modified some function prototypes.    *
 *                              Changed BUFFER_SIZE back to 4096.     *
 * 7/27/92  Michael Li          (re-)Ported to MS-DOS                 *
 * 7/27/92  Masahiro Iwadare    Ported to Convex                      *
 * 8/07/92  [e-mail]                                             *
 * 8/10/92  Amit Gulati         Ported to the AIX Platform (RS6000)   *
 *                              AIFF string constants redefined       *
 * 8/27/93 Seymour Shlien,      Fixes in Unix and MSDOS ports,        *
 *         Daniel Lauzon, and                                         *
 *         Bill Truerniet                                             *
 *--------------------------------------------------------------------*
 * 4/23/92  J. Pineda           Added code for Layer III.             *
 * 11/9/92  Amit Gulati         Added defines for layerIII stereo     *
 *                              modes.                                *
 *  8/24/93 Masahiro Iwadare    Included IS modification in Layer III.*
 *                              Changed for 1 pass decoding.          *
 *  9/07/93 Toshiyuki Ishino    Integrated Layer III with Ver 3.9.    *
 *--------------------------------------------------------------------*
 * 11/20/93 Masahiro Iwadare    Integrated Layer III with Ver 4.0.    *
 *--------------------------------------------------------------------*
 *  7/14/94 Juergen Koller      Fix for HPUX an IRIX in AIFF-Strings  *
 **********************************************************************/

/***********************************************************************
*
*  Global Conditional Compile Switches
*
***********************************************************************/

/* #define      UNIX            /* Unix conditional compile switch */
/* #define      MACINTOSH       /* Macintosh conditional compile switch */
/* #define      MS_DOS          /* IBM PC conditional compile switch */
/* #define      MSC60           /* Compiled for MS_DOS with MSC v6.0 */
/* #define      AIX             /* AIX conditional compile switch    */
/* #define      CONVEX          /* CONVEX conditional compile switch */

#if defined(MSC60) 
#ifndef MS_DOS
#define MS_DOS
#endif
#ifndef PROTO_ARGS
#define PROTO_ARGS
#endif
#endif

#ifdef  UNIX
#define         TABLES_PATH     "tables"  /* to find data files */
/* name of environment variable holding path of table files */
#define         MPEGTABENV      "MPEGTABLES"
#define         PATH_SEPARATOR  "/"        /* how to build paths */
#endif  /* UNIX */

#ifdef  MACINTOSH
/* #define      TABLES_PATH ":tables:"  /* where to find data files */
#endif  /* MACINTOSH */

/* 
 * Don't define FAR to far unless you're willing to clean up the 
 * prototypes
 */
#define FAR /*far*/

#ifdef __STDC__
#ifndef PROTO_ARGS
#define PROTO_ARGS
#endif
#endif

#ifdef CONVEX
#define SEEK_SET        0
#define SEEK_CUR        1
#define SEEK_END        2
#endif

/* MS_DOS and VMS do not define TABLES_PATH, so OpenTableFile will default
   to finding the data files in the default directory */

/***********************************************************************
*
*  Global Include Files
*
***********************************************************************/

#include        <stdio.h>
#include        <string.h>
#include        <math.h>

#ifdef  UNIX
#include        <unistd.h>
#endif  /* UNIX */

#ifdef  MACINTOSH
#include        <stdlib.h>
#include        <console.h>
#endif  /* MACINTOSH */

#ifdef  MS_DOS
#include        <stdlib.h>
#ifdef MSC60
#include        <memory.h>
#else
#include        <alloc.h>
#include        <mem.h>
#endif  /* MSC60 */
#endif  /* MS_DOS */

/***********************************************************************
*
*  Global Definitions
*
***********************************************************************/

/* General Definitions */

#ifdef  MS_DOS
#define         FLOAT                   double
#else
#define         FLOAT                   float
#endif

#define         FALSE                   0
#define         TRUE                    1
#define         NULL_CHAR               '\0'

#define         MAX_U_32_NUM            0xFFFFFFFF
#define         PI                      3.14159265358979
#define         PI4                     PI/4
#define         PI64                    PI/64
#define         LN_TO_LOG10             0.2302585093

#define         VOL_REF_NUM             0
#define         MPEG_AUDIO_ID           1
#define         MAC_WINDOW_SIZE         24

#define         MONO                    1
#define         STEREO                  2
#define         BITS_IN_A_BYTE          8
#define         WORD                    16
#define         MAX_NAME_SIZE           81
#define         SBLIMIT                 32
#define         SSLIMIT                 18
#define         FFT_SIZE                1024
#define         HAN_SIZE                512
#define         SCALE_BLOCK             12
#define         SCALE_RANGE             64
#define         SCALE                   32768
#define         CRC16_POLYNOMIAL        0x8005

/* MPEG Header Definitions - Mode Values */

#define         MPG_MD_STEREO           0
#define         MPG_MD_JOINT_STEREO     1
#define         MPG_MD_DUAL_CHANNEL     2
#define         MPG_MD_MONO             3

/* Mode Extention */

#define         MPG_MD_LR_LR             0
#define         MPG_MD_LR_I              1
#define         MPG_MD_MS_LR             2
#define         MPG_MD_MS_I              3

/* AIFF Definitions */

/* 
 * Note:  The value of a multi-character constant
 *        is implementation-defined.
 */
#if !defined(MS_DOS) && !defined(AIX) && !defined(__hpux) && !defined(sgi) && !defined(linux)
#define         IFF_LONG
#define         IFF_ID_FORM             'FORM'
#define         IFF_ID_AIFF             'AIFF'
#define         IFF_ID_COMM             'COMM'
#define         IFF_ID_SSND             'SSND'
#define         IFF_ID_MPEG             'MPEG'
#else
#define         IFF_ID_FORM             "FORM"
#define         IFF_ID_AIFF             "AIFF"
#define         IFF_ID_COMM             "COMM"
#define         IFF_ID_SSND             "SSND"
#define         IFF_ID_MPEG             "MPEG"
#endif

/* "bit_stream.h" Definitions */

#define         MINIMUM         4    /* Minimum size of the buffer in bytes */
#define         MAX_LENGTH      32   /* Maximum length of word written or
                                        read from bit stream */
#define         READ_MODE       0
#define         WRITE_MODE      1
#define         ALIGNING        8
#define         BINARY          0
#define         ASCII           1
#define         BS_FORMAT       ASCII /* BINARY or ASCII = 2x bytes */
#define         BUFFER_SIZE     4096

#define         MIN(A, B)       ((A) < (B) ? (A) : (B))
#define         MAX(A, B)       ((A) > (B) ? (A) : (B))

/***********************************************************************
*
*  Global Type Definitions
*
***********************************************************************/

/* Structure for Reading Layer II Allocation Tables from File */

typedef struct {
    unsigned int    steps;
    unsigned int    bits;
    unsigned int    group;
    unsigned int    quant;
} sb_alloc, *alloc_ptr;

typedef sb_alloc        al_table[SBLIMIT][16];

/* Header Information Structure */

typedef struct {
    int version;
    int lay;
    int error_protection;
    int bitrate_index;
    int sampling_frequency;
    int padding;
    int extension;
    int mode;