common.h

Motion JPEG编解码器源代码

/*
 * 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   *
 *   Davis Pan, 508-493-2241, e-mail: [e-mail]          *
 *                                                                    *
 * VERSION 4.0                                                        *
 *   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                                             *
 * 2004/7/29 Steven Schultz     Cleanup and modernize                 *
 **********************************************************************/

#include        <stdio.h>
#include        <string.h>
#include        <math.h>
#include        <unistd.h>
#include        <stdlib.h>
#include "mjpeg_logging.h"

#define         FLOAT                   float
#define         FALSE                   0
#define         TRUE                    1

#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         MPEG_AUDIO_ID           1

#define         MONO                    1
#define         STEREO                  2
#define         BITS_IN_A_BYTE          8
#define         SBLIMIT                 32
#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

/* "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       BINARY /* 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;
    int mode_ext;
    int copyright;
    int original;
    int emphasis;
} layer, *the_layer;

/* Parent Structure Interpreting some Frame Parameters in Header */

typedef struct {
    layer       *header;        /* raw header information */
    int         actual_mode;    /* when writing IS, may forget if 0 chs */
    al_table    *alloc;         /* bit allocation table read in */
    int         tab_num;        /* number of table as loaded */
    int         stereo;         /* 1 for mono, 2 for stereo */
    int         jsbound;        /* first band of joint stereo coding */
    int         sblimit;        /* total number of sub bands */
    int         in_freq;	/* Freq. input in Hz */
    int         down_freq;	/* Freq. to downsample input to for encoding
								   in Hz */
} frame_params;

/* "bit_stream.h" Type Definitions */

typedef struct  bit_stream_struc {
    FILE        *pt;            /* pointer to bit stream device */
    unsigned char *buf;         /* bit stream buffer */
    int         buf_size;       /* size of buffer (in number of bytes) */
    long        totbit;         /* bit counter of bit stream */
    int         buf_byte_idx;   /* pointer to top byte in buffer */
    int         buf_bit_idx;    /* pointer to top bit of top byte in buffer */
    int         mode;           /* bit stream open in read or write mode */
    int         eob;            /* end of buffer index */
    int         eobs;           /* end of bit stream flag */
    char        format;
    
    /* format of file in rd mode (BINARY/ASCII) */
} Bit_stream_struc;

/***********************************************************************
*
*  Global Variable External Declarations
*
***********************************************************************/

extern const char  *mode_names[4];
extern const char  *layer_names[3];
extern double      s_freq[4];
extern int         bitrate[3][15];
extern double multiple[64];
extern int	   verbose;

/***********************************************************************
*
*  Global Function Prototype Declarations
*
***********************************************************************/

/* The following functions are in the file "common.c" */

extern FILE           *OpenTableFile(char*);
extern int            read_bit_alloc(int, al_table*);
extern int            pick_table(frame_params*);
extern int            js_bound(int, int);
extern void           hdr_to_frps(frame_params*);
extern void           WriteHdr(frame_params*, FILE*);
extern void           WriteBitAlloc(unsigned int[2][SBLIMIT], frame_params*,
                        FILE*);
extern void           WriteScale(unsigned int[2][SBLIMIT],
                        unsigned int[2][SBLIMIT], unsigned int[2][3][SBLIMIT],
                        frame_params*, FILE*);
extern void           WriteSamples(int, unsigned int [SBLIMIT],
                        unsigned int[SBLIMIT], frame_params*, FILE*);
extern int            NumericQ(char*);
extern int            BitrateIndex(int, int);
extern int            SmpFrqIndex(long);
extern void           *mem_alloc(unsigned long, const char*);
extern void           mem_free(void**);
extern void           refill_buffer(Bit_stream_struc*);
extern void           empty_buffer(Bit_stream_struc*, int);
extern void           open_bit_stream_w(Bit_stream_struc*, char*, int);
extern void           open_bit_stream_r(Bit_stream_struc*, char*, int);
extern void           close_bit_stream_r(Bit_stream_struc*);
extern void           close_bit_stream_w(Bit_stream_struc*);
extern void           alloc_buffer(Bit_stream_struc*, int);
extern void           desalloc_buffer(Bit_stream_struc*);
extern void           back_track_buffer(Bit_stream_struc*, int);
extern unsigned int   get1bit(Bit_stream_struc*);
extern void           put1bit(Bit_stream_struc*, int);
extern unsigned long  look_ahead(Bit_stream_struc*, int);
extern unsigned long  getbits(Bit_stream_struc*, int);
extern void           putbits(Bit_stream_struc*, unsigned int, int);
extern void           byte_ali_putbits(Bit_stream_struc*, unsigned int, int);
extern unsigned long  byte_ali_getbits(Bit_stream_struc*, int);
extern unsigned long  sstell(Bit_stream_struc*);
extern int            end_bs(Bit_stream_struc*);
extern int            seek_sync(Bit_stream_struc*, long, int);
extern void           I_CRC_calc(frame_params*, unsigned int[2][SBLIMIT],
                        unsigned int*);
extern void           II_CRC_calc(frame_params*, unsigned int[2][SBLIMIT],
                        unsigned int[2][SBLIMIT], unsigned int*);
extern void           update_CRC(unsigned int, unsigned int, unsigned int*);
extern void           read_absthr(FLOAT*, int);