commondecls.h

JPEG压缩和解压程序和一些相关的说明文档 内容比较全

#include <stdio.h>
#include <stddef.h>
#include  <stdlib.h>
#define SIZEOF(object)  ((size_t) sizeof(object))
typedef unsigned char JSAMPLE;
typedef JSAMPLE  *JSAMPROW;  /* ptr to one image row of pixel samples. */
typedef JSAMPROW *JSAMPARRAY;   /* ptr to some rows (a 2-D sample array) */
typedef long INT32;
/* Datatype used for image dimensions.  The JPEG standard only supports

 * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore

 * "unsigned int" is sufficient on all machines.  However, if you need to

 * handle larger images and you don't mind deviating from the spec, you

 * can change this datatype.

 */
typedef unsigned int JDIMENSION; /*usigned int is 32 bits*/
typedef unsigned char UINT8;

/* UINT16 must hold at least the values 0..65535. */

typedef unsigned short UINT16;
typedef unsigned char U_CHAR;
#define UCH(x)	((int) (x))



#define JFREAD(file,buf,sizeofbuf)  \
  ((size_t) fread((void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
#define JFWRITE(file,buf,sizeofbuf)  \
  ((size_t) fwrite((const void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))

#define	ReadOK(file,buffer,len)	(JFREAD(file,buffer,len) == ((size_t) (len)))
#define WriteOK(file,buffer,len) (JFWRITE(file,buffer,len)==((size_t) (len)))

#define LOCAL(type) static type


/* Private version of data source object */

typedef struct _bmp_source_struct * bmp_source_ptr;

typedef struct _bmp_destination_struct * bmp_destination_ptr;
typedef struct _bmp_source_struct {
  
  FILE *inputfile;              /*source file pointer*/
  JSAMPROW buffer;              /*input buffer pointer*/
  JSAMPROW rgb_buffer;              /*rgb sequence data buffer pointer*/
  INT32 *rgb_gray_tab;
  JSAMPARRAY colormap;		/* BMP colormap (converted to my format) */
  UINT8 colormap_used;          /*the tag of the colormap,in the real_color image,the colormap isn't used*/
  JDIMENSION image_width;
  JDIMENSION image_height;      /* BMP image height*/
  void (* adjust_pixel_rows)(bmp_source_ptr sinfo); 
  
  JDIMENSION row_width;		/* Physical width of scanlines in file */

  int bits_per_pixel;		/* remembers 8- or 24-bit format */
  UINT16 X_density ;             /* 100 cm per meter */
  UINT16 Y_density ;
  UINT8  density_unit ;  	/* dots/cm */
  
} bmp_source_struct;

typedef struct _bmp_destination_struct {
  
  FILE *outputfile;                /*destination file pointer*/
  JSAMPROW buffer;              /*buffer pointer*/
  JDIMENSION image_width;
  JDIMENSION image_height;      /* BMP image height*/
 
  JDIMENSION row_width;		/* Physical width of scanlines in file */
    
} bmp_destination_struct;