www.pudn.com > JpegTest.rar > JTYPES.H

#define BYTE unsigned char 
#define SBYTE signed char 
#define SWORD signed short int 
#define WORD unsigned short int 
#define DWORD unsigned long int 
#define SDWORD signed long int 
 
static struct APP0infotype { 
		WORD marker;// = 0xFFE0 
		WORD length; // = 16 for usual JPEG, no thumbnail 
		BYTE JFIFsignature[5]; // = "JFIF",'\0' 
		BYTE versionhi; // 1 
		BYTE versionlo; // 1 
		BYTE xyunits;   // 0 = no units, normal density 
		WORD xdensity;  // 1 
		WORD ydensity;  // 1 
		BYTE thumbnwidth; // 0 
		BYTE thumbnheight; // 0 
} APP0info={0xFFE0,16,'J','F','I','F',0,1,1,0,1,1,0,0}; 
 
static struct  SOF0infotype { 
		WORD marker; // = 0xFFC0 
		WORD length; // = 17 for a truecolor YCbCr JPG 
		BYTE precision ;// Should be 8: 8 bits/sample 
		WORD height ; 
		WORD width; 
		BYTE nrofcomponents;//Should be 3: We encode a truecolor JPG 
		BYTE IdY;  // = 1 
		BYTE HVY; // sampling factors for Y (bit 0-3 vert., 4-7 hor.) 
		BYTE QTY;  // Quantization Table number for Y = 0 
		BYTE IdCb; // = 2 
		BYTE HVCb; 
		BYTE QTCb; // 1 
		BYTE IdCr; // = 3 
		BYTE HVCr; 
		BYTE QTCr; // Normally equal to QTCb = 1 
} SOF0info = { 0xFFC0,17,8,0,0,3,1,0x11,0,2,0x11,1,3,0x11,1}; 
// Default sampling factors are 1,1 for every image component: No downsampling 
 
static struct DQTinfotype { 
		 WORD marker;  // = 0xFFDB 
		 WORD length;  // = 132 
		 BYTE QTYinfo;// = 0:  bit 0..3: number of QT = 0 (table for Y) 
				  //       bit 4..7: precision of QT, 0 = 8 bit 
		 BYTE Ytable[64]; 
		 BYTE QTCbinfo; // = 1 (quantization table for Cb,Cr} 
		 BYTE Cbtable[64]; 
		   } DQTinfo; 
// Ytable from DQTinfo should be equal to a scaled and zizag reordered version 
// of the table which can be found in "tables.h": std_luminance_qt 
// Cbtable , similar = std_chrominance_qt 
// We'll init them in the program using set_DQTinfo function 
 
static struct DHTinfotype { 
		 WORD marker;  // = 0xFFC4 
		 WORD length;  //0x01A2 
		 BYTE HTYDCinfo; // bit 0..3: number of HT (0..3), for Y =0 
			  //bit 4  :type of HT, 0 = DC table,1 = AC table 
				//bit 5..7: not used, must be 0 
		 BYTE YDC_nrcodes[16]; //at index i = nr of codes with length i 
		 BYTE YDC_values[12]; 
		 BYTE HTYACinfo; // = 0x10 
		 BYTE YAC_nrcodes[16]; 
		 BYTE YAC_values[162];//we'll use the standard Huffman tables 
		 BYTE HTCbDCinfo; // = 1 
		 BYTE CbDC_nrcodes[16]; 
		 BYTE CbDC_values[12]; 
		 BYTE HTCbACinfo; //  = 0x11 
		 BYTE CbAC_nrcodes[16]; 
		 BYTE CbAC_values[162]; 
} DHTinfo; 
 
static struct SOSinfotype { 
		 WORD marker;  // = 0xFFDA 
		 WORD length; // = 12 
		 BYTE nrofcomponents; // Should be 3: truecolor JPG 
		 BYTE IdY; //1 
		 BYTE HTY; //0 // bits 0..3: AC table (0..3) 
				   // bits 4..7: DC table (0..3) 
		 BYTE IdCb; //2 
		 BYTE HTCb; //0x11 
		 BYTE IdCr; //3 
		 BYTE HTCr; //0x11 
		 BYTE Ss,Se,Bf; // not interesting, they should be 0,63,0 
} SOSinfo={0xFFDA,12,3,1,0,2,0x11,3,0x11,0,0x3F,0}; 
 
typedef struct { BYTE B,G,R; } colorRGB; 
typedef struct { BYTE length; 
		 WORD value;} bitstring; 
 
#define  Y(R,G,B) ((BYTE)( (YRtab[(R)]+YGtab[(G)]+YBtab[(B)])>>16 ) - 128) 
#define Cb(R,G,B) ((BYTE)( (CbRtab[(R)]+CbGtab[(G)]+CbBtab[(B)])>>16 ) ) 
#define Cr(R,G,B) ((BYTE)( (CrRtab[(R)]+CrGtab[(G)]+CrBtab[(B)])>>16 ) ) 
 
#define writebyte(b) fputc((b),fp_jpeg_stream) 
#define writeword(w) writebyte((w)/256);writebyte((w)%256);