jpg转bmp的C源代码

#ifndef __JPEGDEC_H__ #define __JPEGDEC_H__ #include <stdio.h> #include <stdlib.h> #include <string.h> #define BYTE unsigned char #define WORD unsigned short int #define DWORD unsigned int #define SDWORD signed int #define SBYTE signed char #define SWORD signed short int int load_JPEG_header(FILE *fp, DWORD *X_image, DWORD *Y_image); void decode_JPEG_image(); int get_JPEG_buffer(WORD X_image,WORD Y_image, BYTE **address_dest_buffer); #endif #include <conio.h> #include <time.h> char *FileName="image.jpg"; extern char error_string[90]; typedef struct s_BM_header { WORD BMP_id ; // 'B''M' DWORD size; // size in bytes of the BMP file DWORD zero_res; // 0 DWORD offbits; // 54 DWORD biSize; // 0x28 DWORD Width; // X DWORD Height; // Y WORD biPlanes; // 1 WORD biBitCount ; // 24 DWORD biCompression; // 0 = BI_RGB DWORD biSizeImage; // 0 DWORD biXPelsPerMeter; // 0xB40 DWORD biYPelsPerMeter; // 0xB40 DWORD biClrUsed; //0 DWORD biClrImportant; //0 } BM_header; typedef struct s_RGB { BYTE B; BYTE G; BYTE R; } RGB; void exitmessage(char *message) { printf("%s\n",message);exit(0); } void write_buf_to_BMP(BYTE *im_buffer, WORD X_bitmap, WORD Y_bitmap, char *BMPname) { SWORD x,y; RGB *pixel; BM_header BH; FILE *fp_bitmap; DWORD im_loc_bytes; BYTE nr_fillingbytes, i; BYTE zero_byte=0; fp_bitmap=fopen(BMPname,"wb"); if (fp_bitmap==NULL) exitmessage("File cannot be created"); if (X_bitmap%4!=0) nr_fillingbytes=4-((X_bitmap*3L)%4); else nr_fillingbytes=0; BH.BMP_id = 'M'*256+'B'; fwrite(&BH.BMP_id,2,1,fp_bitmap); BH.size=54+Y_bitmap*(X_bitmap*3+nr_fillingbytes);fwrite(&BH.size,4,1,fp_bitmap); BH.zero_res = 0; fwrite(&BH.zero_res,4,1,fp_bitmap); BH.offbits = 54; fwrite(&BH.offbits,4,1,fp_bitmap); BH.biSize = 0x28; fwrite(&BH.biSize,4,1,fp_bitmap); BH.Width = X_bitmap; fwrite(&BH.Width,4,1,fp_bitmap); BH.Height = Y_bitmap; fwrite(&BH.Height,4,1,fp_bitmap); BH.biPlanes = 1; fwrite(&BH.biPlanes,2,1,fp_bitmap); BH.biBitCount = 24; fwrite(&BH.biBitCount,2,1,fp_bitmap); BH.biCompression = 0; fwrite(&BH.biCompression,4,1,fp_bitmap); BH.biSizeImage = 0; fwrite(&BH.biSizeImage,4,1,fp_bitmap); BH.biXPelsPerMeter = 0xB40; fwrite(&BH.biXPelsPerMeter,4,1,fp_bitmap); BH.biYPelsPerMeter = 0xB40; fwrite(&BH.biYPelsPerMeter,4,1,fp_bitmap); BH.biClrUsed = 0; fwrite(&BH.biClrUsed,4,1,fp_bitmap); BH.biClrImportant = 0; fwrite(&BH.biClrImportant,4,1,fp_bitmap); printf("Writing bitmap ...\n"); im_loc_bytes=(DWORD)im_buffer+((DWORD)Y_bitmap-1)*X_bitmap*4; for (y=0;y<Y_bitmap;y++) { for (x=0;x<X_bitmap;x++) { pixel=(RGB *)im_loc_bytes; fwrite(pixel, 3, 1, fp_bitmap); im_loc_bytes+=4; } for (i=0;i<nr_fillingbytes;i++) fwrite(&zero_byte,1,1,fp_bitmap); im_loc_bytes-=2L*X_bitmap*4; } printf("Done.\n"); fclose(fp_bitmap); } // Used markers: #define SOI 0xD8 #define EOI 0xD9 #define APP0 0xE0 #define SOF 0xC0 #define DQT 0xDB #define DHT 0xC4 #define SOS 0xDA #define DRI 0xDD #define COM 0xFE char error_string[90]; #define exit_func(err) { strcpy(error_string, err); return 0;} static BYTE *buf; // the buffer we use for storing the entire JPG file static BYTE bp; //current byte static WORD wp; //current word static DWORD byte_pos; // current byte position #define BYTE_p(i) bp=buf[(i)++] #define WORD_p(i) wp=(((WORD)(buf[(i)]))<<8) + buf[(i)+1]; (i)+=2 // WORD X_image_size,Y_image_size; // X,Y sizes of the image static WORD X_round,Y_round; // The dimensions rounded to multiple of Hmax*8 (X_round) // and Ymax*8 (Y_round) static BYTE *im_buffer; // RGBA image buffer static DWORD X_image_bytes; // size in bytes of 1 line of the image = X_round * 4 static DWORD y_inc_value ; // 32*X_round; // used by decode_MCU_1x2,2x1,2x2 BYTE YH,YV,CbH,CbV,CrH,CrV; // sampling factors (horizontal and vertical) for Y,Cb,Cr static WORD Hmax,Vmax; static BYTE zigzag[64]={ 0, 1, 5, 6,14,15,27,28, 2, 4, 7,13,16,26,29,42, 3, 8,12,17,25,30,41,43, 9,11,18,24,31,40,44,53, 10,19,23,32,39,45,52,54, 20,22,33,38,46,51,55,60, 21,34,37,47,50,56,59,61, 35,36,48,49,57,58,62,63 }; typedef struct { BYTE Length[17]; // k =1-16 ; L[k] indicates the number of Huffman codes of length k WORD minor_code[17]; // indicates the value of the smallest Huffman code of length k WORD major_code[17]; // similar, but the highest code BYTE V[65536]; // V[k][j] = Value associated to the j-th Huffman code of length k // High nibble = nr of previous 0 coefficients // Low nibble = size (in bits) of the coefficient which will be taken from the data stream } Huffman_table; static float *QT[4]; // quantization tables, no more than 4 quantization tables (QT[0..3]) static Huffman_table HTDC[4]; //DC huffman tables , no more than 4 (0..3) static Huffman_table HTAC[4]; //AC huffman tables (0..3) static BYTE YQ_nr,CbQ_nr,CrQ_nr; // quantization table number for Y, Cb, Cr static BYTE YDC_nr,CbDC_nr,CrDC_nr; // DC Huffman table number for Y,Cb, Cr static BYTE YAC_nr,CbAC_nr,CrAC_nr; // AC Huffman table number for Y,Cb, Cr static BYTE Restart_markers; // if 1 => Restart markers on , 0 => no restart markers static WORD MCU_restart; //Restart markers appears every MCU_restart MCU blocks typedef void (*decode_MCU_func)(DWORD); static SWORD DCY, DCCb, DCCr; // Coeficientii DC pentru Y,Cb,Cr static SWORD DCT_coeff[64]; // Current DCT_coefficients static BYTE Y[64],Cb[64],Cr[64]; // Y, Cb, Cr of the current 8x8 block for the 1x1 case static BYTE Y_1[64],Y_2[64],Y_3[64],Y_4[64]; static BYTE tab_1[64],tab_2[64],tab_3[64],tab_4[64]; // tabelele de supraesantionare pt cele 4 blocuri static SWORD Cr_tab[256],Cb_tab[256]; // Precalculated Cr, Cb tables static SWORD Cr_Cb_green_tab[65536]; // Initial conditions: // byte_pos = start position in the Huffman coded segment // WORD_get(w1); WORD_get(w2);wordval=w1; static BYTE d_k=0; // Bit displacement in memory, relative to the offset of w1 // it's always <16 static WORD w1,w2; // w1 = First word in memory; w2 = Second word static DWORD wordval ; // the actual used value in Huffman decoding. static DWORD mask[17]; static SWORD neg_pow2[17]={0,-1,-3,-7,-15,-31,-63,-127,-255,-511,-1023,-2047,-4095,-8191,-16383,-32767}; static DWORD start_neg_pow2=(DWORD)neg_pow2; static int shift_temp; #define RIGHT_SHIFT(x,shft) \ ((shift_temp = (x)) < 0 ? \ (shift_temp >> (shft)) | ((~(0L)) << (32-(shft))) : \ (shift_temp >> (shft))) #define DESCALE(x,n) RIGHT_SHIFT((x) + (1L << ((n)-1)), n) #define RANGE_MASK 1023L static BYTE *rlimit_table; void prepare_range_limit_table() /* Allocate and fill in the sample_range_limit table */ { int j; rlimit_table = (BYTE *)malloc(5 * 256L + 128) ; /* First segment of "simple" table: limit[x] = 0 for x < 0 */ memset((void *)rlimit_table,0,256); rlimit_table += 256; /* allow negative subscripts of simple table */ /* Main part of "simple" table: limit[x] = x */ for (j = 0; j < 256; j++) rlimit_table[j] = j; /* End of simple table, rest of first half of post-IDCT table */ for (j = 256; j < 640; j++) rlimit_table[j] = 255; /* Second half of post-IDCT table */ memset((void *)(rlimit_table + 640),0,384); for (j = 0; j < 128 ; j++) rlimit_table[j+1024] = j; } #ifdef _MSC_VER WORD lookKbits(BYTE k) { _asm { mov dl, k mov cl, 16 sub cl, dl mov eax, [wordval] shr eax, cl } } WORD WORD_hi_lo(BYTE byte_high,BYTE byte_low) { _asm { mov ah,byte_high mov al,byte_low } } SWORD get_svalue(BYTE k) // k>0 always // Takes k bits out of the BIT stream (wordval),