bmp.1.rar_In the Know_linux BMP

/* showbmp.c */ #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <string.h> #include <linux/fb.h> #include <sys/mman.h> #include <sys/ioctl.h> #include <arpa/inet.h> //14byte typedef struct { char cfType[2]; /* 文件类型, 必须为 "BM" (0x4D42)*/ char cfSize[4]; /* 文件的大小(字节) */ char cfReserved[4]; /* 保留, 必须为 0 */ char cfoffBits[4]; /* 位图阵列相对于文件头的偏移量(字节)*/ }__attribute__((packed)) BITMAPFILEHEADER; /* 文件头结构 */ //40byte typedef struct { char ciSize[4]; /* size of BITMAPINFOHEADER */ char ciWidth[4]; /* 位图宽度(像素) */ char ciHeight[4]; /* 位图高度(像素) */ char ciPlanes[2]; /* 目标设备的位平面数, 必须置为1 */ char ciBitCount[2]; /* 每个像素的位数, 1,4,8或24 */ char ciCompress[4]; /* 位图阵列的压缩方法,0=不压缩 */ char ciSizeImage[4]; /* 图像大小(字节) */ char ciXPelsPerMeter[4];/* 目标设备水平每米像素个数 */ char ciYPelsPerMeter[4];/* 目标设备垂直每米像素个数 */ char ciClrUsed[4]; /* 位图实际使用的颜色表的颜色数 */ char ciClrImportant[4]; /* 重要颜色索引的个数 */ }__attribute__((packed)) BITMAPINFOHEADER; /* 位图信息头结构 */ typedef struct { unsigned short blue:5; unsigned short green:5; unsigned short red:5; unsigned short rev:1; }__attribute__((packed)) PIXEL; BITMAPFILEHEADER FileHead; BITMAPINFOHEADER InfoHead; char *fbp = 0; int xres = 0; int yres = 0; int bits_per_pixel = 0; int show_bmp ( char *bmpfile ); long chartolong ( char * string, int length ); /****************************************************************************** * ******************************************************************************/ int main ( int argc, char *argv[] ) { int fbfd = 0; struct fb_var_screeninfo vinfo; struct fb_fix_screeninfo finfo; long int screensize = 0; // Open the file for reading and writing fbfd = open("/dev/fb0", O_RDWR); if (!fbfd) { printf("Error cannot open framebuffer device.\n"); exit(1); } // Get fixed screen information if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) { printf("Error reading fixed information.\n"); exit(2); } // Get variable screen information if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) { printf("Error reading variable information.\n"); exit(3); } printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel ); xres = vinfo.xres; yres = vinfo.yres; bits_per_pixel = vinfo.bits_per_pixel; // Figure out the size of the screen in bytes screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8; // Map the device to memory fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0); if ((int)fbp == -1) { printf("Error failed to map framebuffer device to memory.\n"); exit(4); } printf("sizeof header=%d\n", sizeof(BITMAPFILEHEADER)); printf("into show_bmp fun\n"); show_bmp( argv[1] ); munmap(fbp, screensize); close(fbfd); return 0; } /****************************************************************************** * ******************************************************************************/ int show_bmp( char *bmpfile ) { FILE *fp; int rc; int ciBitCount, ciWidth, ciHeight; int line_x, line_y; long int location = 0, BytesPerLine = 0; char tmp[1024*10]; /* 打开位图文件 */ fp = fopen( bmpfile, "rb" ); if (fp == NULL) { return( -1 ); } /* 读取位图文件头 */ rc = fread( &FileHead, sizeof(BITMAPFILEHEADER),1, fp ); if ( rc != 1) { printf("read header error!\n"); fclose( fp ); return( -2 ); } /* 判断位图的类型 */ if (memcmp(FileHead.cfType, "BM", 2) != 0) { printf("it's not a BMP file\n"); fclose( fp ); return( -3 ); } /* 读取位图信息头 */ rc = fread( (char *)&InfoHead, sizeof(BITMAPINFOHEADER),1, fp ); if ( rc != 1) { printf("read infoheader error!\n"); fclose( fp ); return( -4 ); } ciWidth = (int) chartolong( InfoHead.ciWidth, 4 ); ciHeight = (int) chartolong( InfoHead.ciHeight, 4 ); ciBitCount = (int) chartolong( InfoHead.ciBitCount, 4 ); fseek(fp, (int)chartolong(FileHead.cfoffBits, 4), SEEK_SET); BytesPerLine = (ciWidth * ciBitCount + 31) / 32 * 4; printf("width=%d, height=%d, bitCount=%d, offset=%d\n", ciWidth, ciHeight, ciBitCount, (int)chartolong(FileHead.cfoffBits, 4)); line_x = line_y = 0; while(!feof(fp)) { PIXEL pix; unsigned short int tmp; rc = fread( (char *)&pix, 1, sizeof(unsigned short int), fp ); if (rc != sizeof(unsigned short int) ) { break; } location = line_x * bits_per_pixel / 8 + (ciHeight - line_y - 1) * xres * bits_per_pixel / 8; tmp=pix.red<<11 | pix.green<<6 | pix.blue; *((unsigned short int*)(fbp + location)) = tmp; line_x++; if (line_x == ciWidth ) { line_x = 0; line_y++; if(line_y==ciHeight-1) { break; } } } fclose( fp ); return( 0 ); } /****************************************************************************** * ******************************************************************************/ long chartolong( char * string, int length ) { long number; if (length <= 4) { memset( &number, 0x00, sizeof(long) ); memcpy( &number, string, length ); } return( number ); }