linux的bmp代码

//////////////////////////////////////////////////bmp.c///////////////////////////////////////////// //////////////////////////////////

/*

fbv -- simple image viewer for the linuxframebuffer

Copyright (C) 2002 Tomasz Sterna

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "config.h"

#ifdef FBV_SUPPORT_BMP

#include "fbv.h"

#include

#include

#include

#include

#define BMP_TORASTER_OFFSET 10

#define BMP_SIZE_OFFSET 18

#define BMP_BPP_OFFSET 28

#define BMP_RLE_OFFSET 30

#define BMP_COLOR_OFFSET54

#define fill4B(a) ( ( 4 - ( (a) % 4 ) ) & 0x03)

struct color {

unsigned char red;

unsigned char green;

unsigned char blue;

};

intfh_bmp_id(char *name)//读取位图头信息，判断是否为"BM"

intfd;

char id[2];

fd = open(name, O_RDONLY);//打开文件

if (fd == -1) {

return(0);

}

read(fd, id, 2);

close(fd);

if ( id[0]=='B' && id[1]=='M' ) {

return(1);

}

return(0);

}

void fetch_pallete(intfd, struct color pallete[], int count)//获取调色板信息

{

unsigned char buff[4];

int i;

lseek(fd, BMP_COLOR_OFFSET, SEEK_SET);//fd,28,SEEK_SET:参数28为新的读写位置

for (i=0; i

read(fd, buff, 4);//将fd所指向的文件的4个字节传送给缓冲区（指针）buff所指内存中

pallete[i].red = buff[2];

pallete[i].green = buff[1];

pallete[i].blue = buff[0];

}

return;

}

intfh_bmp_load(char *name,unsigned char *buffer, unsigned char **alpha, intx,int y)

{

#if 1

intfd, bpp, raster, i, j, k, skip;

unsigned char buff[4];

unsigned char *wr_buffer = buffer + x*(y-1)*3;

struct color pallete[256];

fd = open(name, O_RDONLY);

if (fd == -1) {

return(FH_ERROR_FILE);

}

if (lseek(fd, BMP_TORASTER_OFFSET, SEEK_SET) == -1) {//从文件10处开始读写return(FH_ERROR_FORMAT);

}

read(fd, buff, 4);

raster = buff[0] + (buff[1]<<8) + (buff[2]<<16) + (buff[3]<<24);//由上面可知：从bfOffBits

//开始四个字节：每一行扫描的字节数？

if (lseek(fd, BMP_BPP_OFFSET, SEEK_SET) == -1) {

return(FH_ERROR_FORMAT);

}

read(fd, buff, 2);

bpp = buff[0] + (buff[1]<<8);//可得biBitCount(从28开始2个字节)

switch (bpp){

case 1: /* monochrome 单色*/

skip = fill4B(x/8+(x%8?1:0));

/*#define fill4B(a) ( ( 4 - ( (a) % 4 ) ) & 0x03)

1.BMP文件记录一行图像是以字节为单位的。因此，就不存在一个字节中的数据位信息表示的点在不同的两行中。也就是说，

设显示模式位16色，在每个字节分配两个点信息时，如果图像的宽度位奇数，那么最后一个像素点的信息将独占一个字节，

这个字节的后4位将没有意义。接下来的一个字节将开始记录下一行的信息。

2.为了显示的方便，除了真彩色外，其他的每中颜色模式的行字节数要用数据“00”补齐为4的整数倍。

如果显示模式为16色，当图像宽为19时，存储时每行则要补充4-(19/2+1)%4=2个字节

（加1是因为里面有一个像素点要独占了一字节）。如果显示模式为256色，当图像宽为19时，每行也要补充4-19%4=1个字节。

*/

lseek(fd, raster, SEEK_SET);

for (i=0; i

for (j=0; j

read(fd, buff, 1);

for (k=0; k<8; k++) {

if (buff[0] & 0x80) {

*wr_buffer++ = 0xff;

*wr_buffer++ = 0xff;

*wr_buffer++ = 0xff;

} else {

*wr_buffer++ = 0x00;

*wr_buffer++ = 0x00;

*wr_buffer++ = 0x00;

}

buff[0] = buff[0]<<1;

}

}

if (x%8) {

read(fd, buff, 1);

for (k=0; k

if (buff[0] & 0x80) {

*wr_buffer++ = 0xff;

*wr_buffer++ = 0xff;

*wr_buffer++ = 0xff;

} else {

*wr_buffer++ = 0x00;

*wr_buffer++ = 0x00;

*wr_buffer++ = 0x00;

}

buff[0] = buff[0]<<1;

}

}

if (skip) {

read(fd, buff, skip);

}

wr_buffer -= x*6; /* backoff 2 lines - x*2 *3 */

}

break;

case 4: /* 4bit palletized */

skip = fill4B(x/2+x%2);//#define fill4B(a) ( ( 4 - ( (a) % 4 ) ) & 0x03) fetch_pallete(fd, pallete, 16);

lseek(fd, raster, SEEK_SET);

for (i=0; i

for (j=0; j

read(fd, buff, 1);

buff[1] = buff[0]>>4;

buff[2] = buff[0] & 0x0f;

*wr_buffer++ = pallete[buff[1]].red;

*wr_buffer++ = pallete[buff[1]].green;

*wr_buffer++ = pallete[buff[1]].blue;

*wr_buffer++ = pallete[buff[2]].red;

*wr_buffer++ = pallete[buff[2]].green;

*wr_buffer++ = pallete[buff[2]].blue;

}

if (x%2) {

read(fd, buff, 1);

buff[1] = buff[0]>>4;

*wr_buffer++ = pallete[buff[1]].red;

*wr_buffer++ = pallete[buff[1]].green;

*wr_buffer++ = pallete[buff[1]].blue;

}

if (skip) {

read(fd, buff, skip);

}

wr_buffer -= x*6; /* backoff 2 lines - x*2 *3 */ }

break;

case 8: /* 8bit palletized */

skip = fill4B(x);

fetch_pallete(fd, pallete, 256);

lseek(fd, raster, SEEK_SET);

for (i=0; i

for (j=0; j

read(fd, buff, 1);

*wr_buffer++ = pallete[buff[0]].red;

*wr_buffer++ = pallete[buff[0]].green;

*wr_buffer++ = pallete[buff[0]].blue;

}

if (skip) {

read(fd, buff, skip);

}

wr_buffer -= x*6; /* backoff 2 lines - x*2 *3 */ }

break;

case 16: /* 16bit RGB */

return(FH_ERROR_FORMAT);

break;

case 24: /* 24bit RGB */

skip = fill4B(x*3);

lseek(fd, raster, SEEK_SET);

for (i=0; i

for (j=0; j

read(fd, buff, 3);

*wr_buffer++ = buff[2];

*wr_buffer++ = buff[1];

*wr_buffer++ = buff[0];

}

if (skip) {

read(fd, buff, skip);

}

wr_buffer -= x*6; /* backoff 2 lines - x*2 *3 */

}

break;

default:

return(FH_ERROR_FORMAT);

}

close(fd);

return(FH_ERROR_OK);

#endif

}

intfh_bmp_getsize(char *name,int *x,int *y)

{

intfd;

unsigned char size[4];

fd = open(name, O_RDONLY);

if (fd == -1) {

return(FH_ERROR_FILE);//宏定义FH_ERROR_FILE 1; 见fbv.h

}

if (lseek(fd, BMP_SIZE_OFFSET, SEEK_SET) == -1) {//BMP_SIZE_OFFSET :28

return(FH_ERROR_FORMAT);//FH_ERROR_FORMAT:2

}

read(fd, size, 4);

*x = size[0] + (size[1]<<8) + (size[2]<<16) + (size[3]<<24);

// *x-=1;

read(fd, size, 4);

*y = size[0] + (size[1]<<8) + (size[2]<<16) + (size[3]<<24);

close(fd);

return(FH_ERROR_OK);

}

#endif

//////////////////////////////////////////////////bmp.c///////////////////////////////////////////// //////////////////////////////////

//////////////////////////////////////////////////main.c///////////////////////////////////////////// //////////////////////////////////

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include "config.h"

#include "fbv.h"

#include

#include

#if 1

#define UI_w 240

#define UI_h 320

/////////

unsigned char *fbdis = 0;

///////////

staticintopt_clear = 1,

opt_alpha = 0,

opt_hide_cursor = 1,

opt_image_info = 1,

opt_stretch = 0,

opt_delay = 0,

opt_enlarge = 0,

opt_ignore_aspect = 0;

intcmp;

voiddisplay_rgb( unsigned char * dis_data,intW,int H)

{

staticintfbfd = 0;

staticintkh=0;

inttfd=0;

structfb_var_screeninfovinfo;

structfb_fix_screeninfofinfo;

int blank=0;

longintscreensize = 0;

unsigned char * buf;

int x = 0, y = 0,z=0;

// Open the file for reading and writing

fbfd = open("/dev/fb0", O_RDWR);//打开显示设备

if (fbfd< 0) {

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)) {//获取屏的显示信息printf("Error reading variable information.\n");

exit(3);

}

printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel );//vinfo.bits_per_pixel:每个像素

//所占比特，也就是biBitCount

// Figure out the size of the screen in bytes:计算出屏幕大小，单位bit screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;

// Map the device to memory：映射设备到内存

/*

void *mmap(void *start, size_t length, intprot, int flags, intfd, off_toffsize);

mmap（）建立内存映射:将某个文件内容映射到内存中，对该内存区域的存取即是对该文件内容的

读写。参数start指向欲对应的内存起始地址，通常设为NULL,代表让系统自动选定地址，对应成功后

该地址会返回。参数length代表将文件中多大的部分对应到内存。参数prot 代表映射区域的保护方式

有下列组合:PROT_EXEC 映射区域可被执行PROT_READ 映射区域可读PROT_WRITE 映射区域可写

PROT_NONE 映射区域不能存取参数flags会影响映射区域的各种特性。其中，MAP_SHARED:对映射区域的写入

数据会复制回文件中，而且允许其他映射该文件的进程共享参数fd为open（）返回的文件描述符，

代表欲映射到内存的文件。参数offset为文件映射的偏移量，通常设置为0，代表从文件最前方开始对应

返回值：成功：返回映射区的内存起始地址，否则返回MAP_FATLED(-1),错误原因在errno中

*/

fbdis = (unsigned char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0);

if ((int)fbdis == -1) {

printf("Error: failed to map framebuffer device to memory.\n");

exit(4);

}

intyy=0;

if(dis_data){

buf=fbdis;//往显示内存写入RBG

for ( y = 0; y < H/2; y++ )

for ( x = 0; x < W/2; x++ ) {

// buf[ y*Lcd_w*2+x*2] =(dis_data[y*W*3+x*3+2]>>3)|((dis_data[y*W*3+x*3+1]<<3)&0xe0);

// buf[ y*Lcd_w*2+x*2+1] = ((dis_data[y*W*3+x*3+1]>>5)&0x07)|(dis_data[y*W*3+x*3]&0xf8);

//dis_data[y*W*3+x*3]=0;

//dis_data[y*W*3+x*3+1]=x;

//dis_data[y*W*3+x*3+2]=0;

buf [ y*UI_w*2+x*2] =(((dis_data[y*W*3+x*3+2]>>3)&0x1f)|((dis_data[y*W*3+x*3+1]<<1)&0xe0));

buf [ y*UI_w*2+x*2+1] = (((dis_data[y*W*3+x*3+1]>>6)&0x07)|((dis_data[y*W*3+x*3]>>2)&0x78));

// buf [ y*UI_w*2+x*2+1] = ((dis_data[y*W*3+x*3]>>1)&0x78);

}

}

munmap(fbdis, screensize);//关闭设备

close(fbfd);

printf("end of display rgb\n");

}

intdisp_image(char *filename)//显示图片

{

int (*load)(char *, unsigned char *, unsigned char **, int, int);//申明加载

staticint k=1;

unsigned char * image = NULL;

unsigned char * alpha = NULL;

intx_size, y_size, screen_width, screen_height;

intx_pan, y_pan, x_offs, y_offs, refresh = 1, c, ret = 1;

int delay = opt_delay, retransform = 1;

inttransform_stretch = opt_stretch, transform_enlarge = opt_enlarge, transform_cal = (opt_stretch == 2),

transform_iaspect = opt_ignore_aspect, transform_rotation = 0;

#ifdef FBV_SUPPORT_GIF

if(fh_gif_id(filename))

if(fh_gif_getsize(filename, &x_size, &y_size) == FH_ERROR_OK)

{

load = fh_gif_load;

goto identified1;

}

#endif

#ifdef FBV_SUPPORT_PNG

if(fh_png_id(filename))

if(fh_png_getsize(filename, &x_size, &y_size) == FH_ERROR_OK)

{

load = fh_png_load;

goto identified1;

}

#endif

#ifdef FBV_SUPPORT_JPEG

if(fh_jpeg_id(filename))

if(fh_jpeg_getsize(filename, &x_size, &y_size) == FH_ERROR_OK)

{

load = fh_jpeg_load;

goto identified1;

}

#endif

#ifdef FBV_SUPPORT_BMP

if(fh_bmp_id(filename))//判断是否为bmp格式，见bmp.c

if(fh_bmp_getsize(filename, &x_size, &y_size) == FH_ERROR_OK)//读取图片信息

{

load = fh_bmp_load;

goto identified1;

}

#endif

printf("%s: Unable to access file or file format unknown.\n", filename);

return(1);

identified1:

if(!(image = (unsigned char*) malloc(x_size * y_size * 3)))

{

fprintf(stderr, "%s: Out of memory.\n", filename);

gotoerror_mem;

}

if(load(filename, image, &alpha, x_size, y_size) != FH_ERROR_OK)

{

fprintf(stderr, "%s: Image data is corrupt?\n", filename);

// gotoerror_mem;

}

if(!opt_alpha)

{

free(alpha);

alpha = NULL;

}

ret=0;

printf("dx=%d,dy=%d\n",x_size,y_size);

display_rgb(image,x_size,y_size);

done:

if(opt_clear)

{

// printf("\033[H\033[J");

fflush(stdout);

}

error_mem:

free(image);

free(alpha);

return(ret);

}

int main()

{

//////////////////////

/////

disp_image("1.bmp");

printf("begin main 00\n");

}

#endif

//////////////////////////////////////////////////main.c///////////////////////////////////////////// //////////////////////////////////

//////////////////////////////////////////////////config.h//////////////////////////////////////////// /////////////////////////////

#define IDSTRING "fbv 1.0b, s-tech"

#define DEFAULT_FRAMEBUFFER "/dev/fb0"

//#define FBV_SUPPORT_JPEG

//#define FBV_SUPPORT_PNG

#define FBV_SUPPORT_BMP

////////////////////////////////////////////////config.h////////////////////////////////////////////// /////////////////////////////

//////////////////////////////////////////////////fbv.h/////////////////////////////////////////////// ////////////////////////////////

/*

fbv -- simple image viewer for the linuxframebuffer

Copyright (C) 2000, 2001, 2003 MateuszGolicz

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#define FH_ERROR_OK 0

#define FH_ERROR_FILE 1 /* read/access error */

#define FH_ERROR_FORMAT 2 /* file format error */

intdis_w,dis_h;

intone_pic;

voidfb_display(unsigned char *rgbbuff, unsigned char * alpha, intx_size, inty_size, intx_pan, inty_pan, intx_offs, inty_offs);

voidgetCurrentRes(int *x, int *y);

intfh_bmp_id(char *name);

intfh_bmp_load(char *name,unsigned char *buffer, unsigned char **alpha, intx,int y);

intfh_bmp_getsize(char *name,int *x,int *y);

intfh_jpeg_id(char *name);

intfh_jpeg_load(char *name,unsigned char *buffer, unsigned char **alpha, intx,int y);

intfh_jpeg_getsize(char *name,int *x,int *y);

intfh_png_id(char *name);

intfh_png_load(char *name,unsigned char *buffer, unsigned char **alpha, intx,int y);

intfh_png_getsize(char *name,int *x,int *y);

intfh_gif_id(char *name);

intfh_gif_load(char *name,unsigned char *buffer, unsigned char **alpha, intx,int y);

intfh_gif_getsize(char *name,int *x,int *y);

struct image

{

int width, height;

unsigned char *rgb;

unsigned char *alpha;

intdo_free;

};

#ifndef min

#define min(a,b) ((a) < (b) ? (a) : (b))

#endif

#ifndef max

#define max(a,b) ((a) > (b) ? (a) : (b))

#endif

unsigned char * simple_resize(unsigned char * orgin,intox,intoy,intdx,intdy);

unsigned char * alpha_resize(unsigned char * alpha,intox,intoy,intdx,intdy);

unsigned char * color_average_resize(unsigned char * orgin,intox,intoy,intdx,intdy);

unsigned char * rotate(unsigned char *i, int ox, intoy, int rot);

unsigned char * alpha_rotate(unsigned char *i, int ox, intoy, int rot);

voidcenter_resize_qcif(char *disy_buf,char *inpic_buf,intin_w,intin_h);

//////////////////////////////////////////////////fbv.h///////////////////////////////////////////////

////////////////////////////////

//////////////////////////////////////////////////makefile/////////////////////////////////////////// ////////////////////////////////////

#

# Makefile

#

includeMake.conf

CC = arm-linux-gcc

CFLAGS = -O2 -Wall -D_GNU_SOURCE -I/usr/local/include/ # -L/usr/local/lib

SOURCES =main.cbmp.c #in_device.c

OBJECTS = ${SOURCES:.c=.o}

OUT = fbs

#LIBS = -lungif -L/usr/X11R6/lib -ljpeg -lpng

all: $(OUT)

@echo Build DONE.

$(OUT): $(OBJECTS)

$(CC) $(LDFLAGS) $(CFLAGS) -o $(OUT) $(OBJECTS) $(LIBS) $ -lpthread

clean:

rm -f $(OBJECTS) *~ $$$$~* *.bak core config.log $(OUT)

distclean: clean

@echo -e "error:\n\t@echo Please run ./configure first..." >Make.conf

rm -f $(OUT) config.h

install: $(OUT)

cp $(OUT) $(DESTDIR)$(bindir)

gzip -9c $(OUT).1 > $(DESTDIR)$(mandir)/man1/$(OUT).1.gz

uninstall: $(DESTDIR)$(bindir)/$(OUT)

rm -f $(DESTDIR)$(bindir)/$(OUT)

rm -f $(DESTDIR)$(mandir)/man1/$(OUT).1.gz

//////////////////////////////////////////////////makefile/////////////////////////////////////////// ////////////////////////////////////