基于FRAMBUFFER 的电子相册

mian.h

*********************************

  1 #ifndef __MAIN_H__

  2 #define __MAIN_H__
  3
  4 #define SCREEN_BPP 32
  5 #define DEBUG 1
  6
  7 typedef unsigned char u8_t;
  8 typedef unsigned short u16_t;
  9 typedef unsigned int u32_t;
 10
 11 typedef struct
 12 {
 13         int w;
 14         int h;
 15         int bpp;
 16         void *fb_mem;
 17 } info_t;
 18
 19 /* ******************** fb.c ******************** */
 20 extern int init_fb(const char *device, info_t *fb);
 21 extern int fb_pixel(const info_t *fb, int x, int y, u32_t color);
 22 extern int disp_basic(const info_t *fb ,const char *filename);
 23 extern int display(const info_t *fb ,int x ,int y ,const info_t *size ,  const char * filename );
 24 /*******************disp_basic.c******************/
 25 u32_t * rgb24to32(const u8_t *buf24, const info_t* jpeg);
 26 u8_t *decode_jpeg (const char *jpegfile, info_t *jpeg);
 27 u8_t * scale24(const u8_t *buf24, const info_t *new, const info_t *jpeg);
 28 u16_t * rgb24to16(const u8_t *buf24, const  info_t *jpeg);
 29
 30
 31
 32
 33
 34 #endif
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main.c 

**************************************      

  1 #include

  2 #include
  3 #include
  4 #include
  5
  6 #include "main.h"
  7
  8 int main(int argc, char *argv[])
  9 {
 10         info_t fb;
 11
 12         if(init_fb(NULL, &fb) < 0){
 13                 fprintf(stderr, "Error for init framebuffer\n");
 14                 exit(1);
 15         }
 16
 17 ///             fb_pixel(&fb, 640, 400, 0xFF0000);
 18 //              disp_basic(&fb , "1024-768-32.jpg");
 19         info_t size ;
 20         size.w = fb.w ;
 21         size.h = fb.h ;
 22         display(&fb,0 , 0 , &size , "test.jpg") ;
 23         return 0;
 24 }
~               
                                                                                                                    

fb.c

********************************************************************          

1 #include

  2 #include
  3 #include
  4 #include
  5
  6 #include
  7 #include
  8 #include
  9 #include
 10 #include
 11
 12 #include "main.h"
 13 int init_fb(const char *device, info_t *fb)
 14 {
 15         int r = 0;              /* Return value */
 16
 17         if(device == NULL)
 18                 device = "/dev/fb0";
 19
 20         int fd = open(device, O_RDWR);
 21         if(fd < 0){
 22                 fprintf(stderr, "Error for open %s : %s\n",
 23                         device, strerror(errno));
 24                 return -1;
 25         }
 26         /* ioctl  */
 27         struct fb_var_screeninfo fb_var;
 28         if(ioctl(fd, FBIOGET_VSCREENINFO, &fb_var) < 0){
 29                 fprintf(stderr,  "Error for ioctl: %s\n",
 30                         strerror(errno));
 31                 r = -1;
 32                 goto ret;
 33         }
 34
 35         fb->w = fb_var.xres;
 36         fb->h = fb_var.yres;
 37         fb->bpp = fb_var.bits_per_pixel;
 38
 39 #if DEBUG
 40         printf("width: %d\thigh: %d\t bpp: %d\n",
 41                fb->w, fb->h, fb->bpp);
 42 #endif
 43         /* mmap */
 44         if((fb->fb_mem = mmap(NULL, fb->w*fb->h*fb->bpp/8,
 45                               PROT_READ|PROT_WRITE,
 46                               MAP_SHARED,
 47                               fd, 0)) == MAP_FAILED){
 48                 fprintf(stderr, "Error for mmap: %s\n",
 49                         strerror(errno));
 50                 r = -1;
 51                 goto ret;
 52         }
 53
 54 ret:
 55
 56         close(fd);
 57         return r;
 58 }
 59
 60
 61 int fb_pixel(const info_t *fb, int x, int y, u32_t color)
 62 {
 63 #if 0
 64         char *p = fb->fb_mem;
 65         p = p + (x + y * fb->w) * fb->bpp/8 ;
 66         switch(fb->bpp){
 67         case 32:
 68                 *(p+3) = color >> 24;
 69         case 24:
 70                 *(p+2) = color >> 16;
 71         case 16:
 72                 *(p+1) = color >> 8;
 73         default:
 74                 *p = color;
 75         }
 76 #endif
 77 #if (SCREEN_BPP == 32)
 78         u32_t *p = fb->fb_mem;
 79         p = p + x + y * fb->w;
 80         *p = color;
 81 #else
 82         u16_t *p = fb->fb_mem;
 83         p = p + x + y * fb->w;
 84         *p = color;
 85
 86 #endif
 87
 88         return 0;

 89 }

 display.c

**********************************************

  1 #include
  2 #include
  3
  4 #include "main.h"
  5

  6

  7 int disp_basic(const info_t *fb , const char  *filename)
  8 {
  9         FILE *fp =  fopen(filename ,"r");
 10         if(fp == NULL)
 11         {
 12
 13
 14         }
 15         u32_t color = 0xFFFFFF;
 16         int i,j ;
 17         for(j = 0 ;j < fb->h ; ++j)
 18                 {
 19                         for(i = 0 ;i < fb->w ;++i )
 20                         {
 21                         fread(&color , 4,1,fp);
 22                         fb_pixel(fb ,i,j,color);
 23                         }
 24                         usleep(1000) ;
 25                 }
 26         fclose(fp );
 27         return 0 ;
 28 }

~

当然还需要用JPEG 解码库，需要下载解码库文件，我用的是别人已经分装好的函数

                                

Makefile

***********************************************88888                            

2 src = $(wildcard *.c)
  3 obj = $(patsubst %.c, %.o, $(src))
  4 target = main
  5 # COMPILER_PREFIX = arm-linux-
  6 CC = $(COMPILER_PREFIX)gcc
  7 CFLAGS = -Wall -g -c -I../jpeg-8c
  8 LDFLAGS = -Wall -g  -L../jpeg-8c/.libs -ljpeg
  9 all: $(target)
 10 $(target): $(obj)
 11         $(CC) -o $@ $^ $(LDFLAGS)
 12 %.o : %.c
 13         $(CC) $(CFLAGS) -o $@ $<
 14 clean:
 15         -rm -f $(obj)
 16         -rm -f $(target)
 17 .PHONY: clean all
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