h.c

看名字就知道了

      location = (x + xoffset) * 2 +
            (y + yoffset) * vd->finfo.line_length;  
      *((unsigned short int*)(vd->fbp + location )) = *img_ptr++;
    }
  }
}

*/


/*********************************************************************************************************
** Function name: open_framebuffer
** Descriptions: 该函数用于初始化FrameBuffer设备，在该函数中打开FrameBuffer设备，并将设备影射到内存
** Input: *ptr,打开Framebuffer设备路径指针
**        *vd ,参数指针
** Output : 返回非0值表示出错
** Created by:
** Created Date:
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date:
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int open_framebuffer(char *ptr,fb_v41 *vd)
{
  int fbfd,screensize;
     // Open the file for reading and writing
    fbfd = open( ptr, O_RDWR);
    if (fbfd < 0)
    {
    printf("Error: cannot open framebuffer device.%x\n",fbfd);
    return ERR_FRAME_BUFFER;
    }
    printf("The framebuffer device was opened successfully.\n");
  
  vd->fbfd = fbfd; // 保存打开FrameBuffer设备的句柄
 
    // Get fixed screen information 获取FrameBuffer固定不变的信息
    if (ioctl(fbfd, FBIOGET_FSCREENINFO, &vd->finfo))
    {
    printf("Error reading fixed information.\n");
    return ERR_FRAME_BUFFER;
    }

    // Get variable screen information 获取FrameBuffer屏幕可变的信息
    if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vd->vinfo))
    {
    printf("Error reading variable information.\n");
    return ERR_FRAME_BUFFER;
    }

    printf("%dx%d, %dbpp, xoffset=%d ,yoffset=%d \n", vd->vinfo.xres,
       vd->vinfo.yres, vd->vinfo.bits_per_pixel,vd->vinfo.xoffset,vd->vinfo.yoffset );

    // Figure out the size of the screen in bytes
    screensize = vd->vinfo.xres * vd->vinfo.yres * vd->vinfo.bits_per_pixel / 8;

    // Map the device to memory
    vd->fbp = (char *)mmap(0,screensize,PROT_READ|PROT_WRITE,MAP_SHARED,fbfd,0); // 影射Framebuffer设备到内存
    if ((int)vd->fbp == -1)
    {
    printf("Error: failed to map framebuffer device to memory.\n");
    return ERR_FRAME_BUFFER;
    }
    printf("The framebuffer device was mapped to memory successfully.\n");
  return  0;
}

/*********************************************************************************************************
** Function name: open_video
** Descriptions: 通过该函数初始化视频设备
** Input: *fileptr，打开的文件名指针
**     *vd，参数指针
**     dep，像素深度
**     pal，调色板
**     width，宽度
**     height，高度
** Output : 无
** Created by:
** Created Date:
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date:
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int open_video( char *fileptr,fb_v41 *vd ,int dep,int pal,int width,int height)
{
  // 打开视频设备

   if ((vd->fd = open(fileptr, O_RDWR)) < 0)
  {
      perror("v4l_open:");
      return ERR_VIDEO_OPEN;
   }
    printf("=============Open Video Success=======================");
   // 获取设备
   if (ioctl(vd->fd, VIDIOCGCAP, &(vd->capability)) < 0)
   {
      perror("v4l_get_capability:");
      return ERR_VIDEO_GCAP;
   }
  

   printf("=============Get Device Success=======================");
  // 获取图象 
   if (ioctl(vd->fd, VIDIOCGPICT, &(vd->picture)) < 0)
   {
      perror("v4l_get_picture");
      return ERR_VIDEO_GPIC;
   }
      printf("=============Get Picture Success=======================");
   // 设置图象
   vd->picture.palette = pal;  // 调色板
   vd->picture.depth = dep;   // 像素深度
//printf("=====Capture depth:%d,Palette:%d================\n",vpic.depth,vpic.palette);
   vd->mmap.format =pal;
   if (ioctl(vd->fd, VIDIOCSPICT, &(vd->picture)) < 0)
   {
      perror("v4l_set_palette");
      return ERR_VIDEO_SPIC;
   }
   //
   vd->mmap.width = width;   // width;
   vd->mmap.height = height;  // height;
   vd->mmap.format = vd->picture.palette;

   vd->frame_current = 0;
   vd->frame_using[0] = 0;
   vd->frame_using[1] = 0;
  
   // 获取缓冲影射信息
   if (ioctl(vd->fd, VIDIOCGMBUF, &(vd->mbuf)) < 0)
   {
      perror("v4l_get_mbuf");
      return -1;
   }
  
   // 建立设备内存影射
   vd->map = mmap(0, vd->mbuf.size, PROT_READ|PROT_WRITE, MAP_SHARED, vd->fd, 0);
   if ( vd->map < 0)
   {
      perror("v4l_mmap_init:mmap");
      return -1;
   }
       printf("The video device was opened successfully.\n");
  // return get_first_frame(vd);
  return 0;
}

/* int write_jpeg(char *filename,unsigned char *img,int widtd,int height,int quality,int gray)
{
   struct jpeg_compress_struct jcfg;
   struct ipeg_error_mgr jerr;
   FILE *fp;
   unsigned char*line;
   int line_length;
   int i;


   if((fp=fopen(filename,"w"))==NULL) {
      fprintf(stderr,"writg_jpeg:can't open %s:%s\n",filename,strerror(errno));
      return -1;
     }
  
   jcfg.image_width=width;
   jcfg.image_height=height;
   jcfg.input_components=gray ? 1:3; //3 simple per pixel (RGB)
   jcfg.in_color_space=gray ? JCS_GRAYSCALE:JCS_RGB;
   jcfg.err=jpeg_std_error(&jerr);

   jpeg_set_defaults(&jcfg);
   jpeg_set_quality(&jcfg,quality,TRUE);
   jpeg_start_compress(&jcfg,TRUE);

   line_finish_compress(&jcfg);
  for(i=0,line=img;i<height;i++,line+=line_length);
            jpeg_write_scanlines(&jcfg,&line,1);

   jpeg_finish_compress(&jcfg);
   jpeg_destroy_compress(&jcfg);
   fclose(fp);
  
   return 0;
}
*/


/**************************************************************************************************************
**
**
***************************************************************************************************************/
int main( void )
{
  fb_v41 vd;
  int ret,i;
  unsigned short  *imageptr;
  unsigned short  tempbuf[320*240*3];
  ret = open_framebuffer(FB_FILE,&vd);  // 打开FrameBuffer设备
  if( 0!= ret )              // 打开FrameBuffer设备
  {
    goto err;
  } 
  for(i=0;i<320*240*3;i++)
   tempbuf[i] = 0xffff;
  rgb_to_framebuffer(&vd,320,240,0,0,tempbuf); // 填充FrameBuffer颜色至整个屏幕
  

  ret = open_video( V4L_FILE, &vd ,
                    32,             // 像素深度
           VIDEO_PALETTE_RGB565,   // 设置调包板
           320,240 );
  if( 0!= ret )   // 打开视频设备失败
  {
    goto err;
  }
  
 printf(vd.capability.name);printf(", Type:%d\n",vd.capability.type);
    printf("Maxwidth:%d,Maxheight:%d\n",vd.capability.maxwidth ,vd.capability.maxheight);
    printf("Minwidth:%d,Minheight:%d\n",vd.capability.minwidth,vd.capability.minheight);
    printf("Channels:%d,Audios:%d\n",vd.capability.channels,vd.capability.audios);
    printf("------Pic Size:%d-------\n",vd.mbuf.size);
  
  while(1)
  {
    imageptr = (unsigned short *) get_frame_address( &vd ); //
    rgb_to_framebuffer(&vd,vd.mmap.width,vd.mmap.height,
                       0,0,imageptr);   //
    if(get_next_frame( &vd ) !=0 ) 
    { // 获取图像数据出错
     goto err;
    }

  }
 // write_jpeg("1.jpg",img,320,240,50,0);
 //  exit(0);
err:
 if(vd.fbfd)
  close(vd.fbfd);    // 关闭FrameBuffer设备
 
 if(vd.fd)
  close(vd.fd);
 exit(0);
 return 0;
}