linux c编程截取屏幕

共有 3 条评论

1. miftoe 于 2011-04-20 20:57:12发表:

   少了linuxc编程我也许能告诉你简单点的，呵呵

2. hml1006 于 2011-04-20 18:43:09发表:

   搞定

3. hml1006 于 2011-04-20 18:42:45发表:

   从网上找的一个[code]/**************************
   filename:getpicture.c
   
   This file comes from the internet.
   How to compile this file ? Like below.
   
   gcc -o output main.c -lX11 -ljpeg
   ***************************/
   
   #include
   #include
   #include
   
   #include
   
   #include
   
   
   
   /***************************************************************
   Write XImage data to a JPEG file
   
   Must include
   Return value:
   0 - failed
   1 - success
   ****************************************************************/
   static char err_str[256];
   
   int JpegWriteFileFromImage(char *filename, XImage* img)
   {
   FILE* fp;
   struct jpeg_compress_struct cinfo;
   struct jpeg_error_mgr jerr;
   
   fp = fopen(filename,"wb");
   if(fp==NULL)
   {
   memset(err_str, 0, sizeof(err_str));
   sprintf(err_str,"cannot write file %s",filename);
   printf("JpegWriteFileFromImage：%s",err_str);
   return 0;
   }
   
   cinfo.err = jpeg_std_error(&jerr);
   jpeg_create_compress(&cinfo);
   
   jpeg_stdio_dest(&cinfo,fp);
   cinfo.image_width = img->width;
   cinfo.image_height = img->height;
   cinfo.input_components = 3;
   cinfo.in_color_space = JCS_RGB;
   
   jpeg_set_defaults(&cinfo);
   jpeg_start_compress(&cinfo,TRUE);
   
   JSAMPROW row_pointer[1];/* pointer to scanline */
   unsigned char* pBuf = (unsigned char*)malloc(3*img->width);
   row_pointer[0] = pBuf;
   
   int i=0;
   while(cinfo.next_scanline < cinfo.image_height)
   {
   int j=0;
   for(i=0;iwidth;i++)
   {
   //memcpy(pBuf+j,img->data+cinfo.next_scanline*img->bytes_per_line+i*4,3);
   *(pBuf+j) = *(img->data+cinfo.next_scanline*img->bytes_per_line+i*4+2);
   *(pBuf+j+1) = *(img->data+cinfo.next_scanline*img->bytes_per_line+i*4+1);
   *(pBuf+j+2) = *(img->data+cinfo.next_scanline*img->bytes_per_line+i*4);
   j+=3;
   }
   jpeg_write_scanlines(&cinfo,row_pointer,1);
   }
   
   free(pBuf);
   jpeg_finish_compress(&cinfo);
   jpeg_destroy_compress(&cinfo);
   
   fclose(fp);
   return 1;
   }
   
   /*****************************************************************
   Capture a local screenshot of the desktop,
   saving to the file specified by filename.
   If type = 0, then write a bitmap file, else
   write a JPEG file.
   
   Return Value:
   0 - fail
   1 - success
   ******************************************************************/
   int CaptureDesktop(char* filename)
   {
   Window desktop;
   Display* dsp;
   XImage* img;
   
   int screen_width;
   int screen_height;
   
   dsp = XOpenDisplay(NULL);/* Connect to a local display */
   if(NULL==dsp)
   {
   //sprintf(err_str,"Error:Cannot connect to local display\n");
   printf("CaptureDesktop","Cannot connect to local display");
   return 0;
   }
   //desktop = RootWindow(dsp,0);/* Refer to the root window */
   if(0==desktop)
   {
   //printf("cannot get root window\n");
   printf("CaptureDesktop","cannot get root window");
   return 0;
   }
   
   /* Retrive the width and the height of the screen */
   screen_width = DisplayWidth(dsp,0);
   screen_height = DisplayHeight(dsp,0);
   
   /* Get the Image of the root window */
   img = XGetImage(dsp,desktop,0,0,screen_width,screen_height,~0,ZPixmap);
   
   
   JpegWriteFileFromImage(filename,img);
   
   XDestroyImage(img);
   XCloseDisplay(dsp);
   return 1;
   }
   
   int main()
   {
   CaptureDesktop("./screenshot.jpeg");
   //CaptureDesktop("./screenshot.jpg",1);
   printf("Done.\n");
   }
   [/code]