guicast/bccapture.C

   1 #include "bccapture.h"
   2 #include "bcresources.h"
   3 #include "bcwindowbase.h"
   4 #include "colormodels.h"
   5 #include "language.h"
   6 #include "vframe.h"
   7 #include <stdlib.h>
   8 #include <stdio.h>
   9 #include <X11/Xutil.h>
  10
  11
  12
  13
  14
  15 // Byte orders:
  16 // 24 bpp packed:         bgr
  17 // 24 bpp unpacked:       0bgr
  18
  19
  20 BC_Capture::BC_Capture(int w, int h, char *display_path)
  21 {
  22         this->w = w;
  23         this->h = h;
  24
  25         data = 0;
  26         use_shm = 1;
  27         init_window(display_path);
  28         allocate_data();
  29 }
  30
  31
  32 BC_Capture::~BC_Capture()
  33 {
  34         delete_data();
  35         XCloseDisplay(display);
  36 }
  37
  38 int BC_Capture::init_window(char *display_path)
  39 {
  40         int bits_per_pixel;
  41         if(display_path && display_path[0] == 0) display_path = NULL;
  42         if((display = XOpenDisplay(display_path)) == NULL)
  43         {
  44                 printf(_("cannot connect to X server.\n"));
  45                 if(getenv("DISPLAY") == NULL)
  46                 printf(_("'DISPLAY' environment variable not set.\n"));
  47                 exit(-1);
  48                 return 1;
  49         }
  50
  51         screen = DefaultScreen(display);
  52         rootwin = RootWindow(display, screen);
  53         vis = DefaultVisual(display, screen);
  54         default_depth = DefaultDepth(display, screen);
  55         client_byte_order = (*(u_int32_t*)"a   ") & 0x00000001;
  56         server_byte_order = (XImageByteOrder(display) == MSBFirst) ? 0 : 1;
  57         char *data = 0;
  58         XImage *ximage;
  59         ximage = XCreateImage(display,
  60                                         vis,
  61                                         default_depth,
  62                                         ZPixmap,
  63                                         0,
  64                                         data,
  65                                         16,
  66                                         16,
  67                                         8,
  68                                         0);
  69         bits_per_pixel = ximage->bits_per_pixel;
  70         XDestroyImage(ximage);
  71         bitmap_color_model = BC_WindowBase::evaluate_color_model(client_byte_order, server_byte_order, bits_per_pixel);
  72
  73 // test shared memory
  74 // This doesn't ensure the X Server is on the local host
  75     if(use_shm && !XShmQueryExtension(display))
  76     {
  77         use_shm = 0;
  78     }
  79         return 0;
  80 }
  81
  82
  83 int BC_Capture::allocate_data()
  84 {
  85 // try shared memory
  86         if(!display) return 1;
  87     if(use_shm)
  88         {
  89             ximage = XShmCreateImage(display, vis, default_depth, ZPixmap, (char*)NULL, &shm_info, w, h);
  90
  91                 shm_info.shmid = shmget(IPC_PRIVATE, h * ximage->bytes_per_line, IPC_CREAT | 0777);
  92                 if(shm_info.shmid < 0) perror("BC_Capture::allocate_data shmget");
  93                 data = (unsigned char *)shmat(shm_info.shmid, NULL, 0);
  94                 shmctl(shm_info.shmid, IPC_RMID, 0);
  95                 ximage->data = shm_info.shmaddr = (char*)data;  // setting ximage->data stops BadValue
  96                 shm_info.readOnly = 0;
  97
  98 // Crashes here if remote server.
  99                 BC_Resources::error = 0;
 100                 XShmAttach(display, &shm_info);
 101         XSync(display, False);
 102                 if(BC_Resources::error)
 103                 {
 104                         XDestroyImage(ximage);
 105                         shmdt(shm_info.shmaddr);
 106                         use_shm = 0;
 107                 }
 108         }
 109
 110         if(!use_shm)
 111         {
 112 // need to use bytes_per_line for some X servers
 113                 data = 0;
 114                 ximage = XCreateImage(display, vis, default_depth, ZPixmap, 0, (char*)data, w, h, 8, 0);
 115                 data = (unsigned char*)malloc(h * ximage->bytes_per_line);
 116                 XDestroyImage(ximage);
 117
 118                 ximage = XCreateImage(display, vis, default_depth, ZPixmap, 0, (char*)data, w, h, 8, 0);
 119         }
 120
 121         row_data = new unsigned char*[h];
 122         for(int i = 0; i < h; i++)
 123         {
 124                 row_data[i] = &data[i * ximage->bytes_per_line];
 125         }
 126 // This differs from the depth parameter of the top_level.
 127         bits_per_pixel = ximage->bits_per_pixel;
 128         return 0;
 129 }
 130
 131 int BC_Capture::delete_data()
 132 {
 133         if(!display) return 1;
 134         if(data)
 135         {
 136                 if(use_shm)
 137                 {
 138                         XShmDetach(display, &shm_info);
 139                         XDestroyImage(ximage);
 140                         shmdt(shm_info.shmaddr);
 141                 }
 142                 else
 143                 {
 144                         XDestroyImage(ximage);
 145                 }
 146
 147 // data is automatically freed by XDestroyImage
 148                 data = 0;
 149                 delete row_data;
 150         }
 151         return 0;
 152 }
 153
 154
 155 int BC_Capture::get_w() { return w; }
 156 int BC_Capture::get_h() { return h; }
 157
 158 // Capture a frame from the screen
 159 #define CAPTURE_FRAME_HEAD \
 160         for(int i = 0; i < h; i++) \
 161         { \
 162                 unsigned char *input_row = row_data[i]; \
 163                 unsigned char *output_row = (unsigned char*)frame->get_rows()[i]; \
 164                 for(int j = 0; j < w; j++) \
 165                 {
 166
 167 #define CAPTURE_FRAME_TAIL \
 168                 } \
 169         }
 170
 171
 172
 173 int BC_Capture::capture_frame(VFrame *frame, int &x1, int &y1)
 174 {
 175         if(!display) return 1;
 176         if(x1 < 0) x1 = 0;
 177         if(y1 < 0) y1 = 0;
 178         if(x1 > get_top_w() - w) x1 = get_top_w() - w;
 179         if(y1 > get_top_h() - h) y1 = get_top_h() - h;
 180
 181
 182 // Read the raw data
 183         if(use_shm)
 184                 XShmGetImage(display, rootwin, ximage, x1, y1, 0xffffffff);
 185         else
 186                 XGetSubImage(display, rootwin, x1, y1, w, h, 0xffffffff, ZPixmap, ximage, 0, 0);
 187
 188         cmodel_transfer(frame->get_rows(),
 189                 row_data,
 190                 frame->get_y(),
 191                 frame->get_u(),
 192                 frame->get_v(),
 193                 0,
 194                 0,
 195                 0,
 196                 0,
 197                 0,
 198                 w,
 199                 h,
 200                 0,
 201                 0,
 202                 frame->get_w(),
 203                 frame->get_h(),
 204                 bitmap_color_model,
 205                 frame->get_color_model(),
 206                 0,
 207                 frame->get_w(),
 208                 w);
 209
 210         return 0;
 211 }
 212
 213 int BC_Capture::get_top_w()
 214 {
 215         Screen *screen_ptr = XDefaultScreenOfDisplay(display);
 216         return WidthOfScreen(screen_ptr);
 217 }
 218
 219 int BC_Capture::get_top_h()
 220 {
 221         Screen *screen_ptr = XDefaultScreenOfDisplay(display);
 222         return HeightOfScreen(screen_ptr);
 223 }
 224 /*
 225 //      Local Variables:
 226 //      mode: C++
 227 //      c-file-style: "linux"
 228 //      End:
 229 */