git.sesse.net Git - vlc/blob - plugins/gnome/vout_gnome.c

   1 /*****************************************************************************
   2  * vout_gnome.c: Gnome video output display method
   3  *****************************************************************************
   4  * Copyright (C) 1998, 1999, 2000 VideoLAN
   5  *
   6  * Authors:
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24  * Preamble
  25  *****************************************************************************/
  26 #include "defs.h"
  27
  28 #include <errno.h>                                                 /* ENOMEM */
  29 #include <stdlib.h>                                                /* free() */
  30 #include <string.h>                                            /* strerror() */
  31
  32 #ifdef SYS_BSD
  33 #include <sys/types.h>                                     /* typedef ushort */
  34 #endif
  35
  36 #include <sys/shm.h>                                   /* shmget(), shmctl() */
  37 #include <X11/Xlib.h>
  38 #include <X11/Xutil.h>
  39 #include <X11/extensions/XShm.h>
  40
  41 #include "config.h"
  42 #include "common.h"
  43 #include "threads.h"
  44 #include "mtime.h"
  45 #include "plugins.h"
  46
  47 #include "video.h"
  48 #include "video_output.h"
  49
  50 #include "intf_msg.h"
  51
  52 /*****************************************************************************
  53  * vout_sys_t: video output X11 method descriptor
  54  *****************************************************************************
  55  * This structure is part of the video output thread descriptor.
  56  * It describes the X11 specific properties of an output thread. X11 video
  57  * output is performed through regular resizable windows. Windows can be
  58  * dynamically resized to adapt to the size of the streams.
  59  *****************************************************************************/
  60 typedef struct vout_sys_s
  61 {
  62     /* User settings */
  63     boolean_t           b_shm;               /* shared memory extension flag */
  64
  65     /* Internal settings and properties */
  66     Display *           p_display;                        /* display pointer */
  67     Visual *            p_visual;                          /* visual pointer */
  68     int                 i_screen;                           /* screen number */
  69     Window              root_window;                          /* root window */
  70     Window              window;                   /* window instance handler */
  71     GC                  gc;              /* graphic context instance handler */
  72     Colormap            colormap;               /* colormap used (8bpp only) */
  73
  74     /* Display buffers and shared memory information */
  75     XImage *            p_ximage[2];                       /* XImage pointer */
  76     XShmSegmentInfo     shm_info[2];       /* shared memory zone information */
  77 } vout_sys_t;
  78
  79 /*****************************************************************************
  80  * Local prototypes
  81  *****************************************************************************/
  82 static int  X11OpenDisplay      ( vout_thread_t *p_vout, char *psz_display, Window root_window, void *p_data );
  83 static void X11CloseDisplay     ( vout_thread_t *p_vout );
  84 static int  X11CreateWindow     ( vout_thread_t *p_vout );
  85 static void X11DestroyWindow    ( vout_thread_t *p_vout );
  86 static int  X11CreateImage      ( vout_thread_t *p_vout, XImage **pp_ximage );
  87 static void X11DestroyImage     ( XImage *p_ximage );
  88 static int  X11CreateShmImage   ( vout_thread_t *p_vout, XImage **pp_ximage,
  89                                   XShmSegmentInfo *p_shm_info );
  90 static void X11DestroyShmImage  ( vout_thread_t *p_vout, XImage *p_ximage,
  91                                   XShmSegmentInfo *p_shm_info );
  92
  93 /*****************************************************************************
  94  * vout_SysCreate: allocate X11 video thread output method
  95  *****************************************************************************
  96  * This function allocate and initialize a X11 vout method. It uses some of the
  97  * vout properties to choose the window size, and change them according to the
  98  * actual properties of the display.
  99  *****************************************************************************/
 100 int vout_SysCreate( vout_thread_t *p_vout, char *psz_display,
 101                     int i_root_window, void *p_data )
 102 {
 103     /* Allocate structure */
 104     p_vout->p_sys = malloc( sizeof( vout_sys_t ) );
 105     if( p_vout->p_sys == NULL )
 106     {
 107         intf_ErrMsg("error: %s\n", strerror(ENOMEM) );
 108         return( 1 );
 109     }
 110
 111     /* Open and initialize device. This function issues its own error messages.
 112      * Since XLib is usually not thread-safe, we can't use the same display
 113      * pointer than the interface or another thread. However, the root window
 114      * id is still valid. */
 115     if( X11OpenDisplay( p_vout, psz_display, i_root_window, p_data ) )
 116     {
 117         intf_ErrMsg("error: can't initialize X11 display\n" );
 118         free( p_vout->p_sys );
 119         return( 1 );
 120     }
 121
 122     return( 0 );
 123 }
 124
 125 /*****************************************************************************
 126  * vout_SysInit: initialize X11 video thread output method
 127  *****************************************************************************
 128  * This function create the XImages needed by the output thread. It is called
 129  * at the beginning of the thread, but also each time the window is resized.
 130  *****************************************************************************/
 131 int vout_SysInit( vout_thread_t *p_vout )
 132 {
 133     int i_err;
 134
 135     /* Create XImages using XShm extension - on failure, fall back to regular
 136      * way (and destroy the first image if it was created successfully) */
 137     if( p_vout->p_sys->b_shm )
 138     {
 139         /* Create first image */
 140         i_err = X11CreateShmImage( p_vout, &p_vout->p_sys->p_ximage[0],
 141                                    &p_vout->p_sys->shm_info[0] );
 142         if( !i_err )                         /* first image has been created */
 143         {
 144             /* Create second image */
 145             if( X11CreateShmImage( p_vout, &p_vout->p_sys->p_ximage[1],
 146                                    &p_vout->p_sys->shm_info[1] ) )
 147             {                             /* error creating the second image */
 148                 X11DestroyShmImage( p_vout, p_vout->p_sys->p_ximage[0],
 149                                     &p_vout->p_sys->shm_info[0] );
 150                 i_err = 1;
 151             }
 152         }
 153         if( i_err )                                      /* an error occured */
 154         {
 155             intf_Msg("XShm video extension deactivated\n" );
 156             p_vout->p_sys->b_shm = 0;
 157         }
 158     }
 159
 160     /* Create XImages without XShm extension */
 161     if( !p_vout->p_sys->b_shm )
 162     {
 163         if( X11CreateImage( p_vout, &p_vout->p_sys->p_ximage[0] ) )
 164         {
 165             intf_ErrMsg("error: can't create images\n");
 166             p_vout->p_sys->p_ximage[0] = NULL;
 167             p_vout->p_sys->p_ximage[1] = NULL;
 168             return( 1 );
 169         }
 170         if( X11CreateImage( p_vout, &p_vout->p_sys->p_ximage[1] ) )
 171         {
 172             intf_ErrMsg("error: can't create images\n");
 173             X11DestroyImage( p_vout->p_sys->p_ximage[0] );
 174             p_vout->p_sys->p_ximage[0] = NULL;
 175             p_vout->p_sys->p_ximage[1] = NULL;
 176             return( 1 );
 177         }
 178     }
 179
 180     /* Set bytes per line and initialize buffers */
 181     p_vout->i_bytes_per_line = p_vout->p_sys->p_ximage[0]->bytes_per_line;
 182     vout_SetBuffers( p_vout, p_vout->p_sys->p_ximage[ 0 ]->data,
 183                      p_vout->p_sys->p_ximage[ 1 ]->data );
 184     return( 0 );
 185 }
 186
 187 /*****************************************************************************
 188  * vout_SysEnd: terminate X11 video thread output method
 189  *****************************************************************************
 190  * Destroy the X11 XImages created by vout_SysInit. It is called at the end of
 191  * the thread, but also each time the window is resized.
 192  *****************************************************************************/
 193 void vout_SysEnd( vout_thread_t *p_vout )
 194 {
 195     if( p_vout->p_sys->b_shm )                             /* Shm XImages... */
 196     {
 197         X11DestroyShmImage( p_vout, p_vout->p_sys->p_ximage[0],
 198                             &p_vout->p_sys->shm_info[0] );
 199         X11DestroyShmImage( p_vout, p_vout->p_sys->p_ximage[1],
 200                             &p_vout->p_sys->shm_info[1] );
 201     }
 202     else                                          /* ...or regular XImages */
 203     {
 204         X11DestroyImage( p_vout->p_sys->p_ximage[0] );
 205         X11DestroyImage( p_vout->p_sys->p_ximage[1] );
 206     }
 207 }
 208
 209 /*****************************************************************************
 210  * vout_SysDestroy: destroy X11 video thread output method
 211  *****************************************************************************
 212  * Terminate an output method created by vout_CreateOutputMethod
 213  *****************************************************************************/
 214 void vout_SysDestroy( vout_thread_t *p_vout )
 215 {
 216     X11CloseDisplay( p_vout );
 217     free( p_vout->p_sys );
 218 }
 219
 220 /*****************************************************************************
 221  * vout_SysManage: handle X11 events
 222  *****************************************************************************
 223  * This function should be called regularly by video output thread. It manages
 224  * X11 events and allows window resizing. It returns a non null value on
 225  * error.
 226  *****************************************************************************/
 227 int vout_SysManage( vout_thread_t *p_vout )
 228 {
 229     /*
 230      * Color/Grayscale or gamma change: in 8bpp, just change the colormap
 231      */
 232     if( (p_vout->i_changes & VOUT_GRAYSCALE_CHANGE) && (p_vout->i_screen_depth == 8) )
 233     {
 234         /* FIXME: clear flags ?? */
 235     }
 236
 237     /*
 238      * Size change
 239      */
 240     if( p_vout->i_changes & VOUT_SIZE_CHANGE )
 241     {
 242         intf_DbgMsg("resizing window\n");
 243         p_vout->i_changes &= ~VOUT_SIZE_CHANGE;
 244
 245         /* Resize window */
 246         XResizeWindow( p_vout->p_sys->p_display, p_vout->p_sys->window,
 247                        p_vout->i_width, p_vout->i_height );
 248
 249         /* Destroy XImages to change their size */
 250         vout_SysEnd( p_vout );
 251
 252         /* Recreate XImages. If SysInit failed, the thread can't go on. */
 253         if( vout_SysInit( p_vout ) )
 254         {
 255             intf_ErrMsg("error: can't resize display\n");
 256             return( 1 );
 257         }
 258
 259         /* Tell the video output thread that it will need to rebuild YUV
 260          * tables. This is needed since convertion buffer size may have changed */
 261         p_vout->i_changes |= VOUT_YUV_CHANGE;
 262         intf_Msg("Video display resized (%dx%d)\n", p_vout->i_width, p_vout->i_height);
 263     }
 264
 265     return 0;
 266 }
 267
 268 /*****************************************************************************
 269  * vout_SysDisplay: displays previously rendered output
 270  *****************************************************************************
 271  * This function send the currently rendered image to X11 server, wait until
 272  * it is displayed and switch the two rendering buffer, preparing next frame.
 273  *****************************************************************************/
 274 void vout_SysDisplay( vout_thread_t *p_vout )
 275 {
 276     if( p_vout->p_sys->b_shm)                                /* XShm is used */
 277     {
 278         /* Display rendered image using shared memory extension */
 279         XShmPutImage(p_vout->p_sys->p_display, p_vout->p_sys->window, p_vout->p_sys->gc,
 280                      p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ],
 281                      0, 0, 0, 0,
 282                      p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->width,
 283                      p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->height, True);
 284
 285         /* Send the order to the X server */
 286         XFlush(p_vout->p_sys->p_display);
 287     }
 288     else                                /* regular X11 capabilities are used */
 289     {
 290         XPutImage(p_vout->p_sys->p_display, p_vout->p_sys->window, p_vout->p_sys->gc,
 291                   p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ],
 292                   0, 0, 0, 0,
 293                   p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->width,
 294                   p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->height);
 295
 296         /* Send the order to the X server */
 297         XFlush(p_vout->p_sys->p_display);
 298     }
 299 }
 300
 301 /*****************************************************************************
 302  * vout_SetPalette: sets an 8 bpp palette
 303  *****************************************************************************
 304  * This function sets the palette given as an argument. It does not return
 305  * anything, but could later send information on which colors it was unable
 306  * to set.
 307  *****************************************************************************/
 308 void vout_SetPalette( p_vout_thread_t p_vout,
 309                       u16 *red, u16 *green, u16 *blue, u16 *transp )
 310 {
 311     int i;
 312     XColor color[255];
 313
 314     intf_DbgMsg( "Palette change called\n" );
 315
 316     /* allocate palette */
 317     for( i = 0; i < 255; i++ )
 318     {
 319         /* kludge: colors are indexed reversely because color 255 seems
 320          * to be reserved for black even if we try to set it to white */
 321         color[i].pixel = 255-i;
 322         color[i].pad = 0;
 323         color[i].flags = DoRed|DoGreen|DoBlue;
 324         color[i].red = red[255-i];
 325         color[i].blue = blue[255-i];
 326         color[i].green = green[255-i];
 327     }
 328
 329     XStoreColors( p_vout->p_sys->p_display, p_vout->p_sys->colormap, color, 256 );
 330 }
 331
 332 /* following functions are local */
 333
 334 /*****************************************************************************
 335  * X11OpenDisplay: open and initialize X11 device
 336  *****************************************************************************
 337  * Create a window according to video output given size, and set other
 338  * properties according to the display properties.
 339  *****************************************************************************/
 340 static int X11OpenDisplay( vout_thread_t *p_vout, char *psz_display, Window root_window, void *p_data )
 341 {
 342     XPixmapFormatValues *       p_xpixmap_format;          /* pixmap formats */
 343     XVisualInfo *               p_xvisual;           /* visuals informations */
 344     XVisualInfo                 xvisual_template;         /* visual template */
 345     int                         i_count;                       /* array size */
 346
 347     /* Open display */
 348     p_vout->p_sys->p_display = XOpenDisplay( psz_display );
 349     if( p_vout->p_sys->p_display == NULL )
 350     {
 351         intf_ErrMsg("error: can't open display %s\n", psz_display );
 352         return( 1 );
 353     }
 354
 355     /* Initialize structure */
 356     p_vout->p_sys->root_window  = root_window;
 357     p_vout->p_sys->b_shm        = (XShmQueryExtension(p_vout->p_sys->p_display) == True);
 358     p_vout->p_sys->i_screen     = DefaultScreen( p_vout->p_sys->p_display );
 359     if( !p_vout->p_sys->b_shm )
 360     {
 361         intf_Msg("XShm video extension is not available\n");
 362     }
 363
 364     /* Get screen depth */
 365     p_vout->i_screen_depth = XDefaultDepth( p_vout->p_sys->p_display, p_vout->p_sys->i_screen );
 366     switch( p_vout->i_screen_depth )
 367     {
 368     case 8:
 369         /*
 370          * Screen depth is 8bpp. Use PseudoColor visual with private colormap.
 371          */
 372         xvisual_template.screen =   p_vout->p_sys->i_screen;
 373         xvisual_template.class =    DirectColor;
 374         p_xvisual = XGetVisualInfo( p_vout->p_sys->p_display, VisualScreenMask | VisualClassMask,
 375                                     &xvisual_template, &i_count );
 376         if( p_xvisual == NULL )
 377         {
 378             intf_ErrMsg("error: no PseudoColor visual available\n");
 379             XCloseDisplay( p_vout->p_sys->p_display );
 380             return( 1 );
 381         }
 382         p_vout->i_bytes_per_pixel = 1;
 383
 384         /* put the colormap in place */
 385         p_vout->p_sys->colormap = *(Colormap *)p_data;
 386         break;
 387     case 15:
 388     case 16:
 389     case 24:
 390     default:
 391         /*
 392          * Screen depth is higher than 8bpp. TrueColor visual is used.
 393          */
 394         xvisual_template.screen =   p_vout->p_sys->i_screen;
 395         xvisual_template.class =    TrueColor;
 396         p_xvisual = XGetVisualInfo( p_vout->p_sys->p_display, VisualScreenMask | VisualClassMask,
 397                                     &xvisual_template, &i_count );
 398         if( p_xvisual == NULL )
 399         {
 400             intf_ErrMsg("error: no TrueColor visual available\n");
 401             XCloseDisplay( p_vout->p_sys->p_display );
 402             return( 1 );
 403         }
 404         p_vout->i_red_mask =        p_xvisual->red_mask;
 405         p_vout->i_green_mask =      p_xvisual->green_mask;
 406         p_vout->i_blue_mask =       p_xvisual->blue_mask;
 407
 408         /* There is no difference yet between 3 and 4 Bpp. The only way to find
 409          * the actual number of bytes per pixel is to list supported pixmap
 410          * formats. */
 411         p_xpixmap_format = XListPixmapFormats( p_vout->p_sys->p_display, &i_count );
 412         p_vout->i_bytes_per_pixel = 0;
 413         for( ; i_count--; p_xpixmap_format++ )
 414         {
 415             if( p_xpixmap_format->bits_per_pixel / 8 > p_vout->i_bytes_per_pixel )
 416             {
 417                 p_vout->i_bytes_per_pixel = p_xpixmap_format->bits_per_pixel / 8;
 418             }
 419         }
 420         break;
 421     }
 422     p_vout->p_sys->p_visual = p_xvisual->visual;
 423     XFree( p_xvisual );
 424
 425     /* Create a window */
 426     if( X11CreateWindow( p_vout ) )
 427     {
 428         intf_ErrMsg("error: can't open a window\n");
 429         XCloseDisplay( p_vout->p_sys->p_display );
 430         return( 1 );
 431     }
 432     return( 0 );
 433 }
 434
 435 /*****************************************************************************
 436  * X11CloseDisplay: close X11 device
 437  *****************************************************************************
 438  * Returns all resources allocated by X11OpenDisplay and restore the original
 439  * state of the display.
 440  *****************************************************************************/
 441 static void X11CloseDisplay( vout_thread_t *p_vout )
 442 {
 443     /* Destroy colormap */
 444     if( p_vout->i_screen_depth == 8 )
 445     {
 446         XFreeColormap( p_vout->p_sys->p_display, p_vout->p_sys->colormap );
 447     }
 448
 449     /* Destroy window */
 450     X11DestroyWindow( p_vout );
 451
 452     /* FIXME: We should close the display here, but X returns an error. */
 453     //XCloseDisplay( p_vout->p_sys->p_display );
 454 }
 455
 456 /*****************************************************************************
 457  * X11CreateWindow: create X11 vout window
 458  *****************************************************************************
 459  * The video output window will be created. Normally, this window is wether
 460  * full screen or part of a parent window. Therefore, it does not need a
 461  * title or other hints. Thery are still supplied in case the window would be
 462  * spawned as a standalone one by the interface.
 463  *****************************************************************************/
 464 static int X11CreateWindow( vout_thread_t *p_vout )
 465 {
 466     XSetWindowAttributes    xwindow_attributes;         /* window attributes */
 467     XGCValues               xgcvalues;      /* graphic context configuration */
 468     XEvent                  xevent;                          /* first events */
 469     boolean_t               b_expose;             /* 'expose' event received */
 470     boolean_t               b_map_notify;     /* 'map_notify' event received */
 471
 472     /* Prepare window attributes */
 473     xwindow_attributes.backing_store = Always;       /* save the hidden part */
 474
 475     /* Create the window and set hints */
 476     p_vout->p_sys->window = XCreateSimpleWindow( p_vout->p_sys->p_display,
 477                                          p_vout->p_sys->root_window,
 478                                          0, 0,
 479                                          p_vout->i_width, p_vout->i_height,
 480                                          0, 0, 0);
 481     XSelectInput( p_vout->p_sys->p_display, p_vout->p_sys->window,
 482                   ExposureMask | StructureNotifyMask );
 483     XChangeWindowAttributes( p_vout->p_sys->p_display, p_vout->p_sys->window,
 484                              CWBackingStore, &xwindow_attributes);
 485
 486     /* Creation of a graphic context that doesn't generate a GraphicsExpose event
 487        when using functions like XCopyArea */
 488     xgcvalues.graphics_exposures = False;
 489     p_vout->p_sys->gc =  XCreateGC( p_vout->p_sys->p_display, p_vout->p_sys->window,
 490                                     GCGraphicsExposures, &xgcvalues);
 491
 492     /* Send orders to server, and wait until window is displayed - two events
 493      * must be received: a MapNotify event, an Expose event allowing drawing in the
 494      * window */
 495     b_expose = 0;
 496     b_map_notify = 0;
 497     XMapWindow( p_vout->p_sys->p_display, p_vout->p_sys->window);
 498     do
 499     {
 500         XNextEvent( p_vout->p_sys->p_display, &xevent);
 501         if( (xevent.type == Expose)
 502             && (xevent.xexpose.window == p_vout->p_sys->window) )
 503         {
 504             b_expose = 1;
 505         }
 506         else if( (xevent.type == MapNotify)
 507                  && (xevent.xmap.window == p_vout->p_sys->window) )
 508         {
 509             b_map_notify = 1;
 510         }
 511     }
 512     while( !( b_expose && b_map_notify ) );
 513     XSelectInput( p_vout->p_sys->p_display, p_vout->p_sys->window, 0 );
 514
 515     /* At this stage, the window is open, displayed, and ready to receive
 516      * data */
 517     return( 0 );
 518 }
 519
 520 /*****************************************************************************
 521  * X11DestroyWindow: destroy X11 window
 522  *****************************************************************************
 523  * Destroy an X11 window created by vout_CreateWindow
 524  *****************************************************************************/
 525 static void X11DestroyWindow( vout_thread_t *p_vout )
 526 {
 527     XUnmapWindow( p_vout->p_sys->p_display, p_vout->p_sys->window );
 528     XFreeGC( p_vout->p_sys->p_display, p_vout->p_sys->gc );
 529     XDestroyWindow( p_vout->p_sys->p_display, p_vout->p_sys->window );
 530 }
 531
 532 /*****************************************************************************
 533  * X11CreateImage: create an XImage
 534  *****************************************************************************
 535  * Create a simple XImage used as a buffer.
 536  *****************************************************************************/
 537 static int X11CreateImage( vout_thread_t *p_vout, XImage **pp_ximage )
 538 {
 539     byte_t *    pb_data;                          /* image data storage zone */
 540     int         i_quantum;                     /* XImage quantum (see below) */
 541
 542     /* Allocate memory for image */
 543     p_vout->i_bytes_per_line = p_vout->i_width * p_vout->i_bytes_per_pixel;
 544     pb_data = (byte_t *) malloc( p_vout->i_bytes_per_line * p_vout->i_height );
 545     if( !pb_data )                                                  /* error */
 546     {
 547         intf_ErrMsg("error: %s\n", strerror(ENOMEM));
 548         return( 1 );
 549     }
 550
 551     /* Optimize the quantum of a scanline regarding its size - the quantum is
 552        a diviser of the number of bits between the start of two scanlines. */
 553     if( !(( p_vout->i_bytes_per_line ) % 32) )
 554     {
 555         i_quantum = 32;
 556     }
 557     else
 558     {
 559         if( !(( p_vout->i_bytes_per_line ) % 16) )
 560         {
 561             i_quantum = 16;
 562         }
 563         else
 564         {
 565             i_quantum = 8;
 566         }
 567     }
 568
 569     /* Create XImage */
 570     *pp_ximage = XCreateImage( p_vout->p_sys->p_display, p_vout->p_sys->p_visual,
 571                                p_vout->i_screen_depth, ZPixmap, 0, pb_data,
 572                                p_vout->i_width, p_vout->i_height, i_quantum, 0);
 573     if(! *pp_ximage )                                               /* error */
 574     {
 575         intf_ErrMsg( "error: XCreateImage() failed\n" );
 576         free( pb_data );
 577         return( 1 );
 578     }
 579
 580     return 0;
 581 }
 582
 583 /*****************************************************************************
 584  * X11CreateShmImage: create an XImage using shared memory extension
 585  *****************************************************************************
 586  * Prepare an XImage for DisplayX11ShmImage function.
 587  * The order of the operations respects the recommandations of the mit-shm
 588  * document by J.Corbet and K.Packard. Most of the parameters were copied from
 589  * there.
 590  *****************************************************************************/
 591 static int X11CreateShmImage( vout_thread_t *p_vout, XImage **pp_ximage,
 592                               XShmSegmentInfo *p_shm_info)
 593 {
 594     /* Create XImage */
 595     *pp_ximage = XShmCreateImage( p_vout->p_sys->p_display, p_vout->p_sys->p_visual,
 596                                   p_vout->i_screen_depth, ZPixmap, 0,
 597                                   p_shm_info, p_vout->i_width, p_vout->i_height );
 598     if(! *pp_ximage )                                               /* error */
 599     {
 600         intf_ErrMsg("error: XShmCreateImage() failed\n");
 601         return( 1 );
 602     }
 603
 604     /* Allocate shared memory segment - 0777 set the access permission
 605      * rights (like umask), they are not yet supported by X servers */
 606     p_shm_info->shmid = shmget( IPC_PRIVATE,
 607                                 (*pp_ximage)->bytes_per_line * (*pp_ximage)->height,
 608                                 IPC_CREAT | 0777);
 609     if( p_shm_info->shmid < 0)                                      /* error */
 610     {
 611         intf_ErrMsg("error: can't allocate shared image data (%s)\n",
 612                     strerror(errno));
 613         XDestroyImage( *pp_ximage );
 614         return( 1 );
 615     }
 616
 617     /* Attach shared memory segment to process (read/write) */
 618     p_shm_info->shmaddr = (*pp_ximage)->data = shmat(p_shm_info->shmid, 0, 0);
 619     if(! p_shm_info->shmaddr )
 620     {                                                               /* error */
 621         intf_ErrMsg("error: can't attach shared memory (%s)\n",
 622                     strerror(errno));
 623         shmctl( p_shm_info->shmid, IPC_RMID, 0 );      /* free shared memory */
 624         XDestroyImage( *pp_ximage );
 625         return( 1 );
 626     }
 627
 628     /* Mark the shm segment to be removed when there will be no more
 629      * attachements, so it is automatic on process exit or after shmdt */
 630     shmctl( p_shm_info->shmid, IPC_RMID, 0 );
 631
 632     /* Attach shared memory segment to X server (read only) */
 633     p_shm_info->readOnly = True;
 634     if( XShmAttach( p_vout->p_sys->p_display, p_shm_info ) == False )    /* error */
 635     {
 636         intf_ErrMsg("error: can't attach shared memory to X11 server\n");
 637         shmdt( p_shm_info->shmaddr );     /* detach shared memory from process
 638                                            * and automatic free                */
 639         XDestroyImage( *pp_ximage );
 640         return( 1 );
 641     }
 642
 643     /* Send image to X server. This instruction is required, since having
 644      * built a Shm XImage and not using it causes an error on XCloseDisplay */
 645     XFlush( p_vout->p_sys->p_display );
 646     return( 0 );
 647 }
 648
 649 /*****************************************************************************
 650  * X11DestroyImage: destroy an XImage
 651  *****************************************************************************
 652  * Destroy XImage AND associated data. If pointer is NULL, the image won't be
 653  * destroyed (see vout_ManageOutputMethod())
 654  *****************************************************************************/
 655 static void X11DestroyImage( XImage *p_ximage )
 656 {
 657     if( p_ximage != NULL )
 658     {
 659         XDestroyImage( p_ximage );                     /* no free() required */
 660     }
 661 }
 662
 663 /*****************************************************************************
 664  * X11DestroyShmImage
 665  *****************************************************************************
 666  * Destroy XImage AND associated data. Detach shared memory segment from
 667  * server and process, then free it. If pointer is NULL, the image won't be
 668  * destroyed (see vout_ManageOutputMethod())
 669  *****************************************************************************/
 670 static void X11DestroyShmImage( vout_thread_t *p_vout, XImage *p_ximage,
 671                                 XShmSegmentInfo *p_shm_info )
 672 {
 673     /* If pointer is NULL, do nothing */
 674     if( p_ximage == NULL )
 675     {
 676         return;
 677     }
 678
 679     XShmDetach( p_vout->p_sys->p_display, p_shm_info );     /* detach from server */
 680     XDestroyImage( p_ximage );
 681     if( shmdt( p_shm_info->shmaddr ) )  /* detach shared memory from process */
 682     {                                   /* also automatic freeing...         */
 683         intf_ErrMsg( "error: can't detach shared memory (%s)\n",
 684                      strerror(errno) );
 685     }
 686 }
 687
 688