git.sesse.net Git - vlc/blob - plugins/x11/vout_x11.c

   1 /*****************************************************************************
   2  * vout_x11.c: X11 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 sextension 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)
 233         && (p_vout->i_screen_depth == 8) )
 234     {
 235         /* FIXME: clear flags ?? */
 236     }
 237
 238     /*
 239      * Size change
 240      */
 241     if( p_vout->i_changes & VOUT_SIZE_CHANGE )
 242     {
 243         intf_DbgMsg("resizing window\n");
 244         p_vout->i_changes &= ~VOUT_SIZE_CHANGE;
 245
 246         /* Resize window */
 247         XResizeWindow( p_vout->p_sys->p_display, p_vout->p_sys->window,
 248                        p_vout->i_width, p_vout->i_height );
 249
 250         /* Destroy XImages to change their size */
 251         vout_SysEnd( p_vout );
 252
 253         /* Recreate XImages. If SysInit failed, the thread can't go on. */
 254         if( vout_SysInit( p_vout ) )
 255         {
 256             intf_ErrMsg("error: can't resize display\n");
 257             return( 1 );
 258         }
 259
 260         /* Tell the video output thread that it will need to rebuild YUV
 261          * tables. This is needed since conversion buffer size may have
 262          * changed */
 263         p_vout->i_changes |= VOUT_YUV_CHANGE;
 264         intf_Msg("Video display resized (%dx%d)\n", p_vout->i_width, p_vout->i_height);
 265     }
 266
 267     return 0;
 268 }
 269
 270 /*****************************************************************************
 271  * vout_SysDisplay: displays previously rendered output
 272  *****************************************************************************
 273  * This function send the currently rendered image to X11 server, wait until
 274  * it is displayed and switch the two rendering buffer, preparing next frame.
 275  *****************************************************************************/
 276 void vout_SysDisplay( vout_thread_t *p_vout )
 277 {
 278     if( p_vout->p_sys->b_shm)                                /* XShm is used */
 279     {
 280         /* Display rendered image using shared memory extension */
 281         XShmPutImage(p_vout->p_sys->p_display, p_vout->p_sys->window, p_vout->p_sys->gc,
 282                      p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ],
 283                      0, 0, 0, 0,
 284                      p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->width,
 285                      p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->height, True);
 286
 287         /* Send the order to the X server */
 288         XFlush(p_vout->p_sys->p_display);
 289     }
 290     else                                /* regular X11 capabilities are used */
 291     {
 292         XPutImage(p_vout->p_sys->p_display, p_vout->p_sys->window, p_vout->p_sys->gc,
 293                   p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ],
 294                   0, 0, 0, 0,
 295                   p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->width,
 296                   p_vout->p_sys->p_ximage[ p_vout->i_buffer_index ]->height);
 297
 298         /* Send the order to the X server */
 299         XFlush(p_vout->p_sys->p_display);
 300     }
 301 }
 302
 303 /*****************************************************************************
 304  * vout_SetPalette: sets an 8 bpp palette
 305  *****************************************************************************
 306  * This function sets the palette given as an argument. It does not return
 307  * anything, but could later send information on which colors it was unable
 308  * to set.
 309  *****************************************************************************/
 310 void vout_SetPalette( p_vout_thread_t p_vout,
 311                       u16 *red, u16 *green, u16 *blue, u16 *transp )
 312 {
 313     int i;
 314     XColor color[255];
 315
 316     intf_DbgMsg( "Palette change called\n" );
 317
 318     /* allocate palette */
 319     for( i = 0; i < 255; i++ )
 320     {
 321         /* kludge: colors are indexed reversely because color 255 seems
 322          * to be reserved for black even if we try to set it to white */
 323         color[i].pixel = 255-i;
 324         color[i].pad = 0;
 325         color[i].flags = DoRed|DoGreen|DoBlue;
 326         color[i].red = red[255-i];
 327         color[i].blue = blue[255-i];
 328         color[i].green = green[255-i];
 329     }
 330
 331     XStoreColors( p_vout->p_sys->p_display, p_vout->p_sys->colormap, color, 256 );
 332 }
 333
 334 /* following functions are local */
 335
 336 /*****************************************************************************
 337  * X11OpenDisplay: open and initialize X11 device
 338  *****************************************************************************
 339  * Create a window according to video output given size, and set other
 340  * properties according to the display properties.
 341  *****************************************************************************/
 342 static int X11OpenDisplay( vout_thread_t *p_vout, char *psz_display, Window root_window, void *p_data )
 343 {
 344     XPixmapFormatValues *       p_xpixmap_format;          /* pixmap formats */
 345     XVisualInfo *               p_xvisual;           /* visuals informations */
 346     XVisualInfo                 xvisual_template;         /* visual template */
 347     int                         i_count;                       /* array size */
 348
 349     /* Open display */
 350     p_vout->p_sys->p_display = XOpenDisplay( psz_display );
 351     if( p_vout->p_sys->p_display == NULL )
 352     {
 353         intf_ErrMsg("error: can't open display %s\n", psz_display );
 354         return( 1 );
 355     }
 356
 357     /* Initialize structure */
 358     p_vout->p_sys->root_window  = root_window;
 359     p_vout->p_sys->b_shm        = (XShmQueryExtension(p_vout->p_sys->p_display) == True);
 360     p_vout->p_sys->i_screen     = DefaultScreen( p_vout->p_sys->p_display );
 361     if( !p_vout->p_sys->b_shm )
 362     {
 363         intf_Msg("XShm video extension is not available\n");
 364     }
 365
 366     /* Get screen depth */
 367     p_vout->i_screen_depth = XDefaultDepth( p_vout->p_sys->p_display, p_vout->p_sys->i_screen );
 368     switch( p_vout->i_screen_depth )
 369     {
 370     case 8:
 371         /*
 372          * Screen depth is 8bpp. Use PseudoColor visual with private colormap.
 373          */
 374         xvisual_template.screen =   p_vout->p_sys->i_screen;
 375         xvisual_template.class =    DirectColor;
 376         p_xvisual = XGetVisualInfo( p_vout->p_sys->p_display, VisualScreenMask | VisualClassMask,
 377                                     &xvisual_template, &i_count );
 378         if( p_xvisual == NULL )
 379         {
 380             intf_ErrMsg("error: no PseudoColor visual available\n");
 381             XCloseDisplay( p_vout->p_sys->p_display );
 382             return( 1 );
 383         }
 384         p_vout->i_bytes_per_pixel = 1;
 385
 386         /* put the colormap in place */
 387         p_vout->p_sys->colormap = *(Colormap *)p_data;
 388         break;
 389     case 15:
 390     case 16:
 391     case 24:
 392     default:
 393         /*
 394          * Screen depth is higher than 8bpp. TrueColor visual is used.
 395          */
 396         xvisual_template.screen =   p_vout->p_sys->i_screen;
 397         xvisual_template.class =    TrueColor;
 398         p_xvisual = XGetVisualInfo( p_vout->p_sys->p_display, VisualScreenMask | VisualClassMask,
 399                                     &xvisual_template, &i_count );
 400         if( p_xvisual == NULL )
 401         {
 402             intf_ErrMsg("error: no TrueColor visual available\n");
 403             XCloseDisplay( p_vout->p_sys->p_display );
 404             return( 1 );
 405         }
 406         p_vout->i_red_mask =        p_xvisual->red_mask;
 407         p_vout->i_green_mask =      p_xvisual->green_mask;
 408         p_vout->i_blue_mask =       p_xvisual->blue_mask;
 409
 410         /* There is no difference yet between 3 and 4 Bpp. The only way to find
 411          * the actual number of bytes per pixel is to list supported pixmap
 412          * formats. */
 413         p_xpixmap_format = XListPixmapFormats( p_vout->p_sys->p_display, &i_count );
 414
 415         /* FIXME: under XFree4.0, we can get some strange values. Check this */
 416         p_vout->i_bytes_per_pixel = 0;
 417         for( ; i_count--; p_xpixmap_format++ )
 418         {
 419             if( p_xpixmap_format->bits_per_pixel / 8 > p_vout->i_bytes_per_pixel )
 420             {
 421                 p_vout->i_bytes_per_pixel = p_xpixmap_format->bits_per_pixel / 8;
 422             }
 423         }
 424         break;
 425     }
 426     p_vout->p_sys->p_visual = p_xvisual->visual;
 427     XFree( p_xvisual );
 428
 429     /* Create a window */
 430     if( X11CreateWindow( p_vout ) )
 431     {
 432         intf_ErrMsg("error: can't open a window\n");
 433         XCloseDisplay( p_vout->p_sys->p_display );
 434         return( 1 );
 435     }
 436     return( 0 );
 437 }
 438
 439 /*****************************************************************************
 440  * X11CloseDisplay: close X11 device
 441  *****************************************************************************
 442  * Returns all resources allocated by X11OpenDisplay and restore the original
 443  * state of the display.
 444  *****************************************************************************/
 445 static void X11CloseDisplay( vout_thread_t *p_vout )
 446 {
 447     /* Destroy colormap */
 448     if( p_vout->i_screen_depth == 8 )
 449     {
 450         XFreeColormap( p_vout->p_sys->p_display, p_vout->p_sys->colormap );
 451     }
 452
 453     /* Destroy window */
 454     X11DestroyWindow( p_vout );
 455
 456     /* FIXME: We should close the display here, but X returns an error. */
 457     //XCloseDisplay( p_vout->p_sys->p_display );
 458 }
 459
 460 /*****************************************************************************
 461  * X11CreateWindow: create X11 vout window
 462  *****************************************************************************
 463  * The video output window will be created. Normally, this window is wether
 464  * full screen or part of a parent window. Therefore, it does not need a
 465  * title or other hints. Thery are still supplied in case the window would be
 466  * spawned as a standalone one by the interface.
 467  *****************************************************************************/
 468 static int X11CreateWindow( vout_thread_t *p_vout )
 469 {
 470     XSetWindowAttributes    xwindow_attributes;         /* window attributes */
 471     XGCValues               xgcvalues;      /* graphic context configuration */
 472     XEvent                  xevent;                          /* first events */
 473     boolean_t               b_expose;             /* 'expose' event received */
 474     boolean_t               b_map_notify;     /* 'map_notify' event received */
 475
 476     /* Prepare window attributes */
 477     xwindow_attributes.backing_store = Always;       /* save the hidden part */
 478
 479     /* Create the window and set hints */
 480     p_vout->p_sys->window = XCreateSimpleWindow( p_vout->p_sys->p_display,
 481                                          p_vout->p_sys->root_window,
 482                                          0, 0,
 483                                          p_vout->i_width, p_vout->i_height,
 484                                          0, 0, 0);
 485     XSelectInput( p_vout->p_sys->p_display, p_vout->p_sys->window,
 486                   ExposureMask | StructureNotifyMask );
 487     XChangeWindowAttributes( p_vout->p_sys->p_display, p_vout->p_sys->window,
 488                              CWBackingStore, &xwindow_attributes);
 489
 490     /* Creation of a graphic context that doesn't generate a GraphicsExpose event
 491        when using functions like XCopyArea */
 492     xgcvalues.graphics_exposures = False;
 493     p_vout->p_sys->gc =  XCreateGC( p_vout->p_sys->p_display, p_vout->p_sys->window,
 494                                     GCGraphicsExposures, &xgcvalues);
 495
 496     /* Send orders to server, and wait until window is displayed - two events
 497      * must be received: a MapNotify event, an Expose event allowing drawing in the
 498      * window */
 499     b_expose = 0;
 500     b_map_notify = 0;
 501     XMapWindow( p_vout->p_sys->p_display, p_vout->p_sys->window);
 502     do
 503     {
 504         XNextEvent( p_vout->p_sys->p_display, &xevent);
 505         if( (xevent.type == Expose)
 506             && (xevent.xexpose.window == p_vout->p_sys->window) )
 507         {
 508             b_expose = 1;
 509         }
 510         else if( (xevent.type == MapNotify)
 511                  && (xevent.xmap.window == p_vout->p_sys->window) )
 512         {
 513             b_map_notify = 1;
 514         }
 515     }
 516     while( !( b_expose && b_map_notify ) );
 517     XSelectInput( p_vout->p_sys->p_display, p_vout->p_sys->window, 0 );
 518
 519     /* At this stage, the window is open, displayed, and ready to receive
 520      * data */
 521     return( 0 );
 522 }
 523
 524 /*****************************************************************************
 525  * X11DestroyWindow: destroy X11 window
 526  *****************************************************************************
 527  * Destroy an X11 window created by vout_CreateWindow
 528  *****************************************************************************/
 529 static void X11DestroyWindow( vout_thread_t *p_vout )
 530 {
 531     XUnmapWindow( p_vout->p_sys->p_display, p_vout->p_sys->window );
 532     XFreeGC( p_vout->p_sys->p_display, p_vout->p_sys->gc );
 533     XDestroyWindow( p_vout->p_sys->p_display, p_vout->p_sys->window );
 534 }
 535
 536 /*****************************************************************************
 537  * X11CreateImage: create an XImage
 538  *****************************************************************************
 539  * Create a simple XImage used as a buffer.
 540  *****************************************************************************/
 541 static int X11CreateImage( vout_thread_t *p_vout, XImage **pp_ximage )
 542 {
 543     byte_t *    pb_data;                          /* image data storage zone */
 544     int         i_quantum;                     /* XImage quantum (see below) */
 545
 546     /* Allocate memory for image */
 547     p_vout->i_bytes_per_line = p_vout->i_width * p_vout->i_bytes_per_pixel;
 548     pb_data = (byte_t *) malloc( p_vout->i_bytes_per_line * p_vout->i_height );
 549     if( !pb_data )                                                  /* error */
 550     {
 551         intf_ErrMsg("error: %s\n", strerror(ENOMEM));
 552         return( 1 );
 553     }
 554
 555     /* Optimize the quantum of a scanline regarding its size - the quantum is
 556        a diviser of the number of bits between the start of two scanlines. */
 557     if( !(( p_vout->i_bytes_per_line ) % 32) )
 558     {
 559         i_quantum = 32;
 560     }
 561     else
 562     {
 563         if( !(( p_vout->i_bytes_per_line ) % 16) )
 564         {
 565             i_quantum = 16;
 566         }
 567         else
 568         {
 569             i_quantum = 8;
 570         }
 571     }
 572
 573     /* Create XImage */
 574     *pp_ximage = XCreateImage( p_vout->p_sys->p_display, p_vout->p_sys->p_visual,
 575                                p_vout->i_screen_depth, ZPixmap, 0, pb_data,
 576                                p_vout->i_width, p_vout->i_height, i_quantum, 0);
 577     if(! *pp_ximage )                                               /* error */
 578     {
 579         intf_ErrMsg( "error: XCreateImage() failed\n" );
 580         free( pb_data );
 581         return( 1 );
 582     }
 583
 584     return 0;
 585 }
 586
 587 /*****************************************************************************
 588  * X11CreateShmImage: create an XImage using shared memory extension
 589  *****************************************************************************
 590  * Prepare an XImage for DisplayX11ShmImage function.
 591  * The order of the operations respects the recommandations of the mit-shm
 592  * document by J.Corbet and K.Packard. Most of the parameters were copied from
 593  * there.
 594  *****************************************************************************/
 595 static int X11CreateShmImage( vout_thread_t *p_vout, XImage **pp_ximage,
 596                               XShmSegmentInfo *p_shm_info)
 597 {
 598     /* Create XImage */
 599     *pp_ximage = XShmCreateImage( p_vout->p_sys->p_display, p_vout->p_sys->p_visual,
 600                                   p_vout->i_screen_depth, ZPixmap, 0,
 601                                   p_shm_info, p_vout->i_width, p_vout->i_height );
 602     if(! *pp_ximage )                                               /* error */
 603     {
 604         intf_ErrMsg("error: XShmCreateImage() failed\n");
 605         return( 1 );
 606     }
 607
 608     /* Allocate shared memory segment - 0777 set the access permission
 609      * rights (like umask), they are not yet supported by X servers */
 610     p_shm_info->shmid = shmget( IPC_PRIVATE,
 611                                 (*pp_ximage)->bytes_per_line * (*pp_ximage)->height,
 612                                 IPC_CREAT | 0777);
 613     if( p_shm_info->shmid < 0)                                      /* error */
 614     {
 615         intf_ErrMsg("error: can't allocate shared image data (%s)\n",
 616                     strerror(errno));
 617         XDestroyImage( *pp_ximage );
 618         return( 1 );
 619     }
 620
 621     /* Attach shared memory segment to process (read/write) */
 622     p_shm_info->shmaddr = (*pp_ximage)->data = shmat(p_shm_info->shmid, 0, 0);
 623     if(! p_shm_info->shmaddr )
 624     {                                                               /* error */
 625         intf_ErrMsg("error: can't attach shared memory (%s)\n",
 626                     strerror(errno));
 627         shmctl( p_shm_info->shmid, IPC_RMID, 0 );      /* free shared memory */
 628         XDestroyImage( *pp_ximage );
 629         return( 1 );
 630     }
 631
 632     /* Mark the shm segment to be removed when there will be no more
 633      * attachements, so it is automatic on process exit or after shmdt */
 634     shmctl( p_shm_info->shmid, IPC_RMID, 0 );
 635
 636     /* Attach shared memory segment to X server (read only) */
 637     p_shm_info->readOnly = True;
 638     if( XShmAttach( p_vout->p_sys->p_display, p_shm_info ) == False )    /* error */
 639     {
 640         intf_ErrMsg("error: can't attach shared memory to X11 server\n");
 641         shmdt( p_shm_info->shmaddr );     /* detach shared memory from process
 642                                            * and automatic free                */
 643         XDestroyImage( *pp_ximage );
 644         return( 1 );
 645     }
 646
 647     /* Send image to X server. This instruction is required, since having
 648      * built a Shm XImage and not using it causes an error on XCloseDisplay */
 649     XFlush( p_vout->p_sys->p_display );
 650     return( 0 );
 651 }
 652
 653 /*****************************************************************************
 654  * X11DestroyImage: destroy an XImage
 655  *****************************************************************************
 656  * Destroy XImage AND associated data. If pointer is NULL, the image won't be
 657  * destroyed (see vout_ManageOutputMethod())
 658  *****************************************************************************/
 659 static void X11DestroyImage( XImage *p_ximage )
 660 {
 661     if( p_ximage != NULL )
 662     {
 663         XDestroyImage( p_ximage );                     /* no free() required */
 664     }
 665 }
 666
 667 /*****************************************************************************
 668  * X11DestroyShmImage
 669  *****************************************************************************
 670  * Destroy XImage AND associated data. Detach shared memory segment from
 671  * server and process, then free it. If pointer is NULL, the image won't be
 672  * destroyed (see vout_ManageOutputMethod())
 673  *****************************************************************************/
 674 static void X11DestroyShmImage( vout_thread_t *p_vout, XImage *p_ximage,
 675                                 XShmSegmentInfo *p_shm_info )
 676 {
 677     /* If pointer is NULL, do nothing */
 678     if( p_ximage == NULL )
 679     {
 680         return;
 681     }
 682
 683     XShmDetach( p_vout->p_sys->p_display, p_shm_info );     /* detach from server */
 684     XDestroyImage( p_ximage );
 685     if( shmdt( p_shm_info->shmaddr ) )  /* detach shared memory from process */
 686     {                                   /* also automatic freeing...         */
 687         intf_ErrMsg( "error: can't detach shared memory (%s)\n",
 688                      strerror(errno) );
 689     }
 690 }
 691
 692