modules/video_output/drawable.c

   1 /**
   2  * @file drawable.c
   3  * @brief Legacy monolithic LibVLC video window provider
   4  */
   5 /*****************************************************************************
   6  * Copyright © 2009 Rémi Denis-Courmont
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This library 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
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  ****************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 #include <stdarg.h>
  28 #include <assert.h>
  29
  30 #include <vlc_common.h>
  31 #include <vlc_plugin.h>
  32 #include <vlc_vout_window.h>
  33
  34 static int  Open (vlc_object_t *);
  35 static void Close(vlc_object_t *);
  36
  37 /*
  38  * Module descriptor
  39  */
  40 vlc_module_begin ()
  41     set_shortname (N_("Drawable"))
  42     set_description (N_("Embedded window video"))
  43     set_category (CAT_VIDEO)
  44     set_subcategory (SUBCAT_VIDEO_VOUT)
  45     set_capability ("vout window hwnd", 0)
  46     set_callbacks (Open, Close)
  47     add_shortcut ("embed-hwnd")
  48 vlc_module_end ()
  49
  50 static int Control (vout_window_t *, int, va_list);
  51
  52 static vlc_mutex_t serializer = VLC_STATIC_MUTEX;
  53
  54 /**
  55  * Find the drawable set by libvlc application.
  56  */
  57 static int Open (vlc_object_t *obj)
  58 {
  59     vout_window_t *wnd = (vout_window_t *)obj;
  60     void **used, *val;
  61     size_t n = 0;
  62
  63     if (var_Create (obj->p_libvlc, "hwnd-in-use", VLC_VAR_ADDRESS)
  64      || var_Create (obj, "drawable-hwnd", VLC_VAR_DOINHERIT | VLC_VAR_ADDRESS))
  65         return VLC_ENOMEM;
  66
  67     val = var_GetAddress (obj, "drawable-hwnd");
  68     var_Destroy (obj, "drawable-hwnd");
  69
  70     /* Keep a list of busy drawables, so we don't overlap videos if there are
  71      * more than one video track in the stream. */
  72     vlc_mutex_lock (&serializer);
  73     used = var_GetAddress (obj->p_libvlc, "hwnd-in-use");
  74     if (used != NULL)
  75     {
  76         while (used[n] != NULL)
  77         {
  78             if (used[n] == val)
  79                 goto skip;
  80             n++;
  81         }
  82     }
  83
  84     used = realloc (used, sizeof (*used) * (n + 2));
  85     if (used != NULL)
  86     {
  87         used[n] = val;
  88         used[n + 1] = NULL;
  89         var_SetAddress (obj->p_libvlc, "hwnd-in-use", used);
  90     }
  91     else
  92     {
  93 skip:
  94         msg_Warn (wnd, "HWND %p is busy", val);
  95         val = NULL;
  96     }
  97     vlc_mutex_unlock (&serializer);
  98
  99     if (val == NULL)
 100         return VLC_EGENERIC;
 101
 102     wnd->handle.hwnd = val;
 103     wnd->control = Control;
 104     wnd->sys = val;
 105     return VLC_SUCCESS;
 106 }
 107
 108 /**
 109  * Release the drawable.
 110  */
 111 static void Close (vlc_object_t *obj)
 112 {
 113     vout_window_t *wnd = (vout_window_t *)obj;
 114     void **used, *val = wnd->sys;
 115     size_t n = 0;
 116
 117     /* Remove this drawable from the list of busy ones */
 118     vlc_mutex_lock (&serializer);
 119     used = var_GetAddress (obj->p_libvlc, "hwnd-in-use");
 120     assert (used);
 121     while (used[n] != val)
 122     {
 123         assert (used[n]);
 124         n++;
 125     }
 126     do
 127         used[n] = used[n + 1];
 128     while (used[++n] != NULL);
 129
 130     if (n == 0)
 131          var_SetAddress (obj->p_libvlc, "hwnd-in-use", NULL);
 132     vlc_mutex_unlock (&serializer);
 133
 134     if (n == 0)
 135         free (used);
 136     /* Variables are reference-counted... */
 137     var_Destroy (obj->p_libvlc, "hwnd-in-use");
 138 }
 139
 140
 141 static int Control (vout_window_t *wnd, int query, va_list ap)
 142 {
 143     VLC_UNUSED( ap );
 144
 145     switch (query)
 146     {
 147         case VOUT_WINDOW_SET_SIZE:   /* not allowed */
 148         case VOUT_WINDOW_SET_STATE: /* not allowed either, would be ugly */
 149             return VLC_EGENERIC;
 150         default:
 151             msg_Warn (wnd, "unsupported control query %d", query);
 152             return VLC_EGENERIC;
 153     }
 154 }
 155