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 #define HWND_TEXT N_("Window handle (HWND)")
  35 #define HWND_LONGTEXT N_( \
  36     "Video will be embedded in this pre-existing window. " \
  37     "If zero, a new window will be created.")
  38
  39 static int  Open (vout_window_t *, const vout_window_cfg_t *);
  40 static void Close(vout_window_t *);
  41
  42 /*
  43  * Module descriptor
  44  */
  45 vlc_module_begin ()
  46     set_shortname (N_("Drawable"))
  47     set_description (N_("Embedded window video"))
  48     set_category (CAT_VIDEO)
  49     set_subcategory (SUBCAT_VIDEO_VOUT)
  50     set_capability ("vout window hwnd", 0)
  51     set_callbacks (Open, Close)
  52     add_shortcut ("embed-hwnd")
  53
  54     add_integer ("drawable-hwnd", 0, HWND_TEXT, HWND_LONGTEXT, true)
  55         change_volatile ()
  56 vlc_module_end ()
  57
  58 static int Control (vout_window_t *, int, va_list);
  59
  60 /* Keep a list of busy drawables, so we don't overlap videos if there are
  61  * more than one video track in the stream. */
  62 static vlc_mutex_t serializer = VLC_STATIC_MUTEX;
  63 static uintptr_t *used = NULL;
  64
  65 /**
  66  * Find the drawable set by libvlc application.
  67  */
  68 static int Open (vout_window_t *wnd, const vout_window_cfg_t *cfg)
  69 {
  70     VLC_UNUSED (cfg);
  71     uintptr_t val = var_InheritInteger (wnd, "drawable-hwnd");
  72     if (val == 0)
  73         return VLC_EGENERIC;
  74
  75     uintptr_t *tab;
  76     size_t n = 0;
  77
  78     vlc_mutex_lock (&serializer);
  79     if (used != NULL)
  80         for (/*n = 0*/; used[n]; n++)
  81             if (used[n] == val)
  82             {
  83                 msg_Warn (wnd, "HWND 0x%zX is busy", val);
  84                 val = 0;
  85                 goto skip;
  86             }
  87
  88     tab = realloc (used, sizeof (*used) * (n + 2));
  89     if (likely(tab != NULL))
  90     {
  91         used = tab;
  92         used[n] = val;
  93         used[n + 1] = 0;
  94     }
  95     else
  96         val = 0;
  97 skip:
  98     vlc_mutex_unlock (&serializer);
  99
 100     if (val == 0)
 101         return VLC_EGENERIC;
 102
 103     wnd->handle.hwnd = (void *)val;
 104     wnd->control = Control;
 105     wnd->sys = (void *)val;
 106     return VLC_SUCCESS;
 107 }
 108
 109 /**
 110  * Release the drawable.
 111  */
 112 static void Close (vout_window_t *wnd)
 113 {
 114     uintptr_t val = (uintptr_t)wnd->sys;
 115     size_t n = 0;
 116
 117     /* Remove this drawable from the list of busy ones */
 118     vlc_mutex_lock (&serializer);
 119     assert (used != NULL);
 120     while (used[n] != val)
 121     {
 122         assert (used[n]);
 123         n++;
 124     }
 125     do
 126         used[n] = used[n + 1];
 127     while (used[++n] != 0);
 128
 129     if (n == 0)
 130     {
 131          free (used);
 132          used = NULL;
 133     }
 134     vlc_mutex_unlock (&serializer);
 135 }
 136
 137
 138 static int Control (vout_window_t *wnd, int query, va_list ap)
 139 {
 140     VLC_UNUSED( ap );
 141
 142     switch (query)
 143     {
 144         case VOUT_WINDOW_SET_SIZE:   /* not allowed */
 145         case VOUT_WINDOW_SET_STATE: /* not allowed either, would be ugly */
 146             return VLC_EGENERIC;
 147         default:
 148             msg_Warn (wnd, "unsupported control query %d", query);
 149             return VLC_EGENERIC;
 150     }
 151 }