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 program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, 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", 70)
  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     if (cfg->type != VOUT_WINDOW_TYPE_INVALID
  71      && cfg->type != VOUT_WINDOW_TYPE_HWND)
  72         return VLC_EGENERIC;
  73
  74     uintptr_t val = var_InheritInteger (wnd, "drawable-hwnd");
  75     if (val == 0)
  76         return VLC_EGENERIC;
  77
  78     uintptr_t *tab;
  79     size_t n = 0;
  80
  81     vlc_mutex_lock (&serializer);
  82     if (used != NULL)
  83         for (/*n = 0*/; used[n]; n++)
  84             if (used[n] == val)
  85             {
  86                 msg_Warn (wnd, "HWND 0x%zX is busy", val);
  87                 val = 0;
  88                 goto skip;
  89             }
  90
  91     tab = realloc (used, sizeof (*used) * (n + 2));
  92     if (likely(tab != NULL))
  93     {
  94         used = tab;
  95         used[n] = val;
  96         used[n + 1] = 0;
  97     }
  98     else
  99         val = 0;
 100 skip:
 101     vlc_mutex_unlock (&serializer);
 102
 103     if (val == 0)
 104         return VLC_EGENERIC;
 105
 106     wnd->type = VOUT_WINDOW_TYPE_HWND;
 107     wnd->handle.hwnd = (void *)val;
 108     wnd->control = Control;
 109     wnd->sys = (void *)val;
 110     return VLC_SUCCESS;
 111 }
 112
 113 /**
 114  * Release the drawable.
 115  */
 116 static void Close (vout_window_t *wnd)
 117 {
 118     uintptr_t val = (uintptr_t)wnd->sys;
 119     size_t n = 0;
 120
 121     /* Remove this drawable from the list of busy ones */
 122     vlc_mutex_lock (&serializer);
 123     assert (used != NULL);
 124     while (used[n] != val)
 125     {
 126         assert (used[n]);
 127         n++;
 128     }
 129     do
 130         used[n] = used[n + 1];
 131     while (used[++n] != 0);
 132
 133     if (n == 0)
 134     {
 135          free (used);
 136          used = NULL;
 137     }
 138     vlc_mutex_unlock (&serializer);
 139 }
 140
 141
 142 static int Control (vout_window_t *wnd, int query, va_list ap)
 143 {
 144     VLC_UNUSED( ap );
 145
 146     switch (query)
 147     {
 148         case VOUT_WINDOW_SET_SIZE:   /* not allowed */
 149         case VOUT_WINDOW_SET_STATE: /* not allowed either, would be ugly */
 150             return VLC_EGENERIC;
 151         default:
 152             msg_Warn (wnd, "unsupported control query %d", query);
 153             return VLC_EGENERIC;
 154     }
 155 }