window: add toplevel API to determine a visual id.

Add GstVaapiWindowClass::get_visual_id() function hook to help find
the best suitable visual id for the supplied window. While doing so,
also simplify the process by which an X11 window is created with a
desired Visual, i.e. now use a visual id instead of a Visual object.

gst-libs/gst/vaapi/gstvaapiutils_x11.c

@@ -68,18 +68,18 @@ static const int x11_event_mask =
  * @dpy: an X11 #Display
  * @w: the requested width, in pixels
  * @h: the requested height, in pixels
- * @vis: the request visual
- * @cmap: the request colormap
+ * @vid: the requested visual id
+ * @cmap: the requested colormap
  *
- * Creates a border-less window with the specified dimensions. If @vis
- * is %NULL, the default visual for @display will be used. If @cmap is
+ * Creates a border-less window with the specified dimensions. If @vid
+ * is zero, the default visual for @display will be used. If @cmap is
  * %None, no specific colormap will be bound to the window. Also note
  * the default background color is black.
  *
  * Return value: the newly created X #Window.
  */
 Window
-x11_create_window (Display * dpy, guint w, guint h, Visual * vis, Colormap cmap)
+x11_create_window (Display * dpy, guint w, guint h, guint vid, Colormap cmap)
 {
   Window rootwin, win;
   int screen, depth;
@@ -87,14 +87,13 @@ x11_create_window (Display * dpy, guint w, guint h, Visual * vis, Colormap cmap)
   unsigned long xswa_mask;
   XWindowAttributes wattr;
   unsigned long black_pixel;
+  XVisualInfo visualInfo, *vi;
+  int num_visuals;
 
   screen = DefaultScreen (dpy);
   rootwin = RootWindow (dpy, screen);
   black_pixel = BlackPixel (dpy, screen);
 
-  if (!vis)
-    vis = DefaultVisual (dpy, screen);
-
   XGetWindowAttributes (dpy, rootwin, &wattr);
   depth = wattr.depth;
   if (depth != 15 && depth != 16 && depth != 24 && depth != 32)
@@ -109,13 +108,35 @@ x11_create_window (Display * dpy, guint w, guint h, Visual * vis, Colormap cmap)
     xswa.colormap = cmap;
   }
 
-  win = XCreateWindow (dpy, rootwin, 0, 0, w, h, 0, depth, InputOutput, vis,
-      xswa_mask, &xswa);
+  if (vid) {
+    visualInfo.visualid = vid;
+    vi = XGetVisualInfo (dpy, VisualIDMask, &visualInfo, &num_visuals);
+    if (!vi || num_visuals < 1)
+      goto error_create_visual;
+  } else {
+    vi = &visualInfo;
+    XMatchVisualInfo (dpy, screen, depth, TrueColor, vi);
+  }
+
+  win = XCreateWindow (dpy, rootwin, 0, 0, w, h, 0, depth, InputOutput,
+      vi->visual, xswa_mask, &xswa);
+  if (vi != &visualInfo)
+    XFree (vi);
   if (!win)
-    return None;
+    goto error_create_window;
 
   XSelectInput (dpy, win, x11_event_mask);
   return win;
+
+  /* ERRORS */
+error_create_visual:
+  GST_ERROR ("failed to create X visual (id:%zu)", (gsize) visualInfo.visualid);
+  if (vi)
+    XFree (vi);
+  return None;
+error_create_window:
+  GST_ERROR ("failed to create X window of size %ux%u", w, h);
+  return None;
 }
 
 gboolean

gst-libs/gst/vaapi/gstvaapiutils_x11.h

@@ -40,8 +40,7 @@ x11_untrap_errors (void);
 
 G_GNUC_INTERNAL
 Window
-x11_create_window (Display * dpy, guint w, guint h, Visual * vis,
-    Colormap cmap);
+x11_create_window (Display * dpy, guint w, guint h, guint vid, Colormap cmap);
 
 G_GNUC_INTERNAL
 gboolean

gst-libs/gst/vaapi/gstvaapiwindow_glx.c

@@ -206,15 +206,15 @@ gst_vaapi_window_glx_ensure_context (GstVaapiWindow * window,
   return TRUE;
 }
 
-static Visual *
-gst_vaapi_window_glx_get_visual (GstVaapiWindow * window)
+static guintptr
+gst_vaapi_window_glx_get_visual_id (GstVaapiWindow * window)
 {
   GstVaapiWindowGLXPrivate *const priv =
       GST_VAAPI_WINDOW_GLX_GET_PRIVATE (window);
 
   if (!_gst_vaapi_window_glx_ensure_context (window, NULL))
-    return NULL;
-  return priv->gl_context->visual->visual;
+    return 0;
+  return priv->gl_context->visual->visualid;
 }
 
 static void
@@ -320,7 +320,7 @@ gst_vaapi_window_glx_class_init (GstVaapiWindowGLXClass * klass)
   klass->parent_resize = window_class->resize;
   klass->parent_finalize = GST_VAAPI_OBJECT_CLASS (klass)->finalize;
   window_class->resize = gst_vaapi_window_glx_resize;
-  xwindow_class->get_visual = gst_vaapi_window_glx_get_visual;
+  window_class->get_visual_id = gst_vaapi_window_glx_get_visual_id;
   xwindow_class->get_colormap = gst_vaapi_window_glx_get_colormap;
 }
 

gst-libs/gst/vaapi/gstvaapiwindow_priv.h

@@ -52,6 +52,7 @@ typedef gboolean (*GstVaapiWindowRenderFunc) (GstVaapiWindow * window,
 typedef gboolean (*GstVaapiWindowRenderPixmapFunc) (GstVaapiWindow * window,
     GstVaapiPixmap * pixmap, const GstVaapiRectangle * src_rect,
     const GstVaapiRectangle * dst_rect);
+typedef guintptr (*GstVaapiWindowGetVisualIdFunc) (GstVaapiWindow * window);
 
 /**
  * GstVaapiWindow:
@@ -82,6 +83,8 @@ struct _GstVaapiWindow
  * @set_fullscreen: virtual function to change window fullscreen state
  * @resize: virtual function to resize a window
  * @render: virtual function to render a #GstVaapiSurface into a window
+ * @get_visual_id: virtual function to get the desired visual id used to
+ *   create the window
  *
  * Base class for system-dependent windows.
  */
@@ -99,6 +102,7 @@ struct _GstVaapiWindowClass
   GstVaapiWindowResizeFunc resize;
   GstVaapiWindowRenderFunc render;
   GstVaapiWindowRenderPixmapFunc render_pixmap;
+  GstVaapiWindowGetVisualIdFunc get_visual_id;
 };
 
 GstVaapiWindow *

gst-libs/gst/vaapi/gstvaapiwindow_x11.c

@@ -214,8 +214,9 @@ gst_vaapi_window_x11_create (GstVaapiWindow * window, guint * width,
       GST_VAAPI_WINDOW_X11_GET_PRIVATE (window);
   Display *const dpy = GST_VAAPI_OBJECT_NATIVE_DISPLAY (window);
   Window xid = GST_VAAPI_OBJECT_ID (window);
-  Visual *vis = NULL;
+  guint vid = 0;
   Colormap cmap = None;
+  const GstVaapiWindowClass *window_class;
   const GstVaapiWindowX11Class *klass;
   XWindowAttributes wattr;
   Atom atoms[2];
@@ -238,10 +239,14 @@ gst_vaapi_window_x11_create (GstVaapiWindow * window, guint * width,
     return ok;
   }
 
+  window_class = GST_VAAPI_WINDOW_GET_CLASS (window);
+  if (window_class) {
+    if (window_class->get_visual_id)
+      vid = window_class->get_visual_id (window);
+  }
+
   klass = GST_VAAPI_WINDOW_X11_GET_CLASS (window);
   if (klass) {
-    if (klass->get_visual)
-      vis = klass->get_visual (window);
     if (klass->get_colormap)
       cmap = klass->get_colormap (window);
   }
@@ -252,7 +257,7 @@ gst_vaapi_window_x11_create (GstVaapiWindow * window, guint * width,
   priv->atom_NET_WM_STATE = atoms[0];
   priv->atom_NET_WM_STATE_FULLSCREEN = atoms[1];
 
-  xid = x11_create_window (dpy, *width, *height, vis, cmap);
+  xid = x11_create_window (dpy, *width, *height, vid, cmap);
   if (xid)
     XRaiseWindow (dpy, xid);
   GST_VAAPI_OBJECT_UNLOCK_DISPLAY (window);

gst-libs/gst/vaapi/gstvaapiwindow_x11_priv.h

@@ -72,8 +72,6 @@ struct _GstVaapiWindowX11
 
 /**
  * GstVaapiWindowX11Class:
- * @get_visual: virtual function to get the desired visual used to
- *   create the window
  * @get_colormap: virtual function to get the desired colormap used to
  *   create the window
  *
@@ -84,7 +82,6 @@ struct _GstVaapiWindowX11Class
   /*< private >*/
   GstVaapiWindowClass parent_class;
 
-  Visual *(*get_visual) (GstVaapiWindow * window);
   Colormap (*get_colormap) (GstVaapiWindow * window);
 };