examples: win32-videooverlay: Add support for testing gst_video_overlay_set_render_rectangle

Add keyboard handler to test gst_video_overlay_set_render_rectangle()
API for Windows video elements

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1235>

tests/examples/overlay/win32-videooverlay.c

@@ -36,11 +36,28 @@ static HWND hwnd = NULL;
 static gboolean test_fullscreen = FALSE;
 static gboolean fullscreen = FALSE;
 static gchar *video_sink = NULL;
+static GstElement *sink = NULL;
 static gboolean run_thread = FALSE;
 
 static LONG prev_style = 0;
 static RECT prev_rect = { 0, };
 
+static gint x = 0;
+static gint y = 0;
+static gint width = 320;
+static gint height = 240;
+
+typedef struct
+{
+  GThread *thread;
+  HANDLE event_handle;
+  HANDLE console_handle;
+  gboolean closing;
+  GMutex lock;
+} Win32KeyHandler;
+
+static Win32KeyHandler *win32_key_handler = NULL;
+
 #define DEFAULT_VIDEO_SINK "d3d11videosink"
 
 static gboolean
@@ -218,7 +235,7 @@ timeout_cb (gpointer user_data)
 static gpointer
 pipeline_runner_func (gpointer user_data)
 {
-  GstElement *pipeline, *src, *sink;
+  GstElement *pipeline, *src;
   GstStateChangeReturn sret;
   gint num_repeat = 0;
   GMainContext *context = NULL;
@@ -246,6 +263,8 @@ pipeline_runner_func (gpointer user_data)
     exit (1);
   }
 
+  gst_object_ref_sink (sink);
+
   gst_bin_add_many (GST_BIN (pipeline), src, sink, NULL);
   gst_element_link (src, sink);
 
@@ -293,6 +312,161 @@ pipeline_runner_func (gpointer user_data)
   return NULL;
 }
 
+static void
+print_keyboard_help (void)
+{
+  /* *INDENT-OFF* */
+  static struct
+  {
+    const gchar *key_desc;
+    const gchar *key_help;
+  } key_controls[] = {
+    {
+      "\342\206\222", "move overlay to right-hand side"}, {
+      "\342\206\220", "move overlay to left-hand side"}, {
+      "\342\206\221", "move overlay to upward"}, {
+      "\342\206\223", "move overlay to downward"}, {
+      ">", "increase overlay width"}, {
+      "<", "decrease overlay width"}, {
+      "+", "increase overlay height"}, {
+      "-", "decrease overlay height"}, {
+      "r", "reset render rectangle"}, {
+      "e", "expose overlay"}, {
+      "k", "show keyboard shortcuts"},
+  };
+  /* *INDENT-ON* */
+
+  guint i, chars_to_pad, desc_len, max_desc_len = 0;
+
+  gst_print ("\n\n%s\n\n", "Interactive mode - keyboard controls:");
+
+  for (i = 0; i < G_N_ELEMENTS (key_controls); ++i) {
+    desc_len = g_utf8_strlen (key_controls[i].key_desc, -1);
+    max_desc_len = MAX (max_desc_len, desc_len);
+  }
+  ++max_desc_len;
+
+  for (i = 0; i < G_N_ELEMENTS (key_controls); ++i) {
+    chars_to_pad = max_desc_len - g_utf8_strlen (key_controls[i].key_desc, -1);
+    gst_print ("\t%s", key_controls[i].key_desc);
+    gst_print ("%-*s: ", chars_to_pad, "");
+    gst_print ("%s\n", key_controls[i].key_help);
+  }
+  gst_print ("\n");
+}
+
+static gboolean
+win32_kb_source_cb (Win32KeyHandler * handler)
+{
+  HANDLE h_input = handler->console_handle;
+  INPUT_RECORD buffer;
+  DWORD n;
+
+  if (PeekConsoleInput (h_input, &buffer, 1, &n) && n == 1) {
+    ReadConsoleInput (h_input, &buffer, 1, &n);
+
+    if (buffer.EventType == KEY_EVENT && buffer.Event.KeyEvent.bKeyDown) {
+      gchar key_val[2] = { 0 };
+
+      switch (buffer.Event.KeyEvent.wVirtualKeyCode) {
+        case VK_RIGHT:
+          gst_println ("Move xpos to %d", x++);
+          gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+              x, y, width, height);
+          break;
+        case VK_LEFT:
+          gst_println ("Move xpos to %d", x--);
+          gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+              x, y, width, height);
+          break;
+        case VK_UP:
+          gst_println ("Move ypos to %d", y--);
+          gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+              x, y, width, height);
+          break;
+        case VK_DOWN:
+          gst_println ("Move ypos to %d", y++);
+          gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+              x, y, width, height);
+          break;
+        default:
+          key_val[0] = buffer.Event.KeyEvent.uChar.AsciiChar;
+          switch (key_val[0]) {
+            case '<':
+              gst_println ("Decrease width to %d", width--);
+              gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+                  x, y, width, height);
+              break;
+            case '>':
+              gst_println ("Increase width to %d", width++);
+              gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+                  x, y, width, height);
+              break;
+            case '+':
+              gst_println ("Increase height to %d", height++);
+              gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+                  x, y, width, height);
+              break;
+            case '-':
+              gst_println ("Decrease height to %d", height--);
+              gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+                  x, y, width, height);
+              break;
+            case 'r':
+              gst_println ("Reset render rectangle by setting -1 width/height");
+              gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (sink),
+                  x, y, -1, -1);
+              break;
+            case 'e':
+              gst_println ("Expose overlay");
+              gst_video_overlay_expose (GST_VIDEO_OVERLAY (sink));
+              break;
+            case 'k':
+              print_keyboard_help ();
+              break;
+            default:
+              break;
+          }
+          break;
+      }
+    }
+  }
+
+  return G_SOURCE_REMOVE;
+}
+
+static gpointer
+win32_kb_thread (gpointer user_data)
+{
+  Win32KeyHandler *handler = (Win32KeyHandler *) user_data;
+  HANDLE handles[2];
+
+  handles[0] = handler->event_handle;
+  handles[1] = handler->console_handle;
+
+  while (TRUE) {
+    DWORD ret = WaitForMultipleObjects (2, handles, FALSE, INFINITE);
+    static guint i = 0;
+
+    if (ret == WAIT_FAILED) {
+      g_warning ("WaitForMultipleObject Failed");
+      return NULL;
+    }
+
+    g_mutex_lock (&handler->lock);
+    if (handler->closing) {
+      g_mutex_unlock (&handler->lock);
+
+      return NULL;
+    }
+    g_mutex_unlock (&handler->lock);
+
+    g_idle_add ((GSourceFunc) win32_kb_source_cb, handler);
+  }
+
+  return NULL;
+}
+
 gint
 main (gint argc, gchar ** argv)
 {
@@ -361,6 +535,25 @@ main (gint argc, gchar ** argv)
   msg_io_channel = g_io_channel_win32_new_messages (0);
   g_io_add_watch (msg_io_channel, G_IO_IN, msg_cb, NULL);
 
+  {
+    SECURITY_ATTRIBUTES attrs;
+
+    attrs.nLength = sizeof (SECURITY_ATTRIBUTES);
+    attrs.lpSecurityDescriptor = NULL;
+    attrs.bInheritHandle = FALSE;
+
+    win32_key_handler = g_new0 (Win32KeyHandler, 1);
+
+    /* create cancellable event handle */
+    win32_key_handler->event_handle = CreateEvent (&attrs, TRUE, FALSE, NULL);
+    win32_key_handler->console_handle = GetStdHandle (STD_INPUT_HANDLE);
+    g_mutex_init (&win32_key_handler->lock);
+    win32_key_handler->thread =
+        g_thread_new ("key-handler", win32_kb_thread, win32_key_handler);
+  }
+
+  gst_println ("Press 'k' to see a list of keyboard shortcuts");
+
   if (run_thread) {
     thread = g_thread_new ("pipeline-thread",
         (GThreadFunc) pipeline_runner_func, NULL);
@@ -373,6 +566,20 @@ terminate:
   if (hwnd)
     DestroyWindow (hwnd);
 
+  if (win32_key_handler) {
+    g_mutex_lock (&win32_key_handler->lock);
+    win32_key_handler->closing = TRUE;
+    g_mutex_unlock (&win32_key_handler->lock);
+
+    SetEvent (win32_key_handler->event_handle);
+    g_thread_join (win32_key_handler->thread);
+    CloseHandle (win32_key_handler->event_handle);
+
+    g_mutex_clear (&win32_key_handler->lock);
+    g_free (win32_key_handler);
+  }
+
+  gst_clear_object (&sink);
   g_io_channel_unref (msg_io_channel);
   g_main_loop_unref (loop);
   g_free (title);