5 #include <gst/video/videooverlay.h>
8 #include <TargetConditionals.h>
12 #if defined (GDK_WINDOWING_X11)
14 #elif defined (GDK_WINDOWING_WIN32)
15 #include <gdk/gdkwin32.h>
16 #elif defined (GDK_WINDOWING_QUARTZ)
17 #include <gdk/gdkquartz.h>
18 #if GTK_CHECK_VERSION(3, 24, 10)
19 #include <AppKit/AppKit.h>
20 NSView *gdk_quartz_window_get_nsview (GdkWindow * window);
24 /* Structure to contain all our information, so we can pass it around */
25 typedef struct _CustomData
27 GstElement *playbin; /* Our one and only pipeline */
29 GtkWidget *slider; /* Slider widget to keep track of current position */
30 GtkWidget *streams_list; /* Text widget to display info about the streams */
31 gulong slider_update_signal_id; /* Signal ID for the slider update signal */
33 GstState state; /* Current state of the pipeline */
34 gint64 duration; /* Duration of the clip, in nanoseconds */
37 /* This function is called when the GUI toolkit creates the physical window that will hold the video.
38 * At this point we can retrieve its handler (which has a different meaning depending on the windowing system)
39 * and pass it to GStreamer through the XOverlay interface. */
41 realize_cb (GtkWidget * widget, CustomData * data)
43 GdkWindow *window = gtk_widget_get_window (widget);
44 guintptr window_handle;
46 if (!gdk_window_ensure_native (window))
47 g_error ("Couldn't create native window needed for GstXOverlay!");
49 /* Retrieve window handler from GDK */
50 #if defined (GDK_WINDOWING_WIN32)
51 window_handle = (guintptr) GDK_WINDOW_HWND (window);
52 #elif defined (GDK_WINDOWING_QUARTZ)
53 window_handle = gdk_quartz_window_get_nsview (window);
54 #elif defined (GDK_WINDOWING_X11)
55 window_handle = GDK_WINDOW_XID (window);
57 /* Pass it to playbin, which implements XOverlay and will forward it to the video sink */
58 gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (data->playbin),
62 /* This function is called when the PLAY button is clicked */
64 play_cb (GtkButton * button, CustomData * data)
66 gst_element_set_state (data->playbin, GST_STATE_PLAYING);
69 /* This function is called when the PAUSE button is clicked */
71 pause_cb (GtkButton * button, CustomData * data)
73 gst_element_set_state (data->playbin, GST_STATE_PAUSED);
76 /* This function is called when the STOP button is clicked */
78 stop_cb (GtkButton * button, CustomData * data)
80 gst_element_set_state (data->playbin, GST_STATE_READY);
83 /* This function is called when the main window is closed */
85 delete_event_cb (GtkWidget * widget, GdkEvent * event, CustomData * data)
91 /* This function is called everytime the video window needs to be redrawn (due to damage/exposure,
92 * rescaling, etc). GStreamer takes care of this in the PAUSED and PLAYING states, otherwise,
93 * we simply draw a black rectangle to avoid garbage showing up. */
95 draw_cb (GtkWidget * widget, cairo_t * cr, CustomData * data)
97 if (data->state < GST_STATE_PAUSED) {
98 GtkAllocation allocation;
100 /* Cairo is a 2D graphics library which we use here to clean the video window.
101 * It is used by GStreamer for other reasons, so it will always be available to us. */
102 gtk_widget_get_allocation (widget, &allocation);
103 cairo_set_source_rgb (cr, 0, 0, 0);
104 cairo_rectangle (cr, 0, 0, allocation.width, allocation.height);
111 /* This function is called when the slider changes its position. We perform a seek to the
112 * new position here. */
114 slider_cb (GtkRange * range, CustomData * data)
116 gdouble value = gtk_range_get_value (GTK_RANGE (data->slider));
117 gst_element_seek_simple (data->playbin, GST_FORMAT_TIME,
118 GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT,
119 (gint64) (value * GST_SECOND));
122 /* This creates all the GTK+ widgets that compose our application, and registers the callbacks */
124 create_ui (CustomData * data)
126 GtkWidget *main_window; /* The uppermost window, containing all other windows */
127 GtkWidget *video_window; /* The drawing area where the video will be shown */
128 GtkWidget *main_box; /* VBox to hold main_hbox and the controls */
129 GtkWidget *main_hbox; /* HBox to hold the video_window and the stream info text widget */
130 GtkWidget *controls; /* HBox to hold the buttons and the slider */
131 GtkWidget *play_button, *pause_button, *stop_button; /* Buttons */
133 main_window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
134 g_signal_connect (G_OBJECT (main_window), "delete-event",
135 G_CALLBACK (delete_event_cb), data);
137 video_window = gtk_drawing_area_new ();
138 gtk_widget_set_double_buffered (video_window, FALSE);
139 g_signal_connect (video_window, "realize", G_CALLBACK (realize_cb), data);
140 g_signal_connect (video_window, "draw", G_CALLBACK (draw_cb), data);
143 gtk_button_new_from_icon_name ("media-playback-start",
144 GTK_ICON_SIZE_SMALL_TOOLBAR);
145 g_signal_connect (G_OBJECT (play_button), "clicked", G_CALLBACK (play_cb),
149 gtk_button_new_from_icon_name ("media-playback-pause",
150 GTK_ICON_SIZE_SMALL_TOOLBAR);
151 g_signal_connect (G_OBJECT (pause_button), "clicked", G_CALLBACK (pause_cb),
155 gtk_button_new_from_icon_name ("media-playback-stop",
156 GTK_ICON_SIZE_SMALL_TOOLBAR);
157 g_signal_connect (G_OBJECT (stop_button), "clicked", G_CALLBACK (stop_cb),
161 gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
162 gtk_scale_set_draw_value (GTK_SCALE (data->slider), 0);
163 data->slider_update_signal_id =
164 g_signal_connect (G_OBJECT (data->slider), "value-changed",
165 G_CALLBACK (slider_cb), data);
167 data->streams_list = gtk_text_view_new ();
168 gtk_text_view_set_editable (GTK_TEXT_VIEW (data->streams_list), FALSE);
170 controls = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
171 gtk_box_pack_start (GTK_BOX (controls), play_button, FALSE, FALSE, 2);
172 gtk_box_pack_start (GTK_BOX (controls), pause_button, FALSE, FALSE, 2);
173 gtk_box_pack_start (GTK_BOX (controls), stop_button, FALSE, FALSE, 2);
174 gtk_box_pack_start (GTK_BOX (controls), data->slider, TRUE, TRUE, 2);
176 main_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
177 gtk_box_pack_start (GTK_BOX (main_hbox), video_window, TRUE, TRUE, 0);
178 gtk_box_pack_start (GTK_BOX (main_hbox), data->streams_list, FALSE, FALSE, 2);
180 main_box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
181 gtk_box_pack_start (GTK_BOX (main_box), main_hbox, TRUE, TRUE, 0);
182 gtk_box_pack_start (GTK_BOX (main_box), controls, FALSE, FALSE, 0);
183 gtk_container_add (GTK_CONTAINER (main_window), main_box);
184 gtk_window_set_default_size (GTK_WINDOW (main_window), 640, 480);
186 gtk_widget_show_all (main_window);
189 /* This function is called periodically to refresh the GUI */
191 refresh_ui (CustomData * data)
195 /* We do not want to update anything unless we are in the PAUSED or PLAYING states */
196 if (data->state < GST_STATE_PAUSED)
199 /* If we didn't know it yet, query the stream duration */
200 if (!GST_CLOCK_TIME_IS_VALID (data->duration)) {
201 if (!gst_element_query_duration (data->playbin, GST_FORMAT_TIME,
203 g_printerr ("Could not query current duration.\n");
205 /* Set the range of the slider to the clip duration, in SECONDS */
206 gtk_range_set_range (GTK_RANGE (data->slider), 0,
207 (gdouble) data->duration / GST_SECOND);
211 if (gst_element_query_position (data->playbin, GST_FORMAT_TIME, ¤t)) {
212 /* Block the "value-changed" signal, so the slider_cb function is not called
213 * (which would trigger a seek the user has not requested) */
214 g_signal_handler_block (data->slider, data->slider_update_signal_id);
215 /* Set the position of the slider to the current pipeline positoin, in SECONDS */
216 gtk_range_set_value (GTK_RANGE (data->slider),
217 (gdouble) current / GST_SECOND);
218 /* Re-enable the signal */
219 g_signal_handler_unblock (data->slider, data->slider_update_signal_id);
224 /* This function is called when new metadata is discovered in the stream */
226 tags_cb (GstElement * playbin, gint stream, CustomData * data)
228 /* We are possibly in a GStreamer working thread, so we notify the main
229 * thread of this event through a message in the bus */
230 gst_element_post_message (playbin,
231 gst_message_new_application (GST_OBJECT (playbin),
232 gst_structure_new_empty ("tags-changed")));
235 /* This function is called when an error message is posted on the bus */
237 error_cb (GstBus * bus, GstMessage * msg, CustomData * data)
242 /* Print error details on the screen */
243 gst_message_parse_error (msg, &err, &debug_info);
244 g_printerr ("Error received from element %s: %s\n",
245 GST_OBJECT_NAME (msg->src), err->message);
246 g_printerr ("Debugging information: %s\n", debug_info ? debug_info : "none");
247 g_clear_error (&err);
250 /* Set the pipeline to READY (which stops playback) */
251 gst_element_set_state (data->playbin, GST_STATE_READY);
254 /* This function is called when an End-Of-Stream message is posted on the bus.
255 * We just set the pipeline to READY (which stops playback) */
257 eos_cb (GstBus * bus, GstMessage * msg, CustomData * data)
259 g_print ("End-Of-Stream reached.\n");
260 gst_element_set_state (data->playbin, GST_STATE_READY);
263 /* This function is called when the pipeline changes states. We use it to
264 * keep track of the current state. */
266 state_changed_cb (GstBus * bus, GstMessage * msg, CustomData * data)
268 GstState old_state, new_state, pending_state;
269 gst_message_parse_state_changed (msg, &old_state, &new_state, &pending_state);
270 if (GST_MESSAGE_SRC (msg) == GST_OBJECT (data->playbin)) {
271 data->state = new_state;
272 g_print ("State set to %s\n", gst_element_state_get_name (new_state));
273 if (old_state == GST_STATE_READY && new_state == GST_STATE_PAUSED) {
274 /* For extra responsiveness, we refresh the GUI as soon as we reach the PAUSED state */
280 /* Extract metadata from all the streams and write it to the text widget in the GUI */
282 analyze_streams (CustomData * data)
286 gchar *str, *total_str;
288 gint n_video, n_audio, n_text;
291 /* Clean current contents of the widget */
292 text = gtk_text_view_get_buffer (GTK_TEXT_VIEW (data->streams_list));
293 gtk_text_buffer_set_text (text, "", -1);
295 /* Read some properties */
296 g_object_get (data->playbin, "n-video", &n_video, NULL);
297 g_object_get (data->playbin, "n-audio", &n_audio, NULL);
298 g_object_get (data->playbin, "n-text", &n_text, NULL);
300 for (i = 0; i < n_video; i++) {
302 /* Retrieve the stream's video tags */
303 g_signal_emit_by_name (data->playbin, "get-video-tags", i, &tags);
305 total_str = g_strdup_printf ("video stream %d:\n", i);
306 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
308 gst_tag_list_get_string (tags, GST_TAG_VIDEO_CODEC, &str);
309 total_str = g_strdup_printf (" codec: %s\n", str ? str : "unknown");
310 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
313 gst_tag_list_free (tags);
317 for (i = 0; i < n_audio; i++) {
319 /* Retrieve the stream's audio tags */
320 g_signal_emit_by_name (data->playbin, "get-audio-tags", i, &tags);
322 total_str = g_strdup_printf ("\naudio stream %d:\n", i);
323 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
325 if (gst_tag_list_get_string (tags, GST_TAG_AUDIO_CODEC, &str)) {
326 total_str = g_strdup_printf (" codec: %s\n", str);
327 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
331 if (gst_tag_list_get_string (tags, GST_TAG_LANGUAGE_CODE, &str)) {
332 total_str = g_strdup_printf (" language: %s\n", str);
333 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
337 if (gst_tag_list_get_uint (tags, GST_TAG_BITRATE, &rate)) {
338 total_str = g_strdup_printf (" bitrate: %d\n", rate);
339 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
342 gst_tag_list_free (tags);
346 for (i = 0; i < n_text; i++) {
348 /* Retrieve the stream's subtitle tags */
349 g_signal_emit_by_name (data->playbin, "get-text-tags", i, &tags);
351 total_str = g_strdup_printf ("\nsubtitle stream %d:\n", i);
352 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
354 if (gst_tag_list_get_string (tags, GST_TAG_LANGUAGE_CODE, &str)) {
355 total_str = g_strdup_printf (" language: %s\n", str);
356 gtk_text_buffer_insert_at_cursor (text, total_str, -1);
360 gst_tag_list_free (tags);
365 /* This function is called when an "application" message is posted on the bus.
366 * Here we retrieve the message posted by the tags_cb callback */
368 application_cb (GstBus * bus, GstMessage * msg, CustomData * data)
370 if (g_strcmp0 (gst_structure_get_name (gst_message_get_structure (msg)),
371 "tags-changed") == 0) {
372 /* If the message is the "tags-changed" (only one we are currently issuing), update
373 * the stream info GUI */
374 analyze_streams (data);
379 tutorial_main (int argc, char *argv[])
382 GstStateChangeReturn ret;
386 gtk_init (&argc, &argv);
388 /* Initialize GStreamer */
389 gst_init (&argc, &argv);
391 /* Initialize our data structure */
392 memset (&data, 0, sizeof (data));
393 data.duration = GST_CLOCK_TIME_NONE;
395 /* Create the elements */
396 data.playbin = gst_element_factory_make ("playbin", "playbin");
399 g_printerr ("Not all elements could be created.\n");
403 /* Set the URI to play */
404 g_object_set (data.playbin, "uri",
405 "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm",
408 /* Connect to interesting signals in playbin */
409 g_signal_connect (G_OBJECT (data.playbin), "video-tags-changed",
410 (GCallback) tags_cb, &data);
411 g_signal_connect (G_OBJECT (data.playbin), "audio-tags-changed",
412 (GCallback) tags_cb, &data);
413 g_signal_connect (G_OBJECT (data.playbin), "text-tags-changed",
414 (GCallback) tags_cb, &data);
419 /* Instruct the bus to emit signals for each received message, and connect to the interesting signals */
420 bus = gst_element_get_bus (data.playbin);
421 gst_bus_add_signal_watch (bus);
422 g_signal_connect (G_OBJECT (bus), "message::error", (GCallback) error_cb,
424 g_signal_connect (G_OBJECT (bus), "message::eos", (GCallback) eos_cb, &data);
425 g_signal_connect (G_OBJECT (bus), "message::state-changed",
426 (GCallback) state_changed_cb, &data);
427 g_signal_connect (G_OBJECT (bus), "message::application",
428 (GCallback) application_cb, &data);
429 gst_object_unref (bus);
432 ret = gst_element_set_state (data.playbin, GST_STATE_PLAYING);
433 if (ret == GST_STATE_CHANGE_FAILURE) {
434 g_printerr ("Unable to set the pipeline to the playing state.\n");
435 gst_object_unref (data.playbin);
439 /* Register a function that GLib will call every second */
440 g_timeout_add_seconds (1, (GSourceFunc) refresh_ui, &data);
442 /* Start the GTK main loop. We will not regain control until gtk_main_quit is called. */
446 gst_element_set_state (data.playbin, GST_STATE_NULL);
447 gst_object_unref (data.playbin);
452 main (int argc, char *argv[])
454 #if defined(__APPLE__) && TARGET_OS_MAC && !TARGET_OS_IPHONE
455 return gst_macos_main (tutorial_main, argc, argv, NULL);
457 return tutorial_main (argc, argv);