2 * (c) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
3 * (c) 2006 Jan Schmidt <thaytan@noraisin.net>
4 * (c) 2008 Stefan Kost <ensonic@users.sf.net>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
23 * SECTION:element-autovideosrc
24 * @see_also: autoaudiosrc, v4l2src, v4lsrc
26 * autovideosrc is a video src that automatically detects an appropriate
27 * video source to use. It does so by scanning the registry for all elements
28 * that have <quote>Source</quote> and <quote>Video</quote> in the class field
29 * of their element information, and also have a non-zero autoplugging rank.
32 * <title>Example launch line</title>
34 * gst-launch -v -m autovideosrc ! xvimagesink
45 #include "gstautovideosrc.h"
46 #include "gstautodetect.h"
55 static GstStateChangeReturn
56 gst_auto_video_src_change_state (GstElement * element,
57 GstStateChange transition);
58 static void gst_auto_video_src_dispose (GstAutoVideoSrc * src);
59 static void gst_auto_video_src_clear_kid (GstAutoVideoSrc * src);
61 static void gst_auto_video_src_set_property (GObject * object, guint prop_id,
62 const GValue * value, GParamSpec * pspec);
63 static void gst_auto_video_src_get_property (GObject * object, guint prop_id,
64 GValue * value, GParamSpec * pspec);
66 #define gst_auto_video_src_parent_class parent_class
67 G_DEFINE_TYPE (GstAutoVideoSrc, gst_auto_video_src, GST_TYPE_BIN);
69 static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
75 gst_auto_video_src_class_init (GstAutoVideoSrcClass * klass)
77 GObjectClass *gobject_class;
78 GstElementClass *eklass = GST_ELEMENT_CLASS (klass);
80 gobject_class = G_OBJECT_CLASS (klass);
81 gobject_class->dispose = (GObjectFinalizeFunc) gst_auto_video_src_dispose;
82 gobject_class->set_property = gst_auto_video_src_set_property;
83 gobject_class->get_property = gst_auto_video_src_get_property;
85 eklass->change_state = GST_DEBUG_FUNCPTR (gst_auto_video_src_change_state);
88 * GstAutoVideoSrc:filter-caps
90 * This property will filter out candidate sources that can handle the specified
91 * caps. By default only video sources that support raw rgb and yuv video
94 * This property can only be set before the element goes to the READY state.
98 g_object_class_install_property (gobject_class, PROP_CAPS,
99 g_param_spec_boxed ("filter-caps", "Filter caps",
100 "Filter src candidates using these caps.", GST_TYPE_CAPS,
101 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
103 gst_element_class_add_pad_template (eklass,
104 gst_static_pad_template_get (&src_template));
105 gst_element_class_set_details_simple (eklass, "Auto video source",
107 "Wrapper video source for automatically detected video source",
108 "Jan Schmidt <thaytan@noraisin.net>, "
109 "Stefan Kost <ensonic@users.sf.net>");
113 gst_auto_video_src_dispose (GstAutoVideoSrc * src)
115 gst_auto_video_src_clear_kid (src);
117 if (src->filter_caps)
118 gst_caps_unref (src->filter_caps);
119 src->filter_caps = NULL;
121 G_OBJECT_CLASS (parent_class)->dispose ((GObject *) src);
125 gst_auto_video_src_clear_kid (GstAutoVideoSrc * src)
128 gst_element_set_state (src->kid, GST_STATE_NULL);
129 gst_bin_remove (GST_BIN (src), src->kid);
131 /* Don't loose SOURCE flag */
132 GST_OBJECT_FLAG_SET (src, GST_ELEMENT_IS_SOURCE);
137 * Hack to make initial linking work; ideally, this'd work even when
138 * no target has been assigned to the ghostpad yet.
142 gst_auto_video_src_reset (GstAutoVideoSrc * src)
146 /* Remove any existing element */
147 gst_auto_video_src_clear_kid (src);
149 /* fakesrc placeholder */
150 src->kid = gst_element_factory_make ("fakesrc", "tempsrc");
151 gst_bin_add (GST_BIN (src), src->kid);
154 targetpad = gst_element_get_static_pad (src->kid, "src");
155 gst_ghost_pad_set_target (GST_GHOST_PAD (src->pad), targetpad);
156 gst_object_unref (targetpad);
159 static GstStaticCaps raw_caps =
160 GST_STATIC_CAPS ("video/x-raw-yuv; video/x-raw-rgb");
163 gst_auto_video_src_init (GstAutoVideoSrc * src)
165 src->pad = gst_ghost_pad_new_no_target ("src", GST_PAD_SRC);
166 gst_element_add_pad (GST_ELEMENT (src), src->pad);
168 gst_auto_video_src_reset (src);
170 /* set the default raw video caps */
171 src->filter_caps = gst_static_caps_get (&raw_caps);
174 GST_OBJECT_FLAG_SET (src, GST_ELEMENT_IS_SOURCE);
178 gst_auto_video_src_factory_filter (GstPluginFeature * feature, gpointer data)
183 /* we only care about element factories */
184 if (!GST_IS_ELEMENT_FACTORY (feature))
188 klass = gst_element_factory_get_klass (GST_ELEMENT_FACTORY (feature));
189 if (!(strstr (klass, "Source") && strstr (klass, "Video")))
192 /* only select elements with autoplugging rank */
193 rank = gst_plugin_feature_get_rank (feature);
194 if (rank < GST_RANK_MARGINAL)
201 gst_auto_video_src_compare_ranks (GstPluginFeature * f1, GstPluginFeature * f2)
205 diff = gst_plugin_feature_get_rank (f2) - gst_plugin_feature_get_rank (f1);
208 return strcmp (gst_plugin_feature_get_name (f2),
209 gst_plugin_feature_get_name (f1));
213 gst_auto_video_src_create_element_with_pretty_name (GstAutoVideoSrc * src,
214 GstElementFactory * factory)
217 gchar *name, *marker;
219 marker = g_strdup (GST_OBJECT_NAME (factory));
220 if (g_str_has_suffix (marker, "src"))
221 marker[strlen (marker) - 4] = '\0';
222 if (g_str_has_prefix (marker, "gst"))
223 g_memmove (marker, marker + 3, strlen (marker + 3) + 1);
224 name = g_strdup_printf ("%s-actual-src-%s", GST_OBJECT_NAME (src), marker);
227 element = gst_element_factory_create (factory, name);
234 gst_auto_video_src_find_best (GstAutoVideoSrc * src)
237 GstElement *choice = NULL;
238 GstMessage *message = NULL;
239 GSList *errors = NULL;
240 GstBus *bus = gst_bus_new ();
241 GstPad *el_pad = NULL;
242 GstCaps *el_caps = NULL;
243 gboolean no_match = TRUE;
245 list = gst_registry_feature_filter (gst_registry_get_default (),
246 (GstPluginFeatureFilter) gst_auto_video_src_factory_filter, FALSE, src);
247 list = g_list_sort (list, (GCompareFunc) gst_auto_video_src_compare_ranks);
249 GST_LOG_OBJECT (src, "Trying to find usable video devices ...");
251 for (item = list; item != NULL; item = item->next) {
252 GstElementFactory *f = GST_ELEMENT_FACTORY (item->data);
255 if ((el = gst_auto_video_src_create_element_with_pretty_name (src, f))) {
256 GstStateChangeReturn ret;
258 GST_DEBUG_OBJECT (src, "Testing %s", GST_OBJECT_NAME (f));
260 /* If AutoVideoSrc has been provided with filter caps,
261 * accept only sources that match with the filter caps */
262 if (src->filter_caps) {
263 el_pad = gst_element_get_static_pad (GST_ELEMENT (el), "src");
264 el_caps = gst_pad_get_caps (el_pad, NULL);
265 gst_object_unref (el_pad);
266 GST_DEBUG_OBJECT (src,
267 "Checking caps: %" GST_PTR_FORMAT " vs. %" GST_PTR_FORMAT,
268 src->filter_caps, el_caps);
269 no_match = !gst_caps_can_intersect (src->filter_caps, el_caps);
270 gst_caps_unref (el_caps);
273 GST_DEBUG_OBJECT (src, "Incompatible caps");
274 gst_object_unref (el);
277 GST_DEBUG_OBJECT (src, "Found compatible caps");
281 gst_element_set_bus (el, bus);
282 ret = gst_element_set_state (el, GST_STATE_READY);
283 if (ret == GST_STATE_CHANGE_SUCCESS) {
284 GST_DEBUG_OBJECT (src, "This worked!");
289 /* collect all error messages */
290 while ((message = gst_bus_pop_filtered (bus, GST_MESSAGE_ERROR))) {
291 GST_DEBUG_OBJECT (src, "error message %" GST_PTR_FORMAT, message);
292 errors = g_slist_append (errors, message);
295 gst_element_set_state (el, GST_STATE_NULL);
296 gst_object_unref (el);
300 GST_DEBUG_OBJECT (src, "done trying");
303 /* FIXME: we forward the first error for now; but later on it might make
304 * sense to actually analyse them */
305 gst_message_ref (GST_MESSAGE (errors->data));
306 GST_DEBUG_OBJECT (src, "reposting message %p", errors->data);
307 gst_element_post_message (GST_ELEMENT (src), GST_MESSAGE (errors->data));
309 /* send warning message to application and use a fakesrc */
310 GST_ELEMENT_WARNING (src, RESOURCE, NOT_FOUND, (NULL),
311 ("Failed to find a usable video source"));
312 choice = gst_element_factory_make ("fakesrc", "fake-video-src");
313 if (g_object_class_find_property (G_OBJECT_GET_CLASS (choice), "sync"))
314 g_object_set (choice, "sync", TRUE, NULL);
315 gst_element_set_state (choice, GST_STATE_READY);
318 gst_object_unref (bus);
319 gst_plugin_feature_list_free (list);
320 g_slist_foreach (errors, (GFunc) gst_mini_object_unref, NULL);
321 g_slist_free (errors);
327 gst_auto_video_src_detect (GstAutoVideoSrc * src)
332 gst_auto_video_src_clear_kid (src);
335 GST_DEBUG_OBJECT (src, "Creating new kid");
336 if (!(esrc = gst_auto_video_src_find_best (src)))
340 gst_bin_add (GST_BIN (src), esrc);
342 /* attach ghost pad */
343 GST_DEBUG_OBJECT (src, "Re-assigning ghostpad");
344 targetpad = gst_element_get_static_pad (src->kid, "src");
345 if (!gst_ghost_pad_set_target (GST_GHOST_PAD (src->pad), targetpad))
348 gst_object_unref (targetpad);
349 GST_DEBUG_OBJECT (src, "done changing auto video source");
356 GST_ELEMENT_ERROR (src, LIBRARY, INIT, (NULL),
357 ("Failed to find a supported video source"));
362 GST_ELEMENT_ERROR (src, LIBRARY, INIT, (NULL),
363 ("Failed to set target pad"));
364 gst_object_unref (targetpad);
369 static GstStateChangeReturn
370 gst_auto_video_src_change_state (GstElement * element,
371 GstStateChange transition)
373 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
374 GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (element);
376 switch (transition) {
377 case GST_STATE_CHANGE_NULL_TO_READY:
378 if (!gst_auto_video_src_detect (src))
379 return GST_STATE_CHANGE_FAILURE;
385 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
387 switch (transition) {
388 case GST_STATE_CHANGE_READY_TO_NULL:
389 gst_auto_video_src_reset (src);
399 gst_auto_video_src_set_property (GObject * object, guint prop_id,
400 const GValue * value, GParamSpec * pspec)
402 GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (object);
406 if (src->filter_caps)
407 gst_caps_unref (src->filter_caps);
408 src->filter_caps = gst_caps_copy (gst_value_get_caps (value));
411 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
417 gst_auto_video_src_get_property (GObject * object, guint prop_id,
418 GValue * value, GParamSpec * pspec)
420 GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (object);
424 gst_value_set_caps (value, src->filter_caps);
428 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);