2 * Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
3 * 2009 Nokia Corporation
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
22 * SECTION:gstdiscoverer
23 * @short_description: Utility for discovering information on URIs.
25 * The #GstDiscoverer is a utility object which allows to get as much
26 * information as possible from one or many URIs.
28 * It provides two APIs, allowing usage in blocking or non-blocking mode.
30 * The blocking mode just requires calling gst_discoverer_discover_uri()
31 * with the URI one wishes to discover.
33 * The non-blocking mode requires a running #GMainLoop in the default
34 * #GMainContext, where one connects to the various signals, appends the
35 * URIs to be processed (through gst_discoverer_discover_uri_async()) and then
36 * asks for the discovery to begin (through gst_discoverer_start()).
38 * All the information is returned in a #GstDiscovererInfo structure.
48 #include "pbutils-marshal.h"
49 #include "pbutils-private.h"
51 #include "gst/glib-compat-private.h"
53 GST_DEBUG_CATEGORY_STATIC (discoverer_debug);
54 #define GST_CAT_DEFAULT discoverer_debug
56 static GQuark _CAPS_QUARK;
57 static GQuark _TAGS_QUARK;
58 static GQuark _MISSING_PLUGIN_QUARK;
59 static GQuark _STREAM_TOPOLOGY_QUARK;
60 static GQuark _TOPOLOGY_PAD_QUARK;
72 struct _GstDiscovererPrivate
76 /* allowed time to discover each uri in nanoseconds */
79 /* list of pending URI to process (current excluded) */
84 /* TRUE if processing a URI */
87 /* TRUE if discoverer has been started */
91 GstDiscovererInfo *current_info;
92 GError *current_error;
93 GstStructure *current_topology;
95 /* List of private streams */
100 GstElement *uridecodebin;
103 GType decodebin2_type;
105 /* Custom main context variables */
110 /* reusable queries */
111 GstQuery *seeking_query;
113 /* Handler ids for various callbacks */
115 gulong pad_remove_id;
116 gulong element_added_id;
120 #define DISCO_LOCK(dc) g_mutex_lock (dc->priv->lock);
121 #define DISCO_UNLOCK(dc) g_mutex_unlock (dc->priv->lock);
126 GST_DEBUG_CATEGORY_INIT (discoverer_debug, "discoverer", 0, "Discoverer");
128 _CAPS_QUARK = g_quark_from_static_string ("caps");
129 _TAGS_QUARK = g_quark_from_static_string ("tags");
130 _MISSING_PLUGIN_QUARK = g_quark_from_static_string ("missing-plugin");
131 _STREAM_TOPOLOGY_QUARK = g_quark_from_static_string ("stream-topology");
132 _TOPOLOGY_PAD_QUARK = g_quark_from_static_string ("pad");
135 G_DEFINE_TYPE_EXTENDED (GstDiscoverer, gst_discoverer, G_TYPE_OBJECT, 0,
146 #define DEFAULT_PROP_TIMEOUT 15 * GST_SECOND
154 static guint gst_discoverer_signals[LAST_SIGNAL] = { 0 };
156 static void gst_discoverer_set_timeout (GstDiscoverer * dc,
157 GstClockTime timeout);
158 static gboolean async_timeout_cb (GstDiscoverer * dc);
160 static void discoverer_bus_cb (GstBus * bus, GstMessage * msg,
162 static void uridecodebin_pad_added_cb (GstElement * uridecodebin, GstPad * pad,
164 static void uridecodebin_pad_removed_cb (GstElement * uridecodebin,
165 GstPad * pad, GstDiscoverer * dc);
167 static void gst_discoverer_dispose (GObject * dc);
168 static void gst_discoverer_set_property (GObject * object, guint prop_id,
169 const GValue * value, GParamSpec * pspec);
170 static void gst_discoverer_get_property (GObject * object, guint prop_id,
171 GValue * value, GParamSpec * pspec);
174 gst_discoverer_class_init (GstDiscovererClass * klass)
176 GObjectClass *gobject_class = (GObjectClass *) klass;
178 gobject_class->dispose = gst_discoverer_dispose;
180 gobject_class->set_property = gst_discoverer_set_property;
181 gobject_class->get_property = gst_discoverer_get_property;
183 g_type_class_add_private (klass, sizeof (GstDiscovererPrivate));
187 * GstDiscoverer:timeout
189 * The duration (in nanoseconds) after which the discovery of an individual
192 * If the discovery of a URI times out, the %GST_DISCOVERER_TIMEOUT will be
193 * set on the result flags.
195 g_object_class_install_property (gobject_class, PROP_TIMEOUT,
196 g_param_spec_uint64 ("timeout", "timeout", "Timeout",
197 GST_SECOND, 3600 * GST_SECOND, DEFAULT_PROP_TIMEOUT,
198 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
202 * GstDiscoverer::finished:
203 * @discoverer: the #GstDiscoverer
205 * Will be emitted when all pending URIs have been processed.
207 gst_discoverer_signals[SIGNAL_FINISHED] =
208 g_signal_new ("finished", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
209 G_STRUCT_OFFSET (GstDiscovererClass, finished),
210 NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
213 * GstDiscoverer::starting:
214 * @discoverer: the #GstDiscoverer
216 * Will be emitted when the discover starts analyzing the pending URIs
218 gst_discoverer_signals[SIGNAL_STARTING] =
219 g_signal_new ("starting", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
220 G_STRUCT_OFFSET (GstDiscovererClass, starting),
221 NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
224 * GstDiscoverer::discovered:
225 * @discoverer: the #GstDiscoverer
226 * @info: the results #GstDiscovererInfo
227 * @error: (type GLib.Error): #GError, which will be non-NULL if an error
228 * occurred during discovery
230 * Will be emitted when all information on a URI could be discovered.
232 gst_discoverer_signals[SIGNAL_DISCOVERED] =
233 g_signal_new ("discovered", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
234 G_STRUCT_OFFSET (GstDiscovererClass, discovered),
235 NULL, NULL, pbutils_marshal_VOID__POINTER_BOXED,
236 G_TYPE_NONE, 2, GST_TYPE_DISCOVERER_INFO, GST_TYPE_G_ERROR);
240 uridecodebin_element_added_cb (GstElement * uridecodebin,
241 GstElement * child, GstDiscoverer * dc)
243 GST_DEBUG ("New element added to uridecodebin : %s",
244 GST_ELEMENT_NAME (child));
246 if (G_OBJECT_TYPE (child) == dc->priv->decodebin2_type) {
247 g_object_set (child, "post-stream-topology", TRUE, NULL);
252 gst_discoverer_init (GstDiscoverer * dc)
255 GstFormat format = GST_FORMAT_TIME;
257 dc->priv = G_TYPE_INSTANCE_GET_PRIVATE (dc, GST_TYPE_DISCOVERER,
258 GstDiscovererPrivate);
260 dc->priv->timeout = DEFAULT_PROP_TIMEOUT;
261 dc->priv->async = FALSE;
263 dc->priv->lock = g_mutex_new ();
265 GST_LOG ("Creating pipeline");
266 dc->priv->pipeline = (GstBin *) gst_pipeline_new ("Discoverer");
267 GST_LOG_OBJECT (dc, "Creating uridecodebin");
268 dc->priv->uridecodebin =
269 gst_element_factory_make ("uridecodebin", "discoverer-uri");
270 if (G_UNLIKELY (dc->priv->uridecodebin == NULL)) {
271 GST_ERROR ("Can't create uridecodebin");
274 GST_LOG_OBJECT (dc, "Adding uridecodebin to pipeline");
275 gst_bin_add (dc->priv->pipeline, dc->priv->uridecodebin);
277 dc->priv->pad_added_id =
278 g_signal_connect_object (dc->priv->uridecodebin, "pad-added",
279 G_CALLBACK (uridecodebin_pad_added_cb), dc, 0);
280 dc->priv->pad_remove_id =
281 g_signal_connect_object (dc->priv->uridecodebin, "pad-removed",
282 G_CALLBACK (uridecodebin_pad_removed_cb), dc, 0);
284 GST_LOG_OBJECT (dc, "Getting pipeline bus");
285 dc->priv->bus = gst_pipeline_get_bus ((GstPipeline *) dc->priv->pipeline);
287 dc->priv->bus_cb_id =
288 g_signal_connect_object (dc->priv->bus, "message",
289 G_CALLBACK (discoverer_bus_cb), dc, 0);
291 GST_DEBUG_OBJECT (dc, "Done initializing Discoverer");
293 /* This is ugly. We get the GType of decodebin2 so we can quickly detect
294 * when a decodebin2 is added to uridecodebin so we can set the
295 * post-stream-topology setting to TRUE */
296 dc->priv->element_added_id =
297 g_signal_connect_object (dc->priv->uridecodebin, "element-added",
298 G_CALLBACK (uridecodebin_element_added_cb), dc, 0);
299 tmp = gst_element_factory_make ("decodebin2", NULL);
300 dc->priv->decodebin2_type = G_OBJECT_TYPE (tmp);
301 gst_object_unref (tmp);
304 dc->priv->seeking_query = gst_query_new_seeking (format);
308 discoverer_reset (GstDiscoverer * dc)
310 GST_DEBUG_OBJECT (dc, "Resetting");
312 if (dc->priv->pending_uris) {
313 g_list_foreach (dc->priv->pending_uris, (GFunc) g_free, NULL);
314 g_list_free (dc->priv->pending_uris);
315 dc->priv->pending_uris = NULL;
318 if (dc->priv->pipeline)
319 gst_element_set_state ((GstElement *) dc->priv->pipeline, GST_STATE_NULL);
322 #define DISCONNECT_SIGNAL(o,i) G_STMT_START{ \
323 if ((i) && g_signal_handler_is_connected ((o), (i))) \
324 g_signal_handler_disconnect ((o), (i)); \
329 gst_discoverer_dispose (GObject * obj)
331 GstDiscoverer *dc = (GstDiscoverer *) obj;
333 GST_DEBUG_OBJECT (dc, "Disposing");
335 discoverer_reset (dc);
337 if (G_LIKELY (dc->priv->pipeline)) {
338 /* Workaround for bug #118536 */
339 DISCONNECT_SIGNAL (dc->priv->uridecodebin, dc->priv->pad_added_id);
340 DISCONNECT_SIGNAL (dc->priv->uridecodebin, dc->priv->pad_remove_id);
341 DISCONNECT_SIGNAL (dc->priv->uridecodebin, dc->priv->element_added_id);
342 DISCONNECT_SIGNAL (dc->priv->bus, dc->priv->bus_cb_id);
344 /* pipeline was set to NULL in _reset */
345 gst_object_unref (dc->priv->pipeline);
346 gst_object_unref (dc->priv->bus);
348 dc->priv->pipeline = NULL;
349 dc->priv->uridecodebin = NULL;
350 dc->priv->bus = NULL;
353 gst_discoverer_stop (dc);
355 if (dc->priv->lock) {
356 g_mutex_free (dc->priv->lock);
357 dc->priv->lock = NULL;
360 if (dc->priv->seeking_query) {
361 gst_query_unref (dc->priv->seeking_query);
362 dc->priv->seeking_query = NULL;
365 G_OBJECT_CLASS (gst_discoverer_parent_class)->dispose (obj);
369 gst_discoverer_set_property (GObject * object, guint prop_id,
370 const GValue * value, GParamSpec * pspec)
372 GstDiscoverer *dc = (GstDiscoverer *) object;
376 gst_discoverer_set_timeout (dc, g_value_get_uint64 (value));
379 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
385 gst_discoverer_get_property (GObject * object, guint prop_id,
386 GValue * value, GParamSpec * pspec)
388 GstDiscoverer *dc = (GstDiscoverer *) object;
393 g_value_set_uint64 (value, dc->priv->timeout);
397 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
403 gst_discoverer_set_timeout (GstDiscoverer * dc, GstClockTime timeout)
405 GST_DEBUG_OBJECT (dc, "timeout : %" GST_TIME_FORMAT, GST_TIME_ARGS (timeout));
407 /* FIXME : update current pending timeout if we're running */
409 dc->priv->timeout = timeout;
414 _event_probe (GstPad * pad, GstEvent * event, PrivateStream * ps)
416 if (GST_EVENT_TYPE (event) == GST_EVENT_TAG) {
417 GstTagList *tl = NULL, *tmp;
419 gst_event_parse_tag (event, &tl);
420 GST_DEBUG_OBJECT (pad, "tags %" GST_PTR_FORMAT, tl);
422 /* If preroll is complete, drop these tags - the collected information is
423 * possibly already being processed and adding more tags would be racy */
424 if (G_LIKELY (ps->dc->priv->processing)) {
425 GST_DEBUG_OBJECT (pad, "private stream %p old tags %" GST_PTR_FORMAT, ps,
427 tmp = gst_tag_list_merge (ps->tags, tl, GST_TAG_MERGE_APPEND);
429 gst_tag_list_free (ps->tags);
431 GST_DEBUG_OBJECT (pad, "private stream %p new tags %" GST_PTR_FORMAT, ps,
434 GST_DEBUG_OBJECT (pad, "Dropping tags since preroll is done");
435 DISCO_UNLOCK (ps->dc);
441 static GstStaticCaps subtitle_caps = GST_STATIC_CAPS ("text/plain; "
442 "text/x-pango-markup; subpicture/x-pgs; subpicture/x-dvb; "
443 "application/x-subtitle-unknown; application/x-ssa; application/x-ass; "
444 "subtitle/x-kate; application/x-kate; video/x-dvd-subpicture");
447 is_subtitle_caps (const GstCaps * caps)
452 subs_caps = gst_static_caps_get (&subtitle_caps);
453 ret = gst_caps_can_intersect (caps, subs_caps);
454 gst_caps_unref (subs_caps);
460 uridecodebin_pad_added_cb (GstElement * uridecodebin, GstPad * pad,
464 GstPad *sinkpad = NULL;
467 GST_DEBUG_OBJECT (dc, "pad %s:%s", GST_DEBUG_PAD_NAME (pad));
469 ps = g_slice_new0 (PrivateStream);
473 ps->queue = gst_element_factory_make ("queue", NULL);
474 ps->sink = gst_element_factory_make ("fakesink", NULL);
476 if (G_UNLIKELY (ps->queue == NULL || ps->sink == NULL))
479 g_object_set (ps->sink, "silent", TRUE, NULL);
480 g_object_set (ps->queue, "max-size-buffers", 1, "silent", TRUE, NULL);
482 caps = gst_pad_get_caps_reffed (pad);
484 if (is_subtitle_caps (caps)) {
485 /* Subtitle streams are sparse and may not provide any information - don't
486 * wait for data to preroll */
487 g_object_set (ps->sink, "async", FALSE, NULL);
490 gst_caps_unref (caps);
492 gst_bin_add_many (dc->priv->pipeline, ps->queue, ps->sink, NULL);
494 if (!gst_element_link_pads_full (ps->queue, "src", ps->sink, "sink",
495 GST_PAD_LINK_CHECK_NOTHING))
497 if (!gst_element_sync_state_with_parent (ps->sink))
499 if (!gst_element_sync_state_with_parent (ps->queue))
502 sinkpad = gst_element_get_static_pad (ps->queue, "sink");
505 if (gst_pad_link_full (pad, sinkpad,
506 GST_PAD_LINK_CHECK_NOTHING) != GST_PAD_LINK_OK)
508 gst_object_unref (sinkpad);
510 /* Add an event probe */
511 gst_pad_add_event_probe (pad, G_CALLBACK (_event_probe), ps);
514 dc->priv->streams = g_list_append (dc->priv->streams, ps);
517 GST_DEBUG_OBJECT (dc, "Done handling pad");
522 GST_ERROR_OBJECT (dc, "Error while handling pad");
524 gst_object_unref (sinkpad);
526 gst_object_unref (ps->queue);
528 gst_object_unref (ps->sink);
529 g_slice_free (PrivateStream, ps);
534 uridecodebin_pad_removed_cb (GstElement * uridecodebin, GstPad * pad,
541 GST_DEBUG_OBJECT (dc, "pad %s:%s", GST_DEBUG_PAD_NAME (pad));
543 /* Find the PrivateStream */
545 for (tmp = dc->priv->streams; tmp; tmp = tmp->next) {
546 ps = (PrivateStream *) tmp->data;
553 GST_DEBUG ("The removed pad wasn't controlled by us !");
557 dc->priv->streams = g_list_delete_link (dc->priv->streams, tmp);
560 gst_element_set_state (ps->sink, GST_STATE_NULL);
561 gst_element_set_state (ps->queue, GST_STATE_NULL);
562 gst_element_unlink (ps->queue, ps->sink);
564 sinkpad = gst_element_get_static_pad (ps->queue, "sink");
565 gst_pad_unlink (pad, sinkpad);
566 gst_object_unref (sinkpad);
568 /* references removed here */
569 gst_bin_remove_many (dc->priv->pipeline, ps->sink, ps->queue, NULL);
572 gst_tag_list_free (ps->tags);
575 g_slice_free (PrivateStream, ps);
577 GST_DEBUG ("Done handling pad");
580 static GstStructure *
581 collect_stream_information (GstDiscoverer * dc, PrivateStream * ps, guint idx)
587 stname = g_strdup_printf ("stream-%02d", idx);
588 st = gst_structure_empty_new (stname);
592 caps = gst_pad_get_negotiated_caps (ps->pad);
594 GST_WARNING ("Couldn't get negotiated caps from %s:%s",
595 GST_DEBUG_PAD_NAME (ps->pad));
596 caps = gst_pad_get_caps (ps->pad);
599 GST_DEBUG ("Got caps %" GST_PTR_FORMAT, caps);
600 gst_structure_id_set (st, _CAPS_QUARK, GST_TYPE_CAPS, caps, NULL);
602 gst_caps_unref (caps);
605 gst_structure_id_set (st, _TAGS_QUARK, GST_TYPE_TAG_LIST, ps->tags, NULL);
610 /* takes ownership of new_tags, may replace *taglist with a new one */
612 gst_discoverer_merge_and_replace_tags (GstTagList ** taglist,
613 GstTagList * new_tags)
615 if (new_tags == NULL)
618 if (*taglist == NULL) {
623 gst_tag_list_insert (*taglist, new_tags, GST_TAG_MERGE_REPLACE);
624 gst_tag_list_free (new_tags);
627 /* Parses a set of caps and tags in st and populates a GstDiscovererStreamInfo
628 * structure (parent, if !NULL, otherwise it allocates one)
630 static GstDiscovererStreamInfo *
631 collect_information (GstDiscoverer * dc, const GstStructure * st,
632 GstDiscovererStreamInfo * parent)
635 GstStructure *caps_st;
641 if (!st || !gst_structure_id_has_field (st, _CAPS_QUARK)) {
642 GST_WARNING ("Couldn't find caps !");
644 return gst_discoverer_stream_info_ref (parent);
646 return (GstDiscovererStreamInfo *)
647 gst_mini_object_new (GST_TYPE_DISCOVERER_STREAM_INFO);
650 gst_structure_id_get (st, _CAPS_QUARK, GST_TYPE_CAPS, &caps, NULL);
651 caps_st = gst_caps_get_structure (caps, 0);
652 name = gst_structure_get_name (caps_st);
654 if (g_str_has_prefix (name, "audio/")) {
655 GstDiscovererAudioInfo *info;
658 info = (GstDiscovererAudioInfo *) gst_discoverer_stream_info_ref (parent);
660 info = (GstDiscovererAudioInfo *)
661 gst_mini_object_new (GST_TYPE_DISCOVERER_AUDIO_INFO);
662 info->parent.caps = gst_caps_ref (caps);
665 if (gst_structure_get_int (caps_st, "rate", &tmp))
666 info->sample_rate = (guint) tmp;
668 if (gst_structure_get_int (caps_st, "channels", &tmp))
669 info->channels = (guint) tmp;
671 if (gst_structure_get_int (caps_st, "depth", &tmp))
672 info->depth = (guint) tmp;
674 if (gst_structure_id_has_field (st, _TAGS_QUARK)) {
675 gst_structure_id_get (st, _TAGS_QUARK, GST_TYPE_TAG_LIST, &tags_st, NULL);
676 if (gst_structure_get_uint (tags_st, GST_TAG_BITRATE, &utmp) ||
677 gst_structure_get_uint (tags_st, GST_TAG_NOMINAL_BITRATE, &utmp))
678 info->bitrate = utmp;
680 if (gst_structure_get_uint (tags_st, GST_TAG_MAXIMUM_BITRATE, &utmp))
681 info->max_bitrate = utmp;
683 /* FIXME: Is it worth it to remove the tags we've parsed? */
684 gst_discoverer_merge_and_replace_tags (&info->parent.tags, tags_st);
687 if (!info->language && ((GstDiscovererStreamInfo *) info)->tags) {
689 if (gst_tag_list_get_string (((GstDiscovererStreamInfo *) info)->tags,
690 GST_TAG_LANGUAGE_CODE, &language)) {
691 info->language = language;
695 gst_caps_unref (caps);
696 return (GstDiscovererStreamInfo *) info;
698 } else if (g_str_has_prefix (name, "video/") ||
699 g_str_has_prefix (name, "image/")) {
700 GstDiscovererVideoInfo *info;
703 info = (GstDiscovererVideoInfo *) gst_discoverer_stream_info_ref (parent);
705 info = (GstDiscovererVideoInfo *)
706 gst_mini_object_new (GST_TYPE_DISCOVERER_VIDEO_INFO);
707 info->parent.caps = gst_caps_ref (caps);
710 if (gst_structure_get_int (caps_st, "width", &tmp) &&
711 gst_structure_get_int (caps_st, "height", &tmp2)) {
712 info->width = (guint) tmp;
713 info->height = (guint) tmp2;
716 if (gst_structure_get_int (caps_st, "depth", &tmp))
717 info->depth = (guint) tmp;
719 if (gst_structure_get_fraction (caps_st, "pixel-aspect-ratio", &tmp, &tmp2)) {
721 info->par_denom = tmp2;
727 if (gst_structure_get_fraction (caps_st, "framerate", &tmp, &tmp2)) {
728 info->framerate_num = tmp;
729 info->framerate_denom = tmp2;
732 if (!gst_structure_get_boolean (caps_st, "interlaced", &info->interlaced))
733 info->interlaced = FALSE;
735 if (gst_structure_id_has_field (st, _TAGS_QUARK)) {
736 gst_structure_id_get (st, _TAGS_QUARK, GST_TYPE_TAG_LIST, &tags_st, NULL);
737 if (gst_structure_get_uint (tags_st, GST_TAG_BITRATE, &utmp) ||
738 gst_structure_get_uint (tags_st, GST_TAG_NOMINAL_BITRATE, &utmp))
739 info->bitrate = utmp;
741 if (gst_structure_get_uint (tags_st, GST_TAG_MAXIMUM_BITRATE, &utmp))
742 info->max_bitrate = utmp;
744 /* FIXME: Is it worth it to remove the tags we've parsed? */
745 gst_discoverer_merge_and_replace_tags (&info->parent.tags,
746 (GstTagList *) tags_st);
749 gst_caps_unref (caps);
750 return (GstDiscovererStreamInfo *) info;
752 } else if (is_subtitle_caps (caps)) {
753 GstDiscovererSubtitleInfo *info;
757 (GstDiscovererSubtitleInfo *) gst_discoverer_stream_info_ref (parent);
759 info = (GstDiscovererSubtitleInfo *)
760 gst_mini_object_new (GST_TYPE_DISCOVERER_SUBTITLE_INFO);
761 info->parent.caps = gst_caps_ref (caps);
764 if (gst_structure_id_has_field (st, _TAGS_QUARK)) {
765 const gchar *language;
767 gst_structure_id_get (st, _TAGS_QUARK, GST_TYPE_TAG_LIST, &tags_st, NULL);
769 language = gst_structure_get_string (caps_st, GST_TAG_LANGUAGE_CODE);
771 info->language = g_strdup (language);
773 /* FIXME: Is it worth it to remove the tags we've parsed? */
774 gst_discoverer_merge_and_replace_tags (&info->parent.tags, tags_st);
777 if (!info->language && ((GstDiscovererStreamInfo *) info)->tags) {
779 if (gst_tag_list_get_string (((GstDiscovererStreamInfo *) info)->tags,
780 GST_TAG_LANGUAGE_CODE, &language)) {
781 info->language = language;
785 gst_caps_unref (caps);
786 return (GstDiscovererStreamInfo *) info;
789 /* None of the above - populate what information we can */
790 GstDiscovererStreamInfo *info;
793 info = gst_discoverer_stream_info_ref (parent);
795 info = (GstDiscovererStreamInfo *)
796 gst_mini_object_new (GST_TYPE_DISCOVERER_STREAM_INFO);
797 info->caps = gst_caps_ref (caps);
800 if (gst_structure_id_get (st, _TAGS_QUARK,
801 GST_TYPE_TAG_LIST, &tags_st, NULL)) {
802 gst_discoverer_merge_and_replace_tags (&info->tags, tags_st);
805 gst_caps_unref (caps);
811 static GstStructure *
812 find_stream_for_node (GstDiscoverer * dc, const GstStructure * topology)
815 GstPad *target_pad = NULL;
816 GstStructure *st = NULL;
821 if (!gst_structure_id_has_field (topology, _TOPOLOGY_PAD_QUARK)) {
822 GST_DEBUG ("Could not find pad for node %" GST_PTR_FORMAT "\n", topology);
826 gst_structure_id_get (topology, _TOPOLOGY_PAD_QUARK,
827 GST_TYPE_PAD, &pad, NULL);
829 if (!dc->priv->streams) {
830 gst_object_unref (pad);
834 for (i = 0, tmp = dc->priv->streams; tmp; tmp = tmp->next, i++) {
835 ps = (PrivateStream *) tmp->data;
837 target_pad = gst_ghost_pad_get_target (GST_GHOST_PAD (ps->pad));
838 gst_object_unref (target_pad);
840 if (target_pad == pad)
845 st = collect_stream_information (dc, ps, i);
847 gst_object_unref (pad);
853 child_is_raw_stream (const GstCaps * parent, const GstCaps * child)
855 const GstStructure *st1, *st2;
856 const gchar *name1, *name2;
858 st1 = gst_caps_get_structure (parent, 0);
859 name1 = gst_structure_get_name (st1);
860 st2 = gst_caps_get_structure (child, 0);
861 name2 = gst_structure_get_name (st2);
863 if ((g_str_has_prefix (name1, "audio/") &&
864 g_str_has_prefix (name2, "audio/x-raw")) ||
865 ((g_str_has_prefix (name1, "video/") ||
866 g_str_has_prefix (name1, "image/")) &&
867 g_str_has_prefix (name2, "video/x-raw"))) {
868 /* child is the "raw" sub-stream corresponding to parent */
872 if (is_subtitle_caps (parent))
878 /* If a parent is non-NULL, collected stream information will be appended to it
879 * (and where the information exists, it will be overriden)
881 static GstDiscovererStreamInfo *
882 parse_stream_topology (GstDiscoverer * dc, const GstStructure * topology,
883 GstDiscovererStreamInfo * parent)
885 GstDiscovererStreamInfo *res = NULL;
886 GstCaps *caps = NULL;
887 const GValue *nval = NULL;
889 GST_DEBUG ("parsing: %" GST_PTR_FORMAT, topology);
891 nval = gst_structure_get_value (topology, "next");
893 if (nval == NULL || GST_VALUE_HOLDS_STRUCTURE (nval)) {
894 GstStructure *st = find_stream_for_node (dc, topology);
895 gboolean add_to_list = TRUE;
898 res = collect_information (dc, st, parent);
899 gst_structure_free (st);
901 /* Didn't find a stream structure, so let's just use the caps we have */
902 res = collect_information (dc, topology, parent);
906 /* FIXME : aggregate with information from main streams */
907 GST_DEBUG ("Coudn't find 'next' ! might be the last entry");
910 const GstStructure *st;
912 st = gst_value_get_structure (nval);
914 GST_DEBUG ("next is a structure %" GST_PTR_FORMAT, st);
919 if (gst_structure_id_get (st, _CAPS_QUARK, GST_TYPE_CAPS, &caps, NULL)) {
920 if (gst_caps_can_intersect (parent->caps, caps)) {
921 /* We sometimes get an extra sub-stream from the parser. If this is
922 * the case, we just replace the parent caps with this stream's caps
923 * since they might contain more information */
924 gst_caps_replace (&parent->caps, caps);
926 parse_stream_topology (dc, st, parent);
928 } else if (child_is_raw_stream (parent->caps, caps)) {
929 /* This is the "raw" stream corresponding to the parent. This
930 * contains more information than the parent, tags etc. */
931 parse_stream_topology (dc, st, parent);
934 GstDiscovererStreamInfo *next = parse_stream_topology (dc, st, NULL);
936 next->previous = res;
938 gst_caps_unref (caps);
943 dc->priv->current_info->stream_list =
944 g_list_append (dc->priv->current_info->stream_list, res);
946 gst_discoverer_stream_info_unref (res);
949 } else if (GST_VALUE_HOLDS_LIST (nval)) {
951 GstDiscovererContainerInfo *cont;
954 if (!gst_structure_id_get (topology, _CAPS_QUARK,
955 GST_TYPE_CAPS, &caps, NULL))
956 GST_WARNING ("Couldn't find caps !");
958 len = gst_value_list_get_size (nval);
959 GST_DEBUG ("next is a list of %d entries", len);
961 cont = (GstDiscovererContainerInfo *)
962 gst_mini_object_new (GST_TYPE_DISCOVERER_CONTAINER_INFO);
963 cont->parent.caps = caps;
964 res = (GstDiscovererStreamInfo *) cont;
966 if (gst_structure_id_has_field (topology, _TAGS_QUARK)) {
969 gst_structure_id_get (topology, _TAGS_QUARK,
970 GST_TYPE_TAG_LIST, &tags, NULL);
972 GST_DEBUG ("Merge tags %" GST_PTR_FORMAT, tags);
975 gst_tag_list_merge (cont->parent.tags, (GstTagList *) tags,
976 GST_TAG_MERGE_APPEND);
977 gst_tag_list_free (tags);
978 if (cont->parent.tags)
979 gst_tag_list_free (cont->parent.tags);
980 cont->parent.tags = tmp;
981 GST_DEBUG ("Container info tags %" GST_PTR_FORMAT, tmp);
984 for (i = 0; i < len; i++) {
985 const GValue *subv = gst_value_list_get_value (nval, i);
986 const GstStructure *subst = gst_value_get_structure (subv);
987 GstDiscovererStreamInfo *substream;
989 GST_DEBUG ("%d %" GST_PTR_FORMAT, i, subst);
991 substream = parse_stream_topology (dc, subst, NULL);
993 substream->previous = res;
995 g_list_append (cont->streams,
996 gst_discoverer_stream_info_ref (substream));
1003 /* Called when pipeline is pre-rolled */
1005 discoverer_collect (GstDiscoverer * dc)
1007 GST_DEBUG ("Collecting information");
1009 /* Stop the timeout handler if present */
1010 if (dc->priv->timeoutid) {
1011 g_source_remove (dc->priv->timeoutid);
1012 dc->priv->timeoutid = 0;
1015 if (dc->priv->streams) {
1016 /* FIXME : Make this querying optional */
1018 GstElement *pipeline = (GstElement *) dc->priv->pipeline;
1019 GstFormat format = GST_FORMAT_TIME;
1022 GST_DEBUG ("Attempting to query duration");
1024 if (gst_element_query_duration (pipeline, &format, &dur)) {
1025 if (format == GST_FORMAT_TIME) {
1026 GST_DEBUG ("Got duration %" GST_TIME_FORMAT, GST_TIME_ARGS (dur));
1027 dc->priv->current_info->duration = (guint64) dur;
1031 if (dc->priv->seeking_query) {
1032 if (gst_element_query (pipeline, dc->priv->seeking_query)) {
1035 gst_query_parse_seeking (dc->priv->seeking_query, &format,
1036 &seekable, NULL, NULL);
1037 if (format == GST_FORMAT_TIME) {
1038 GST_DEBUG ("Got seekable %d", seekable);
1039 dc->priv->current_info->seekable = seekable;
1045 if (dc->priv->current_topology)
1046 dc->priv->current_info->stream_info = parse_stream_topology (dc,
1047 dc->priv->current_topology, NULL);
1050 * Images need some special handling. They do not have a duration, have
1051 * caps named image/<foo> (th exception being MJPEG video which is also
1052 * type image/jpeg), and should consist of precisely one stream (actually
1053 * initially there are 2, the image and raw stream, but we squash these
1054 * while parsing the stream topology). At some point, if we find that these
1055 * conditions are not sufficient, we can count the number of decoders and
1056 * parsers in the chain, and if there's more than one decoder, or any
1057 * parser at all, we should not mark this as an image.
1059 if (dc->priv->current_info->duration == 0 &&
1060 dc->priv->current_info->stream_info != NULL &&
1061 dc->priv->current_info->stream_info->next == NULL) {
1063 gst_caps_get_structure (dc->priv->current_info->stream_info->caps, 0);
1065 if (g_str_has_prefix (gst_structure_get_name (st), "image/"))
1066 ((GstDiscovererVideoInfo *) dc->priv->current_info->stream_info)->
1071 if (dc->priv->async) {
1072 GST_DEBUG ("Emitting 'discoverered'");
1073 g_signal_emit (dc, gst_discoverer_signals[SIGNAL_DISCOVERED], 0,
1074 dc->priv->current_info, dc->priv->current_error);
1075 /* Clients get a copy of current_info since it is a boxed type */
1076 gst_discoverer_info_unref (dc->priv->current_info);
1081 get_async_cb (gpointer cb_data, GSource * source, GSourceFunc * func,
1084 *func = (GSourceFunc) async_timeout_cb;
1088 /* Wrapper since GSourceCallbackFuncs don't expect a return value from ref() */
1090 _void_g_object_ref (gpointer object)
1092 g_object_ref (G_OBJECT (object));
1096 handle_current_async (GstDiscoverer * dc)
1099 static GSourceCallbackFuncs cb_funcs = {
1105 /* Attach a timeout to the main context */
1106 source = g_timeout_source_new (dc->priv->timeout / GST_MSECOND);
1107 g_source_set_callback_indirect (source, g_object_ref (dc), &cb_funcs);
1108 dc->priv->timeoutid = g_source_attach (source, dc->priv->ctx);
1109 g_source_unref (source);
1113 /* Returns TRUE if processing should stop */
1115 handle_message (GstDiscoverer * dc, GstMessage * msg)
1117 gboolean done = FALSE;
1119 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (msg), "got a %s message",
1120 GST_MESSAGE_TYPE_NAME (msg));
1122 switch (GST_MESSAGE_TYPE (msg)) {
1123 case GST_MESSAGE_ERROR:{
1127 gst_message_parse_error (msg, &gerr, &debug);
1128 GST_WARNING_OBJECT (GST_MESSAGE_SRC (msg),
1129 "Got an error [debug:%s], [message:%s]", debug, gerr->message);
1130 dc->priv->current_error = gerr;
1133 /* We need to stop */
1136 GST_DEBUG ("Setting result to ERROR");
1137 dc->priv->current_info->result = GST_DISCOVERER_ERROR;
1141 case GST_MESSAGE_EOS:
1142 GST_DEBUG ("Got EOS !");
1146 case GST_MESSAGE_ASYNC_DONE:
1147 if (GST_MESSAGE_SRC (msg) == (GstObject *) dc->priv->pipeline) {
1148 GST_DEBUG ("Finished changing state asynchronously");
1154 case GST_MESSAGE_ELEMENT:
1156 GQuark sttype = gst_structure_get_name_id (msg->structure);
1157 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (msg),
1158 "structure %" GST_PTR_FORMAT, msg->structure);
1159 if (sttype == _MISSING_PLUGIN_QUARK) {
1160 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (msg),
1161 "Setting result to MISSING_PLUGINS");
1162 dc->priv->current_info->result = GST_DISCOVERER_MISSING_PLUGINS;
1163 if (dc->priv->current_info->misc)
1164 gst_structure_free (dc->priv->current_info->misc);
1165 dc->priv->current_info->misc = gst_structure_copy (msg->structure);
1166 } else if (sttype == _STREAM_TOPOLOGY_QUARK) {
1167 if (dc->priv->current_topology)
1168 gst_structure_free (dc->priv->current_topology);
1169 dc->priv->current_topology = gst_structure_copy (msg->structure);
1174 case GST_MESSAGE_TAG:
1176 GstTagList *tl, *tmp;
1178 gst_message_parse_tag (msg, &tl);
1179 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (msg), "Got tags %" GST_PTR_FORMAT, tl);
1180 /* Merge with current tags */
1182 gst_tag_list_merge (dc->priv->current_info->tags, tl,
1183 GST_TAG_MERGE_APPEND);
1184 gst_tag_list_free (tl);
1185 if (dc->priv->current_info->tags)
1186 gst_tag_list_free (dc->priv->current_info->tags);
1187 dc->priv->current_info->tags = tmp;
1188 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (msg), "Current info %p, tags %"
1189 GST_PTR_FORMAT, dc->priv->current_info, tmp);
1202 handle_current_sync (GstDiscoverer * dc)
1205 gdouble deadline = ((gdouble) dc->priv->timeout) / GST_SECOND;
1207 gboolean done = FALSE;
1209 timer = g_timer_new ();
1210 g_timer_start (timer);
1213 /* poll bus with timeout */
1214 /* FIXME : make the timeout more fine-tuned */
1215 if ((msg = gst_bus_timed_pop (dc->priv->bus, GST_SECOND / 2))) {
1216 done = handle_message (dc, msg);
1217 gst_message_unref (msg);
1219 } while (!done && (g_timer_elapsed (timer, NULL) < deadline));
1223 GST_DEBUG ("we timed out! Setting result to TIMEOUT");
1224 dc->priv->current_info->result = GST_DISCOVERER_TIMEOUT;
1229 g_timer_stop (timer);
1230 g_timer_destroy (timer);
1234 _setup_locked (GstDiscoverer * dc)
1236 GstStateChangeReturn ret;
1238 GST_DEBUG ("Setting up");
1240 /* Pop URI off the pending URI list */
1241 dc->priv->current_info =
1242 (GstDiscovererInfo *) gst_mini_object_new (GST_TYPE_DISCOVERER_INFO);
1243 dc->priv->current_info->uri = (gchar *) dc->priv->pending_uris->data;
1244 dc->priv->pending_uris =
1245 g_list_delete_link (dc->priv->pending_uris, dc->priv->pending_uris);
1247 /* set uri on uridecodebin */
1248 g_object_set (dc->priv->uridecodebin, "uri", dc->priv->current_info->uri,
1251 GST_DEBUG ("Current is now %s", dc->priv->current_info->uri);
1253 dc->priv->processing = TRUE;
1255 /* set pipeline to PAUSED */
1257 GST_DEBUG ("Setting pipeline to PAUSED");
1259 gst_element_set_state ((GstElement *) dc->priv->pipeline,
1263 GST_DEBUG_OBJECT (dc, "Pipeline going to PAUSED : %s",
1264 gst_element_state_change_return_get_name (ret));
1268 discoverer_cleanup (GstDiscoverer * dc)
1270 GST_DEBUG ("Cleaning up");
1272 gst_bus_set_flushing (dc->priv->bus, TRUE);
1273 gst_element_set_state ((GstElement *) dc->priv->pipeline, GST_STATE_READY);
1274 gst_bus_set_flushing (dc->priv->bus, FALSE);
1277 if (dc->priv->current_error)
1278 g_error_free (dc->priv->current_error);
1279 dc->priv->current_error = NULL;
1280 if (dc->priv->current_topology) {
1281 gst_structure_free (dc->priv->current_topology);
1282 dc->priv->current_topology = NULL;
1285 dc->priv->current_info = NULL;
1287 /* Try popping the next uri */
1288 if (dc->priv->async) {
1289 if (dc->priv->pending_uris != NULL) {
1293 handle_current_async (dc);
1297 g_signal_emit (dc, gst_discoverer_signals[SIGNAL_FINISHED], 0);
1306 discoverer_bus_cb (GstBus * bus, GstMessage * msg, GstDiscoverer * dc)
1308 if (dc->priv->processing) {
1309 if (handle_message (dc, msg)) {
1310 GST_DEBUG ("Stopping asynchronously");
1311 /* Serialise with _event_probe() */
1313 dc->priv->processing = FALSE;
1315 discoverer_collect (dc);
1316 discoverer_cleanup (dc);
1322 async_timeout_cb (GstDiscoverer * dc)
1324 if (!g_source_is_destroyed (g_main_current_source ())) {
1325 dc->priv->timeoutid = 0;
1326 GST_DEBUG ("Setting result to TIMEOUT");
1327 dc->priv->current_info->result = GST_DISCOVERER_TIMEOUT;
1328 dc->priv->processing = FALSE;
1329 discoverer_collect (dc);
1330 discoverer_cleanup (dc);
1335 /* If there is a pending URI, it will pop it from the list of pending
1336 * URIs and start the discovery on it.
1338 * Returns GST_DISCOVERER_OK if the next URI was popped and is processing,
1339 * else a error flag.
1341 static GstDiscovererResult
1342 start_discovering (GstDiscoverer * dc)
1344 GstDiscovererResult res = GST_DISCOVERER_OK;
1346 GST_DEBUG ("Starting");
1349 if (dc->priv->pending_uris == NULL) {
1350 GST_WARNING ("No URI to process");
1351 res = GST_DISCOVERER_URI_INVALID;
1356 if (dc->priv->current_info != NULL) {
1357 GST_WARNING ("Already processing a file");
1358 res = GST_DISCOVERER_BUSY;
1363 g_signal_emit (dc, gst_discoverer_signals[SIGNAL_STARTING], 0);
1369 if (dc->priv->async)
1370 handle_current_async (dc);
1372 handle_current_sync (dc);
1380 * gst_discoverer_start:
1381 * @discoverer: A #GstDiscoverer
1383 * Allow asynchronous discovering of URIs to take place.
1384 * A #GMainLoop must be available for #GstDiscoverer to properly work in
1385 * asynchronous mode.
1390 gst_discoverer_start (GstDiscoverer * discoverer)
1393 GMainContext *ctx = NULL;
1395 GST_DEBUG_OBJECT (discoverer, "Starting...");
1397 if (discoverer->priv->async) {
1398 GST_DEBUG_OBJECT (discoverer, "We were already started");
1402 discoverer->priv->async = TRUE;
1403 discoverer->priv->running = TRUE;
1405 ctx = g_main_context_get_thread_default ();
1407 /* Connect to bus signals */
1409 ctx = g_main_context_default ();
1411 source = gst_bus_create_watch (discoverer->priv->bus);
1412 g_source_set_callback (source, (GSourceFunc) gst_bus_async_signal_func,
1414 discoverer->priv->sourceid = g_source_attach (source, ctx);
1415 g_source_unref (source);
1416 discoverer->priv->ctx = g_main_context_ref (ctx);
1418 start_discovering (discoverer);
1419 GST_DEBUG_OBJECT (discoverer, "Started");
1423 * gst_discoverer_stop:
1424 * @discoverer: A #GstDiscoverer
1426 * Stop the discovery of any pending URIs and clears the list of
1427 * pending URIS (if any).
1432 gst_discoverer_stop (GstDiscoverer * discoverer)
1434 GST_DEBUG_OBJECT (discoverer, "Stopping...");
1436 if (!discoverer->priv->async) {
1437 GST_DEBUG_OBJECT (discoverer,
1438 "We were already stopped, or running synchronously");
1442 DISCO_LOCK (discoverer);
1443 if (discoverer->priv->processing) {
1444 /* We prevent any further processing by setting the bus to
1445 * flushing and setting the pipeline to READY.
1446 * _reset() will take care of the rest of the cleanup */
1447 if (discoverer->priv->bus)
1448 gst_bus_set_flushing (discoverer->priv->bus, TRUE);
1449 if (discoverer->priv->pipeline)
1450 gst_element_set_state ((GstElement *) discoverer->priv->pipeline,
1453 discoverer->priv->running = FALSE;
1454 DISCO_UNLOCK (discoverer);
1456 /* Remove timeout handler */
1457 if (discoverer->priv->timeoutid) {
1458 g_source_remove (discoverer->priv->timeoutid);
1459 discoverer->priv->timeoutid = 0;
1461 /* Remove signal watch */
1462 if (discoverer->priv->sourceid) {
1463 g_source_remove (discoverer->priv->sourceid);
1464 discoverer->priv->sourceid = 0;
1466 /* Unref main context */
1467 if (discoverer->priv->ctx) {
1468 g_main_context_unref (discoverer->priv->ctx);
1469 discoverer->priv->ctx = NULL;
1471 discoverer_reset (discoverer);
1473 discoverer->priv->async = FALSE;
1475 GST_DEBUG_OBJECT (discoverer, "Stopped");
1479 * gst_discoverer_discover_uri_async:
1480 * @discoverer: A #GstDiscoverer
1481 * @uri: the URI to add.
1483 * Appends the given @uri to the list of URIs to discoverer. The actual
1484 * discovery of the @uri will only take place if gst_discoverer_start() has
1487 * A copy of @uri will be made internally, so the caller can safely g_free()
1490 * Returns: %TRUE if the @uri was successfully appended to the list of pending
1496 gst_discoverer_discover_uri_async (GstDiscoverer * discoverer,
1501 GST_DEBUG_OBJECT (discoverer, "uri : %s", uri);
1503 DISCO_LOCK (discoverer);
1504 can_run = (discoverer->priv->pending_uris == NULL);
1505 discoverer->priv->pending_uris =
1506 g_list_append (discoverer->priv->pending_uris, g_strdup (uri));
1507 DISCO_UNLOCK (discoverer);
1510 start_discovering (discoverer);
1516 /* Synchronous mode */
1518 * gst_discoverer_discover_uri:
1519 * @discoverer: A #GstDiscoverer
1520 * @uri: The URI to run on.
1521 * @err: (out) (allow-none): If an error occurred, this field will be filled in.
1523 * Synchronously discovers the given @uri.
1525 * A copy of @uri will be made internally, so the caller can safely g_free()
1528 * Returns: (transfer full): the result of the scanning. Can be %NULL if an
1534 gst_discoverer_discover_uri (GstDiscoverer * discoverer, const gchar * uri,
1537 GstDiscovererResult res = 0;
1538 GstDiscovererInfo *info;
1540 GST_DEBUG_OBJECT (discoverer, "uri:%s", uri);
1542 DISCO_LOCK (discoverer);
1543 if (G_UNLIKELY (discoverer->priv->current_info)) {
1544 DISCO_UNLOCK (discoverer);
1545 GST_WARNING_OBJECT (discoverer, "Already handling a uri");
1549 discoverer->priv->pending_uris =
1550 g_list_append (discoverer->priv->pending_uris, g_strdup (uri));
1551 DISCO_UNLOCK (discoverer);
1553 res = start_discovering (discoverer);
1554 discoverer_collect (discoverer);
1558 if (discoverer->priv->current_error)
1559 *err = g_error_copy (discoverer->priv->current_error);
1563 if (res != GST_DISCOVERER_OK) {
1564 GST_DEBUG ("Setting result to %d (was %d)", res,
1565 discoverer->priv->current_info->result);
1566 discoverer->priv->current_info->result = res;
1568 info = discoverer->priv->current_info;
1570 discoverer_cleanup (discoverer);
1576 * gst_discoverer_new:
1577 * @timeout: timeout per file, in nanoseconds. Allowed are values between
1578 * one second (#GST_SECOND) and one hour (3600 * #GST_SECOND)
1579 * @err: a pointer to a #GError. can be %NULL
1581 * Creates a new #GstDiscoverer with the provided timeout.
1583 * Returns: (transfer full): The new #GstDiscoverer.
1584 * If an error occurred when creating the discoverer, @err will be set
1585 * accordingly and %NULL will be returned. If @err is set, the caller must
1586 * free it when no longer needed using g_error_free().
1591 gst_discoverer_new (GstClockTime timeout, GError ** err)
1595 res = g_object_new (GST_TYPE_DISCOVERER, "timeout", timeout, NULL);
1596 if (res->priv->uridecodebin == NULL) {
1598 *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_MISSING_PLUGIN,
1599 "Couldn't create 'uridecodebin' element");
1600 gst_object_unref (res);