gstreamer/gst/autodetect/gstautovideosrc.c

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/* GStreamer
* (c) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
* (c) 2006 Jan Schmidt <thaytan@noraisin.net>
* (c) 2008 Stefan Kost <ensonic@users.sf.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-autovideosrc
* @see_also: autoaudiosrc, v4l2src, v4lsrc
*
* autovideosrc is a video src that automatically detects an appropriate
* video source to use. It does so by scanning the registry for all elements
* that have <quote>Source</quote> and <quote>Video</quote> in the class field
* of their element information, and also have a non-zero autoplugging rank.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch -v -m autovideosrc ! xvimagesink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstautovideosrc.h"
#include "gstautodetect.h"
/* Properties */
enum
{
PROP_0,
PROP_CAPS,
};
static GstStateChangeReturn
gst_auto_video_src_change_state (GstElement * element,
GstStateChange transition);
static void gst_auto_video_src_dispose (GstAutoVideoSrc * src);
static void gst_auto_video_src_clear_kid (GstAutoVideoSrc * src);
static void gst_auto_video_src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_auto_video_src_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
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#define gst_auto_video_src_parent_class parent_class
G_DEFINE_TYPE (GstAutoVideoSrc, gst_auto_video_src, GST_TYPE_BIN);
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void
gst_auto_video_src_class_init (GstAutoVideoSrcClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *eklass = GST_ELEMENT_CLASS (klass);
gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = (GObjectFinalizeFunc) gst_auto_video_src_dispose;
gobject_class->set_property = gst_auto_video_src_set_property;
gobject_class->get_property = gst_auto_video_src_get_property;
eklass->change_state = GST_DEBUG_FUNCPTR (gst_auto_video_src_change_state);
/**
* GstAutoVideoSrc:filter-caps
*
* This property will filter out candidate sources that can handle the specified
* caps. By default only video sources that support raw rgb and yuv video
* are selected.
*
* This property can only be set before the element goes to the READY state.
*
* Since: 0.10.14
**/
g_object_class_install_property (gobject_class, PROP_CAPS,
g_param_spec_boxed ("filter-caps", "Filter caps",
"Filter src candidates using these caps.", GST_TYPE_CAPS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
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gst_element_class_add_pad_template (eklass,
gst_static_pad_template_get (&src_template));
gst_element_class_set_details_simple (eklass, "Auto video source",
"Source/Video",
"Wrapper video source for automatically detected video source",
"Jan Schmidt <thaytan@noraisin.net>, "
"Stefan Kost <ensonic@users.sf.net>");
}
static void
gst_auto_video_src_dispose (GstAutoVideoSrc * src)
{
gst_auto_video_src_clear_kid (src);
if (src->filter_caps)
gst_caps_unref (src->filter_caps);
src->filter_caps = NULL;
G_OBJECT_CLASS (parent_class)->dispose ((GObject *) src);
}
static void
gst_auto_video_src_clear_kid (GstAutoVideoSrc * src)
{
if (src->kid) {
gst_element_set_state (src->kid, GST_STATE_NULL);
gst_bin_remove (GST_BIN (src), src->kid);
src->kid = NULL;
/* Don't loose SOURCE flag */
GST_OBJECT_FLAG_SET (src, GST_ELEMENT_IS_SOURCE);
}
}
/*
* Hack to make initial linking work; ideally, this'd work even when
* no target has been assigned to the ghostpad yet.
*/
static void
gst_auto_video_src_reset (GstAutoVideoSrc * src)
{
GstPad *targetpad;
/* Remove any existing element */
gst_auto_video_src_clear_kid (src);
/* fakesrc placeholder */
src->kid = gst_element_factory_make ("fakesrc", "tempsrc");
gst_bin_add (GST_BIN (src), src->kid);
/* pad */
targetpad = gst_element_get_static_pad (src->kid, "src");
gst_ghost_pad_set_target (GST_GHOST_PAD (src->pad), targetpad);
gst_object_unref (targetpad);
}
static GstStaticCaps raw_caps =
GST_STATIC_CAPS ("video/x-raw-yuv; video/x-raw-rgb");
static void
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gst_auto_video_src_init (GstAutoVideoSrc * src)
{
src->pad = gst_ghost_pad_new_no_target ("src", GST_PAD_SRC);
gst_element_add_pad (GST_ELEMENT (src), src->pad);
gst_auto_video_src_reset (src);
/* set the default raw video caps */
src->filter_caps = gst_static_caps_get (&raw_caps);
/* mark as source */
GST_OBJECT_FLAG_SET (src, GST_ELEMENT_IS_SOURCE);
}
static gboolean
gst_auto_video_src_factory_filter (GstPluginFeature * feature, gpointer data)
{
guint rank;
const gchar *klass;
/* we only care about element factories */
if (!GST_IS_ELEMENT_FACTORY (feature))
return FALSE;
/* video sources */
klass = gst_element_factory_get_klass (GST_ELEMENT_FACTORY (feature));
if (!(strstr (klass, "Source") && strstr (klass, "Video")))
return FALSE;
/* only select elements with autoplugging rank */
rank = gst_plugin_feature_get_rank (feature);
if (rank < GST_RANK_MARGINAL)
return FALSE;
return TRUE;
}
static gint
gst_auto_video_src_compare_ranks (GstPluginFeature * f1, GstPluginFeature * f2)
{
gint diff;
diff = gst_plugin_feature_get_rank (f2) - gst_plugin_feature_get_rank (f1);
if (diff != 0)
return diff;
return strcmp (gst_plugin_feature_get_name (f2),
gst_plugin_feature_get_name (f1));
}
static GstElement *
gst_auto_video_src_create_element_with_pretty_name (GstAutoVideoSrc * src,
GstElementFactory * factory)
{
GstElement *element;
gchar *name, *marker;
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marker = g_strdup (GST_OBJECT_NAME (factory));
if (g_str_has_suffix (marker, "src"))
marker[strlen (marker) - 4] = '\0';
if (g_str_has_prefix (marker, "gst"))
g_memmove (marker, marker + 3, strlen (marker + 3) + 1);
name = g_strdup_printf ("%s-actual-src-%s", GST_OBJECT_NAME (src), marker);
g_free (marker);
element = gst_element_factory_create (factory, name);
g_free (name);
return element;
}
static GstElement *
gst_auto_video_src_find_best (GstAutoVideoSrc * src)
{
GList *list, *item;
GstElement *choice = NULL;
GstMessage *message = NULL;
GSList *errors = NULL;
GstBus *bus = gst_bus_new ();
GstPad *el_pad = NULL;
GstCaps *el_caps = NULL;
gboolean no_match = TRUE;
list = gst_registry_feature_filter (gst_registry_get_default (),
(GstPluginFeatureFilter) gst_auto_video_src_factory_filter, FALSE, src);
list = g_list_sort (list, (GCompareFunc) gst_auto_video_src_compare_ranks);
GST_LOG_OBJECT (src, "Trying to find usable video devices ...");
for (item = list; item != NULL; item = item->next) {
GstElementFactory *f = GST_ELEMENT_FACTORY (item->data);
GstElement *el;
if ((el = gst_auto_video_src_create_element_with_pretty_name (src, f))) {
GstStateChangeReturn ret;
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GST_DEBUG_OBJECT (src, "Testing %s", GST_OBJECT_NAME (f));
/* If AutoVideoSrc has been provided with filter caps,
* accept only sources that match with the filter caps */
if (src->filter_caps) {
el_pad = gst_element_get_static_pad (GST_ELEMENT (el), "src");
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el_caps = gst_pad_get_caps (el_pad, NULL);
gst_object_unref (el_pad);
GST_DEBUG_OBJECT (src,
"Checking caps: %" GST_PTR_FORMAT " vs. %" GST_PTR_FORMAT,
src->filter_caps, el_caps);
no_match = !gst_caps_can_intersect (src->filter_caps, el_caps);
gst_caps_unref (el_caps);
if (no_match) {
GST_DEBUG_OBJECT (src, "Incompatible caps");
gst_object_unref (el);
continue;
} else {
GST_DEBUG_OBJECT (src, "Found compatible caps");
}
}
gst_element_set_bus (el, bus);
ret = gst_element_set_state (el, GST_STATE_READY);
if (ret == GST_STATE_CHANGE_SUCCESS) {
GST_DEBUG_OBJECT (src, "This worked!");
choice = el;
break;
}
/* collect all error messages */
while ((message = gst_bus_pop_filtered (bus, GST_MESSAGE_ERROR))) {
GST_DEBUG_OBJECT (src, "error message %" GST_PTR_FORMAT, message);
errors = g_slist_append (errors, message);
}
gst_element_set_state (el, GST_STATE_NULL);
gst_object_unref (el);
}
}
GST_DEBUG_OBJECT (src, "done trying");
if (!choice) {
if (errors) {
/* FIXME: we forward the first error for now; but later on it might make
* sense to actually analyse them */
gst_message_ref (GST_MESSAGE (errors->data));
GST_DEBUG_OBJECT (src, "reposting message %p", errors->data);
gst_element_post_message (GST_ELEMENT (src), GST_MESSAGE (errors->data));
} else {
/* send warning message to application and use a fakesrc */
GST_ELEMENT_WARNING (src, RESOURCE, NOT_FOUND, (NULL),
("Failed to find a usable video source"));
choice = gst_element_factory_make ("fakesrc", "fake-video-src");
if (g_object_class_find_property (G_OBJECT_GET_CLASS (choice), "sync"))
g_object_set (choice, "sync", TRUE, NULL);
gst_element_set_state (choice, GST_STATE_READY);
}
}
gst_object_unref (bus);
gst_plugin_feature_list_free (list);
g_slist_foreach (errors, (GFunc) gst_mini_object_unref, NULL);
g_slist_free (errors);
return choice;
}
static gboolean
gst_auto_video_src_detect (GstAutoVideoSrc * src)
{
GstElement *esrc;
GstPad *targetpad;
gst_auto_video_src_clear_kid (src);
/* find element */
GST_DEBUG_OBJECT (src, "Creating new kid");
if (!(esrc = gst_auto_video_src_find_best (src)))
goto no_src;
src->kid = esrc;
gst_bin_add (GST_BIN (src), esrc);
/* attach ghost pad */
GST_DEBUG_OBJECT (src, "Re-assigning ghostpad");
targetpad = gst_element_get_static_pad (src->kid, "src");
if (!gst_ghost_pad_set_target (GST_GHOST_PAD (src->pad), targetpad))
goto target_failed;
gst_object_unref (targetpad);
GST_DEBUG_OBJECT (src, "done changing auto video source");
return TRUE;
/* ERRORS */
no_src:
{
GST_ELEMENT_ERROR (src, LIBRARY, INIT, (NULL),
("Failed to find a supported video source"));
return FALSE;
}
target_failed:
{
GST_ELEMENT_ERROR (src, LIBRARY, INIT, (NULL),
("Failed to set target pad"));
gst_object_unref (targetpad);
return FALSE;
}
}
static GstStateChangeReturn
gst_auto_video_src_change_state (GstElement * element,
GstStateChange transition)
{
GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
if (!gst_auto_video_src_detect (src))
return GST_STATE_CHANGE_FAILURE;
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
gst_auto_video_src_reset (src);
break;
default:
break;
}
return ret;
}
static void
gst_auto_video_src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (object);
switch (prop_id) {
case PROP_CAPS:
if (src->filter_caps)
gst_caps_unref (src->filter_caps);
src->filter_caps = gst_caps_copy (gst_value_get_caps (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_auto_video_src_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (object);
switch (prop_id) {
case PROP_CAPS:{
gst_value_set_caps (value, src->filter_caps);
break;
}
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}