gstreamer/gst/camerabin2/camerabingeneral.c

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/*
* GStreamer
* Copyright (C) 2008 Nokia Corporation <multimedia@maemo.org>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:camerabingeneral
* @title: GstCameraBin2
* @short_description: helper functions for #GstCameraBin2 and it's modules
*
* Common helper functions for #GstCameraBin2, #GstCameraBin2Image and
* #GstCameraBin2Video.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <glib.h>
#include <gst/basecamerabinsrc/gstbasecamerasrc.h>
#include <gst/gst-i18n-plugin.h>
#include "camerabingeneral.h"
/**
* gst_camerabin_add_element:
* @bin: add an element to this bin
* @new_elem: new element to be added
*
* Adds given element to given @bin. Looks for an unconnected src pad
* from the @bin and links the element to it. Raises an error if adding
* or linking failed. Unrefs the element in the case of an error.
*
* Returns: %TRUE if adding and linking succeeded, %FALSE otherwise.
*/
gboolean
gst_camerabin_add_element (GstBin * bin, GstElement * new_elem)
{
return gst_camerabin_add_element_full (bin, NULL, new_elem, NULL);
}
/**
* gst_camerabin_add_element_full:
* @bin: add an element to this bin
* @srcpad: src pad name, or NULL for any
* @new_elem: new element to be added
* @dstpad: dst pad name, or NULL for any
*
* Adds given element to given @bin. Looks for an unconnected src pad
* (with name @srcpad, if specified) from the @bin and links the element
* to it. Raises an error if adding or linking failed. Unrefs the element
* in the case of an error.
*
* Returns: %TRUE if adding and linking succeeded, %FALSE otherwise.
*/
gboolean
gst_camerabin_add_element_full (GstBin * bin, const gchar * srcpad,
GstElement * new_elem, const gchar * dstpad)
{
gboolean ret;
g_return_val_if_fail (bin, FALSE);
g_return_val_if_fail (new_elem, FALSE);
ret = gst_camerabin_try_add_element (bin, srcpad, new_elem, dstpad);
if (!ret) {
gchar *elem_name = gst_element_get_name (new_elem);
GST_ELEMENT_ERROR (bin, CORE, NEGOTIATION, (NULL),
("linking %s failed", elem_name));
g_free (elem_name);
gst_object_unref (new_elem);
}
return ret;
}
/**
* gst_camerabin_try_add_element:
* @bin: tries adding an element to this bin
* @srcpad: src pad name, or NULL for any
* @new_elem: new element to be added
* @dstpad: dst pad name, or NULL for any
*
* Adds given element to given @bin. Looks for an unconnected src pad
* (with name @srcpad, if specified) from the @bin and links the element to
* it.
*
* Returns: %TRUE if adding and linking succeeded, %FALSE otherwise.
*/
gboolean
gst_camerabin_try_add_element (GstBin * bin, const gchar * srcpad,
GstElement * new_elem, const gchar * dstpad)
{
GstPad *bin_pad;
GstElement *bin_elem;
gboolean ret = TRUE;
g_return_val_if_fail (bin, FALSE);
g_return_val_if_fail (new_elem, FALSE);
/* Get pads for linking */
bin_pad = gst_bin_find_unlinked_pad (bin, GST_PAD_SRC);
/* Add to bin */
gst_bin_add (GST_BIN (bin), new_elem);
/* Link, if unconnected pad was found, otherwise just add it to bin */
if (bin_pad) {
GST_DEBUG_OBJECT (bin, "linking %s to %s:%s", GST_OBJECT_NAME (new_elem),
GST_DEBUG_PAD_NAME (bin_pad));
bin_elem = gst_pad_get_parent_element (bin_pad);
gst_object_unref (bin_pad);
if (!gst_element_link_pads_full (bin_elem, srcpad, new_elem, dstpad,
GST_PAD_LINK_CHECK_CAPS)) {
gst_object_ref (new_elem);
gst_bin_remove (bin, new_elem);
ret = FALSE;
}
gst_object_unref (bin_elem);
} else {
GST_INFO_OBJECT (bin, "no unlinked source pad in bin");
}
return ret;
}
/**
* gst_camerabin_create_and_add_element:
* @bin: tries adding an element to this bin
* @elem_name: name of the element to be created
* @instance_name: name of the instance of the element to be created
*
* Creates an element according to given name and
* adds it to given @bin. Looks for an unconnected src pad
* from the @bin and links the element to it.
*
* Returns: pointer to the new element if successful, NULL otherwise.
*/
GstElement *
gst_camerabin_create_and_add_element (GstBin * bin, const gchar * elem_name,
const gchar * instance_name)
{
GstElement *new_elem;
g_return_val_if_fail (bin, FALSE);
g_return_val_if_fail (elem_name, FALSE);
new_elem = gst_element_factory_make (elem_name, instance_name);
if (!new_elem) {
GST_ELEMENT_ERROR (bin, CORE, MISSING_PLUGIN,
(_("Missing element '%s' - check your GStreamer installation."),
elem_name), (NULL));
} else if (!gst_camerabin_add_element (bin, new_elem)) {
new_elem = NULL;
}
return new_elem;
}
/* try to change the state of an element. This function returns the element
* when the state change could be performed. When this function returns NULL
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* an error occurred and the element is unreffed. */
static GstElement *
try_element (GstElement * bin, GstElement * element)
{
GstStateChangeReturn ret;
if (element) {
ret = gst_element_set_state (element, GST_STATE_READY);
if (ret == GST_STATE_CHANGE_FAILURE) {
GST_DEBUG_OBJECT (bin, "failed state change..");
gst_element_set_state (element, GST_STATE_NULL);
gst_object_unref (element);
element = NULL;
}
}
return element;
}
GstElement *
gst_camerabin_setup_default_element (GstBin * bin, GstElement * user_elem,
const gchar * auto_elem_name, const gchar * default_elem_name,
const gchar * instance_name)
{
GstElement *elem;
if (user_elem) {
GST_DEBUG_OBJECT (bin, "trying configured element");
elem = try_element (GST_ELEMENT_CAST (bin), gst_object_ref (user_elem));
} else {
/* only try fallback if no specific sink was chosen */
GST_DEBUG_OBJECT (bin, "trying %s", auto_elem_name);
elem = gst_element_factory_make (auto_elem_name, instance_name);
elem = try_element (GST_ELEMENT_CAST (bin), elem);
if (elem == NULL) {
/* if default sink from config.h is different then try it too */
if (strcmp (default_elem_name, auto_elem_name)) {
GST_DEBUG_OBJECT (bin, "trying %s", default_elem_name);
elem = gst_element_factory_make (default_elem_name, instance_name);
elem = try_element (GST_ELEMENT_CAST (bin), elem);
}
}
}
return elem;
}
/**
* gst_camerabin_remove_elements_from_bin:
* @bin: removes all elements from this bin
*
* Removes all elements from this @bin.
*/
void
gst_camerabin_remove_elements_from_bin (GstBin * bin)
{
GstIterator *iter = NULL;
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GValue value = { 0 };
GstElement *elem = NULL;
gboolean done = FALSE;
iter = gst_bin_iterate_elements (bin);
while (!done) {
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switch (gst_iterator_next (iter, &value)) {
case GST_ITERATOR_OK:
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elem = (GstElement *) g_value_get_object (&value);
gst_bin_remove (bin, elem);
gst_element_set_state (GST_ELEMENT (elem), GST_STATE_NULL);
/* Iterator increased the element refcount, so unref */
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g_value_unset (&value);
break;
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
case GST_ITERATOR_ERROR:
GST_WARNING_OBJECT (bin, "error in iterating elements");
done = TRUE;
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
}