gstreamer/gst/gsttaginterface.c

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/* GStreamer
* Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* gsttaginterface.c: interface for tag setting on elements
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gsttaginterface.h"
#include <gobject/gvaluecollector.h>
#include <string.h>
GST_DEBUG_CATEGORY_STATIC (gst_tag_interface_debug);
#define GST_CAT_DEFAULT tag_tag_interface_debug
static GQuark gst_tag_key;
typedef struct {
GstTagMergeMode mode;
GstTagList * list;
} GstTagData;
GType
gst_tag_setter_get_type (void)
{
static GType tag_setter_type = 0;
if (! tag_setter_type) {
static const GTypeInfo tag_setter_info = {
sizeof (GstTagSetterIFace), /* class_size */
NULL, /* base_init */
NULL, /* base_finalize */
NULL,
NULL, /* class_finalize */
NULL, /* class_data */
0,
0,
NULL
};
GST_DEBUG_CATEGORY_INIT (gst_tag_interface_debug, "GstTagInterface", 0, "interfaces for tagging");
tag_setter_type = g_type_register_static (G_TYPE_INTERFACE, "GstTagSetter",
&tag_setter_info, 0);
g_type_interface_add_prerequisite (tag_setter_type, GST_TYPE_ELEMENT);
gst_tag_key = g_quark_from_static_string ("GST_TAG_SETTER");
}
return tag_setter_type;
}
static void
gst_tag_data_free (gpointer p)
{
GstTagData *data = (GstTagData *) p;
if (data->list)
gst_tag_list_free (data->list);
g_free (data);
}
static GstTagData *
gst_tag_setter_get_data (GstTagSetter *setter)
{
GstTagData *data;
data = g_object_get_qdata (G_OBJECT (setter), gst_tag_key);
if (!data) {
data = g_new (GstTagData, 1);
data->list = NULL;
data->mode = GST_TAG_MERGE_KEEP;
g_object_set_qdata_full (G_OBJECT (setter), gst_tag_key, data, gst_tag_data_free);
}
return data;
}
/**
* gst_tag_setter_merge:
* @setter: a #GstTagSetter
* @list: a tag list to merge from
* @mode: the mode to merge with
*
* Merges the given list into the setter's list using the given mode.
*/
void
gst_tag_setter_merge (GstTagSetter *setter, const GstTagList *list, GstTagMergeMode mode)
{
GstTagData *data;
g_return_if_fail (GST_IS_TAG_SETTER (setter));
g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
data = gst_tag_setter_get_data (setter);
if (!data->list) {
data->list = gst_tag_list_copy (list);
} else {
gst_tag_list_merge (data->list, list, mode);
}
}
/**
* gst_tag_setter_add:
* @setter: a #GstTagSetter
* @mode: the mode to use
* @tag: tag to set
* @...: more tag / value pairs to set
*
* Adds the given tag / value pairs on the setter using the given merge mode.
* The list must be terminated with GST_TAG_INVALID.
*/
void
gst_tag_setter_add (GstTagSetter *setter, GstTagMergeMode mode, const gchar *tag, ...)
{
va_list args;
g_return_if_fail (GST_IS_TAG_SETTER (setter));
g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
va_start (args, tag);
gst_tag_setter_add_valist (setter, mode, tag, args);
va_end (args);
}
/**
* gst_tag_setter_add_valist:
* @setter: a #GstTagSetter
* @mode: the mode to use
* @tag: tag to set
* @var_args: tag / value pairs to set
*
* Adds the given tag / value pairs on the setter using the given merge mode.
* The list must be terminated with GST_TAG_INVALID.
*/
void
gst_tag_setter_add_valist (GstTagSetter *setter, GstTagMergeMode mode, const gchar *tag, va_list var_args)
{
GstTagData *data;
g_return_if_fail (GST_IS_TAG_SETTER (setter));
g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
data = gst_tag_setter_get_data (setter);
if (!data->list)
data->list = gst_tag_list_new ();
gst_tag_list_add_valist (data->list, mode, tag, var_args);
}
/**
* gst_tag_setter_get_list:
* @setter: a #GstTagSetter
*
* Retrieves a copy of the current list of tags the setter uses.
* You need to gst_tag_list_free() the list after use.
*
* Returns: a current snapshot of the taglist used in the setter
* or NULL if none is used.
*/
const GstTagList *
gst_tag_setter_get_list (GstTagSetter *setter)
{
g_return_val_if_fail (GST_IS_TAG_SETTER (setter), NULL);
return gst_tag_setter_get_data (setter)->list;
}
/**
* gst_tag_setter_set_merge_mode:
* @setter: a #GstTagSetter
* @overwrite: The mode with which tags are added
*
* Sets the given merge mode that is used for adding tags from events to tags
* specified by this interface. The default is #GST_TAG_MERGE_KEEP, which keeps
* the tags by this interface and discards tags from events.
*/
void
gst_tag_setter_set_merge_mode (GstTagSetter *setter, GstTagMergeMode mode)
{
g_return_if_fail (GST_IS_TAG_SETTER (setter));
g_return_if_fail (GST_TAG_MODE_IS_VALID (mode));
gst_tag_setter_get_data (setter)->mode = mode;
}
/**
* gst_tag_setter_get_merge_mode:
* @setter: a #GstTagSetter
*
* Queries the mode by which tags inside the setter are overwritten by tags
* from events
*
* Returns: the merge mode used inside the element.
*/
GstTagMergeMode
gst_tag_setter_get_merge_mode (GstTagSetter *setter)
{
g_return_val_if_fail (GST_IS_TAG_SETTER (setter), FALSE);
return gst_tag_setter_get_data (setter)->mode;
}