gstreamer/gst/gstcontext.h

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/* GStreamer
* Copyright (C) 2013 Collabora Ltd.
* Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>
* Copyright (C) 2013 Sebastian Dröge <slomo@circular-chaos.org>
*
* gstcontext.h: Header for GstContext subsystem
*
* 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.
*/
#ifndef __GST_CONTEXT_H__
#define __GST_CONTEXT_H__
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#include <glib.h>
G_BEGIN_DECLS
typedef struct _GstContext GstContext;
#include <gst/gstminiobject.h>
#include <gst/gststructure.h>
GST_EXPORT GType _gst_context_type;
#define GST_TYPE_CONTEXT (_gst_context_type)
#define GST_IS_CONTEXT(obj) (GST_IS_MINI_OBJECT_TYPE (obj, GST_TYPE_CONTEXT))
#define GST_CONTEXT_CAST(obj) ((GstContext*)(obj))
#define GST_CONTEXT(obj) (GST_CONTEXT_CAST(obj))
GType gst_context_get_type (void);
/* refcounting */
/**
* gst_context_ref:
* @context: the context to ref
*
* Convenience macro to increase the reference count of the context.
*
* Returns: @context (for convenience when doing assignments)
*/
static inline GstContext *
gst_context_ref (GstContext * context)
{
return (GstContext *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (context));
}
/**
* gst_context_unref:
* @context: the context to unref
*
* Convenience macro to decrease the reference count of the context, possibly
* freeing it.
*/
static inline void
gst_context_unref (GstContext * context)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (context));
}
/* copy context */
/**
* gst_context_copy:
* @context: the context to copy
*
* Creates a copy of the context. Returns a copy of the context.
*
* Returns: (transfer full): a new copy of @context.
*
* MT safe
*/
static inline GstContext *
gst_context_copy (const GstContext * context)
{
return GST_CONTEXT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (context)));
}
/**
* gst_context_is_writable:
* @context: a #GstContext
*
* Tests if you can safely write into a context's structure or validly
* modify the seqnum and timestamp fields.
*/
#define gst_context_is_writable(context) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (context))
/**
* gst_context_make_writable:
* @context: (transfer full): the context to make writable
*
* Checks if a context is writable. If not, a writable copy is made and
* returned.
*
* Returns: (transfer full): a context (possibly a duplicate) that is writable.
*
* MT safe
*/
#define gst_context_make_writable(context) GST_CONTEXT_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (context)))
/**
* gst_context_replace:
* @old_context: (inout) (transfer full): pointer to a pointer to a #GstContext
* to be replaced.
* @new_context: (allow-none) (transfer none): pointer to a #GstContext that will
* replace the context pointed to by @old_context.
*
* Modifies a pointer to a #GstContext to point to a different #GstContext. The
* modification is done atomically (so this is useful for ensuring thread safety
* in some cases), and the reference counts are updated appropriately (the old
* context is unreffed, the new one is reffed).
*
* Either @new_context or the #GstContext pointed to by @old_context may be %NULL.
*
* Returns: %TRUE if @new_context was different from @old_context
*/
static inline gboolean
gst_context_replace (GstContext **old_context, GstContext *new_context)
{
return gst_mini_object_replace ((GstMiniObject **) old_context, (GstMiniObject *) new_context);
}
GstContext * gst_context_new (const gchar * context_type,
gboolean persistent) G_GNUC_MALLOC;
const gchar * gst_context_get_context_type (const GstContext * context);
gboolean gst_context_has_context_type (const GstContext * context, const gchar * context_type);
const GstStructure * gst_context_get_structure (const GstContext * context);
GstStructure * gst_context_writable_structure (GstContext * context);
gboolean gst_context_is_persistent (const GstContext * context);
G_END_DECLS
#endif /* __GST_CONTEXT_H__ */