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/* GStreamer
*
* Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>
*
* gstcontrolsource.h: Interface declaration for control sources
*
* 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_CONTROL_SOURCE_H__
#define __GST_CONTROL_SOURCE_H__
#include <gst/gstconfig.h>
#include <glib-object.h>
#include <gst/gstclock.h>
G_BEGIN_DECLS
#define GST_TYPE_CONTROL_SOURCE \
(gst_control_source_get_type())
#define GST_CONTROL_SOURCE(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CONTROL_SOURCE,GstControlSource))
#define GST_CONTROL_SOURCE_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CONTROL_SOURCE,GstControlSourceClass))
#define GST_IS_CONTROL_SOURCE(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_CONTROL_SOURCE))
#define GST_IS_CONTROL_SOURCE_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_CONTROL_SOURCE))
#define GST_CONTROL_SOURCE_GET_CLASS(obj) \
(G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_CONTOL_SOURCE, GstControlSourceClass))
typedef struct _GstControlSource GstControlSource;
typedef struct _GstControlSourceClass GstControlSourceClass;
typedef struct _GstTimedValue GstTimedValue;
typedef struct _GstValueArray GstValueArray;
/**
* GstTimedValue:
* @timestamp: timestamp of the value change
* @value: the corresponding value
*
* Structure for saving a timestamp and a value.
*/
struct _GstTimedValue
{
GstClockTime timestamp;
gdouble value;
};
/**
* GstControlSourceGetValue:
* @self: the #GstControlSource instance
* @timestamp: timestamp for which a value should be calculated
* @value: a #GValue which will be set to the result. It must be initialized to the correct type.
*
* Function for returning a value for a given timestamp.
*
* Returns: %TRUE if the value was successfully calculated.
*
*/
typedef gboolean (* GstControlSourceGetValue) (GstControlSource *self,
GstClockTime timestamp, gdouble *value);
/**
* GstControlSourceGetValueArray:
* @self: the #GstControlSource instance
* @timestamp: timestamp for which a value should be calculated
* @interval: the time spacing between subsequent values
* @n_values: the number of values
* @values: array to put control-values in
*
* Function for returning an array of values for starting at a given timestamp.
*
* Returns: %TRUE if the values were successfully calculated.
*
*/
typedef gboolean (* GstControlSourceGetValueArray) (GstControlSource *self,
GstClockTime timestamp, GstClockTime interval, guint n_values, gdouble *values);
/**
* GstControlSource:
* @get_value: Function for returning a value for a given timestamp
* @get_value_array: Function for returning a #GstValueArray for a given timestamp
*
* The instance structure of #GstControlSource.
*/
struct _GstControlSource {
GstObject parent;
/*< public >*/
GstControlSourceGetValue get_value; /* Returns the value for a property at a given timestamp */
GstControlSourceGetValueArray get_value_array; /* Returns values for a property in a given timespan */
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
/**
* GstControlSourceClass:
* @parent_class: Parent class
*
* The class structure of #GstControlSource.
*/
struct _GstControlSourceClass
{
GstObjectClass parent_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GType gst_control_source_get_type (void);
/* Functions */
gboolean gst_control_source_get_value (GstControlSource *self, GstClockTime timestamp,
gdouble *value);
gboolean gst_control_source_get_value_array (GstControlSource *self, GstClockTime timestamp,
GstClockTime interval, guint n_values,
gdouble *values);
G_END_DECLS
#endif /* __GST_CONTROL_SOURCE_H__ */