/* 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 value which will be set to the result.

 *

 * 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 values array 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];

};

GST_API

GType          gst_control_source_get_type (void);

/* Functions */

GST_API

gboolean       gst_control_source_get_value             (GstControlSource *self, GstClockTime timestamp,

                                                         gdouble *value);

GST_API

gboolean       gst_control_source_get_value_array       (GstControlSource *self, GstClockTime timestamp,

                                                         GstClockTime interval, guint n_values,

                                                         gdouble *values);

#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC

G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstControlSource, gst_object_unref)

#endif

#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC

G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstValueArray, gst_object_unref)

#endif

G_END_DECLS

#endif /* __GST_CONTROL_SOURCE_H__ */