gstreamer/gst/gstcontrolsource.c
Evan Nemerson 6c6bb0e217 introspection: assorted introspection and documentation fixes
These changes are to clean up syntax issues such as missing colons,
missing spaces, etc., and minor issues such as argument names in
headers not matching the implementation and/or documentation.
2012-06-18 13:11:40 +02:00

143 lines
4.5 KiB
C

/* GStreamer
*
* Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>
*
* gstcontrolsource.c: 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstcontrolsource
* @short_description: base class for control source sources
*
* The #GstControlSource is a base class for control value sources that could
* be used by #GstController to get timestamp-value pairs.
*
* A #GstControlSource is used by first getting an instance, binding it to a
* #GParamSpec (for example by using gst_controller_set_control_source()) and
* then by having it used by the #GstController or calling
* gst_control_source_get_value() or gst_control_source_get_value_array().
*
* For implementing a new #GstControlSource one has to implement a
* #GstControlSourceBind method, which will depending on the #GParamSpec set up
* the control source for use and sets the #GstControlSourceGetValue and
* #GstControlSourceGetValueArray functions. These are then used by
* gst_control_source_get_value() or gst_control_source_get_value_array()
* to get values for specific timestamps.
*
*/
#include "gst_private.h"
#include <glib-object.h>
#include <gst/gst.h>
#include "gstcontrolsource.h"
#define GST_CAT_DEFAULT control_source_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
#define _do_init \
GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "gstcontrolsource", 0, \
"dynamic parameter control sources");
G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GstControlSource, gst_control_source,
GST_TYPE_OBJECT, _do_init);
static GObject *gst_control_source_constructor (GType type,
guint n_construct_params, GObjectConstructParam * construct_params);
static void
gst_control_source_class_init (GstControlSourceClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->constructor = gst_control_source_constructor;
}
static void
gst_control_source_init (GstControlSource * self)
{
self->get_value = NULL;
self->get_value_array = NULL;
}
static GObject *
gst_control_source_constructor (GType type, guint n_construct_params,
GObjectConstructParam * construct_params)
{
GObject *self;
self =
G_OBJECT_CLASS (gst_control_source_parent_class)->constructor (type,
n_construct_params, construct_params);
gst_object_ref_sink (self);
return self;
}
/**
* gst_control_source_get_value:
* @self: the #GstControlSource object
* @timestamp: the time for which the value should be returned
* @value: the value
*
* Gets the value for this #GstControlSource at a given timestamp.
*
* Returns: FALSE if the value couldn't be returned, TRUE otherwise.
*/
gboolean
gst_control_source_get_value (GstControlSource * self, GstClockTime timestamp,
gdouble * value)
{
g_return_val_if_fail (GST_IS_CONTROL_SOURCE (self), FALSE);
if (G_LIKELY (self->get_value)) {
return self->get_value (self, timestamp, value);
} else {
GST_ERROR ("Not bound to a specific property yet!");
return FALSE;
}
}
/**
* gst_control_source_get_value_array:
* @self: the #GstControlSource object
* @timestamp: the first timestamp
* @interval: the time steps
* @n_values: the number of values to fetch
* @values: array to put control-values in
*
* Gets an array of values for for this #GstControlSource. Values that are
* undefined contain NANs.
*
* Returns: %TRUE if the given array could be filled, %FALSE otherwise
*/
gboolean
gst_control_source_get_value_array (GstControlSource * self,
GstClockTime timestamp, GstClockTime interval, guint n_values,
gdouble * values)
{
g_return_val_if_fail (GST_IS_CONTROL_SOURCE (self), FALSE);
if (G_LIKELY (self->get_value_array)) {
return self->get_value_array (self, timestamp, interval, n_values, values);
} else {
GST_ERROR ("Not bound to a specific property yet!");
return FALSE;
}
}