gstreamer/libs/gst/controller/gsthelper.c

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/* GStreamer
*
* Copyright (C) <2005> Stefan Kost <ensonic at users dot sf dot net>
*
* gsthelper.c: GObject convenience methods for using dynamic properties
*
* 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:gstcontrollergobject
* @short_description: #GObject convinience methods for using dynamic properties
* @see_also: #GstController
*
* These methods allow to use some #GstController functionallity directly from
* the #GObject class.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdarg.h>
#include "gstcontrollerprivate.h"
#include "gstcontroller.h"
#define GST_CAT_DEFAULT gst_controller_debug
GST_DEBUG_CATEGORY_EXTERN (GST_CAT_DEFAULT);
extern GQuark __gst_controller_key;
/**
* gst_object_control_properties:
* @object: the object of which some properties should be controlled
* @...: %NULL terminated list of property names that should be controlled
*
* Convenience function for GObject
*
* Creates a GstController that allows you to dynamically control one, or more, GObject properties.
* If the given GObject already has a GstController, it adds the given properties to the existing
* controller and returns that controller.
*
* Returns: The GstController with which the user can control the given properties dynamically or NULL if
* one or more of the given properties aren't available, or cannot be controlled, for the given element.
* Since: 0.9
*/
GstController *
gst_object_control_properties (GObject * object, ...)
{
GstController *ctrl;
va_list var_args;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
va_start (var_args, object);
ctrl = gst_controller_new_valist (object, var_args);
va_end (var_args);
return (ctrl);
}
/**
* gst_object_uncontrol_properties:
* @object: the object of which some properties should not be controlled anymore
* @...: %NULL terminated list of property names that should be controlled
*
* Convenience function for GObject
*
* Removes the given element's properties from it's controller
*
* Returns: %FALSE if one of the given property names isn't handled by the
* controller, %TRUE otherwise
* Since: 0.9
*/
gboolean
gst_object_uncontrol_properties (GObject * object, ...)
{
gboolean res = FALSE;
GstController *ctrl;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
if ((ctrl = g_object_get_qdata (object, __gst_controller_key))) {
va_list var_args;
va_start (var_args, object);
res = gst_controller_remove_properties_valist (ctrl, var_args);
va_end (var_args);
}
return (res);
}
/**
* gst_object_get_controller:
* @object: the object that has controlled properties
*
* Gets the controller for the given GObject
*
* Returns: the controller handling some of the given element's properties, %NULL if no controller
* Since: 0.9
*/
GstController *
gst_object_get_controller (GObject * object)
{
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
return (g_object_get_qdata (object, __gst_controller_key));
}
/**
* gst_object_set_controller:
* @object: the object that should get the controller
* @controller: the controller object to plug in
*
* Sets the controller on the given GObject
*
* Returns: %FALSE if the GObject already has an controller, %TRUE otherwise
* Since: 0.9
*/
gboolean
gst_object_set_controller (GObject * object, GstController * controller)
{
GstController *ctrl;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
g_return_val_if_fail (controller, FALSE);
if (!(ctrl = g_object_get_qdata (object, __gst_controller_key))) {
g_object_set_qdata (object, __gst_controller_key, controller);
return (TRUE);
}
return (FALSE);
}
/**
* gst_object_sync_values:
* @object: the object that has controlled properties
* @timestamp: the time that should be processed
*
* Convenience function for GObject
*
* Returns: same thing as gst_controller_sync_values()
* Since: 0.9
*/
gboolean
gst_object_sync_values (GObject * object, GstClockTime timestamp)
{
GstController *ctrl = NULL;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
if ((ctrl = g_object_get_qdata (object, __gst_controller_key))) {
return gst_controller_sync_values (ctrl, timestamp);
}
return (FALSE);
}
/**
* gst_object_get_value_arrays:
* @object: the object that has controlled properties
* @timestamp: the time that should be processed
* @value_arrays: list to return the control-values in
*
* Function to be able to get an array of values for one or more given element
* properties.
*
* If the GstValueArray->values array in list nodes is NULL, it will be created
* by the function.
* The type of the values in the array are the same as the property's type.
*
* The g_object_* functions are just convenience functions for GObject
*
* Returns: %TRUE if the given array(s) could be filled, %FALSE otherwise
* Since: 0.9
*/
gboolean
gst_object_get_value_arrays (GObject * object, GstClockTime timestamp,
GSList * value_arrays)
{
GstController *ctrl;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
if ((ctrl = g_object_get_qdata (object, __gst_controller_key))) {
return gst_controller_get_value_arrays (ctrl, timestamp, value_arrays);
}
return (FALSE);
}
/**
* gst_object_get_value_array:
* @object: the object that has controlled properties
* @timestamp: the time that should be processed
* @value_array: array to put control-values in
*
* Function to be able to get an array of values for one element properties
*
* If the GstValueArray->values array is NULL, it will be created by the function.
* The type of the values in the array are the same as the property's type.
*
* The g_object_* functions are just convenience functions for GObject
*
* Returns: %TRUE if the given array(s) could be filled, %FALSE otherwise
* Since: 0.9
*/
gboolean
gst_object_get_value_array (GObject * object, GstClockTime timestamp,
GstValueArray * value_array)
{
GstController *ctrl;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
if ((ctrl = g_object_get_qdata (object, __gst_controller_key))) {
return gst_controller_get_value_array (ctrl, timestamp, value_array);
}
return (FALSE);
}
/**
* gst_object_get_control_rate:
* @object: the object that has controlled properties
*
* Obtain the control-rate for this @object. Audio processing #GstElement
* objects will use this rate to sub-divide their processing loop and call
* gst_object_sync_values() inbetween. The length of the processing segment
* should be sampling-rate/control-rate.
*
* If the @object is not under property control, this will return 0. This allows
* the element to avoid the sub-dividing.
*
* The control-rate is not expected to change if the elemnt is in
* %GST_STATE_PAUSED or %GST_STATE_PLAYING.
*
* Returns: the control rate
* Since: 0.10.10
*/
guint
gst_object_get_control_rate (GObject * object)
{
GstController *ctrl;
guint control_rate = 0;
g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
if ((ctrl = g_object_get_qdata (object, __gst_controller_key))) {
g_object_get (ctrl, "control-rate", &control_rate, NULL);
}
return (control_rate);
}
/**
* gst_object_set_control_rate:
* @object: the object that has controlled properties
* @control_rate: the new control-rate (1 .. sampling_rate)
*
* Change the control-rate for this @object. Audio processing #GstElement
* objects will use this rate to sub-divide their processing loop and call
* gst_object_sync_values() inbetween. The length of the processing segment
* should be sampling-rate/control-rate.
*
* The control-rate should not change if the elemnt is in %GST_STATE_PAUSED or
* %GST_STATE_PLAYING.
*
* Since: 0.10.10
*/
void
gst_object_set_control_rate (GObject * object, guint control_rate)
{
GstController *ctrl;
g_return_if_fail (G_IS_OBJECT (object));
if ((ctrl = g_object_get_qdata (object, __gst_controller_key))) {
g_object_set (ctrl, "control-rate", control_rate, NULL);
}
}