gstreamer/subprojects/gst-editing-services/plugins/nle/nleoperation.c

868 lines
24 KiB
C

/* GStreamer
* Copyright (C) 2001 Wim Taymans <wim.taymans@gmail.com>
* 2004-2008 Edward Hervey <bilboed@bilboed.com>
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "nle.h"
/**
* SECTION:element-nleoperation
*
* A NleOperation performs a transformation or mixing operation on the
* data from one or more #NleSources, which is used to implement filters or
* effects.
*
* ## Time Effects
*
* An #nleoperation that wraps a #GstElement that transforms seek and
* segment times is considered a time effect. Nle only tries to support
* time effect's whose overall seek transformation:
*
* + Maps the time `0` to `0`. So initial time-shifting effects are
* excluded (the #NleObject:inpoint can sometimes be used instead).
* + Is monotonically increasing. So reversing effects, and effects that
* jump backwards in the stream are excluded.
* + Can handle a reasonable #GstClockTime, relative to the project. So
* this would exclude a time effect with an extremely large speed-up
* that would cause the converted #GstClockTime seeks to overflow.
* + Is 'continuously reversible'. This essentially means that for every
* seek position found on the sink pad of the element, we can, to 'good
* enough' accuracy, calculate the corresponding seek position that was
* received on the source pad. Moreover, this calculation should
* correspond to how the element transforms its #GstSegment
* @time field. This is needed so that a seek can result in an accurate
* segment.
*
* Note that a constant-rate-change effect that is not extremely fast or
* slow would satisfy these conditions.
*
* For such a time effect, they should be configured in nle such that:
*
* + Their #NleObject:inpoint is `0`. Otherwise this will introduce
* seeking problems in its #nlecomposition.
* + They must share the same #NleObject:start and
* #NleObject:duration as all nleobjects of lower priority in its
* #nlecomposition. Otherwise this will introduce jumps in playback.
*
* Note that, at the moment, nle only converts the #GstSegment
* @time field which means the other fields, such as @start and @stop, can
* end up with non-meaningful values when time effects are involved.
* Moreover, it does not convert #GstBuffer times either, which can result
* in them having non-meaningful values. In particular, this means that
* #GstControlBinding-s will not work well with #nlecomposition-s when
* they include time effects.
*/
static GstStaticPadTemplate nle_operation_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate nle_operation_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink%d",
GST_PAD_SINK,
GST_PAD_REQUEST,
GST_STATIC_CAPS_ANY);
GST_DEBUG_CATEGORY_STATIC (nleoperation);
#define GST_CAT_DEFAULT nleoperation
#define _do_init \
GST_DEBUG_CATEGORY_INIT (nleoperation, "nleoperation", GST_DEBUG_FG_BLUE | GST_DEBUG_BOLD, "GNonLin Operation element");
#define nle_operation_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (NleOperation, nle_operation, NLE_TYPE_OBJECT,
_do_init);
enum
{
ARG_0,
ARG_SINKS,
};
enum
{
INPUT_PRIORITY_CHANGED,
LAST_SIGNAL
};
static guint nle_operation_signals[LAST_SIGNAL] = { 0 };
static void nle_operation_dispose (GObject * object);
static void nle_operation_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void nle_operation_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean nle_operation_prepare (NleObject * object);
static gboolean nle_operation_cleanup (NleObject * object);
static gboolean nle_operation_add_element (GstBin * bin, GstElement * element);
static gboolean nle_operation_remove_element (GstBin * bin,
GstElement * element);
static GstPad *nle_operation_request_new_pad (GstElement * element,
GstPadTemplate * templ, const gchar * name, const GstCaps * caps);
static void nle_operation_release_pad (GstElement * element, GstPad * pad);
static void synchronize_sinks (NleOperation * operation);
static gboolean remove_sink_pad (NleOperation * operation, GstPad * sinkpad);
static gboolean
nle_operation_send_event (GstElement * element, GstEvent * event)
{
gboolean res = TRUE;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEEK:
nle_object_seek_all_children (NLE_OBJECT (element), event);
break;
default:
res = GST_ELEMENT_CLASS (parent_class)->send_event (element, event);
break;
}
return res;
}
static void
nle_operation_class_init (NleOperationClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstBinClass *gstbin_class = (GstBinClass *) klass;
GstElementClass *gstelement_class = (GstElementClass *) klass;
NleObjectClass *nleobject_class = (NleObjectClass *) klass;
gst_element_class_set_static_metadata (gstelement_class, "GNonLin Operation",
"Filter/Editor",
"Encapsulates filters/effects for use with NLE Objects",
"Wim Taymans <wim.taymans@gmail.com>, Edward Hervey <bilboed@bilboed.com>");
gobject_class->dispose = GST_DEBUG_FUNCPTR (nle_operation_dispose);
gobject_class->set_property = GST_DEBUG_FUNCPTR (nle_operation_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (nle_operation_get_property);
/**
* NleOperation:sinks:
*
* Specifies the number of sink pads the operation should provide.
* If the sinks property is -1 (the default) pads are only created as
* demanded via `get_request_pad()` calls on the element.
*/
g_object_class_install_property (gobject_class, ARG_SINKS,
g_param_spec_int ("sinks", "Sinks",
"Number of input sinks (-1 for automatic handling)", -1, G_MAXINT, -1,
G_PARAM_READWRITE));
/**
* NleOperation:input-priority-changed:
* @pad: The operation's input pad whose priority changed.
* @priority: The new priority
*
* Signals that the @priority of the stream being fed to the given @pad
* might have changed.
*/
nle_operation_signals[INPUT_PRIORITY_CHANGED] =
g_signal_new ("input-priority-changed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (NleOperationClass,
input_priority_changed), NULL, NULL, NULL,
G_TYPE_NONE, 2, GST_TYPE_PAD, G_TYPE_UINT);
gstelement_class->request_new_pad =
GST_DEBUG_FUNCPTR (nle_operation_request_new_pad);
gstelement_class->release_pad = GST_DEBUG_FUNCPTR (nle_operation_release_pad);
gstelement_class->send_event = GST_DEBUG_FUNCPTR (nle_operation_send_event);
gstbin_class->add_element = GST_DEBUG_FUNCPTR (nle_operation_add_element);
gstbin_class->remove_element =
GST_DEBUG_FUNCPTR (nle_operation_remove_element);
nleobject_class->prepare = GST_DEBUG_FUNCPTR (nle_operation_prepare);
nleobject_class->cleanup = GST_DEBUG_FUNCPTR (nle_operation_cleanup);
gst_element_class_add_static_pad_template (gstelement_class,
&nle_operation_src_template);
gst_element_class_add_static_pad_template (gstelement_class,
&nle_operation_sink_template);
}
static void
nle_operation_dispose (GObject * object)
{
NleOperation *oper = (NleOperation *) object;
GST_DEBUG_OBJECT (object, "Disposing of source pad");
nle_object_ghost_pad_set_target (NLE_OBJECT (object),
NLE_OBJECT (object)->srcpad, NULL);
GST_DEBUG_OBJECT (object, "Disposing of sink pad(s)");
while (oper->sinks) {
GstPad *ghost = (GstPad *) oper->sinks->data;
remove_sink_pad (oper, ghost);
}
GST_DEBUG_OBJECT (object, "Done, calling parent class ::dispose()");
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
nle_operation_reset (NleOperation * operation)
{
operation->num_sinks = 1;
operation->realsinks = 0;
}
static void
nle_operation_init (NleOperation * operation)
{
GST_OBJECT_FLAG_SET (operation, NLE_OBJECT_OPERATION);
nle_operation_reset (operation);
operation->element = NULL;
}
static gboolean
element_is_valid_filter (GstElement * element, gboolean * isdynamic)
{
gboolean havesink = FALSE;
gboolean havesrc = FALSE;
gboolean done = FALSE;
GstIterator *pads;
GValue item = { 0, };
if (isdynamic)
*isdynamic = FALSE;
pads = gst_element_iterate_pads (element);
while (!done) {
switch (gst_iterator_next (pads, &item)) {
case GST_ITERATOR_OK:
{
GstPad *pad = g_value_get_object (&item);
if (gst_pad_get_direction (pad) == GST_PAD_SRC)
havesrc = TRUE;
else if (gst_pad_get_direction (pad) == GST_PAD_SINK)
havesink = TRUE;
g_value_reset (&item);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (pads);
havesrc = FALSE;
havesink = FALSE;
break;
default:
/* ERROR and DONE */
done = TRUE;
break;
}
}
g_value_unset (&item);
gst_iterator_free (pads);
/* just look at the element's class, not the factory, since there might
* not be a factory (in case of python elements) or the factory is the
* wrong one (in case of a GstBin sub-class) and doesn't have complete
* information. */
{
GList *tmp =
gst_element_class_get_pad_template_list (GST_ELEMENT_GET_CLASS
(element));
while (tmp) {
GstPadTemplate *template = (GstPadTemplate *) tmp->data;
if (template->direction == GST_PAD_SRC)
havesrc = TRUE;
else if (template->direction == GST_PAD_SINK) {
if (!havesink && (template->presence == GST_PAD_REQUEST) && isdynamic)
*isdynamic = TRUE;
havesink = TRUE;
}
tmp = tmp->next;
}
}
return (havesink && havesrc);
}
/*
* get_src_pad:
* element: a #GstElement
*
* Returns: The src pad for the given element. A reference was added to the
* returned pad, remove it when you don't need that pad anymore.
* Returns NULL if there's no source pad.
*/
static GstPad *
get_src_pad (GstElement * element)
{
GstIterator *it;
GstIteratorResult itres;
GValue item = { 0, };
GstPad *srcpad = NULL;
it = gst_element_iterate_src_pads (element);
itres = gst_iterator_next (it, &item);
if (itres != GST_ITERATOR_OK) {
GST_DEBUG ("%s doesn't have a src pad !", GST_ELEMENT_NAME (element));
} else {
srcpad = g_value_get_object (&item);
gst_object_ref (srcpad);
}
g_value_reset (&item);
gst_iterator_free (it);
return srcpad;
}
/* get_nb_static_sinks:
*
* Returns : The number of static sink pads of the controlled element.
*/
static guint
get_nb_static_sinks (NleOperation * oper)
{
GstIterator *sinkpads;
gboolean done = FALSE;
guint nbsinks = 0;
GValue item = { 0, };
sinkpads = gst_element_iterate_sink_pads (oper->element);
while (!done) {
switch (gst_iterator_next (sinkpads, &item)) {
case GST_ITERATOR_OK:{
nbsinks++;
g_value_unset (&item);
}
break;
case GST_ITERATOR_RESYNC:
nbsinks = 0;
gst_iterator_resync (sinkpads);
break;
default:
/* ERROR and DONE */
done = TRUE;
break;
}
}
g_value_reset (&item);
gst_iterator_free (sinkpads);
GST_DEBUG ("We found %d static sinks", nbsinks);
return nbsinks;
}
static gboolean
nle_operation_add_element (GstBin * bin, GstElement * element)
{
NleOperation *operation = (NleOperation *) bin;
gboolean res = FALSE;
gboolean isdynamic;
GST_DEBUG_OBJECT (bin, "element:%s", GST_ELEMENT_NAME (element));
if (operation->element) {
GST_WARNING_OBJECT (operation,
"We already control an element : %s , remove it first",
GST_OBJECT_NAME (operation->element));
} else {
if (!element_is_valid_filter (element, &isdynamic)) {
GST_WARNING_OBJECT (operation,
"Element %s is not a valid filter element",
GST_ELEMENT_NAME (element));
} else {
if ((res = GST_BIN_CLASS (parent_class)->add_element (bin, element))) {
GstPad *srcpad;
srcpad = get_src_pad (element);
if (!srcpad)
return FALSE;
operation->element = element;
operation->dynamicsinks = isdynamic;
nle_object_ghost_pad_set_target (NLE_OBJECT (operation),
NLE_OBJECT (operation)->srcpad, srcpad);
/* Remove the reference get_src_pad gave us */
gst_object_unref (srcpad);
/* Figure out number of static sink pads */
operation->num_sinks = get_nb_static_sinks (operation);
/* Finally sync the ghostpads with the real pads */
synchronize_sinks (operation);
}
}
}
return res;
}
static gboolean
nle_operation_remove_element (GstBin * bin, GstElement * element)
{
NleOperation *operation = (NleOperation *) bin;
gboolean res = FALSE;
if (operation->element) {
if ((res = GST_BIN_CLASS (parent_class)->remove_element (bin, element)))
operation->element = NULL;
} else {
GST_WARNING_OBJECT (bin,
"Element %s is not the one controlled by this operation",
GST_ELEMENT_NAME (element));
}
return res;
}
static void
nle_operation_set_sinks (NleOperation * operation, guint sinks)
{
/* FIXME : Check if sinkpad of element is on-demand .... */
operation->num_sinks = sinks;
synchronize_sinks (operation);
}
static void
nle_operation_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
NleOperation *operation = (NleOperation *) object;
switch (prop_id) {
case ARG_SINKS:
nle_operation_set_sinks (operation, g_value_get_int (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
nle_operation_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
NleOperation *operation = (NleOperation *) object;
switch (prop_id) {
case ARG_SINKS:
g_value_set_int (value, operation->num_sinks);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/*
* Returns the first unused sink pad of the controlled element.
* Only use with static element. Unref after usage.
* Returns NULL if there's no more unused sink pads.
*/
static GstPad *
get_unused_static_sink_pad (NleOperation * operation)
{
GstIterator *pads;
gboolean done = FALSE;
GValue item = { 0, };
GstPad *ret = NULL;
if (!operation->element)
return NULL;
pads = gst_element_iterate_pads (operation->element);
while (!done) {
switch (gst_iterator_next (pads, &item)) {
case GST_ITERATOR_OK:
{
GstPad *pad = g_value_get_object (&item);
if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
GList *tmp;
gboolean istaken = FALSE;
/* 1. figure out if one of our sink ghostpads has this pad as target */
for (tmp = operation->sinks; tmp; tmp = tmp->next) {
GstGhostPad *gpad = (GstGhostPad *) tmp->data;
GstPad *target = gst_ghost_pad_get_target (gpad);
GST_LOG ("found ghostpad with target %s:%s",
GST_DEBUG_PAD_NAME (target));
if (target) {
if (target == pad)
istaken = TRUE;
gst_object_unref (target);
}
}
/* 2. if not taken, return that pad */
if (!istaken) {
gst_object_ref (pad);
ret = pad;
done = TRUE;
}
}
g_value_reset (&item);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (pads);
break;
default:
/* ERROR and DONE */
done = TRUE;
break;
}
}
g_value_unset (&item);
gst_iterator_free (pads);
if (ret)
GST_DEBUG_OBJECT (operation, "found free sink pad %s:%s",
GST_DEBUG_PAD_NAME (ret));
else
GST_DEBUG_OBJECT (operation, "Couldn't find an unused sink pad");
return ret;
}
GstPad *
get_unlinked_sink_ghost_pad (NleOperation * operation)
{
GstIterator *pads;
gboolean done = FALSE;
GValue item = { 0, };
GstPad *ret = NULL;
if (!operation->element)
return NULL;
pads = gst_element_iterate_sink_pads ((GstElement *) operation);
while (!done) {
switch (gst_iterator_next (pads, &item)) {
case GST_ITERATOR_OK:
{
GstPad *pad = g_value_get_object (&item);
GstPad *peer = gst_pad_get_peer (pad);
if (peer == NULL) {
ret = pad;
gst_object_ref (ret);
done = TRUE;
} else {
gst_object_unref (peer);
}
g_value_reset (&item);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (pads);
break;
default:
/* ERROR and DONE */
done = TRUE;
break;
}
}
g_value_unset (&item);
gst_iterator_free (pads);
if (ret)
GST_DEBUG_OBJECT (operation, "found unlinked ghost sink pad %s:%s",
GST_DEBUG_PAD_NAME (ret));
else
GST_DEBUG_OBJECT (operation, "Couldn't find an unlinked ghost sink pad");
return ret;
}
static GstPad *
get_request_sink_pad (NleOperation * operation)
{
GstPad *pad = NULL;
GList *templates;
if (!operation->element)
return NULL;
templates = gst_element_class_get_pad_template_list
(GST_ELEMENT_GET_CLASS (operation->element));
for (; templates; templates = templates->next) {
GstPadTemplate *templ = (GstPadTemplate *) templates->data;
GST_LOG_OBJECT (operation->element, "Trying template %s",
GST_PAD_TEMPLATE_NAME_TEMPLATE (templ));
if ((GST_PAD_TEMPLATE_DIRECTION (templ) == GST_PAD_SINK) &&
(GST_PAD_TEMPLATE_PRESENCE (templ) == GST_PAD_REQUEST)) {
pad =
gst_element_request_pad_simple (operation->element,
GST_PAD_TEMPLATE_NAME_TEMPLATE (templ));
if (pad)
break;
}
}
return pad;
}
static GstPad *
add_sink_pad (NleOperation * operation)
{
GstPad *gpad = NULL;
GstPad *ret = NULL;
if (!operation->element)
return NULL;
/* FIXME : implement */
GST_LOG_OBJECT (operation, "element:%s , dynamicsinks:%d",
GST_ELEMENT_NAME (operation->element), operation->dynamicsinks);
if (!operation->dynamicsinks) {
/* static sink pads */
ret = get_unused_static_sink_pad (operation);
if (ret) {
gpad = nle_object_ghost_pad ((NleObject *) operation, GST_PAD_NAME (ret),
ret);
gst_object_unref (ret);
}
}
if (!gpad) {
/* request sink pads */
ret = get_request_sink_pad (operation);
if (ret) {
gpad = nle_object_ghost_pad ((NleObject *) operation, GST_PAD_NAME (ret),
ret);
gst_object_unref (ret);
}
}
if (gpad) {
operation->sinks = g_list_append (operation->sinks, gpad);
operation->realsinks++;
GST_DEBUG ("Created new pad %s:%s ghosting %s:%s",
GST_DEBUG_PAD_NAME (gpad), GST_DEBUG_PAD_NAME (ret));
} else {
GST_WARNING ("Couldn't find a usable sink pad!");
}
return gpad;
}
static gboolean
remove_sink_pad (NleOperation * operation, GstPad * sinkpad)
{
gboolean ret = TRUE;
gboolean need_unref = FALSE;
GST_DEBUG ("sinkpad %s:%s", GST_DEBUG_PAD_NAME (sinkpad));
/*
We can't remove any random pad.
We should remove an unused pad ... which is hard to figure out in a
thread-safe way.
*/
if ((sinkpad == NULL) && operation->dynamicsinks) {
/* Find an unlinked sinkpad */
if ((sinkpad = get_unlinked_sink_ghost_pad (operation)) == NULL) {
ret = FALSE;
goto beach;
}
need_unref = TRUE;
}
if (sinkpad) {
GstPad *target = gst_ghost_pad_get_target ((GstGhostPad *) sinkpad);
if (target) {
/* release the target pad */
nle_object_ghost_pad_set_target ((NleObject *) operation, sinkpad, NULL);
if (operation->dynamicsinks)
gst_element_release_request_pad (operation->element, target);
gst_object_unref (target);
}
operation->sinks = g_list_remove (operation->sinks, sinkpad);
nle_object_remove_ghost_pad ((NleObject *) operation, sinkpad);
if (need_unref)
gst_object_unref (sinkpad);
operation->realsinks--;
}
beach:
return ret;
}
static void
synchronize_sinks (NleOperation * operation)
{
GST_DEBUG_OBJECT (operation, "num_sinks:%d , realsinks:%d, dynamicsinks:%d",
operation->num_sinks, operation->realsinks, operation->dynamicsinks);
if (operation->num_sinks == operation->realsinks)
return;
if (operation->num_sinks > operation->realsinks) {
while (operation->num_sinks > operation->realsinks) /* Add pad */
if (!(add_sink_pad (operation))) {
break;
}
} else {
/* Remove pad */
/* FIXME, which one do we remove ? :) */
while (operation->num_sinks < operation->realsinks)
if (!remove_sink_pad (operation, NULL))
break;
}
}
static gboolean
nle_operation_prepare (NleObject * object)
{
/* Prepare the pads */
synchronize_sinks ((NleOperation *) object);
return TRUE;
}
static gboolean
nle_operation_cleanup (NleObject * object)
{
NleOperation *oper = (NleOperation *) object;
if (oper->dynamicsinks) {
GST_DEBUG ("Resetting dynamic sinks");
nle_operation_set_sinks (oper, 0);
}
return TRUE;
}
void
nle_operation_hard_cleanup (NleOperation * operation)
{
gboolean done = FALSE;
GValue item = { 0, };
GstIterator *pads;
GST_INFO_OBJECT (operation, "Hard reset of the operation");
pads = gst_element_iterate_sink_pads (GST_ELEMENT (operation));
while (!done) {
switch (gst_iterator_next (pads, &item)) {
case GST_ITERATOR_OK:
{
GstPad *sinkpad = g_value_get_object (&item);
GstPad *srcpad = gst_pad_get_peer (sinkpad);
if (srcpad) {
GST_ERROR ("Unlinking %" GST_PTR_FORMAT " and %"
GST_PTR_FORMAT, srcpad, sinkpad);
gst_pad_unlink (srcpad, sinkpad);
gst_object_unref (srcpad);
}
g_value_reset (&item);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (pads);
break;
default:
/* ERROR and DONE */
done = TRUE;
break;
}
}
nle_object_cleanup (NLE_OBJECT (operation));
gst_iterator_free (pads);
}
static GstPad *
nle_operation_request_new_pad (GstElement * element, GstPadTemplate * templ,
const gchar * name, const GstCaps * caps)
{
NleOperation *operation = (NleOperation *) element;
GstPad *ret;
GST_DEBUG ("template:%s name:%s", templ->name_template, name);
if (operation->num_sinks == operation->realsinks) {
GST_WARNING_OBJECT (element,
"We already have the maximum number of pads : %d",
operation->num_sinks);
return NULL;
}
ret = add_sink_pad ((NleOperation *) element);
return ret;
}
static void
nle_operation_release_pad (GstElement * element, GstPad * pad)
{
GST_DEBUG ("pad %s:%s", GST_DEBUG_PAD_NAME (pad));
remove_sink_pad ((NleOperation *) element, pad);
}
void
nle_operation_signal_input_priority_changed (NleOperation * operation,
GstPad * pad, guint32 priority)
{
GST_DEBUG_OBJECT (operation, "pad:%s:%s, priority:%d",
GST_DEBUG_PAD_NAME (pad), priority);
g_signal_emit (operation, nle_operation_signals[INPUT_PRIORITY_CHANGED],
0, pad, priority);
}