/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2005 Andy Wingo <wingo@pobox.com>
* 2006 Edward Hervey <bilboed@bilboed.com>
*
* gstghostpad.c: Proxy pads
*
* 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.
*/
/**
* SECTION:gstghostpad
* @title: GstGhostPad
* @short_description: Pseudo link pads
* @see_also: #GstPad
*
* GhostPads are useful when organizing pipelines with #GstBin like elements.
* The idea here is to create hierarchical element graphs. The bin element
* contains a sub-graph. Now one would like to treat the bin-element like any
* other #GstElement. This is where GhostPads come into play. A GhostPad acts as
* a proxy for another pad. Thus the bin can have sink and source ghost-pads
* that are associated with sink and source pads of the child elements.
*
* If the target pad is known at creation time, gst_ghost_pad_new() is the
* function to use to get a ghost-pad. Otherwise one can use gst_ghost_pad_new_no_target()
* to create the ghost-pad and use gst_ghost_pad_set_target() to establish the
* association later on.
*
* Note that GhostPads add overhead to the data processing of a pipeline.
*/
#include "gst_private.h"
#include "gstinfo.h"
#include "gstghostpad.h"
#include "gst.h"
#define GST_CAT_DEFAULT GST_CAT_PADS
#define GST_PROXY_PAD_CAST(obj) ((GstProxyPad *)obj)
#define GST_PROXY_PAD_PRIVATE(obj) (GST_PROXY_PAD_CAST (obj)->priv)
#define GST_PROXY_PAD_TARGET(pad) (GST_PAD_PEER (GST_PROXY_PAD_INTERNAL (pad)))
#define GST_PROXY_PAD_INTERNAL(pad) (GST_PROXY_PAD_PRIVATE (pad)->internal)
#define GST_PROXY_PAD_ACQUIRE_INTERNAL(pad, internal, retval) \
internal = \
GST_PAD_CAST (gst_proxy_pad_get_internal (GST_PROXY_PAD_CAST (pad))); \
if (internal == NULL) \
return retval;
#define GST_PROXY_PAD_RELEASE_INTERNAL(internal) gst_object_unref (internal);
struct _GstProxyPadPrivate
{
GstPad *internal;
};
G_DEFINE_TYPE (GstProxyPad, gst_proxy_pad, GST_TYPE_PAD);
static GstPad *gst_proxy_pad_get_target (GstPad * pad);
/**
* gst_proxy_pad_iterate_internal_links_default:
* @pad: the #GstPad to get the internal links of.
* @parent: (allow-none): the parent of @pad or %NULL
*
* Invoke the default iterate internal links function of the proxy pad.
*
* Returns: (nullable): a #GstIterator of #GstPad, or %NULL if @pad
* has no parent. Unref each returned pad with gst_object_unref().
*/
GstIterator *
gst_proxy_pad_iterate_internal_links_default (GstPad * pad, GstObject * parent)
{
GstIterator *res = NULL;
GstPad *internal;
GValue v = { 0, };
g_return_val_if_fail (GST_IS_PROXY_PAD (pad), NULL);
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, internal, NULL);
g_value_init (&v, GST_TYPE_PAD);
g_value_take_object (&v, internal);
res = gst_iterator_new_single (GST_TYPE_PAD, &v);
g_value_unset (&v);
return res;
}
/**
* gst_proxy_pad_chain_default:
* @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
* @parent: (allow-none): the parent of @pad or %NULL
* @buffer: (transfer full): the #GstBuffer to send, return GST_FLOW_ERROR
* if not.
*
* Invoke the default chain function of the proxy pad.
*
* Returns: a #GstFlowReturn from the pad.
*/
GstFlowReturn
gst_proxy_pad_chain_default (GstPad * pad, GstObject * parent,
GstBuffer * buffer)
{
GstFlowReturn res;
GstPad *internal;
g_return_val_if_fail (GST_IS_PROXY_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, internal, GST_FLOW_NOT_LINKED);
res = gst_pad_push (internal, buffer);
GST_PROXY_PAD_RELEASE_INTERNAL (internal);
return res;
}
/**
* gst_proxy_pad_chain_list_default:
* @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
* @parent: (allow-none): the parent of @pad or %NULL
* @list: (transfer full): the #GstBufferList to send, return GST_FLOW_ERROR
* if not.
*
* Invoke the default chain list function of the proxy pad.
*
* Returns: a #GstFlowReturn from the pad.
*/
GstFlowReturn
gst_proxy_pad_chain_list_default (GstPad * pad, GstObject * parent,
GstBufferList * list)
{
GstFlowReturn res;
GstPad *internal;
g_return_val_if_fail (GST_IS_PROXY_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_BUFFER_LIST (list), GST_FLOW_ERROR);
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, internal, GST_FLOW_NOT_LINKED);
res = gst_pad_push_list (internal, list);
GST_PROXY_PAD_RELEASE_INTERNAL (internal);
return res;
}
/**
* gst_proxy_pad_getrange_default:
* @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
* @parent: the parent of @pad
* @offset: The start offset of the buffer
* @size: The length of the buffer
* @buffer: (out callee-allocates): a pointer to hold the #GstBuffer,
* returns #GST_FLOW_ERROR if %NULL.
*
* Invoke the default getrange function of the proxy pad.
*
* Returns: a #GstFlowReturn from the pad.
*/
GstFlowReturn
gst_proxy_pad_getrange_default (GstPad * pad, GstObject * parent,
guint64 offset, guint size, GstBuffer ** buffer)
{
GstFlowReturn res;
GstPad *internal;
g_return_val_if_fail (GST_IS_PROXY_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, internal, GST_FLOW_NOT_LINKED);
res = gst_pad_pull_range (internal, offset, size, buffer);
GST_PROXY_PAD_RELEASE_INTERNAL (internal);
return res;
}
static GstPad *
gst_proxy_pad_get_target (GstPad * pad)
{
GstPad *target;
GST_OBJECT_LOCK (pad);
target = gst_pad_get_peer (GST_PROXY_PAD_INTERNAL (pad));
GST_OBJECT_UNLOCK (pad);
return target;
}
/**
* gst_proxy_pad_get_internal:
* @pad: the #GstProxyPad
*
* Get the internal pad of @pad. Unref target pad after usage.
*
* The internal pad of a #GstGhostPad is the internally used
* pad of opposite direction, which is used to link to the target.
*
* Returns: (transfer full) (nullable): the target #GstProxyPad, can
* be %NULL. Unref target pad after usage.
*/
GstProxyPad *
gst_proxy_pad_get_internal (GstProxyPad * pad)
{
GstPad *internal;
g_return_val_if_fail (GST_IS_PROXY_PAD (pad), NULL);
GST_OBJECT_LOCK (pad);
internal = GST_PROXY_PAD_INTERNAL (pad);
if (internal)
gst_object_ref (internal);
GST_OBJECT_UNLOCK (pad);
return GST_PROXY_PAD_CAST (internal);
}
static void
gst_proxy_pad_class_init (GstProxyPadClass * klass)
{
g_type_class_add_private (klass, sizeof (GstProxyPadPrivate));
/* Register common function pointer descriptions */
GST_DEBUG_REGISTER_FUNCPTR (gst_proxy_pad_iterate_internal_links_default);
GST_DEBUG_REGISTER_FUNCPTR (gst_proxy_pad_chain_default);
GST_DEBUG_REGISTER_FUNCPTR (gst_proxy_pad_chain_list_default);
GST_DEBUG_REGISTER_FUNCPTR (gst_proxy_pad_getrange_default);
}
static void
gst_proxy_pad_init (GstProxyPad * ppad)
{
GstPad *pad = (GstPad *) ppad;
GST_PROXY_PAD_PRIVATE (ppad) = G_TYPE_INSTANCE_GET_PRIVATE (ppad,
GST_TYPE_PROXY_PAD, GstProxyPadPrivate);
gst_pad_set_iterate_internal_links_function (pad,
gst_proxy_pad_iterate_internal_links_default);
GST_PAD_SET_PROXY_CAPS (pad);
GST_PAD_SET_PROXY_SCHEDULING (pad);
GST_PAD_SET_PROXY_ALLOCATION (pad);
}
/***********************************************************************
* Ghost pads, implemented as a pair of proxy pads (sort of)
*/
#define GST_GHOST_PAD_PRIVATE(obj) (GST_GHOST_PAD_CAST (obj)->priv)
struct _GstGhostPadPrivate
{
/* with PROXY_LOCK */
gboolean constructed;
};
G_DEFINE_TYPE (GstGhostPad, gst_ghost_pad, GST_TYPE_PROXY_PAD);
static void gst_ghost_pad_dispose (GObject * object);
static gboolean
gst_ghost_pad_internal_activate_push_default (GstPad * pad, GstObject * parent,
gboolean active)
{
gboolean ret;
GstPad *other;
GST_LOG_OBJECT (pad, "%sactivate push on %s:%s, we're ok",
(active ? "" : "de"), GST_DEBUG_PAD_NAME (pad));
/* in both cases (SRC and SINK) we activate just the internal pad. The targets
* will be activated later (or already in case of a ghost sinkpad). */
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, other, FALSE);
ret = gst_pad_activate_mode (other, GST_PAD_MODE_PUSH, active);
GST_PROXY_PAD_RELEASE_INTERNAL (other);
return ret;
}
static gboolean
gst_ghost_pad_internal_activate_pull_default (GstPad * pad, GstObject * parent,
gboolean active)
{
gboolean ret;
GstPad *other;
GST_LOG_OBJECT (pad, "%sactivate pull on %s:%s", (active ? "" : "de"),
GST_DEBUG_PAD_NAME (pad));
if (GST_PAD_DIRECTION (pad) == GST_PAD_SRC) {
/* we are activated in pull mode by our peer element, which is a sinkpad
* that wants to operate in pull mode. This activation has to propagate
* upstream through the pipeline. We call the internal activation function,
* which will trigger gst_ghost_pad_activate_pull_default, which propagates even
* further upstream */
GST_LOG_OBJECT (pad, "pad is src, activate internal");
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, other, FALSE);
ret = gst_pad_activate_mode (other, GST_PAD_MODE_PULL, active);
GST_PROXY_PAD_RELEASE_INTERNAL (other);
} else if (G_LIKELY ((other = gst_pad_get_peer (pad)))) {
/* We are SINK, the ghostpad is SRC, we propagate the activation upstream
* since we hold a pointer to the upstream peer. */
GST_LOG_OBJECT (pad, "activating peer");
ret = gst_pad_activate_mode (other, GST_PAD_MODE_PULL, active);
gst_object_unref (other);
} else if (active) {
/* this is failure, we can't activate pull if there is no peer */
GST_LOG_OBJECT (pad, "not src and no peer, failing");
ret = FALSE;
} else {
GST_LOG_OBJECT (pad, "deactivating pull, with no peer - allowing");
ret = TRUE;
}
return ret;
}
/**
* gst_ghost_pad_internal_activate_mode_default:
* @pad: the #GstPad to activate or deactivate.
* @parent: (allow-none): the parent of @pad or %NULL
* @mode: the requested activation mode
* @active: whether the pad should be active or not.
*
* Invoke the default activate mode function of a proxy pad that is
* owned by a ghost pad.
*
* Returns: %TRUE if the operation was successful.
*/
gboolean
gst_ghost_pad_internal_activate_mode_default (GstPad * pad, GstObject * parent,
GstPadMode mode, gboolean active)
{
gboolean res;
g_return_val_if_fail (GST_IS_PROXY_PAD (pad), FALSE);
switch (mode) {
case GST_PAD_MODE_PULL:
res = gst_ghost_pad_internal_activate_pull_default (pad, parent, active);
break;
case GST_PAD_MODE_PUSH:
res = gst_ghost_pad_internal_activate_push_default (pad, parent, active);
break;
default:
GST_LOG_OBJECT (pad, "unknown activation mode %d", mode);
res = FALSE;
break;
}
return res;
}
static gboolean
gst_ghost_pad_activate_push_default (GstPad * pad, GstObject * parent,
gboolean active)
{
gboolean ret;
GstPad *other;
g_return_val_if_fail (GST_IS_GHOST_PAD (pad), FALSE);
GST_LOG_OBJECT (pad, "%sactivate push on %s:%s, proxy internal",
(active ? "" : "de"), GST_DEBUG_PAD_NAME (pad));
/* just activate the internal pad */
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, other, FALSE);
ret = gst_pad_activate_mode (other, GST_PAD_MODE_PUSH, active);
GST_PROXY_PAD_RELEASE_INTERNAL (other);
return ret;
}
static gboolean
gst_ghost_pad_activate_pull_default (GstPad * pad, GstObject * parent,
gboolean active)
{
gboolean ret;
GstPad *other;
GST_LOG_OBJECT (pad, "%sactivate pull on %s:%s", (active ? "" : "de"),
GST_DEBUG_PAD_NAME (pad));
if (GST_PAD_DIRECTION (pad) == GST_PAD_SRC) {
/* the ghostpad is SRC and activated in pull mode by its peer, call the
* activation function of the internal pad to propagate the activation
* upstream */
GST_LOG_OBJECT (pad, "pad is src, activate internal");
GST_PROXY_PAD_ACQUIRE_INTERNAL (pad, other, FALSE);
ret = gst_pad_activate_mode (other, GST_PAD_MODE_PULL, active);
GST_PROXY_PAD_RELEASE_INTERNAL (other);
} else if (G_LIKELY ((other = gst_pad_get_peer (pad)))) {
/* We are SINK and activated by the internal pad, propagate activation
* upstream because we hold a ref to the upstream peer */
GST_LOG_OBJECT (pad, "activating peer");
ret = gst_pad_activate_mode (other, GST_PAD_MODE_PULL, active);
gst_object_unref (other);
} else if (active) {
/* this is failure, we can't activate pull if there is no peer */
GST_LOG_OBJECT (pad, "not src and no peer, failing");
ret = FALSE;
} else {
GST_LOG_OBJECT (pad, "deactivating pull, with no peer - allowing");
ret = TRUE;
}
return ret;
}
/**
* gst_ghost_pad_activate_mode_default:
* @pad: the #GstPad to activate or deactivate.
* @parent: (allow-none): the parent of @pad or %NULL
* @mode: the requested activation mode
* @active: whether the pad should be active or not.
*
* Invoke the default activate mode function of a ghost pad.
*
* Returns: %TRUE if the operation was successful.
*/
gboolean
gst_ghost_pad_activate_mode_default (GstPad * pad, GstObject * parent,
GstPadMode mode, gboolean active)
{
gboolean res;
g_return_val_if_fail (GST_IS_GHOST_PAD (pad), FALSE);
switch (mode) {
case GST_PAD_MODE_PULL:
res = gst_ghost_pad_activate_pull_default (pad, parent, active);
break;
case GST_PAD_MODE_PUSH:
res = gst_ghost_pad_activate_push_default (pad, parent, active);
break;
default:
GST_LOG_OBJECT (pad, "unknown activation mode %d", mode);
res = FALSE;
break;
}
return res;
}
static void
gst_ghost_pad_class_init (GstGhostPadClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
g_type_class_add_private (klass, sizeof (GstGhostPadPrivate));
gobject_class->dispose = gst_ghost_pad_dispose;
GST_DEBUG_REGISTER_FUNCPTR (gst_ghost_pad_activate_pull_default);
GST_DEBUG_REGISTER_FUNCPTR (gst_ghost_pad_activate_push_default);
}
static void
gst_ghost_pad_init (GstGhostPad * pad)
{
GST_GHOST_PAD_PRIVATE (pad) = G_TYPE_INSTANCE_GET_PRIVATE (pad,
GST_TYPE_GHOST_PAD, GstGhostPadPrivate);
gst_pad_set_activatemode_function (GST_PAD_CAST (pad),
gst_ghost_pad_activate_mode_default);
}
static void
gst_ghost_pad_dispose (GObject * object)
{
GstPad *pad;
GstPad *internal;
GstPad *peer;
pad = GST_PAD (object);
GST_DEBUG_OBJECT (pad, "dispose");
gst_ghost_pad_set_target (GST_GHOST_PAD (pad), NULL);
/* Unlink here so that gst_pad_dispose doesn't. That would lead to a call to
* gst_ghost_pad_unlink_default when the ghost pad is in an inconsistent state */
peer = gst_pad_get_peer (pad);
if (peer) {
if (GST_PAD_IS_SRC (pad))
gst_pad_unlink (pad, peer);
else
gst_pad_unlink (peer, pad);
gst_object_unref (peer);
}
GST_OBJECT_LOCK (pad);
internal = GST_PROXY_PAD_INTERNAL (pad);
if (internal) {
gst_pad_set_activatemode_function (internal, NULL);
GST_PROXY_PAD_INTERNAL (pad) = NULL;
GST_PROXY_PAD_INTERNAL (internal) = NULL;
/* disposes of the internal pad, since the ghostpad is the only possible object
* that has a refcount on the internal pad. */
gst_object_unparent (GST_OBJECT_CAST (internal));
}
GST_OBJECT_UNLOCK (pad);
G_OBJECT_CLASS (gst_ghost_pad_parent_class)->dispose (object);
}
/**
* gst_ghost_pad_construct:
* @gpad: the newly allocated ghost pad
*
* Finish initialization of a newly allocated ghost pad.
*
* This function is most useful in language bindings and when subclassing
* #GstGhostPad; plugin and application developers normally will not call this
* function. Call this function directly after a call to g_object_new
* (GST_TYPE_GHOST_PAD, "direction", @dir, ..., NULL).
*
* Returns: %TRUE if the construction succeeds, %FALSE otherwise.
*/
gboolean
gst_ghost_pad_construct (GstGhostPad * gpad)
{
GstPadDirection dir, otherdir;
GstPadTemplate *templ;
GstPad *pad, *internal;
g_return_val_if_fail (GST_IS_GHOST_PAD (gpad), FALSE);
g_return_val_if_fail (!GST_GHOST_PAD_PRIVATE (gpad)->constructed, FALSE);
g_object_get (gpad, "direction", &dir, "template", &templ, NULL);
g_return_val_if_fail (dir != GST_PAD_UNKNOWN, FALSE);
pad = GST_PAD (gpad);
/* Set directional padfunctions for ghostpad */
if (dir == GST_PAD_SINK) {
gst_pad_set_chain_function (pad, gst_proxy_pad_chain_default);
gst_pad_set_chain_list_function (pad, gst_proxy_pad_chain_list_default);
} else {
gst_pad_set_getrange_function (pad, gst_proxy_pad_getrange_default);
}
/* INTERNAL PAD, it always exists and is child of the ghostpad */
otherdir = (dir == GST_PAD_SRC) ? GST_PAD_SINK : GST_PAD_SRC;
if (templ) {
internal =
g_object_new (GST_TYPE_PROXY_PAD, "name", NULL,
"direction", otherdir, "template", templ, NULL);
/* release ref obtained via g_object_get */
gst_object_unref (templ);
} else {
internal =
g_object_new (GST_TYPE_PROXY_PAD, "name", NULL,
"direction", otherdir, NULL);
}
GST_PAD_UNSET_FLUSHING (internal);
/* Set directional padfunctions for internal pad */
if (dir == GST_PAD_SRC) {
gst_pad_set_chain_function (internal, gst_proxy_pad_chain_default);
gst_pad_set_chain_list_function (internal,
gst_proxy_pad_chain_list_default);
} else {
gst_pad_set_getrange_function (internal, gst_proxy_pad_getrange_default);
}
GST_OBJECT_LOCK (pad);
/* now make the ghostpad a parent of the internal pad */
if (!gst_object_set_parent (GST_OBJECT_CAST (internal),
GST_OBJECT_CAST (pad)))
goto parent_failed;
/* The ghostpad is the parent of the internal pad and is the only object that
* can have a refcount on the internal pad.
* At this point, the GstGhostPad has a refcount of 1, and the internal pad has
* a refcount of 1.
* When the refcount of the GstGhostPad drops to 0, the ghostpad will dispose
* its refcount on the internal pad in the dispose method by un-parenting it.
* This is why we don't take extra refcounts in the assignments below
*/
GST_PROXY_PAD_INTERNAL (pad) = internal;
GST_PROXY_PAD_INTERNAL (internal) = pad;
/* special activation functions for the internal pad */
gst_pad_set_activatemode_function (internal,
gst_ghost_pad_internal_activate_mode_default);
GST_OBJECT_UNLOCK (pad);
GST_GHOST_PAD_PRIVATE (gpad)->constructed = TRUE;
return TRUE;
/* ERRORS */
parent_failed:
{
GST_WARNING_OBJECT (gpad, "Could not set internal pad %s:%s",
GST_DEBUG_PAD_NAME (internal));
g_critical ("Could not set internal pad %s:%s",
GST_DEBUG_PAD_NAME (internal));
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
static GstPad *
gst_ghost_pad_new_full (const gchar * name, GstPadDirection dir,
GstPadTemplate * templ)
{
GstGhostPad *ret;
g_return_val_if_fail (dir != GST_PAD_UNKNOWN, NULL);
/* OBJECT CREATION */
if (templ) {
GType pad_type =
GST_PAD_TEMPLATE_GTYPE (templ) ==
G_TYPE_NONE ? GST_TYPE_GHOST_PAD : GST_PAD_TEMPLATE_GTYPE (templ);
g_return_val_if_fail (g_type_is_a (pad_type, GST_TYPE_GHOST_PAD), NULL);
ret = g_object_new (pad_type, "name", name,
"direction", dir, "template", templ, NULL);
} else {
ret = g_object_new (GST_TYPE_GHOST_PAD, "name", name,
"direction", dir, NULL);
}
if (!gst_ghost_pad_construct (ret))
goto construct_failed;
return GST_PAD_CAST (ret);
construct_failed:
/* already logged */
gst_object_unref (ret);
return NULL;
}
/**
* gst_ghost_pad_new_no_target:
* @name: (allow-none): the name of the new pad, or %NULL to assign a default name.
* @dir: the direction of the ghostpad
*
* Create a new ghostpad without a target with the given direction.
* A target can be set on the ghostpad later with the
* gst_ghost_pad_set_target() function.
*
* The created ghostpad will not have a padtemplate.
*
* Returns: (transfer floating) (nullable): a new #GstPad, or %NULL in
* case of an error.
*/
GstPad *
gst_ghost_pad_new_no_target (const gchar * name, GstPadDirection dir)
{
GstPad *ret;
g_return_val_if_fail (dir != GST_PAD_UNKNOWN, NULL);
GST_LOG ("name:%s, direction:%d", GST_STR_NULL (name), dir);
ret = gst_ghost_pad_new_full (name, dir, NULL);
return ret;
}
/**
* gst_ghost_pad_new:
* @name: (allow-none): the name of the new pad, or %NULL to assign a default name
* @target: (transfer none): the pad to ghost.
*
* Create a new ghostpad with @target as the target. The direction will be taken
* from the target pad. @target must be unlinked.
*
* Will ref the target.
*
* Returns: (transfer floating) (nullable): a new #GstPad, or %NULL in
* case of an error.
*/
GstPad *
gst_ghost_pad_new (const gchar * name, GstPad * target)
{
GstPad *ret;
g_return_val_if_fail (GST_IS_PAD (target), NULL);
g_return_val_if_fail (!gst_pad_is_linked (target), NULL);
GST_LOG ("name:%s, target:%s:%s", GST_STR_NULL (name),
GST_DEBUG_PAD_NAME (target));
if ((ret = gst_ghost_pad_new_no_target (name, GST_PAD_DIRECTION (target))))
if (!gst_ghost_pad_set_target (GST_GHOST_PAD_CAST (ret), target))
goto set_target_failed;
return ret;
/* ERRORS */
set_target_failed:
{
GST_WARNING_OBJECT (ret, "failed to set target %s:%s",
GST_DEBUG_PAD_NAME (target));
gst_object_unref (ret);
return NULL;
}
}
/**
* gst_ghost_pad_new_from_template:
* @name: (allow-none): the name of the new pad, or %NULL to assign a default name.
* @target: (transfer none): the pad to ghost.
* @templ: (transfer none): the #GstPadTemplate to use on the ghostpad.
*
* Create a new ghostpad with @target as the target. The direction will be taken
* from the target pad. The template used on the ghostpad will be @template.
*
* Will ref the target.
*
* Returns: (transfer floating) (nullable): a new #GstPad, or %NULL in
* case of an error.
*/
GstPad *
gst_ghost_pad_new_from_template (const gchar * name, GstPad * target,
GstPadTemplate * templ)
{
GstPad *ret;
g_return_val_if_fail (GST_IS_PAD (target), NULL);
g_return_val_if_fail (!gst_pad_is_linked (target), NULL);
g_return_val_if_fail (templ != NULL, NULL);
g_return_val_if_fail (GST_PAD_TEMPLATE_DIRECTION (templ) ==
GST_PAD_DIRECTION (target), NULL);
GST_LOG ("name:%s, target:%s:%s, templ:%p", GST_STR_NULL (name),
GST_DEBUG_PAD_NAME (target), templ);
if ((ret = gst_ghost_pad_new_full (name, GST_PAD_DIRECTION (target), templ)))
if (!gst_ghost_pad_set_target (GST_GHOST_PAD_CAST (ret), target))
goto set_target_failed;
return ret;
/* ERRORS */
set_target_failed:
{
GST_WARNING_OBJECT (ret, "failed to set target %s:%s",
GST_DEBUG_PAD_NAME (target));
gst_object_unref (ret);
return NULL;
}
}
/**
* gst_ghost_pad_new_no_target_from_template:
* @name: (allow-none): the name of the new pad, or %NULL to assign a default name
* @templ: (transfer none): the #GstPadTemplate to create the ghostpad from.
*
* Create a new ghostpad based on @templ, without setting a target. The
* direction will be taken from the @templ.
*
* Returns: (transfer floating) (nullable): a new #GstPad, or %NULL in
* case of an error.
*/
GstPad *
gst_ghost_pad_new_no_target_from_template (const gchar * name,
GstPadTemplate * templ)
{
GstPad *ret;
g_return_val_if_fail (templ != NULL, NULL);
ret =
gst_ghost_pad_new_full (name, GST_PAD_TEMPLATE_DIRECTION (templ), templ);
return ret;
}
/**
* gst_ghost_pad_get_target:
* @gpad: the #GstGhostPad
*
* Get the target pad of @gpad. Unref target pad after usage.
*
* Returns: (transfer full) (nullable): the target #GstPad, can be
* %NULL if the ghostpad has no target set. Unref target pad after
* usage.
*/
GstPad *
gst_ghost_pad_get_target (GstGhostPad * gpad)
{
GstPad *ret;
g_return_val_if_fail (GST_IS_GHOST_PAD (gpad), NULL);
ret = gst_proxy_pad_get_target (GST_PAD_CAST (gpad));
GST_DEBUG_OBJECT (gpad, "get target %s:%s", GST_DEBUG_PAD_NAME (ret));
return ret;
}
/**
* gst_ghost_pad_set_target:
* @gpad: the #GstGhostPad
* @newtarget: (transfer none) (allow-none): the new pad target
*
* Set the new target of the ghostpad @gpad. Any existing target
* is unlinked and links to the new target are established. if @newtarget is
* %NULL the target will be cleared.
*
* Returns: %TRUE if the new target could be set. This function
* can return %FALSE when the internal pads could not be linked.
*/
gboolean
gst_ghost_pad_set_target (GstGhostPad * gpad, GstPad * newtarget)
{
GstPad *internal;
GstPad *oldtarget;
GstPadLinkReturn lret;
g_return_val_if_fail (GST_IS_GHOST_PAD (gpad), FALSE);
g_return_val_if_fail (GST_PAD_CAST (gpad) != newtarget, FALSE);
GST_OBJECT_LOCK (gpad);
internal = GST_PROXY_PAD_INTERNAL (gpad);
if (newtarget == internal) {
GST_OBJECT_UNLOCK (gpad);
GST_WARNING_OBJECT (gpad, "Target has already been set to %s:%s",
GST_DEBUG_PAD_NAME (newtarget));
return TRUE;
}
if (newtarget)
GST_DEBUG_OBJECT (gpad, "set target %s:%s", GST_DEBUG_PAD_NAME (newtarget));
else
GST_DEBUG_OBJECT (gpad, "clearing target");
/* clear old target */
if ((oldtarget = gst_pad_get_peer (internal))) {
GST_OBJECT_UNLOCK (gpad);
/* unlink internal pad */
if (GST_PAD_IS_SRC (internal))
gst_pad_unlink (internal, oldtarget);
else
gst_pad_unlink (oldtarget, internal);
gst_object_unref (oldtarget);
} else {
GST_OBJECT_UNLOCK (gpad);
}
if (newtarget) {
/* and link to internal pad without any checks */
GST_DEBUG_OBJECT (gpad, "connecting internal pad to target %"
GST_PTR_FORMAT, newtarget);
if (GST_PAD_IS_SRC (internal))
lret =
gst_pad_link_full (internal, newtarget, GST_PAD_LINK_CHECK_NOTHING);
else
lret =
gst_pad_link_full (newtarget, internal, GST_PAD_LINK_CHECK_NOTHING);
if (lret != GST_PAD_LINK_OK)
goto link_failed;
}
return TRUE;
/* ERRORS */
link_failed:
{
GST_WARNING_OBJECT (gpad, "could not link internal and target, reason:%s",
gst_pad_link_get_name (lret));
return FALSE;
}
}