gstreamer/gst/gstghostpad.c
Tim-Philipp Müller 5dc534c642 docs: it's its
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2009-08-31 17:00:17 +01:00

1230 lines
34 KiB
C

/* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION: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 other
* #GstElements. 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.
*
* Last reviewed on 2005-11-18 (0.9.5)
*/
#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_PROXY_PAD_PRIVATE (pad)->target)
#define GST_PROXY_PAD_INTERNAL(pad) (GST_PROXY_PAD_PRIVATE (pad)->internal)
#define GST_PROXY_PAD_RETARGET(pad) (GST_PROXY_PAD_PRIVATE (pad)->retarget)
#define GST_PROXY_GET_LOCK(pad) (GST_PROXY_PAD_PRIVATE (pad)->proxy_lock)
#define GST_PROXY_LOCK(pad) (g_mutex_lock (GST_PROXY_GET_LOCK (pad)))
#define GST_PROXY_UNLOCK(pad) (g_mutex_unlock (GST_PROXY_GET_LOCK (pad)))
struct _GstProxyPadPrivate
{
/* with PROXY_LOCK */
GMutex *proxy_lock;
GstPad *target;
GstPad *internal;
gboolean retarget;
};
G_DEFINE_TYPE (GstProxyPad, gst_proxy_pad, GST_TYPE_PAD);
static GstPad *gst_proxy_pad_get_target (GstPad * pad);
static void gst_proxy_pad_dispose (GObject * object);
static void gst_proxy_pad_finalize (GObject * object);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_proxy_pad_save_thyself (GstObject * object,
xmlNodePtr parent);
#endif
static void on_src_target_notify (GstPad * target,
GParamSpec * unused, gpointer user_data);
static void
gst_proxy_pad_class_init (GstProxyPadClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
g_type_class_add_private (klass, sizeof (GstProxyPadPrivate));
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_proxy_pad_dispose);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_proxy_pad_finalize);
#ifndef GST_DISABLE_LOADSAVE
{
GstObjectClass *gstobject_class = (GstObjectClass *) klass;
gstobject_class->save_thyself =
GST_DEBUG_FUNCPTR (gst_proxy_pad_save_thyself);
}
#endif
}
static const GstQueryType *
gst_proxy_pad_do_query_type (GstPad * pad)
{
GstPad *target = gst_proxy_pad_get_target (pad);
const GstQueryType *res = NULL;
if (target) {
res = gst_pad_get_query_types (target);
gst_object_unref (target);
}
return res;
}
static gboolean
gst_proxy_pad_do_event (GstPad * pad, GstEvent * event)
{
gboolean res = FALSE;
GstPad *internal = GST_PROXY_PAD_INTERNAL (pad);
res = gst_pad_push_event (internal, event);
return res;
}
static gboolean
gst_proxy_pad_do_query (GstPad * pad, GstQuery * query)
{
gboolean res = FALSE;
GstPad *target = gst_proxy_pad_get_target (pad);
if (target) {
res = gst_pad_query (target, query);
gst_object_unref (target);
}
return res;
}
static GstIterator *
gst_proxy_pad_do_iterate_internal_links (GstPad * pad)
{
GstIterator *res = NULL;
GstPad *target = gst_proxy_pad_get_target (pad);
if (target) {
res = gst_pad_iterate_internal_links (target);
gst_object_unref (target);
}
return res;
}
static GstFlowReturn
gst_proxy_pad_do_bufferalloc (GstPad * pad, guint64 offset, guint size,
GstCaps * caps, GstBuffer ** buf)
{
GstFlowReturn result;
GstPad *internal = GST_PROXY_PAD_INTERNAL (pad);
result = gst_pad_alloc_buffer (internal, offset, size, caps, buf);
return result;
}
static GstFlowReturn
gst_proxy_pad_do_chain (GstPad * pad, GstBuffer * buffer)
{
GstFlowReturn res;
GstPad *internal = GST_PROXY_PAD_INTERNAL (pad);
res = gst_pad_push (internal, buffer);
return res;
}
static GstFlowReturn
gst_proxy_pad_do_chain_list (GstPad * pad, GstBufferList * list)
{
GstFlowReturn res;
GstPad *internal = GST_PROXY_PAD_INTERNAL (pad);
res = gst_pad_push_list (internal, list);
return res;
}
static GstFlowReturn
gst_proxy_pad_do_getrange (GstPad * pad, guint64 offset, guint size,
GstBuffer ** buffer)
{
GstFlowReturn res;
GstPad *internal = GST_PROXY_PAD_INTERNAL (pad);
res = gst_pad_pull_range (internal, offset, size, buffer);
return res;
}
static gboolean
gst_proxy_pad_do_checkgetrange (GstPad * pad)
{
gboolean result;
GstPad *internal = GST_PROXY_PAD_INTERNAL (pad);
result = gst_pad_check_pull_range (internal);
return result;
}
static GstCaps *
gst_proxy_pad_do_getcaps (GstPad * pad)
{
GstPad *target = gst_proxy_pad_get_target (pad);
GstCaps *res;
GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
if (target) {
/* if we have a real target, proxy the call */
res = gst_pad_get_caps (target);
GST_DEBUG_OBJECT (pad, "get caps of target %s:%s : %" GST_PTR_FORMAT,
GST_DEBUG_PAD_NAME (target), res);
gst_object_unref (target);
/* filter against the template */
if (templ && res) {
GstCaps *filt, *tmp;
filt = GST_PAD_TEMPLATE_CAPS (templ);
if (filt) {
tmp = gst_caps_intersect (filt, res);
gst_caps_unref (res);
res = tmp;
GST_DEBUG_OBJECT (pad,
"filtered against template gives %" GST_PTR_FORMAT, res);
}
}
} else {
/* else, if we have a template, use its caps. */
if (templ) {
res = GST_PAD_TEMPLATE_CAPS (templ);
GST_DEBUG_OBJECT (pad,
"using pad template %p with caps %p %" GST_PTR_FORMAT, templ, res,
res);
res = gst_caps_ref (res);
goto done;
}
/* last resort, any caps */
GST_DEBUG_OBJECT (pad, "pad has no template, returning ANY");
res = gst_caps_new_any ();
}
done:
return res;
}
static gboolean
gst_proxy_pad_do_acceptcaps (GstPad * pad, GstCaps * caps)
{
GstPad *target = gst_proxy_pad_get_target (pad);
gboolean res;
if (target) {
res = gst_pad_accept_caps (target, caps);
gst_object_unref (target);
} else {
/* We don't have a target, we return TRUE and we assume that any future
* target will be able to deal with any configured caps. */
res = TRUE;
}
return res;
}
static void
gst_proxy_pad_do_fixatecaps (GstPad * pad, GstCaps * caps)
{
GstPad *target = gst_proxy_pad_get_target (pad);
if (target) {
gst_pad_fixate_caps (target, caps);
gst_object_unref (target);
}
}
static gboolean
gst_proxy_pad_do_setcaps (GstPad * pad, GstCaps * caps)
{
GstPad *target = gst_proxy_pad_get_target (pad);
gboolean res;
if (target) {
res = gst_pad_set_caps (target, caps);
gst_object_unref (target);
} else {
/* We don't have any target, but we shouldn't return FALSE since this
* would stop the actual push of a buffer (which might trigger a pad block
* or probe, or properly return GST_FLOW_NOT_LINKED.
*/
res = TRUE;
}
return res;
}
static gboolean
gst_proxy_pad_set_target_unlocked (GstPad * pad, GstPad * target)
{
GstPad *oldtarget;
if (target) {
GST_LOG_OBJECT (pad, "setting target %s:%s", GST_DEBUG_PAD_NAME (target));
if (G_UNLIKELY (GST_PAD_DIRECTION (pad) != GST_PAD_DIRECTION (target)))
goto wrong_direction;
} else
GST_LOG_OBJECT (pad, "clearing target");
/* clear old target */
if ((oldtarget = GST_PROXY_PAD_TARGET (pad)))
gst_object_unref (oldtarget);
/* set and ref new target if any */
if (target)
GST_PROXY_PAD_TARGET (pad) = gst_object_ref (target);
else
GST_PROXY_PAD_TARGET (pad) = NULL;
return TRUE;
/* ERRORS */
wrong_direction:
{
GST_ERROR_OBJECT (pad,
"target pad doesn't have the same direction as ourself");
return FALSE;
}
}
static gboolean
gst_proxy_pad_set_target (GstPad * pad, GstPad * target)
{
gboolean result;
GST_PROXY_LOCK (pad);
result = gst_proxy_pad_set_target_unlocked (pad, target);
GST_PROXY_UNLOCK (pad);
return result;
}
static GstPad *
gst_proxy_pad_get_target (GstPad * pad)
{
GstPad *target;
GST_PROXY_LOCK (pad);
target = GST_PROXY_PAD_TARGET (pad);
if (target)
gst_object_ref (target);
GST_PROXY_UNLOCK (pad);
return target;
}
static void
gst_proxy_pad_do_unlink (GstPad * pad)
{
GstPad *internal;
/* don't do anything if this unlink resulted from retargeting the pad
* controlled by the ghostpad. We only want to invalidate the target pad when
* the element suddently unlinked with our internal pad. */
if (GST_PROXY_PAD_RETARGET (pad))
return;
internal = GST_PROXY_PAD_INTERNAL (pad);
GST_DEBUG_OBJECT (pad, "pad is unlinked");
gst_proxy_pad_set_target (internal, NULL);
}
static void
gst_proxy_pad_dispose (GObject * object)
{
GstPad *pad = GST_PAD (object);
GstPad **target_p;
GST_PROXY_LOCK (pad);
/* remove and unref the target */
target_p = &GST_PROXY_PAD_TARGET (pad);
gst_object_replace ((GstObject **) target_p, NULL);
/* The internal is only cleared by GstGhostPad::dispose, since it is the
* parent of non-ghost GstProxyPad and owns the refcount on the internal.
*/
GST_PROXY_UNLOCK (pad);
G_OBJECT_CLASS (gst_proxy_pad_parent_class)->dispose (object);
}
static void
gst_proxy_pad_finalize (GObject * object)
{
GstProxyPad *pad = GST_PROXY_PAD (object);
g_mutex_free (GST_PROXY_GET_LOCK (pad));
GST_PROXY_GET_LOCK (pad) = NULL;
G_OBJECT_CLASS (gst_proxy_pad_parent_class)->finalize (object);
}
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_PROXY_GET_LOCK (pad) = g_mutex_new ();
gst_pad_set_query_type_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_query_type));
gst_pad_set_event_function (pad, GST_DEBUG_FUNCPTR (gst_proxy_pad_do_event));
gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_proxy_pad_do_query));
gst_pad_set_iterate_internal_links_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_iterate_internal_links));
gst_pad_set_getcaps_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_getcaps));
gst_pad_set_acceptcaps_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_acceptcaps));
gst_pad_set_fixatecaps_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_fixatecaps));
gst_pad_set_setcaps_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_setcaps));
gst_pad_set_unlink_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_unlink));
}
#ifndef GST_DISABLE_LOADSAVE
/**
* gst_proxy_pad_save_thyself:
* @pad: a ghost #GstPad to save.
* @parent: the parent #xmlNodePtr to save the description in.
*
* Saves the ghost pad into an xml representation.
*
* Returns: the #xmlNodePtr representation of the pad.
*/
static xmlNodePtr
gst_proxy_pad_save_thyself (GstObject * object, xmlNodePtr parent)
{
xmlNodePtr self;
GstProxyPad *proxypad;
GstPad *pad;
GstPad *peer;
g_return_val_if_fail (GST_IS_PROXY_PAD (object), NULL);
self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
xmlNewChild (self, NULL, (xmlChar *) "name",
(xmlChar *) GST_OBJECT_NAME (object));
xmlNewChild (self, NULL, (xmlChar *) "parent",
(xmlChar *) GST_OBJECT_NAME (GST_OBJECT_PARENT (object)));
proxypad = GST_PROXY_PAD_CAST (object);
pad = GST_PAD_CAST (proxypad);
peer = GST_PAD_CAST (pad->peer);
if (GST_IS_PAD (pad)) {
if (GST_PAD_IS_SRC (pad))
xmlNewChild (self, NULL, (xmlChar *) "direction", (xmlChar *) "source");
else if (GST_PAD_IS_SINK (pad))
xmlNewChild (self, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
else
xmlNewChild (self, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
} else {
xmlNewChild (self, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
}
if (GST_IS_PAD (peer)) {
gchar *content = g_strdup_printf ("%s.%s",
GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
xmlNewChild (self, NULL, (xmlChar *) "peer", (xmlChar *) content);
g_free (content);
} else {
xmlNewChild (self, NULL, (xmlChar *) "peer", NULL);
}
return self;
}
#endif /* GST_DISABLE_LOADSAVE */
/***********************************************************************
* 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 */
gulong notify_id;
gboolean constructed;
};
G_DEFINE_TYPE (GstGhostPad, gst_ghost_pad, GST_TYPE_PROXY_PAD);
static void gst_ghost_pad_dispose (GObject * object);
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_DEBUG_FUNCPTR (gst_ghost_pad_dispose);
}
/* see gstghostpad design docs */
static gboolean
gst_ghost_pad_internal_do_activate_push (GstPad * pad, 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). */
other = GST_PROXY_PAD_INTERNAL (pad);
ret = gst_pad_activate_push (other, active);
return ret;
}
static gboolean
gst_ghost_pad_internal_do_activate_pull (GstPad * pad, 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 throught the pipeline. We call the internal activation function,
* which will trigger gst_ghost_pad_do_activate_pull, which propagates even
* further upstream */
GST_LOG_OBJECT (pad, "pad is src, activate internal");
other = GST_PROXY_PAD_INTERNAL (pad);
ret = gst_pad_activate_pull (other, active);
} 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_pull (other, active);
gst_object_unref (other);
} else {
/* 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;
}
return ret;
}
static gboolean
gst_ghost_pad_do_activate_push (GstPad * pad, gboolean active)
{
gboolean ret;
GstPad *other;
GST_LOG_OBJECT (pad, "%sactivate push on %s:%s, proxy internal",
(active ? "" : "de"), GST_DEBUG_PAD_NAME (pad));
/* just activate the internal pad */
other = GST_PROXY_PAD_INTERNAL (pad);
ret = gst_pad_activate_push (other, active);
return ret;
}
static gboolean
gst_ghost_pad_do_activate_pull (GstPad * pad, 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");
other = GST_PROXY_PAD_INTERNAL (pad);
ret = gst_pad_activate_pull (other, active);
} 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_pull (other, active);
gst_object_unref (other);
} else {
/* no peer, we fail */
GST_LOG_OBJECT (pad, "pad not src and no peer, failing");
ret = FALSE;
}
return ret;
}
static GstPadLinkReturn
gst_ghost_pad_do_link (GstPad * pad, GstPad * peer)
{
GstPadLinkReturn ret;
GstPad *internal;
GST_DEBUG_OBJECT (pad, "linking ghostpad");
internal = GST_PROXY_PAD_INTERNAL (pad);
if (!gst_proxy_pad_set_target (internal, peer))
goto target_failed;
ret = GST_PAD_LINK_OK;
/* if we are a source pad, we should call the peer link function
* if the peer has one, see design docs. */
if (GST_PAD_IS_SRC (pad)) {
if (GST_PAD_LINKFUNC (peer)) {
ret = GST_PAD_LINKFUNC (peer) (peer, pad);
if (ret != GST_PAD_LINK_OK)
goto link_failed;
}
}
return ret;
/* ERRORS */
target_failed:
{
GST_DEBUG_OBJECT (pad, "setting target failed");
return GST_PAD_LINK_REFUSED;
}
link_failed:
{
GST_DEBUG_OBJECT (pad, "linking failed");
/* clear target again */
gst_proxy_pad_set_target (internal, NULL);
return ret;
}
}
static void
gst_ghost_pad_do_unlink (GstPad * pad)
{
GstPad *internal;
internal = GST_PROXY_PAD_INTERNAL (pad);
GST_DEBUG_OBJECT (pad, "unlinking ghostpad");
/* The target of the internal pad is no longer valid */
gst_proxy_pad_set_target (internal, NULL);
}
static void
on_int_notify (GstPad * internal, GParamSpec * unused, GstGhostPad * pad)
{
GstCaps *caps;
gboolean changed;
g_object_get (internal, "caps", &caps, NULL);
GST_DEBUG_OBJECT (pad, "notified %p %" GST_PTR_FORMAT, caps, caps);
GST_OBJECT_LOCK (pad);
changed = (GST_PAD_CAPS (pad) != caps);
if (changed)
gst_caps_replace (&(GST_PAD_CAPS (pad)), caps);
GST_OBJECT_UNLOCK (pad);
if (changed)
g_object_notify (G_OBJECT (pad), "caps");
if (caps)
gst_caps_unref (caps);
}
static void
on_src_target_notify (GstPad * target, GParamSpec * unused, gpointer user_data)
{
GstProxyPad *proxypad;
GstGhostPad *gpad;
GstCaps *caps;
gboolean changed;
g_object_get (target, "caps", &caps, NULL);
GST_OBJECT_LOCK (target);
/* First check if the peer is still available and our proxy pad */
if (!GST_PAD_PEER (target) || !GST_IS_PROXY_PAD (GST_PAD_PEER (target))) {
GST_OBJECT_UNLOCK (target);
gst_caps_unref (caps);
return;
}
proxypad = GST_PROXY_PAD (GST_PAD_PEER (target));
GST_PROXY_LOCK (proxypad);
/* Now check if the proxypad's internal pad is still there and
* a ghostpad */
if (!GST_PROXY_PAD_INTERNAL (proxypad) ||
!GST_IS_GHOST_PAD (GST_PROXY_PAD_INTERNAL (proxypad))) {
GST_OBJECT_UNLOCK (target);
GST_PROXY_UNLOCK (proxypad);
gst_caps_unref (caps);
return;
}
gpad = GST_GHOST_PAD (GST_PROXY_PAD_INTERNAL (proxypad));
g_object_ref (gpad);
GST_PROXY_UNLOCK (proxypad);
GST_OBJECT_UNLOCK (target);
GST_OBJECT_LOCK (gpad);
GST_DEBUG_OBJECT (gpad, "notified %p %" GST_PTR_FORMAT, caps, caps);
changed = (GST_PAD_CAPS (gpad) != caps);
if (changed)
gst_caps_replace (&(GST_PAD_CAPS (gpad)), caps);
GST_OBJECT_UNLOCK (gpad);
if (changed)
g_object_notify (G_OBJECT (gpad), "caps");
g_object_unref (gpad);
if (caps)
gst_caps_unref (caps);
}
static gboolean
gst_ghost_pad_do_setcaps (GstPad * pad, GstCaps * caps)
{
if (GST_PAD_DIRECTION (pad) == GST_PAD_SRC)
return TRUE;
return gst_proxy_pad_do_setcaps (pad, caps);
}
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_setcaps_function (GST_PAD_CAST (pad),
GST_DEBUG_FUNCPTR (gst_ghost_pad_do_setcaps));
gst_pad_set_activatepull_function (GST_PAD_CAST (pad),
GST_DEBUG_FUNCPTR (gst_ghost_pad_do_activate_pull));
gst_pad_set_activatepush_function (GST_PAD_CAST (pad),
GST_DEBUG_FUNCPTR (gst_ghost_pad_do_activate_push));
}
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_do_unlink 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_PROXY_LOCK (pad);
internal = GST_PROXY_PAD_INTERNAL (pad);
gst_pad_set_activatepull_function (internal, NULL);
gst_pad_set_activatepush_function (internal, NULL);
g_signal_handler_disconnect (internal,
GST_GHOST_PAD_PRIVATE (pad)->notify_id);
/* 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_PROXY_PAD_INTERNAL (pad) = NULL;
GST_PROXY_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.
*
* Since: 0.10.22
*/
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,
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_bufferalloc_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_bufferalloc));
gst_pad_set_chain_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_chain));
gst_pad_set_chain_list_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_chain_list));
} else {
gst_pad_set_getrange_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_getrange));
gst_pad_set_checkgetrange_function (pad,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_checkgetrange));
}
/* link/unlink functions */
gst_pad_set_link_function (pad, GST_DEBUG_FUNCPTR (gst_ghost_pad_do_link));
gst_pad_set_unlink_function (pad,
GST_DEBUG_FUNCPTR (gst_ghost_pad_do_unlink));
/* 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_bufferalloc_function (internal,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_bufferalloc));
gst_pad_set_chain_function (internal,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_chain));
gst_pad_set_chain_list_function (internal,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_chain_list));
} else {
gst_pad_set_getrange_function (internal,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_getrange));
gst_pad_set_checkgetrange_function (internal,
GST_DEBUG_FUNCPTR (gst_proxy_pad_do_checkgetrange));
}
GST_PROXY_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;
/* could be more general here, iterating over all writable properties...
* taking the short road for now tho */
GST_GHOST_PAD_PRIVATE (pad)->notify_id =
g_signal_connect (internal, "notify::caps", G_CALLBACK (on_int_notify),
pad);
/* call function to init values of the pad caps */
on_int_notify (internal, NULL, GST_GHOST_PAD_CAST (pad));
/* special activation functions for the internal pad */
gst_pad_set_activatepull_function (internal,
GST_DEBUG_FUNCPTR (gst_ghost_pad_internal_do_activate_pull));
gst_pad_set_activatepush_function (internal,
GST_DEBUG_FUNCPTR (gst_ghost_pad_internal_do_activate_push));
GST_PROXY_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_PROXY_UNLOCK (pad);
gst_object_unref (internal);
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) {
ret = g_object_new (GST_TYPE_GHOST_PAD, "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 (ret);
construct_failed:
/* already logged */
gst_object_unref (ret);
return NULL;
}
/**
* gst_ghost_pad_new_no_target:
* @name: 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: 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: the name of the new pad, or NULL to assign a default name.
* @target: 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: 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: the name of the new pad, or NULL to assign a default name.
* @target: the pad to ghost.
* @templ: 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: a new #GstPad, or NULL in case of an error.
*
* Since: 0.10.10
*/
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: the name of the new pad, or NULL to assign a default name.
* @templ: 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: a new #GstPad, or NULL in case of an error.
*
* Since: 0.10.10
*/
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: 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: 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;
gboolean result;
GstPadLinkReturn lret;
g_return_val_if_fail (GST_IS_GHOST_PAD (gpad), FALSE);
GST_PROXY_LOCK (gpad);
internal = GST_PROXY_PAD_INTERNAL (gpad);
g_assert (internal);
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_PROXY_PAD_TARGET (gpad))) {
if (GST_PAD_IS_SRC (oldtarget)) {
g_signal_handlers_disconnect_by_func (oldtarget,
(gpointer) on_src_target_notify, NULL);
}
GST_PROXY_PAD_RETARGET (internal) = TRUE;
/* unlink internal pad */
if (GST_PAD_IS_SRC (internal))
gst_pad_unlink (internal, oldtarget);
else
gst_pad_unlink (oldtarget, internal);
GST_PROXY_PAD_RETARGET (internal) = FALSE;
}
result = gst_proxy_pad_set_target_unlocked (GST_PAD_CAST (gpad), newtarget);
if (result && newtarget) {
if (GST_PAD_IS_SRC (newtarget)) {
g_signal_connect (newtarget, "notify::caps",
G_CALLBACK (on_src_target_notify), NULL);
}
/* and link to internal pad */
GST_DEBUG_OBJECT (gpad, "connecting internal pad to target");
if (GST_PAD_IS_SRC (internal))
lret = gst_pad_link (internal, newtarget);
else
lret = gst_pad_link (newtarget, internal);
if (lret != GST_PAD_LINK_OK)
goto link_failed;
}
GST_PROXY_UNLOCK (gpad);
return result;
/* ERRORS */
link_failed:
{
GST_WARNING_OBJECT (gpad, "could not link internal and target, reason:%d",
lret);
/* and unset target again */
gst_proxy_pad_set_target_unlocked (GST_PAD_CAST (gpad), NULL);
GST_PROXY_UNLOCK (gpad);
return FALSE;
}
}