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gstreamer/gst/gstpad.c
Hannes Bistry b47f425069 loadsave: fix requestpad handling and serialisation order. 
Support request pads when loading. Reverse pad serialisation order to
preserve it when recreating the pipeline.
2009-05-20 10:58:59 +03:00

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstpad.c: Pads for linking elements together
*
* 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:gstpad
* @short_description: Object contained by elements that allows links to
* other elements
* @see_also: #GstPadTemplate, #GstElement, #GstEvent
*
* A #GstElement is linked to other elements via "pads", which are extremely
* light-weight generic link points.
* After two pads are retrieved from an element with gst_element_get_pad(),
* the pads can be link with gst_pad_link(). (For quick links,
* you can also use gst_element_link(), which will make the obvious
* link for you if it's straightforward.)
*
* Pads are typically created from a #GstPadTemplate with
* gst_pad_new_from_template().
*
* Pads have #GstCaps attached to it to describe the media type they are
* capable of dealing with. gst_pad_get_caps() and gst_pad_set_caps() are
* used to manipulate the caps of the pads.
* Pads created from a pad template cannot set capabilities that are
* incompatible with the pad template capabilities.
*
* Pads without pad templates can be created with gst_pad_new(),
* which takes a direction and a name as an argument. If the name is NULL,
* then a guaranteed unique name will be assigned to it.
*
* gst_pad_get_parent() will retrieve the #GstElement that owns the pad.
*
* A #GstElement creating a pad will typically use the various
* gst_pad_set_*_function() calls to register callbacks for various events
* on the pads.
*
* GstElements will use gst_pad_push() and gst_pad_pull_range() to push out
* or pull in a buffer.
*
* To send a #GstEvent on a pad, use gst_pad_send_event() and
* gst_pad_push_event().
*
* Last reviewed on 2006-07-06 (0.10.9)
*/
#include "gst_private.h"
#include "gstpad.h"
#include "gstpadtemplate.h"
#include "gstenumtypes.h"
#include "gstmarshal.h"
#include "gstutils.h"
#include "gstinfo.h"
#include "gsterror.h"
#include "gstvalue.h"
#include "glib-compat-private.h"
GST_DEBUG_CATEGORY_STATIC (debug_dataflow);
#define GST_CAT_DEFAULT GST_CAT_PADS
/* Pad signals and args */
enum
{
PAD_LINKED,
PAD_UNLINKED,
PAD_REQUEST_LINK,
PAD_HAVE_DATA,
/* FILL ME */
LAST_SIGNAL
};
enum
{
PAD_PROP_0,
PAD_PROP_CAPS,
PAD_PROP_DIRECTION,
PAD_PROP_TEMPLATE,
/* FILL ME */
};
static void gst_pad_dispose (GObject * object);
static void gst_pad_finalize (GObject * object);
static void gst_pad_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_pad_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstFlowReturn handle_pad_block (GstPad * pad);
static GstCaps *gst_pad_get_caps_unlocked (GstPad * pad);
static void gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ);
static gboolean gst_pad_activate_default (GstPad * pad);
static gboolean gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_pad_save_thyself (GstObject * object, xmlNodePtr parent);
#endif
static GstObjectClass *parent_class = NULL;
static guint gst_pad_signals[LAST_SIGNAL] = { 0 };
/* quarks for probe signals */
static GQuark buffer_quark;
static GQuark event_quark;
typedef struct
{
const gint ret;
const gchar *name;
GQuark quark;
} GstFlowQuarks;
static GstFlowQuarks flow_quarks[] = {
{GST_FLOW_CUSTOM_SUCCESS, "custom-success", 0},
{GST_FLOW_RESEND, "resend", 0},
{GST_FLOW_OK, "ok", 0},
{GST_FLOW_NOT_LINKED, "not-linked", 0},
{GST_FLOW_WRONG_STATE, "wrong-state", 0},
{GST_FLOW_UNEXPECTED, "unexpected", 0},
{GST_FLOW_NOT_NEGOTIATED, "not-negotiated", 0},
{GST_FLOW_ERROR, "error", 0},
{GST_FLOW_NOT_SUPPORTED, "not-supported", 0},
{GST_FLOW_CUSTOM_ERROR, "custom-error", 0},
{0, NULL, 0}
};
/**
* gst_flow_get_name:
* @ret: a #GstFlowReturn to get the name of.
*
* Gets a string representing the given flow return.
*
* Returns: a static string with the name of the flow return.
*/
G_CONST_RETURN gchar *
gst_flow_get_name (GstFlowReturn ret)
{
gint i;
ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
for (i = 0; flow_quarks[i].name; i++) {
if (ret == flow_quarks[i].ret)
return flow_quarks[i].name;
}
return "unknown";
}
/**
* gst_flow_to_quark:
* @ret: a #GstFlowReturn to get the quark of.
*
* Get the unique quark for the given GstFlowReturn.
*
* Returns: the quark associated with the flow return or 0 if an
* invalid return was specified.
*/
GQuark
gst_flow_to_quark (GstFlowReturn ret)
{
gint i;
ret = CLAMP (ret, GST_FLOW_CUSTOM_ERROR, GST_FLOW_CUSTOM_SUCCESS);
for (i = 0; flow_quarks[i].name; i++) {
if (ret == flow_quarks[i].ret)
return flow_quarks[i].quark;
}
return 0;
}
#define _do_init \
{ \
gint i; \
\
buffer_quark = g_quark_from_static_string ("buffer"); \
event_quark = g_quark_from_static_string ("event"); \
\
for (i = 0; flow_quarks[i].name; i++) { \
flow_quarks[i].quark = g_quark_from_static_string (flow_quarks[i].name); \
} \
\
GST_DEBUG_CATEGORY_INIT (debug_dataflow, "GST_DATAFLOW", \
GST_DEBUG_BOLD | GST_DEBUG_FG_GREEN, "dataflow inside pads"); \
}
G_DEFINE_TYPE_WITH_CODE (GstPad, gst_pad, GST_TYPE_OBJECT, _do_init);
static gboolean
_gst_do_pass_data_accumulator (GSignalInvocationHint * ihint,
GValue * return_accu, const GValue * handler_return, gpointer dummy)
{
gboolean ret = g_value_get_boolean (handler_return);
GST_DEBUG ("accumulated %d", ret);
g_value_set_boolean (return_accu, ret);
return ret;
}
static gboolean
default_have_data (GstPad * pad, GstMiniObject * o)
{
return TRUE;
}
static void
gst_pad_class_init (GstPadClass * klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
gobject_class = G_OBJECT_CLASS (klass);
gstobject_class = GST_OBJECT_CLASS (klass);
parent_class = g_type_class_peek_parent (klass);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pad_dispose);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_pad_finalize);
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pad_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_pad_get_property);
/**
* GstPad::linked:
* @pad: the pad that emitted the signal
* @peer: the peer pad that has been connected
*
* Signals that a pad has been linked to the peer pad.
*/
gst_pad_signals[PAD_LINKED] =
g_signal_new ("linked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstPadClass, linked), NULL, NULL,
gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
/**
* GstPad::unlinked:
* @pad: the pad that emitted the signal
* @peer: the peer pad that has been disconnected
*
* Signals that a pad has been unlinked from the peer pad.
*/
gst_pad_signals[PAD_UNLINKED] =
g_signal_new ("unlinked", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstPadClass, unlinked), NULL, NULL,
gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);
/**
* GstPad::request-link:
* @pad: the pad that emitted the signal
* @peer: the peer pad for which a connection is requested
*
* Signals that a pad connection has been requested.
*/
gst_pad_signals[PAD_REQUEST_LINK] =
g_signal_new ("request-link", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstPadClass, request_link), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 0);
/**
* GstPad::have-data:
* @pad: the pad that emitted the signal
* @mini_obj: new data
*
* Signals that new data is available on the pad. This signal is used
* internally for implementing pad probes.
* See gst_pad_add_*_probe functions.
*
* Returns: %TRUE to keep the data, %FALSE to drop it
*/
gst_pad_signals[PAD_HAVE_DATA] =
g_signal_new ("have-data", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
G_STRUCT_OFFSET (GstPadClass, have_data),
_gst_do_pass_data_accumulator,
NULL, gst_marshal_BOOLEAN__POINTER, G_TYPE_BOOLEAN, 1,
GST_TYPE_MINI_OBJECT);
g_object_class_install_property (gobject_class, PAD_PROP_CAPS,
g_param_spec_boxed ("caps", "Caps", "The capabilities of the pad",
GST_TYPE_CAPS, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PAD_PROP_DIRECTION,
g_param_spec_enum ("direction", "Direction", "The direction of the pad",
GST_TYPE_PAD_DIRECTION, GST_PAD_UNKNOWN,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
/* FIXME, Make G_PARAM_CONSTRUCT_ONLY when we fix ghostpads. */
g_object_class_install_property (gobject_class, PAD_PROP_TEMPLATE,
g_param_spec_object ("template", "Template",
"The GstPadTemplate of this pad", GST_TYPE_PAD_TEMPLATE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
#ifndef GST_DISABLE_LOADSAVE
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_pad_save_thyself);
#endif
gstobject_class->path_string_separator = ".";
klass->have_data = default_have_data;
}
static void
gst_pad_init (GstPad * pad)
{
GST_PAD_DIRECTION (pad) = GST_PAD_UNKNOWN;
GST_PAD_PEER (pad) = NULL;
GST_PAD_CHAINFUNC (pad) = NULL;
GST_PAD_LINKFUNC (pad) = NULL;
GST_PAD_CAPS (pad) = NULL;
GST_PAD_GETCAPSFUNC (pad) = NULL;
GST_PAD_ACTIVATEFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_activate_default);
GST_PAD_EVENTFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_event_default);
GST_PAD_QUERYTYPEFUNC (pad) =
GST_DEBUG_FUNCPTR (gst_pad_get_query_types_default);
GST_PAD_QUERYFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_query_default);
GST_PAD_INTLINKFUNC (pad) =
GST_DEBUG_FUNCPTR (gst_pad_get_internal_links_default);
GST_PAD_ITERINTLINKFUNC (pad) =
GST_DEBUG_FUNCPTR (gst_pad_iterate_internal_links_default);
GST_PAD_ACCEPTCAPSFUNC (pad) = GST_DEBUG_FUNCPTR (gst_pad_acceptcaps_default);
pad->do_buffer_signals = 0;
pad->do_event_signals = 0;
GST_PAD_SET_FLUSHING (pad);
pad->preroll_lock = g_mutex_new ();
pad->preroll_cond = g_cond_new ();
pad->stream_rec_lock = g_new (GStaticRecMutex, 1);
g_static_rec_mutex_init (pad->stream_rec_lock);
pad->block_cond = g_cond_new ();
}
static void
gst_pad_dispose (GObject * object)
{
GstPad *pad = GST_PAD (object);
GstPad *peer;
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pad, "dispose");
/* unlink the peer pad */
if ((peer = gst_pad_get_peer (pad))) {
/* window for MT unsafeness, someone else could unlink here
* and then we call unlink with wrong pads. The unlink
* function would catch this and safely return failed. */
if (GST_PAD_IS_SRC (pad))
gst_pad_unlink (pad, peer);
else
gst_pad_unlink (peer, pad);
gst_object_unref (peer);
}
/* clear the caps */
gst_caps_replace (&GST_PAD_CAPS (pad), NULL);
gst_pad_set_pad_template (pad, NULL);
if (pad->block_destroy_data && pad->block_data) {
pad->block_destroy_data (pad->block_data);
pad->block_data = NULL;
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_pad_finalize (GObject * object)
{
GstPad *pad = GST_PAD (object);
GstTask *task;
/* in case the task is still around, clean it up */
if ((task = GST_PAD_TASK (pad))) {
gst_task_join (task);
GST_PAD_TASK (pad) = NULL;
gst_object_unref (task);
}
if (pad->stream_rec_lock) {
g_static_rec_mutex_free (pad->stream_rec_lock);
g_free (pad->stream_rec_lock);
pad->stream_rec_lock = NULL;
}
if (pad->preroll_lock) {
g_mutex_free (pad->preroll_lock);
g_cond_free (pad->preroll_cond);
pad->preroll_lock = NULL;
pad->preroll_cond = NULL;
}
if (pad->block_cond) {
g_cond_free (pad->block_cond);
pad->block_cond = NULL;
}
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_pad_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
g_return_if_fail (GST_IS_PAD (object));
switch (prop_id) {
case PAD_PROP_DIRECTION:
GST_PAD_DIRECTION (object) = g_value_get_enum (value);
break;
case PAD_PROP_TEMPLATE:
gst_pad_set_pad_template (GST_PAD_CAST (object),
(GstPadTemplate *) g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_pad_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
g_return_if_fail (GST_IS_PAD (object));
switch (prop_id) {
case PAD_PROP_CAPS:
GST_OBJECT_LOCK (object);
g_value_set_boxed (value, GST_PAD_CAPS (object));
GST_OBJECT_UNLOCK (object);
break;
case PAD_PROP_DIRECTION:
g_value_set_enum (value, GST_PAD_DIRECTION (object));
break;
case PAD_PROP_TEMPLATE:
g_value_set_object (value, GST_PAD_PAD_TEMPLATE (object));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* gst_pad_new:
* @name: the name of the new pad.
* @direction: the #GstPadDirection of the pad.
*
* Creates a new pad with the given name in the given direction.
* If name is NULL, a guaranteed unique name (across all pads)
* will be assigned.
* This function makes a copy of the name so you can safely free the name.
*
* Returns: a new #GstPad, or NULL in case of an error.
*
* MT safe.
*/
GstPad *
gst_pad_new (const gchar * name, GstPadDirection direction)
{
return g_object_new (GST_TYPE_PAD,
"name", name, "direction", direction, NULL);
}
/**
* gst_pad_new_from_template:
* @templ: the pad template to use
* @name: the name of the element
*
* Creates a new pad with the given name from the given template.
* If name is NULL, a guaranteed unique name (across all pads)
* will be assigned.
* This function makes a copy of the name so you can safely free the name.
*
* Returns: a new #GstPad, or NULL in case of an error.
*/
GstPad *
gst_pad_new_from_template (GstPadTemplate * templ, const gchar * name)
{
g_return_val_if_fail (GST_IS_PAD_TEMPLATE (templ), NULL);
return g_object_new (GST_TYPE_PAD,
"name", name, "direction", templ->direction, "template", templ, NULL);
}
/**
* gst_pad_new_from_static_template:
* @templ: the #GstStaticPadTemplate to use
* @name: the name of the element
*
* Creates a new pad with the given name from the given static template.
* If name is NULL, a guaranteed unique name (across all pads)
* will be assigned.
* This function makes a copy of the name so you can safely free the name.
*
* Returns: a new #GstPad, or NULL in case of an error.
*/
GstPad *
gst_pad_new_from_static_template (GstStaticPadTemplate * templ,
const gchar * name)
{
GstPad *pad;
GstPadTemplate *template;
template = gst_static_pad_template_get (templ);
pad = gst_pad_new_from_template (template, name);
gst_object_unref (template);
return pad;
}
/**
* gst_pad_get_direction:
* @pad: a #GstPad to get the direction of.
*
* Gets the direction of the pad. The direction of the pad is
* decided at construction time so this function does not take
* the LOCK.
*
* Returns: the #GstPadDirection of the pad.
*
* MT safe.
*/
GstPadDirection
gst_pad_get_direction (GstPad * pad)
{
GstPadDirection result;
/* PAD_UNKNOWN is a little silly but we need some sort of
* error return value */
g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_UNKNOWN);
result = GST_PAD_DIRECTION (pad);
return result;
}
static gboolean
gst_pad_activate_default (GstPad * pad)
{
return gst_pad_activate_push (pad, TRUE);
}
static void
pre_activate (GstPad * pad, GstActivateMode new_mode)
{
switch (new_mode) {
case GST_ACTIVATE_PUSH:
case GST_ACTIVATE_PULL:
GST_OBJECT_LOCK (pad);
GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE %d, unset flushing",
new_mode);
GST_PAD_UNSET_FLUSHING (pad);
GST_PAD_ACTIVATE_MODE (pad) = new_mode;
GST_OBJECT_UNLOCK (pad);
break;
case GST_ACTIVATE_NONE:
GST_OBJECT_LOCK (pad);
GST_DEBUG_OBJECT (pad, "setting ACTIVATE_MODE NONE, set flushing");
GST_PAD_SET_FLUSHING (pad);
GST_PAD_ACTIVATE_MODE (pad) = new_mode;
/* unlock blocked pads so element can resume and stop */
GST_PAD_BLOCK_BROADCAST (pad);
GST_OBJECT_UNLOCK (pad);
break;
}
}
static void
post_activate (GstPad * pad, GstActivateMode new_mode)
{
switch (new_mode) {
case GST_ACTIVATE_PUSH:
case GST_ACTIVATE_PULL:
/* nop */
break;
case GST_ACTIVATE_NONE:
/* ensures that streaming stops */
GST_PAD_STREAM_LOCK (pad);
GST_DEBUG_OBJECT (pad, "stopped streaming");
GST_PAD_STREAM_UNLOCK (pad);
break;
}
}
/**
* gst_pad_set_active:
* @pad: the #GstPad to activate or deactivate.
* @active: whether or not the pad should be active.
*
* Activates or deactivates the given pad.
* Normally called from within core state change functions.
*
* If @active, makes sure the pad is active. If it is already active, either in
* push or pull mode, just return. Otherwise dispatches to the pad's activate
* function to perform the actual activation.
*
* If not @active, checks the pad's current mode and calls
* gst_pad_activate_push() or gst_pad_activate_pull(), as appropriate, with a
* FALSE argument.
*
* Returns: #TRUE if the operation was successful.
*
* MT safe.
*/
gboolean
gst_pad_set_active (GstPad * pad, gboolean active)
{
GstActivateMode old;
gboolean ret = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
old = GST_PAD_ACTIVATE_MODE (pad);
GST_OBJECT_UNLOCK (pad);
if (active) {
switch (old) {
case GST_ACTIVATE_PUSH:
GST_DEBUG_OBJECT (pad, "activating pad from push");
ret = TRUE;
break;
case GST_ACTIVATE_PULL:
GST_DEBUG_OBJECT (pad, "activating pad from pull");
ret = TRUE;
break;
case GST_ACTIVATE_NONE:
GST_DEBUG_OBJECT (pad, "activating pad from none");
ret = (GST_PAD_ACTIVATEFUNC (pad)) (pad);
break;
}
} else {
switch (old) {
case GST_ACTIVATE_PUSH:
GST_DEBUG_OBJECT (pad, "deactivating pad from push");
ret = gst_pad_activate_push (pad, FALSE);
break;
case GST_ACTIVATE_PULL:
GST_DEBUG_OBJECT (pad, "deactivating pad from pull");
ret = gst_pad_activate_pull (pad, FALSE);
break;
case GST_ACTIVATE_NONE:
GST_DEBUG_OBJECT (pad, "deactivating pad from none");
ret = TRUE;
break;
}
}
if (!ret) {
GST_OBJECT_LOCK (pad);
if (!active) {
g_critical ("Failed to deactivate pad %s:%s, very bad",
GST_DEBUG_PAD_NAME (pad));
} else {
GST_WARNING_OBJECT (pad, "Failed to activate pad");
}
GST_OBJECT_UNLOCK (pad);
}
return ret;
}
/**
* gst_pad_activate_pull:
* @pad: the #GstPad to activate or deactivate.
* @active: whether or not the pad should be active.
*
* Activates or deactivates the given pad in pull mode via dispatching to the
* pad's activatepullfunc. For use from within pad activation functions only.
* When called on sink pads, will first proxy the call to the peer pad, which
* is expected to activate its internally linked pads from within its
* activate_pull function.
*
* If you don't know what this is, you probably don't want to call it.
*
* Returns: TRUE if the operation was successful.
*
* MT safe.
*/
gboolean
gst_pad_activate_pull (GstPad * pad, gboolean active)
{
GstActivateMode old, new;
GstPad *peer;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
old = GST_PAD_ACTIVATE_MODE (pad);
GST_OBJECT_UNLOCK (pad);
if (active) {
switch (old) {
case GST_ACTIVATE_PULL:
GST_DEBUG_OBJECT (pad, "activating pad from pull, was ok");
goto was_ok;
case GST_ACTIVATE_PUSH:
GST_DEBUG_OBJECT (pad,
"activating pad from push, deactivate push first");
/* pad was activate in the wrong direction, deactivate it
* and reactivate it in pull mode */
if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
goto deactivate_failed;
/* fallthrough, pad is deactivated now. */
case GST_ACTIVATE_NONE:
GST_DEBUG_OBJECT (pad, "activating pad from none");
break;
}
} else {
switch (old) {
case GST_ACTIVATE_NONE:
GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok");
goto was_ok;
case GST_ACTIVATE_PUSH:
GST_DEBUG_OBJECT (pad, "deactivating pad from push, weird");
/* pad was activated in the other direction, deactivate it
* in push mode, this should not happen... */
if (G_UNLIKELY (!gst_pad_activate_push (pad, FALSE)))
goto deactivate_failed;
/* everything is fine now */
goto was_ok;
case GST_ACTIVATE_PULL:
GST_DEBUG_OBJECT (pad, "deactivating pad from pull");
break;
}
}
if (gst_pad_get_direction (pad) == GST_PAD_SINK) {
if ((peer = gst_pad_get_peer (pad))) {
GST_DEBUG_OBJECT (pad, "calling peer");
if (G_UNLIKELY (!gst_pad_activate_pull (peer, active)))
goto peer_failed;
gst_object_unref (peer);
} else {
/* there is no peer, this is only fatal when we activate. When we
* deactivate, we must assume the application has unlinked the peer and
* will deactivate it eventually. */
if (active)
goto not_linked;
else
GST_DEBUG_OBJECT (pad, "deactivating unlinked pad");
}
} else {
if (G_UNLIKELY (GST_PAD_GETRANGEFUNC (pad) == NULL))
goto failure; /* Can't activate pull on a src without a
getrange function */
}
new = active ? GST_ACTIVATE_PULL : GST_ACTIVATE_NONE;
pre_activate (pad, new);
if (GST_PAD_ACTIVATEPULLFUNC (pad)) {
if (G_UNLIKELY (!GST_PAD_ACTIVATEPULLFUNC (pad) (pad, active)))
goto failure;
} else {
/* can happen for sinks of passthrough elements */
}
post_activate (pad, new);
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in pull mode",
active ? "activated" : "deactivated");
return TRUE;
was_ok:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in pull mode",
active ? "activated" : "deactivated");
return TRUE;
}
deactivate_failed:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"failed to %s in switch to pull from mode %d",
(active ? "activate" : "deactivate"), old);
return FALSE;
}
peer_failed:
{
GST_OBJECT_LOCK (peer);
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"activate_pull on peer (%s:%s) failed", GST_DEBUG_PAD_NAME (peer));
GST_OBJECT_UNLOCK (peer);
gst_object_unref (peer);
return FALSE;
}
not_linked:
{
GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "can't activate unlinked sink "
"pad in pull mode");
return FALSE;
}
failure:
{
GST_OBJECT_LOCK (pad);
GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in pull mode",
active ? "activate" : "deactivate");
GST_PAD_SET_FLUSHING (pad);
GST_PAD_ACTIVATE_MODE (pad) = old;
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_pad_activate_push:
* @pad: the #GstPad to activate or deactivate.
* @active: whether the pad should be active or not.
*
* Activates or deactivates the given pad in push mode via dispatching to the
* pad's activatepushfunc. For use from within pad activation functions only.
*
* If you don't know what this is, you probably don't want to call it.
*
* Returns: %TRUE if the operation was successful.
*
* MT safe.
*/
gboolean
gst_pad_activate_push (GstPad * pad, gboolean active)
{
GstActivateMode old, new;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "trying to set %s in push mode",
active ? "activated" : "deactivated");
GST_OBJECT_LOCK (pad);
old = GST_PAD_ACTIVATE_MODE (pad);
GST_OBJECT_UNLOCK (pad);
if (active) {
switch (old) {
case GST_ACTIVATE_PUSH:
GST_DEBUG_OBJECT (pad, "activating pad from push, was ok");
goto was_ok;
case GST_ACTIVATE_PULL:
GST_DEBUG_OBJECT (pad,
"activating pad from push, deactivating pull first");
/* pad was activate in the wrong direction, deactivate it
* an reactivate it in push mode */
if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
goto deactivate_failed;
/* fallthrough, pad is deactivated now. */
case GST_ACTIVATE_NONE:
GST_DEBUG_OBJECT (pad, "activating pad from none");
break;
}
} else {
switch (old) {
case GST_ACTIVATE_NONE:
GST_DEBUG_OBJECT (pad, "deactivating pad from none, was ok");
goto was_ok;
case GST_ACTIVATE_PULL:
GST_DEBUG_OBJECT (pad, "deactivating pad from pull, weird");
/* pad was activated in the other direction, deactivate it
* in pull mode, this should not happen... */
if (G_UNLIKELY (!gst_pad_activate_pull (pad, FALSE)))
goto deactivate_failed;
/* everything is fine now */
goto was_ok;
case GST_ACTIVATE_PUSH:
GST_DEBUG_OBJECT (pad, "deactivating pad from push");
break;
}
}
new = active ? GST_ACTIVATE_PUSH : GST_ACTIVATE_NONE;
pre_activate (pad, new);
if (GST_PAD_ACTIVATEPUSHFUNC (pad)) {
if (G_UNLIKELY (!GST_PAD_ACTIVATEPUSHFUNC (pad) (pad, active))) {
goto failure;
}
} else {
/* quite ok, element relies on state change func to prepare itself */
}
post_activate (pad, new);
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "%s in push mode",
active ? "activated" : "deactivated");
return TRUE;
was_ok:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "already %s in push mode",
active ? "activated" : "deactivated");
return TRUE;
}
deactivate_failed:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"failed to %s in switch to push from mode %d",
(active ? "activate" : "deactivate"), old);
return FALSE;
}
failure:
{
GST_OBJECT_LOCK (pad);
GST_CAT_INFO_OBJECT (GST_CAT_PADS, pad, "failed to %s in push mode",
active ? "activate" : "deactivate");
GST_PAD_SET_FLUSHING (pad);
GST_PAD_ACTIVATE_MODE (pad) = old;
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_pad_is_active:
* @pad: the #GstPad to query
*
* Query if a pad is active
*
* Returns: TRUE if the pad is active.
*
* MT safe.
*/
gboolean
gst_pad_is_active (GstPad * pad)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
result = GST_PAD_MODE_ACTIVATE (GST_PAD_ACTIVATE_MODE (pad));
GST_OBJECT_UNLOCK (pad);
return result;
}
/**
* gst_pad_set_blocked_async_full:
* @pad: the #GstPad to block or unblock
* @blocked: boolean indicating whether the pad should be blocked or unblocked
* @callback: #GstPadBlockCallback that will be called when the
* operation succeeds
* @user_data: user data passed to the callback
* @destroy_data: #GDestroyNotify for user_data
*
* Blocks or unblocks the dataflow on a pad. The provided callback
* is called when the operation succeeds; this happens right before the next
* attempt at pushing a buffer on the pad.
*
* This can take a while as the pad can only become blocked when real dataflow
* is happening.
* When the pipeline is stalled, for example in PAUSED, this can
* take an indeterminate amount of time.
* You can pass NULL as the callback to make this call block. Be careful with
* this blocking call as it might not return for reasons stated above.
*
* Returns: TRUE if the pad could be blocked. This function can fail if the
* wrong parameters were passed or the pad was already in the requested state.
*
* MT safe.
*
* Since: 0.10.23
*/
gboolean
gst_pad_set_blocked_async_full (GstPad * pad, gboolean blocked,
GstPadBlockCallback callback, gpointer user_data,
GDestroyNotify destroy_data)
{
gboolean was_blocked = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
was_blocked = GST_PAD_IS_BLOCKED (pad);
if (G_UNLIKELY (was_blocked == blocked))
goto had_right_state;
if (blocked) {
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocking pad");
GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKED);
if (pad->block_destroy_data && pad->block_data &&
pad->block_data != user_data)
pad->block_destroy_data (pad->block_data);
pad->block_callback = callback;
pad->block_data = user_data;
pad->block_destroy_data = destroy_data;
pad->abidata.ABI.block_callback_called = FALSE;
if (!callback) {
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for block");
GST_PAD_BLOCK_WAIT (pad);
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "blocked");
}
} else {
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocking pad");
GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKED);
if (pad->block_destroy_data && pad->block_data &&
pad->block_data != user_data)
pad->block_destroy_data (pad->block_data);
pad->block_callback = callback;
pad->block_data = user_data;
pad->block_destroy_data = destroy_data;
pad->abidata.ABI.block_callback_called = FALSE;
GST_PAD_BLOCK_BROADCAST (pad);
if (!callback) {
/* no callback, wait for the unblock to happen */
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "waiting for unblock");
GST_PAD_BLOCK_WAIT (pad);
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "unblocked");
}
}
GST_OBJECT_UNLOCK (pad);
return TRUE;
had_right_state:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pad was in right state (%d)", was_blocked);
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_pad_set_blocked_async:
* @pad: the #GstPad to block or unblock
* @blocked: boolean indicating whether the pad should be blocked or unblocked
* @callback: #GstPadBlockCallback that will be called when the
* operation succeeds
* @user_data: user data passed to the callback
*
* Blocks or unblocks the dataflow on a pad. The provided callback
* is called when the operation succeeds; this happens right before the next
* attempt at pushing a buffer on the pad.
*
* This can take a while as the pad can only become blocked when real dataflow
* is happening.
* When the pipeline is stalled, for example in PAUSED, this can
* take an indeterminate amount of time.
* You can pass NULL as the callback to make this call block. Be careful with
* this blocking call as it might not return for reasons stated above.
*
* Returns: TRUE if the pad could be blocked. This function can fail if the
* wrong parameters were passed or the pad was already in the requested state.
*
* MT safe.
*/
gboolean
gst_pad_set_blocked_async (GstPad * pad, gboolean blocked,
GstPadBlockCallback callback, gpointer user_data)
{
return gst_pad_set_blocked_async_full (pad, blocked,
callback, user_data, NULL);
}
/**
* gst_pad_set_blocked:
* @pad: the #GstPad to block or unblock
* @blocked: boolean indicating we should block or unblock
*
* Blocks or unblocks the dataflow on a pad. This function is
* a shortcut for gst_pad_set_blocked_async() with a NULL
* callback.
*
* Returns: TRUE if the pad could be blocked. This function can fail if the
* wrong parameters were passed or the pad was already in the requested state.
*
* MT safe.
*/
gboolean
gst_pad_set_blocked (GstPad * pad, gboolean blocked)
{
return gst_pad_set_blocked_async (pad, blocked, NULL, NULL);
}
/**
* gst_pad_is_blocked:
* @pad: the #GstPad to query
*
* Checks if the pad is blocked or not. This function returns the
* last requested state of the pad. It is not certain that the pad
* is actually blocking at this point (see gst_pad_is_blocking()).
*
* Returns: TRUE if the pad is blocked.
*
* MT safe.
*/
gboolean
gst_pad_is_blocked (GstPad * pad)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), result);
GST_OBJECT_LOCK (pad);
result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED);
GST_OBJECT_UNLOCK (pad);
return result;
}
/**
* gst_pad_is_blocking:
* @pad: the #GstPad to query
*
* Checks if the pad is blocking or not. This is a guaranteed state
* of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.
*
* Returns: TRUE if the pad is blocking.
*
* MT safe.
*
* Since: 0.10.11
*/
gboolean
gst_pad_is_blocking (GstPad * pad)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), result);
GST_OBJECT_LOCK (pad);
/* the blocking flag is only valid if the pad is not flushing */
result = GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING) &&
!GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING);
GST_OBJECT_UNLOCK (pad);
return result;
}
/**
* gst_pad_set_activate_function:
* @pad: a #GstPad.
* @activate: the #GstPadActivateFunction to set.
*
* Sets the given activate function for @pad. The activate function will
* dispatch to gst_pad_activate_push() or gst_pad_activate_pull() to perform
* the actual activation. Only makes sense to set on sink pads.
*
* Call this function if your sink pad can start a pull-based task.
*/
void
gst_pad_set_activate_function (GstPad * pad, GstPadActivateFunction activate)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_ACTIVATEFUNC (pad) = activate;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatefunc set to %s",
GST_DEBUG_FUNCPTR_NAME (activate));
}
/**
* gst_pad_set_activatepull_function:
* @pad: a #GstPad.
* @activatepull: the #GstPadActivateModeFunction to set.
*
* Sets the given activate_pull function for the pad. An activate_pull function
* prepares the element and any upstream connections for pulling. See XXX
* part-activation.txt for details.
*/
void
gst_pad_set_activatepull_function (GstPad * pad,
GstPadActivateModeFunction activatepull)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_ACTIVATEPULLFUNC (pad) = activatepull;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepullfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (activatepull));
}
/**
* gst_pad_set_activatepush_function:
* @pad: a #GstPad.
* @activatepush: the #GstPadActivateModeFunction to set.
*
* Sets the given activate_push function for the pad. An activate_push function
* prepares the element for pushing. See XXX part-activation.txt for details.
*/
void
gst_pad_set_activatepush_function (GstPad * pad,
GstPadActivateModeFunction activatepush)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_ACTIVATEPUSHFUNC (pad) = activatepush;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "activatepushfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (activatepush));
}
/**
* gst_pad_set_chain_function:
* @pad: a sink #GstPad.
* @chain: the #GstPadChainFunction to set.
*
* Sets the given chain function for the pad. The chain function is called to
* process a #GstBuffer input buffer. see #GstPadChainFunction for more details.
*/
void
gst_pad_set_chain_function (GstPad * pad, GstPadChainFunction chain)
{
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (GST_PAD_IS_SINK (pad));
GST_PAD_CHAINFUNC (pad) = chain;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (chain));
}
/**
* gst_pad_set_chain_list_function:
* @pad: a sink #GstPad.
* @chainlist: the #GstPadChainListFunction to set.
*
* Sets the given chain list function for the pad. The chainlist function is
* called to process a #GstBufferList input buffer list. See
* #GstPadChainListFunction for more details.
*
* Since: 0.10.24
*/
void
gst_pad_set_chain_list_function (GstPad * pad,
GstPadChainListFunction chainlist)
{
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (GST_PAD_IS_SINK (pad));
GST_PAD_CHAINLISTFUNC (pad) = chainlist;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "chainlistfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (chainlist));
}
/**
* gst_pad_set_getrange_function:
* @pad: a source #GstPad.
* @get: the #GstPadGetRangeFunction to set.
*
* Sets the given getrange function for the pad. The getrange function is
* called to produce a new #GstBuffer to start the processing pipeline. see
* #GstPadGetRangeFunction for a description of the getrange function.
*/
void
gst_pad_set_getrange_function (GstPad * pad, GstPadGetRangeFunction get)
{
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (GST_PAD_IS_SRC (pad));
GST_PAD_GETRANGEFUNC (pad) = get;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getrangefunc set to %s",
GST_DEBUG_FUNCPTR_NAME (get));
}
/**
* gst_pad_set_checkgetrange_function:
* @pad: a source #GstPad.
* @check: the #GstPadCheckGetRangeFunction to set.
*
* Sets the given checkgetrange function for the pad. Implement this function
* on a pad if you dynamically support getrange based scheduling on the pad.
*/
void
gst_pad_set_checkgetrange_function (GstPad * pad,
GstPadCheckGetRangeFunction check)
{
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (GST_PAD_IS_SRC (pad));
GST_PAD_CHECKGETRANGEFUNC (pad) = check;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "checkgetrangefunc set to %s",
GST_DEBUG_FUNCPTR_NAME (check));
}
/**
* gst_pad_set_event_function:
* @pad: a #GstPad of either direction.
* @event: the #GstPadEventFunction to set.
*
* Sets the given event handler for the pad.
*/
void
gst_pad_set_event_function (GstPad * pad, GstPadEventFunction event)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_EVENTFUNC (pad) = event;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "eventfunc for set to %s",
GST_DEBUG_FUNCPTR_NAME (event));
}
/**
* gst_pad_set_query_function:
* @pad: a #GstPad of either direction.
* @query: the #GstPadQueryFunction to set.
*
* Set the given query function for the pad.
*/
void
gst_pad_set_query_function (GstPad * pad, GstPadQueryFunction query)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_QUERYFUNC (pad) = query;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "queryfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (query));
}
/**
* gst_pad_set_query_type_function:
* @pad: a #GstPad of either direction.
* @type_func: the #GstPadQueryTypeFunction to set.
*
* Set the given query type function for the pad.
*/
void
gst_pad_set_query_type_function (GstPad * pad,
GstPadQueryTypeFunction type_func)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_QUERYTYPEFUNC (pad) = type_func;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "querytypefunc set to %s",
GST_DEBUG_FUNCPTR_NAME (type_func));
}
/**
* gst_pad_get_query_types:
* @pad: a #GstPad.
*
* Get an array of supported queries that can be performed
* on this pad.
*
* Returns: a zero-terminated array of #GstQueryType.
*/
const GstQueryType *
gst_pad_get_query_types (GstPad * pad)
{
GstPadQueryTypeFunction func;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
if (G_UNLIKELY ((func = GST_PAD_QUERYTYPEFUNC (pad)) == NULL))
goto no_func;
return func (pad);
no_func:
{
return NULL;
}
}
static gboolean
gst_pad_get_query_types_dispatcher (GstPad * pad, const GstQueryType ** data)
{
*data = gst_pad_get_query_types (pad);
return TRUE;
}
/**
* gst_pad_get_query_types_default:
* @pad: a #GstPad.
*
* Invoke the default dispatcher for the query types on
* the pad.
*
* Returns: an zero-terminated array of #GstQueryType, or NULL if none of the
* internally-linked pads has a query types function.
*/
const GstQueryType *
gst_pad_get_query_types_default (GstPad * pad)
{
GstQueryType *result = NULL;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
gst_pad_dispatcher (pad, (GstPadDispatcherFunction)
gst_pad_get_query_types_dispatcher, &result);
return result;
}
/**
* gst_pad_set_iterate_internal_links_function:
* @pad: a #GstPad of either direction.
* @iterintlink: the #GstPadIterIntLinkFunction to set.
*
* Sets the given internal link iterator function for the pad.
*
* Since: 0.10.21
*/
void
gst_pad_set_iterate_internal_links_function (GstPad * pad,
GstPadIterIntLinkFunction iterintlink)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_ITERINTLINKFUNC (pad) = iterintlink;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link iterator set to %s",
GST_DEBUG_FUNCPTR_NAME (iterintlink));
}
/**
* gst_pad_set_internal_link_function:
* @pad: a #GstPad of either direction.
* @intlink: the #GstPadIntLinkFunction to set.
*
* Sets the given internal link function for the pad.
*
* Deprecated: Use the thread-safe gst_pad_set_iterate_internal_links_function()
*/
#ifndef GST_REMOVE_DEPRECATED
void
gst_pad_set_internal_link_function (GstPad * pad, GstPadIntLinkFunction intlink)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_INTLINKFUNC (pad) = intlink;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "internal link set to %s",
GST_DEBUG_FUNCPTR_NAME (intlink));
}
#endif /* GST_REMOVE_DEPRECATED */
/**
* gst_pad_set_link_function:
* @pad: a #GstPad.
* @link: the #GstPadLinkFunction to set.
*
* Sets the given link function for the pad. It will be called when
* the pad is linked with another pad.
*
* The return value #GST_PAD_LINK_OK should be used when the connection can be
* made.
*
* The return value #GST_PAD_LINK_REFUSED should be used when the connection
* cannot be made for some reason.
*
* If @link is installed on a source pad, it should call the #GstPadLinkFunction
* of the peer sink pad, if present.
*/
void
gst_pad_set_link_function (GstPad * pad, GstPadLinkFunction link)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_LINKFUNC (pad) = link;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "linkfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (link));
}
/**
* gst_pad_set_unlink_function:
* @pad: a #GstPad.
* @unlink: the #GstPadUnlinkFunction to set.
*
* Sets the given unlink function for the pad. It will be called
* when the pad is unlinked.
*/
void
gst_pad_set_unlink_function (GstPad * pad, GstPadUnlinkFunction unlink)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_UNLINKFUNC (pad) = unlink;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "unlinkfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (unlink));
}
/**
* gst_pad_set_getcaps_function:
* @pad: a #GstPad.
* @getcaps: the #GstPadGetCapsFunction to set.
*
* Sets the given getcaps function for the pad. @getcaps should return the
* allowable caps for a pad in the context of the element's state, its link to
* other elements, and the devices or files it has opened. These caps must be a
* subset of the pad template caps. In the NULL state with no links, @getcaps
* should ideally return the same caps as the pad template. In rare
* circumstances, an object property can affect the caps returned by @getcaps,
* but this is discouraged.
*
* You do not need to call this function if @pad's allowed caps are always the
* same as the pad template caps. This can only be true if the padtemplate
* has fixed simple caps.
*
* For most filters, the caps returned by @getcaps is directly affected by the
* allowed caps on other pads. For demuxers and decoders, the caps returned by
* the srcpad's getcaps function is directly related to the stream data. Again,
* @getcaps should return the most specific caps it reasonably can, since this
* helps with autoplugging.
*
* Note that the return value from @getcaps is owned by the caller, so the
* caller should unref the caps after usage.
*/
void
gst_pad_set_getcaps_function (GstPad * pad, GstPadGetCapsFunction getcaps)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_GETCAPSFUNC (pad) = getcaps;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "getcapsfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (getcaps));
}
/**
* gst_pad_set_acceptcaps_function:
* @pad: a #GstPad.
* @acceptcaps: the #GstPadAcceptCapsFunction to set.
*
* Sets the given acceptcaps function for the pad. The acceptcaps function
* will be called to check if the pad can accept the given caps. Setting the
* acceptcaps function to NULL restores the default behaviour of allowing
* any caps that matches the caps from gst_pad_get_caps.
*/
void
gst_pad_set_acceptcaps_function (GstPad * pad,
GstPadAcceptCapsFunction acceptcaps)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_ACCEPTCAPSFUNC (pad) = acceptcaps;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "acceptcapsfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (acceptcaps));
}
/**
* gst_pad_set_fixatecaps_function:
* @pad: a #GstPad.
* @fixatecaps: the #GstPadFixateCapsFunction to set.
*
* Sets the given fixatecaps function for the pad. The fixatecaps function
* will be called whenever the default values for a GstCaps needs to be
* filled in.
*/
void
gst_pad_set_fixatecaps_function (GstPad * pad,
GstPadFixateCapsFunction fixatecaps)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_FIXATECAPSFUNC (pad) = fixatecaps;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fixatecapsfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (fixatecaps));
}
/**
* gst_pad_set_setcaps_function:
* @pad: a #GstPad.
* @setcaps: the #GstPadSetCapsFunction to set.
*
* Sets the given setcaps function for the pad. The setcaps function
* will be called whenever a buffer with a new media type is pushed or
* pulled from the pad. The pad/element needs to update its internal
* structures to process the new media type. If this new type is not
* acceptable, the setcaps function should return FALSE.
*/
void
gst_pad_set_setcaps_function (GstPad * pad, GstPadSetCapsFunction setcaps)
{
g_return_if_fail (GST_IS_PAD (pad));
GST_PAD_SETCAPSFUNC (pad) = setcaps;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "setcapsfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (setcaps));
}
/**
* gst_pad_set_bufferalloc_function:
* @pad: a sink #GstPad.
* @bufalloc: the #GstPadBufferAllocFunction to set.
*
* Sets the given bufferalloc function for the pad. Note that the
* bufferalloc function can only be set on sinkpads.
*/
void
gst_pad_set_bufferalloc_function (GstPad * pad,
GstPadBufferAllocFunction bufalloc)
{
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (GST_PAD_IS_SINK (pad));
GST_PAD_BUFFERALLOCFUNC (pad) = bufalloc;
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "bufferallocfunc set to %s",
GST_DEBUG_FUNCPTR_NAME (bufalloc));
}
/**
* gst_pad_unlink:
* @srcpad: the source #GstPad to unlink.
* @sinkpad: the sink #GstPad to unlink.
*
* Unlinks the source pad from the sink pad. Will emit the #GstPad::unlinked
* signal on both pads.
*
* Returns: TRUE if the pads were unlinked. This function returns FALSE if
* the pads were not linked together.
*
* MT safe.
*/
gboolean
gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
{
gboolean result = FALSE;
GstElement *parent = NULL;
g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), FALSE);
g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
g_return_val_if_fail (GST_PAD_IS_SINK (sinkpad), FALSE);
GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinking %s:%s(%p) and %s:%s(%p)",
GST_DEBUG_PAD_NAME (srcpad), srcpad,
GST_DEBUG_PAD_NAME (sinkpad), sinkpad);
/* We need to notify the parent before taking any pad locks as the bin in
* question might be waiting for a lock on the pad while holding its lock
* that our message will try to take. */
if ((parent = GST_ELEMENT_CAST (gst_pad_get_parent (srcpad)))) {
if (GST_IS_ELEMENT (parent)) {
gst_element_post_message (parent,
gst_message_new_structure_change (GST_OBJECT_CAST (srcpad),
GST_STRUCTURE_CHANGE_TYPE_PAD_UNLINK, parent, TRUE));
} else {
gst_object_unref (parent);
parent = NULL;
}
}
GST_OBJECT_LOCK (srcpad);
GST_OBJECT_LOCK (sinkpad);
if (G_UNLIKELY (GST_PAD_PEER (srcpad) != sinkpad))
goto not_linked_together;
if (GST_PAD_UNLINKFUNC (srcpad)) {
GST_PAD_UNLINKFUNC (srcpad) (srcpad);
}
if (GST_PAD_UNLINKFUNC (sinkpad)) {
GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
}
/* first clear peers */
GST_PAD_PEER (srcpad) = NULL;
GST_PAD_PEER (sinkpad) = NULL;
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
/* fire off a signal to each of the pads telling them
* that they've been unlinked */
g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_UNLINKED], 0, sinkpad);
g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_UNLINKED], 0, srcpad);
GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "unlinked %s:%s and %s:%s",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
result = TRUE;
done:
if (parent != NULL) {
gst_element_post_message (parent,
gst_message_new_structure_change (GST_OBJECT_CAST (srcpad),
GST_STRUCTURE_CHANGE_TYPE_PAD_UNLINK, parent, FALSE));
gst_object_unref (parent);
}
return result;
/* ERRORS */
not_linked_together:
{
/* we do not emit a warning in this case because unlinking cannot
* be made MT safe.*/
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
goto done;
}
}
/**
* gst_pad_is_linked:
* @pad: pad to check
*
* Checks if a @pad is linked to another pad or not.
*
* Returns: TRUE if the pad is linked, FALSE otherwise.
*
* MT safe.
*/
gboolean
gst_pad_is_linked (GstPad * pad)
{
gboolean result;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
result = (GST_PAD_PEER (pad) != NULL);
GST_OBJECT_UNLOCK (pad);
return result;
}
/* get the caps from both pads and see if the intersection
* is not empty.
*
* This function should be called with the pad LOCK on both
* pads
*/
static gboolean
gst_pad_link_check_compatible_unlocked (GstPad * src, GstPad * sink)
{
GstCaps *srccaps;
GstCaps *sinkcaps;
GstCaps *icaps;
srccaps = gst_pad_get_caps_unlocked (src);
sinkcaps = gst_pad_get_caps_unlocked (sink);
GST_CAT_DEBUG (GST_CAT_CAPS, "src caps %" GST_PTR_FORMAT, srccaps);
GST_CAT_DEBUG (GST_CAT_CAPS, "sink caps %" GST_PTR_FORMAT, sinkcaps);
/* if we have caps on both pads we can check the intersection. If one
* of the caps is NULL, we return TRUE. */
if (srccaps == NULL || sinkcaps == NULL) {
if (srccaps)
gst_caps_unref (srccaps);
if (sinkcaps)
gst_caps_unref (sinkcaps);
goto done;
}
icaps = gst_caps_intersect (srccaps, sinkcaps);
gst_caps_unref (srccaps);
gst_caps_unref (sinkcaps);
if (icaps == NULL)
goto was_null;
GST_CAT_DEBUG (GST_CAT_CAPS,
"intersection caps %p %" GST_PTR_FORMAT, icaps, icaps);
if (gst_caps_is_empty (icaps))
goto was_empty;
gst_caps_unref (icaps);
done:
return TRUE;
/* incompatible cases */
was_null:
{
GST_CAT_DEBUG (GST_CAT_CAPS, "intersection gave NULL");
return FALSE;
}
was_empty:
{
GST_CAT_DEBUG (GST_CAT_CAPS, "intersection is EMPTY");
gst_caps_unref (icaps);
return FALSE;
}
}
/* check if the grandparents of both pads are the same.
* This check is required so that we don't try to link
* pads from elements in different bins without ghostpads.
*
* The LOCK should be held on both pads
*/
static gboolean
gst_pad_link_check_hierarchy (GstPad * src, GstPad * sink)
{
GstObject *psrc, *psink;
psrc = GST_OBJECT_PARENT (src);
psink = GST_OBJECT_PARENT (sink);
/* if one of the pads has no parent, we allow the link */
if (G_UNLIKELY (psrc == NULL || psink == NULL))
goto no_parent;
/* only care about parents that are elements */
if (G_UNLIKELY (!GST_IS_ELEMENT (psrc) || !GST_IS_ELEMENT (psink)))
goto no_element_parent;
/* if the parents are the same, we have a loop */
if (G_UNLIKELY (psrc == psink))
goto same_parents;
/* if they both have a parent, we check the grandparents. We can not lock
* the parent because we hold on the child (pad) and the locking order is
* parent >> child. */
psrc = GST_OBJECT_PARENT (psrc);
psink = GST_OBJECT_PARENT (psink);
/* if they have grandparents but they are not the same */
if (G_UNLIKELY (psrc != psink))
goto wrong_grandparents;
return TRUE;
/* ERRORS */
no_parent:
{
GST_CAT_DEBUG (GST_CAT_CAPS,
"one of the pads has no parent %" GST_PTR_FORMAT " and %"
GST_PTR_FORMAT, psrc, psink);
return TRUE;
}
no_element_parent:
{
GST_CAT_DEBUG (GST_CAT_CAPS,
"one of the pads has no element parent %" GST_PTR_FORMAT " and %"
GST_PTR_FORMAT, psrc, psink);
return TRUE;
}
same_parents:
{
GST_CAT_DEBUG (GST_CAT_CAPS, "pads have same parent %" GST_PTR_FORMAT,
psrc);
return FALSE;
}
wrong_grandparents:
{
GST_CAT_DEBUG (GST_CAT_CAPS,
"pads have different grandparents %" GST_PTR_FORMAT " and %"
GST_PTR_FORMAT, psrc, psink);
return FALSE;
}
}
/* FIXME leftover from an attempt at refactoring... */
/* call with the two pads unlocked, when this function returns GST_PAD_LINK_OK,
* the two pads will be locked in the srcpad, sinkpad order. */
static GstPadLinkReturn
gst_pad_link_prepare (GstPad * srcpad, GstPad * sinkpad)
{
GST_CAT_INFO (GST_CAT_PADS, "trying to link %s:%s and %s:%s",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
GST_OBJECT_LOCK (srcpad);
if (G_UNLIKELY (GST_PAD_PEER (srcpad) != NULL))
goto src_was_linked;
GST_OBJECT_LOCK (sinkpad);
if (G_UNLIKELY (GST_PAD_PEER (sinkpad) != NULL))
goto sink_was_linked;
/* check hierarchy, pads can only be linked if the grandparents
* are the same. */
if (!gst_pad_link_check_hierarchy (srcpad, sinkpad))
goto wrong_hierarchy;
/* check pad caps for non-empty intersection */
if (!gst_pad_link_check_compatible_unlocked (srcpad, sinkpad))
goto no_format;
/* FIXME check pad scheduling for non-empty intersection */
return GST_PAD_LINK_OK;
src_was_linked:
{
GST_CAT_INFO (GST_CAT_PADS, "src %s:%s was already linked to %s:%s",
GST_DEBUG_PAD_NAME (srcpad),
GST_DEBUG_PAD_NAME (GST_PAD_PEER (srcpad)));
/* we do not emit a warning in this case because unlinking cannot
* be made MT safe.*/
GST_OBJECT_UNLOCK (srcpad);
return GST_PAD_LINK_WAS_LINKED;
}
sink_was_linked:
{
GST_CAT_INFO (GST_CAT_PADS, "sink %s:%s was already linked to %s:%s",
GST_DEBUG_PAD_NAME (sinkpad),
GST_DEBUG_PAD_NAME (GST_PAD_PEER (sinkpad)));
/* we do not emit a warning in this case because unlinking cannot
* be made MT safe.*/
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
return GST_PAD_LINK_WAS_LINKED;
}
wrong_hierarchy:
{
GST_CAT_INFO (GST_CAT_PADS, "pads have wrong hierarchy");
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
return GST_PAD_LINK_WRONG_HIERARCHY;
}
no_format:
{
GST_CAT_INFO (GST_CAT_PADS, "caps are incompatible");
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
return GST_PAD_LINK_NOFORMAT;
}
}
/**
* gst_pad_can_link:
* @srcpad: the source #GstPad.
* @sinkpad: the sink #GstPad.
*
* Checks if the source pad and the sink pad are compatible so they can be
* linked.
*
* Returns: TRUE if the pads can be linked.
*/
gboolean
gst_pad_can_link (GstPad * srcpad, GstPad * sinkpad)
{
GstPadLinkReturn result;
/* generic checks */
g_return_val_if_fail (GST_IS_PAD (srcpad), FALSE);
g_return_val_if_fail (GST_IS_PAD (sinkpad), FALSE);
GST_CAT_INFO (GST_CAT_PADS, "check if %s:%s can link with %s:%s",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
/* gst_pad_link_prepare does everything for us, we only release the locks
* on the pads that it gets us. If this function returns !OK the locks are not
* taken anymore. */
result = gst_pad_link_prepare (srcpad, sinkpad);
if (result != GST_PAD_LINK_OK)
goto done;
GST_OBJECT_UNLOCK (srcpad);
GST_OBJECT_UNLOCK (sinkpad);
done:
return result == GST_PAD_LINK_OK;
}
/**
* gst_pad_link:
* @srcpad: the source #GstPad to link.
* @sinkpad: the sink #GstPad to link.
*
* Links the source pad and the sink pad.
*
* Returns: A result code indicating if the connection worked or
* what went wrong.
*
* MT Safe.
*/
GstPadLinkReturn
gst_pad_link (GstPad * srcpad, GstPad * sinkpad)
{
GstPadLinkReturn result;
GstElement *parent;
g_return_val_if_fail (GST_IS_PAD (srcpad), GST_PAD_LINK_REFUSED);
g_return_val_if_fail (GST_PAD_IS_SRC (srcpad), GST_PAD_LINK_WRONG_DIRECTION);
g_return_val_if_fail (GST_IS_PAD (sinkpad), GST_PAD_LINK_REFUSED);
g_return_val_if_fail (GST_PAD_IS_SINK (sinkpad),
GST_PAD_LINK_WRONG_DIRECTION);
/* Notify the parent early. See gst_pad_unlink for details. */
if ((parent = GST_ELEMENT_CAST (gst_pad_get_parent (srcpad)))) {
if (GST_IS_ELEMENT (parent)) {
gst_element_post_message (parent,
gst_message_new_structure_change (GST_OBJECT_CAST (srcpad),
GST_STRUCTURE_CHANGE_TYPE_PAD_LINK, parent, TRUE));
} else {
gst_object_unref (parent);
parent = NULL;
}
}
/* prepare will also lock the two pads */
result = gst_pad_link_prepare (srcpad, sinkpad);
if (result != GST_PAD_LINK_OK)
goto done;
/* must set peers before calling the link function */
GST_PAD_PEER (srcpad) = sinkpad;
GST_PAD_PEER (sinkpad) = srcpad;
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
/* FIXME released the locks here, concurrent thread might link
* something else. */
if (GST_PAD_LINKFUNC (srcpad)) {
/* this one will call the peer link function */
result = GST_PAD_LINKFUNC (srcpad) (srcpad, sinkpad);
} else if (GST_PAD_LINKFUNC (sinkpad)) {
/* if no source link function, we need to call the sink link
* function ourselves. */
result = GST_PAD_LINKFUNC (sinkpad) (sinkpad, srcpad);
} else {
result = GST_PAD_LINK_OK;
}
GST_OBJECT_LOCK (srcpad);
GST_OBJECT_LOCK (sinkpad);
if (result == GST_PAD_LINK_OK) {
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
/* fire off a signal to each of the pads telling them
* that they've been linked */
g_signal_emit (G_OBJECT (srcpad), gst_pad_signals[PAD_LINKED], 0, sinkpad);
g_signal_emit (G_OBJECT (sinkpad), gst_pad_signals[PAD_LINKED], 0, srcpad);
GST_CAT_INFO (GST_CAT_PADS, "linked %s:%s and %s:%s, successful",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
} else {
GST_CAT_INFO (GST_CAT_PADS, "link between %s:%s and %s:%s failed",
GST_DEBUG_PAD_NAME (srcpad), GST_DEBUG_PAD_NAME (sinkpad));
GST_PAD_PEER (srcpad) = NULL;
GST_PAD_PEER (sinkpad) = NULL;
GST_OBJECT_UNLOCK (sinkpad);
GST_OBJECT_UNLOCK (srcpad);
}
done:
if (parent) {
gst_element_post_message (parent,
gst_message_new_structure_change (GST_OBJECT_CAST (srcpad),
GST_STRUCTURE_CHANGE_TYPE_PAD_LINK, parent, FALSE));
gst_object_unref (parent);
}
return result;
}
static void
gst_pad_set_pad_template (GstPad * pad, GstPadTemplate * templ)
{
GstPadTemplate **template_p;
/* this function would need checks if it weren't static */
GST_OBJECT_LOCK (pad);
template_p = &pad->padtemplate;
gst_object_replace ((GstObject **) template_p, (GstObject *) templ);
GST_OBJECT_UNLOCK (pad);
if (templ)
gst_pad_template_pad_created (templ, pad);
}
/**
* gst_pad_get_pad_template:
* @pad: a #GstPad.
*
* Gets the template for @pad.
*
* Returns: the #GstPadTemplate from which this pad was instantiated, or %NULL
* if this pad has no template.
*
* FIXME: currently returns an unrefcounted padtemplate.
*/
GstPadTemplate *
gst_pad_get_pad_template (GstPad * pad)
{
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
return GST_PAD_PAD_TEMPLATE (pad);
}
/* should be called with the pad LOCK held */
/* refs the caps, so caller is responsible for getting it unreffed */
static GstCaps *
gst_pad_get_caps_unlocked (GstPad * pad)
{
GstCaps *result = NULL;
GstPadTemplate *templ;
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
if (GST_PAD_GETCAPSFUNC (pad)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"dispatching to pad getcaps function");
GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_GETCAPS);
GST_OBJECT_UNLOCK (pad);
result = GST_PAD_GETCAPSFUNC (pad) (pad);
GST_OBJECT_LOCK (pad);
GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_GETCAPS);
if (result == NULL) {
g_critical ("pad %s:%s returned NULL caps from getcaps function",
GST_DEBUG_PAD_NAME (pad));
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"pad getcaps returned %" GST_PTR_FORMAT, result);
#ifndef G_DISABLE_ASSERT
/* check that the returned caps are a real subset of the template caps */
if (GST_PAD_PAD_TEMPLATE (pad)) {
const GstCaps *templ_caps =
GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
if (!gst_caps_is_subset (result, templ_caps)) {
GstCaps *temp;
GST_CAT_ERROR_OBJECT (GST_CAT_CAPS, pad,
"pad returned caps %" GST_PTR_FORMAT
" which are not a real subset of its template caps %"
GST_PTR_FORMAT, result, templ_caps);
g_warning
("pad %s:%s returned caps which are not a real "
"subset of its template caps", GST_DEBUG_PAD_NAME (pad));
temp = gst_caps_intersect (templ_caps, result);
gst_caps_unref (result);
result = temp;
}
}
#endif
goto done;
}
}
if ((templ = GST_PAD_PAD_TEMPLATE (pad))) {
result = GST_PAD_TEMPLATE_CAPS (templ);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"using pad template %p with caps %p %" GST_PTR_FORMAT, templ, result,
result);
result = gst_caps_ref (result);
goto done;
}
if ((result = GST_PAD_CAPS (pad))) {
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"using pad caps %p %" GST_PTR_FORMAT, result, result);
result = gst_caps_ref (result);
goto done;
}
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad has no caps");
result = gst_caps_new_empty ();
done:
return result;
}
/**
* gst_pad_get_caps:
* @pad: a #GstPad to get the capabilities of.
*
* Gets the capabilities this pad can produce or consume.
* Note that this method doesn't necessarily return the caps set by
* gst_pad_set_caps() - use GST_PAD_CAPS() for that instead.
* gst_pad_get_caps returns all possible caps a pad can operate with, using
* the pad's get_caps function;
* this returns the pad template caps if not explicitly set.
*
* Returns: a newly allocated copy of the #GstCaps of this pad.
*
* MT safe.
*/
GstCaps *
gst_pad_get_caps (GstPad * pad)
{
GstCaps *result = NULL;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_OBJECT_LOCK (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get pad caps");
result = gst_pad_get_caps_unlocked (pad);
/* be sure that we have a copy */
if (result)
result = gst_caps_make_writable (result);
GST_OBJECT_UNLOCK (pad);
return result;
}
/**
* gst_pad_peer_get_caps:
* @pad: a #GstPad to get the peer capabilities of.
*
* Gets the capabilities of the peer connected to this pad.
*
* Returns: the #GstCaps of the peer pad. This function returns a new caps, so
* use gst_caps_unref to get rid of it. this function returns NULL if there is
* no peer pad.
*/
GstCaps *
gst_pad_peer_get_caps (GstPad * pad)
{
GstPad *peerpad;
GstCaps *result = NULL;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_OBJECT_LOCK (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "get peer caps");
peerpad = GST_PAD_PEER (pad);
if (G_UNLIKELY (peerpad == NULL))
goto no_peer;
gst_object_ref (peerpad);
GST_OBJECT_UNLOCK (pad);
result = gst_pad_get_caps (peerpad);
gst_object_unref (peerpad);
return result;
no_peer:
{
GST_OBJECT_UNLOCK (pad);
return NULL;
}
}
static gboolean
fixate_value (GValue * dest, const GValue * src)
{
if (G_VALUE_TYPE (src) == GST_TYPE_INT_RANGE) {
g_value_init (dest, G_TYPE_INT);
g_value_set_int (dest, gst_value_get_int_range_min (src));
} else if (G_VALUE_TYPE (src) == GST_TYPE_DOUBLE_RANGE) {
g_value_init (dest, G_TYPE_DOUBLE);
g_value_set_double (dest, gst_value_get_double_range_min (src));
} else if (G_VALUE_TYPE (src) == GST_TYPE_FRACTION_RANGE) {
gst_value_init_and_copy (dest, gst_value_get_fraction_range_min (src));
} else if (G_VALUE_TYPE (src) == GST_TYPE_LIST) {
GValue temp = { 0 };
/* list could be empty */
if (gst_value_list_get_size (src) <= 0)
return FALSE;
gst_value_init_and_copy (&temp, gst_value_list_get_value (src, 0));
if (!fixate_value (dest, &temp))
gst_value_init_and_copy (dest, &temp);
g_value_unset (&temp);
} else if (G_VALUE_TYPE (src) == GST_TYPE_ARRAY) {
gboolean res = FALSE;
guint n;
g_value_init (dest, GST_TYPE_ARRAY);
for (n = 0; n < gst_value_array_get_size (src); n++) {
GValue kid = { 0 };
const GValue *orig_kid = gst_value_array_get_value (src, n);
if (!fixate_value (&kid, orig_kid))
gst_value_init_and_copy (&kid, orig_kid);
else
res = TRUE;
gst_value_array_append_value (dest, &kid);
g_value_unset (&kid);
}
if (!res)
g_value_unset (dest);
return res;
} else {
return FALSE;
}
return TRUE;
}
static gboolean
gst_pad_default_fixate (GQuark field_id, const GValue * value, gpointer data)
{
GstStructure *s = data;
GValue v = { 0 };
if (fixate_value (&v, value)) {
gst_structure_id_set_value (s, field_id, &v);
g_value_unset (&v);
}
return TRUE;
}
/**
* gst_pad_fixate_caps:
* @pad: a #GstPad to fixate
* @caps: the #GstCaps to fixate
*
* Fixate a caps on the given pad. Modifies the caps in place, so you should
* make sure that the caps are actually writable (see gst_caps_make_writable()).
*/
void
gst_pad_fixate_caps (GstPad * pad, GstCaps * caps)
{
GstPadFixateCapsFunction fixatefunc;
guint n;
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (caps != NULL);
if (gst_caps_is_fixed (caps))
return;
fixatefunc = GST_PAD_FIXATECAPSFUNC (pad);
if (fixatefunc) {
fixatefunc (pad, caps);
}
/* default fixation */
for (n = 0; n < gst_caps_get_size (caps); n++) {
GstStructure *s = gst_caps_get_structure (caps, n);
gst_structure_foreach (s, gst_pad_default_fixate, s);
}
}
/* Default accept caps implementation just checks against
* against the allowed caps for the pad */
static gboolean
gst_pad_acceptcaps_default (GstPad * pad, GstCaps * caps)
{
/* get the caps and see if it intersects to something
* not empty */
GstCaps *intersect;
GstCaps *allowed;
gboolean result = FALSE;
GST_DEBUG_OBJECT (pad, "caps %" GST_PTR_FORMAT, caps);
allowed = gst_pad_get_caps (pad);
if (!allowed)
goto nothing_allowed;
GST_DEBUG_OBJECT (pad, "allowed caps %" GST_PTR_FORMAT, allowed);
intersect = gst_caps_intersect (allowed, caps);
GST_DEBUG_OBJECT (pad, "intersection %" GST_PTR_FORMAT, intersect);
result = !gst_caps_is_empty (intersect);
gst_caps_unref (allowed);
gst_caps_unref (intersect);
return result;
/* ERRORS */
nothing_allowed:
{
GST_DEBUG_OBJECT (pad, "no caps allowed on the pad");
return FALSE;
}
}
/**
* gst_pad_accept_caps:
* @pad: a #GstPad to check
* @caps: a #GstCaps to check on the pad
*
* Check if the given pad accepts the caps.
*
* Returns: TRUE if the pad can accept the caps.
*/
gboolean
gst_pad_accept_caps (GstPad * pad, GstCaps * caps)
{
gboolean result;
GstPadAcceptCapsFunction acceptfunc;
GstCaps *existing = NULL;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
/* any pad can be unnegotiated */
if (caps == NULL)
return TRUE;
/* lock for checking the existing caps */
GST_OBJECT_LOCK (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "accept caps of %p", caps);
/* The current caps on a pad are trivially acceptable */
if (G_LIKELY ((existing = GST_PAD_CAPS (pad)))) {
if (caps == existing || gst_caps_is_equal (caps, existing))
goto is_same_caps;
}
acceptfunc = GST_PAD_ACCEPTCAPSFUNC (pad);
GST_OBJECT_UNLOCK (pad);
if (G_LIKELY (acceptfunc)) {
/* we can call the function */
result = acceptfunc (pad, caps);
GST_DEBUG_OBJECT (pad, "acceptfunc returned %d", result);
} else {
/* Only null if the element explicitly unset it */
result = gst_pad_acceptcaps_default (pad, caps);
GST_DEBUG_OBJECT (pad, "default acceptcaps returned %d", result);
}
return result;
is_same_caps:
{
GST_DEBUG_OBJECT (pad, "pad had same caps");
GST_OBJECT_UNLOCK (pad);
return TRUE;
}
}
/**
* gst_pad_peer_accept_caps:
* @pad: a #GstPad to check the peer of
* @caps: a #GstCaps to check on the pad
*
* Check if the peer of @pad accepts @caps. If @pad has no peer, this function
* returns TRUE.
*
* Returns: TRUE if the peer of @pad can accept the caps or @pad has no peer.
*/
gboolean
gst_pad_peer_accept_caps (GstPad * pad, GstCaps * caps)
{
GstPad *peerpad;
gboolean result;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "peer accept caps of (%p)", pad);
peerpad = GST_PAD_PEER (pad);
if (G_UNLIKELY (peerpad == NULL))
goto no_peer;
gst_object_ref (peerpad);
/* release lock before calling external methods but keep ref to pad */
GST_OBJECT_UNLOCK (pad);
result = gst_pad_accept_caps (peerpad, caps);
gst_object_unref (peerpad);
return result;
no_peer:
{
GST_OBJECT_UNLOCK (pad);
return TRUE;
}
}
/**
* gst_pad_set_caps:
* @pad: a #GstPad to set the capabilities of.
* @caps: a #GstCaps to set.
*
* Sets the capabilities of this pad. The caps must be fixed. Any previous
* caps on the pad will be unreffed. This function refs the caps so you should
* unref if as soon as you don't need it anymore.
* It is possible to set NULL caps, which will make the pad unnegotiated
* again.
*
* Returns: TRUE if the caps could be set. FALSE if the caps were not fixed
* or bad parameters were provided to this function.
*
* MT safe.
*/
gboolean
gst_pad_set_caps (GstPad * pad, GstCaps * caps)
{
GstPadSetCapsFunction setcaps;
GstCaps *existing;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (caps == NULL || gst_caps_is_fixed (caps), FALSE);
GST_OBJECT_LOCK (pad);
existing = GST_PAD_CAPS (pad);
if (existing == caps)
goto was_ok;
if (gst_caps_is_equal (caps, existing))
goto setting_same_caps;
setcaps = GST_PAD_SETCAPSFUNC (pad);
/* call setcaps function to configure the pad only if the
* caps is not NULL */
if (setcaps != NULL && caps) {
if (!GST_PAD_IS_IN_SETCAPS (pad)) {
GST_OBJECT_FLAG_SET (pad, GST_PAD_IN_SETCAPS);
GST_OBJECT_UNLOCK (pad);
if (!setcaps (pad, caps))
goto could_not_set;
GST_OBJECT_LOCK (pad);
GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "pad was dispatching");
}
}
gst_caps_replace (&GST_PAD_CAPS (pad), caps);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "caps %" GST_PTR_FORMAT, caps);
GST_OBJECT_UNLOCK (pad);
g_object_notify (G_OBJECT (pad), "caps");
return TRUE;
was_ok:
{
GST_OBJECT_UNLOCK (pad);
return TRUE;
}
setting_same_caps:
{
gst_caps_replace (&GST_PAD_CAPS (pad), caps);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"caps %" GST_PTR_FORMAT " same as existing, updating ptr only", caps);
GST_OBJECT_UNLOCK (pad);
return TRUE;
}
/* ERRORS */
could_not_set:
{
GST_OBJECT_LOCK (pad);
GST_OBJECT_FLAG_UNSET (pad, GST_PAD_IN_SETCAPS);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"caps %" GST_PTR_FORMAT " could not be set", caps);
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
static gboolean
gst_pad_configure_sink (GstPad * pad, GstCaps * caps)
{
gboolean res;
/* See if pad accepts the caps */
if (!gst_pad_accept_caps (pad, caps))
goto not_accepted;
/* set caps on pad if call succeeds */
res = gst_pad_set_caps (pad, caps);
/* no need to unref the caps here, set_caps takes a ref and
* our ref goes away when we leave this function. */
return res;
not_accepted:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"caps %" GST_PTR_FORMAT " not accepted", caps);
return FALSE;
}
}
/* returns TRUE if the src pad could be configured to accept the given caps */
static gboolean
gst_pad_configure_src (GstPad * pad, GstCaps * caps, gboolean dosetcaps)
{
gboolean res;
if (dosetcaps) {
/* See if pad accepts the caps */
if (!gst_pad_accept_caps (pad, caps))
goto not_accepted;
res = gst_pad_set_caps (pad, caps);
} else {
res = TRUE;
}
return res;
not_accepted:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad,
"caps %" GST_PTR_FORMAT " not accepted", caps);
return FALSE;
}
}
/**
* gst_pad_get_pad_template_caps:
* @pad: a #GstPad to get the template capabilities from.
*
* Gets the capabilities for @pad's template.
*
* Returns: the #GstCaps of this pad template. If you intend to keep a
* reference on the caps, make a copy (see gst_caps_copy ()).
*/
const GstCaps *
gst_pad_get_pad_template_caps (GstPad * pad)
{
static GstStaticCaps anycaps = GST_STATIC_CAPS ("ANY");
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
if (GST_PAD_PAD_TEMPLATE (pad))
return GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
return gst_static_caps_get (&anycaps);
}
/**
* gst_pad_get_peer:
* @pad: a #GstPad to get the peer of.
*
* Gets the peer of @pad. This function refs the peer pad so
* you need to unref it after use.
*
* Returns: the peer #GstPad. Unref after usage.
*
* MT safe.
*/
GstPad *
gst_pad_get_peer (GstPad * pad)
{
GstPad *result;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_OBJECT_LOCK (pad);
result = GST_PAD_PEER (pad);
if (result)
gst_object_ref (result);
GST_OBJECT_UNLOCK (pad);
return result;
}
/**
* gst_pad_get_allowed_caps:
* @pad: a #GstPad.
*
* Gets the capabilities of the allowed media types that can flow through
* @pad and its peer.
*
* The allowed capabilities is calculated as the intersection of the results of
* calling gst_pad_get_caps() on @pad and its peer. The caller owns a reference
* on the resulting caps.
*
* Returns: the allowed #GstCaps of the pad link. Unref the caps when you no
* longer need it. This function returns NULL when @pad has no peer.
*
* MT safe.
*/
GstCaps *
gst_pad_get_allowed_caps (GstPad * pad)
{
GstCaps *mycaps;
GstCaps *caps;
GstCaps *peercaps;
GstPad *peer;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_OBJECT_LOCK (pad);
peer = GST_PAD_PEER (pad);
if (G_UNLIKELY (peer == NULL))
goto no_peer;
GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting allowed caps");
gst_object_ref (peer);
GST_OBJECT_UNLOCK (pad);
mycaps = gst_pad_get_caps (pad);
peercaps = gst_pad_get_caps (peer);
gst_object_unref (peer);
caps = gst_caps_intersect (mycaps, peercaps);
gst_caps_unref (peercaps);
gst_caps_unref (mycaps);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "allowed caps %" GST_PTR_FORMAT,
caps);
return caps;
no_peer:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
GST_OBJECT_UNLOCK (pad);
return NULL;
}
}
/**
* gst_pad_get_negotiated_caps:
* @pad: a #GstPad.
*
* Gets the capabilities of the media type that currently flows through @pad
* and its peer.
*
* This function can be used on both src and sinkpads. Note that srcpads are
* always negotiated before sinkpads so it is possible that the negotiated caps
* on the srcpad do not match the negotiated caps of the peer.
*
* Returns: the negotiated #GstCaps of the pad link. Unref the caps when
* you no longer need it. This function returns NULL when the @pad has no
* peer or is not negotiated yet.
*
* MT safe.
*/
GstCaps *
gst_pad_get_negotiated_caps (GstPad * pad)
{
GstCaps *caps;
GstPad *peer;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_OBJECT_LOCK (pad);
if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
goto no_peer;
GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "getting negotiated caps");
caps = GST_PAD_CAPS (pad);
if (caps)
gst_caps_ref (caps);
GST_OBJECT_UNLOCK (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_CAPS, pad, "negotiated caps %" GST_PTR_FORMAT,
caps);
return caps;
no_peer:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PROPERTIES, pad, "no peer");
GST_OBJECT_UNLOCK (pad);
return NULL;
}
}
/* calls the buffer_alloc function on the given pad */
static GstFlowReturn
gst_pad_buffer_alloc_unchecked (GstPad * pad, guint64 offset, gint size,
GstCaps * caps, GstBuffer ** buf)
{
GstFlowReturn ret;
GstPadBufferAllocFunction bufferallocfunc;
GST_OBJECT_LOCK (pad);
/* when the pad is flushing we cannot give a buffer */
if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
goto flushing;
bufferallocfunc = pad->bufferallocfunc;
if (offset == GST_BUFFER_OFFSET_NONE) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"calling bufferallocfunc &%s (@%p) for size %d offset NONE",
GST_DEBUG_FUNCPTR_NAME (bufferallocfunc), bufferallocfunc, size);
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"calling bufferallocfunc &%s (@%p) of for size %d offset %"
G_GUINT64_FORMAT, GST_DEBUG_FUNCPTR_NAME (bufferallocfunc),
bufferallocfunc, size, offset);
}
GST_OBJECT_UNLOCK (pad);
/* G_LIKELY for now since most elements don't implement a buffer alloc
* function and there is no default alloc proxy function as this is usually
* not possible. */
if (G_LIKELY (bufferallocfunc == NULL))
goto fallback;
ret = bufferallocfunc (pad, offset, size, caps, buf);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto error;
/* no error, but NULL buffer means fallback to the default */
if (G_UNLIKELY (*buf == NULL))
goto fallback;
/* If the buffer alloc function didn't set up the caps like it should,
* do it for it */
if (G_UNLIKELY (caps && (GST_BUFFER_CAPS (*buf) == NULL))) {
GST_WARNING_OBJECT (pad,
"Buffer allocation function did not set caps. Setting");
gst_buffer_set_caps (*buf, caps);
}
return ret;
flushing:
{
/* pad was flushing */
GST_OBJECT_UNLOCK (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad was flushing");
return GST_FLOW_WRONG_STATE;
}
error:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"alloc function returned error (%d) %s", ret, gst_flow_get_name (ret));
return ret;
}
fallback:
{
/* fallback case, allocate a buffer of our own, add pad caps. */
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "fallback buffer alloc");
if ((*buf = gst_buffer_try_new_and_alloc (size))) {
GST_BUFFER_OFFSET (*buf) = offset;
gst_buffer_set_caps (*buf, caps);
return GST_FLOW_OK;
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"out of memory allocating %d bytes", size);
return GST_FLOW_ERROR;
}
}
}
/* FIXME 0.11: size should be unsigned */
static GstFlowReturn
gst_pad_alloc_buffer_full (GstPad * pad, guint64 offset, gint size,
GstCaps * caps, GstBuffer ** buf, gboolean setcaps)
{
GstPad *peer;
GstFlowReturn ret;
GstCaps *newcaps;
gboolean caps_changed;
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
g_return_val_if_fail (size >= 0, GST_FLOW_ERROR);
GST_DEBUG_OBJECT (pad, "offset %" G_GUINT64_FORMAT ", size %d, caps %"
GST_PTR_FORMAT, offset, size, caps);
GST_OBJECT_LOCK (pad);
while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
goto flushed;
if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
goto no_peer;
gst_object_ref (peer);
GST_OBJECT_UNLOCK (pad);
ret = gst_pad_buffer_alloc_unchecked (peer, offset, size, caps, buf);
gst_object_unref (peer);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto peer_error;
/* FIXME, move capnego this into a base class? */
newcaps = GST_BUFFER_CAPS (*buf);
/* Lock for checking caps, pretty pointless as the _pad_push() function might
* change it concurrently, one of the problems with automatic caps setting in
* pad_alloc_and_set_caps. Worst case, if does a check too much, but only
* when there is heavy renegotiation going on in both directions. */
GST_OBJECT_LOCK (pad);
caps_changed = newcaps && newcaps != GST_PAD_CAPS (pad);
GST_OBJECT_UNLOCK (pad);
/* we got a new datatype on the pad, see if it can handle it */
if (G_UNLIKELY (caps_changed)) {
GST_DEBUG_OBJECT (pad,
"caps changed from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT,
GST_PAD_CAPS (pad), newcaps, newcaps);
if (G_UNLIKELY (!gst_pad_configure_src (pad, newcaps, setcaps)))
goto not_negotiated;
}
/* sanity check (only if caps are the same) */
if (G_LIKELY (newcaps == caps) && G_UNLIKELY (GST_BUFFER_SIZE (*buf) < size))
goto wrong_size_fallback;
return ret;
flushed:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad, "pad block stopped by flush");
GST_OBJECT_UNLOCK (pad);
return ret;
}
no_peer:
{
/* pad has no peer */
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"called bufferallocfunc but had no peer");
GST_OBJECT_UNLOCK (pad);
return GST_FLOW_NOT_LINKED;
}
peer_error:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"alloc function returned error %s", gst_flow_get_name (ret));
return ret;
}
not_negotiated:
{
gst_buffer_unref (*buf);
*buf = NULL;
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"alloc function returned unacceptable buffer");
return GST_FLOW_NOT_NEGOTIATED;
}
wrong_size_fallback:
{
GST_CAT_ERROR_OBJECT (GST_CAT_PADS, pad, "buffer returned by alloc "
"function is too small (%u < %d), doing fallback buffer alloc",
GST_BUFFER_SIZE (*buf), size);
gst_buffer_unref (*buf);
if ((*buf = gst_buffer_try_new_and_alloc (size))) {
GST_BUFFER_OFFSET (*buf) = offset;
gst_buffer_set_caps (*buf, caps);
return GST_FLOW_OK;
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_PADS, pad,
"out of memory allocating %d bytes", size);
return GST_FLOW_ERROR;
}
}
}
/**
* gst_pad_alloc_buffer:
* @pad: a source #GstPad
* @offset: the offset of the new buffer in the stream
* @size: the size of the new buffer
* @caps: the caps of the new buffer
* @buf: a newly allocated buffer
*
* Allocates a new, empty buffer optimized to push to pad @pad. This
* function only works if @pad is a source pad and has a peer.
*
* A new, empty #GstBuffer will be put in the @buf argument.
* You need to check the caps of the buffer after performing this
* function and renegotiate to the format if needed. If the caps changed, it is
* possible that the buffer returned in @buf is not of the right size for the
* new format, @buf needs to be unreffed and reallocated if this is the case.
*
* Returns: a result code indicating success of the operation. Any
* result code other than #GST_FLOW_OK is an error and @buf should
* not be used.
* An error can occur if the pad is not connected or when the downstream
* peer elements cannot provide an acceptable buffer.
*
* MT safe.
*/
/* FIXME 0.11: size should be unsigned */
GstFlowReturn
gst_pad_alloc_buffer (GstPad * pad, guint64 offset, gint size, GstCaps * caps,
GstBuffer ** buf)
{
return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, FALSE);
}
/**
* gst_pad_alloc_buffer_and_set_caps:
* @pad: a source #GstPad
* @offset: the offset of the new buffer in the stream
* @size: the size of the new buffer
* @caps: the caps of the new buffer
* @buf: a newly allocated buffer
*
* In addition to the function gst_pad_alloc_buffer(), this function
* automatically calls gst_pad_set_caps() when the caps of the
* newly allocated buffer are different from the @pad caps.
*
* After a renegotiation, the size of the new buffer returned in @buf could
* be of the wrong size for the new format and must be unreffed an reallocated
* in that case.
*
* Returns: a result code indicating success of the operation. Any
* result code other than #GST_FLOW_OK is an error and @buf should
* not be used.
* An error can occur if the pad is not connected or when the downstream
* peer elements cannot provide an acceptable buffer.
*
* MT safe.
*/
/* FIXME 0.11: size should be unsigned */
GstFlowReturn
gst_pad_alloc_buffer_and_set_caps (GstPad * pad, guint64 offset, gint size,
GstCaps * caps, GstBuffer ** buf)
{
return gst_pad_alloc_buffer_full (pad, offset, size, caps, buf, TRUE);
}
#ifndef GST_REMOVE_DEPRECATED
typedef struct
{
GList *list;
guint32 cookie;
} IntLinkIterData;
static void
int_link_iter_data_free (IntLinkIterData * data)
{
g_list_free (data->list);
g_free (data);
}
#endif
static GstIteratorItem
iterate_pad (GstIterator * it, GstPad * pad)
{
gst_object_ref (pad);
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_pad_iterate_internal_links_default:
* @pad: the #GstPad to get the internal links of.
*
* Iterate the list of pads to which the given pad is linked to inside of
* the parent element.
* This is the default handler, and thus returns an iterator of all of the
* pads inside the parent element with opposite direction.
*
* The caller must free this iterator after use with gst_iterator_free().
*
* Returns: a #GstIterator of #GstPad, or NULL if @pad has no parent. Unref each
* returned pad with gst_object_unref().
*
* Since: 0.10.21
*/
GstIterator *
gst_pad_iterate_internal_links_default (GstPad * pad)
{
GstIterator *res;
GList **padlist;
guint32 *cookie;
GMutex *lock;
gpointer owner;
GstIteratorDisposeFunction dispose;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
#ifndef GST_REMOVE_DEPRECATED
/* when we get here, the default handler for the iterate links is called,
* which means that the user has not installed a custom one. We first check if
* there is maybe a custom legacy function we can call. */
if (GST_PAD_INTLINKFUNC (pad) &&
GST_PAD_INTLINKFUNC (pad) != gst_pad_get_internal_links_default) {
IntLinkIterData *data;
/* make an iterator for the list. We can't protect the list with a
* cookie. If we would take the cookie of the parent element, we need to
* have a parent, which is not required for GST_PAD_INTLINKFUNC(). We could
* cache the per-pad list and invalidate the list when a new call to
* INTLINKFUNC() returned a different list but then this would only work if
* two concurrent iterators were used and the last iterator would still be
* thread-unsafe. Just don't use this method anymore. */
data = g_new0 (IntLinkIterData, 1);
data->list = GST_PAD_INTLINKFUNC (pad) (pad);
data->cookie = 0;
GST_WARNING_OBJECT (pad, "Making unsafe iterator");
cookie = &data->cookie;
padlist = &data->list;
owner = data;
dispose = (GstIteratorDisposeFunction) int_link_iter_data_free;
/* reuse the pad lock, it's all we have here */
lock = GST_OBJECT_GET_LOCK (pad);
} else
#endif
{
GstElement *parent;
GST_OBJECT_LOCK (pad);
parent = GST_PAD_PARENT (pad);
if (!parent || !GST_IS_ELEMENT (parent))
goto no_parent;
gst_object_ref (parent);
GST_OBJECT_UNLOCK (pad);
if (pad->direction == GST_PAD_SRC)
padlist = &parent->sinkpads;
else
padlist = &parent->srcpads;
GST_DEBUG_OBJECT (pad, "Making iterator");
cookie = &parent->pads_cookie;
owner = parent;
dispose = (GstIteratorDisposeFunction) gst_object_unref;
lock = GST_OBJECT_GET_LOCK (parent);
}
res = gst_iterator_new_list (GST_TYPE_PAD,
lock, cookie, padlist, owner, (GstIteratorItemFunction) iterate_pad,
dispose);
return res;
/* ERRORS */
no_parent:
{
GST_OBJECT_UNLOCK (pad);
GST_DEBUG_OBJECT (pad, "no parent element");
return NULL;
}
}
/**
* gst_pad_iterate_internal_links:
* @pad: the GstPad to get the internal links of.
*
* Gets an iterator for the pads to which the given pad is linked to inside
* of the parent element.
*
* Each #GstPad element yielded by the iterator will have its refcount increased,
* so unref after use.
*
* Returns: a new #GstIterator of #GstPad or %NULL when the pad does not have an
* iterator function configured. Use gst_iterator_free() after usage.
*
* Since: 0.10.21
*/
GstIterator *
gst_pad_iterate_internal_links (GstPad * pad)
{
GstIterator *res = NULL;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
if (GST_PAD_ITERINTLINKFUNC (pad))
res = GST_PAD_ITERINTLINKFUNC (pad) (pad);
return res;
}
#ifndef GST_REMOVE_DEPRECATED
static void
add_unref_pad_to_list (GstPad * pad, GList * list)
{
list = g_list_prepend (list, pad);
gst_object_unref (pad);
}
#endif
/**
* gst_pad_get_internal_links_default:
* @pad: the #GstPad to get the internal links of.
*
* Gets a list of pads to which the given pad is linked to
* inside of the parent element.
* This is the default handler, and thus returns a list of all of the
* pads inside the parent element with opposite direction.
*
* The caller must free this list after use with g_list_free().
*
* Returns: a newly allocated #GList of pads, or NULL if the pad has no parent.
*
* Not MT safe.
*
* Deprecated: This function does not ref the pads in the list so that they
* could become invalid by the time the application accesses them. It's also
* possible that the list changes while handling the pads, which the caller of
* this function is unable to know. Use the thread-safe
* gst_pad_iterate_internal_links_default() instead.
*/
#ifndef GST_REMOVE_DEPRECATED
GList *
gst_pad_get_internal_links_default (GstPad * pad)
{
GList *res = NULL;
GstElement *parent;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_WARNING_OBJECT (pad, "Unsafe internal links used");
/* when we get here, the default handler for get_internal_links is called,
* which means that the user has not installed a custom one. We first check if
* there is maybe a custom iterate function we can call. */
if (GST_PAD_ITERINTLINKFUNC (pad) &&
GST_PAD_ITERINTLINKFUNC (pad) != gst_pad_iterate_internal_links_default) {
GstIterator *it;
GstIteratorResult ires;
gboolean done = FALSE;
it = gst_pad_iterate_internal_links (pad);
/* loop over the iterator and put all elements into a list, we also
* immediatly unref them, which is bad. */
do {
ires = gst_iterator_foreach (it, (GFunc) add_unref_pad_to_list, res);
switch (ires) {
case GST_ITERATOR_OK:
case GST_ITERATOR_DONE:
case GST_ITERATOR_ERROR:
done = TRUE;
break;
case GST_ITERATOR_RESYNC:
/* restart, discard previous list */
gst_iterator_resync (it);
g_list_free (res);
res = NULL;
break;
}
} while (!done);
gst_iterator_free (it);
} else {
/* lock pad, check and ref parent */
GST_OBJECT_LOCK (pad);
parent = GST_PAD_PARENT (pad);
if (!parent || !GST_IS_ELEMENT (parent))
goto no_parent;
parent = gst_object_ref (parent);
GST_OBJECT_UNLOCK (pad);
/* now lock the parent while we copy the pads */
GST_OBJECT_LOCK (parent);
if (pad->direction == GST_PAD_SRC)
res = g_list_copy (parent->sinkpads);
else
res = g_list_copy (parent->srcpads);
GST_OBJECT_UNLOCK (parent);
gst_object_unref (parent);
}
/* At this point pads can be changed and unreffed. Nothing we can do about it
* because for compatibility reasons this function cannot ref the pads or
* notify the app that the list changed. */
return res;
no_parent:
{
GST_DEBUG_OBJECT (pad, "no parent");
GST_OBJECT_UNLOCK (pad);
return NULL;
}
}
#endif /* GST_REMOVE_DEPRECATED */
/**
* gst_pad_get_internal_links:
* @pad: the #GstPad to get the internal links of.
*
* Gets a list of pads to which the given pad is linked to
* inside of the parent element.
* The caller must free this list after use.
*
* Returns: a newly allocated #GList of pads, free with g_list_free().
*
* Not MT safe.
*
* Deprecated: This function does not ref the pads in the list so that they
* could become invalid by the time the application accesses them. It's also
* possible that the list changes while handling the pads, which the caller of
* this function is unable to know. Use the thread-safe
* gst_pad_iterate_internal_links() instead.
*/
#ifndef GST_REMOVE_DEPRECATED
GList *
gst_pad_get_internal_links (GstPad * pad)
{
GList *res = NULL;
g_return_val_if_fail (GST_IS_PAD (pad), NULL);
GST_WARNING_OBJECT (pad, "Calling unsafe internal links");
if (GST_PAD_INTLINKFUNC (pad))
res = GST_PAD_INTLINKFUNC (pad) (pad);
return res;
}
#endif /* GST_REMOVE_DEPRECATED */
static gboolean
gst_pad_event_default_dispatch (GstPad * pad, GstEvent * event)
{
gboolean result = FALSE;
GstIterator *iter;
gboolean done = FALSE;
gpointer item;
GstPad *eventpad;
GList *pushed_pads = NULL;
GST_INFO_OBJECT (pad, "Sending event %p (%s) to all internally linked pads",
event, GST_EVENT_TYPE_NAME (event));
iter = gst_pad_iterate_internal_links (pad);
if (!iter)
goto no_iter;
while (!done) {
switch (gst_iterator_next (iter, &item)) {
case GST_ITERATOR_OK:
eventpad = GST_PAD (item);
/* if already pushed, skip */
if (g_list_find (pushed_pads, eventpad)) {
gst_object_unref (item);
break;
}
if (GST_PAD_IS_SRC (eventpad)) {
/* for each pad we send to, we should ref the event; it's up
* to downstream to unref again when handled. */
GST_LOG_OBJECT (pad, "Reffing and sending event %p (%s) to %s:%s",
event, GST_EVENT_TYPE_NAME (event),
GST_DEBUG_PAD_NAME (eventpad));
gst_event_ref (event);
result |= gst_pad_push_event (eventpad, event);
} else {
/* we only send the event on one pad, multi-sinkpad elements
* should implement a handler */
GST_LOG_OBJECT (pad, "sending event %p (%s) to one sink pad %s:%s",
event, GST_EVENT_TYPE_NAME (event),
GST_DEBUG_PAD_NAME (eventpad));
result = gst_pad_push_event (eventpad, event);
done = TRUE;
event = NULL;
}
pushed_pads = g_list_prepend (pushed_pads, eventpad);
gst_object_unref (item);
break;
case GST_ITERATOR_RESYNC:
/* FIXME, if we want to reset the result value we need to remember which
* pads pushed with which result */
gst_iterator_resync (iter);
break;
case GST_ITERATOR_ERROR:
GST_ERROR_OBJECT (pad, "Could not iterate over internally linked pads");
done = TRUE;
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
no_iter:
/* If this is a sinkpad and we don't have pads to send the event to, we
* return TRUE. This is so that when using the default handler on a sink
* element, we don't fail to push it. */
if (!pushed_pads)
result = GST_PAD_IS_SINK (pad);
g_list_free (pushed_pads);
/* we handled the incoming event so we unref once */
if (event) {
GST_LOG_OBJECT (pad, "handled event %p, unreffing", event);
gst_event_unref (event);
}
return result;
}
/**
* gst_pad_event_default:
* @pad: a #GstPad to call the default event handler on.
* @event: the #GstEvent to handle.
*
* Invokes the default event handler for the given pad. End-of-stream and
* discontinuity events are handled specially, and then the event is sent to all
* pads internally linked to @pad. Note that if there are many possible sink
* pads that are internally linked to @pad, only one will be sent an event.
* Multi-sinkpad elements should implement custom event handlers.
*
* Returns: TRUE if the event was sent succesfully.
*/
gboolean
gst_pad_event_default (GstPad * pad, GstEvent * event)
{
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_EOS:
{
GST_DEBUG_OBJECT (pad, "pausing task because of eos");
gst_pad_pause_task (pad);
}
/* fall thru */
default:
break;
}
return gst_pad_event_default_dispatch (pad, event);
}
/**
* gst_pad_dispatcher:
* @pad: a #GstPad to dispatch.
* @dispatch: the #GstDispatcherFunction to call.
* @data: gpointer user data passed to the dispatcher function.
*
* Invokes the given dispatcher function on each respective peer of
* all pads that are internally linked to the given pad.
* The GstPadDispatcherFunction should return TRUE when no further pads
* need to be processed.
*
* Returns: TRUE if one of the dispatcher functions returned TRUE.
*/
gboolean
gst_pad_dispatcher (GstPad * pad, GstPadDispatcherFunction dispatch,
gpointer data)
{
gboolean res = FALSE;
GstIterator *iter = NULL;
gboolean done = FALSE;
gpointer item;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (dispatch != NULL, FALSE);
iter = gst_pad_iterate_internal_links (pad);
if (!iter)
goto no_iter;
while (!done) {
switch (gst_iterator_next (iter, &item)) {
case GST_ITERATOR_OK:
{
GstPad *int_pad = GST_PAD_CAST (item);
GstPad *int_peer = gst_pad_get_peer (int_pad);
if (int_peer) {
GST_DEBUG_OBJECT (int_pad, "dispatching to peer %s:%s",
GST_DEBUG_PAD_NAME (int_peer));
done = res = dispatch (int_peer, data);
gst_object_unref (int_peer);
} else {
GST_DEBUG_OBJECT (int_pad, "no peer");
}
}
gst_object_unref (item);
break;
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
case GST_ITERATOR_ERROR:
done = TRUE;
GST_ERROR_OBJECT (pad, "Could not iterate internally linked pads");
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
GST_DEBUG_OBJECT (pad, "done, result %d", res);
no_iter:
return res;
}
/**
* gst_pad_query:
* @pad: a #GstPad to invoke the default query on.
* @query: the #GstQuery to perform.
*
* Dispatches a query to a pad. The query should have been allocated by the
* caller via one of the type-specific allocation functions in gstquery.h. The
* element is responsible for filling the query with an appropriate response,
* which should then be parsed with a type-specific query parsing function.
*
* Again, the caller is responsible for both the allocation and deallocation of
* the query structure.
*
* Returns: TRUE if the query could be performed.
*/
gboolean
gst_pad_query (GstPad * pad, GstQuery * query)
{
GstPadQueryFunction func;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
GST_DEBUG_OBJECT (pad, "sending query %p", query);
if ((func = GST_PAD_QUERYFUNC (pad)) == NULL)
goto no_func;
return func (pad, query);
no_func:
{
GST_DEBUG_OBJECT (pad, "had no query function");
return FALSE;
}
}
/**
* gst_pad_peer_query:
* @pad: a #GstPad to invoke the peer query on.
* @query: the #GstQuery to perform.
*
* Performs gst_pad_query() on the peer of @pad.
*
* The caller is responsible for both the allocation and deallocation of
* the query structure.
*
* Returns: TRUE if the query could be performed. This function returns %FALSE
* if @pad has no peer.
*
* Since: 0.10.15
*/
gboolean
gst_pad_peer_query (GstPad * pad, GstQuery * query)
{
GstPad *peerpad;
gboolean result;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
GST_OBJECT_LOCK (pad);
GST_DEBUG_OBJECT (pad, "peer query");
peerpad = GST_PAD_PEER (pad);
if (G_UNLIKELY (peerpad == NULL))
goto no_peer;
gst_object_ref (peerpad);
GST_OBJECT_UNLOCK (pad);
result = gst_pad_query (peerpad, query);
gst_object_unref (peerpad);
return result;
/* ERRORS */
no_peer:
{
GST_WARNING_OBJECT (pad, "pad has no peer");
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_pad_query_default:
* @pad: a #GstPad to call the default query handler on.
* @query: the #GstQuery to handle.
*
* Invokes the default query handler for the given pad.
* The query is sent to all pads internally linked to @pad. Note that
* if there are many possible sink pads that are internally linked to
* @pad, only one will be sent the query.
* Multi-sinkpad elements should implement custom query handlers.
*
* Returns: TRUE if the query was performed succesfully.
*/
gboolean
gst_pad_query_default (GstPad * pad, GstQuery * query)
{
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_POSITION:
case GST_QUERY_SEEKING:
case GST_QUERY_FORMATS:
case GST_QUERY_LATENCY:
case GST_QUERY_JITTER:
case GST_QUERY_RATE:
case GST_QUERY_CONVERT:
default:
return gst_pad_dispatcher
(pad, (GstPadDispatcherFunction) gst_pad_query, query);
}
}
#ifndef GST_DISABLE_LOADSAVE
/* FIXME: why isn't this on a GstElement ? */
/**
* gst_pad_load_and_link:
* @self: an #xmlNodePtr to read the description from.
* @parent: the #GstObject element that owns the pad.
*
* Reads the pad definition from the XML node and links the given pad
* in the element to a pad of an element up in the hierarchy.
*/
void
gst_pad_load_and_link (xmlNodePtr self, GstObject * parent)
{
xmlNodePtr field = self->xmlChildrenNode;
GstPad *pad = NULL, *targetpad;
GstPadTemplate *tmpl;
gchar *peer = NULL;
gchar **split;
GstElement *target;
GstObject *grandparent;
gchar *name = NULL;
while (field) {
if (!strcmp ((char *) field->name, "name")) {
name = (gchar *) xmlNodeGetContent (field);
pad = gst_element_get_static_pad (GST_ELEMENT (parent), name);
if ((!pad) || ((tmpl = gst_pad_get_pad_template (pad))
&& (GST_PAD_REQUEST == GST_PAD_TEMPLATE_PRESENCE (tmpl))))
pad = gst_element_get_request_pad (GST_ELEMENT (parent), name);
g_free (name);
} else if (!strcmp ((char *) field->name, "peer")) {
peer = (gchar *) xmlNodeGetContent (field);
}
field = field->next;
}
g_return_if_fail (pad != NULL);
if (peer == NULL)
return;
split = g_strsplit (peer, ".", 2);
if (split[0] == NULL || split[1] == NULL) {
GST_CAT_DEBUG_OBJECT (GST_CAT_XML, pad,
"Could not parse peer '%s', leaving unlinked", peer);
g_free (peer);
return;
}
g_free (peer);
g_return_if_fail (split[0] != NULL);
g_return_if_fail (split[1] != NULL);
grandparent = gst_object_get_parent (parent);
if (grandparent && GST_IS_BIN (grandparent)) {
target = gst_bin_get_by_name_recurse_up (GST_BIN (grandparent), split[0]);
} else
goto cleanup;
if (target == NULL)
goto cleanup;
targetpad = gst_element_get_static_pad (target, split[1]);
if (!pad)
targetpad = gst_element_get_request_pad (target, split[1]);
if (targetpad == NULL)
goto cleanup;
if (gst_pad_get_direction (pad) == GST_PAD_SRC)
gst_pad_link (pad, targetpad);
else
gst_pad_link (targetpad, pad);
cleanup:
g_strfreev (split);
}
/**
* gst_pad_save_thyself:
* @pad: a #GstPad to save.
* @parent: the parent #xmlNodePtr to save the description in.
*
* Saves the pad into an xml representation.
*
* Returns: the #xmlNodePtr representation of the pad.
*/
static xmlNodePtr
gst_pad_save_thyself (GstObject * object, xmlNodePtr parent)
{
GstPad *pad;
GstPad *peer;
g_return_val_if_fail (GST_IS_PAD (object), NULL);
pad = GST_PAD (object);
xmlNewChild (parent, NULL, (xmlChar *) "name",
(xmlChar *) GST_PAD_NAME (pad));
if (GST_PAD_IS_SRC (pad)) {
xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "source");
} else if (GST_PAD_IS_SINK (pad)) {
xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "sink");
} else {
xmlNewChild (parent, NULL, (xmlChar *) "direction", (xmlChar *) "unknown");
}
if (GST_PAD_PEER (pad) != NULL) {
gchar *content;
peer = GST_PAD_PEER (pad);
/* first check to see if the peer's parent's parent is the same */
/* we just save it off */
content = g_strdup_printf ("%s.%s",
GST_OBJECT_NAME (GST_PAD_PARENT (peer)), GST_PAD_NAME (peer));
xmlNewChild (parent, NULL, (xmlChar *) "peer", (xmlChar *) content);
g_free (content);
} else
xmlNewChild (parent, NULL, (xmlChar *) "peer", NULL);
return parent;
}
#if 0
/**
* gst_ghost_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.
*/
xmlNodePtr
gst_ghost_pad_save_thyself (GstPad * pad, xmlNodePtr parent)
{
xmlNodePtr self;
g_return_val_if_fail (GST_IS_GHOST_PAD (pad), NULL);
self = xmlNewChild (parent, NULL, (xmlChar *) "ghostpad", NULL);
xmlNewChild (self, NULL, (xmlChar *) "name", (xmlChar *) GST_PAD_NAME (pad));
xmlNewChild (self, NULL, (xmlChar *) "parent",
(xmlChar *) GST_OBJECT_NAME (GST_PAD_PARENT (pad)));
/* FIXME FIXME FIXME! */
return self;
}
#endif /* 0 */
#endif /* GST_DISABLE_LOADSAVE */
/*
* should be called with pad OBJECT_LOCK and STREAM_LOCK held.
* GST_PAD_IS_BLOCKED (pad) == TRUE when this function is
* called.
*
* This function performs the pad blocking when an event, buffer push
* or buffer_alloc is performed on a _SRC_ pad. It blocks the
* streaming thread after informing the pad has been blocked.
*
* An application can with this method wait and block any streaming
* thread and perform operations such as seeking or linking.
*
* Two methods are available for notifying the application of the
* block:
* - the callback method, which happens in the STREAMING thread with
* the STREAM_LOCK held. With this method, the most useful way of
* dealing with the callback is to post a message to the main thread
* where the pad block can then be handled outside of the streaming
* thread. With the last method one can perform all operations such
* as doing a state change, linking, unblocking, seeking etc on the
* pad.
* - the GCond signal method, which makes any thread unblock when
* the pad block happens.
*
* During the actual blocking state, the GST_PAD_BLOCKING flag is set.
* The GST_PAD_BLOCKING flag is unset when the pad was unblocked.
*
* MT safe.
*/
static GstFlowReturn
handle_pad_block (GstPad * pad)
{
GstPadBlockCallback callback;
gpointer user_data;
GstFlowReturn ret = GST_FLOW_OK;
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "signal block taken");
/* flushing, don't bother trying to block and return WRONG_STATE
* right away */
if (GST_PAD_IS_FLUSHING (pad))
goto flushingnonref;
/* we grab an extra ref for the callbacks, this is probably not
* needed (callback code does not have a ref and cannot unref). I
* think this was done to make it possible to unref the element in
* the callback, which is in the end totally impossible as it
* requires grabbing the STREAM_LOCK and OBJECT_LOCK which are
* all taken when calling this function. */
gst_object_ref (pad);
while (GST_PAD_IS_BLOCKED (pad)) {
do {
/* we either have a callback installed to notify the block or
* some other thread is doing a GCond wait. */
callback = pad->block_callback;
pad->abidata.ABI.block_callback_called = TRUE;
if (callback) {
/* there is a callback installed, call it. We release the
* lock so that the callback can do something usefull with the
* pad */
user_data = pad->block_data;
GST_OBJECT_UNLOCK (pad);
callback (pad, TRUE, user_data);
GST_OBJECT_LOCK (pad);
/* we released the lock, recheck flushing */
if (GST_PAD_IS_FLUSHING (pad))
goto flushing;
} else {
/* no callback, signal the thread that is doing a GCond wait
* if any. */
GST_PAD_BLOCK_BROADCAST (pad);
}
} while (pad->abidata.ABI.block_callback_called == FALSE
&& GST_PAD_IS_BLOCKED (pad));
/* OBJECT_LOCK could have been released when we did the callback, which
* then could have made the pad unblock so we need to check the blocking
* condition again. */
if (!GST_PAD_IS_BLOCKED (pad))
break;
/* now we block the streaming thread. It can be unlocked when we
* deactivate the pad (which will also set the FLUSHING flag) or
* when the pad is unblocked. A flushing event will also unblock
* the pad after setting the FLUSHING flag. */
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"Waiting to be unblocked or set flushing");
GST_OBJECT_FLAG_SET (pad, GST_PAD_BLOCKING);
GST_PAD_BLOCK_WAIT (pad);
GST_OBJECT_FLAG_UNSET (pad, GST_PAD_BLOCKING);
/* see if we got unblocked by a flush or not */
if (GST_PAD_IS_FLUSHING (pad))
goto flushing;
}
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "got unblocked");
/* when we get here, the pad is unblocked again and we perform
* the needed unblock code. */
callback = pad->block_callback;
if (callback) {
/* we need to call the callback */
user_data = pad->block_data;
GST_OBJECT_UNLOCK (pad);
callback (pad, FALSE, user_data);
GST_OBJECT_LOCK (pad);
} else {
/* we need to signal the thread waiting on the GCond */
GST_PAD_BLOCK_BROADCAST (pad);
}
gst_object_unref (pad);
return ret;
flushingnonref:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad was flushing");
return GST_FLOW_WRONG_STATE;
}
flushing:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad, "pad became flushing");
gst_object_unref (pad);
return GST_FLOW_WRONG_STATE;
}
}
/**********************************************************************
* Data passing functions
*/
static gboolean
gst_pad_emit_have_data_signal (GstPad * pad, GstMiniObject * obj)
{
GValue ret = { 0 };
GValue args[2] = { {0}, {0} };
gboolean res;
GQuark detail;
/* init */
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, TRUE);
g_value_init (&args[0], GST_TYPE_PAD);
g_value_set_object (&args[0], pad);
g_value_init (&args[1], GST_TYPE_MINI_OBJECT);
gst_value_set_mini_object (&args[1], obj);
if (GST_IS_EVENT (obj))
detail = event_quark;
else
detail = buffer_quark;
/* actually emit */
g_signal_emitv (args, gst_pad_signals[PAD_HAVE_DATA], detail, &ret);
res = g_value_get_boolean (&ret);
/* clean up */
g_value_unset (&ret);
g_value_unset (&args[0]);
g_value_unset (&args[1]);
return res;
}
static void
gst_pad_data_unref (gboolean is_buffer, void *data)
{
if (G_LIKELY (is_buffer)) {
gst_buffer_unref (data);
} else {
gst_buffer_list_unref (data);
}
}
static GstCaps *
gst_pad_data_get_caps (gboolean is_buffer, void *data)
{
GstCaps *caps;
if (G_LIKELY (is_buffer)) {
caps = GST_BUFFER_CAPS (data);
} else {
GstBufferListIterator *it;
GstBuffer *buf;
caps = NULL;
it = gst_buffer_list_iterate (GST_BUFFER_LIST_CAST (data));
if (gst_buffer_list_iterator_next_group (it)) {
buf = gst_buffer_list_iterator_next (it);
if (buf != NULL) {
caps = GST_BUFFER_CAPS (buf);
}
}
gst_buffer_list_iterator_free (it);
}
return caps;
}
/* this is the chain function that does not perform the additional argument
* checking for that little extra speed.
*/
static inline GstFlowReturn
gst_pad_chain_data_unchecked (GstPad * pad, gboolean is_buffer, void *data)
{
GstCaps *caps;
gboolean caps_changed;
GstFlowReturn ret;
gboolean emit_signal;
GST_PAD_STREAM_LOCK (pad);
GST_OBJECT_LOCK (pad);
if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
goto flushing;
caps = gst_pad_data_get_caps (is_buffer, data);
caps_changed = caps && caps != GST_PAD_CAPS (pad);
emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
GST_OBJECT_UNLOCK (pad);
/* see if the signal should be emited, we emit before caps nego as
* we might drop the buffer and do capsnego for nothing. */
if (G_UNLIKELY (emit_signal)) {
if (G_LIKELY (is_buffer)) {
if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (data)))
goto dropping;
} else {
/* chain all groups in the buffer list one by one to avoid problems with
* buffer probes that push buffers or events */
goto chain_groups;
}
}
/* we got a new datatype on the pad, see if it can handle it */
if (G_UNLIKELY (caps_changed)) {
GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
goto not_negotiated;
}
/* NOTE: we read the chainfunc unlocked.
* we cannot hold the lock for the pad so we might send
* the data to the wrong function. This is not really a
* problem since functions are assigned at creation time
* and don't change that often... */
if (G_LIKELY (is_buffer)) {
GstPadChainFunction chainfunc;
if (G_UNLIKELY ((chainfunc = GST_PAD_CHAINFUNC (pad)) == NULL))
goto no_function;
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"calling chainfunction &%s", GST_DEBUG_FUNCPTR_NAME (chainfunc));
ret = chainfunc (pad, GST_BUFFER_CAST (data));
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"called chainfunction &%s, returned %s",
GST_DEBUG_FUNCPTR_NAME (chainfunc), gst_flow_get_name (ret));
} else {
GstPadChainListFunction chainlistfunc;
if (G_UNLIKELY ((chainlistfunc = GST_PAD_CHAINLISTFUNC (pad)) == NULL))
goto chain_groups;
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"calling chainlistfunction &%s",
GST_DEBUG_FUNCPTR_NAME (chainlistfunc));
ret = chainlistfunc (pad, GST_BUFFER_LIST_CAST (data));
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"called chainlistfunction &%s, returned %s",
GST_DEBUG_FUNCPTR_NAME (chainlistfunc), gst_flow_get_name (ret));
}
GST_PAD_STREAM_UNLOCK (pad);
return ret;
chain_groups:
{
GstBufferList *list;
GstBufferListIterator *it;
GstBuffer *group;
GST_PAD_STREAM_UNLOCK (pad);
GST_INFO_OBJECT (pad, "chaining each group in list as a merged buffer");
list = GST_BUFFER_LIST_CAST (data);
it = gst_buffer_list_iterate (list);
ret = GST_FLOW_OK;
if (gst_buffer_list_iterator_next_group (it)) {
do {
group = gst_buffer_list_iterator_merge_group (it);
if (group == NULL) {
group = gst_buffer_new ();
GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "chaining empty group");
} else {
GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "chaining group");
}
ret = gst_pad_chain_data_unchecked (pad, TRUE, group);
} while (ret == GST_FLOW_OK && gst_buffer_list_iterator_next_group (it));
} else {
GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "chaining empty group");
ret = gst_pad_chain_data_unchecked (pad, TRUE, gst_buffer_new ());
}
gst_buffer_list_iterator_free (it);
gst_buffer_list_unref (list);
return ret;
}
/* ERRORS */
flushing:
{
gst_pad_data_unref (is_buffer, data);
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pushing, but pad was flushing");
GST_OBJECT_UNLOCK (pad);
GST_PAD_STREAM_UNLOCK (pad);
return GST_FLOW_WRONG_STATE;
}
dropping:
{
gst_pad_data_unref (is_buffer, data);
GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
GST_PAD_STREAM_UNLOCK (pad);
return GST_FLOW_OK;
}
not_negotiated:
{
gst_pad_data_unref (is_buffer, data);
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pushing data but pad did not accept");
GST_PAD_STREAM_UNLOCK (pad);
return GST_FLOW_NOT_NEGOTIATED;
}
no_function:
{
gst_pad_data_unref (is_buffer, data);
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pushing, but not chainhandler");
GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
("push on pad %s:%s but it has no chainfunction",
GST_DEBUG_PAD_NAME (pad)));
GST_PAD_STREAM_UNLOCK (pad);
return GST_FLOW_NOT_SUPPORTED;
}
}
/**
* gst_pad_chain:
* @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
* @buffer: the #GstBuffer to send, return GST_FLOW_ERROR if not.
*
* Chain a buffer to @pad.
*
* The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
*
* If the caps on @buffer are different from the current caps on @pad, this
* function will call any setcaps function (see gst_pad_set_setcaps_function())
* installed on @pad. If the new caps are not acceptable for @pad, this
* function returns #GST_FLOW_NOT_NEGOTIATED.
*
* The function proceeds calling the chain function installed on @pad (see
* gst_pad_set_chain_function()) and the return value of that function is
* returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
* chain function.
*
* In all cases, success or failure, the caller loses its reference to @buffer
* after calling this function.
*
* Returns: a #GstFlowReturn from the pad.
*
* MT safe.
*/
GstFlowReturn
gst_pad_chain (GstPad * pad, GstBuffer * buffer)
{
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SINK (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
return gst_pad_chain_data_unchecked (pad, TRUE, buffer);
}
/**
* gst_pad_chain_list:
* @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
* @list: the #GstBufferList to send, return GST_FLOW_ERROR if not.
*
* Chain a bufferlist to @pad.
*
* The function returns #GST_FLOW_WRONG_STATE if the pad was flushing.
*
* If the caps on the first buffer of @list are different from the current
* caps on @pad, this function will call any setcaps function
* (see gst_pad_set_setcaps_function()) installed on @pad. If the new caps
* are not acceptable for @pad, this function returns #GST_FLOW_NOT_NEGOTIATED.
*
* The function proceeds calling the chainlist function installed on @pad (see
* gst_pad_set_chain_list_function()) and the return value of that function is
* returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if @pad has no
* chainlist function.
*
* In all cases, success or failure, the caller loses its reference to @list
* after calling this function.
*
* Returns: a #GstFlowReturn from the pad.
*
* Since: 0.10.24
*
* MT safe.
*/
GstFlowReturn
gst_pad_chain_list (GstPad * pad, GstBufferList * list)
{
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SINK (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_BUFFER_LIST (list), GST_FLOW_ERROR);
return gst_pad_chain_data_unchecked (pad, FALSE, list);
}
static GstFlowReturn
gst_pad_push_data (GstPad * pad, gboolean is_buffer, void *data)
{
GstPad *peer;
GstFlowReturn ret;
GstCaps *caps;
gboolean caps_changed;
GST_OBJECT_LOCK (pad);
/* FIXME: this check can go away; pad_set_blocked could be implemented with
* probes completely or probes with an extended pad block. */
while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
if ((ret = handle_pad_block (pad)) != GST_FLOW_OK)
goto flushed;
/* we emit signals on the pad arg, the peer will have a chance to
* emit in the _chain() function */
if (G_UNLIKELY (GST_PAD_DO_BUFFER_SIGNALS (pad) > 0)) {
/* unlock before emitting */
GST_OBJECT_UNLOCK (pad);
if (G_LIKELY (is_buffer)) {
/* if the signal handler returned FALSE, it means we should just drop the
* buffer */
if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (data)))
goto dropped;
} else {
/* push all buffers in the list */
goto push_groups;
}
GST_OBJECT_LOCK (pad);
}
if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
goto not_linked;
/* Before pushing the buffer to the peer pad, ensure that caps
* are set on this pad */
caps = gst_pad_data_get_caps (is_buffer, data);
caps_changed = caps && caps != GST_PAD_CAPS (pad);
/* take ref to peer pad before releasing the lock */
gst_object_ref (peer);
GST_OBJECT_UNLOCK (pad);
/* we got a new datatype from the pad, it had better handle it */
if (G_UNLIKELY (caps_changed)) {
GST_DEBUG_OBJECT (pad,
"caps changed from %" GST_PTR_FORMAT " to %p %" GST_PTR_FORMAT,
GST_PAD_CAPS (pad), caps, caps);
if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
goto not_negotiated;
}
ret = gst_pad_chain_data_unchecked (peer, is_buffer, data);
gst_object_unref (peer);
return ret;
push_groups:
{
GstBufferList *list;
GstBufferListIterator *it;
GstBuffer *group;
GST_INFO_OBJECT (pad, "pushing each group in list as a merged buffer");
list = GST_BUFFER_LIST_CAST (data);
it = gst_buffer_list_iterate (list);
ret = GST_FLOW_OK;
if (gst_buffer_list_iterator_next_group (it)) {
do {
group = gst_buffer_list_iterator_merge_group (it);
if (group == NULL) {
group = gst_buffer_new ();
GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "pushing empty group");
} else {
GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "pushing group");
}
ret = gst_pad_push_data (pad, TRUE, group);
} while (ret == GST_FLOW_OK && gst_buffer_list_iterator_next_group (it));
} else {
GST_CAT_INFO_OBJECT (GST_CAT_SCHEDULING, pad, "pushing empty group");
ret = gst_pad_push_data (pad, TRUE, gst_buffer_new ());
}
gst_buffer_list_iterator_free (it);
gst_buffer_list_unref (list);
return ret;
}
/* ERROR recovery here */
flushed:
{
gst_pad_data_unref (is_buffer, data);
GST_DEBUG_OBJECT (pad, "pad block stopped by flush");
GST_OBJECT_UNLOCK (pad);
return ret;
}
dropped:
{
gst_pad_data_unref (is_buffer, data);
GST_DEBUG_OBJECT (pad, "Dropping buffer due to FALSE probe return");
return GST_FLOW_OK;
}
not_linked:
{
gst_pad_data_unref (is_buffer, data);
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pushing, but it was not linked");
GST_OBJECT_UNLOCK (pad);
return GST_FLOW_NOT_LINKED;
}
not_negotiated:
{
gst_pad_data_unref (is_buffer, data);
gst_object_unref (peer);
GST_CAT_DEBUG_OBJECT (GST_CAT_SCHEDULING, pad,
"element pushed data then refused to accept the caps");
return GST_FLOW_NOT_NEGOTIATED;
}
}
/**
* gst_pad_push:
* @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
* @buffer: the #GstBuffer to push returns GST_FLOW_ERROR if not.
*
* Pushes a buffer to the peer of @pad.
*
* This function will call an installed pad block before triggering any
* installed pad probes.
*
* If the caps on @buffer are different from the currently configured caps on
* @pad, this function will call any installed setcaps function on @pad (see
* gst_pad_set_setcaps_function()). In case of failure to renegotiate the new
* format, this function returns #GST_FLOW_NOT_NEGOTIATED.
*
* The function proceeds calling gst_pad_chain() on the peer pad and returns
* the value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will
* be returned.
*
* In all cases, success or failure, the caller loses its reference to @buffer
* after calling this function.
*
* Returns: a #GstFlowReturn from the peer pad.
*
* MT safe.
*/
GstFlowReturn
gst_pad_push (GstPad * pad, GstBuffer * buffer)
{
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_BUFFER (buffer), GST_FLOW_ERROR);
return gst_pad_push_data (pad, TRUE, buffer);
}
/**
* gst_pad_push_list:
* @pad: a source #GstPad, returns #GST_FLOW_ERROR if not.
* @list: the #GstBufferList to push returns GST_FLOW_ERROR if not.
*
* Pushes a buffer list to the peer of @pad.
*
* This function will call an installed pad block before triggering any
* installed pad probes.
*
* If the caps on the first buffer in the first group of @list are different
* from the currently configured caps on @pad, this function will call any
* installed setcaps function on @pad (see gst_pad_set_setcaps_function()). In
* case of failure to renegotiate the new format, this function returns
* #GST_FLOW_NOT_NEGOTIATED.
*
* If there are any probes installed on @pad every group of the buffer list
* will be merged into a normal #GstBuffer and pushed via gst_pad_push and the
* buffer list will be unreffed.
*
* The function proceeds calling the chain function on the peer pad and returns
* the value from that function. If @pad has no peer, #GST_FLOW_NOT_LINKED will
* be returned. If the peer pad does not have any installed chainlist function
* every group buffer of the list will be merged into a normal #GstBuffer and
* chained via gst_pad_chain().
*
* In all cases, success or failure, the caller loses its reference to @list
* after calling this function.
*
* Returns: a #GstFlowReturn from the peer pad.
*
* MT safe.
*
* Since: 0.10.24
*/
GstFlowReturn
gst_pad_push_list (GstPad * pad, GstBufferList * list)
{
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_BUFFER_LIST (list), GST_FLOW_ERROR);
return gst_pad_push_data (pad, FALSE, list);
}
/**
* gst_pad_check_pull_range:
* @pad: a sink #GstPad.
*
* Checks if a gst_pad_pull_range() can be performed on the peer
* source pad. This function is used by plugins that want to check
* if they can use random access on the peer source pad.
*
* The peer sourcepad can implement a custom #GstPadCheckGetRangeFunction
* if it needs to perform some logic to determine if pull_range is
* possible.
*
* Returns: a gboolean with the result.
*
* MT safe.
*/
gboolean
gst_pad_check_pull_range (GstPad * pad)
{
GstPad *peer;
gboolean ret;
GstPadCheckGetRangeFunction checkgetrangefunc;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_OBJECT_LOCK (pad);
if (!GST_PAD_IS_SINK (pad))
goto wrong_direction;
if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
goto not_connected;
gst_object_ref (peer);
GST_OBJECT_UNLOCK (pad);
/* see note in above function */
if (G_LIKELY ((checkgetrangefunc = peer->checkgetrangefunc) == NULL)) {
/* FIXME, kindoff ghetto */
ret = GST_PAD_GETRANGEFUNC (peer) != NULL;
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"no checkgetrangefunc, assuming %d", ret);
} else {
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"calling checkgetrangefunc %s of peer pad %s:%s",
GST_DEBUG_FUNCPTR_NAME (checkgetrangefunc), GST_DEBUG_PAD_NAME (peer));
ret = checkgetrangefunc (peer);
}
gst_object_unref (peer);
return ret;
/* ERROR recovery here */
wrong_direction:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"checking pull range, but pad must be a sinkpad");
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
not_connected:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"checking pull range, but it was not linked");
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_pad_get_range:
* @pad: a src #GstPad, returns #GST_FLOW_ERROR if not.
* @offset: The start offset of the buffer
* @size: The length of the buffer
* @buffer: a pointer to hold the #GstBuffer, returns #GST_FLOW_ERROR if %NULL.
*
* When @pad is flushing this function returns #GST_FLOW_WRONG_STATE
* immediatly.
*
* Calls the getrange function of @pad, see #GstPadGetRangeFunction for a
* description of a getrange function. If @pad has no getrange function
* installed (see gst_pad_set_getrange_function()) this function returns
* #GST_FLOW_NOT_SUPPORTED.
*
* This is a lowlevel function. Usualy gst_pad_pull_range() is used.
*
* Returns: a #GstFlowReturn from the pad.
*
* MT safe.
*/
GstFlowReturn
gst_pad_get_range (GstPad * pad, guint64 offset, guint size,
GstBuffer ** buffer)
{
GstFlowReturn ret;
GstPadGetRangeFunction getrangefunc;
gboolean emit_signal;
GstCaps *caps;
gboolean caps_changed;
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SRC (pad), GST_FLOW_ERROR);
g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
GST_PAD_STREAM_LOCK (pad);
GST_OBJECT_LOCK (pad);
if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
goto flushing;
emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
GST_OBJECT_UNLOCK (pad);
if (G_UNLIKELY ((getrangefunc = GST_PAD_GETRANGEFUNC (pad)) == NULL))
goto no_function;
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"calling getrangefunc %s, offset %"
G_GUINT64_FORMAT ", size %u",
GST_DEBUG_FUNCPTR_NAME (getrangefunc), offset, size);
ret = getrangefunc (pad, offset, size, buffer);
/* can only fire the signal if we have a valid buffer */
if (G_UNLIKELY (emit_signal) && (ret == GST_FLOW_OK)) {
if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
goto dropping;
}
GST_PAD_STREAM_UNLOCK (pad);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto get_range_failed;
GST_OBJECT_LOCK (pad);
/* Before pushing the buffer to the peer pad, ensure that caps
* are set on this pad */
caps = GST_BUFFER_CAPS (*buffer);
caps_changed = caps && caps != GST_PAD_CAPS (pad);
GST_OBJECT_UNLOCK (pad);
if (G_UNLIKELY (caps_changed)) {
GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
/* this should usually work because the element produced the buffer */
if (G_UNLIKELY (!gst_pad_configure_src (pad, caps, TRUE)))
goto not_negotiated;
}
return ret;
/* ERRORS */
flushing:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pulling range, but pad was flushing");
GST_OBJECT_UNLOCK (pad);
GST_PAD_STREAM_UNLOCK (pad);
return GST_FLOW_WRONG_STATE;
}
no_function:
{
GST_ELEMENT_ERROR (GST_PAD_PARENT (pad), CORE, PAD, (NULL),
("pullrange on pad %s:%s but it has no getrangefunction",
GST_DEBUG_PAD_NAME (pad)));
GST_PAD_STREAM_UNLOCK (pad);
return GST_FLOW_NOT_SUPPORTED;
}
dropping:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"Dropping data after FALSE probe return");
GST_PAD_STREAM_UNLOCK (pad);
gst_buffer_unref (*buffer);
*buffer = NULL;
return GST_FLOW_UNEXPECTED;
}
get_range_failed:
{
*buffer = NULL;
GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
"getrange failed %s", gst_flow_get_name (ret));
return ret;
}
not_negotiated:
{
gst_buffer_unref (*buffer);
*buffer = NULL;
GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
"getrange returned buffer of unaccaptable caps");
return GST_FLOW_NOT_NEGOTIATED;
}
}
/**
* gst_pad_pull_range:
* @pad: a sink #GstPad, returns GST_FLOW_ERROR if not.
* @offset: The start offset of the buffer
* @size: The length of the buffer
* @buffer: a pointer to hold the #GstBuffer, returns GST_FLOW_ERROR if %NULL.
*
* Pulls a @buffer from the peer pad.
*
* This function will first trigger the pad block signal if it was
* installed.
*
* When @pad is not linked #GST_FLOW_NOT_LINKED is returned else this
* function returns the result of gst_pad_get_range() on the peer pad.
* See gst_pad_get_range() for a list of return values and for the
* semantics of the arguments of this function.
*
* @buffer's caps must either be unset or the same as what is already
* configured on @pad. Renegotiation within a running pull-mode pipeline is not
* supported.
*
* Returns: a #GstFlowReturn from the peer pad.
* When this function returns #GST_FLOW_OK, @buffer will contain a valid
* #GstBuffer that should be freed with gst_buffer_unref() after usage.
* @buffer may not be used or freed when any other return value than
* #GST_FLOW_OK is returned.
*
* MT safe.
*/
GstFlowReturn
gst_pad_pull_range (GstPad * pad, guint64 offset, guint size,
GstBuffer ** buffer)
{
GstPad *peer;
GstFlowReturn ret;
gboolean emit_signal;
GstCaps *caps;
gboolean caps_changed;
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (GST_PAD_IS_SINK (pad), GST_FLOW_ERROR);
g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
GST_OBJECT_LOCK (pad);
while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad)))
handle_pad_block (pad);
if (G_UNLIKELY ((peer = GST_PAD_PEER (pad)) == NULL))
goto not_connected;
/* signal emision for the pad, peer has chance to emit when
* we call _get_range() */
emit_signal = GST_PAD_DO_BUFFER_SIGNALS (pad) > 0;
gst_object_ref (peer);
GST_OBJECT_UNLOCK (pad);
ret = gst_pad_get_range (peer, offset, size, buffer);
gst_object_unref (peer);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto pull_range_failed;
/* can only fire the signal if we have a valid buffer */
if (G_UNLIKELY (emit_signal)) {
if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (*buffer)))
goto dropping;
}
GST_OBJECT_LOCK (pad);
/* Before pushing the buffer to the peer pad, ensure that caps
* are set on this pad */
caps = GST_BUFFER_CAPS (*buffer);
caps_changed = caps && caps != GST_PAD_CAPS (pad);
GST_OBJECT_UNLOCK (pad);
/* we got a new datatype on the pad, see if it can handle it */
if (G_UNLIKELY (caps_changed)) {
GST_DEBUG_OBJECT (pad, "caps changed to %p %" GST_PTR_FORMAT, caps, caps);
if (G_UNLIKELY (!gst_pad_configure_sink (pad, caps)))
goto not_negotiated;
}
return ret;
/* ERROR recovery here */
not_connected:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"pulling range, but it was not linked");
GST_OBJECT_UNLOCK (pad);
return GST_FLOW_NOT_LINKED;
}
pull_range_failed:
{
*buffer = NULL;
GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
"pullrange failed %s", gst_flow_get_name (ret));
return ret;
}
dropping:
{
GST_CAT_LOG_OBJECT (GST_CAT_SCHEDULING, pad,
"Dropping data after FALSE probe return");
gst_buffer_unref (*buffer);
*buffer = NULL;
return GST_FLOW_UNEXPECTED;
}
not_negotiated:
{
gst_buffer_unref (*buffer);
*buffer = NULL;
GST_CAT_WARNING_OBJECT (GST_CAT_SCHEDULING, pad,
"pullrange returned buffer of different caps");
return GST_FLOW_NOT_NEGOTIATED;
}
}
/**
* gst_pad_push_event:
* @pad: a #GstPad to push the event to.
* @event: the #GstEvent to send to the pad.
*
* Sends the event to the peer of the given pad. This function is
* mainly used by elements to send events to their peer
* elements.
*
* This function takes owership of the provided event so you should
* gst_event_ref() it if you want to reuse the event after this call.
*
* Returns: TRUE if the event was handled.
*
* MT safe.
*/
gboolean
gst_pad_push_event (GstPad * pad, GstEvent * event)
{
GstPad *peerpad;
gboolean result;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
GST_LOG_OBJECT (pad, "event: %s", GST_EVENT_TYPE_NAME (event));
GST_OBJECT_LOCK (pad);
/* Two checks to be made:
* . (un)set the FLUSHING flag for flushing events,
* . handle pad blocking */
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_START:
GST_PAD_SET_FLUSHING (pad);
if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
/* flush start will have set the FLUSHING flag and will then
* unlock all threads doing a GCond wait on the blocking pad. This
* will typically unblock the STREAMING thread blocked on a pad. */
GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-start, "
"doing block signal.");
GST_PAD_BLOCK_BROADCAST (pad);
goto flushed;
}
break;
case GST_EVENT_FLUSH_STOP:
GST_PAD_UNSET_FLUSHING (pad);
/* if we are blocked, flush away the FLUSH_STOP event */
if (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
GST_LOG_OBJECT (pad, "Pad is blocked, not forwarding flush-stop");
goto flushed;
}
break;
default:
while (G_UNLIKELY (GST_PAD_IS_BLOCKED (pad))) {
/* block the event as long as the pad is blocked */
if (handle_pad_block (pad) != GST_FLOW_OK)
goto flushed;
}
break;
}
if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
GST_OBJECT_UNLOCK (pad);
if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT (event)))
goto dropping;
GST_OBJECT_LOCK (pad);
}
peerpad = GST_PAD_PEER (pad);
if (peerpad == NULL)
goto not_linked;
GST_LOG_OBJECT (pad, "sending event %s to peerpad %" GST_PTR_FORMAT,
GST_EVENT_TYPE_NAME (event), peerpad);
gst_object_ref (peerpad);
GST_OBJECT_UNLOCK (pad);
result = gst_pad_send_event (peerpad, event);
/* Note: we gave away ownership of the event at this point */
GST_LOG_OBJECT (pad, "sent event to peerpad %" GST_PTR_FORMAT ", result %d",
peerpad, result);
gst_object_unref (peerpad);
return result;
/* ERROR handling */
dropping:
{
GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
gst_event_unref (event);
return FALSE;
}
not_linked:
{
GST_DEBUG_OBJECT (pad, "Dropping event because pad is not linked");
gst_event_unref (event);
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
flushed:
{
GST_DEBUG_OBJECT (pad,
"Not forwarding event since we're flushing and blocking");
gst_event_unref (event);
GST_OBJECT_UNLOCK (pad);
return TRUE;
}
}
/**
* gst_pad_send_event:
* @pad: a #GstPad to send the event to.
* @event: the #GstEvent to send to the pad.
*
* Sends the event to the pad. This function can be used
* by applications to send events in the pipeline.
*
* If @pad is a source pad, @event should be an upstream event. If @pad is a
* sink pad, @event should be a downstream event. For example, you would not
* send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream.
* Furthermore, some downstream events have to be serialized with data flow,
* like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If
* the event needs to be serialized with data flow, this function will take the
* pad's stream lock while calling its event function.
*
* To find out whether an event type is upstream, downstream, or downstream and
* serialized, see #GstEventTypeFlags, gst_event_type_get_flags(),
* #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and
* #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or
* plugin doesn't need to bother itself with this information; the core handles
* all necessary locks and checks.
*
* This function takes owership of the provided event so you should
* gst_event_ref() it if you want to reuse the event after this call.
*
* Returns: TRUE if the event was handled.
*/
gboolean
gst_pad_send_event (GstPad * pad, GstEvent * event)
{
gboolean result = FALSE;
GstPadEventFunction eventfunc;
gboolean serialized, need_unlock = FALSE;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
GST_OBJECT_LOCK (pad);
if (GST_PAD_IS_SINK (pad)) {
if (G_UNLIKELY (!GST_EVENT_IS_DOWNSTREAM (event)))
goto wrong_direction;
serialized = GST_EVENT_IS_SERIALIZED (event);
} else if (GST_PAD_IS_SRC (pad)) {
if (G_UNLIKELY (!GST_EVENT_IS_UPSTREAM (event)))
goto wrong_direction;
/* events on srcpad never are serialized */
serialized = FALSE;
} else
goto unknown_direction;
if (G_UNLIKELY (GST_EVENT_SRC (event) == NULL)) {
GST_LOG_OBJECT (pad, "event had no source, setting pad as event source");
GST_EVENT_SRC (event) = gst_object_ref (pad);
}
/* pad signals */
if (G_UNLIKELY (GST_PAD_DO_EVENT_SIGNALS (pad) > 0)) {
GST_OBJECT_UNLOCK (pad);
if (!gst_pad_emit_have_data_signal (pad, GST_MINI_OBJECT_CAST (event)))
goto dropping;
GST_OBJECT_LOCK (pad);
}
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_START:
GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad,
"have event type %d (FLUSH_START)", GST_EVENT_TYPE (event));
/* can't even accept a flush begin event when flushing */
if (GST_PAD_IS_FLUSHING (pad))
goto flushing;
GST_PAD_SET_FLUSHING (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "set flush flag");
break;
case GST_EVENT_FLUSH_STOP:
GST_PAD_UNSET_FLUSHING (pad);
GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "cleared flush flag");
GST_OBJECT_UNLOCK (pad);
/* grab stream lock */
GST_PAD_STREAM_LOCK (pad);
need_unlock = TRUE;
GST_OBJECT_LOCK (pad);
break;
default:
GST_CAT_DEBUG_OBJECT (GST_CAT_EVENT, pad, "have event type %s",
GST_EVENT_TYPE_NAME (event));
/* make this a little faster, no point in grabbing the lock
* if the pad is allready flushing. */
if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
goto flushing;
if (serialized) {
/* lock order: STREAM_LOCK, LOCK, recheck flushing. */
GST_OBJECT_UNLOCK (pad);
GST_PAD_STREAM_LOCK (pad);
need_unlock = TRUE;
GST_OBJECT_LOCK (pad);
if (G_UNLIKELY (GST_PAD_IS_FLUSHING (pad)))
goto flushing;
}
break;
}
if (G_UNLIKELY ((eventfunc = GST_PAD_EVENTFUNC (pad)) == NULL))
goto no_function;
GST_OBJECT_UNLOCK (pad);
result = eventfunc (pad, event);
if (need_unlock)
GST_PAD_STREAM_UNLOCK (pad);
GST_DEBUG_OBJECT (pad, "sent event, result %d", result);
return result;
/* ERROR handling */
wrong_direction:
{
g_warning ("pad %s:%s sending %s event in wrong direction",
GST_DEBUG_PAD_NAME (pad), GST_EVENT_TYPE_NAME (event));
GST_OBJECT_UNLOCK (pad);
gst_event_unref (event);
return FALSE;
}
unknown_direction:
{
g_warning ("pad %s:%s has invalid direction", GST_DEBUG_PAD_NAME (pad));
GST_OBJECT_UNLOCK (pad);
gst_event_unref (event);
return FALSE;
}
no_function:
{
g_warning ("pad %s:%s has no event handler, file a bug.",
GST_DEBUG_PAD_NAME (pad));
GST_OBJECT_UNLOCK (pad);
if (need_unlock)
GST_PAD_STREAM_UNLOCK (pad);
gst_event_unref (event);
return FALSE;
}
flushing:
{
GST_OBJECT_UNLOCK (pad);
if (need_unlock)
GST_PAD_STREAM_UNLOCK (pad);
GST_CAT_INFO_OBJECT (GST_CAT_EVENT, pad,
"Received event on flushing pad. Discarding");
gst_event_unref (event);
return FALSE;
}
dropping:
{
GST_DEBUG_OBJECT (pad, "Dropping event after FALSE probe return");
gst_event_unref (event);
return FALSE;
}
}
/**
* gst_pad_set_element_private:
* @pad: the #GstPad to set the private data of.
* @priv: The private data to attach to the pad.
*
* Set the given private data gpointer on the pad.
* This function can only be used by the element that owns the pad.
* No locking is performed in this function.
*/
void
gst_pad_set_element_private (GstPad * pad, gpointer priv)
{
pad->element_private = priv;
}
/**
* gst_pad_get_element_private:
* @pad: the #GstPad to get the private data of.
*
* Gets the private data of a pad.
* No locking is performed in this function.
*
* Returns: a #gpointer to the private data.
*/
gpointer
gst_pad_get_element_private (GstPad * pad)
{
return pad->element_private;
}
static void
do_stream_status (GstPad * pad, GstStreamStatusType type,
GThread * thread, GstTask * task)
{
GstElement *parent;
GST_DEBUG_OBJECT (pad, "doing stream-status %d", type);
if ((parent = GST_ELEMENT_CAST (gst_pad_get_parent (pad)))) {
if (GST_IS_ELEMENT (parent)) {
GstMessage *message;
GValue value = { 0 };
message = gst_message_new_stream_status (GST_OBJECT_CAST (pad),
type, parent);
g_value_init (&value, GST_TYPE_TASK);
g_value_set_object (&value, task);
gst_message_set_stream_status_object (message, &value);
g_value_unset (&value);
GST_DEBUG_OBJECT (pad, "posting stream-status %d", type);
gst_element_post_message (parent, message);
}
gst_object_unref (parent);
}
}
static void
pad_enter_thread (GstTask * task, GThread * thread, gpointer user_data)
{
do_stream_status (GST_PAD_CAST (user_data), GST_STREAM_STATUS_TYPE_ENTER,
thread, task);
}
static void
pad_leave_thread (GstTask * task, GThread * thread, gpointer user_data)
{
do_stream_status (GST_PAD_CAST (user_data), GST_STREAM_STATUS_TYPE_LEAVE,
thread, task);
}
static GstTaskThreadCallbacks thr_callbacks = {
pad_enter_thread,
pad_leave_thread,
};
/**
* gst_pad_start_task:
* @pad: the #GstPad to start the task of
* @func: the task function to call
* @data: data passed to the task function
*
* Starts a task that repeatedly calls @func with @data. This function
* is mostly used in pad activation functions to start the dataflow.
* The #GST_PAD_STREAM_LOCK of @pad will automatically be acquired
* before @func is called.
*
* Returns: a %TRUE if the task could be started.
*/
gboolean
gst_pad_start_task (GstPad * pad, GstTaskFunction func, gpointer data)
{
GstTask *task;
gboolean res;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
g_return_val_if_fail (func != NULL, FALSE);
GST_DEBUG_OBJECT (pad, "start task");
GST_OBJECT_LOCK (pad);
task = GST_PAD_TASK (pad);
if (task == NULL) {
task = gst_task_create (func, data);
gst_task_set_lock (task, GST_PAD_GET_STREAM_LOCK (pad));
gst_task_set_thread_callbacks (task, &thr_callbacks, pad, NULL);
GST_DEBUG_OBJECT (pad, "created task");
/* release lock to post the message */
GST_OBJECT_UNLOCK (pad);
do_stream_status (pad, GST_STREAM_STATUS_TYPE_CREATE, NULL, task);
GST_OBJECT_LOCK (pad);
/* nobody else is supposed to have changed the pad now */
if (GST_PAD_TASK (pad) != NULL)
goto concurrent_start;
GST_PAD_TASK (pad) = task;
}
res = gst_task_set_state (task, GST_TASK_STARTED);
GST_OBJECT_UNLOCK (pad);
return res;
/* ERRORS */
concurrent_start:
{
g_warning ("two threads started pad %s:%s at the same time",
GST_DEBUG_PAD_NAME (pad));
GST_OBJECT_UNLOCK (pad);
gst_object_unref (task);
return FALSE;
}
}
/**
* gst_pad_pause_task:
* @pad: the #GstPad to pause the task of
*
* Pause the task of @pad. This function will also wait until the
* function executed by the task is finished if this function is not
* called from the task function.
*
* Returns: a TRUE if the task could be paused or FALSE when the pad
* has no task.
*/
gboolean
gst_pad_pause_task (GstPad * pad)
{
GstTask *task;
gboolean res;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_DEBUG_OBJECT (pad, "pause task");
GST_OBJECT_LOCK (pad);
task = GST_PAD_TASK (pad);
if (task == NULL)
goto no_task;
res = gst_task_set_state (task, GST_TASK_PAUSED);
GST_OBJECT_UNLOCK (pad);
/* wait for task function to finish, this lock is recursive so it does nothing
* when the pause is called from the task itself */
GST_PAD_STREAM_LOCK (pad);
GST_PAD_STREAM_UNLOCK (pad);
return res;
no_task:
{
GST_DEBUG_OBJECT (pad, "pad has no task");
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_pad_stop_task:
* @pad: the #GstPad to stop the task of
*
* Stop the task of @pad. This function will also make sure that the
* function executed by the task will effectively stop if not called
* from the GstTaskFunction.
*
* This function will deadlock if called from the GstTaskFunction of
* the task. Use gst_task_pause() instead.
*
* Regardless of whether the pad has a task, the stream lock is acquired and
* released so as to ensure that streaming through this pad has finished.
*
* Returns: a TRUE if the task could be stopped or FALSE on error.
*/
gboolean
gst_pad_stop_task (GstPad * pad)
{
GstTask *task;
gboolean res;
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
GST_DEBUG_OBJECT (pad, "stop task");
GST_OBJECT_LOCK (pad);
task = GST_PAD_TASK (pad);
if (task == NULL)
goto no_task;
GST_PAD_TASK (pad) = NULL;
res = gst_task_set_state (task, GST_TASK_STOPPED);
GST_OBJECT_UNLOCK (pad);
GST_PAD_STREAM_LOCK (pad);
GST_PAD_STREAM_UNLOCK (pad);
if (!gst_task_join (task))
goto join_failed;
gst_object_unref (task);
return res;
no_task:
{
GST_DEBUG_OBJECT (pad, "no task");
GST_OBJECT_UNLOCK (pad);
GST_PAD_STREAM_LOCK (pad);
GST_PAD_STREAM_UNLOCK (pad);
/* this is not an error */
return TRUE;
}
join_failed:
{
/* this is bad, possibly the application tried to join the task from
* the task's thread. We install the task again so that it will be stopped
* again from the right thread next time hopefully. */
GST_OBJECT_LOCK (pad);
GST_DEBUG_OBJECT (pad, "join failed");
/* we can only install this task if there was no other task */
if (GST_PAD_TASK (pad) == NULL)
GST_PAD_TASK (pad) = task;
GST_OBJECT_UNLOCK (pad);
return FALSE;
}
}
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