gstreamer/subprojects/gst-plugins-base/ext/gl/gstglmixerbin.c
Jan Schmidt e1faaefea0 glvideomixer: Implement force-live and min-upstream-latency properties
Proxy the force-live and min-upstream-latency propertyies to the internal
glvideomixerelement at construction time. force-live has to be set
during construction of the glvideomixerelement, so that has to be
deferred until the _constructed() call. Make sure that all other
existing proxied properties will still get set once the element
is created.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4494>
2023-05-02 22:47:38 +00:00

720 lines
22 KiB
C

/*
*
* GStreamer
* Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include "gstglelements.h"
#include "gstglmixerbin.h"
#define GST_CAT_DEFAULT gst_gl_mixer_bin_debug
GST_DEBUG_CATEGORY (gst_gl_mixer_bin_debug);
#define DEFAULT_FORCE_LIVE FALSE
#define DEFAULT_LATENCY 0
#define DEFAULT_START_TIME_SELECTION 0
#define DEFAULT_START_TIME (-1)
#define DEFAULT_MIN_UPSTREAM_LATENCY (0)
typedef enum
{
GST_GL_MIXER_BIN_START_TIME_SELECTION_ZERO,
GST_GL_MIXER_BIN_START_TIME_SELECTION_FIRST,
GST_GL_MIXER_BIN_START_TIME_SELECTION_SET
} GstGLMixerBinStartTimeSelection;
#define GST_TYPE_GL_MIXER_BIN_START_TIME_SELECTION (gst_gl_mixer_bin_start_time_selection_get_type())
static GType
gst_gl_mixer_bin_start_time_selection_get_type (void)
{
static GType gtype = 0;
if (gtype == 0) {
static const GEnumValue values[] = {
{GST_GL_MIXER_BIN_START_TIME_SELECTION_ZERO,
"Start at 0 running time (default)", "zero"},
{GST_GL_MIXER_BIN_START_TIME_SELECTION_FIRST,
"Start at first observed input running time", "first"},
{GST_GL_MIXER_BIN_START_TIME_SELECTION_SET,
"Set start time with start-time property", "set"},
{0, NULL, NULL}
};
gtype = g_enum_register_static ("GstGLMixerBinStartTimeSelection", values);
}
return gtype;
}
struct input_chain
{
GstGLMixerBin *self;
GstGhostPad *ghost_pad;
GstElement *upload;
GstElement *in_convert;
GstElement *in_overlay;
GstPad *mixer_pad;
};
static void
_free_input_chain (struct input_chain *chain)
{
if (!chain)
return;
chain->ghost_pad = NULL;
if (chain->upload) {
gst_element_set_state (chain->upload, GST_STATE_NULL);
gst_bin_remove (GST_BIN (chain->self), chain->upload);
chain->upload = NULL;
}
if (chain->in_convert) {
gst_element_set_state (chain->in_convert, GST_STATE_NULL);
gst_bin_remove (GST_BIN (chain->self), chain->in_convert);
chain->in_convert = NULL;
}
if (chain->in_overlay) {
gst_element_set_state (chain->in_overlay, GST_STATE_NULL);
gst_bin_remove (GST_BIN (chain->self), chain->in_overlay);
chain->in_overlay = NULL;
}
if (chain->mixer_pad) {
gst_element_release_request_pad (chain->self->mixer, chain->mixer_pad);
gst_object_unref (chain->mixer_pad);
chain->mixer_pad = NULL;
}
g_free (chain);
}
struct _GstGLMixerBinPrivate
{
gboolean running;
GList *input_chains;
};
enum
{
PROP_0,
PROP_MIXER,
PROP_LATENCY,
PROP_START_TIME_SELECTION,
PROP_START_TIME,
PROP_CONTEXT,
PROP_FORCE_LIVE,
PROP_MIN_UPSTREAM_LATENCY,
};
enum
{
SIGNAL_0,
SIGNAL_CREATE_ELEMENT,
LAST_SIGNAL
};
static void gst_gl_mixer_bin_child_proxy_init (gpointer g_iface,
gpointer iface_data);
G_DEFINE_TYPE_WITH_CODE (GstGLMixerBin, gst_gl_mixer_bin, GST_TYPE_BIN,
G_ADD_PRIVATE (GstGLMixerBin)
G_IMPLEMENT_INTERFACE (GST_TYPE_CHILD_PROXY,
gst_gl_mixer_bin_child_proxy_init));
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (glmixerbin, "glmixerbin",
GST_RANK_NONE, GST_TYPE_GL_MIXER_BIN, gl_element_init (plugin));
static guint gst_gl_mixer_bin_signals[LAST_SIGNAL] = { 0 };
static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-raw(ANY)")
);
static void gst_gl_mixer_bin_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_gl_mixer_bin_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_gl_mixer_bin_dispose (GObject * object);
static GstPad *gst_gl_mixer_bin_request_new_pad (GstElement * element,
GstPadTemplate * templ, const gchar * req_name, const GstCaps * caps);
static void gst_gl_mixer_bin_release_pad (GstElement * element, GstPad * pad);
static GstStateChangeReturn gst_gl_mixer_bin_change_state (GstElement *
element, GstStateChange transition);
static void
gst_gl_mixer_bin_class_init (GstGLMixerBinClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GstCaps *upload_caps;
GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "glmixerbin", 0,
"opengl mixer bin");
element_class->request_new_pad = gst_gl_mixer_bin_request_new_pad;
element_class->release_pad = gst_gl_mixer_bin_release_pad;
element_class->change_state = gst_gl_mixer_bin_change_state;
gobject_class->get_property = gst_gl_mixer_bin_get_property;
gobject_class->set_property = gst_gl_mixer_bin_set_property;
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_gl_mixer_bin_dispose);
g_object_class_install_property (gobject_class, PROP_MIXER,
g_param_spec_object ("mixer",
"GL mixer element",
"The GL mixer chain to use",
GST_TYPE_ELEMENT,
GST_PARAM_MUTABLE_READY | G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_LATENCY,
g_param_spec_uint64 ("latency", "Buffer latency",
"Additional latency in live mode to allow upstream "
"to take longer to produce buffers for the current "
"position (in nanoseconds)", 0, G_MAXUINT64,
DEFAULT_LATENCY, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_START_TIME_SELECTION,
g_param_spec_enum ("start-time-selection", "Start Time Selection",
"Decides which start time is output",
GST_TYPE_GL_MIXER_BIN_START_TIME_SELECTION,
DEFAULT_START_TIME_SELECTION,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_START_TIME,
g_param_spec_uint64 ("start-time", "Start Time",
"Start time to use if start-time-selection=set", 0,
G_MAXUINT64,
DEFAULT_START_TIME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_CONTEXT,
g_param_spec_object ("context",
"OpenGL context",
"Get OpenGL context",
GST_TYPE_GL_CONTEXT, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
/**
* GstGLMixerBin:force-live:
*
* Causes the element to aggregate on a timeout even when no live source is
* connected to its sinks. See #GstGLMixerBin:min-upstream-latency for a
* companion property: in the vast majority of cases where you plan to plug in
* live sources with a non-zero latency, you should set it to a non-zero value.
*
* Since: 1.24
*/
g_object_class_install_property (gobject_class, PROP_FORCE_LIVE,
g_param_spec_boolean ("force-live",
"Force Live",
"Always operate in live mode and aggregate on timeout regardless of whether any live sources are linked upstream",
DEFAULT_FORCE_LIVE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT_ONLY));
/**
* GstGLMixerBin:min-upstream-latency:
*
* Force minimum upstream latency (in nanoseconds). When sources with a
* higher latency are expected to be plugged in dynamically after the
* aggregator has started playing, this allows overriding the minimum
* latency reported by the initial source(s). This is only taken into
* account when larger than the actually reported minimum latency.
*
* Since: 1.24
*/
g_object_class_install_property (gobject_class, PROP_MIN_UPSTREAM_LATENCY,
g_param_spec_uint64 ("min-upstream-latency", "Buffer latency",
"When sources with a higher latency are expected to be plugged "
"in dynamically after the aggregator has started playing, "
"this allows overriding the minimum latency reported by the "
"initial source(s). This is only taken into account when larger "
"than the actually reported minimum latency. (nanoseconds)",
0, G_MAXUINT64,
DEFAULT_LATENCY, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstMixerBin::create-element:
* @object: the #GstGLMixerBin
*
* Will be emitted when we need the processing element/s that this bin will use
*
* Returns: a new #GstElement
*/
gst_gl_mixer_bin_signals[SIGNAL_CREATE_ELEMENT] =
g_signal_new ("create-element", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, GST_TYPE_ELEMENT, 0);
gst_element_class_add_static_pad_template (element_class, &src_factory);
upload_caps = gst_gl_upload_get_input_template_caps ();
gst_element_class_add_pad_template (element_class,
gst_pad_template_new ("sink_%u", GST_PAD_SINK, GST_PAD_REQUEST,
upload_caps));
gst_caps_unref (upload_caps);
gst_element_class_set_metadata (element_class, "OpenGL video_mixer empty bin",
"Bin/Filter/Effect/Video/Mixer", "OpenGL video_mixer empty bin",
"Matthew Waters <matthew@centricular.com>");
gst_type_mark_as_plugin_api (GST_TYPE_GL_MIXER_BIN_START_TIME_SELECTION, 0);
}
static void
gst_gl_mixer_bin_init (GstGLMixerBin * self)
{
gboolean res = TRUE;
GstPad *pad;
self->priv = gst_gl_mixer_bin_get_instance_private (self);
self->out_convert = gst_element_factory_make ("glcolorconvert", NULL);
self->download = gst_element_factory_make ("gldownload", NULL);
res &= gst_bin_add (GST_BIN (self), self->out_convert);
res &= gst_bin_add (GST_BIN (self), self->download);
res &=
gst_element_link_pads (self->out_convert, "src", self->download, "sink");
pad = gst_element_get_static_pad (self->download, "src");
if (!pad) {
res = FALSE;
} else {
GST_DEBUG_OBJECT (self, "setting target src pad %" GST_PTR_FORMAT, pad);
self->srcpad = gst_ghost_pad_new ("src", pad);
gst_element_add_pad (GST_ELEMENT_CAST (self), self->srcpad);
gst_object_unref (pad);
}
if (!res)
GST_ERROR_OBJECT (self, "failed to create output chain");
self->force_live = DEFAULT_FORCE_LIVE;
self->latency = DEFAULT_LATENCY;
self->start_time_selection = DEFAULT_START_TIME_SELECTION;
self->start_time = DEFAULT_START_TIME;
self->min_upstream_latency = DEFAULT_MIN_UPSTREAM_LATENCY;
}
static void
gst_gl_mixer_bin_dispose (GObject * object)
{
GstGLMixerBin *self = GST_GL_MIXER_BIN (object);
GList *l = self->priv->input_chains;
while (l) {
struct input_chain *chain = l->data;
if (self->mixer && chain->mixer_pad) {
gst_element_release_request_pad (GST_ELEMENT (self->mixer),
chain->mixer_pad);
gst_object_unref (chain->mixer_pad);
chain->mixer_pad = NULL;
}
l = l->next;
}
g_list_free_full (self->priv->input_chains, (GDestroyNotify) g_free);
G_OBJECT_CLASS (gst_gl_mixer_bin_parent_class)->dispose (object);
}
static gboolean
_create_input_chain (GstGLMixerBin * self, struct input_chain *chain,
GstPad * mixer_pad)
{
GstGLMixerBinClass *klass = GST_GL_MIXER_BIN_GET_CLASS (self);
GstPad *pad;
gboolean res = TRUE;
gchar *name;
chain->self = self;
chain->mixer_pad = mixer_pad;
chain->upload = gst_element_factory_make ("glupload", NULL);
chain->in_convert = gst_element_factory_make ("glcolorconvert", NULL);
chain->in_overlay = gst_element_factory_make ("gloverlaycompositor", NULL);
res &= gst_bin_add (GST_BIN (self), chain->in_convert);
res &= gst_bin_add (GST_BIN (self), chain->in_overlay);
res &= gst_bin_add (GST_BIN (self), chain->upload);
if (!res) {
g_warn_if_reached ();
return FALSE;
}
pad = gst_element_get_static_pad (chain->in_overlay, "src");
if (gst_pad_link (pad, mixer_pad) != GST_PAD_LINK_OK) {
gst_object_unref (pad);
return FALSE;
}
gst_object_unref (pad);
if (!gst_element_link_pads (chain->in_convert, "src", chain->in_overlay,
"sink")) {
g_warn_if_reached ();
return FALSE;
}
if (!gst_element_link_pads (chain->upload, "src", chain->in_convert, "sink")) {
g_warn_if_reached ();
return FALSE;
}
pad = gst_element_get_static_pad (chain->upload, "sink");
if (!pad) {
return FALSE;
} else {
GST_DEBUG_OBJECT (self, "setting target sink pad %" GST_PTR_FORMAT, pad);
name = gst_object_get_name (GST_OBJECT (mixer_pad));
if (klass->create_input_pad) {
chain->ghost_pad = klass->create_input_pad (self, chain->mixer_pad);
gst_object_set_name (GST_OBJECT (chain->ghost_pad), name);
gst_ghost_pad_set_target (chain->ghost_pad, pad);
} else {
chain->ghost_pad =
GST_GHOST_PAD (gst_ghost_pad_new (GST_PAD_NAME (chain->mixer_pad),
pad));
}
g_free (name);
GST_OBJECT_LOCK (self);
if (self->priv->running)
gst_pad_set_active (GST_PAD (chain->ghost_pad), TRUE);
GST_OBJECT_UNLOCK (self);
gst_element_add_pad (GST_ELEMENT_CAST (self), GST_PAD (chain->ghost_pad));
gst_object_unref (pad);
}
gst_element_sync_state_with_parent (chain->upload);
gst_element_sync_state_with_parent (chain->in_convert);
gst_element_sync_state_with_parent (chain->in_overlay);
return TRUE;
}
static GstPadTemplate *
_find_element_pad_template (GstElement * element,
GstPadDirection direction, GstPadPresence presence)
{
GstElementClass *klass = GST_ELEMENT_GET_CLASS (element);
GList *templ_list = gst_element_class_get_pad_template_list (klass);
/* find suitable template */
while (templ_list) {
GstPadTemplate *templ = (GstPadTemplate *) templ_list->data;
if (GST_PAD_TEMPLATE_DIRECTION (templ) == direction
&& GST_PAD_TEMPLATE_PRESENCE (templ) == presence) {
return templ;
}
templ_list = templ_list->next;
}
return NULL;
}
static gboolean
_connect_mixer_element (GstGLMixerBin * self)
{
gboolean res = TRUE;
g_return_val_if_fail (self->priv->input_chains == NULL, FALSE);
gst_object_set_name (GST_OBJECT (self->mixer), "mixer");
res &= gst_bin_add (GST_BIN (self), self->mixer);
res &= gst_element_link_pads (self->mixer, "src", self->out_convert, "sink");
if (!res)
GST_ERROR_OBJECT (self, "Failed to link mixer element into the pipeline");
gst_element_sync_state_with_parent (self->mixer);
return res;
}
void
gst_gl_mixer_bin_finish_init_with_element (GstGLMixerBin * self,
GstElement * element)
{
g_return_if_fail (GST_IS_ELEMENT (element));
self->mixer = element;
if (!_connect_mixer_element (self)) {
gst_object_unref (self->mixer);
self->mixer = NULL;
}
}
void
gst_gl_mixer_bin_finish_init (GstGLMixerBin * self)
{
GstGLMixerBinClass *klass = GST_GL_MIXER_BIN_GET_CLASS (self);
GstElement *element = NULL;
if (klass->create_element)
element = klass->create_element ();
if (element)
gst_gl_mixer_bin_finish_init_with_element (self, element);
}
static void
gst_gl_mixer_bin_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstGLMixerBin *self = GST_GL_MIXER_BIN (object);
switch (prop_id) {
case PROP_MIXER:
g_value_set_object (value, self->mixer);
break;
case PROP_FORCE_LIVE:
g_value_set_boolean (value, self->force_live);
break;
default:
if (self->mixer)
g_object_get_property (G_OBJECT (self->mixer), pspec->name, value);
break;
}
}
static void
gst_gl_mixer_bin_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
GstGLMixerBin *self = GST_GL_MIXER_BIN (object);
switch (prop_id) {
case PROP_MIXER:
{
GstElement *mixer = g_value_get_object (value);
/* FIXME: deal with replacing a mixer */
g_return_if_fail (!self->mixer || (self->mixer == mixer));
self->mixer = mixer;
if (mixer) {
gst_object_ref_sink (mixer);
_connect_mixer_element (self);
}
break;
}
case PROP_FORCE_LIVE:
self->force_live = g_value_get_boolean (value);
break;
case PROP_LATENCY:
self->latency = g_value_get_uint64 (value);
if (self->mixer)
g_object_set_property (G_OBJECT (self->mixer), pspec->name, value);
break;
case PROP_START_TIME_SELECTION:
self->start_time_selection = g_value_get_uint (value);
if (self->mixer)
g_object_set_property (G_OBJECT (self->mixer), pspec->name, value);
break;
case PROP_START_TIME:
self->start_time = g_value_get_uint64 (value);
if (self->mixer)
g_object_set_property (G_OBJECT (self->mixer), pspec->name, value);
break;
case PROP_MIN_UPSTREAM_LATENCY:
self->min_upstream_latency = g_value_get_uint64 (value);
if (self->mixer)
g_object_set_property (G_OBJECT (self->mixer), pspec->name, value);
break;
default:
if (self->mixer)
g_object_set_property (G_OBJECT (self->mixer), pspec->name, value);
break;
}
}
static GstPad *
gst_gl_mixer_bin_request_new_pad (GstElement * element, GstPadTemplate * templ,
const gchar * req_name, const GstCaps * caps)
{
GstGLMixerBin *self = GST_GL_MIXER_BIN (element);
GstPadTemplate *mixer_templ;
struct input_chain *chain;
GstPad *mixer_pad;
chain = g_new0 (struct input_chain, 1);
mixer_templ = _find_element_pad_template (self->mixer,
GST_PAD_TEMPLATE_DIRECTION (templ), GST_PAD_TEMPLATE_PRESENCE (templ));
g_return_val_if_fail (mixer_templ, NULL);
mixer_pad =
gst_element_request_pad (self->mixer, mixer_templ, req_name, NULL);
g_return_val_if_fail (mixer_pad, NULL);
if (!_create_input_chain (self, chain, mixer_pad)) {
gst_element_release_request_pad (self->mixer, mixer_pad);
_free_input_chain (chain);
return NULL;
}
GST_OBJECT_LOCK (element);
self->priv->input_chains = g_list_prepend (self->priv->input_chains, chain);
GST_OBJECT_UNLOCK (element);
gst_child_proxy_child_added (GST_CHILD_PROXY (self),
G_OBJECT (chain->ghost_pad), GST_OBJECT_NAME (chain->ghost_pad));
return GST_PAD (chain->ghost_pad);
}
static void
gst_gl_mixer_bin_release_pad (GstElement * element, GstPad * pad)
{
GstGLMixerBin *self = GST_GL_MIXER_BIN (element);
GList *l = self->priv->input_chains;
gboolean released = FALSE;
GST_OBJECT_LOCK (element);
while (l) {
struct input_chain *chain = l->data;
if (GST_PAD (chain->ghost_pad) == pad) {
self->priv->input_chains =
g_list_delete_link (self->priv->input_chains, l);
GST_OBJECT_UNLOCK (element);
_free_input_chain (chain);
gst_element_remove_pad (element, pad);
released = TRUE;
break;
}
l = l->next;
}
if (!released)
GST_OBJECT_UNLOCK (element);
}
static GstStateChangeReturn
gst_gl_mixer_bin_change_state (GstElement * element, GstStateChange transition)
{
GstGLMixerBin *self = GST_GL_MIXER_BIN (element);
GstGLMixerBinClass *klass = GST_GL_MIXER_BIN_GET_CLASS (self);
GstStateChangeReturn ret;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
GST_OBJECT_LOCK (element);
if (!self->mixer) {
if (klass->create_element)
self->mixer = klass->create_element ();
if (!self->mixer)
g_signal_emit (element,
gst_gl_mixer_bin_signals[SIGNAL_CREATE_ELEMENT], 0, &self->mixer);
if (!self->mixer) {
GST_ERROR_OBJECT (element, "Failed to retrieve element");
GST_OBJECT_UNLOCK (element);
return GST_STATE_CHANGE_FAILURE;
}
GST_OBJECT_UNLOCK (element);
if (!_connect_mixer_element (self))
return GST_STATE_CHANGE_FAILURE;
GST_OBJECT_LOCK (element);
}
self->priv->running = TRUE;
GST_OBJECT_UNLOCK (element);
break;
default:
break;
}
ret =
GST_ELEMENT_CLASS (gst_gl_mixer_bin_parent_class)->change_state (element,
transition);
if (ret == GST_STATE_CHANGE_FAILURE)
return ret;
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
GST_OBJECT_LOCK (self);
self->priv->running = FALSE;
GST_OBJECT_UNLOCK (self);
default:
break;
}
return ret;
}
static GObject *
gst_gl_mixer_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
guint index)
{
GstGLMixerBin *mixer = GST_GL_MIXER_BIN (child_proxy);
GstBin *bin = GST_BIN_CAST (child_proxy);
GObject *res = NULL;
GST_OBJECT_LOCK (bin);
/* XXX: not exactly thread safe with ordering */
if (index < bin->numchildren) {
if ((res = g_list_nth_data (bin->children, index)))
gst_object_ref (res);
} else {
struct input_chain *chain;
if ((chain =
g_list_nth_data (mixer->priv->input_chains,
index - bin->numchildren))) {
res = gst_object_ref (chain->ghost_pad);
}
}
GST_OBJECT_UNLOCK (bin);
return res;
}
static guint
gst_gl_mixer_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
{
GstGLMixerBin *mixer = GST_GL_MIXER_BIN (child_proxy);
GstBin *bin = GST_BIN_CAST (child_proxy);
guint num;
GST_OBJECT_LOCK (bin);
num = bin->numchildren + g_list_length (mixer->priv->input_chains);
GST_OBJECT_UNLOCK (bin);
return num;
}
static void
gst_gl_mixer_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
{
GstChildProxyInterface *iface = g_iface;
iface->get_children_count = gst_gl_mixer_bin_child_proxy_get_children_count;
iface->get_child_by_index = gst_gl_mixer_bin_child_proxy_get_child_by_index;
}