gstreamer/gst/proxy/gstproxysink.c

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/*
* Copyright (C) 2018 Centricular Ltd.
* Author: Sebastian Dröge <sebastian@centricular.com>
* Author: Nirbheek Chauhan <nirbheek@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.
*/
/**
* SECTION:element-proxysink
* @title: proxysink
*
* Proxysink is a sink element that proxies events, queries, and buffers to
* another pipeline that contains a matching proxysrc element. The purpose is
* to allow two decoupled pipelines to function as though they are one without
* having to manually shuttle buffers, events, queries, etc between the two.
*
* This element also copies sticky events onto the matching proxysrc element.
*
* For example usage, see proxysrc.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstproxysink.h"
#include "gstproxysrc.h"
#include "gstproxy-priv.h"
#define GST_CAT_DEFAULT gst_proxy_sink_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
/* We're not subclassing from basesink because we don't want any of the special
* handling it has for events/queries/etc. We just pass-through everything. */
/* Unlink proxysrc, we don't contain any elements so our parent is GstElement */
#define parent_class gst_proxy_sink_parent_class
G_DEFINE_TYPE (GstProxySink, gst_proxy_sink, GST_TYPE_ELEMENT);
static gboolean gst_proxy_sink_sink_query (GstPad * pad, GstObject * parent,
GstQuery * query);
static GstFlowReturn gst_proxy_sink_sink_chain (GstPad * pad,
GstObject * parent, GstBuffer * buffer);
static GstFlowReturn gst_proxy_sink_sink_chain_list (GstPad * pad,
GstObject * parent, GstBufferList * list);
static gboolean gst_proxy_sink_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static GstStateChangeReturn gst_proxy_sink_change_state (GstElement * element,
GstStateChange transition);
static void
gst_proxy_sink_class_init (GstProxySinkClass * klass)
{
GstElementClass *gstelement_class = (GstElementClass *) klass;
GST_DEBUG_CATEGORY_INIT (gst_proxy_sink_debug, "proxysink", 0, "proxy sink");
gstelement_class->change_state = gst_proxy_sink_change_state;
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&sink_template));
gst_element_class_set_static_metadata (gstelement_class, "Proxy Sink",
"Sink", "Proxy source for internal process communication",
"Sebastian Dröge <sebastian@centricular.com>");
}
static void
gst_proxy_sink_init (GstProxySink * self)
{
self->sinkpad = gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_proxy_sink_sink_chain));
gst_pad_set_chain_list_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_proxy_sink_sink_chain_list));
gst_pad_set_event_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_proxy_sink_sink_event));
gst_pad_set_query_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_proxy_sink_sink_query));
gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
}
static GstStateChangeReturn
gst_proxy_sink_change_state (GstElement * element, GstStateChange transition)
{
GstElementClass *gstelement_class =
GST_ELEMENT_CLASS (gst_proxy_sink_parent_class);
GstProxySink *self = GST_PROXY_SINK (element);
GstStateChangeReturn ret;
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
self->pending_sticky_events = FALSE;
break;
default:
break;
}
ret = gstelement_class->change_state (element, transition);
return ret;
}
static gboolean
gst_proxy_sink_sink_query (GstPad * pad, GstObject * parent, GstQuery * query)
{
GstProxySink *self = GST_PROXY_SINK (parent);
GstProxySrc *src;
gboolean ret = FALSE;
GST_LOG_OBJECT (pad, "Handling query of type '%s'",
gst_query_type_get_name (GST_QUERY_TYPE (query)));
src = g_weak_ref_get (&self->proxysrc);
if (src) {
GstPad *srcpad;
srcpad = gst_proxy_src_get_internal_srcpad (src);
ret = gst_pad_peer_query (srcpad, query);
gst_object_unref (srcpad);
gst_object_unref (src);
}
return ret;
}
typedef struct
{
GstPad *otherpad;
GstFlowReturn ret;
} CopyStickyEventsData;
static gboolean
copy_sticky_events (G_GNUC_UNUSED GstPad * pad, GstEvent ** event,
gpointer user_data)
{
CopyStickyEventsData *data = user_data;
data->ret = gst_pad_store_sticky_event (data->otherpad, *event);
return data->ret == GST_FLOW_OK;
}
static gboolean
gst_proxy_sink_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstProxySink *self = GST_PROXY_SINK (parent);
GstProxySrc *src;
gboolean ret = FALSE;
gboolean sticky = GST_EVENT_IS_STICKY (event);
GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event));
if (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP)
self->pending_sticky_events = FALSE;
src = g_weak_ref_get (&self->proxysrc);
if (src) {
GstPad *srcpad;
srcpad = gst_proxy_src_get_internal_srcpad (src);
if (sticky && self->pending_sticky_events) {
CopyStickyEventsData data = { srcpad, GST_FLOW_OK };
gst_pad_sticky_events_foreach (pad, copy_sticky_events, &data);
self->pending_sticky_events = data.ret != GST_FLOW_OK;
}
ret = gst_pad_push_event (srcpad, event);
gst_object_unref (srcpad);
gst_object_unref (src);
if (!ret && sticky) {
self->pending_sticky_events = TRUE;
ret = TRUE;
}
} else
gst_event_unref (event);
return ret;
}
static GstFlowReturn
gst_proxy_sink_sink_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
GstProxySink *self = GST_PROXY_SINK (parent);
GstProxySrc *src;
GstFlowReturn ret = GST_FLOW_OK;
GST_LOG_OBJECT (pad, "Chaining buffer %p", buffer);
src = g_weak_ref_get (&self->proxysrc);
if (src) {
GstPad *srcpad;
srcpad = gst_proxy_src_get_internal_srcpad (src);
if (self->pending_sticky_events) {
CopyStickyEventsData data = { srcpad, GST_FLOW_OK };
gst_pad_sticky_events_foreach (pad, copy_sticky_events, &data);
self->pending_sticky_events = data.ret != GST_FLOW_OK;
}
ret = gst_pad_push (srcpad, buffer);
gst_object_unref (srcpad);
gst_object_unref (src);
GST_LOG_OBJECT (pad, "Chained buffer %p: %s", buffer,
gst_flow_get_name (ret));
} else {
gst_buffer_unref (buffer);
GST_LOG_OBJECT (pad, "Dropped buffer %p: no otherpad", buffer);
}
return GST_FLOW_OK;
}
static GstFlowReturn
gst_proxy_sink_sink_chain_list (GstPad * pad, GstObject * parent,
GstBufferList * list)
{
GstProxySink *self = GST_PROXY_SINK (parent);
GstProxySrc *src;
GstFlowReturn ret = GST_FLOW_OK;
GST_LOG_OBJECT (pad, "Chaining buffer list %p", list);
src = g_weak_ref_get (&self->proxysrc);
if (src) {
GstPad *srcpad;
srcpad = gst_proxy_src_get_internal_srcpad (src);
if (self->pending_sticky_events) {
CopyStickyEventsData data = { srcpad, GST_FLOW_OK };
gst_pad_sticky_events_foreach (pad, copy_sticky_events, &data);
self->pending_sticky_events = data.ret != GST_FLOW_OK;
}
ret = gst_pad_push_list (srcpad, list);
gst_object_unref (srcpad);
gst_object_unref (src);
GST_LOG_OBJECT (pad, "Chained buffer list %p: %s", list,
gst_flow_get_name (ret));
} else {
gst_buffer_list_unref (list);
GST_LOG_OBJECT (pad, "Dropped buffer list %p: no otherpad", list);
}
return GST_FLOW_OK;
}
/* Wrapper function for accessing private member
* This can also be retrieved with gst_element_get_static_pad, but that depends
* on the implementation of GstProxySink */
GstPad *
gst_proxy_sink_get_internal_sinkpad (GstProxySink * self)
{
g_return_val_if_fail (self, NULL);
return gst_object_ref (self->sinkpad);
}
void
gst_proxy_sink_set_proxysrc (GstProxySink * self, GstProxySrc * src)
{
g_return_if_fail (self);
g_weak_ref_set (&self->proxysrc, src);
}