gst/proxy/gstproxysink.c - imx-gst-plugins-bad - Git at Google

 /*
  * 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);
 }
	/*
	* 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);
	}