libs/gst/base/gstflowcombiner.c - mtk-gstreamer-debian - Git at Google

 /* GStreamer
  *
  * Copyright (C) 2014 Samsung Electronics. All rights reserved.
  *   Author: Thiago Santos <ts.santos@sisa.samsung.com>
  *
  * gstflowcombiner.c: utility to combine multiple flow returns into a single one
  *
  * 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:gstflowcombiner
  * @short_description: Utility to combine multiple flow returns into one
  *
  * Utility struct to help handling #GstFlowReturn combination. Useful for
  * #GstElement<!-- -->s that have multiple source pads and need to combine
  * the different #GstFlowReturn for those pads.
  *
  * #GstFlowCombiner works by using the last #GstFlowReturn for all #GstPad
  * it has in its list and computes the combined return value and provides
  * it to the caller.
  *
  * To add a new pad to the #GstFlowCombiner use gst_flow_combiner_add_pad().
  * The new #GstPad is stored with a default value of %GST_FLOW_OK.
  *
  * In case you want a #GstPad to be removed, use gst_flow_combiner_remove_pad().
  *
  * Please be aware that this struct isn't thread safe as its designed to be
  *  used by demuxers, those usually will have a single thread operating it.
  *
  * These functions will take refs on the passed #GstPad<!-- -->s.
  *
  * Aside from reducing the user's code size, the main advantage of using this
  * helper struct is to follow the standard rules for #GstFlowReturn combination.
  * These rules are:
  *
  * * %GST_FLOW_EOS: only if all returns are EOS too
  * * %GST_FLOW_NOT_LINKED: only if all returns are NOT_LINKED too
  * * %GST_FLOW_ERROR or below: if at least one returns an error return
  * * %GST_FLOW_NOT_NEGOTIATED: if at least one returns a not-negotiated return
  * * %GST_FLOW_FLUSHING: if at least one returns flushing
  * * %GST_FLOW_OK: otherwise
  *
  * %GST_FLOW_ERROR or below, GST_FLOW_NOT_NEGOTIATED and GST_FLOW_FLUSHING are
  * returned immediatelly from the gst_flow_combiner_update_flow() function.
  *
  * Since: 1.4
  */

 #include <gst/gst.h>
 #include "gstflowcombiner.h"

 struct _GstFlowCombiner
 {
   GQueue pads;

   GstFlowReturn last_ret;
   volatile gint ref_count;
 };

 static GstFlowCombiner *gst_flow_combiner_ref (GstFlowCombiner * combiner);
 static void gst_flow_combiner_unref (GstFlowCombiner * combiner);

 G_DEFINE_BOXED_TYPE (GstFlowCombiner, gst_flow_combiner,
     (GBoxedCopyFunc) gst_flow_combiner_ref,
     (GBoxedFreeFunc) gst_flow_combiner_unref);

 /**
  * gst_flow_combiner_new:
  *
  * Creates a new #GstFlowCombiner, use gst_flow_combiner_free() to free it.
  *
  * Returns: A new #GstFlowCombiner
  * Since: 1.4
  */
 GstFlowCombiner *
 gst_flow_combiner_new (void)
 {
   GstFlowCombiner *combiner = g_slice_new (GstFlowCombiner);

   g_queue_init (&combiner->pads);
   combiner->last_ret = GST_FLOW_OK;
   combiner->ref_count = 1;

   return combiner;
 }

 /**
  * gst_flow_combiner_free:
  * @combiner: the #GstFlowCombiner to free
  *
  * Frees a #GstFlowCombiner struct and all its internal data.
  *
  * Since: 1.4
  */
 void
 gst_flow_combiner_free (GstFlowCombiner * combiner)
 {
   gst_flow_combiner_unref (combiner);
 }

 static GstFlowCombiner *
 gst_flow_combiner_ref (GstFlowCombiner * combiner)
 {
   g_return_val_if_fail (combiner != NULL, NULL);

   g_atomic_int_inc (&combiner->ref_count);

   return combiner;
 }

 static void
 gst_flow_combiner_unref (GstFlowCombiner * combiner)
 {
   g_return_if_fail (combiner != NULL);
   g_return_if_fail (combiner->ref_count > 0);

   if (g_atomic_int_dec_and_test (&combiner->ref_count)) {
     GstPad *pad;

     while ((pad = g_queue_pop_head (&combiner->pads)))
       gst_object_unref (pad);

     g_slice_free (GstFlowCombiner, combiner);
   }
 }

 /**
  * gst_flow_combiner_clear:
  * @combiner: the #GstFlowCombiner to clear
  *
  * Removes all pads from a #GstFlowCombiner and resets it to its initial state.
  *
  * Since: 1.6
  */
 void
 gst_flow_combiner_clear (GstFlowCombiner * combiner)
 {
   GstPad *pad;

   g_return_if_fail (combiner != NULL);

   while ((pad = g_queue_pop_head (&combiner->pads)))
     gst_object_unref (pad);
   combiner->last_ret = GST_FLOW_OK;
 }

 /**
  * gst_flow_combiner_reset:
  * @combiner: the #GstFlowCombiner to clear
  *
  * Removes all pads from a #GstFlowCombiner and resets it to its initial state.
  *
  * Since: 1.6
  */
 void
 gst_flow_combiner_reset (GstFlowCombiner * combiner)
 {
   GList *iter;

   g_return_if_fail (combiner != NULL);

   GST_DEBUG ("Reset flow returns");

   for (iter = combiner->pads.head; iter; iter = iter->next) {
     GST_PAD_LAST_FLOW_RETURN (iter->data) = GST_FLOW_OK;
   }

   combiner->last_ret = GST_FLOW_OK;
 }

 static GstFlowReturn
 gst_flow_combiner_get_flow (GstFlowCombiner * combiner)
 {
   GstFlowReturn cret = GST_FLOW_OK;
   gboolean all_eos = TRUE;
   gboolean all_notlinked = TRUE;
   GList *iter;

   GST_DEBUG ("Combining flow returns");

   for (iter = combiner->pads.head; iter; iter = iter->next) {
     GstFlowReturn fret = GST_PAD_LAST_FLOW_RETURN (iter->data);

     if (fret <= GST_FLOW_NOT_NEGOTIATED || fret == GST_FLOW_FLUSHING) {
       GST_DEBUG ("Error flow return found, returning");
       cret = fret;
       goto done;
     }

     if (fret != GST_FLOW_NOT_LINKED) {
       all_notlinked = FALSE;
       if (fret != GST_FLOW_EOS)
         all_eos = FALSE;
     }
   }
   if (all_notlinked)
     cret = GST_FLOW_NOT_LINKED;
   else if (all_eos)
     cret = GST_FLOW_EOS;

 done:
   GST_DEBUG ("Combined flow return: %s (%d)", gst_flow_get_name (cret), cret);
   return cret;
 }

 /**
  * gst_flow_combiner_update_flow:
  * @combiner: the #GstFlowCombiner
  * @fret: the latest #GstFlowReturn received for a pad in this #GstFlowCombiner
  *
  * Computes the combined flow return for the pads in it.
  *
  * The #GstFlowReturn parameter should be the last flow return update for a pad
  * in this #GstFlowCombiner. It will use this value to be able to shortcut some
  * combinations and avoid looking over all pads again. e.g. The last combined
  * return is the same as the latest obtained #GstFlowReturn.
  *
  * Returns: The combined #GstFlowReturn
  * Since: 1.4
  */
 GstFlowReturn
 gst_flow_combiner_update_flow (GstFlowCombiner * combiner, GstFlowReturn fret)
 {
   GstFlowReturn ret;

   g_return_val_if_fail (combiner != NULL, GST_FLOW_ERROR);

   if (combiner->last_ret == fret) {
     return fret;
   }

   if (fret <= GST_FLOW_NOT_NEGOTIATED || fret == GST_FLOW_FLUSHING) {
     ret = fret;
   } else {
     ret = gst_flow_combiner_get_flow (combiner);
   }
   combiner->last_ret = ret;
   return ret;
 }

 /**
  * gst_flow_combiner_update_pad_flow:
  * @combiner: the #GstFlowCombiner
  * @pad: the #GstPad whose #GstFlowReturn to update
  * @fret: the latest #GstFlowReturn received for a pad in this #GstFlowCombiner
  *
  * Sets the provided pad's last flow return to provided value and computes
  * the combined flow return for the pads in it.
  *
  * The #GstFlowReturn parameter should be the last flow return update for a pad
  * in this #GstFlowCombiner. It will use this value to be able to shortcut some
  * combinations and avoid looking over all pads again. e.g. The last combined
  * return is the same as the latest obtained #GstFlowReturn.
  *
  * Returns: The combined #GstFlowReturn
  * Since: 1.6
  */
 GstFlowReturn
 gst_flow_combiner_update_pad_flow (GstFlowCombiner * combiner, GstPad * pad,
     GstFlowReturn fret)
 {
   g_return_val_if_fail (pad != NULL, GST_FLOW_ERROR);

   GST_PAD_LAST_FLOW_RETURN (pad) = fret;

   return gst_flow_combiner_update_flow (combiner, fret);
 }

 /**
  * gst_flow_combiner_add_pad:
  * @combiner: the #GstFlowCombiner
  * @pad: (transfer none): the #GstPad that is being added
  *
  * Adds a new #GstPad to the #GstFlowCombiner.
  *
  * Since: 1.4
  */
 void
 gst_flow_combiner_add_pad (GstFlowCombiner * combiner, GstPad * pad)
 {
   g_return_if_fail (combiner != NULL);
   g_return_if_fail (pad != NULL);

   g_queue_push_head (&combiner->pads, gst_object_ref (pad));
 }

 /**
  * gst_flow_combiner_remove_pad:
  * @combiner: the #GstFlowCombiner
  * @pad: (transfer none): the #GstPad to remove
  *
  * Removes a #GstPad from the #GstFlowCombiner.
  *
  * Since: 1.4
  */
 void
 gst_flow_combiner_remove_pad (GstFlowCombiner * combiner, GstPad * pad)
 {
   g_return_if_fail (combiner != NULL);
   g_return_if_fail (pad != NULL);

   if (g_queue_remove (&combiner->pads, pad))
     gst_object_unref (pad);
 }
	/* GStreamer
	*
	* Copyright (C) 2014 Samsung Electronics. All rights reserved.
	* Author: Thiago Santos <ts.santos@sisa.samsung.com>
	*
	* gstflowcombiner.c: utility to combine multiple flow returns into a single one
	*
	* 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:gstflowcombiner
	* @short_description: Utility to combine multiple flow returns into one
	*
	* Utility struct to help handling #GstFlowReturn combination. Useful for
	* #GstElement<!-- -->s that have multiple source pads and need to combine
	* the different #GstFlowReturn for those pads.
	*
	* #GstFlowCombiner works by using the last #GstFlowReturn for all #GstPad
	* it has in its list and computes the combined return value and provides
	* it to the caller.
	*
	* To add a new pad to the #GstFlowCombiner use gst_flow_combiner_add_pad().
	* The new #GstPad is stored with a default value of %GST_FLOW_OK.
	*
	* In case you want a #GstPad to be removed, use gst_flow_combiner_remove_pad().
	*
	* Please be aware that this struct isn't thread safe as its designed to be
	* used by demuxers, those usually will have a single thread operating it.
	*
	* These functions will take refs on the passed #GstPad<!-- -->s.
	*
	* Aside from reducing the user's code size, the main advantage of using this
	* helper struct is to follow the standard rules for #GstFlowReturn combination.
	* These rules are:
	*
	* * %GST_FLOW_EOS: only if all returns are EOS too
	* * %GST_FLOW_NOT_LINKED: only if all returns are NOT_LINKED too
	* * %GST_FLOW_ERROR or below: if at least one returns an error return
	* * %GST_FLOW_NOT_NEGOTIATED: if at least one returns a not-negotiated return
	* * %GST_FLOW_FLUSHING: if at least one returns flushing
	* * %GST_FLOW_OK: otherwise
	*
	* %GST_FLOW_ERROR or below, GST_FLOW_NOT_NEGOTIATED and GST_FLOW_FLUSHING are
	* returned immediatelly from the gst_flow_combiner_update_flow() function.
	*
	* Since: 1.4
	*/

	#include <gst/gst.h>
	#include "gstflowcombiner.h"

	struct _GstFlowCombiner
	{
	GQueue pads;

	GstFlowReturn last_ret;
	volatile gint ref_count;
	};

	static GstFlowCombiner gst_flow_combiner_ref (GstFlowCombiner combiner);
	static void gst_flow_combiner_unref (GstFlowCombiner * combiner);

	G_DEFINE_BOXED_TYPE (GstFlowCombiner, gst_flow_combiner,
	(GBoxedCopyFunc) gst_flow_combiner_ref,
	(GBoxedFreeFunc) gst_flow_combiner_unref);

	/**
	* gst_flow_combiner_new:
	*
	* Creates a new #GstFlowCombiner, use gst_flow_combiner_free() to free it.
	*
	* Returns: A new #GstFlowCombiner
	* Since: 1.4
	*/
	GstFlowCombiner *
	gst_flow_combiner_new (void)
	{
	GstFlowCombiner *combiner = g_slice_new (GstFlowCombiner);

	g_queue_init (&combiner->pads);
	combiner->last_ret = GST_FLOW_OK;
	combiner->ref_count = 1;

	return combiner;
	}

	/**
	* gst_flow_combiner_free:
	* @combiner: the #GstFlowCombiner to free
	*
	* Frees a #GstFlowCombiner struct and all its internal data.
	*
	* Since: 1.4
	*/
	void
	gst_flow_combiner_free (GstFlowCombiner * combiner)
	{
	gst_flow_combiner_unref (combiner);
	}

	static GstFlowCombiner *
	gst_flow_combiner_ref (GstFlowCombiner * combiner)
	{
	g_return_val_if_fail (combiner != NULL, NULL);

	g_atomic_int_inc (&combiner->ref_count);

	return combiner;
	}

	static void
	gst_flow_combiner_unref (GstFlowCombiner * combiner)
	{
	g_return_if_fail (combiner != NULL);
	g_return_if_fail (combiner->ref_count > 0);

	if (g_atomic_int_dec_and_test (&combiner->ref_count)) {
	GstPad *pad;

	while ((pad = g_queue_pop_head (&combiner->pads)))
	gst_object_unref (pad);

	g_slice_free (GstFlowCombiner, combiner);
	}
	}

	/**
	* gst_flow_combiner_clear:
	* @combiner: the #GstFlowCombiner to clear
	*
	* Removes all pads from a #GstFlowCombiner and resets it to its initial state.
	*
	* Since: 1.6
	*/
	void
	gst_flow_combiner_clear (GstFlowCombiner * combiner)
	{
	GstPad *pad;

	g_return_if_fail (combiner != NULL);

	while ((pad = g_queue_pop_head (&combiner->pads)))
	gst_object_unref (pad);
	combiner->last_ret = GST_FLOW_OK;
	}

	/**
	* gst_flow_combiner_reset:
	* @combiner: the #GstFlowCombiner to clear
	*
	* Removes all pads from a #GstFlowCombiner and resets it to its initial state.
	*
	* Since: 1.6
	*/
	void
	gst_flow_combiner_reset (GstFlowCombiner * combiner)
	{
	GList *iter;

	g_return_if_fail (combiner != NULL);

	GST_DEBUG ("Reset flow returns");

	for (iter = combiner->pads.head; iter; iter = iter->next) {
	GST_PAD_LAST_FLOW_RETURN (iter->data) = GST_FLOW_OK;
	}

	combiner->last_ret = GST_FLOW_OK;
	}

	static GstFlowReturn
	gst_flow_combiner_get_flow (GstFlowCombiner * combiner)
	{
	GstFlowReturn cret = GST_FLOW_OK;
	gboolean all_eos = TRUE;
	gboolean all_notlinked = TRUE;
	GList *iter;

	GST_DEBUG ("Combining flow returns");

	for (iter = combiner->pads.head; iter; iter = iter->next) {
	GstFlowReturn fret = GST_PAD_LAST_FLOW_RETURN (iter->data);

	if (fret <= GST_FLOW_NOT_NEGOTIATED \|\| fret == GST_FLOW_FLUSHING) {
	GST_DEBUG ("Error flow return found, returning");
	cret = fret;
	goto done;
	}

	if (fret != GST_FLOW_NOT_LINKED) {
	all_notlinked = FALSE;
	if (fret != GST_FLOW_EOS)
	all_eos = FALSE;
	}
	}
	if (all_notlinked)
	cret = GST_FLOW_NOT_LINKED;
	else if (all_eos)
	cret = GST_FLOW_EOS;

	done:
	GST_DEBUG ("Combined flow return: %s (%d)", gst_flow_get_name (cret), cret);
	return cret;
	}

	/**
	* gst_flow_combiner_update_flow:
	* @combiner: the #GstFlowCombiner
	* @fret: the latest #GstFlowReturn received for a pad in this #GstFlowCombiner
	*
	* Computes the combined flow return for the pads in it.
	*
	* The #GstFlowReturn parameter should be the last flow return update for a pad
	* in this #GstFlowCombiner. It will use this value to be able to shortcut some
	* combinations and avoid looking over all pads again. e.g. The last combined
	* return is the same as the latest obtained #GstFlowReturn.
	*
	* Returns: The combined #GstFlowReturn
	* Since: 1.4
	*/
	GstFlowReturn
	gst_flow_combiner_update_flow (GstFlowCombiner * combiner, GstFlowReturn fret)
	{
	GstFlowReturn ret;

	g_return_val_if_fail (combiner != NULL, GST_FLOW_ERROR);

	if (combiner->last_ret == fret) {
	return fret;
	}

	if (fret <= GST_FLOW_NOT_NEGOTIATED \|\| fret == GST_FLOW_FLUSHING) {
	ret = fret;
	} else {
	ret = gst_flow_combiner_get_flow (combiner);
	}
	combiner->last_ret = ret;
	return ret;
	}

	/**
	* gst_flow_combiner_update_pad_flow:
	* @combiner: the #GstFlowCombiner
	* @pad: the #GstPad whose #GstFlowReturn to update
	* @fret: the latest #GstFlowReturn received for a pad in this #GstFlowCombiner
	*
	* Sets the provided pad's last flow return to provided value and computes
	* the combined flow return for the pads in it.
	*
	* The #GstFlowReturn parameter should be the last flow return update for a pad
	* in this #GstFlowCombiner. It will use this value to be able to shortcut some
	* combinations and avoid looking over all pads again. e.g. The last combined
	* return is the same as the latest obtained #GstFlowReturn.
	*
	* Returns: The combined #GstFlowReturn
	* Since: 1.6
	*/
	GstFlowReturn
	gst_flow_combiner_update_pad_flow (GstFlowCombiner * combiner, GstPad * pad,
	GstFlowReturn fret)
	{
	g_return_val_if_fail (pad != NULL, GST_FLOW_ERROR);

	GST_PAD_LAST_FLOW_RETURN (pad) = fret;

	return gst_flow_combiner_update_flow (combiner, fret);
	}

	/**
	* gst_flow_combiner_add_pad:
	* @combiner: the #GstFlowCombiner
	* @pad: (transfer none): the #GstPad that is being added
	*
	* Adds a new #GstPad to the #GstFlowCombiner.
	*
	* Since: 1.4
	*/
	void
	gst_flow_combiner_add_pad (GstFlowCombiner * combiner, GstPad * pad)
	{
	g_return_if_fail (combiner != NULL);
	g_return_if_fail (pad != NULL);

	g_queue_push_head (&combiner->pads, gst_object_ref (pad));
	}

	/**
	* gst_flow_combiner_remove_pad:
	* @combiner: the #GstFlowCombiner
	* @pad: (transfer none): the #GstPad to remove
	*
	* Removes a #GstPad from the #GstFlowCombiner.
	*
	* Since: 1.4
	*/
	void
	gst_flow_combiner_remove_pad (GstFlowCombiner * combiner, GstPad * pad)
	{
	g_return_if_fail (combiner != NULL);
	g_return_if_fail (pad != NULL);

	if (g_queue_remove (&combiner->pads, pad))
	gst_object_unref (pad);
	}