gstreamer/gst/autoplug/gststaticautoplug.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gststaticautoplug.c: A static Autoplugger of pipelines
*
* 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.
*/
#include "gststaticautoplug.h"
#include <gst/gst.h>
#define GST_AUTOPLUG_MAX_COST 999999
typedef guint (*GstAutoplugCostFunction) (gpointer src, gpointer dest, gpointer data);
typedef const GList* (*GstAutoplugListFunction) (gpointer data);
static void gst_static_autoplug_class_init (GstStaticAutoplugClass *klass);
static void gst_static_autoplug_init (GstStaticAutoplug *autoplug);
static GList* gst_autoplug_func (gpointer src, gpointer sink,
GstAutoplugListFunction list_function,
GstAutoplugCostFunction cost_function,
gpointer data);
static GstElement* gst_static_autoplug_to_caps (GstAutoplug *autoplug,
GstCaps *srccaps, GstCaps *sinkcaps, va_list args);
static GstAutoplugClass *parent_class = NULL;
GType gst_static_autoplug_get_type(void)
{
static GType static_autoplug_type = 0;
if (!static_autoplug_type) {
static const GTypeInfo static_autoplug_info = {
sizeof(GstElementClass),
NULL,
NULL,
(GClassInitFunc)gst_static_autoplug_class_init,
NULL,
NULL,
sizeof(GstElement),
0,
(GInstanceInitFunc)gst_static_autoplug_init,
};
static_autoplug_type = g_type_register_static (GST_TYPE_AUTOPLUG, "GstStaticAutoplug", &static_autoplug_info, 0);
}
return static_autoplug_type;
}
static void
gst_static_autoplug_class_init(GstStaticAutoplugClass *klass)
{
GstAutoplugClass *gstautoplug_class;
gstautoplug_class = (GstAutoplugClass*) klass;
parent_class = g_type_class_ref(GST_TYPE_AUTOPLUG);
gstautoplug_class->autoplug_to_caps = gst_static_autoplug_to_caps;
}
static void gst_static_autoplug_init(GstStaticAutoplug *autoplug) {
}
static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
GstAutoplugFactory *factory;
gst_plugin_set_longname (plugin, "A static autoplugger");
factory = gst_autoplug_factory_new ("static",
"A static autoplugger, it constructs the complete element before running it",
gst_static_autoplug_get_type ());
if (factory != NULL) {
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
}
return TRUE;
}
GstPluginDesc plugin_desc = {
GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"gststaticautoplug",
plugin_init
};
static gboolean
gst_autoplug_can_match (GstElementFactory *src, GstElementFactory *dest)
{
GList *srctemps, *desttemps;
srctemps = src->padtemplates;
while (srctemps) {
GstPadTemplate *srctemp = (GstPadTemplate *)srctemps->data;
desttemps = dest->padtemplates;
while (desttemps) {
GstPadTemplate *desttemp = (GstPadTemplate *)desttemps->data;
if (srctemp->direction == GST_PAD_SRC &&
desttemp->direction == GST_PAD_SINK) {
if (gst_caps_is_always_compatible (gst_pad_template_get_caps (srctemp),
gst_pad_template_get_caps (desttemp))) {
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT,
"factory \"%s\" can connect with factory \"%s\"\n", GST_OBJECT_NAME (src),
GST_OBJECT_NAME (dest));
return TRUE;
}
}
desttemps = g_list_next (desttemps);
}
srctemps = g_list_next (srctemps);
}
GST_DEBUG (GST_CAT_AUTOPLUG_ATTEMPT,
"factory \"%s\" cannot connect with factory \"%s\"\n", GST_OBJECT_NAME (src),
GST_OBJECT_NAME (dest));
return FALSE;
}
static gboolean
gst_autoplug_pads_autoplug_func (GstElement *src, GstPad *pad, GstElement *sink)
{
const GList *sinkpads;
gboolean connected = FALSE;
GST_DEBUG (0,"gstpipeline: autoplug pad connect function for \"%s\" to \"%s\"",
GST_ELEMENT_NAME(src), GST_ELEMENT_NAME(sink));
sinkpads = gst_element_get_pad_list(sink);
while (sinkpads) {
GstPad *sinkpad = (GstPad *)sinkpads->data;
/* if we have a match, connect the pads */
if (gst_pad_get_direction(sinkpad) == GST_PAD_SINK &&
!GST_PAD_IS_CONNECTED(sinkpad))
{
if (gst_caps_is_always_compatible (gst_pad_get_caps(pad), gst_pad_get_caps(sinkpad))) {
gst_pad_connect(pad, sinkpad);
GST_DEBUG (0,"gstpipeline: autoconnect pad \"%s\" in element %s <-> ", GST_PAD_NAME (pad),
GST_ELEMENT_NAME(src));
GST_DEBUG (0,"pad \"%s\" in element %s", GST_PAD_NAME (sinkpad),
GST_ELEMENT_NAME(sink));
connected = TRUE;
break;
}
else {
GST_DEBUG (0,"pads incompatible %s, %s", GST_PAD_NAME (pad), GST_PAD_NAME (sinkpad));
}
}
sinkpads = g_list_next(sinkpads);
}
if (!connected) {
GST_DEBUG (0,"gstpipeline: no path to sinks for type");
}
return connected;
}
typedef struct {
GstElement *result;
GstCaps *endcap;
gint i;
} dynamic_pad_struct;
static void
autoplug_dynamic_pad (GstElement *element, GstPad *pad, gpointer data)
{
dynamic_pad_struct *info = (dynamic_pad_struct *)data;
const GList *pads = gst_element_get_pad_list (element);
GST_DEBUG (0,"attempting to dynamically create a ghostpad for %s=%s", GST_ELEMENT_NAME (element),
GST_PAD_NAME (pad));
while (pads) {
GstPad *pad = GST_PAD (pads->data);
GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
pads = g_list_next (pads);
if (gst_caps_is_always_compatible (GST_PAD_TEMPLATE_CAPS (templ), info->endcap)) {
gchar *name;
name = g_strdup_printf ("src_%02d", info->i);
gst_element_add_ghost_pad (info->result, pad, name);
g_free (name);
GST_DEBUG (0,"gstpipeline: new dynamic pad %s", GST_PAD_NAME (pad));
break;
}
}
}
static void
gst_autoplug_pads_autoplug (GstElement *src, GstElement *sink)
{
const GList *srcpads;
gboolean connected = FALSE;
srcpads = gst_element_get_pad_list(src);
while (srcpads && !connected) {
GstPad *srcpad = (GstPad *)srcpads->data;
if (gst_pad_get_direction(srcpad) == GST_PAD_SRC)
connected = gst_autoplug_pads_autoplug_func (src, srcpad, sink);
srcpads = g_list_next(srcpads);
}
if (!connected) {
GST_DEBUG (0,"gstpipeline: delaying pad connections for \"%s\" to \"%s\"",
GST_ELEMENT_NAME(src), GST_ELEMENT_NAME(sink));
g_signal_connect (G_OBJECT(src), "new_pad",
G_CALLBACK (gst_autoplug_pads_autoplug_func), sink);
}
}
static const GList*
gst_autoplug_element_factory_get_list (gpointer data)
{
return gst_registry_pool_feature_list (GST_TYPE_ELEMENT_FACTORY);
}
typedef struct {
GstCaps *src;
GstCaps *sink;
} caps_struct;
#define IS_CAPS(cap) (((cap) == caps->src) || (cap) == caps->sink)
static guint
gst_autoplug_caps_find_cost (gpointer src, gpointer dest, gpointer data)
{
caps_struct *caps = (caps_struct *)data;
gboolean res;
if (IS_CAPS (src) && IS_CAPS (dest)) {
res = gst_caps_is_always_compatible ((GstCaps *)src, (GstCaps *)dest);
}
else if (IS_CAPS (src)) {
res = gst_element_factory_can_sink_caps ((GstElementFactory *)dest, (GstCaps *)src);
}
else if (IS_CAPS (dest)) {
res = gst_element_factory_can_src_caps ((GstElementFactory *)src, (GstCaps *)dest);
}
else {
res = gst_autoplug_can_match ((GstElementFactory *)src, (GstElementFactory *)dest);
}
if (res)
return 1;
else
return GST_AUTOPLUG_MAX_COST;
}
static GstElement*
gst_static_autoplug_to_caps (GstAutoplug *autoplug, GstCaps *srccaps, GstCaps *sinkcaps, va_list args)
{
caps_struct caps;
GstCaps *capslist;
GstElement *result = NULL, *srcelement = NULL;
GList **factories;
GList *chains = NULL;
GList *endcaps = NULL;
guint numsinks = 0, i;
gboolean have_common = FALSE;
capslist = sinkcaps;
/*
* We first create a list of elements that are needed
* to convert the srcpad caps to the different sinkpad caps.
* and add the list of elementfactories to a list (chains).
*/
caps.src = srccaps;
while (capslist) {
GList *elements;
caps.sink = capslist;
GST_INFO (GST_CAT_AUTOPLUG_ATTEMPT,"autoplugging two caps structures");
elements = gst_autoplug_func (caps.src, caps.sink,
gst_autoplug_element_factory_get_list,
gst_autoplug_caps_find_cost,
&caps);
if (elements) {
chains = g_list_append (chains, elements);
endcaps = g_list_append (endcaps, capslist);
numsinks++;
}
else {
}
capslist = va_arg (args, GstCaps *);
}
/*
* If no list could be found the pipeline cannot be autoplugged and
* we return a NULL element
*/
if (numsinks == 0)
return NULL;
/*
* We now have a list of lists. We will turn this into an array
* of lists, this will make it much more easy to manipulate it
* in the next steps.
*/
factories = g_new0 (GList *, numsinks);
for (i = 0; chains; i++) {
GList *elements = (GList *) chains->data;
factories[i] = elements;
chains = g_list_next (chains);
}
/*FIXME, free the list */
result = gst_bin_new ("autoplug_bin");
/*
* We now hav a list of lists that is probably like:
*
* !
* A -> B -> C
* !
* A -> D -> E
*
* we now try to find the common elements (A) and add them to
* the bin. We remove them from both lists too.
*/
while (factories[0]) {
GstElementFactory *factory;
GstElement *element;
gchar *name;
/* fase 3: add common elements */
factory = (GstElementFactory *) (factories[0]->data);
/* check to other paths for matching elements (factories) */
for (i=1; i<numsinks; i++) {
if (factory != (GstElementFactory *) (factories[i]->data)) {
goto differ;
}
}
GST_DEBUG (0,"common factory \"%s\"", GST_OBJECT_NAME (factory));
/* it is likely that the plugin is not loaded yet. thus when it loads it
* will replace the elementfactory that gst built from the cache, and the
* GST_OBJECT_NAME will no longer be valid. thus we must g_strdup its name.
*
* this might be an implementation problem, i don't know, if a program keeps
* a reference to a cached factory after a factory has been added on plugin
* initialization. i raelly don't know though.
*/
name = g_strdup (GST_OBJECT_NAME (factory));
element = gst_element_factory_create (factory, name);
g_free(name);
gst_bin_add (GST_BIN(result), element);
if (srcelement != NULL) {
gst_autoplug_pads_autoplug (srcelement, element);
}
/* this is the first element, find a good ghostpad */
else {
const GList *pads;
pads = gst_element_get_pad_list (element);
while (pads) {
GstPad *pad = GST_PAD (pads->data);
GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
if (gst_caps_is_always_compatible (srccaps, GST_PAD_TEMPLATE_CAPS (templ))) {
gst_element_add_ghost_pad (result, pad, "sink");
break;
}
pads = g_list_next (pads);
}
}
gst_autoplug_signal_new_object (GST_AUTOPLUG (autoplug), GST_OBJECT (element));
srcelement = element;
/* advance the pointer in all lists */
for (i=0; i<numsinks; i++) {
factories[i] = g_list_next (factories[i]);
}
have_common = TRUE;
}
differ:
/* loop over all the sink elements */
for (i = 0; i < numsinks; i++) {
GstElement *thesrcelement = srcelement;
GstElement *thebin = GST_ELEMENT(result);
while (factories[i]) {
/* fase 4: add other elements... */
GstElementFactory *factory;
GstElement *element;
factory = (GstElementFactory *)(factories[i]->data);
GST_DEBUG (0,"factory \"%s\"", GST_OBJECT_NAME (factory));
element = gst_element_factory_create(factory, GST_OBJECT_NAME (factory));
GST_DEBUG (0,"adding element %s", GST_ELEMENT_NAME (element));
gst_bin_add(GST_BIN(thebin), element);
gst_autoplug_signal_new_object (GST_AUTOPLUG (autoplug), GST_OBJECT (element));
gst_autoplug_pads_autoplug(thesrcelement, element);
/* this element is now the new source element */
thesrcelement = element;
factories[i] = g_list_next(factories[i]);
}
/*
* we're at the last element in the chain,
* find a suitable pad to turn into a ghostpad
*/
{
GstCaps *endcap = (GstCaps *)(endcaps->data);
const GList *pads = gst_element_get_pad_list (thesrcelement);
gboolean have_pad = FALSE;
endcaps = g_list_next (endcaps);
GST_DEBUG (0,"attempting to create a ghostpad for %s", GST_ELEMENT_NAME (thesrcelement));
while (pads) {
GstPad *pad = GST_PAD (pads->data);
GstPadTemplate *templ = GST_PAD_PAD_TEMPLATE (pad);
pads = g_list_next (pads);
if (gst_caps_is_always_compatible (GST_PAD_TEMPLATE_CAPS (templ), endcap)) {
gchar *name;
name = g_strdup_printf ("src_%02d", i);
gst_element_add_ghost_pad (result, pad, name);
g_free (name);
have_pad = TRUE;
break;
}
}
if (!have_pad) {
dynamic_pad_struct *data = g_new0(dynamic_pad_struct, 1);
data->result = result;
data->endcap = endcap;
data->i = i;
GST_DEBUG (0,"delaying the creation of a ghostpad for %s", GST_ELEMENT_NAME (thesrcelement));
g_signal_connect (G_OBJECT (thesrcelement), "new_pad",
G_CALLBACK (autoplug_dynamic_pad), data);
}
}
}
return result;
}
/*
* shortest path algorithm
*
*/
struct _gst_autoplug_node
{
gpointer iNode;
gpointer iPrev;
gint iDist;
};
typedef struct _gst_autoplug_node gst_autoplug_node;
static gint
find_factory (gst_autoplug_node *rgnNodes, gpointer factory)
{
gint i=0;
while (rgnNodes[i].iNode) {
if (rgnNodes[i].iNode == factory) return i;
i++;
}
return 0;
}
static GList*
construct_path (gst_autoplug_node *rgnNodes, gpointer factory)
{
GstElementFactory *current;
GList *factories = NULL;
current = rgnNodes[find_factory(rgnNodes, factory)].iPrev;
GST_INFO (GST_CAT_AUTOPLUG_ATTEMPT,"factories found in autoplugging (reversed order)");
while (current != NULL)
{
gpointer next = NULL;
next = rgnNodes[find_factory(rgnNodes, current)].iPrev;
if (next) {
factories = g_list_prepend (factories, current);
GST_INFO (GST_CAT_AUTOPLUG_ATTEMPT,"factory: \"%s\"", GST_OBJECT_NAME (current));
}
current = next;
}
return factories;
}
static GList*
gst_autoplug_enqueue (GList *queue, gpointer iNode, gint iDist, gpointer iPrev)
{
gst_autoplug_node *node = g_malloc (sizeof (gst_autoplug_node));
node->iNode = iNode;
node->iDist = iDist;
node->iPrev = iPrev;
queue = g_list_append (queue, node);
return queue;
}
static GList*
gst_autoplug_dequeue (GList *queue, gpointer *iNode, gint *iDist, gpointer *iPrev)
{
GList *head;
gst_autoplug_node *node;
head = g_list_first (queue);
if (head) {
node = (gst_autoplug_node *)head->data;
*iNode = node->iNode;
*iPrev = node->iPrev;
*iDist = node->iDist;
head = g_list_remove (queue, node);
}
return head;
}
static GList*
gst_autoplug_func (gpointer src, gpointer sink,
GstAutoplugListFunction list_function,
GstAutoplugCostFunction cost_function,
gpointer data)
{
gst_autoplug_node *rgnNodes;
GList *queue = NULL;
gpointer iNode, iPrev;
gint iDist, i, iCost;
GList *elements = g_list_copy ((GList *)list_function(data));
GList *factories;
guint num_factories;
elements = g_list_append (elements, sink);
elements = g_list_append (elements, src);
factories = elements;
num_factories = g_list_length (factories);
rgnNodes = g_new0 (gst_autoplug_node, num_factories+1);
for (i=0; i< num_factories; i++) {
gpointer fact = factories->data;
rgnNodes[i].iNode = fact;
rgnNodes[i].iPrev = NULL;
if (fact == src) {
rgnNodes[i].iDist = 0;
}
else {
rgnNodes[i].iDist = GST_AUTOPLUG_MAX_COST;
}
factories = g_list_next (factories);
}
rgnNodes[num_factories].iNode = NULL;
queue = gst_autoplug_enqueue (queue, src, 0, NULL);
while (g_list_length (queue) > 0) {
GList *factories2 = elements;
queue = gst_autoplug_dequeue (queue, &iNode, &iDist, &iPrev);
for (i=0; i< num_factories; i++) {
gpointer current = factories2->data;
iCost = cost_function (iNode, current, data);
if (iCost != GST_AUTOPLUG_MAX_COST) {
if ((GST_AUTOPLUG_MAX_COST == rgnNodes[i].iDist) ||
(rgnNodes[i].iDist > (iCost + iDist))) {
rgnNodes[i].iDist = iDist + iCost;
rgnNodes[i].iPrev = iNode;
queue = gst_autoplug_enqueue (queue, current, iDist + iCost, iNode);
}
}
factories2 = g_list_next (factories2);
}
}
return construct_path (rgnNodes, sink);
}