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GstBinGstBin — |
#include <gst/gst.h> GstBin; GstBinClass; GstElement* gst_bin_new (const gchar *name); gboolean gst_bin_add (GstBin *bin, GstElement *element); gboolean gst_bin_remove (GstBin *bin, GstElement *element); GstElement* gst_bin_get_by_name (GstBin *bin, const gchar *name); GstElement* gst_bin_get_by_name_recurse_up (GstBin *bin, const gchar *name); GstElement* gst_bin_get_by_interface (GstBin *bin, GType interface); GstIterator* gst_bin_iterate_elements (GstBin *bin); GstIterator* gst_bin_iterate_recurse (GstBin *bin); GstIterator* gst_bin_iterate_sinks (GstBin *bin); GstIterator* gst_bin_iterate_sorted (GstBin *bin); GstIterator* gst_bin_iterate_all_by_interface (GstBin *bin, GType interface); void gst_bin_add_many (GstBin *bin, GstElement *element_1, ...); void gst_bin_remove_many (GstBin *bin, GstElement *element_1, ...); enum GstBinFlags; #define GST_BIN_CHILDREN (bin) #define GST_BIN_CHILDREN_COOKIE (bin) #define GST_BIN_NUMCHILDREN (bin)
"element-added" void user_function (GstBin *bin, GstElement *element, gpointer user_data); "element-removed" void user_function (GstBin *bin, GstElement *element, gpointer user_data);
typedef struct { /* our children, subclass are supposed to update these * fields to reflect their state with _iterate_*() */ gint numchildren; GList *children; guint32 children_cookie; GstBus *child_bus; GList *messages; gboolean polling; gboolean state_dirty; gboolean clock_dirty; GstClock *provided_clock; GstElement *clock_provider; } GstBin;
The GstBin base class. Subclasses can access these fields provided the LOCK is taken.
gint numchildren ; | the number of children in this bin |
GList *children ; | the list of children in this bin |
guint32 children_cookie ; | updated whenever children changes
|
GstBus *child_bus ; | internal bus for handling child messages |
GList *messages ; | queued messages |
gboolean polling ; | the bin is currently calculating its state |
gboolean state_dirty ; | the bin needs to recalculate its state |
gboolean clock_dirty ; | the bin needs to select a new clock |
GstClock *provided_clock ; | the last clock selected |
GstElement *clock_provider ; | the element that provided provided_clock
|
typedef struct { GstElementClass parent_class; /* virtual methods for subclasses */ gboolean (*add_element) (GstBin *bin, GstElement *element); gboolean (*remove_element) (GstBin *bin, GstElement *element); void (*handle_message) (GstBin *bin, GstMessage *message); } GstBinClass;
Subclasses can override the add_element
and remove_element
to
update the list of children in the bin.
The handle_message
method can be overriden to implement custom
message handling.
GstElementClass parent_class ; | bin parent class |
add_element () | method to add an element to a bin |
remove_element () | method to remove an element from a bin |
handle_message () | method to handle a message from the children |
GstElement* gst_bin_new (const gchar *name);
Creates a new bin with the given name.
name : | the name of the new bin |
Returns : | a new GstBin |
gboolean gst_bin_add (GstBin *bin, GstElement *element);
Adds the given element to the bin. Sets the element's parent, and thus takes ownership of the element. An element can only be added to one bin.
If the element's pads are linked to other pads, the pads will be unlinked before the element is added to the bin.
MT safe.
bin : | a GstBin |
element : | the GstElement to add |
Returns : | TRUE if the element could be added, FALSE if the bin does not want to accept the element. |
gboolean gst_bin_remove (GstBin *bin, GstElement *element);
Removes the element from the bin, unparenting it as well.
Unparenting the element means that the element will be dereferenced,
so if the bin holds the only reference to the element, the element
will be freed in the process of removing it from the bin. If you
want the element to still exist after removing, you need to call
gst_object_ref()
before removing it from the bin.
If the element's pads are linked to other pads, the pads will be unlinked before the element is removed from the bin.
MT safe.
bin : | a GstBin |
element : | the GstElement to remove |
Returns : | TRUE if the element could be removed, FALSE if the bin does not want to remove the element. |
GstElement* gst_bin_get_by_name (GstBin *bin, const gchar *name);
Gets the element with the given name from a bin. This function recurses into child bins.
Returns NULL if no element with the given name is found in the bin.
MT safe. Caller owns returned reference.
bin : | a GstBin |
name : | the element name to search for |
Returns : | the GstElement with the given name, or NULL |
GstElement* gst_bin_get_by_name_recurse_up (GstBin *bin, const gchar *name);
Gets the element with the given name from this bin. If the element is not found, a recursion is performed on the parent bin.
Returns NULL if: - no element with the given name is found in the bin
MT safe. Caller owns returned reference.
bin : | a GstBin |
name : | the element name to search for |
Returns : | the GstElement with the given name, or NULL |
GstElement* gst_bin_get_by_interface (GstBin *bin, GType interface);
Looks for an element inside the bin that implements the given
interface. If such an element is found, it returns the element.
You can cast this element to the given interface afterwards. If you want
all elements that implement the interface, use
gst_bin_iterate_all_by_interface()
. This function recurses into child bins.
MT safe. Caller owns returned reference.
bin : | a GstBin |
interface : | the GType of an interface |
Returns : | A GstElement inside the bin implementing the interface |
GstIterator* gst_bin_iterate_elements (GstBin *bin);
Gets an iterator for the elements in this bin.
Each element yielded by the iterator will have its refcount increased, so unref after use.
MT safe. Caller owns returned value.
bin : | a GstBin |
Returns : | a GstIterator of GstElement, or NULL |
GstIterator* gst_bin_iterate_recurse (GstBin *bin);
Gets an iterator for the elements in this bin. This iterator recurses into GstBin children.
Each element yielded by the iterator will have its refcount increased, so unref after use.
MT safe. Caller owns returned value.
bin : | a GstBin |
Returns : | a GstIterator of GstElement, or NULL |
GstIterator* gst_bin_iterate_sinks (GstBin *bin);
Gets an iterator for all elements in the bin that have the GST_ELEMENT_IS_SINK flag set.
Each element yielded by the iterator will have its refcount increased, so unref after use.
MT safe. Caller owns returned value.
bin : | a GstBin |
Returns : | a GstIterator of GstElement, or NULL |
GstIterator* gst_bin_iterate_sorted (GstBin *bin);
Gets an iterator for the elements in this bin in topologically sorted order. This means that the elements are returned from the most downstream elements (sinks) to the sources.
This function is used internally to perform the state changes of the bin elements.
Each element yielded by the iterator will have its refcount increased, so unref after use.
MT safe. Caller owns returned value.
bin : | a GstBin |
Returns : | a GstIterator of GstElement, or NULL |
GstIterator* gst_bin_iterate_all_by_interface (GstBin *bin, GType interface);
Looks for all elements inside the bin that implements the given interface. You can safely cast all returned elements to the given interface. The function recurses inside child bins. The iterator will yield a series of GstElement that should be unreffed after use.
Each element yielded by the iterator will have its refcount increased, so unref after use.
MT safe. Caller owns returned value.
bin : | a GstBin |
interface : | the GType of an interface |
Returns : | a GstIterator of GstElement for all elements in the bin implementing the given interface, or NULL |
void gst_bin_add_many (GstBin *bin, GstElement *element_1, ...);
Adds a NULL-terminated list of elements to a bin. This function is
equivalent to calling gst_bin_add()
for each member of the list.
bin : | a GstBin |
element_1 : | the GstElement element to add to the bin |
... : | additional elements to add to the bin |
void gst_bin_remove_many (GstBin *bin, GstElement *element_1, ...);
Remove a list of elements from a bin. This function is equivalent
to calling gst_bin_remove()
with each member of the list.
bin : | a GstBin |
element_1 : | the first GstElement to remove from the bin |
... : | NULL-terminated list of elements to remove from the bin |
typedef enum { /* padding */ GST_BIN_FLAG_LAST = (GST_ELEMENT_FLAG_LAST << 5) } GstBinFlags;
GstBinFlags are a set of flags specific to bins. Most are set/used
internally. They can be checked using the GST_OBJECT_FLAG_IS_SET()
macro,
and (un)set using GST_OBJECT_FLAG_SET()
and GST_OBJECT_FLAG_UNSET()
.
GST_BIN_FLAG_LAST | the last enum in the series of flags for bins. Derived classes can use this as first value in a list of flags. |
#define GST_BIN_CHILDREN(bin) (GST_BIN_CAST(bin)->children)
Gets the list with children in a bin.
bin : | a GstBin |
#define GST_BIN_CHILDREN_COOKIE(bin) (GST_BIN_CAST(bin)->children_cookie)
Gets the children cookie that watches the children list.
bin : | a GstBin |
#define GST_BIN_NUMCHILDREN(bin) (GST_BIN_CAST(bin)->numchildren)
Gets the number of children in a bin.
bin : | a GstBin |
void user_function (GstBin *bin, GstElement *element, gpointer user_data);
Will be emitted after the element was added to the bin.
bin : | the GstBin |
element : | the GstElement that was added to the bin |
user_data : | user data set when the signal handler was connected. |
void user_function (GstBin *bin, GstElement *element, gpointer user_data);
Will be emitted after the element was removed from the bin.
bin : | the GstBin |
element : | the GstElement that was removed from the bin |
user_data : | user data set when the signal handler was connected. |
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