GstBin

Name

GstBin -- Base container element

Synopsis


#include <gst/gst.h>


enum        GstBinFlags;
struct      GstBin;
GstElement* gst_bin_new                     (const gchar *name);
#define     gst_bin_destroy                 (bin)
void        gst_bin_add                     (GstBin *bin,
                                             GstElement *element);
void        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);
GList*      gst_bin_get_list                (GstBin *bin);
gboolean    gst_bin_set_state_type          (GstBin *bin,
                                             GstElementState state,
                                             GType type);
gboolean    gst_bin_iterate                 (GstBin *bin);
void        gst_bin_child_state_change      (GstBin *bin,
                                             GstElementState oldstate,
                                             GstElementState newstate,
                                             GstElement *child);
void        gst_bin_child_error             (GstBin *bin,
                                             GstElement *child);

Object Hierarchy


  GObject
   +----GstObject
         +----GstElement
               +----GstBin

Signal Prototypes


"object-added"
            void        user_function      (GstBin *gstbin,
                                            gpointer arg1,
                                            gpointer user_data);

Description

GstBin is the simplest of the container elements, allowing elements to become children of itself. Pads from the child elements can be ghosted to the bin, making the bin itself look transparently like any other element, allowing for deep nesting of predefined sub-pipelines.

A new GstBin is created with gst_bin_new(). Use a GstPipeline instead if you want to create a toplevel bin because a normal bin doesn't have a scheduler of its own.

After the bin has been created you will typically add elements to it with gst_bin_add(). You can remove elements with gst_bin_remove().

An element can be retrieved from a bin with gst_bin_get_by_name(), using the elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal purposes and will query the parent bins when the element is not found in the current bin.

The list of elements in a bin can be retrieved with gst_bin_get_list().

After the bin has been set to the PLAYING state (with gst_element_set_state()), gst_bin_iterate() is used to process the elements in the bin.

The "object_added" signal is fired whenever a new object is added to the bin.

gst_bin_destroy() is used to destroy the bin.

Details

enum GstBinFlags

typedef enum {
  /* this bin is a manager of child elements, i.e. a pipeline or thread */
  GST_BIN_FLAG_MANAGER		= GST_ELEMENT_FLAG_LAST,
  /* this bin is actually a meta-bin, and may need to be scheduled */
  GST_BIN_SELF_SCHEDULABLE,

  /* we prefer to have cothreads when its an option, over chain-based */
  GST_BIN_FLAG_PREFER_COTHREADS,

  GST_BIN_FLAG_FIXED_CLOCK,

  /* padding */
  GST_BIN_FLAG_LAST		= GST_ELEMENT_FLAG_LAST + 4,
} GstBinFlags;

Flags for a bin.


struct GstBin

struct GstBin;


gst_bin_new ()

GstElement* gst_bin_new                     (const gchar *name);

Create a new bin with given name.

name : name of new bin
Returns : new bin


gst_bin_destroy()

#define		gst_bin_destroy(bin)		gst_object_destroy(GST_OBJECT(bin))

Free the memory allocated by this bin

bin :the bin to free


gst_bin_add ()

void        gst_bin_add                     (GstBin *bin,
                                             GstElement *element);

Add the given element to the bin. Set the elements parent, and thus add a reference.

bin : GstBin to add element to
element : GstElement to add to bin


gst_bin_remove ()

void        gst_bin_remove                  (GstBin *bin,
                                             GstElement *element);

Remove the element from its associated bin, unparenting as well.

bin : GstBin to remove element from
element : GstElement to remove


gst_bin_get_by_name ()

GstElement* gst_bin_get_by_name             (GstBin *bin,
                                             const gchar *name);

Get the element with the given name from this bin.

bin : Gstbin to search
name : the element name to search for
Returns : the element with the given name


gst_bin_get_by_name_recurse_up ()

GstElement* gst_bin_get_by_name_recurse_up  (GstBin *bin,
                                             const gchar *name);

Get the element with the given name from this bin. If the element is not found, a recursion is performed on the parent bin.

bin : Gstbin to search
name : the element name to search for
Returns : the element with the given name


gst_bin_get_list ()

GList*      gst_bin_get_list                (GstBin *bin);

Get the list of elements in this bin.

bin : Gstbin to get the list from
Returns : a GList of elements


gst_bin_set_state_type ()

gboolean    gst_bin_set_state_type          (GstBin *bin,
                                             GstElementState state,
                                             GType type);

Sets the state of only those objects of the given type.

bin : GstBin to set the state
state : the new state to set the elements to
type : the type of elements to change
Returns : indication if the state change was successfull


gst_bin_iterate ()

gboolean    gst_bin_iterate                 (GstBin *bin);

Iterates over the elements in this bin.

bin : Gstbin to iterate
Returns : TRUE if the bin did something usefull. This value can be used to determine it the bin is in EOS.


gst_bin_child_state_change ()

void        gst_bin_child_state_change      (GstBin *bin,
                                             GstElementState oldstate,
                                             GstElementState newstate,
                                             GstElement *child);

An internal function to inform the parent bin about a state change of a child.

bin : GstBin with the child
oldstate : The old child state
newstate : The new child state
child : GstElement that signaled an changed state


gst_bin_child_error ()

void        gst_bin_child_error             (GstBin *bin,
                                             GstElement *child);

bin : 
child : 

Signals

The "object-added" signal

void        user_function                  (GstBin *gstbin,
                                            gpointer arg1,
                                            gpointer user_data);

is signaled whenever a new GstElement is added to the GstBin

gstbin :the object which received the signal.
arg1 :the element that was added
user_data :user data set when the signal handler was connected.