GstBin

Name

GstBin -- Base container element

Synopsis


#include <gst/gst.h>


enum        GstBinFlags;
struct      GstBin;
void        (*GstBinPrePostIterateFunction) (GstBin *bin,
                                             gpointer data);
GstElement* gst_bin_new                     (const gchar *name);
#define     gst_bin_destroy                 (bin)
void        gst_bin_add                     (GstBin *bin,
                                             GstElement *element);
void        gst_bin_add_many                (GstBin *bin,
                                             GstElement *element_1,
                                             ...);
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);
const 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_set_post_iterate_function
                                            (GstBin *bin,
                                             GstBinPrePostIterateFunction func,
                                             gpointer func_data);
void        gst_bin_set_pre_iterate_function
                                            (GstBin *bin,
                                             GstBinPrePostIterateFunction func,
                                             gpointer func_data);
void        gst_bin_child_state_change      (GstBin *bin,
                                             GstElementState oldstate,
                                             GstElementState newstate,
                                             GstElement *child);
void        gst_bin_auto_clock              (GstBin *bin);
GstClock*   gst_bin_get_clock               (GstBin *bin);
void        gst_bin_use_clock               (GstBin *bin,
                                             GstClock *clock);

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.

To control the selection of the clock in a bin, you can use the following methods: gst_bin_auto_clock() to let the bin select a clock automatically, gst_bin_get_clock() to get the current clock of the bin and gst_bin_use_clock() to specify a clock explicitly.

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 iterates itself */
  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 + 5
} GstBinFlags;

Flags for a bin.


struct GstBin

struct GstBin;


GstBinPrePostIterateFunction ()

void        (*GstBinPrePostIterateFunction) (GstBin *bin,
                                             gpointer data);

The signature of the callback for the post and pre iterate function as set with gst_bin_set_pre_iterate_function() and gst_bin_set_post_iterate_function().


gst_bin_new ()

GstElement* gst_bin_new                     (const gchar *name);

Create a new bin with given name.


gst_bin_destroy()

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

Free the memory allocated by this bin


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.


gst_bin_add_many ()

void        gst_bin_add_many                (GstBin *bin,
                                             GstElement *element_1,
                                             ...);

Add a list of elements to a bin. Uses gst_bin_add.


gst_bin_remove ()

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

Remove the element from its associated bin, unparenting as well. The element will also be unreferenced so there's no need to call gst_object_unref on it. If you want the element to still exist after removing, you need to call gst_object_ref before removing it from the bin.


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.


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.


gst_bin_get_list ()

const GList* gst_bin_get_list               (GstBin *bin);

Get the list of elements in this bin.


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.


gst_bin_iterate ()

gboolean    gst_bin_iterate                 (GstBin *bin);

Iterates over the elements in this bin.


gst_bin_set_post_iterate_function ()

void        gst_bin_set_post_iterate_function
                                            (GstBin *bin,
                                             GstBinPrePostIterateFunction func,
                                             gpointer func_data);

Attaches a callback which will be run after every iteration of the bin


gst_bin_set_pre_iterate_function ()

void        gst_bin_set_pre_iterate_function
                                            (GstBin *bin,
                                             GstBinPrePostIterateFunction func,
                                             gpointer func_data);

Attaches a callback which will be run before every iteration of the bin


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.


gst_bin_auto_clock ()

void        gst_bin_auto_clock              (GstBin *bin);

Let the bin select a clock automatically.


gst_bin_get_clock ()

GstClock*   gst_bin_get_clock               (GstBin *bin);

Gets the current clock of the (scheduler of the) bin.


gst_bin_use_clock ()

void        gst_bin_use_clock               (GstBin *bin,
                                             GstClock *clock);

Force the bin to use the given clock. Use NULL to force it to use no clock at all.

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