Since the application typically only wants to deal with delivery of these messages from one thread, the GstBus will marshall the messages between different threads. This is important since the actual streaming of media is done in another thread than the application.
The GstBus provides support for glib.Source based notifications. This makes it possible to handle the delivery in the glib mainloop.
The bus can be polled with the Bus.poll method. This methods blocks up to the specified timeout value until one of the specified messages types is posted on the bus. The application can then Bus.pop the messages from the bus to handle them. Alternatively the application can register an asynchronous bus function using Bus.addWatchFull or Bus.addWatch. This function will install a glib.Source in the default glib main loop and will deliver messages a short while after they have been posted. Note that the main loop should be running for the asynchronous callbacks.
It is also possible to get messages from the bus without any thread marshalling with the Bus.setSyncHandler method. This makes it possible to react to a message in the same thread that posted the message on the bus. This should only be used if the application is able to deal with messages from different threads.
Every gstreamer.Pipeline has one bus.
Note that a gstreamer.Pipeline will set its bus into flushing state when changing from READY to NULL state.
Sets our main struct and passes it to the parent class.
Creates a new gstreamer.Bus instance.
A message has been posted on the bus. This signal is emitted from a GSource added to the mainloop. this signal will only be emitted when there is a mainloop running.
A message has been posted on the bus. This signal is emitted from the thread that posted the message so one has to be careful with locking.
Adds a bus signal watch to the default main context with the default priority (G_PRIORITY_DEFAULT). It is also possible to use a non-default main context set up using MainContext.pushThreadDefault (before one had to create a bus watch source and attach it to the desired main context 'manually').
Adds a bus signal watch to the default main context with the given priority (e.g. G_PRIORITY_DEFAULT). It is also possible to use a non-default main context set up using MainContext.pushThreadDefault (before one had to create a bus watch source and attach it to the desired main context 'manually').
Adds a bus watch to the default main context with the default priority. This function is used to receive asynchronous messages in the main loop. The watch can be removed using Source.remove or by returning FALSE from func. MT safe.
Adds a bus watch to the default main context with the given priority (e.g. G_PRIORITY_DEFAULT). It is also possible to use a non-default main context set up using MainContext.pushThreadDefault (before one had to create a bus watch source and attach it to the desired main context 'manually').
A helper GstBusFunc that can be used to convert all asynchronous messages into signals.
Create watch for this bus. The GSource will be dispatched whenever a message is on the bus. After the GSource is dispatched, the message is popped off the bus and unreffed.
Instructs GStreamer to stop emitting the "sync-message" signal for this bus. See Bus.enableSyncMessageEmission for more information.
Instructs GStreamer to emit the "sync-message" signal after running the bus's sync handler. This function is here so that code can ensure that they can synchronously receive messages without having to affect what the bin's sync handler is.
Get the main Gtk struct
Gets the file descriptor from the bus which can be used to get notified about messages being available with functions like g_poll(), and allows integration into other event loops based on file descriptors. Whenever a message is available, the POLLIN / G_IO_IN event is set.
the main Gtk struct as a void*
Check if there are pending messages on the bus that should be handled.
Peek the message on the top of the bus' queue. The message will remain on the bus' message queue. A reference is returned, and needs to be unreffed by the caller.
Poll the bus for messages. Will block while waiting for messages to come. You can specify a maximum time to poll with the timeout parameter. If timeout is negative, this function will block indefinitely.
Get a message from the bus.
Get a message matching type from the bus. Will discard all messages on the bus that do not match type and that have been posted before the first message that does match type. If there is no message matching type on the bus, all messages will be discarded. It is not possible to use message enums beyond GST_MESSAGE_EXTENDED in the events mask.
Post a message on the given bus. Ownership of the message is taken by the bus.
Removes a signal watch previously added with Bus.addSignalWatch.
Removes an installed bus watch from bus.
If flushing, flush out and unref any messages queued in the bus. Releases references to the message origin objects. Will flush future messages until Bus.setFlushing sets flushing to FALSE.
Use this for making an XOverlay. Sets the synchronous handler on the bus. The function will be called every time a new message is posted on the bus. Note that the function will be called in the same thread context as the posting object. This function is usually only called by the creator of the bus. Applications should handle messages asynchronously using the gst_bus watch and poll functions. You cannot replace an existing sync_handler. You can pass NULL to this function, which will clear the existing handler.
A helper GstBusSyncHandler that can be used to convert all synchronous messages into signals.
Get a message from the bus, waiting up to the specified timeout.
Get a message from the bus whose type matches the message type mask types, waiting up to the specified timeout (and discarding any messages that do not match the mask provided).
the main Gtk struct
the main Gtk struct
Get the main Gtk struct
the main Gtk struct as a void*
Checks to see if there is any object named name in list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each GstObject in the list to compare the name, so be careful when passing a list with a locked object.
A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print.
Increase the reference count of object, and possibly remove the floating reference, if object has a floating reference.
Atomically modifies a pointer to point to a new object. The reference count of oldobj is decreased and the reference count of newobj is increased.
A default error function that uses g_printerr() to display the error message and the optional debug sting..
Gets the corresponding gstreamer.ControlBinding for the property. This should be unreferenced again after use.
Obtain the control-rate for this object. Audio processing gstreamer.Element objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() inbetween. The length of the processing segment should be up to control-rate nanoseconds.
Returns a copy of the name of object. Caller should g_free() the return value after usage. For a nameless object, this returns NULL, which you can safely g_free() as well.
Returns the parent of object. This function increases the refcount of the parent object so you should gst_object_unref() it after usage.
Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging.
Gets the value for the given controlled property at the requested time.
Gets a number of values for the given controlled property starting at the requested time. The array values need to hold enough space for n_values of the same type as the objects property's type.
Check if the object has active controlled properties.
Increments the reference count on object. This function does not take the lock on object because it relies on atomic refcounting.
Removes the corresponding gstreamer.ControlBinding If it was the last ref of the binding, it will be disposed.
This function is used to disable the control bindings on a property for some time, i.e. gst_object_sync_values() will do nothing for the property.
This function is used to disable all controlled properties of the object for some time, i.e. gst_object_sync_values() will do nothing.
Change the control-rate for this object. Audio processing gstreamer.Element objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() inbetween. The length of the processing segment should be up to control-rate nanoseconds.
Sets the name of object, or gives object a guaranteed unique name (if name is NULL). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.
Sets the parent of object to parent. The object's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
Returns a suggestion for timestamps where buffers should be split to get best controller results.
Sets the properties of the object, according to the gstreamer.ControlSources that (maybe) handle them and for the given timestamp.
Clear the parent of object, removing the associated reference. This function decreases the refcount of object.
Decrements the reference count on object. If reference count hits zero, destroy object. This function does not take the lock on object as it relies on atomic refcounting.
The deep notify signal is used to be notified of property changes. It is typically attached to the toplevel bin to receive notifications from all the elements contained in that bin.