pub struct Pipeline { /* fields omitted */ }A GstPipeline is a special GstBin used as the toplevel container for the filter graph. The GstPipeline will manage the selection and distribution of a global GstClock as well as provide a GstBus to the application.
gst_pipeline_new() is used to create a pipeline. when you are done with the pipeline, use gst_object_unref() to free its resources including all added GstElement objects (if not otherwise referenced).
Elements are added and removed from the pipeline using the GstBin methods like gst_bin_add() and gst_bin_remove() (see GstBin).
Before changing the state of the GstPipeline (see GstElement) a GstBus can be retrieved with gst_pipeline_get_bus(). This bus can then be used to receive GstMessage from the elements in the pipeline.
By default, a GstPipeline will automatically flush the pending GstBus messages when going to the NULL state to ensure that no circular references exist when no messages are read from the GstBus. This behaviour can be changed with gst_pipeline_set_auto_flush_bus().
When the GstPipeline performs the PAUSED to PLAYING state change it will select a clock for the elements. The clock selection algorithm will by default select a clock provided by an element that is most upstream (closest to the source). For live pipelines (ones that return GST_STATE_CHANGE_NO_PREROLL from the gst_element_set_state() call) this will select the clock provided by the live source. For normal pipelines this will select a clock provided by the sinks (most likely the audio sink). If no element provides a clock, a default GstSystemClock is used.
The clock selection can be controlled with the gst_pipeline_use_clock() method, which will enforce a given clock on the pipeline. With gst_pipeline_auto_clock() the default clock selection algorithm can be restored.
A GstPipeline maintains a running time for the elements. The running time is defined as the difference between the current clock time and the base time. When the pipeline goes to READY or a flushing seek is performed on it, the running time is reset to 0. When the pipeline is set from PLAYING to PAUSED, the current clock time is sampled and used to configure the base time for the elements when the pipeline is set to PLAYING again. The effect is that the running time (as the difference between the clock time and the base time) will count how much time was spent in the PLAYING state. This default behaviour can be changed with the gst_element_set_start_time() method.
Create a new pipeline with the given name.
Creates a new pipeline based on the command-line syntax
Gets the GstBus of pipeline . The bus allows applications to
receive Message packets.
Get the configured delay (see set_delay()).
Set the expected delay needed for all elements to perform the
PAUSED to PLAYING state change. delay will be added to the base
time of the elements so that they wait an additional delay amount
of time before starting to process buffers and cannot be
GST_CLOCK_TIME_NONE.
This option is used for tuning purposes and should normally not be used.
Returns a const raw pointer to the internal GstElement
Returns a mut raw pointer to the internal GstElement
Adds the given element to the bin. Sets the element's parent,
and thus adds a reference.
If the element's pads are linked to other pads, the pads will
be unlinked before the element is added to the bin.
When you add an element to an already-running pipeline, you
will have to take care to set the state of the newly-added
element to the desired state (usually PLAYING or PAUSED, same
you set the pipeline to originally) with Element::set_state(),
or use gst_element_sync_state_with_parent(). The bin or pipeline
will not take care of this for you.
Remove the element from its associated bin.
If the element's pads are linked to other pads, the pads will be
unlinked before the element is removed from the bin.
Get the element with the given name from this bin.
Returns None if no element with the given name is found in the bin.
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 None if no element with the given name is found in the bin.
Query bin for the current latency using and reconfigures this latency
to all the elements with a LATENCY event.
This method is typically called on the pipeline when a
GST_MESSAGE_LATENCY is posted on the bus.
This function simply emits the 'do-latency' signal so any custom
latency calculations will be performed.
If set to true, the bin will handle asynchronous state changes.
This should be used only if the bin subclass is modifying the state
of its children on its own
Forward all children messages, even those that would normally be
filtered by the bin. This can be interesting when one wants to be
notified of the EOS state of individual elements, for example.
The messages are converted to an ELEMENT message with the bin as the
source. The structure of the message is named 'GstBinForwarded' and
contains a field named 'message' of type GST_TYPE_MESSAGE that
contains the original forwarded message.
Returns a const raw pointer to the internal GstElement
Returns a mut raw pointer to the internal GstElement
Consumes the current object and transfers ownership of the raw pointer Used to transfer ownership to ffi functions, should be used when an ffi function expects full transfer of an object to avoid the original object to be unreferenced in the process Read more
The resulting type after dereferencing.
Mutably dereferences the value.