Membrane Core v0.3.0 Membrane.Pipeline behaviour View Source
Module containing functions for constructing and supervising pipelines.
Pipelines are units that make it possible to instantiate, link and manage elements in convenient way (actually elements should always be used inside a pipeline). Linking elements together enables them to pass data to one another, and process it in different ways.
Link to this section Summary
Types
Type describing actions that can be returned from pipeline callbacks
Type that defines all valid return values from most callbacks
Action that sends a message to element identified by name
Defines options that can be passed to start/3
/ start_link/3
and received
in handle_init/1
callback
Action that stops, unlinks and removes specified child/children from pipeline
Action that instantiates elements and links them according to Membrane.Pipeline.Spec
Functions
Changes the playback state to the new_state
Returns a specification to start this module under a supervisor
Checks whether module is a pipeline
Changes playback state to :playing
Changes playback state to :prepared
Does the same as start_link/3
but starts process outside of supervision tree
Starts the Pipeline based on given module and links it to the current process
Changes playback state to :stopped
Changes pipeline's playback state to :stopped
and terminates its process
Callbacks
Callback invoked on initialization of pipeline process. It should parse options
and initialize element internal state. Internally it is invoked inside
GenServer.init/1
callback
Callback invoked when a notification comes in from an element
Callback invoked when pipeline receives a message that is not recognized as an internal membrane message
Callback invoked when pipeline transition from :playing
to :prepared
state has finished,
that is all of its elements are prepared to be stopped
Callback invoked when pipeline is in :playing
state, i.e. all its elements
are in this state
Callback invoked when pipeline is in :playing
state, i.e. all its elements
are in this state
Callback invoked when Membrane.Pipeline.Spec
is linked and in the same playback
state as pipeline
Callback invoked when pipeline transition from :stopped
to :prepared
state has finished,
that is all of its elements are prepared to enter :playing
state
Enables to check whether module is membrane pipeline
Link to this section Types
action_t()
View Source
action_t() :: forward_action_t() | spec_action_t() | remove_child_action_t()
action_t() :: forward_action_t() | spec_action_t() | remove_child_action_t()
Type describing actions that can be returned from pipeline callbacks.
Returning actions is a way of pipeline interaction with its elements and other parts of framework.
callback_return_t()
View Source
callback_return_t() ::
Membrane.Core.CallbackHandler.callback_return_t(
action_t(),
Membrane.Pipeline.State.internal_state_t()
)
callback_return_t() :: Membrane.Core.CallbackHandler.callback_return_t( action_t(), Membrane.Pipeline.State.internal_state_t() )
Type that defines all valid return values from most callbacks.
forward_action_t()
View Source
forward_action_t() ::
{:forward, {Membrane.Element.name_t(), Membrane.Notification.t()}}
forward_action_t() :: {:forward, {Membrane.Element.name_t(), Membrane.Notification.t()}}
Action that sends a message to element identified by name.
pipeline_options_t()
View Source
pipeline_options_t() :: any()
pipeline_options_t() :: any()
Defines options that can be passed to start/3
/ start_link/3
and received
in handle_init/1
callback.
playback_state_t()
View Source
playback_state_t() :: :stopped | :prepared | :playing
playback_state_t() :: :stopped | :prepared | :playing
remove_child_action_t()
View Source
remove_child_action_t() ::
{:remove_child, Membrane.Element.name_t() | [Membrane.Element.name_t()]}
remove_child_action_t() :: {:remove_child, Membrane.Element.name_t() | [Membrane.Element.name_t()]}
Action that stops, unlinks and removes specified child/children from pipeline.
spec_action_t()
View Source
spec_action_t() :: {:spec, Membrane.Pipeline.Spec.t()}
spec_action_t() :: {:spec, Membrane.Pipeline.Spec.t()}
Action that instantiates elements and links them according to Membrane.Pipeline.Spec
.
Elements playback state is changed to the current pipeline state.
c:handle_spec_started
callback is executed once it happens.
Link to this section Functions
change_playback_state(pid, new_state)
View Source
change_playback_state(pid(), playback_state_t()) :: :ok
change_playback_state(pid(), playback_state_t()) :: :ok
Changes the playback state to the new_state
.
child_spec(init_arg) View Source
Returns a specification to start this module under a supervisor.
See Supervisor
.
pipeline?(module) View Source
Checks whether module is a pipeline.
play(pid)
View Source
play(pid()) :: :ok
play(pid()) :: :ok
Changes playback state to :playing
.
An alias for change_playback_state/2
with proper state.
prepare(pid)
View Source
prepare(pid()) :: :ok
prepare(pid()) :: :ok
Changes playback state to :prepared
.
An alias for change_playback_state/2
with proper state.
start(module, pipeline_options \\ nil, process_options \\ [])
View Source
start(
module(),
pipeline_options :: pipeline_options_t(),
process_options :: GenServer.options()
) :: GenServer.on_start()
start( module(), pipeline_options :: pipeline_options_t(), process_options :: GenServer.options() ) :: GenServer.on_start()
Does the same as start_link/3
but starts process outside of supervision tree.
start_link(module, pipeline_options \\ nil, process_options \\ [])
View Source
start_link(
module(),
pipeline_options :: pipeline_options_t(),
process_options :: GenServer.options()
) :: GenServer.on_start()
start_link( module(), pipeline_options :: pipeline_options_t(), process_options :: GenServer.options() ) :: GenServer.on_start()
Starts the Pipeline based on given module and links it to the current process.
Pipeline options are passed to module's handle_init/1
callback.
Process options are internally passed to GenServer.start_link/3
.
Returns the same values as GenServer.start_link/3
.
stop(pid)
View Source
stop(pid()) :: :ok
stop(pid()) :: :ok
Changes playback state to :stopped
.
An alias for change_playback_state/2
with proper state.
stop_and_terminate(pipeline)
View Source
stop_and_terminate(pipeline :: pid()) :: :ok
stop_and_terminate(pipeline :: pid()) :: :ok
Changes pipeline's playback state to :stopped
and terminates its process
Link to this section Callbacks
handle_init(options)
View Source
handle_init(options :: pipeline_options_t()) ::
{{:ok, Membrane.Pipeline.Spec.t()},
Membrane.Pipeline.State.internal_state_t()}
| {:error, any()}
handle_init(options :: pipeline_options_t()) :: {{:ok, Membrane.Pipeline.Spec.t()}, Membrane.Pipeline.State.internal_state_t()} | {:error, any()}
Callback invoked on initialization of pipeline process. It should parse options
and initialize element internal state. Internally it is invoked inside
GenServer.init/1
callback.
handle_notification(notification, element, state)
View Source
handle_notification(
notification :: Membrane.Notification.t(),
element :: Membrane.Element.name_t(),
state :: Membrane.Pipeline.State.internal_state_t()
) :: callback_return_t()
handle_notification( notification :: Membrane.Notification.t(), element :: Membrane.Element.name_t(), state :: Membrane.Pipeline.State.internal_state_t() ) :: callback_return_t()
Callback invoked when a notification comes in from an element.
handle_other(message, state)
View Source
handle_other(
message :: any(),
state :: Membrane.Pipeline.State.internal_state_t()
) :: callback_return_t()
handle_other( message :: any(), state :: Membrane.Pipeline.State.internal_state_t() ) :: callback_return_t()
Callback invoked when pipeline receives a message that is not recognized as an internal membrane message.
Useful for receiving ticks from timer, data sent from NIFs or other stuff.
handle_playing_to_prepared(state)
View Source
handle_playing_to_prepared(state :: Membrane.Pipeline.State.internal_state_t()) ::
callback_return_t()
handle_playing_to_prepared(state :: Membrane.Pipeline.State.internal_state_t()) :: callback_return_t()
Callback invoked when pipeline transition from :playing
to :prepared
state has finished,
that is all of its elements are prepared to be stopped.
handle_prepared_to_playing(state)
View Source
handle_prepared_to_playing(state :: Membrane.Pipeline.State.internal_state_t()) ::
callback_return_t()
handle_prepared_to_playing(state :: Membrane.Pipeline.State.internal_state_t()) :: callback_return_t()
Callback invoked when pipeline is in :playing
state, i.e. all its elements
are in this state.
handle_prepared_to_stopped(state)
View Source
handle_prepared_to_stopped(state :: Membrane.Pipeline.State.internal_state_t()) ::
callback_return_t()
handle_prepared_to_stopped(state :: Membrane.Pipeline.State.internal_state_t()) :: callback_return_t()
Callback invoked when pipeline is in :playing
state, i.e. all its elements
are in this state.
handle_spec_started(elements, state)
View Source
handle_spec_started(
elements :: [Membrane.Element.name_t()],
state :: Membrane.Pipeline.State.internal_state_t()
) :: callback_return_t()
handle_spec_started( elements :: [Membrane.Element.name_t()], state :: Membrane.Pipeline.State.internal_state_t() ) :: callback_return_t()
Callback invoked when Membrane.Pipeline.Spec
is linked and in the same playback
state as pipeline.
Spec can be started from handle_init/1
callback or as spec_action_t/0
action.
handle_stopped_to_prepared(state)
View Source
handle_stopped_to_prepared(state :: Membrane.Pipeline.State.internal_state_t()) ::
callback_return_t()
handle_stopped_to_prepared(state :: Membrane.Pipeline.State.internal_state_t()) :: callback_return_t()
Callback invoked when pipeline transition from :stopped
to :prepared
state has finished,
that is all of its elements are prepared to enter :playing
state.
membrane_pipeline?()
View Source
membrane_pipeline?() :: true
membrane_pipeline?() :: true
Enables to check whether module is membrane pipeline