Membrane Core v0.1.0 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
Returns a specification to start this module under a supervisor
Checks whether module is a pipeline
Callback implementation for Membrane.Mixins.Playback.playback_warn_error/3
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
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 message incomes from an element
Callback invoked when pipeline receives a message that is not recognized as an internal membrane message
Callback invoked when pipeline is in :playing
state, i.e. all its elements
are in this state
Callback invoked when pipeline is in :prepared
state, i.e. all its elements
are in this state. It receives the previous playback state (:stopped
or
:playing
)
Callback invoked when Membrane.Pipeline.Spec
is linked and in the same playback
state as pipeline
Callback invoked when pipeline is in :playing
state, i.e. all its elements
are in this state
Enables to check whether module is membrane pipeline
Link to this section Types
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() :: Membrane.Mixins.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() :: {:forward, {Membrane.Element.name_t(), Membrane.Message.t()}}
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.
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() :: {: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 happes.
Link to this section Functions
Returns a specification to start this module under a supervisor.
See Supervisor
.
Checks whether module is a pipeline.
Callback implementation for Membrane.Mixins.Playback.playback_warn_error/3
.
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 :: 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_and_terminate(pipeline :: module()) :: :ok
Link to this section Callbacks
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_message( message :: Membrane.Message.t(), element :: Membrane.Element.name_t(), state :: Membrane.Pipeline.State.internal_state_t() ) :: callback_return_t()
Callback invoked when message incomes from an element.
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_play(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_prepare( previous_playback_state :: Membrane.Mixins.Playback.state_t(), state :: Membrane.Pipeline.State.internal_state_t() ) :: callback_return_t()
Callback invoked when pipeline is in :prepared
state, i.e. all its elements
are in this state. It receives the previous playback state (:stopped
or
:playing
).
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_stop(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.
Enables to check whether module is membrane pipeline