#include <transport_master.h>

Inheritance diagram for ARDOUR::Engine_TransportMaster:

Public Member Functions
	Engine_TransportMaster (AudioEngine &)

	~Engine_TransportMaster ()

void	pre_process (pframes_t nframes, samplepos_t now, std::optional< samplepos_t >)

bool	speed_and_position (double &speed, samplepos_t &pos, samplepos_t &, samplepos_t &, samplepos_t)

bool	starting () const

void	reset (bool with_position)

bool	locked () const

bool	ok () const

bool	usable () const

samplecnt_t	update_interval () const

samplecnt_t	resolution () const

bool	requires_seekahead () const

bool	sample_clock_synced () const

void	init ()

void	check_backend ()

bool	allow_request (TransportRequestSource, TransportRequestType) const

std::string	position_string () const

std::string	delta_string () const

void	create_port ()

Public Member Functions inherited from ARDOUR::TransportMaster
	TransportMaster (SyncSource t, std::string const &name)

virtual	~TransportMaster ()

virtual samplecnt_t	seekahead_distance () const

virtual void	set_sample_clock_synced (bool)

sampleoffset_t	current_delta () const

virtual bool	can_loop () const

virtual Location *	loop_location () const

bool	has_loop () const

SyncSource	type () const

TransportRequestSource	request_type () const

std::string	name () const

void	set_name (std::string const &)

int	set_state (XMLNode const &, int)

XMLNode &	get_state () const

virtual void	set_session (Session *)

std::shared_ptr< Port >	port () const

bool	check_collect ()

virtual void	set_collect (bool)

bool	collect () const

std::string	allowed_request_string () const

TransportRequestType	request_mask () const

void	set_request_mask (TransportRequestType)

bool	removeable () const

void	set_removeable (bool yn)

std::string	display_name (bool sh=true) const

virtual void	unregister_port ()

void	connect_port_using_state ()

Public Member Functions inherited from PBD::Stateful
	Stateful ()

virtual	~Stateful ()

virtual bool	apply_change (PropertyBase const &)

PropertyChange	apply_changes (PropertyList const &)

const OwnedPropertyList &	properties () const

void	add_property (PropertyBase &s)

void	add_extra_xml (XMLNode &)

XMLNode *	extra_xml (const std::string &str, bool add_if_missing=false)

void	save_extra_xml (const XMLNode &)

const PBD::ID &	id () const

bool	set_id (const XMLNode &)

void	set_id (const std::string &)

void	reset_id ()

void	clear_changes ()

virtual void	clear_owned_changes ()

PropertyList *	get_changes_as_properties (PBD::Command *) const

virtual void	rdiff (std::vector< PBD::Command * > &) const

bool	changed () const

virtual PropertyList *	property_factory (const XMLNode &) const

virtual void	suspend_property_changes ()

virtual void	resume_property_changes ()

bool	property_changes_suspended () const

Private Attributes
AudioEngine &	engine

bool	_starting

Additional Inherited Members
Static Public Member Functions inherited from ARDOUR::TransportMaster
static std::shared_ptr< TransportMaster >	factory (SyncSource, std::string const &, bool removeable)

static std::shared_ptr< TransportMaster >	factory (XMLNode const &)

static void	make_property_quarks ()

Public Attributes inherited from PBD::Stateful
PBD::Signal< void(const PropertyChange &)>	PropertyChanged

Static Public Attributes inherited from ARDOUR::TransportMaster
static const std::string	state_node_name

Static Public Attributes inherited from PBD::Stateful
static int	current_state_version

static int	loading_state_version

Protected Member Functions inherited from ARDOUR::TransportMaster
virtual void	connection_handler (std::weak_ptr< ARDOUR::Port >, std::string name1, std::weak_ptr< ARDOUR::Port >, std::string name2, bool yn)

virtual void	register_properties ()

virtual std::string	format_delta_time (sampleoffset_t) const

Protected Member Functions inherited from PBD::Stateful
void	add_instant_xml (XMLNode &, const std::string &directory_path)

XMLNode *	instant_xml (const std::string &str, const std::string &directory_path)

void	add_properties (XMLNode &) const

PropertyChange	set_values (XMLNode const &)

virtual void	post_set (const PropertyChange &)

virtual void	send_change (const PropertyChange &)

virtual void	mid_thaw (const PropertyChange &)

bool	regenerate_xml_or_string_ids () const

Protected Attributes inherited from ARDOUR::TransportMaster
SyncSource	_type

PBD::Property< std::string >	_name

Session *	_session

sampleoffset_t	_current_delta

bool	_pending_collect

bool	_removeable

PBD::Property< TransportRequestType >	_request_mask

PBD::Property< bool >	_sclock_synced

PBD::Property< bool >	_collect

PBD::Property< bool >	_connected

SafeTime	current

int	transport_direction

int	dll_initstate

double	t0

double	t1

double	e2

double	b

double	c

std::shared_ptr< Port >	_port

XMLNode	port_node

PBD::ScopedConnection	port_connection

PBD::ScopedConnection	backend_connection

Protected Attributes inherited from PBD::Stateful
XMLNode *	_extra_xml

XMLNode *	_instant_xml

PBD::PropertyChange	_pending_changed

Glib::Threads::Mutex	_lock

std::string	_xml_node_name
	name of node to use for this object in XML More...

OwnedPropertyList *	_properties

Detailed Description

Definition at line 734 of file transport_master.h.

Constructor & Destructor Documentation

◆ Engine_TransportMaster()

ARDOUR::Engine_TransportMaster::Engine_TransportMaster ( AudioEngine & )

◆ ~Engine_TransportMaster()

ARDOUR::Engine_TransportMaster::~Engine_TransportMaster ( )

Member Function Documentation

◆ allow_request()

bool ARDOUR::Engine_TransportMaster::allow_request	(	TransportRequestSource	,
		TransportRequestType
	)		const

virtual

Reimplemented from ARDOUR::TransportMaster.

◆ check_backend()

void ARDOUR::Engine_TransportMaster::check_backend ( )

virtual

Reimplemented from ARDOUR::TransportMaster.

◆ create_port()

void ARDOUR::Engine_TransportMaster::create_port ( )

inlinevirtual

Implements ARDOUR::TransportMaster.

Definition at line 771 of file transport_master.h.

◆ delta_string()

std::string ARDOUR::Engine_TransportMaster::delta_string ( ) const

virtual

Returns: - current time-delta between engine and sync-source

Reimplemented from ARDOUR::TransportMaster.

◆ init()

void ARDOUR::Engine_TransportMaster::init ( )

virtual

Implements ARDOUR::TransportMaster.

◆ locked()

bool ARDOUR::Engine_TransportMaster::locked ( ) const

virtual

reports to ARDOUR whether the TransportMaster is currently synced to its external time source.

Returns: - when returning false, the transport will stop rolling

Implements ARDOUR::TransportMaster.

◆ ok()

bool ARDOUR::Engine_TransportMaster::ok ( ) const

virtual

reports to ARDOUR whether the slave is in a sane state

Returns: - when returning false, the transport will be stopped and the slave disconnected from ARDOUR.

Implements ARDOUR::TransportMaster.

◆ position_string()

std::string ARDOUR::Engine_TransportMaster::position_string ( ) const

virtual

Implements ARDOUR::TransportMaster.

◆ pre_process()

void ARDOUR::Engine_TransportMaster::pre_process	(	pframes_t	nframes,
		samplepos_t	now,
		std::optional< samplepos_t >
	)

virtual

Implements ARDOUR::TransportMaster.

◆ requires_seekahead()

bool ARDOUR::Engine_TransportMaster::requires_seekahead ( ) const

inlinevirtual

Returns: - when returning true, ARDOUR will wait for seekahead_distance() before transport starts rolling

Implements ARDOUR::TransportMaster.

Definition at line 756 of file transport_master.h.

◆ reset()

void ARDOUR::Engine_TransportMaster::reset ( bool with_position )

virtual

Implements ARDOUR::TransportMaster.

◆ resolution()

samplecnt_t ARDOUR::Engine_TransportMaster::resolution ( ) const

inlinevirtual

Returns: - the timing resolution of the TransportMaster - If the distance of ARDOURs transport to the slave becomes greater than the resolution, sound will stop

Implements ARDOUR::TransportMaster.

Definition at line 752 of file transport_master.h.

◆ sample_clock_synced()

bool ARDOUR::Engine_TransportMaster::sample_clock_synced ( ) const

inlinevirtual

Returns: - when returning true, ARDOUR will use transport speed 1.0 no matter what the slave returns

Reimplemented from ARDOUR::TransportMaster.

Definition at line 760 of file transport_master.h.

◆ speed_and_position()

bool ARDOUR::Engine_TransportMaster::speed_and_position	(	double &	speed,
		samplepos_t &	position,
		samplepos_t &	lp,
		samplepos_t &	when,
		samplepos_t	now
	)

virtual

This is the most important function to implement: Each process cycle, Session::follow_slave will call this method. and after the method call they should

Session::follow_slave will then try to follow the given position using a delay locked loop (DLL), starting with the first given transport speed. If the values of speed and position contradict each other, ARDOUR will always follow the position and disregard the speed. Although, a correct speed is important so that ARDOUR can sync to the master time source quickly.

For background information on delay locked loops, see http://www.kokkinizita.net/papers/usingdll.pdf

The method has the following precondition:

TransportMaster::ok() should return true, otherwise playback will stop immediately and the method will not be called
when the references speed and position are passed into the TransportMaster they are uninitialized

After the method call the following postconditions should be met:

The first position value on transport start should be 0, otherwise ARDOUR will try to locate to the new position rather than move to it
the references speed and position should be assigned to the TransportMasters current requested transport speed and transport position.
TransportMaster::resolution() should be greater than the maximum distance of ARDOURs transport position to the slaves requested transport position.
TransportMaster::locked() should return true, otherwise Session::no_roll will be called
TransportMaster::starting() should be false, otherwise the transport will not move until it becomes true

Parameters

speed	- The transport speed requested
position	- The transport position requested
lp	last position (used for flywheel)
when	last timestamp (used for flywheel)
now	monotonic sample time

Returns: - The return value is currently ignored (see Session::follow_slave)

Reimplemented from ARDOUR::TransportMaster.

◆ starting()

bool ARDOUR::Engine_TransportMaster::starting ( ) const

inlinevirtual

reports to ARDOUR whether the slave is in the process of starting to roll

Returns: - when returning false, transport will not move until this method returns true

Reimplemented from ARDOUR::TransportMaster.

Definition at line 743 of file transport_master.h.

◆ update_interval()

samplecnt_t ARDOUR::Engine_TransportMaster::update_interval ( ) const

virtual

Returns: - the expected update interval for the data source used by this transport master. Even if the data is effectively continuous, this number indicates how long it is between changes to the known position of the master.

Implements ARDOUR::TransportMaster.

◆ usable()

bool ARDOUR::Engine_TransportMaster::usable ( ) const

virtual

reports to ARDOUR whether it is possible to use this slave

Returns: - true if the slave can be used.

Only the JACK ("Engine") slave is ever likely to return false, if JACK is not being used for the Audio/MIDI backend.

Reimplemented from ARDOUR::TransportMaster.

Member Data Documentation

◆ _starting

bool ARDOUR::Engine_TransportMaster::_starting

private

Definition at line 775 of file transport_master.h.

◆ engine

AudioEngine& ARDOUR::Engine_TransportMaster::engine

private

Definition at line 774 of file transport_master.h.

The documentation for this class was generated from the following file:

transport_master.h

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Engine_TransportMaster()

◆ ~Engine_TransportMaster()

Member Function Documentation

◆ allow_request()

◆ check_backend()

◆ create_port()

◆ delta_string()

◆ init()

◆ locked()

◆ ok()

◆ position_string()

◆ pre_process()

◆ requires_seekahead()

◆ reset()

◆ resolution()

◆ sample_clock_synced()

◆ speed_and_position()

◆ starting()

◆ update_interval()

◆ usable()

Member Data Documentation

◆ _starting

◆ engine