#include <slave.h>

Inheritance diagram for ARDOUR::MIDIClock_Slave:

Public Member Functions
	MIDIClock_Slave (Session &, MidiPort &, int ppqn=24)

	MIDIClock_Slave (ISlaveSessionProxy *session_proxy=0, int ppqn=24)
	Constructor for unit tests. More...

	~MIDIClock_Slave ()

void	rebind (MidiPort &)

bool	speed_and_position (double &, framepos_t &)

bool	locked () const

bool	ok () const

bool	starting () const

framecnt_t	resolution () const

bool	requires_seekahead () const

bool	give_slave_full_control_over_transport_speed () const

void	set_bandwidth (double a_bandwith)

std::string	approximate_current_delta () const

Public Member Functions inherited from ARDOUR::Slave
	Slave ()

virtual	~Slave ()

virtual framecnt_t	seekahead_distance () const

virtual bool	is_always_synced () const

Protected Member Functions
void	reset ()

void	start (MIDI::Parser &parser, framepos_t timestamp)

void	contineu (MIDI::Parser &parser, framepos_t timestamp)

void	stop (MIDI::Parser &parser, framepos_t timestamp)

void	position (MIDI::Parser &parser, MIDI::byte *message, size_t size)

void	calculate_one_ppqn_in_frames_at (framepos_t time)

framepos_t	calculate_song_position (uint16_t song_position_in_sixteenth_notes)

void	calculate_filter_coefficients ()

void	update_midi_clock (MIDI::Parser &parser, framepos_t timestamp)

void	read_current (SafeTime *) const

bool	stop_if_no_more_clock_events (framepos_t &pos, framepos_t now)

Protected Attributes
ISlaveSessionProxy *	session

PBD::ScopedConnectionList	port_connections

int	ppqn
	pulses per quarter note for one MIDI clock frame (default 24) More...

double	one_ppqn_in_frames
	the duration of one ppqn in frame time More...

framepos_t	first_timestamp
	the timestamp of the first MIDI clock message More...

framepos_t	last_timestamp
	the time stamp and should-be transport position of the last inbound MIDI clock message More...

double	should_be_position

long	midi_clock_count

double	t0
	time at the beginning of the MIDI clock frame More...

double	t1
	calculated end of the MIDI clock frame More...

double	e
	loop error = real value - expected value More...

double	e2
	second order loop error More...

double	bandwidth
	DLL filter bandwidth. More...

double	b
	DLL filter coefficients. More...

double	c

double	omega

frameoffset_t	current_delta

bool	_started
	whether transport should be rolling More...

bool	_starting

Detailed Description

Definition at line 408 of file slave.h.

Constructor & Destructor Documentation

MIDIClock_Slave::MIDIClock_Slave	(	Session &	s,
		MidiPort &	p,
		int	ppqn = `24`
	)

Definition at line 45 of file midi_clock_slave.cc.

MIDIClock_Slave::MIDIClock_Slave	(	ISlaveSessionProxy *	session_proxy = `0`,
		int	ppqn = `24`
	)

Constructor for unit tests.

Definition at line 54 of file midi_clock_slave.cc.

MIDIClock_Slave::~MIDIClock_Slave ( )

Definition at line 62 of file midi_clock_slave.cc.

Member Function Documentation

std::string MIDIClock_Slave::approximate_current_delta ( ) const

virtual

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

Reimplemented from ARDOUR::Slave.

Definition at line 368 of file midi_clock_slave.cc.

void MIDIClock_Slave::calculate_filter_coefficients ( )

protected

Definition at line 109 of file midi_clock_slave.cc.

void MIDIClock_Slave::calculate_one_ppqn_in_frames_at ( framepos_t time )

protected

Definition at line 83 of file midi_clock_slave.cc.

ARDOUR::framepos_t MIDIClock_Slave::calculate_song_position ( uint16_t song_position_in_sixteenth_notes )

protected

Definition at line 96 of file midi_clock_slave.cc.

void MIDIClock_Slave::contineu	(	MIDI::Parser &	parser,
		framepos_t	timestamp
	)

protected

Definition at line 221 of file midi_clock_slave.cc.

bool ARDOUR::MIDIClock_Slave::give_slave_full_control_over_transport_speed ( ) const

inlinevirtual

Returns: - whether ARDOUR should use the slave speed without any adjustments

Reimplemented from ARDOUR::Slave.

Definition at line 425 of file slave.h.

bool MIDIClock_Slave::locked ( ) const

virtual

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

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

Implements ARDOUR::Slave.

Definition at line 288 of file midi_clock_slave.cc.

bool MIDIClock_Slave::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::Slave.

Definition at line 294 of file midi_clock_slave.cc.

void MIDIClock_Slave::position	(	MIDI::Parser &	parser,
		MIDI::byte *	message,
		size_t	size
	)

protected

Definition at line 263 of file midi_clock_slave.cc.

void ARDOUR::MIDIClock_Slave::read_current ( SafeTime * ) const

protected

void MIDIClock_Slave::rebind ( MidiPort & port )

Definition at line 68 of file midi_clock_slave.cc.

bool ARDOUR::MIDIClock_Slave::requires_seekahead ( ) const

inlinevirtual

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

Implements ARDOUR::Slave.

Definition at line 424 of file slave.h.

void MIDIClock_Slave::reset ( )

protected

Definition at line 206 of file midi_clock_slave.cc.

ARDOUR::framecnt_t MIDIClock_Slave::resolution ( ) const

virtual

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

Implements ARDOUR::Slave.

Definition at line 361 of file midi_clock_slave.cc.

void ARDOUR::MIDIClock_Slave::set_bandwidth ( double a_bandwith )

inline

Definition at line 427 of file slave.h.

bool MIDIClock_Slave::speed_and_position	(	double &	speed,
		framepos_t &	position
	)

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:

Slave::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 Slave 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 Slaves current requested transport speed and transport position.
Slave::resolution() should be greater than the maximum distance of ARDOURs transport position to the slaves requested transport position.
Slave::locked() should return true, otherwise Session::no_roll will be called
Slave::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

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

Implements ARDOUR::Slave.

Definition at line 323 of file midi_clock_slave.cc.

void MIDIClock_Slave::start	(	MIDI::Parser &	parser,
		framepos_t	timestamp
	)

protected

Definition at line 191 of file midi_clock_slave.cc.

bool MIDIClock_Slave::starting ( ) const

virtual

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::Slave.

Definition at line 300 of file midi_clock_slave.cc.

void MIDIClock_Slave::stop	(	MIDI::Parser &	parser,
		framepos_t	timestamp
	)

protected

Definition at line 233 of file midi_clock_slave.cc.

bool MIDIClock_Slave::stop_if_no_more_clock_events	(	framepos_t &	pos,
		framepos_t	now
	)

protected

Definition at line 306 of file midi_clock_slave.cc.

void MIDIClock_Slave::update_midi_clock	(	MIDI::Parser &	parser,
		framepos_t	timestamp
	)

protected

Definition at line 118 of file midi_clock_slave.cc.

Member Data Documentation

bool ARDOUR::MIDIClock_Slave::_started

protected

whether transport should be rolling

Definition at line 487 of file slave.h.

bool ARDOUR::MIDIClock_Slave::_starting

protected

is true if the MIDI Start message has just been received until the first MIDI Clock Event

Definition at line 491 of file slave.h.

double ARDOUR::MIDIClock_Slave::b

protected

DLL filter coefficients.

Definition at line 469 of file slave.h.

double ARDOUR::MIDIClock_Slave::bandwidth

protected

DLL filter bandwidth.

Definition at line 466 of file slave.h.

double ARDOUR::MIDIClock_Slave::c

protected

Definition at line 469 of file slave.h.

frameoffset_t ARDOUR::MIDIClock_Slave::current_delta

protected

Definition at line 471 of file slave.h.

double ARDOUR::MIDIClock_Slave::e

protected

loop error = real value - expected value

Definition at line 460 of file slave.h.

double ARDOUR::MIDIClock_Slave::e2

protected

second order loop error

Definition at line 463 of file slave.h.

framepos_t ARDOUR::MIDIClock_Slave::first_timestamp

protected

the timestamp of the first MIDI clock message

Definition at line 441 of file slave.h.

framepos_t ARDOUR::MIDIClock_Slave::last_timestamp

protected

the time stamp and should-be transport position of the last inbound MIDI clock message

Definition at line 444 of file slave.h.

long ARDOUR::MIDIClock_Slave::midi_clock_count

protected

the number of midi clock messages received (zero-based) since start

Definition at line 449 of file slave.h.

double ARDOUR::MIDIClock_Slave::omega

protected

Definition at line 469 of file slave.h.

double ARDOUR::MIDIClock_Slave::one_ppqn_in_frames

protected

the duration of one ppqn in frame time

Definition at line 438 of file slave.h.

PBD::ScopedConnectionList ARDOUR::MIDIClock_Slave::port_connections

protected

Definition at line 432 of file slave.h.

int ARDOUR::MIDIClock_Slave::ppqn

protected

pulses per quarter note for one MIDI clock frame (default 24)

Definition at line 435 of file slave.h.

ISlaveSessionProxy* ARDOUR::MIDIClock_Slave::session

protected

Definition at line 431 of file slave.h.

double ARDOUR::MIDIClock_Slave::should_be_position

protected

Definition at line 445 of file slave.h.

double ARDOUR::MIDIClock_Slave::t0

protected

time at the beginning of the MIDI clock frame

Definition at line 454 of file slave.h.

double ARDOUR::MIDIClock_Slave::t1

protected

calculated end of the MIDI clock frame

Definition at line 457 of file slave.h.

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

/usr/local/music/src/ardour/4.0/libs/ardour/ardour/slave.h
/usr/local/music/src/ardour/4.0/libs/ardour/midi_clock_slave.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation