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ardour/libs/ardour/ardour/slave.h

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/*
Copyright (C) 2002 Paul Davis
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __ardour_slave_h__
#define __ardour_slave_h__
#include <vector>
#include <glibmm/threads.h>
#include <ltc.h>
#include "pbd/signals.h"
#include "temporal/time.h"
#include "ardour/libardour_visibility.h"
#include "ardour/types.h"
#include "midi++/parser.h"
#include "midi++/types.h"
/* used for approximate_current_delta(): */
#define PLUSMINUS(A) ( ((A)<0) ? "-" : (((A)>0) ? "+" : "\u00B1") )
#define LEADINGZERO(A) ( (A)<10 ? " " : (A)<100 ? " " : (A)<1000 ? " " : "" )
namespace ARDOUR {
class TempoMap;
class Session;
class AudioEngine;
class MidiPort;
/**
* @class Slave
*
* @brief The Slave interface can be used to sync ARDOURs tempo to an external source
* like MTC, MIDI Clock, etc.
*
* The name of the interface may be a bit misleading: A subclass of Slave actually
* acts as a time master for ARDOUR, that means ARDOUR will try to follow the
* speed and transport position of the implementation of Slave.
* Therefore it is rather that class, that makes ARDOUR a slave by connecting it
* to its external time master.
*/
class LIBARDOUR_API Slave {
public:
Slave() { }
virtual ~Slave() {}
/**
* 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
* <em>position</em> 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:
* <ul>
* <li>
* Slave::ok() should return true, otherwise playback will stop
* immediately and the method will not be called
* </li>
* <li>
* when the references speed and position are passed into the Slave
* they are uninitialized
* </li>
* </ul>
*
* After the method call the following postconditions should be met:
* <ul>
* <li>
* 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
* </li>
* <li>
* the references speed and position should be assigned
* to the Slaves current requested transport speed
* and transport position.
* </li>
* <li>
* Slave::resolution() should be greater than the maximum distance of
* ARDOURs transport position to the slaves requested transport position.
* </li>
* <li>Slave::locked() should return true, otherwise Session::no_roll will be called</li>
* <li>Slave::starting() should be false, otherwise the transport will not move until it becomes true</li> *
* </ul>
*
* @param speed - The transport speed requested
* @param position - The transport position requested
* @return - The return value is currently ignored (see Session::follow_slave)
*/
virtual bool speed_and_position (double& speed, samplepos_t& position) = 0;
/**
* reports to ARDOUR whether the Slave is currently synced to its external
* time source.
*
* @return - when returning false, the transport will stop rolling
*/
virtual bool locked() const = 0;
/**
* reports to ARDOUR whether the slave is in a sane state
*
* @return - when returning false, the transport will be stopped and the slave
* disconnected from ARDOUR.
*/
virtual bool ok() const = 0;
/**
* reports to ARDOUR whether the slave is in the process of starting
* to roll
*
* @return - when returning false, transport will not move until this method returns true
*/
virtual bool starting() const { return false; }
/**
* @return - the timing resolution of the Slave - If the distance of ARDOURs transport
* to the slave becomes greater than the resolution, sound will stop
*/
virtual samplecnt_t resolution() const = 0;
/**
* @return - when returning true, ARDOUR will wait for seekahead_distance() before transport
* starts rolling
*/
virtual bool requires_seekahead () const = 0;
/**
* @return the number of samples that this slave wants to seek ahead. Relevant
* only if requires_seekahead() returns true.
*/
virtual samplecnt_t seekahead_distance() const { return 0; }
/**
* @return - when returning true, ARDOUR will use transport speed 1.0 no matter what
* the slave returns
*/
virtual bool is_always_synced() const { return false; }
/**
* @return - whether ARDOUR should use the slave speed without any adjustments
*/
virtual bool give_slave_full_control_over_transport_speed() const { return false; }
/**
* @return - current time-delta between engine and sync-source
*/
virtual std::string approximate_current_delta() const { return ""; }
};
/// We need this wrapper for testability, it's just too hard to mock up a session class
class LIBARDOUR_API ISlaveSessionProxy {
public:
virtual ~ISlaveSessionProxy() {}
virtual TempoMap& tempo_map() const { return *((TempoMap *) 0); }
virtual samplecnt_t sample_rate() const { return 0; }
virtual pframes_t samples_per_cycle() const { return 0; }
virtual samplepos_t audible_sample () const { return 0; }
virtual samplepos_t transport_sample () const { return 0; }
virtual pframes_t samples_since_cycle_start () const { return 0; }
virtual samplepos_t sample_time_at_cycle_start() const { return 0; }
virtual samplepos_t sample_time () const { return 0; }
virtual void request_locate (samplepos_t /*sample*/, bool with_roll = false) {
(void) with_roll;
}
virtual void request_transport_speed (double /*speed*/) {}
};
/// The Session Proxy for use in real Ardour
class LIBARDOUR_API SlaveSessionProxy : public ISlaveSessionProxy {
Session& session;
public:
SlaveSessionProxy(Session &s) : session(s) {}
TempoMap& tempo_map() const;
samplecnt_t sample_rate() const;
pframes_t samples_per_cycle() const;
samplepos_t audible_sample () const;
samplepos_t transport_sample () const;
pframes_t samples_since_cycle_start () const;
samplepos_t sample_time_at_cycle_start() const;
samplepos_t sample_time () const;
void request_locate (samplepos_t sample, bool with_roll = false);
void request_transport_speed (double speed);
};
struct LIBARDOUR_API SafeTime {
volatile int guard1;
samplepos_t position;
samplepos_t timestamp;
double speed;
volatile int guard2;
SafeTime() {
guard1 = 0;
position = 0;
timestamp = 0;
speed = 0;
guard2 = 0;
}
};
class LIBARDOUR_API TimecodeSlave : public Slave {
public:
TimecodeSlave () {}
virtual Timecode::TimecodeFormat apparent_timecode_format() const = 0;
/* this is intended to be used by a UI and polled from a timeout. it should
return a string describing the current position of the TC source. it
should NOT do any computation, but should use a cached value
of the TC source position.
*/
virtual std::string approximate_current_position() const = 0;
samplepos_t timecode_offset;
bool timecode_negative_offset;
PBD::Signal1<void, bool> ActiveChanged;
};
class LIBARDOUR_API MTC_Slave : public TimecodeSlave {
public:
MTC_Slave (Session&, MidiPort&);
~MTC_Slave ();
void rebind (MidiPort&);
bool speed_and_position (double&, samplepos_t&);
bool locked() const;
bool ok() const;
void handle_locate (const MIDI::byte*);
samplecnt_t resolution () const;
bool requires_seekahead () const { return false; }
samplecnt_t seekahead_distance() const;
bool give_slave_full_control_over_transport_speed() const;
Timecode::TimecodeFormat apparent_timecode_format() const;
std::string approximate_current_position() const;
std::string approximate_current_delta() const;
private:
Session& session;
MidiPort* port;
PBD::ScopedConnectionList port_connections;
PBD::ScopedConnection config_connection;
bool can_notify_on_unknown_rate;
static const int sample_tolerance;
SafeTime current;
samplepos_t mtc_frame; /* current time */
double mtc_frame_dll;
samplepos_t last_inbound_frame; /* when we got it; audio clocked */
MIDI::byte last_mtc_fps_byte;
samplepos_t window_begin;
samplepos_t window_end;
samplepos_t first_mtc_timestamp;
bool did_reset_tc_format;
Timecode::TimecodeFormat saved_tc_format;
Glib::Threads::Mutex reset_lock;
uint32_t reset_pending;
bool reset_position;
int transport_direction;
int busy_guard1;
int busy_guard2;
double speedup_due_to_tc_mismatch;
double quarter_frame_duration;
Timecode::TimecodeFormat mtc_timecode;
Timecode::TimecodeFormat a3e_timecode;
Timecode::Time timecode;
bool printed_timecode_warning;
sampleoffset_t current_delta;
/* DLL - chase MTC */
double t0; ///< time at the beginning of the MTC quater sample
double t1; ///< calculated end of the MTC quater sample
double e2; ///< second order loop error
double b, c, omega; ///< DLL filter coefficients
/* DLL - sync engine */
int engine_dll_initstate;
double te0; ///< time at the beginning of the engine process
double te1; ///< calculated sync time
double ee2; ///< second order loop error
double be, ce, oe; ///< DLL filter coefficients
void reset (bool with_pos);
void queue_reset (bool with_pos);
void maybe_reset ();
void update_mtc_qtr (MIDI::Parser&, int, samplepos_t);
void update_mtc_time (const MIDI::byte *, bool, samplepos_t);
void update_mtc_status (MIDI::MTC_Status);
void read_current (SafeTime *) const;
void reset_window (samplepos_t);
bool outside_window (samplepos_t) const;
void init_mtc_dll(samplepos_t, double);
void init_engine_dll (samplepos_t, samplepos_t);
void parse_timecode_offset();
void parameter_changed(std::string const & p);
};
class LIBARDOUR_API LTC_Slave : public TimecodeSlave {
public:
LTC_Slave (Session&);
~LTC_Slave ();
bool speed_and_position (double&, samplepos_t&);
bool locked() const;
bool ok() const;
samplecnt_t resolution () const;
bool requires_seekahead () const { return false; }
samplecnt_t seekahead_distance () const { return 0; }
bool give_slave_full_control_over_transport_speed() const { return true; }
Timecode::TimecodeFormat apparent_timecode_format() const;
std::string approximate_current_position() const;
std::string approximate_current_delta() const;
private:
void parse_ltc(const pframes_t, const Sample* const, const samplecnt_t);
void process_ltc(samplepos_t const);
void init_engine_dll (samplepos_t, int32_t);
bool detect_discontinuity(LTCFrameExt *, int, bool);
bool detect_ltc_fps(int, bool);
bool equal_ltc_sample_time(LTCFrame *a, LTCFrame *b);
void reset (bool with_ts = true);
void resync_xrun();
void resync_latency();
void parse_timecode_offset();
void parameter_changed(std::string const & p);
Session& session;
bool did_reset_tc_format;
Timecode::TimecodeFormat saved_tc_format;
LTCDecoder * decoder;
double samples_per_ltc_frame;
Timecode::Time timecode;
LTCFrameExt prev_sample;
bool fps_detected;
samplecnt_t monotonic_cnt;
samplecnt_t last_timestamp;
samplecnt_t last_ltc_sample;
double ltc_speed;
sampleoffset_t current_delta;
int delayedlocked;
int ltc_detect_fps_cnt;
int ltc_detect_fps_max;
bool printed_timecode_warning;
bool sync_lock_broken;
Timecode::TimecodeFormat ltc_timecode;
Timecode::TimecodeFormat a3e_timecode;
PBD::ScopedConnectionList port_connections;
PBD::ScopedConnection config_connection;
LatencyRange ltc_slave_latency;
/* DLL - chase LTC */
int transport_direction;
int engine_dll_initstate;
double t0; ///< time at the beginning of the MTC quater sample
double t1; ///< calculated end of the MTC quater sample
double e2; ///< second order loop error
double b, c; ///< DLL filter coefficients
};
class LIBARDOUR_API MIDIClock_Slave : public Slave {
public:
MIDIClock_Slave (Session&, MidiPort&, int ppqn = 24);
/// Constructor for unit tests
MIDIClock_Slave (ISlaveSessionProxy* session_proxy = 0, int ppqn = 24);
~MIDIClock_Slave ();
void rebind (MidiPort&);
bool speed_and_position (double&, samplepos_t&);
bool locked() const;
bool ok() const;
bool starting() const;
samplecnt_t resolution () const;
bool requires_seekahead () const { return false; }
bool give_slave_full_control_over_transport_speed() const { return true; }
void set_bandwidth (double a_bandwith) { bandwidth = a_bandwith; }
std::string approximate_current_delta() const;
protected:
ISlaveSessionProxy* session;
PBD::ScopedConnectionList port_connections;
/// pulses per quarter note for one MIDI clock sample (default 24)
int ppqn;
/// the duration of one ppqn in sample time
double one_ppqn_in_samples;
/// the timestamp of the first MIDI clock message
samplepos_t first_timestamp;
/// the time stamp and should-be transport position of the last inbound MIDI clock message
samplepos_t last_timestamp;
double should_be_position;
/// the number of midi clock messages received (zero-based)
/// since start
long midi_clock_count;
//the delay locked loop (DLL), see www.kokkinizita.net/papers/usingdll.pdf
/// time at the beginning of the MIDI clock sample
double t0;
/// calculated end of the MIDI clock sample
double t1;
/// loop error = real value - expected value
double e;
/// second order loop error
double e2;
/// DLL filter bandwidth
double bandwidth;
/// DLL filter coefficients
double b, c, omega;
sampleoffset_t current_delta;
void reset ();
void start (MIDI::Parser& parser, samplepos_t timestamp);
void contineu (MIDI::Parser& parser, samplepos_t timestamp);
void stop (MIDI::Parser& parser, samplepos_t timestamp);
void position (MIDI::Parser& parser, MIDI::byte* message, size_t size);
// we can't use continue because it is a C++ keyword
void calculate_one_ppqn_in_samples_at(samplepos_t time);
samplepos_t calculate_song_position(uint16_t song_position_in_sixteenth_notes);
void calculate_filter_coefficients();
void update_midi_clock (MIDI::Parser& parser, samplepos_t timestamp);
void read_current (SafeTime *) const;
bool stop_if_no_more_clock_events(samplepos_t& pos, samplepos_t now);
/// whether transport should be rolling
bool _started;
/// is true if the MIDI Start message has just been received until
/// the first MIDI Clock Event
bool _starting;
};
class LIBARDOUR_API Engine_Slave : public Slave
{
public:
Engine_Slave (AudioEngine&);
~Engine_Slave ();
bool speed_and_position (double& speed, samplepos_t& pos);
bool starting() const { return _starting; }
bool locked() const;
bool ok() const;
samplecnt_t resolution () const { return 1; }
bool requires_seekahead () const { return false; }
bool is_always_synced() const { return true; }
private:
AudioEngine& engine;
bool _starting;
};
} /* namespace */
#endif /* __ardour_slave_h__ */
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