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livetrax/libs/ardour/midi_clock_slave.cc
Carl Hetherington 1238f09478 Use DEBUG_TRACE for all of the MIDI clock ticker code.
git-svn-id: svn://localhost/ardour2/branches/3.0@8264 d708f5d6-7413-0410-9779-e7cbd77b26cf
2010-12-14 01:05:51 +00:00

363 lines
10 KiB
C++

/*
Copyright (C) 2008 Paul Davis
Author: Hans Baier
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.
*/
#include <cmath>
#include <errno.h>
#include <poll.h>
#include <sys/types.h>
#include <unistd.h>
#include "pbd/error.h"
#include "pbd/failed_constructor.h"
#include "pbd/pthread_utils.h"
#include "midi++/port.h"
#include "ardour/debug.h"
#include "ardour/slave.h"
#include "ardour/session.h"
#include "ardour/audioengine.h"
#include "ardour/cycles.h"
#include "ardour/tempo.h"
#include "i18n.h"
using namespace std;
using namespace ARDOUR;
using namespace MIDI;
using namespace PBD;
MIDIClock_Slave::MIDIClock_Slave (Session& s, MIDI::Port& p, int ppqn)
: ppqn (ppqn)
, bandwidth (1.0 / 60.0) // 1 BpM = 1 / 60 Hz
{
session = (ISlaveSessionProxy *) new SlaveSessionProxy(s);
rebind (p);
reset ();
}
MIDIClock_Slave::MIDIClock_Slave (ISlaveSessionProxy* session_proxy, int ppqn)
: session(session_proxy)
, ppqn (ppqn)
, bandwidth (1.0 / 60.0) // 1 BpM = 1 / 60 Hz
{
reset ();
}
MIDIClock_Slave::~MIDIClock_Slave()
{
delete session;
}
void
MIDIClock_Slave::rebind (MIDI::Port& p)
{
port_connections.drop_connections();
port = &p;
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave: connecting to port %1\n", port->name()));
port->parser()->timing.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::update_midi_clock, this, _1, _2));
port->parser()->start.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::start, this, _1, _2));
port->parser()->contineu.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::contineu, this, _1, _2));
port->parser()->stop.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::stop, this, _1, _2));
port->parser()->position.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::position, this, _1, _2, 3));
}
void
MIDIClock_Slave::calculate_one_ppqn_in_frames_at(framepos_t time)
{
const Tempo& current_tempo = session->tempo_map().tempo_at(time);
const Meter& current_meter = session->tempo_map().meter_at(time);
double frames_per_beat =
current_tempo.frames_per_beat(session->frame_rate(),
current_meter);
double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
one_ppqn_in_frames = frames_per_quarter_note / double (ppqn);
// DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_frames));
}
ARDOUR::framepos_t
MIDIClock_Slave::calculate_song_position(uint16_t song_position_in_sixteenth_notes)
{
framepos_t song_position_frames = 0;
for (uint16_t i = 1; i <= song_position_in_sixteenth_notes; ++i) {
// one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
calculate_one_ppqn_in_frames_at(song_position_frames);
song_position_frames += one_ppqn_in_frames * (framepos_t)(ppqn / 4);
}
return song_position_frames;
}
void
MIDIClock_Slave::calculate_filter_coefficients()
{
// omega = 2 * PI * Bandwidth / MIDI clock frame frequency in Hz
omega = 2.0 * M_PI * bandwidth * one_ppqn_in_frames / session->frame_rate();
b = 1.4142135623730950488 * omega;
c = omega * omega;
}
void
MIDIClock_Slave::update_midi_clock (Parser& /*parser*/, framepos_t timestamp)
{
// some pieces of hardware send MIDI Clock all the time
if ( (!_starting) && (!_started) ) {
return;
}
calculate_one_ppqn_in_frames_at(should_be_position);
framepos_t elapsed_since_start = timestamp - first_timestamp;
double error = 0;
if (_starting || last_timestamp == 0) {
midi_clock_count = 0;
first_timestamp = timestamp;
elapsed_since_start = should_be_position;
// calculate filter coefficients
calculate_filter_coefficients();
// initialize DLL
e2 = double(one_ppqn_in_frames) / double(session->frame_rate());
t0 = double(elapsed_since_start) / double(session->frame_rate());
t1 = t0 + e2;
// let ardour go after first MIDI Clock Event
_starting = false;
} else {
midi_clock_count++;
should_be_position += one_ppqn_in_frames;
calculate_filter_coefficients();
// calculate loop error
// we use session->audible_frame() instead of t1 here
// because t1 is used to calculate the transport speed,
// so the loop will compensate for accumulating rounding errors
error = (double(should_be_position) - double(session->audible_frame()));
e = error / double(session->frame_rate());
// update DLL
t0 = t1;
t1 += b * e + e2;
e2 += c * e;
}
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 arrived %3 (theoretical) audible %4 transport %5 error %6 "
"read delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 appspeed %13\n",
midi_clock_count,
elapsed_since_start,
should_be_position,
session->audible_frame(),
session->transport_frame(),
error,
timestamp - last_timestamp,
one_ppqn_in_frames,
(t1 -t0) * session->frame_rate(),
t0 * session->frame_rate(),
t1 * session->frame_rate(),
session->frame_rate(),
((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames));
last_timestamp = timestamp;
}
void
MIDIClock_Slave::start (Parser& /*parser*/, framepos_t timestamp)
{
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave got start message at time %1 engine time %2\n", timestamp, session->frame_time()));
if (!_started) {
reset();
_started = true;
_starting = true;
should_be_position = session->transport_frame();
}
}
void
MIDIClock_Slave::reset ()
{
should_be_position = session->transport_frame();
last_timestamp = 0;
_starting = true;
_started = true;
// session->request_locate(0, false);
}
void
MIDIClock_Slave::contineu (Parser& /*parser*/, framepos_t /*timestamp*/)
{
DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got continue message\n");
if (!_started) {
_starting = true;
_started = true;
}
}
void
MIDIClock_Slave::stop (Parser& /*parser*/, framepos_t /*timestamp*/)
{
DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got stop message\n");
if (_started || _starting) {
_starting = false;
_started = false;
// locate to last MIDI clock position
session->request_transport_speed(0.0);
// we need to go back to the last MIDI beat (6 ppqn)
// and lets hope the tempo didnt change in the meantime :)
// begin at the should be position, because
// that is the position of the last MIDI Clock
// message and that is probably what the master
// expects where we are right now
framepos_t stop_position = should_be_position;
// find out the last MIDI beat: go back #midi_clocks mod 6
// and lets hope the tempo didnt change in those last 6 beats :)
stop_position -= (midi_clock_count % 6) * one_ppqn_in_frames;
session->request_locate(stop_position, false);
should_be_position = stop_position;
last_timestamp = 0;
}
}
void
MIDIClock_Slave::position (Parser& /*parser*/, byte* message, size_t size)
{
// we are note supposed to get position messages while we are running
// so lets be robust and ignore those
if (_started || _starting) {
return;
}
assert(size == 3);
byte lsb = message[1];
byte msb = message[2];
assert((lsb <= 0x7f) && (msb <= 0x7f));
uint16_t position_in_sixteenth_notes = (uint16_t(msb) << 7) | uint16_t(lsb);
framepos_t position_in_frames = calculate_song_position(position_in_sixteenth_notes);
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 frames: %2\n", position_in_sixteenth_notes, position_in_frames));
session->request_locate(position_in_frames, false);
should_be_position = position_in_frames;
last_timestamp = 0;
}
bool
MIDIClock_Slave::locked () const
{
return true;
}
bool
MIDIClock_Slave::ok() const
{
return true;
}
bool
MIDIClock_Slave::starting() const
{
return false;
}
bool
MIDIClock_Slave::stop_if_no_more_clock_events(framepos_t& pos, framepos_t now)
{
/* no timecode for 1/4 second ? conclude that its stopped */
if (last_timestamp &&
now > last_timestamp &&
now - last_timestamp > session->frame_rate() / 4) {
DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock frames received for some time, stopping!\n");
pos = should_be_position;
session->request_transport_speed (0);
session->request_locate (should_be_position, false);
return true;
} else {
return false;
}
}
bool
MIDIClock_Slave::speed_and_position (double& speed, framepos_t& pos)
{
if (!_started || _starting) {
speed = 0.0;
pos = should_be_position;
return true;
}
framepos_t engine_now = session->frame_time();
if (stop_if_no_more_clock_events(pos, engine_now)) {
return false;
}
// calculate speed
speed = ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames;
// provide a 3% deadzone to lock the speed
if (fabs(speed - 1.0) <= 0.03)
speed = 1.0;
// calculate position
if (engine_now > last_timestamp) {
// we are in between MIDI clock messages
// so we interpolate position according to speed
framecnt_t elapsed = engine_now - last_timestamp;
pos = (framepos_t) (should_be_position + double(elapsed) * speed);
} else {
// A new MIDI clock message has arrived this cycle
pos = should_be_position;
}
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("speed_and_position: %1 & %2 <-> %3 (transport)\n", speed, pos, session->transport_frame()));
return true;
}
ARDOUR::framecnt_t
MIDIClock_Slave::resolution() const
{
// one beat
return (framecnt_t) one_ppqn_in_frames * ppqn;
}