libardour added.

git-svn-id: svn://localhost/trunk/ardour2@17 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 1115 insertions, 0 deletions

diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
new file mode 100644
index 0000000000..2792bd5e65
--- /dev/null
+++ b/libs/ardour/audioengine.cc
@@ -0,0 +1,1115 @@
+/*
+    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.
+
+    $Id$
+*/
+
+#include <unistd.h>
+#include <cerrno>
+#include <vector>
+#include <pbd/pthread_utils.h>
+
+#include <ardour/audioengine.h>
+#include <ardour/port.h>
+#include <ardour/session.h>
+#include <ardour/cycle_timer.h>
+#include <ardour/utils.h>
+#ifdef VST_SUPPORT
+#include <fst.h>
+#endif
+
+#include <ardour/timestamps.h>
+
+#include "i18n.h"
+
+using namespace std;
+using namespace ARDOUR;
+
+jack_nframes_t Port::short_over_length = 2;
+jack_nframes_t Port::long_over_length = 10;
+
+AudioEngine::AudioEngine (string client_name) 
+{
+	pthread_cond_init (&session_removed, 0);
+	session = 0;
+	session_remove_pending = false;
+	_running = false;
+	_has_run = false;
+	last_monitor_check = 0;
+	monitor_check_interval = max_frames;
+	_processed_frames = 0;
+	_freewheeling = false;
+	_usecs_per_cycle = 0;
+	_jack = 0;
+	_frame_rate = 0;
+	_buffer_size = 0;
+	_freewheeling = false;
+	_freewheel_thread_registered = false;
+
+	if (connect_to_jack (client_name)) {
+		throw NoBackendAvailable ();
+	}
+
+}
+
+AudioEngine::~AudioEngine ()
+{
+	if (_running) {
+		jack_client_close (_jack);
+	}
+}
+
+void
+_thread_init_callback (void *arg)
+{
+	/* make sure that anybody who needs to know about this thread
+	   knows about it.
+	*/
+
+	PBD::ThreadCreated (pthread_self(), X_("Audioengine"));
+
+#ifdef VST_SUPPORT
+	if (Config->get_use_vst()) {
+		fst_adopt_thread ();
+	}
+#endif
+}
+
+int
+AudioEngine::start ()
+{
+	if (!_running) {
+
+		if (session) {
+			jack_nframes_t blocksize = jack_get_buffer_size (_jack);
+
+			session->set_block_size (blocksize);
+			session->set_frame_rate (jack_get_sample_rate (_jack));
+
+			/* page in as much of the session process code as we
+			   can before we really start running.
+			*/
+
+			session->process (blocksize);
+			session->process (blocksize);
+			session->process (blocksize);
+			session->process (blocksize);
+			session->process (blocksize);
+			session->process (blocksize);
+			session->process (blocksize);
+			session->process (blocksize);
+		}
+
+		_processed_frames = 0;
+		last_monitor_check = 0;
+
+		jack_on_shutdown (_jack, halted, this);
+		jack_set_graph_order_callback (_jack, _graph_order_callback, this);
+		jack_set_thread_init_callback (_jack, _thread_init_callback, this);
+		jack_set_process_callback (_jack, _process_callback, this);
+		jack_set_sample_rate_callback (_jack, _sample_rate_callback, this);
+		jack_set_buffer_size_callback (_jack, _bufsize_callback, this);
+		jack_set_xrun_callback (_jack, _xrun_callback, this);
+		jack_set_sync_callback (_jack, _jack_sync_callback, this);
+		jack_set_freewheel_callback (_jack, _freewheel_callback, this);
+
+		if (Config->get_jack_time_master()) {
+			jack_set_timebase_callback (_jack, 0, _jack_timebase_callback, this);
+		}
+
+		if (jack_activate (_jack) == 0) {
+			_running = true;
+			_has_run = true;
+			Running(); /* EMIT SIGNAL */
+		} else {
+			error << _("cannot activate JACK client") << endmsg;
+		}
+	}
+
+	return _running ? 0 : -1;
+}
+
+int
+AudioEngine::stop ()
+{
+	if (_running) {
+		_running = false;
+		jack_deactivate (_jack);
+		Stopped(); /* EMIT SIGNAL */
+	}
+
+	return _running ? -1 : 0;
+}
+
+
+void
+AudioEngine::_jack_timebase_callback (jack_transport_state_t state, jack_nframes_t nframes,
+
+									  jack_position_t* pos, int new_position, void *arg)
+{
+	static_cast<AudioEngine*> (arg)->jack_timebase_callback (state, nframes, pos, new_position);
+}
+
+void
+AudioEngine::jack_timebase_callback (jack_transport_state_t state, jack_nframes_t nframes,
+
+									 jack_position_t* pos, int new_position)
+{
+	if (session && session->synced_to_jack()) {
+		session->jack_timebase_callback (state, nframes, pos, new_position);
+	}
+}
+
+int
+AudioEngine::_jack_sync_callback (jack_transport_state_t state, jack_position_t* pos, void* arg)
+{
+	return static_cast<AudioEngine*> (arg)->jack_sync_callback (state, pos);
+}
+
+int
+AudioEngine::jack_sync_callback (jack_transport_state_t state, jack_position_t* pos)
+{
+	if (session) {
+		return session->jack_sync_callback (state, pos);
+	} else {
+		return true;
+	}
+}
+
+int
+AudioEngine::_xrun_callback (void *arg)
+{
+	 static_cast<AudioEngine *>(arg)->Xrun (); /* EMIT SIGNAL */
+	return 0;
+}
+
+int
+AudioEngine::_graph_order_callback (void *arg)
+{
+	 static_cast<AudioEngine *>(arg)->GraphReordered (); /* EMIT SIGNAL */
+	return 0;
+}
+
+int
+AudioEngine::_process_callback (jack_nframes_t nframes, void *arg)
+{
+	return static_cast<AudioEngine *> (arg)->process_callback (nframes);
+}
+
+void
+AudioEngine::_freewheel_callback (int onoff, void *arg)
+{
+	static_cast<AudioEngine*>(arg)->_freewheeling = onoff;
+}
+
+void 
+AudioEngine::meter (Port *port, jack_nframes_t nframes)
+{
+	double peak;
+	uint32_t overlen;
+	jack_default_audio_sample_t *buf;
+	
+	buf = port->get_buffer (nframes);
+	peak = port->_peak;
+	overlen = port->overlen;
+	
+	{
+		for (jack_nframes_t n = 0; n < nframes; ++n) {
+			
+			/* 1) peak metering */
+			
+			peak = f_max (peak, buf[n]);
+			
+			/* 2) clip/over metering */
+			
+			if (buf[n] >= 1.0) {
+				overlen++;
+			} else if (overlen) {
+				if (overlen > Port::short_over_length) {
+					port->_short_overs++;
+				}
+				if (overlen > Port::long_over_length) {
+					port->_long_overs++;
+				}
+				overlen = 0;
+			}
+		}
+	}
+	
+        /* post-loop check on the final status of overlen */
+	
+	if (overlen > Port::short_over_length) {
+		port->_short_overs++;
+	}
+	if (overlen > Port::long_over_length) {
+		port->_short_overs++;
+	}
+
+	if (peak > 0.0) {
+		port->_peak_db= 20 * fast_log10 (peak);
+	} else {
+		port->_peak_db = minus_infinity();
+	}
+	
+	port->_peak = peak;
+	port->overlen = overlen;
+}
+
+int
+AudioEngine::process_callback (jack_nframes_t nframes)
+{
+	TentativeLockMonitor tm (_process_lock, __LINE__, __FILE__);
+	jack_nframes_t next_processed_frames;
+
+	/* handle wrap around of total frames counter */
+
+	if (max_frames - _processed_frames < nframes) {
+		next_processed_frames = nframes - (max_frames - _processed_frames);
+	} else {
+		next_processed_frames = _processed_frames + nframes;
+	}
+	
+	if (!tm.locked() || session == 0) {
+		_processed_frames = next_processed_frames;
+		return 0;
+	}
+
+	if (session_remove_pending) {
+		session = 0;
+		session_remove_pending = false;
+		pthread_cond_signal (&session_removed);
+		_processed_frames = next_processed_frames;
+		return 0;
+	}
+
+	if (_freewheeling) {
+		if (Freewheel (nframes)) {
+			_freewheeling = false;
+			jack_set_freewheel (_jack, false);
+		}
+		return 0;
+	}
+
+	/* do input peak metering */
+
+	for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+		if ((*i)->metering) {
+			meter ((*i), nframes);
+		}
+	}
+	
+	session->process (nframes);
+
+	if (!_running) {
+		/* we were zombified, maybe because a ladspa plugin took
+		   too long, or jackd exited, or something like that.
+		*/
+		
+		_processed_frames = next_processed_frames;
+		return 0;
+	}
+		
+	if (last_monitor_check + monitor_check_interval < next_processed_frames) {
+		for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+			
+			Port *port = (*i);
+			bool x;
+			
+			if (port->last_monitor != (x = port->monitoring_input ())) {
+				port->last_monitor = x;
+				/* XXX I think this is dangerous, due to 
+				   a likely mutex in the signal handlers ...
+				*/
+				 port->MonitorInputChanged (x); /* EMIT SIGNAL */
+			}
+		}
+		last_monitor_check = next_processed_frames;
+	}
+
+	_processed_frames = next_processed_frames;
+	return 0;
+}
+
+int
+AudioEngine::_sample_rate_callback (jack_nframes_t nframes, void *arg)
+{
+	return static_cast<AudioEngine *> (arg)->jack_sample_rate_callback (nframes);
+}
+
+int
+AudioEngine::jack_sample_rate_callback (jack_nframes_t nframes)
+{
+	_frame_rate = nframes;
+	_usecs_per_cycle = (int) floor ((((double) frames_per_cycle() / nframes)) * 1000000.0);
+	
+	/* check for monitor input change every 1/10th of second */
+
+	monitor_check_interval = nframes / 10;
+	last_monitor_check = 0;
+
+	if (session) {
+		session->set_frame_rate (nframes);
+	}
+
+	SampleRateChanged (nframes); /* EMIT SIGNAL */
+
+	return 0;
+}
+
+int
+AudioEngine::_bufsize_callback (jack_nframes_t nframes, void *arg)
+{
+	return static_cast<AudioEngine *> (arg)->jack_bufsize_callback (nframes);
+}
+
+int
+AudioEngine::jack_bufsize_callback (jack_nframes_t nframes)
+{
+	_buffer_size = nframes;
+	_usecs_per_cycle = (int) floor ((((double) nframes / frame_rate())) * 1000000.0);
+	last_monitor_check = 0;
+
+	for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+		(*i)->reset();
+	}
+
+	if (session) {
+		session->set_block_size (_buffer_size);
+	}
+
+	return 0;
+}
+
+void 
+AudioEngine::set_session (Session *s)
+{
+	if (!session) {
+		s->set_block_size (jack_get_buffer_size (_jack));
+		s->set_frame_rate (jack_get_sample_rate (_jack));
+		session = s;
+	}
+}
+
+void 
+AudioEngine::remove_session ()
+{
+	LockMonitor lm (_process_lock, __LINE__, __FILE__);
+
+	if (_running) {
+
+		if (session) {
+			session_remove_pending = true;
+			pthread_cond_wait (&session_removed, _process_lock.mutex());
+		} 
+
+	} else {
+
+		session = 0;
+
+	}
+	
+	remove_all_ports ();
+
+}
+
+Port *
+AudioEngine::register_audio_input_port (const string& portname)
+{
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("register audio input port called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return 0;
+		}
+	}
+
+	jack_port_t *p = jack_port_register (_jack, portname.c_str(), JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
+
+	if (p) {
+
+		Port *newport;
+		if ((newport = new Port (p)) != 0) {
+			ports.insert (ports.begin(), newport);
+		}
+		return newport;
+
+	} else {
+
+		pthread_mutex_unlock (_process_lock.mutex());
+		throw PortRegistrationFailure();
+	}
+
+	return 0;
+}
+
+Port *
+AudioEngine::register_audio_output_port (const string& portname)
+{
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("register audio output port called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return 0;
+		}
+	}
+
+	jack_port_t *p;
+
+	if ((p = jack_port_register (_jack, portname.c_str(), JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0)) != 0) {
+		Port *newport = new Port (p);
+		ports.insert (ports.begin(), newport);
+		return newport;
+
+	} else {
+
+		pthread_mutex_unlock (_process_lock.mutex());
+		throw PortRegistrationFailure ();
+	}
+
+	return 0;
+}
+
+int          
+AudioEngine::unregister_port (Port *port)
+{
+	if (!_running) { 
+		/* probably happening when the engine has been halted by JACK,
+		   in which case, there is nothing we can do here.
+		*/
+		return 0;
+	}
+
+	if (port) {
+
+		int ret = jack_port_unregister (_jack, port->port);
+		
+		if (ret == 0) {
+
+			for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+				if ((*i) == port) {
+					ports.erase (i);
+					break;
+				}
+			}
+
+			remove_connections_for (port);
+		}
+
+		return ret;
+
+	} else {
+		return -1;
+	}
+}
+
+int 
+AudioEngine::connect (const string& source, const string& destination)
+{
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("connect called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return -1;
+		}
+	}
+	
+	string s = make_port_name_non_relative (source);
+	string d = make_port_name_non_relative (destination);
+
+	int ret = jack_connect (_jack, s.c_str(), d.c_str());
+
+	if (ret == 0) {
+		pair<string,string> c (s, d);
+		port_connections.push_back (c);
+	} else {
+		error << compose(_("AudioEngine: cannot connect %1 (%2) to %3 (%4)"), 
+				 source, s, destination, d) 
+		      << endmsg;
+	}
+
+	return ret;
+}
+
+int 
+AudioEngine::disconnect (const string& source, const string& destination)
+{
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("disconnect called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return -1;
+		}
+	}
+	
+	string s = make_port_name_non_relative (source);
+	string d = make_port_name_non_relative (destination);
+
+	int ret = jack_disconnect (_jack, s.c_str(), d.c_str());
+
+	if (ret == 0) {
+		pair<string,string> c (s, d);
+		PortConnections::iterator i;
+		
+		if ((i = find (port_connections.begin(), port_connections.end(), c)) != port_connections.end()) {
+			port_connections.erase (i);
+		}
+	}
+	 
+	return ret;
+}
+
+int
+AudioEngine::disconnect (Port *port)
+{
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("disconnect called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return -1;
+		}
+	}
+
+	int ret = jack_port_disconnect (_jack, port->port);
+
+	if (ret == 0) {
+		remove_connections_for (port);
+	}
+
+	return ret;
+
+}
+
+jack_nframes_t
+AudioEngine::frame_rate ()
+{
+	if (_jack) {
+		if (_frame_rate == 0) {
+			return (_frame_rate = jack_get_sample_rate (_jack));
+		} else {
+			return _frame_rate;
+		}
+	} else {
+		fatal << X_("programming error: AudioEngine::frame_rate() called while disconnected from JACK")
+		      << endmsg;
+		/*NOTREACHED*/
+		return 0;
+	}
+}
+
+jack_nframes_t
+AudioEngine::frames_per_cycle ()
+{
+	if (_jack) {
+		if (_buffer_size == 0) {
+			return (_buffer_size = jack_get_buffer_size (_jack));
+		} else {
+			return _buffer_size;
+		}
+	} else {
+		fatal << X_("programming error: AudioEngine::frame_rate() called while disconnected from JACK")
+		      << endmsg;
+		/*NOTREACHED*/
+		return 0;
+	}
+}
+
+Port *
+AudioEngine::get_port_by_name (const string& portname, bool keep)
+{
+	LockMonitor lm (_process_lock, __LINE__, __FILE__);
+
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("get_port_by_name() called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return 0;
+		}
+	}
+	
+	/* check to see if we have a Port for this name already */
+
+	for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+		if (portname == (*i)->name()) {
+			return (*i);
+		}
+	}
+
+	jack_port_t *p;
+
+	if ((p = jack_port_by_name (_jack, portname.c_str())) != 0) {
+		Port *newport = new Port (p);
+		if (keep && newport->is_mine (_jack)) {
+			ports.insert (newport);
+		}
+		return newport;
+	} else {
+		return 0;
+	}
+}
+
+const char **
+AudioEngine::get_ports (const string& port_name_pattern, const string& type_name_pattern, uint32_t flags)
+{
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("get_ports called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return 0;
+		}
+	}
+	return jack_get_ports (_jack, port_name_pattern.c_str(), type_name_pattern.c_str(), flags);
+}
+
+void
+AudioEngine::halted (void *arg)
+{
+	AudioEngine *ae = reinterpret_cast<AudioEngine *> (arg);
+
+	ae->_running = false;
+	ae->_jack = 0;
+
+	ae->_buffer_size = 0;
+	ae->_frame_rate = 0;
+
+	ae->Halted(); /* EMIT SIGNAL */
+}
+
+uint32_t
+AudioEngine::n_physical_outputs () const
+{
+	const char ** ports;
+	uint32_t i = 0;
+
+	if (!_jack) {
+		return 0;
+	}
+
+	if ((ports = jack_get_ports (_jack, NULL, NULL, JackPortIsPhysical|JackPortIsInput)) == 0) {
+		return 0;
+	}
+
+	if (ports) {
+		for (i = 0; ports[i]; ++i);
+		free (ports);
+	}
+	return i;
+}
+
+uint32_t
+AudioEngine::n_physical_inputs () const
+{
+	const char ** ports;
+	uint32_t i = 0;
+	
+	if (!_jack) {
+		return 0;
+	}
+	
+	if ((ports = jack_get_ports (_jack, NULL, NULL, JackPortIsPhysical|JackPortIsOutput)) == 0) {
+		return 0;
+	}
+
+	if (ports) {
+		for (i = 0; ports[i]; ++i);
+		free (ports);
+	}
+	return i;
+}
+
+string
+
+AudioEngine::get_nth_physical (uint32_t n, int flag)
+{
+	const char ** ports;
+	uint32_t i;
+	string ret;
+
+	if (!_running || !_jack) {
+		if (!_has_run) {
+			fatal << _("get_nth_physical called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} else {
+			return "";
+		}
+	}
+
+	ports = jack_get_ports (_jack, NULL, NULL, JackPortIsPhysical|flag);
+	
+	if (ports == 0) {
+		return "";
+	}
+
+	for (i = 0; i < n && ports[i]; ++i);
+
+	if (ports[i]) {
+		ret = ports[i];
+	}
+
+	free ((char *) ports);
+
+	return ret;
+}
+
+jack_nframes_t
+AudioEngine::get_port_total_latency (const Port& port)
+{
+	if (!_jack) {
+		fatal << _("get_port_total_latency() called with no JACK client connection") << endmsg;
+		/*NOTREACHED*/
+	}
+
+	if (!_running) {
+		if (!_has_run) {
+			fatal << _("get_port_total_latency() called before engine was started") << endmsg;
+			/*NOTREACHED*/
+		} 
+	}
+
+	return jack_port_get_total_latency (_jack, port.port);
+}
+
+void
+AudioEngine::transport_stop ()
+{
+	// cerr << "tell JACK to stop\n";
+	if (_jack) {
+		jack_transport_stop (_jack);
+	}
+}
+
+void
+AudioEngine::transport_start ()
+{
+	// cerr << "tell JACK to start\n";
+	if (_jack) {
+		jack_transport_start (_jack);
+	}
+}
+
+void
+AudioEngine::transport_locate (jack_nframes_t where)
+{
+	// cerr << "tell JACK to locate to " << where << endl;
+	if (_jack) {
+		jack_transport_locate (_jack, where);
+	}
+}
+
+AudioEngine::TransportState
+AudioEngine::transport_state ()
+{
+	if (_jack) {
+		jack_position_t pos;
+		return (TransportState) jack_transport_query (_jack, &pos);
+	} else {
+		return (TransportState) JackTransportStopped;
+	}
+}
+
+int
+AudioEngine::reset_timebase ()
+{
+	if (_jack) {
+		if (Config->get_jack_time_master()) {
+			return jack_set_timebase_callback (_jack, 0, _jack_timebase_callback, this);
+		} else {
+			return jack_release_timebase (_jack);
+		}
+	} else {
+		return -1;
+	}
+}
+
+int
+AudioEngine::freewheel (bool onoff)
+{
+	if (_jack) {
+
+		if (onoff) {
+			_freewheel_thread_registered = false;
+		}
+
+		return jack_set_freewheel (_jack, onoff);
+
+	} else {
+		return -1;
+	}
+}
+
+void
+AudioEngine::remove_all_ports ()
+{
+	/* process lock MUST be held */
+
+	if (_jack) {
+		for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+			jack_port_unregister (_jack, (*i)->port);
+		}
+	}
+
+	ports.clear ();
+	port_connections.clear ();
+}
+
+void
+AudioEngine::remove_connections_for (Port* port)
+{
+	for (PortConnections::iterator i = port_connections.begin(); i != port_connections.end(); ) {
+		PortConnections::iterator tmp;
+		
+		tmp = i;
+		++tmp;
+		
+		if ((*i).first == port->name()) {
+			port_connections.erase (i);
+		}
+
+		i = tmp;
+	}
+}
+
+#ifdef HAVE_JACK_CLIENT_OPEN
+
+int
+AudioEngine::connect_to_jack (string client_name)
+{
+	jack_options_t options = JackNullOption;
+	jack_status_t status;
+	const char *server_name = NULL;
+
+	jack_client_name = client_name; /* might be reset below */
+
+	_jack = jack_client_open (jack_client_name.c_str(), options, &status, server_name);
+	
+	if (_jack == NULL) {
+
+		if (status & JackServerFailed) {
+			error << _("Unable to connect to JACK server") << endmsg;
+		}
+		
+		error << compose (_("Could not connect to JACK server as  \"%1\""), jack_client_name) <<  endmsg;
+		return -1;
+	}
+
+	if (status & JackServerStarted) {
+		info << _("JACK server started") << endmsg;
+	}
+
+	if (status & JackNameNotUnique) {
+		jack_client_name = jack_get_client_name (_jack);
+	}
+	
+	return 0;
+}
+
+#else
+
+int
+AudioEngine::connect_to_jack (string client_name)
+{
+	jack_client_name = client_name;
+
+	if ((_jack = jack_client_new (client_name.c_str())) == NULL) {
+		return -1;
+	}
+
+	return 0;
+}
+
+#endif /* HAVE_JACK_CLIENT_OPEN */
+
+int 
+AudioEngine::disconnect_from_jack ()
+{
+	if (_jack == 0) {
+		return 0;
+	}
+
+	if (jack_client_close (_jack)) {
+		error << _("cannot shutdown connection to JACK") << endmsg;
+	}
+
+	_buffer_size = 0;
+	_frame_rate = 0;
+
+	if (_running) {
+		_running = false;
+		Stopped(); /* EMIT SIGNAL */
+	}
+
+	_jack = 0;
+	return 0;
+}
+
+int
+AudioEngine::reconnect_to_jack ()
+{
+	if (_jack) {
+		disconnect_from_jack ();
+		/* XXX give jackd a chance */
+		usleep (250000);
+	}
+
+	if (connect_to_jack (jack_client_name)) {
+		error << _("failed to connect to JACK") << endmsg;
+		return -1;
+	}
+
+	Ports::iterator i;
+
+	for (i = ports.begin(); i != ports.end(); ++i) {
+
+		/* XXX hack hack hack */
+
+		string long_name = (*i)->name();
+		string short_name;
+		
+		short_name = long_name.substr (long_name.find_last_of (':') + 1);
+
+		if (((*i)->port = jack_port_register (_jack, short_name.c_str(), (*i)->type(), (*i)->flags(), 0)) == 0) {
+			error << compose (_("could not reregister %1"), (*i)->name()) << endmsg;
+			break;
+		} else {
+		}
+
+		(*i)->reset ();
+
+		if ((*i)->flags() & JackPortIsOutput) {
+			(*i)->silence (jack_get_buffer_size (_jack), 0);
+		}
+	}
+
+	if (i != ports.end()) {
+		for (Ports::iterator i = ports.begin(); i != ports.end(); ++i) {
+			jack_port_unregister (_jack, (*i)->port);
+		}
+		return -1;
+	} 
+
+
+	if (session) {
+		jack_nframes_t blocksize = jack_get_buffer_size (_jack);
+		session->set_block_size (blocksize);
+		session->set_frame_rate (jack_get_sample_rate (_jack));
+	}
+
+	last_monitor_check = 0;
+	
+	jack_on_shutdown (_jack, halted, this);
+	jack_set_graph_order_callback (_jack, _graph_order_callback, this);
+	jack_set_thread_init_callback (_jack, _thread_init_callback, this);
+	jack_set_process_callback (_jack, _process_callback, this);
+	jack_set_sample_rate_callback (_jack, _sample_rate_callback, this);
+	jack_set_buffer_size_callback (_jack, _bufsize_callback, this);
+	jack_set_xrun_callback (_jack, _xrun_callback, this);
+	jack_set_sync_callback (_jack, _jack_sync_callback, this);
+	jack_set_freewheel_callback (_jack, _freewheel_callback, this);
+	
+	if (Config->get_jack_time_master()) {
+		jack_set_timebase_callback (_jack, 0, _jack_timebase_callback, this);
+	}
+	
+	if (jack_activate (_jack) == 0) {
+		_running = true;
+		_has_run = true;
+	} else {
+		return -1;
+	}
+
+	/* re-establish connections */
+	
+	for (PortConnections::iterator i = port_connections.begin(); i != port_connections.end(); ++i) {
+		
+		int err;
+		
+		if ((err = jack_connect (_jack, (*i).first.c_str(), (*i).second.c_str())) != 0) {
+			if (err != EEXIST) {
+				error << compose (_("could not reconnect %1 and %2 (err = %3)"),
+						  (*i).first, (*i).second, err)
+				      << endmsg;
+			}
+		}
+	}
+
+	Running (); /* EMIT SIGNAL*/
+
+	return 0;
+}
+
+int
+AudioEngine::request_buffer_size (jack_nframes_t nframes)
+{
+	if (_jack) {
+		int ret = jack_set_buffer_size (_jack, nframes);
+		return ret;
+	} else {
+		return -1;
+	}
+}
+
+void
+AudioEngine::update_total_latencies ()
+{
+#ifdef HAVE_JACK_RECOMPUTE_LATENCIES
+	jack_recompute_total_latencies (_jack);
+#endif
+}
+		
+string
+AudioEngine::make_port_name_relative (string portname)
+{
+	string::size_type len;
+	string::size_type n;
+	
+	len = portname.length();
+
+	for (n = 0; n < len; ++n) {
+		if (portname[n] == ':') {
+			break;
+		}
+	}
+	
+	if ((n != len) && (portname.substr (0, n) == jack_client_name)) {
+		return portname.substr (n+1);
+	}
+
+	return portname;
+}
+
+string
+AudioEngine::make_port_name_non_relative (string portname)
+{
+	string str;
+
+	if (portname.find_first_of (':') != string::npos) {
+		return portname;
+	}
+
+	str  = jack_client_name;
+	str += ':';
+	str += portname;
+	
+	return str;
+}
+