start work on the changes to EngineControl (dialog) to integrate with new backend design, and add "requires-driver" concept to AudioBackend to handle JACK specifically

4 files changed, 171 insertions, 843 deletions

diff --git a/gtk2_ardour/ardev_common.sh.in b/gtk2_ardour/ardev_common.sh.in
index 897bfcf7c2..2bd9c51515 100644
--- a/gtk2_ardour/ardev_common.sh.in
+++ b/gtk2_ardour/ardev_common.sh.in
@@ -17,6 +17,7 @@ export ARDOUR_DATA_PATH=$TOP:$TOP/build:$TOP/gtk2_ardour:$TOP/build/gtk2_ardour:
 export ARDOUR_MIDIMAPS_PATH=$TOP/midi_maps:.
 export ARDOUR_MCP_PATH=$TOP/mcp:.
 export ARDOUR_EXPORT_FORMATS_PATH=$TOP/export:.
+export ARDOUR_BACKEND_PATH=$TOP/build/libs/ardour
 
 #
 # even though we set the above variables, ardour requires that these 
diff --git a/gtk2_ardour/ardour_ui.cc b/gtk2_ardour/ardour_ui.cc
index 7e6ce10300..fca86c585b 100644
--- a/gtk2_ardour/ardour_ui.cc
+++ b/gtk2_ardour/ardour_ui.cc
@@ -397,7 +397,6 @@ ARDOUR_UI::attach_to_engine ()
 	engine->SampleRateChanged.connect (forever_connections, MISSING_INVALIDATOR, boost::bind (&ARDOUR_UI::update_sample_rate, this, _1), gui_context());
 
 	engine->Halted.connect_same_thread (forever_connections, boost::bind (&ARDOUR_UI::engine_halted, this, _1, false));
-	engine->BackendAvailable.connect_same_thread (forever_connections, boost::bind (&ARDOUR_UI::post_engine, this));
 
 	ARDOUR::Port::set_connecting_blocked (ARDOUR_COMMAND_LINE::no_connect_ports);
 
diff --git a/gtk2_ardour/engine_dialog.cc b/gtk2_ardour/engine_dialog.cc
index b52d3a7a15..b4e5c72050 100644
--- a/gtk2_ardour/engine_dialog.cc
+++ b/gtk2_ardour/engine_dialog.cc
@@ -66,33 +66,25 @@ using namespace PBD;
 using namespace Glib;
 
 EngineControl::EngineControl ()
-	: periods_adjustment (2, 2, 16, 1, 2),
-	  periods_spinner (periods_adjustment),
-	  ports_adjustment (128, 8, 1024, 1, 16),
-	  ports_spinner (ports_adjustment),
-	  input_latency_adjustment (0, 0, 99999, 1),
-	  input_latency (input_latency_adjustment),
-	  output_latency_adjustment (0, 0, 99999, 1),
-	  output_latency (output_latency_adjustment),
-	  realtime_button (_("Realtime")),
-	  no_memory_lock_button (_("Do not lock memory")),
-	  unlock_memory_button (_("Unlock memory")),
-	  soft_mode_button (_("No zombies")),
-	  monitor_button (_("Provide monitor ports")),
-	  force16bit_button (_("Force 16 bit")),
-	  hw_monitor_button (_("H/W monitoring")),
-	  hw_meter_button (_("H/W metering")),
-	  verbose_output_button (_("Verbose output")),
-	  start_button (_("Start")),
-	  stop_button (_("Stop")),
+	: input_latency_adjustment (0, 0, 99999, 1)
+	, input_latency (input_latency_adjustment)
+	, output_latency_adjustment (0, 0, 99999, 1)
+	, output_latency (output_latency_adjustment)
+	, input_channels_adjustment (2, 0, 256, 1)
+	, input_channels (input_channels_adjustment)
+	, output_channels_adjustment (2, 0, 256, 1)
+	, output_channels (output_channels_adjustment)
+	, ports_adjustment (128, 8, 1024, 1, 16)
+	, ports_spinner (ports_adjustment)
+	, realtime_button (_("Realtime"))
 #ifdef __APPLE___
-	  basic_packer (5, 2),
-	  options_packer (4, 2),
-	  device_packer (4, 2)
+	, basic_packer (6, 2)
+	, options_packer (4, 2)
+	, device_packer (4, 2)
 #else
-	  basic_packer (8, 2),
-	  options_packer (14, 2),
-	  device_packer (6, 2)
+	, basic_packer (9, 2)
+	, options_packer (14, 2)
+	, device_packer (6, 2)
 #endif
 {
 	using namespace Notebook_Helpers;
@@ -102,59 +94,24 @@ EngineControl::EngineControl ()
 
 	_used = false;
 
-	strings.push_back (_("8000Hz"));
-	strings.push_back (_("22050Hz"));
-	strings.push_back (_("44100Hz"));
-	strings.push_back (_("48000Hz"));
-	strings.push_back (_("88200Hz"));
-	strings.push_back (_("96000Hz"));
-	strings.push_back (_("192000Hz"));
-	set_popdown_strings (sample_rate_combo, strings);
-	sample_rate_combo.set_active_text ("48000Hz");
+	/* basic parameters */
 
-	strings.clear ();
-	strings.push_back ("32");
-	strings.push_back ("64");
-	strings.push_back ("128");
-	strings.push_back ("256");
-	strings.push_back ("512");
-	strings.push_back ("1024");
-	strings.push_back ("2048");
-	strings.push_back ("4096");
-	strings.push_back ("8192");
-	set_popdown_strings (period_size_combo, strings);
-	period_size_combo.set_active_text ("1024");
+	basic_packer.set_spacings (6);
 
 	strings.clear ();
-	strings.push_back (_("None"));
-	strings.push_back (_("Triangular"));
-	strings.push_back (_("Rectangular"));
-	strings.push_back (_("Shaped"));
-	set_popdown_strings (dither_mode_combo, strings);
-	dither_mode_combo.set_active_text (_("None"));
 
-	/* basic parameters */
+	vector<const ARDOUR::AudioBackendInfo*> backends = ARDOUR::AudioEngine::instance()->available_backends();
+	for (vector<const ARDOUR::AudioBackendInfo*>::const_iterator b = backends.begin(); b != backends.end(); ++b) {
+		strings.push_back ((*b)->name);
+	}
 
-	basic_packer.set_spacings (6);
+	set_popdown_strings (backend_combo, strings);
+	backend_combo.set_active_text (strings.front());
 
-	strings.clear ();
-#ifdef __APPLE__
-	strings.push_back (X_("CoreAudio"));
-#else
-#ifndef __FreeBSD__
-	strings.push_back (X_("ALSA"));
-#endif
-	strings.push_back (X_("OSS"));
-	strings.push_back (X_("FreeBoB"));
-	strings.push_back (X_("FFADO"));
-#endif
-	strings.push_back (X_("NetJACK"));
-	strings.push_back (X_("Dummy"));
-	set_popdown_strings (driver_combo, strings);
-	driver_combo.set_active_text (strings.front());
+	backend_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::backend_changed));
+	backend_changed ();
 
 	driver_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::driver_changed));
-	driver_changed ();
 
 	strings.clear ();
 	strings.push_back (_("Playback/recording on 1 device"));
@@ -176,6 +133,11 @@ EngineControl::EngineControl ()
 
 	row = 0;
 
+	label = manage (left_aligned_label (_("Audio Driver:")));
+	basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
+	basic_packer.attach (backend_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
+	row++;
+
 	label = manage (left_aligned_label (_("Driver:")));
 	basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
 	basic_packer.attach (driver_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
@@ -193,16 +155,8 @@ EngineControl::EngineControl ()
 
 	label = manage (left_aligned_label (_("Buffer size:")));
 	basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	basic_packer.attach (period_size_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	row++;
-
-#if !defined(__APPLE__) && !defined(__FreeBSD__)
-	label = manage (left_aligned_label (_("Number of buffers:")));
-	basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	basic_packer.attach (periods_spinner, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	periods_spinner.set_value (2);
+	basic_packer.attach (buffer_size_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
 	row++;
-#endif
 
 	label = manage (left_aligned_label (_("Approximate latency:")));
 	basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
@@ -210,8 +164,7 @@ EngineControl::EngineControl ()
 	row++;
 
 	sample_rate_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::redisplay_latency));
-	periods_adjustment.signal_value_changed().connect (sigc::mem_fun (*this, &EngineControl::redisplay_latency));
-	period_size_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::redisplay_latency));
+	buffer_size_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::redisplay_latency));
 	redisplay_latency();
 	row++;
 	/* no audio mode with CoreAudio, its duplex or nuthin' */
@@ -227,22 +180,7 @@ EngineControl::EngineControl ()
 	input_device_combo.set_size_request (250, -1);
 	output_device_combo.set_size_request (250, -1);
 
-	/*
-
-	if (engine_running()) {
-		start_button.set_sensitive (false);
-	} else {
-		stop_button.set_sensitive (false);
-	}
-
-	start_button.signal_clicked().connect (sigc::mem_fun (*this, &EngineControl::start_engine));
-	stop_button.signal_clicked().connect (sigc::mem_fun (*this, &EngineControl::start_engine));
-	*/
-
-	button_box.pack_start (start_button, false, false);
-	button_box.pack_start (stop_button, false, false);
-
-	// basic_packer.attach (button_box, 0, 2, 8, 9, FILL|EXPAND, (AttachOptions) 0);
+	interface_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::interface_changed));
 
 	/* options */
 
@@ -254,46 +192,6 @@ EngineControl::EngineControl ()
 
 	realtime_button.set_active (true);
 
-#if PROVIDE_TOO_MANY_OPTIONS
-
-#if !defined(__APPLE__) && !defined(__FreeBSD__)
-	options_packer.attach (no_memory_lock_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (unlock_memory_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (soft_mode_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (monitor_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (force16bit_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (hw_monitor_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (hw_meter_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-	options_packer.attach (verbose_output_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-#else
-	options_packer.attach (verbose_output_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-#endif
-
-	strings.clear ();
-	strings.push_back (_("Ignore"));
-	strings.push_back ("500 msec");
-	strings.push_back ("1 sec");
-	strings.push_back ("2 sec");
-	strings.push_back ("10 sec");
-	set_popdown_strings (timeout_combo, strings);
-	timeout_combo.set_active_text (strings.front ());
-
-	label = manage (new Label (_("Client timeout")));
-	label->set_alignment (1.0, 0.5);
-	options_packer.attach (timeout_combo, 1, 2, row, row + 1, FILL|EXPAND, AttachOptions(0));
-	options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-	++row;
-
-#endif /* PROVIDE_TOO_MANY_OPTIONS */
 	label = manage (left_aligned_label (_("Number of ports:")));
 	options_packer.attach (ports_spinner, 1, 2, row, row + 1, FILL|EXPAND, AttachOptions(0));
 	options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
@@ -311,23 +209,6 @@ EngineControl::EngineControl ()
 	++row;
 #endif
 
-	find_jack_servers (server_strings);
-
-	if (server_strings.empty()) {
-		fatal << _("No JACK server found anywhere on this system. Please install JACK and restart") << endmsg;
-		/*NOTREACHED*/
-	}
-
-	set_popdown_strings (serverpath_combo, server_strings);
-	serverpath_combo.set_active_text (server_strings.front());
-
-	if (server_strings.size() > 1) {
-		label = manage (left_aligned_label (_("Server:")));
-		options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-		options_packer.attach (serverpath_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-		++row;
-	}
-
 	/* device settings */
 
 	device_packer.set_spacings (6);
@@ -386,514 +267,93 @@ EngineControl::~EngineControl ()
 }
 
 void
-EngineControl::build_command_line (vector<string>& cmd)
+EngineControl::backend_changed ()
 {
-	string str;
-	string driver;
-	bool using_alsa = false;
-	bool using_coreaudio = false;
-	bool using_dummy = false;
-	bool using_ffado = false;
-
-	/* first, path to jackd */
-
-	cmd.push_back (serverpath_combo.get_active_text ());
-
-	/* now jackd arguments */
-
-	str = timeout_combo.get_active_text ();
+	string backend_name = backend_combo.get_active_text();
+	boost::shared_ptr<ARDOUR::AudioBackend> backend;
 
-	if (str != _("Ignore")) {
-
-		double secs = 0;
-		uint32_t msecs;
-		secs = atof (str);
-		msecs = (uint32_t) floor (secs * 1000.0);
-
-		if (msecs > 0) {
-			cmd.push_back ("-t");
-			cmd.push_back (to_string (msecs, std::dec));
-		}
-	}
-
-	if (no_memory_lock_button.get_active()) {
-		cmd.push_back ("-m"); /* no munlock */
+	if (!(backend = ARDOUR::AudioEngine::instance()->set_backend (backend_name, "ardour", ""))) {
+		/* eh? */
+		return;
 	}
 
-	cmd.push_back ("-p"); /* port max */
-	cmd.push_back (to_string ((uint32_t) floor (ports_spinner.get_value()), std::dec));
-
-	if (realtime_button.get_active()) {
-		cmd.push_back ("-R");
+	if (backend->requires_driver_selection()) {
+		vector<string> drivers = backend->enumerate_drivers();
+		set_popdown_strings (driver_combo, drivers);
+		driver_combo.set_active_text (drivers.front());
+		driver_changed ();
 	} else {
-		cmd.push_back ("-r"); /* override jackd's default --realtime */
-	}
-
-	if (unlock_memory_button.get_active()) {
-		cmd.push_back ("-u");
-	}
-
-	if (verbose_output_button.get_active()) {
-		cmd.push_back ("-v");
+		list_devices ();
 	}
-
-	/* now add fixed arguments (not user-selectable) */
-
-	cmd.push_back ("-T"); // temporary */
-
-	/* next the driver */
-
-	cmd.push_back ("-d");
-
-	driver = driver_combo.get_active_text ();
-
-	if (driver == X_("ALSA")) {
-		using_alsa = true;
-		cmd.push_back ("alsa");
-	} else if (driver == X_("OSS")) {
-		cmd.push_back ("oss");
-	} else if (driver == X_("CoreAudio")) {
-		using_coreaudio = true;
-		cmd.push_back ("coreaudio");
-	} else if (driver == X_("NetJACK")) {
-		cmd.push_back ("netjack");
-	} else if (driver == X_("FreeBoB")) {
-		cmd.push_back ("freebob");
-	} else if (driver == X_("FFADO")) {
-		using_ffado = true;
-		cmd.push_back ("firewire");
-	} else if ( driver == X_("Dummy")) {
-		using_dummy = true;
-		cmd.push_back ("dummy");
-	}
-
-	/* driver arguments */
-
-	if (!using_coreaudio) {
-		str = audio_mode_combo.get_active_text();
-
-		if (str == _("Playback/recording on 1 device")) {
-
-			/* relax */
-
-		} else if (str == _("Playback/recording on 2 devices")) {
-
-			string input_device = get_device_name (driver, input_device_combo.get_active_text());
-			string output_device = get_device_name (driver, output_device_combo.get_active_text());
-
-			if (input_device.empty() || output_device.empty()) {
-				cmd.clear ();
-				return;
-			}
-
-			cmd.push_back ("-C");
-			cmd.push_back (input_device);
-
-			cmd.push_back ("-P");
-			cmd.push_back (output_device);
-
-		} else if (str == _("Playback only")) {
-			cmd.push_back ("-P");
-		} else if (str == _("Recording only")) {
-			cmd.push_back ("-C");
-		}
-
-		if (!using_dummy) {
-			cmd.push_back ("-n");
-			cmd.push_back (to_string ((uint32_t) floor (periods_spinner.get_value()), std::dec));
-		}
-	}
-
-	cmd.push_back ("-r");
-	cmd.push_back (to_string (get_rate(), std::dec));
-
-	cmd.push_back ("-p");
-	cmd.push_back (period_size_combo.get_active_text());
-
-	if (using_alsa || using_ffado || using_coreaudio) {
-
-		double val = input_latency_adjustment.get_value();
-
-                if (val) {
-                        cmd.push_back ("-I");
-                        cmd.push_back (to_string ((uint32_t) val, std::dec));
-                }
-
-                val = output_latency_adjustment.get_value();
-
-		if (val) {
-                        cmd.push_back ("-O");
-                        cmd.push_back (to_string ((uint32_t) val, std::dec));
-                }
-	}
-
-	if (using_alsa) {
-
-		if (audio_mode_combo.get_active_text() != _("Playback/recording on 2 devices")) {
-
-			string device = get_device_name (driver, interface_combo.get_active_text());
-			if (device.empty()) {
-				cmd.clear ();
-				return;
-			}
-
-			cmd.push_back ("-d");
-			cmd.push_back (device);
-		}
-
-		if (hw_meter_button.get_active()) {
-			cmd.push_back ("-M");
-		}
-
-		if (hw_monitor_button.get_active()) {
-			cmd.push_back ("-H");
-		}
-
-		str = dither_mode_combo.get_active_text();
-
-		if (str == _("None")) {
-		} else if (str == _("Triangular")) {
-			cmd.push_back ("-z triangular");
-		} else if (str == _("Rectangular")) {
-			cmd.push_back ("-z rectangular");
-		} else if (str == _("Shaped")) {
-			cmd.push_back ("-z shaped");
-		}
-
-		if (force16bit_button.get_active()) {
-			cmd.push_back ("-S");
-		}
-
-		if (soft_mode_button.get_active()) {
-			cmd.push_back ("-s");
-		}
-
-		str = midi_driver_combo.get_active_text ();
-
-		if (str == _("seq")) {
-			cmd.push_back ("-X seq");
-		} else if (str == _("raw")) {
-			cmd.push_back ("-X raw");
-		}
-	} else if (using_coreaudio) {
-
-#ifdef __APPLE__
-		// note: older versions of the CoreAudio JACK backend use -n instead of -d here
-
-		string device = get_device_name (driver, interface_combo.get_active_text());
-		if (device.empty()) {
-			cmd.clear ();
-			return;
-		}
-
-		cmd.push_back ("-d");
-		cmd.push_back (device);
-#endif
-
-	}
-}
-
-int
-EngineControl::setup_engine ()
-{
-	vector<string> args;
-	std::string cwd = "/tmp";
-
-	build_command_line (args);
-
-	if (args.empty()) {
-		return 1; // try again
-	}
-
-	std::string jackdrc_path = Glib::get_home_dir();
-	jackdrc_path += "/.jackdrc";
-
-	ofstream jackdrc (jackdrc_path.c_str());
-	if (!jackdrc) {
-		error << string_compose (_("cannot open JACK rc file %1 to store parameters"), jackdrc_path) << endmsg;
-		return -1;
-	}
-
-	for (vector<string>::iterator i = args.begin(); i != args.end(); ++i) {
-		jackdrc << (*i) << ' ';
-	}
-
-	jackdrc << endl;
-	jackdrc.close ();
-
-	_used = true;
-
-	return 0;
 }
 
 void
-EngineControl::enumerate_devices (const string& driver)
-{
-	/* note: case matters for the map keys */
-
-	if (driver == "CoreAudio") {
-#ifdef __APPLE__
-		devices[driver] = enumerate_coreaudio_devices ();
-#endif
-
-#if !defined(__APPLE__) && !defined(__FreeBSD__)
-	} else if (driver == "ALSA") {
-		devices[driver] = enumerate_alsa_devices ();
-	} else if (driver == "FreeBOB") {
-		devices[driver] = enumerate_freebob_devices ();
-	} else if (driver == "FFADO") {
-		devices[driver] = enumerate_ffado_devices ();
-	} else if (driver == "OSS") {
-		devices[driver] = enumerate_oss_devices ();
-	} else if (driver == "Dummy") {
-		devices[driver] = enumerate_dummy_devices ();
-	} else if (driver == "NetJACK") {
-		devices[driver] = enumerate_netjack_devices ();
-	}
-#else
-        }
-#endif
-}
-
-#ifdef __APPLE__
-static OSStatus
-getDeviceUIDFromID( AudioDeviceID id, char *name, size_t nsize)
-{
-	UInt32 size = sizeof(CFStringRef);
-	CFStringRef UI;
-	OSStatus res = AudioDeviceGetProperty(id, 0, false,
-		kAudioDevicePropertyDeviceUID, &size, &UI);
-	if (res == noErr)
-		CFStringGetCString(UI,name,nsize,CFStringGetSystemEncoding());
-	CFRelease(UI);
-	return res;
-}
-
-vector<string>
-EngineControl::enumerate_coreaudio_devices ()
-{
-	vector<string> devs;
-
-	// Find out how many Core Audio devices are there, if any...
-	// (code snippet gently "borrowed" from St?hane Letz jackdmp;)
-	OSStatus err;
-	Boolean isWritable;
-	UInt32 outSize = sizeof(isWritable);
-
-	backend_devs.clear ();
-
-	err = AudioHardwareGetPropertyInfo(kAudioHardwarePropertyDevices,
-					   &outSize, &isWritable);
-	if (err == noErr) {
-		// Calculate the number of device available...
-		int numCoreDevices = outSize / sizeof(AudioDeviceID);
-		// Make space for the devices we are about to get...
-		AudioDeviceID *coreDeviceIDs = new AudioDeviceID [numCoreDevices];
-		err = AudioHardwareGetProperty(kAudioHardwarePropertyDevices,
-					       &outSize, (void *) coreDeviceIDs);
-		if (err == noErr) {
-			// Look for the CoreAudio device name...
-			char coreDeviceName[256];
-			UInt32 nameSize;
-
-			for (int i = 0; i < numCoreDevices; i++) {
-
-				nameSize = sizeof (coreDeviceName);
-
-				/* enforce duplex devices only */
-
-				err = AudioDeviceGetPropertyInfo(coreDeviceIDs[i],
-								 0, true, kAudioDevicePropertyStreams,
-								 &outSize, &isWritable);
-
-				if (err != noErr || outSize == 0) {
-					continue;
-				}
-
-				err = AudioDeviceGetPropertyInfo(coreDeviceIDs[i],
-								 0, false, kAudioDevicePropertyStreams,
-								 &outSize, &isWritable);
-
-				if (err != noErr || outSize == 0) {
-					continue;
-				}
-
-				err = AudioDeviceGetPropertyInfo(coreDeviceIDs[i],
-								 0, true, kAudioDevicePropertyDeviceName,
-								 &outSize, &isWritable);
-				if (err == noErr) {
-					err = AudioDeviceGetProperty(coreDeviceIDs[i],
-								     0, true, kAudioDevicePropertyDeviceName,
-								     &nameSize, (void *) coreDeviceName);
-					if (err == noErr) {
-						char drivername[128];
-
-						// this returns the unique id for the device
-						// that must be used on the commandline for jack
-
-						if (getDeviceUIDFromID(coreDeviceIDs[i], drivername, sizeof (drivername)) == noErr) {
-							devs.push_back (coreDeviceName);
-							backend_devs.push_back (drivername);
-						}
-					}
-				}
-			}
-		}
-		delete [] coreDeviceIDs;
-	}
-
-
-	if (devs.size() == 0) {
-		MessageDialog msg (string_compose (_("\
-You do not have any audio devices capable of\n\
-simultaneous playback and recording.\n\n\
-Please use Applications -> Utilities -> Audio MIDI Setup\n\
-to create an \"aggregrate\" device, or install a suitable\n\
-audio interface.\n\n\
-Please send email to Apple and ask them why new Macs\n\
-have no duplex audio device.\n\n\
-Alternatively, if you really want just playback\n\
-or recording but not both, start JACK before running\n\
-%1 and choose the relevant device then."
-							   ), PROGRAM_NAME),
-				   true, Gtk::MESSAGE_ERROR, Gtk::BUTTONS_OK);
-		msg.set_title (_("No suitable audio devices"));
-		msg.set_position (Gtk::WIN_POS_MOUSE);
-		msg.run ();
-		exit (1);
-	}
-
-
-	return devs;
-}
-#else
-
-#if !defined(__FreeBSD__)
-vector<string>
-EngineControl::enumerate_alsa_devices ()
+EngineControl::list_devices ()
 {
-	vector<string> devs;
-
-	snd_ctl_t *handle;
-	snd_ctl_card_info_t *info;
-	snd_pcm_info_t *pcminfo;
-	snd_ctl_card_info_alloca(&info);
-	snd_pcm_info_alloca(&pcminfo);
-	string devname;
-	int cardnum = -1;
-	int device = -1;
-
-	backend_devs.clear ();
-
-	while (snd_card_next (&cardnum) >= 0 && cardnum >= 0) {
-
-		devname = "hw:";
-		devname += to_string (cardnum, std::dec);
-
-		if (snd_ctl_open (&handle, devname.c_str(), 0) >= 0 && snd_ctl_card_info (handle, info) >= 0) {
-
-			while (snd_ctl_pcm_next_device (handle, &device) >= 0 && device >= 0) {
+	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+	assert (backend);
 
-				snd_pcm_info_set_device (pcminfo, device);
-				snd_pcm_info_set_subdevice (pcminfo, 0);
-				snd_pcm_info_set_stream (pcminfo, SND_PCM_STREAM_PLAYBACK);
-
-				if (snd_ctl_pcm_info (handle, pcminfo) >= 0) {
-					devs.push_back (snd_pcm_info_get_name (pcminfo));
-					devname += ',';
-					devname += to_string (device, std::dec);
-					backend_devs.push_back (devname);
-				}
-			}
-
-			snd_ctl_close(handle);
-		}
-	}
-
-	return devs;
-}
-#endif
-
-vector<string>
-EngineControl::enumerate_ffado_devices ()
-{
-	vector<string> devs;
-	backend_devs.clear ();
-	return devs;
+	/* now fill out devices, mark sample rates, buffer sizes insensitive */
+	    
+	vector<string> devices = backend->enumerate_devices ();
+	
+	set_popdown_strings (interface_combo, devices);
+	interface_combo.set_active_text (devices.front());
+	set_popdown_strings (input_device_combo, devices);
+	input_device_combo.set_active_text (devices.front());
+	set_popdown_strings (output_device_combo, devices);
+	output_device_combo.set_active_text (devices.front());
+	
+	interface_changed ();
 }
-
-vector<string>
-EngineControl::enumerate_freebob_devices ()
+	
+void
+EngineControl::driver_changed ()
 {
-	vector<string> devs;
-	return devs;
-}
+	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+	assert (backend);
 
-vector<string>
-EngineControl::enumerate_oss_devices ()
-{
-	vector<string> devs;
-	return devs;
-}
-vector<string>
-EngineControl::enumerate_dummy_devices ()
-{
-	vector<string> devs;
-	return devs;
-}
-vector<string>
-EngineControl::enumerate_netjack_devices ()
-{
-	vector<string> devs;
-	return devs;
+	backend->set_driver (driver_combo.get_active_text());
+	list_devices ();
 }
-#endif
 
 void
-EngineControl::driver_changed ()
+EngineControl::interface_changed ()
 {
-	string driver = driver_combo.get_active_text();
-	string::size_type maxlen = 0;
-	int n = 0;
-
-	enumerate_devices (driver);
-
-	vector<string>& strings = devices[driver];
-
-	if (strings.empty() && driver != "FreeBoB" && driver != "FFADO" && driver != "Dummy") {
-		return;
-	}
-
-	for (vector<string>::iterator i = strings.begin(); i != strings.end(); ++i, ++n) {
-		if ((*i).length() > maxlen) {
-			maxlen = (*i).length();
+	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+	assert (backend);
+	string device_name = interface_combo.get_active_text ();
+	vector<string> s;
+
+	/* sample rates */
+
+	vector<float> sr = backend->available_sample_rates (device_name);
+	for (vector<float>::const_iterator x = sr.begin(); x != sr.end(); ++x) {
+		char buf[32];
+		if (fmod (*x, 1000.0f)) {
+			snprintf (buf, sizeof (buf), "%.1f kHz", (*x)/1000.0);
+		} else {
+			snprintf (buf, sizeof (buf), "%.0f kHz", (*x)/1000.0);
 		}
+		s.push_back (buf);
 	}
 
-	set_popdown_strings (interface_combo, strings);
-	set_popdown_strings (input_device_combo, strings);
-	set_popdown_strings (output_device_combo, strings);
+	set_popdown_strings (sample_rate_combo, s);
+	sample_rate_combo.set_active_text (s.front());
 
-	if (!strings.empty()) {
-		interface_combo.set_active_text (strings.front());
-		input_device_combo.set_active_text (strings.front());
-		output_device_combo.set_active_text (strings.front());
-	}
+	/* buffer sizes */
 
-	if (driver == "ALSA") {
-		soft_mode_button.set_sensitive (true);
-		force16bit_button.set_sensitive (true);
-		hw_monitor_button.set_sensitive (true);
-		hw_meter_button.set_sensitive (true);
-		monitor_button.set_sensitive (true);
-	} else {
-		soft_mode_button.set_sensitive (false);
-		force16bit_button.set_sensitive (false);
-		hw_monitor_button.set_sensitive (false);
-		hw_meter_button.set_sensitive (false);
-		monitor_button.set_sensitive (false);
+	s.clear ();
+	vector<uint32_t> bs = backend->available_buffer_sizes(device_name);
+	for (vector<uint32_t>::const_iterator x = bs.begin(); x != bs.end(); ++x) {
+		char buf[32];
+		snprintf (buf, sizeof (buf), "%u", *x);
+		s.push_back (buf);
 	}
-}
+
+	set_popdown_strings (buffer_size_combo, s);
+	buffer_size_combo.set_active_text (s.front());
+}	
 
 uint32_t
 EngineControl::get_rate ()
@@ -912,15 +372,10 @@ void
 EngineControl::redisplay_latency ()
 {
 	uint32_t rate = get_rate();
-#if defined(__APPLE__) || defined(__FreeBSD__)
-	float periods = 2;
-#else
-	float periods = periods_adjustment.get_value();
-#endif
-	float period_size = atof (period_size_combo.get_active_text());
+	float period_size = atof (buffer_size_combo.get_active_text());
 
 	char buf[32];
-	snprintf (buf, sizeof(buf), "%.1fmsec", (periods * period_size) / (rate/1000.0));
+	snprintf (buf, sizeof(buf), "%.1fmsec", (2 * period_size) / (rate/1000.0));
 
 	latency_label.set_text (buf);
 	latency_label.set_alignment (0, 0.5);
@@ -946,127 +401,6 @@ EngineControl::audio_mode_changed ()
 	}
 }
 
-static bool jack_server_filter(const string& str, void */*arg*/)
-{
-   return str == "jackd" || str == "jackdmp";
-}
-
-void
-EngineControl::find_jack_servers (vector<string>& strings)
-{
-#ifdef __APPLE__
-	/* this magic lets us finds the path to the OSX bundle, and then
-	   we infer JACK's location from there
-	*/
-
-	char execpath[MAXPATHLEN+1];
-	uint32_t pathsz = sizeof (execpath);
-
-	_NSGetExecutablePath (execpath, &pathsz);
-
-	string path (Glib::path_get_dirname (execpath));
-	path += "/jackd";
-
-	if (Glib::file_test (path, FILE_TEST_EXISTS)) {
-		strings.push_back (path);
-	}
-
-	if (getenv ("ARDOUR_WITH_JACK")) {
-		/* no other options - only use the JACK we supply */
-		if (strings.empty()) {
-			fatal << string_compose (_("JACK appears to be missing from the %1 bundle"), PROGRAM_NAME) << endmsg;
-			/*NOTREACHED*/
-		}
-		return;
-	}
-#else
-	string path;
-#endif
-
-	PathScanner scanner;
-	vector<string *> *jack_servers;
-	std::map<string,int> un;
-	char *p;
-	bool need_minimal_path = false;
-
-	p = getenv ("PATH");
-
-	if (p && *p) {
-		path = p;
-	} else {
-		need_minimal_path = true;
-	}
-
-#ifdef __APPLE__
-	// many mac users don't have PATH set up to include
-	// likely installed locations of JACK
-	need_minimal_path = true;
-#endif
-
-	if (need_minimal_path) {
-		if (path.empty()) {
-			path = "/usr/bin:/bin:/usr/local/bin:/opt/local/bin";
-		} else {
-			path += ":/usr/local/bin:/opt/local/bin";
-		}
-	}
-
-#ifdef __APPLE__
-	// push it back into the environment so that auto-started JACK can find it.
-	// XXX why can't we just expect OS X users to have PATH set correctly? we can't ...
-	setenv ("PATH", path.c_str(), 1);
-#endif
-
-	jack_servers = scanner (path, jack_server_filter, 0, false, true);
-	if (!jack_servers) {
-		return;
-	}
-
-	vector<string *>::iterator iter;
-
-	for (iter = jack_servers->begin(); iter != jack_servers->end(); iter++) {
-		string p = **iter;
-
-		if (un[p]++ == 0) {
-			strings.push_back(p);
-		}
-	}
-}
-
-
-string
-EngineControl::get_device_name (const string& driver, const string& human_readable)
-{
-	vector<string>::iterator n;
-	vector<string>::iterator i;
-
-	if (human_readable.empty()) {
-		/* this can happen if the user's .ardourrc file has a device name from
-		   another computer system in it
-		*/
-		MessageDialog msg (_("You need to choose an audio device first."));
-                msg.set_position (WIN_POS_MOUSE);
-		msg.run ();
-		return string();
-	}
-
-	if (backend_devs.empty()) {
-		return human_readable;
-	}
-
-	for (i = devices[driver].begin(), n = backend_devs.begin(); i != devices[driver].end(); ++i, ++n) {
-		if (human_readable == (*i)) {
-			return (*n);
-		}
-	}
-
-	if (i == devices[driver].end()) {
-		warning << string_compose (_("Audio device \"%1\" not known on this computer."), human_readable) << endmsg;
-	}
-
-	return string();
-}
-
 XMLNode&
 EngineControl::get_state ()
 {
@@ -1074,6 +408,7 @@ EngineControl::get_state ()
 	XMLNode* child;
 	std::string path;
 
+#if 0
 	child = new XMLNode ("periods");
 	child->add_property ("val", to_string (periods_adjustment.get_value(), std::dec));
 	root->add_child_nocopy (*child);
@@ -1165,7 +500,7 @@ EngineControl::get_state ()
 	child = new XMLNode ("mididriver");
 	child->add_property ("val", midi_driver_combo.get_active_text());
 	root->add_child_nocopy (*child);
-
+#endif
 	return *root;
 }
 
@@ -1181,7 +516,7 @@ EngineControl::set_state (const XMLNode& root)
 
 	int val;
 	string strval;
-
+#if 0
 	if ( (child = root.child ("driver"))){
 		prop = child->property("val");
 
@@ -1316,4 +651,10 @@ EngineControl::set_state (const XMLNode& root)
 			midi_driver_combo.set_active_text(strval);
 		}
 	}
+#endif
+}
+
+int
+EngineControl::setup_engine ()
+{
 }
diff --git a/gtk2_ardour/engine_dialog.h b/gtk2_ardour/engine_dialog.h
index 0d7ce29b46..ac96fbc520 100644
--- a/gtk2_ardour/engine_dialog.h
+++ b/gtk2_ardour/engine_dialog.h
@@ -47,80 +47,67 @@ class EngineControl : public Gtk::VBox {
 	void set_state (const XMLNode&);
 
   private:
-	Gtk::Adjustment periods_adjustment;
-	Gtk::SpinButton periods_spinner;
-	Gtk::Adjustment ports_adjustment;
-	Gtk::SpinButton ports_spinner;
-	Gtk::Adjustment input_latency_adjustment;
-	Gtk::SpinButton input_latency;
-	Gtk::Adjustment output_latency_adjustment;
-	Gtk::SpinButton output_latency;
-	Gtk::Label latency_label;
-
-	Gtk::CheckButton realtime_button;
-	Gtk::CheckButton no_memory_lock_button;
-	Gtk::CheckButton unlock_memory_button;
-	Gtk::CheckButton soft_mode_button;
-	Gtk::CheckButton monitor_button;
-	Gtk::CheckButton force16bit_button;
-	Gtk::CheckButton hw_monitor_button;
-	Gtk::CheckButton hw_meter_button;
-	Gtk::CheckButton verbose_output_button;
-
-	Gtk::Button start_button;
-	Gtk::Button stop_button;
-	Gtk::HButtonBox button_box;
-
-	Gtk::ComboBoxText sample_rate_combo;
-	Gtk::ComboBoxText period_size_combo;
-
-	Gtk::ComboBoxText preset_combo;
-	Gtk::ComboBoxText serverpath_combo;
-	Gtk::ComboBoxText driver_combo;
-	Gtk::ComboBoxText interface_combo;
-	Gtk::ComboBoxText timeout_combo;
-	Gtk::ComboBoxText dither_mode_combo;
-	Gtk::ComboBoxText audio_mode_combo;
-	Gtk::ComboBoxText input_device_combo;
-	Gtk::ComboBoxText output_device_combo;
-	Gtk::ComboBoxText midi_driver_combo;
-
-	Gtk::Table basic_packer;
-	Gtk::Table options_packer;
-	Gtk::Table device_packer;
-	Gtk::HBox basic_hbox;
-	Gtk::HBox options_hbox;
-	Gtk::HBox device_hbox;
-	Gtk::Notebook notebook;
-
-	bool _used;
-
-        static bool engine_running ();
-
-	void driver_changed ();
-	void build_command_line (std::vector<std::string>&);
-
-	std::map<std::string,std::vector<std::string> > devices;
-	std::vector<std::string> backend_devs;
-	void enumerate_devices (const std::string& driver);
-
-#ifdef __APPLE__
-	std::vector<std::string> enumerate_coreaudio_devices ();
-#else
-	std::vector<std::string> enumerate_alsa_devices ();
-	std::vector<std::string> enumerate_oss_devices ();
-	std::vector<std::string> enumerate_netjack_devices ();
-	std::vector<std::string> enumerate_freebob_devices ();
-	std::vector<std::string> enumerate_ffado_devices ();
-	std::vector<std::string> enumerate_dummy_devices ();
-#endif
-
-	void redisplay_latency ();
-	uint32_t get_rate();
-	void audio_mode_changed ();
-	std::vector<std::string> server_strings;
-	void find_jack_servers (std::vector<std::string>&);
-	std::string get_device_name (const std::string& driver, const std::string& human_readable_name);
+    /* core fields used by all backends */
+
+    Gtk::ComboBoxText backend_combo;
+    Gtk::ComboBoxText input_device_combo;
+    Gtk::ComboBoxText output_device_combo;
+    Gtk::ComboBoxText sample_rate_combo;
+    Gtk::ComboBoxText buffer_size_combo;
+    Gtk::Adjustment input_latency_adjustment;
+    Gtk::SpinButton input_latency;
+    Gtk::Adjustment output_latency_adjustment;
+    Gtk::SpinButton output_latency;
+    Gtk::Adjustment input_channels_adjustment;
+    Gtk::SpinButton input_channels;
+    Gtk::Adjustment output_channels_adjustment;
+    Gtk::SpinButton output_channels;
+    Gtk::Adjustment ports_adjustment;
+    Gtk::SpinButton ports_spinner;
+    Gtk::Label latency_label;
+
+    /* JACK specific */
+    
+    Gtk::CheckButton realtime_button;
+    Gtk::CheckButton no_memory_lock_button;
+    Gtk::CheckButton unlock_memory_button;
+    Gtk::CheckButton soft_mode_button;
+    Gtk::CheckButton monitor_button;
+    Gtk::CheckButton force16bit_button;
+    Gtk::CheckButton hw_monitor_button;
+    Gtk::CheckButton hw_meter_button;
+    Gtk::CheckButton verbose_output_button;
+    
+    
+    Gtk::ComboBoxText preset_combo;
+    Gtk::ComboBoxText serverpath_combo;
+    Gtk::ComboBoxText driver_combo;
+    Gtk::ComboBoxText interface_combo;
+    Gtk::ComboBoxText timeout_combo;
+    Gtk::ComboBoxText dither_mode_combo;
+    Gtk::ComboBoxText audio_mode_combo;
+    Gtk::ComboBoxText midi_driver_combo;
+    
+    Gtk::Table basic_packer;
+    Gtk::Table options_packer;
+    Gtk::Table device_packer;
+    Gtk::HBox basic_hbox;
+    Gtk::HBox options_hbox;
+    Gtk::HBox device_hbox;
+    Gtk::Notebook notebook;
+    
+    bool _used;
+    
+    static bool engine_running ();
+    
+    void driver_changed ();
+    void backend_changed ();
+
+    void redisplay_latency ();
+    uint32_t get_rate();
+    void audio_mode_changed ();
+    void interface_changed ();
+    void list_devices ();
 };
 
 #endif /* __gtk2_ardour_engine_dialog_h__ */