call me Mr. Backend

simple blocking (no callback) PortAudio Backend

gtk2_ardour/ardev_common.sh.in

@@ -17,7 +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=$TOP/export:.
-export ARDOUR_BACKEND_PATH=$libs/backends/jack:$libs/backends/wavesaudio:$libs/backends/dummy:$libs/backends/alsa:$libs/backends/coreaudio
+export ARDOUR_BACKEND_PATH=$libs/backends/jack:$libs/backends/wavesaudio:$libs/backends/dummy:$libs/backends/alsa:$libs/backends/coreaudio:$libs/backends/portaudio
 export ARDOUR_TEST_PATH=$TOP/libs/ardour/test/data
 export PBD_TEST_PATH=$TOP/libs/pbd/test
 export EVORAL_TEST_PATH=$TOP/libs/evoral/test/testdata

libs/backends/portaudio/portaudio_backend.h

@@ -0,0 +1,413 @@
+/*
+ * Copyright (C) 2014-2015 Robin Gareus <robin@gareus.org>
+ * Copyright (C) 2013 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 __libbackend_portaudio_backend_h__
+#define __libbackend_portaudio_backend_h__
+
+#include <string>
+#include <vector>
+#include <set>
+
+#include <stdint.h>
+#include <pthread.h>
+
+#include <boost/shared_ptr.hpp>
+
+#include "ardour/audio_backend.h"
+#include "ardour/types.h"
+
+#include "portaudio_io.h"
+
+namespace ARDOUR {
+
+class PortAudioBackend;
+
+class PortMidiEvent {
+	public:
+		PortMidiEvent (const pframes_t timestamp, const uint8_t* data, size_t size);
+		PortMidiEvent (const PortMidiEvent& other);
+		~PortMidiEvent ();
+		size_t size () const { return _size; };
+		pframes_t timestamp () const { return _timestamp; };
+		const unsigned char* const_data () const { return _data; };
+		unsigned char* data () { return _data; };
+		bool operator< (const PortMidiEvent &other) const { return timestamp () < other.timestamp (); };
+	private:
+		size_t _size;
+		pframes_t _timestamp;
+		uint8_t *_data;
+};
+
+typedef std::vector<boost::shared_ptr<PortMidiEvent> > PortMidiBuffer;
+
+class PamPort { // PortAudio / PortMidi Backend Port
+	protected:
+		PamPort (PortAudioBackend &b, const std::string&, PortFlags);
+	public:
+		virtual ~PamPort ();
+
+		const std::string& name () const { return _name; }
+		PortFlags flags () const { return _flags; }
+
+		int set_name (const std::string &name) { _name = name; return 0; }
+
+		virtual DataType type () const = 0;
+
+		bool is_input ()     const { return flags () & IsInput; }
+		bool is_output ()    const { return flags () & IsOutput; }
+		bool is_physical ()  const { return flags () & IsPhysical; }
+		bool is_terminal ()  const { return flags () & IsTerminal; }
+		bool is_connected () const { return _connections.size () != 0; }
+		bool is_connected (const PamPort *port) const;
+		bool is_physically_connected () const;
+
+		const std::vector<PamPort *>& get_connections () const { return _connections; }
+
+		int connect (PamPort *port);
+		int disconnect (PamPort *port);
+		void disconnect_all ();
+
+		virtual void* get_buffer (pframes_t nframes) = 0;
+
+		const LatencyRange latency_range (bool for_playback) const
+		{
+			return for_playback ? _playback_latency_range : _capture_latency_range;
+		}
+
+		void set_latency_range (const LatencyRange &latency_range, bool for_playback)
+		{
+			if (for_playback)
+			{
+				_playback_latency_range = latency_range;
+			}
+			else
+			{
+				_capture_latency_range = latency_range;
+			}
+		}
+
+	private:
+		PortAudioBackend &_osx_backend;
+		std::string _name;
+		const PortFlags _flags;
+		LatencyRange _capture_latency_range;
+		LatencyRange _playback_latency_range;
+		std::vector<PamPort*> _connections;
+
+		void _connect (PamPort* , bool);
+		void _disconnect (PamPort* , bool);
+
+}; // class PamPort
+
+class PortAudioPort : public PamPort {
+	public:
+		PortAudioPort (PortAudioBackend &b, const std::string&, PortFlags);
+		~PortAudioPort ();
+
+		DataType type () const { return DataType::AUDIO; };
+
+		Sample* buffer () { return _buffer; }
+		const Sample* const_buffer () const { return _buffer; }
+		void* get_buffer (pframes_t nframes);
+
+	private:
+		Sample _buffer[8192];
+}; // class PortAudioPort
+
+class PortMidiPort : public PamPort {
+	public:
+		PortMidiPort (PortAudioBackend &b, const std::string&, PortFlags);
+		~PortMidiPort ();
+
+		DataType type () const { return DataType::MIDI; };
+
+		void* get_buffer (pframes_t nframes);
+		const PortMidiBuffer * const_buffer () const { return & _buffer[_bufperiod]; }
+
+		void next_period() { if (_n_periods > 1) { get_buffer(0); _bufperiod = (_bufperiod + 1) % _n_periods; } }
+		void set_n_periods(int n) { if (n > 0 && n < 3) { _n_periods = n; } }
+
+	private:
+		PortMidiBuffer _buffer[2];
+		int _n_periods;
+		int _bufperiod;
+}; // class PortMidiPort
+
+class PortAudioBackend : public AudioBackend {
+	friend class PamPort;
+	public:
+		PortAudioBackend (AudioEngine& e, AudioBackendInfo& info);
+		~PortAudioBackend ();
+
+		/* AUDIOBACKEND API */
+
+		std::string name () const;
+		bool is_realtime () const;
+
+		std::vector<DeviceStatus> enumerate_devices () const;
+		std::vector<float> available_sample_rates (const std::string& device) const;
+		std::vector<uint32_t> available_buffer_sizes (const std::string& device) const;
+		uint32_t available_input_channel_count (const std::string& device) const;
+		uint32_t available_output_channel_count (const std::string& device) const;
+
+		bool can_change_sample_rate_when_running () const;
+		bool can_change_buffer_size_when_running () const;
+
+		int set_device_name (const std::string&);
+		int set_sample_rate (float);
+		int set_buffer_size (uint32_t);
+		int set_interleaved (bool yn);
+		int set_input_channels (uint32_t);
+		int set_output_channels (uint32_t);
+		int set_systemic_input_latency (uint32_t);
+		int set_systemic_output_latency (uint32_t);
+		int set_systemic_midi_input_latency (std::string const, uint32_t) { return 0; }
+		int set_systemic_midi_output_latency (std::string const, uint32_t) { return 0; }
+
+		int reset_device () { return 0; };
+
+		/* Retrieving parameters */
+		std::string  device_name () const;
+		float        sample_rate () const;
+		uint32_t     buffer_size () const;
+		bool         interleaved () const;
+		uint32_t     input_channels () const;
+		uint32_t     output_channels () const;
+		uint32_t     systemic_input_latency () const;
+		uint32_t     systemic_output_latency () const;
+		uint32_t     systemic_midi_input_latency (std::string const) const { return 0; }
+		uint32_t     systemic_midi_output_latency (std::string const) const { return 0; }
+
+		bool can_set_systemic_midi_latencies () const { return false; }
+
+		/* External control app */
+		std::string control_app_name () const { return std::string (); }
+		void launch_control_app () {}
+
+		/* MIDI */
+		std::vector<std::string> enumerate_midi_options () const;
+		int set_midi_option (const std::string&);
+		std::string midi_option () const;
+
+		std::vector<DeviceStatus> enumerate_midi_devices () const {
+			return std::vector<AudioBackend::DeviceStatus> ();
+		}
+		int set_midi_device_enabled (std::string const, bool) {
+			return 0;
+		}
+		bool midi_device_enabled (std::string const) const {
+			return true;
+		}
+
+	protected:
+		/* State Control */
+		int _start (bool for_latency_measurement);
+	public:
+		int stop ();
+		int freewheel (bool);
+		float dsp_load () const;
+		size_t raw_buffer_size (DataType t);
+
+		/* Process time */
+		framepos_t sample_time ();
+		framepos_t sample_time_at_cycle_start ();
+		pframes_t samples_since_cycle_start ();
+
+		int create_process_thread (boost::function<void()> func);
+		int join_process_threads ();
+		bool in_process_thread ();
+		uint32_t process_thread_count ();
+
+		void update_latencies ();
+
+		/* PORTENGINE API */
+
+		void* private_handle () const;
+		const std::string& my_name () const;
+		bool available () const;
+		uint32_t port_name_size () const;
+
+		int         set_port_name (PortHandle, const std::string&);
+		std::string get_port_name (PortHandle) const;
+		PortHandle  get_port_by_name (const std::string&) const;
+
+		int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>&) const;
+
+		DataType port_data_type (PortHandle) const;
+
+		PortHandle register_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
+		void unregister_port (PortHandle);
+
+		int  connect (const std::string& src, const std::string& dst);
+		int  disconnect (const std::string& src, const std::string& dst);
+		int  connect (PortHandle, const std::string&);
+		int  disconnect (PortHandle, const std::string&);
+		int  disconnect_all (PortHandle);
+
+		bool connected (PortHandle, bool process_callback_safe);
+		bool connected_to (PortHandle, const std::string&, bool process_callback_safe);
+		bool physically_connected (PortHandle, bool process_callback_safe);
+		int  get_connections (PortHandle, std::vector<std::string>&, bool process_callback_safe);
+
+		/* MIDI */
+		int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t** buf, void* port_buffer, uint32_t event_index);
+		int midi_event_put (void* port_buffer, pframes_t timestamp, const uint8_t* buffer, size_t size);
+		uint32_t get_midi_event_count (void* port_buffer);
+		void     midi_clear (void* port_buffer);
+
+		/* Monitoring */
+
+		bool can_monitor_input () const;
+		int  request_input_monitoring (PortHandle, bool);
+		int  ensure_input_monitoring (PortHandle, bool);
+		bool monitoring_input (PortHandle);
+
+		/* Latency management */
+
+		void         set_latency_range (PortHandle, bool for_playback, LatencyRange);
+		LatencyRange get_latency_range (PortHandle, bool for_playback);
+
+		/* Discovering physical ports */
+
+		bool      port_is_physical (PortHandle) const;
+		void      get_physical_outputs (DataType type, std::vector<std::string>&);
+		void      get_physical_inputs (DataType type, std::vector<std::string>&);
+		ChanCount n_physical_outputs () const;
+		ChanCount n_physical_inputs () const;
+
+		/* Getting access to the data buffer for a port */
+
+		void* get_buffer (PortHandle, pframes_t);
+
+		void* main_process_thread ();
+
+	private:
+		std::string _instance_name;
+		PortAudioIO *_pcmio;
+
+		bool  _run; /* keep going or stop, ardour thread */
+		bool  _active; /* is running, process thread */
+		bool  _freewheel;
+		bool  _freewheeling;
+		bool  _measure_latency;
+
+		uint64_t _last_process_start;
+
+		static std::vector<std::string> _midi_options;
+		static std::vector<AudioBackend::DeviceStatus> _audio_device_status;
+		static std::vector<AudioBackend::DeviceStatus> _midi_device_status;
+
+		mutable std::string _audio_device;
+		std::string _midi_driver_option;
+
+		/* audio settings */
+		float  _samplerate;
+		size_t _samples_per_period;
+		static size_t _max_buffer_size;
+
+		uint32_t _n_inputs;
+		uint32_t _n_outputs;
+
+		uint32_t _systemic_audio_input_latency;
+		uint32_t _systemic_audio_output_latency;
+
+		/* portaudio specific  */
+		int name_to_id(std::string) const;
+
+		/* processing */
+		float  _dsp_load;
+		framecnt_t _processed_samples;
+		pthread_t _main_thread;
+
+		/* process threads */
+		static void* portaudio_process_thread (void *);
+		std::vector<pthread_t> _threads;
+
+		struct ThreadData {
+			PortAudioBackend* engine;
+			boost::function<void ()> f;
+			size_t stacksize;
+
+			ThreadData (PortAudioBackend* e, boost::function<void ()> fp, size_t stacksz)
+				: engine (e) , f (fp) , stacksize (stacksz) {}
+		};
+
+		/* port engine */
+		PortHandle add_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
+		int register_system_audio_ports ();
+		void unregister_ports (bool system_only = false);
+
+		std::vector<PamPort *> _ports;
+		std::vector<PamPort *> _system_inputs;
+		std::vector<PamPort *> _system_outputs;
+		std::vector<PamPort *> _system_midi_in;
+		std::vector<PamPort *> _system_midi_out;
+
+		struct PortConnectData {
+			std::string a;
+			std::string b;
+			bool c;
+
+			PortConnectData (const std::string& a, const std::string& b, bool c)
+				: a (a) , b (b) , c (c) {}
+		};
+
+		std::vector<PortConnectData *> _port_connection_queue;
+		pthread_mutex_t _port_callback_mutex;
+		bool _port_change_flag;
+
+		void port_connect_callback (const std::string& a, const std::string& b, bool conn) {
+			pthread_mutex_lock (&_port_callback_mutex);
+			_port_connection_queue.push_back(new PortConnectData(a, b, conn));
+			pthread_mutex_unlock (&_port_callback_mutex);
+		}
+
+		void port_connect_add_remove_callback () {
+			pthread_mutex_lock (&_port_callback_mutex);
+			_port_change_flag = true;
+			pthread_mutex_unlock (&_port_callback_mutex);
+		}
+
+		bool valid_port (PortHandle port) const {
+			return std::find (_ports.begin (), _ports.end (), (PamPort*)port) != _ports.end ();
+		}
+
+		PamPort * find_port (const std::string& port_name) const {
+			for (std::vector<PamPort*>::const_iterator it = _ports.begin (); it != _ports.end (); ++it) {
+				if ((*it)->name () == port_name) {
+					return *it;
+				}
+			}
+			return NULL;
+		}
+
+		PamPort * find_port_in (std::vector<PamPort *> plist, const std::string& port_name) const {
+			for (std::vector<PamPort*>::const_iterator it = plist.begin (); it != plist.end (); ++it) {
+				if ((*it)->name () == port_name) {
+					return *it;
+				}
+			}
+			return NULL;
+		}
+
+}; // class PortAudioBackend
+
+} // namespace
+
+#endif /* __libbackend_portaudio_backend_h__ */

libs/backends/portaudio/portaudio_io.cc

@@ -0,0 +1,452 @@
+/*
+ * Copyright (C) 2015 Robin Gareus <robin@gareus.org>
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "portaudio_io.h"
+
+using namespace ARDOUR;
+
+PortAudioIO::PortAudioIO ()
+	: _state (-1)
+	, _initialized (false)
+	, _capture_channels (0)
+	, _playback_channels (0)
+	, _stream (0)
+	, _input_buffer (0)
+	, _output_buffer (0)
+	, _cur_sample_rate (0)
+	, _cur_input_latency (0)
+	, _cur_output_latency (0)
+{
+}
+
+PortAudioIO::~PortAudioIO ()
+{
+	if (_state == 0) {
+		pcm_stop();
+	}
+	if (_initialized) {
+		Pa_Terminate();
+	}
+
+	for (std::map<int, paDevice*>::const_iterator i = _devices.begin (); i != _devices.end(); ++i) {
+		delete i->second;
+	}
+	_devices.clear();
+
+	free (_input_buffer); _input_buffer = NULL;
+	free (_output_buffer); _output_buffer = NULL;
+}
+
+
+int
+PortAudioIO::available_sample_rates(int device_id, std::vector<float>& sampleRates)
+{
+	static const float ardourRates[] = { 8000.0, 22050.0, 24000.0, 44100.0, 48000.0, 88200.0, 96000.0, 176400.0, 192000.0};
+
+	assert(_initialized);
+
+	// TODO use  separate int device_input, int device_output ?!
+	if (device_id == -1) {
+		device_id = Pa_GetDefaultInputDevice();
+	}
+#ifndef NDEBUG
+	printf("PortAudio: Querying Samplerates for device %d\n", device_id);
+#endif
+
+	sampleRates.clear();
+	const PaDeviceInfo* nfo = Pa_GetDeviceInfo(device_id);
+
+        PaStreamParameters inputParam;
+        PaStreamParameters outputParam;
+
+        inputParam.device = device_id;
+        inputParam.channelCount = nfo->maxInputChannels;
+        inputParam.sampleFormat = paFloat32;
+        inputParam.suggestedLatency = 0;
+        inputParam.hostApiSpecificStreamInfo = 0;
+
+        outputParam.device = device_id;
+        outputParam.channelCount = nfo->maxOutputChannels;
+        outputParam.sampleFormat = paFloat32;
+        outputParam.suggestedLatency = 0;
+        outputParam.hostApiSpecificStreamInfo = 0;
+
+	for (uint32_t i = 0; i < sizeof(ardourRates)/sizeof(float); ++i) {
+		if (paFormatIsSupported == Pa_IsFormatSupported(
+					nfo->maxInputChannels > 0 ? &inputParam : NULL,
+					nfo->maxOutputChannels > 0 ? &outputParam : NULL,
+					ardourRates[i])) {
+			sampleRates.push_back (ardourRates[i]);
+		}
+	}
+
+	if (sampleRates.empty()) {
+		sampleRates.push_back (48000.0);
+	}
+
+	return 0;
+}
+
+int
+PortAudioIO::available_buffer_sizes(int device_id, std::vector<uint32_t>& bufferSizes)
+{
+	// TODO
+	static const uint32_t ardourSizes[] = { 64, 128, 256, 512, 1024, 2048, 4096 };
+	for(uint32_t i = 0; i < sizeof(ardourSizes)/sizeof(uint32_t); ++i) {
+		bufferSizes.push_back (ardourSizes[i]);
+	}
+	return 0;
+}
+
+void
+PortAudioIO::device_list (std::map<int, std::string> &devices) const {
+	devices.clear();
+	for (std::map<int, paDevice*>::const_iterator i = _devices.begin (); i != _devices.end(); ++i) {
+		devices.insert (std::pair<int, std::string> (i->first, i->second->name));
+	}
+}
+
+void
+PortAudioIO::discover()
+{
+	for (std::map<int, paDevice*>::const_iterator i = _devices.begin (); i != _devices.end(); ++i) {
+		delete i->second;
+	}
+	_devices.clear();
+	
+	PaError err = paNoError;
+
+	if (!_initialized) {
+		err = Pa_Initialize();
+	}
+	if (err != paNoError) {
+		return;
+	}
+
+	_initialized = true;
+
+	{
+		const PaDeviceInfo* nfo_i = Pa_GetDeviceInfo(Pa_GetDefaultInputDevice());
+		const PaDeviceInfo* nfo_o = Pa_GetDeviceInfo(Pa_GetDefaultOutputDevice());
+		if (nfo_i && nfo_o) {
+			_devices.insert (std::pair<int, paDevice*> (-1,
+						new paDevice("Default",
+							nfo_i->maxInputChannels,
+							nfo_o->maxOutputChannels
+							)));
+		}
+	}
+
+	int n_devices = Pa_GetDeviceCount();
+#ifndef NDEBUG
+	printf("PortAudio %d devices found:\n", n_devices);
+#endif
+
+	for (int i = 0 ; i < n_devices; ++i) {
+		const PaDeviceInfo* nfo = Pa_GetDeviceInfo(i);
+		if (!nfo) continue;
+#ifndef NDEBUG
+		printf(" (%d) '%s' in: %d (lat: %.1f .. %.1f) out: %d (lat: %.1f .. %.1f) sr:%.2f\n",
+				i, nfo->name,
+				nfo->maxInputChannels,
+				nfo->defaultLowInputLatency * 1e3,
+				nfo->defaultHighInputLatency * 1e3,
+				nfo->maxOutputChannels,
+				nfo->defaultLowOutputLatency * 1e3,
+				nfo->defaultHighOutputLatency * 1e3,
+				nfo->defaultSampleRate);
+#endif
+		if ( nfo->maxInputChannels == 0 && nfo->maxOutputChannels == 0) {
+			continue;
+		}
+		_devices.insert (std::pair<int, paDevice*> (i, new paDevice(
+						nfo->name,
+						nfo->maxInputChannels,
+						nfo->maxOutputChannels
+						)));
+	}
+}
+
+void
+PortAudioIO::pcm_stop ()
+{
+	if (_stream) {
+		Pa_CloseStream (_stream);
+	}
+	_stream = NULL;
+
+	_capture_channels = 0;
+	_playback_channels = 0;
+	_cur_sample_rate = 0;
+	_cur_input_latency = 0;
+	_cur_output_latency = 0;
+
+	free (_input_buffer); _input_buffer = NULL;
+	free (_output_buffer); _output_buffer = NULL;
+	_state = -1;
+}
+
+int
+PortAudioIO::pcm_start()
+{
+	PaError err = Pa_StartStream (_stream);
+
+	if (err != paNoError) {
+		_state = -1;
+		return -1;
+	}
+	return 0;
+}
+
+#ifdef __APPLE__
+static uint32_t lower_power_of_two (uint32_t v) {
+	v--;
+	v |= v >> 1;
+	v |= v >> 2;
+	v |= v >> 4;
+	v |= v >> 8;
+	v |= v >> 16;
+	v++;
+	return v >> 1;
+}
+#endif
+
+int
+PortAudioIO::pcm_setup (
+		int device_input, int device_output,
+		double sample_rate, uint32_t samples_per_period)
+{
+	_state = -2;
+
+	// TODO error reporting sans fprintf()
+
+	PaError err = paNoError;
+	const PaDeviceInfo *nfo_in;
+	const PaDeviceInfo *nfo_out;
+	const PaStreamInfo *nfo_s;
+		
+	if (!_initialized) {
+		err = Pa_Initialize();
+	}
+	if (err != paNoError) {
+		fprintf(stderr, "PortAudio Initialization Failed\n");
+		goto error;
+	}
+	_initialized = true;
+
+
+	if (device_input == -1) {
+		device_input = Pa_GetDefaultInputDevice();
+	}
+	if (device_output == -1) {
+		device_output = Pa_GetDefaultOutputDevice();
+	}
+
+	_capture_channels = 0;
+	_playback_channels = 0;
+	_cur_sample_rate = 0;
+	_cur_input_latency = 0;
+	_cur_output_latency = 0;
+
+#ifndef NDEBUG
+	printf("PortAudio Device IDs: i:%d o:%d\n", device_input, device_output);
+#endif
+
+	nfo_in = Pa_GetDeviceInfo(device_input);
+	nfo_out = Pa_GetDeviceInfo(device_output);
+
+	if (!nfo_in && ! nfo_out) {
+		fprintf(stderr, "PortAudio Cannot Query Device Info\n");
+		goto error;
+	}
+
+	if (nfo_in) {
+		_capture_channels = nfo_in->maxInputChannels;
+	}
+	if (nfo_out) {
+		_playback_channels = nfo_out->maxOutputChannels;
+	}
+
+	if(_capture_channels == 0 && _playback_channels == 0) {
+		fprintf(stderr, "PortAudio no Input and no output channels.\n");
+		goto error;
+	}
+
+
+#ifdef __APPLE__
+	// pa_mac_core_blocking.c pa_stable_v19_20140130
+	// BUG: ringbuffer alloc requires power-of-two chn count.
+	if ((_capture_channels & (_capture_channels - 1)) != 0) {
+		printf("Adjusted capture channes to power of two (portaudio rb bug)\n");
+		_capture_channels = lower_power_of_two (_capture_channels);
+	}
+
+	if ((_playback_channels & (_playback_channels - 1)) != 0) {
+		printf("Adjusted capture channes to power of two (portaudio rb bug)\n");
+		_playback_channels = lower_power_of_two (_playback_channels);
+	}
+#endif
+	
+#ifndef NDEBUG
+	printf("PortAudio Channels: in:%d out:%d\n",
+			_capture_channels, _playback_channels);
+#endif
+
+	PaStreamParameters inputParam;
+	PaStreamParameters outputParam;
+
+	if (nfo_in) {
+		inputParam.device = device_input;
+		inputParam.channelCount = _capture_channels;
+		inputParam.sampleFormat = paFloat32;
+		inputParam.suggestedLatency = nfo_in->defaultLowInputLatency;
+		inputParam.hostApiSpecificStreamInfo = NULL;
+	}
+
+	if (nfo_out) {
+		outputParam.device = device_output;
+		outputParam.channelCount = _playback_channels;
+		outputParam.sampleFormat = paFloat32;
+		outputParam.suggestedLatency = nfo_out->defaultLowOutputLatency;
+		outputParam.hostApiSpecificStreamInfo = NULL;
+	}
+
+	// XXX re-consider using callback API, testing needed.
+	err = Pa_OpenStream (
+			&_stream,
+			_capture_channels > 0 ? &inputParam: NULL,
+			_playback_channels > 0 ? &outputParam: NULL,
+			sample_rate,
+			samples_per_period,
+			paClipOff | paDitherOff,
+			NULL, NULL);
+
+	if (err != paNoError) {
+		fprintf(stderr, "PortAudio failed to start stream.\n");
+		goto error;
+	}
+
+	nfo_s = Pa_GetStreamInfo (_stream);
+	if (!nfo_s) {
+		fprintf(stderr, "PortAudio failed to query stream information.\n");
+		pcm_stop();
+		goto error;
+	}
+
+	_cur_sample_rate = nfo_s->sampleRate;
+	_cur_input_latency = nfo_s->inputLatency * _cur_sample_rate;
+	_cur_output_latency = nfo_s->outputLatency * _cur_sample_rate;
+
+#ifndef NDEBUG
+	printf("PA Sample Rate  %.1f SPS\n", _cur_sample_rate);
+	printf("PA Input Latency  %.1fms  %d spl\n", 1e3 * nfo_s->inputLatency, _cur_input_latency);
+	printf("PA Output Latency %.1fms  %d spl\n", 1e3 * nfo_s->outputLatency, _cur_output_latency);
+#endif
+
+	_state = 0;
+
+	if (_capture_channels > 0) {
+		_input_buffer = (float*) malloc (samples_per_period * _capture_channels * sizeof(float));
+		if (!_input_buffer) {
+			fprintf(stderr, "PortAudio failed to allocate input buffer.\n");
+			pcm_stop();
+			goto error;
+		}
+	}
+
+	if (_playback_channels > 0) {
+		_output_buffer = (float*) calloc (samples_per_period * _playback_channels, sizeof(float));
+		if (!_output_buffer) {
+			fprintf(stderr, "PortAudio failed to allocate output buffer.\n");
+			pcm_stop();
+			goto error;
+		}
+	}
+
+	return 0;
+
+error:
+	_capture_channels = 0;
+	_playback_channels = 0;
+	free (_input_buffer); _input_buffer = NULL;
+	free (_output_buffer); _output_buffer = NULL;
+	Pa_Terminate();
+	return -1;
+}
+
+int
+PortAudioIO::next_cycle (uint32_t n_samples)
+{
+	bool xrun = false;
+	PaError err;
+	err = Pa_IsStreamActive (_stream);
+	if (err != 1) {
+		//   0: inactive / aborted
+		// < 0: error
+		return -1;
+	}
+
+	// TODO, check drift..  process part with larger capacity first.
+	// Pa_GetStreamReadAvailable(_stream) < Pa_GetStreamWriteAvailable(_stream)
+
+	if (_playback_channels > 0) {
+		err = Pa_WriteStream (_stream, _output_buffer, n_samples);
+		if (err) xrun = true;
+	}
+
+	if (_capture_channels > 0) {
+		err = Pa_ReadStream (_stream, _input_buffer, n_samples);
+		if (err) {
+			memset (_input_buffer, 0, sizeof(float) * n_samples * _capture_channels);
+			xrun = true;
+		}
+	}
+
+
+	return xrun ? 1 : 0;
+}
+
+int
+PortAudioIO::get_capture_channel (uint32_t chn, float *input, uint32_t n_samples)
+{
+	assert(chn < _capture_channels);
+	const uint32_t stride = _capture_channels;
+	float *ptr = _input_buffer + chn;
+	while (n_samples-- > 0) {
+		*input++ = *ptr;
+		ptr += stride;
+	}
+	return 0;
+}
+
+int
+PortAudioIO::set_playback_channel (uint32_t chn, const float *output, uint32_t n_samples)
+{
+	assert(chn < _playback_channels);
+	const uint32_t stride = _playback_channels;
+	float *ptr = _output_buffer + chn;
+	while (n_samples-- > 0) {
+		*ptr = *output++;
+		ptr += stride;
+	}
+	return 0;
+}

libs/backends/portaudio/portaudio_io.h

@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2015 Robin Gareus <robin@gareus.org>
+ *
+ * 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 __libbackend_portaudio_pcmio_h__
+#define __libbackend_portaudio_pcmio_h__
+
+#include <map>
+#include <vector>
+#include <string>
+#include <boost/shared_ptr.hpp>
+
+#include <stdint.h>
+
+#include <portaudio.h>
+
+namespace ARDOUR {
+
+class PortAudioIO {
+public:
+	PortAudioIO (void);
+	~PortAudioIO (void);
+
+	int      state (void) const { return _state; }
+
+	void     discover();
+	void     device_list (std::map<int, std::string> &devices) const;
+
+	int      available_sample_rates (int device_id, std::vector<float>& sampleRates);
+	int      available_buffer_sizes (int device_id, std::vector<uint32_t>& sampleRates);
+
+
+	void     pcm_stop (void);
+	int      pcm_start (void);
+
+	int      pcm_setup (
+			int device_input,
+			int device_output,
+			double   sample_rate,
+			uint32_t samples_per_period
+			);
+
+	uint32_t n_playback_channels (void) const { return _playback_channels; }
+	uint32_t n_capture_channels (void) const { return _capture_channels; }
+
+	double   sample_rate (void) const { return _cur_sample_rate; }
+	uint32_t capture_latency (void) const { return _cur_input_latency; }
+	uint32_t playback_latency (void) const { return _cur_output_latency; }
+	double   stream_time(void) const { if (_stream) return Pa_GetStreamTime (_stream); return 0; }
+
+	int      next_cycle(uint32_t n_samples);
+	int      get_capture_channel (uint32_t chn, float *input, uint32_t n_samples);
+	int      set_playback_channel (uint32_t chn, const float *input, uint32_t n_samples);
+
+private:
+	int  _state;
+	bool _initialized;
+
+	uint32_t _capture_channels;
+	uint32_t _playback_channels;
+
+	PaStream *_stream;
+
+	float *_input_buffer;
+	float *_output_buffer;
+
+	double _cur_sample_rate;
+	uint32_t _cur_input_latency;
+	uint32_t _cur_output_latency;
+
+
+	struct paDevice {
+		std::string name;
+		uint32_t n_inputs;
+		uint32_t n_outputs;
+
+		paDevice (std::string n, uint32_t i, uint32_t o)
+			: name (n)
+			, n_inputs (i)
+			, n_outputs (o)
+		{}
+	};
+
+	std::map<int, paDevice *> _devices;
+};
+
+} // namespace
+
+#endif /* __libbackend_portaudio_pcmio_h__ */

libs/backends/portaudio/rt_thread.h

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2014 Robin Gareus <robin@gareus.org>
+ *
+ * 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 __libbackend_portaudio_rthread_h__
+#define __libbackend_portaudio_rthread_h__
+
+#include <pthread.h>
+#include <sched.h>
+
+static int
+_realtime_pthread_create (
+		const int policy, int priority, const size_t stacksize,
+		pthread_t *thread,
+		void *(*start_routine) (void *),
+		void *arg)
+{
+	int rv;
+
+	pthread_attr_t attr;
+	struct sched_param parm;
+
+	const int p_min = sched_get_priority_min (policy);
+	const int p_max = sched_get_priority_max (policy);
+	priority += p_max;
+	if (priority > p_max) priority = p_max;
+	if (priority < p_min) priority = p_min;
+	parm.sched_priority = priority;
+
+	pthread_attr_init (&attr);
+	pthread_attr_setschedpolicy (&attr, policy);
+	pthread_attr_setschedparam (&attr, &parm);
+	pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
+	pthread_attr_setinheritsched (&attr, PTHREAD_EXPLICIT_SCHED);
+	pthread_attr_setstacksize (&attr, stacksize);
+	rv = pthread_create (thread, &attr, start_routine, arg);
+	pthread_attr_destroy (&attr);
+	return rv;
+}
+
+#endif

libs/backends/portaudio/wscript

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+from waflib.extras import autowaf as autowaf
+from waflib import Options
+import os
+import sys
+import re
+
+I18N_PACKAGE = 'portaudio-backend'
+
+# Mandatory variables
+top = '.'
+out = 'build'
+
+def options(opt):
+    autowaf.set_options(opt)
+
+def configure(conf):
+    autowaf.configure(conf)
+    autowaf.check_pkg(conf, 'portaudio-2.0', uselib_store='PORTAUDIO', atleast_version='19')
+
+def build(bld):
+    obj = bld(features = 'cxx cxxshlib')
+    obj.source = [ 'portaudio_backend.cc',
+                   'portaudio_io.cc',
+#                  'portmidi_io.cc'
+                 ]
+    obj.includes = ['.']
+    obj.name     = 'portaudio_backend'
+    obj.target   = 'portaudio_backend'
+    obj.use      = 'libardour libpbd'
+    obj.uselib   = ['PORTAUDIO']
+    obj.install_path  = os.path.join(bld.env['LIBDIR'], 'backends')
+    obj.defines = ['PACKAGE="' + I18N_PACKAGE + '"',
+                   'ARDOURBACKEND_DLL_EXPORTS'
+                  ]