Add host api/driver selection to PortaudioBackend

4 files changed, 107 insertions, 14 deletions

diff --git a/libs/backends/portaudio/portaudio_backend.cc b/libs/backends/portaudio/portaudio_backend.cc
index 0277ca1270..3e24ff28f0 100644
--- a/libs/backends/portaudio/portaudio_backend.cc
+++ b/libs/backends/portaudio/portaudio_backend.cc
@@ -89,10 +89,37 @@ PortAudioBackend::is_realtime () const
 	return true;
 }
 
+bool
+PortAudioBackend::requires_driver_selection() const
+{
+	// we could do this but implementation would need changing
+	/*
+	if (enumerate_drivers().size() == 1) {
+		return false;
+	}
+	*/
+	return true;
+}
+
+std::vector<std::string>
+PortAudioBackend::enumerate_drivers () const
+{
+	std::vector<std::string> currently_available;
+	_pcmio->host_api_list (currently_available);
+	return currently_available;
+}
+
+int
+PortAudioBackend::set_driver (const std::string& name)
+{
+	_target_driver = name;
+	return 0;
+}
+
 std::vector<AudioBackend::DeviceStatus>
 PortAudioBackend::enumerate_devices () const
 {
-	_pcmio->discover();
+	_pcmio->discover(_target_driver);
 	_audio_device_status.clear();
 	std::map<int, std::string> devices;
 	_pcmio->device_list(devices);
diff --git a/libs/backends/portaudio/portaudio_backend.h b/libs/backends/portaudio/portaudio_backend.h
index 36aebe0f14..432598263d 100644
--- a/libs/backends/portaudio/portaudio_backend.h
+++ b/libs/backends/portaudio/portaudio_backend.h
@@ -160,6 +160,10 @@ class PortAudioBackend : public AudioBackend {
 		std::string name () const;
 		bool is_realtime () const;
 
+		bool requires_driver_selection() const;
+		std::vector<std::string> enumerate_drivers () const;
+		int set_driver (const std::string&);
+
 		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;
@@ -313,6 +317,7 @@ class PortAudioBackend : public AudioBackend {
 		static std::vector<AudioBackend::DeviceStatus> _audio_device_status;
 		static std::vector<AudioBackend::DeviceStatus> _midi_device_status;
 
+		std::string  _target_driver;
 		mutable std::string _audio_device;
 		std::string _midi_driver_option;
 
diff --git a/libs/backends/portaudio/portaudio_io.cc b/libs/backends/portaudio/portaudio_io.cc
index d8a7fc9cf1..0b2256496d 100644
--- a/libs/backends/portaudio/portaudio_io.cc
+++ b/libs/backends/portaudio/portaudio_io.cc
@@ -133,28 +133,80 @@ PortAudioIO::device_list (std::map<int, std::string> &devices) const {
 	}
 }
 
-void
-PortAudioIO::discover()
+bool
+PortAudioIO::initialize_pa ()
 {
-	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 false;
+		}
+		_initialized = true;
 	}
-	if (err != paNoError) {
-		return;
+
+	return true;
+}
+
+void
+PortAudioIO::host_api_list (std::vector<std::string>& api_list)
+{
+	if (!initialize_pa()) return;
+
+	PaHostApiIndex count = Pa_GetHostApiCount();
+
+	if (count < 0) return;
+
+	for (int i = 0; i < count; ++i) {
+		const PaHostApiInfo* info = Pa_GetHostApiInfo (i);
+		if (info->name != NULL) { // possible?
+			api_list.push_back (info->name);
+		}
 	}
+}
 
-	_initialized = true;
+PaHostApiIndex
+PortAudioIO::get_host_api_index_from_name (const std::string& name)
+{
+	if (!initialize_pa()) return -1;
+
+	PaHostApiIndex count = Pa_GetHostApiCount();
+
+	if (count < 0) return -1;
+
+	for (int i = 0; i < count; ++i) {
+		const PaHostApiInfo* info = Pa_GetHostApiInfo (i);
+		if (info->name != NULL) { // possible?
+			if (name == info->name) return i;
+		}
+	}
+	return -1;
+}
+
+void
+PortAudioIO::discover(const std::string& host_api)
+{
+	if (!initialize_pa()) return;
+
+	for (std::map<int, paDevice*>::const_iterator i = _devices.begin (); i != _devices.end(); ++i) {
+		delete i->second;
+	}
+	_devices.clear();
+
+	PaHostApiIndex host_api_index = get_host_api_index_from_name (host_api);
+
+	if (host_api_index < 0) return;
+
+	const PaHostApiInfo* info = Pa_GetHostApiInfo (host_api_index);
+
+	if (info == NULL) return;
+	PaDeviceIndex default_input = info->defaultInputDevice;
+	PaDeviceIndex default_output = info->defaultOutputDevice;
 
 	{
-		const PaDeviceInfo* nfo_i = Pa_GetDeviceInfo(Pa_GetDefaultInputDevice());
-		const PaDeviceInfo* nfo_o = Pa_GetDeviceInfo(Pa_GetDefaultOutputDevice());
+		const PaDeviceInfo* nfo_i = Pa_GetDeviceInfo(default_input);
+		const PaDeviceInfo* nfo_o = Pa_GetDeviceInfo(default_output);
 		if (nfo_i && nfo_o) {
 			_devices.insert (std::pair<int, paDevice*> (-1,
 						new paDevice("Default",
@@ -171,7 +223,9 @@ PortAudioIO::discover()
 
 	for (int i = 0 ; i < n_devices; ++i) {
 		const PaDeviceInfo* nfo = Pa_GetDeviceInfo(i);
+
 		if (!nfo) continue;
+		if (nfo->hostApi != host_api_index) continue;
 #ifndef NDEBUG
 		printf(" (%d) '%s' in: %d (lat: %.1f .. %.1f) out: %d (lat: %.1f .. %.1f) sr:%.2f\n",
 				i, nfo->name,
diff --git a/libs/backends/portaudio/portaudio_io.h b/libs/backends/portaudio/portaudio_io.h
index 532dc66df6..bbc3f9a4d0 100644
--- a/libs/backends/portaudio/portaudio_io.h
+++ b/libs/backends/portaudio/portaudio_io.h
@@ -37,7 +37,12 @@ public:
 
 	int      state (void) const { return _state; }
 
-	void     discover();
+	bool     initialize_pa ();
+
+	void     host_api_list (std::vector<std::string>&);
+	PaHostApiIndex get_host_api_index_from_name (const std::string& name);
+
+	void     discover(const std::string& host_api);
 	void     device_list (std::map<int, std::string> &devices) const;
 
 	int      available_sample_rates (int device_id, std::vector<float>& sampleRates);
@@ -96,6 +101,8 @@ private:
 	};
 
 	std::map<int, paDevice *> _devices;
+
+	std::string _host_api;
 };
 
 } // namespace