Use ASIO specific device channel names for port properties/pretty names

libs/backends/portaudio/portaudio_backend.cc

@@ -792,6 +792,28 @@ PortAudioBackend::get_port_name (PortEngine::PortHandle port) const
 	return static_cast<PamPort*>(port)->name ();
 }
 
+int
+PortAudioBackend::get_port_property (PortHandle port,
+                                     const std::string& key,
+                                     std::string& value,
+                                     std::string& type) const
+{
+	if (!valid_port (port)) {
+		PBD::error << _ ("PortAudioBackend::get_port_name: Invalid Port(s)")
+		           << endmsg;
+		return -1;
+	}
+
+	if (key == "http://jackaudio.org/metadata/pretty-name") {
+		type = "";
+		value = static_cast<PamPort*>(port)->pretty_name ();
+		if (!value.empty()) {
+			return 0;
+		}
+	}
+	return -1;
+}
+
 PortEngine::PortHandle
 PortAudioBackend::get_port_by_name (const std::string& name) const
 {
@@ -915,7 +937,10 @@ PortAudioBackend::register_system_audio_ports()
 		PortHandle p = add_port(std::string(tmp), DataType::AUDIO, static_cast<PortFlags>(IsOutput | IsPhysical | IsTerminal));
 		if (!p) return -1;
 		set_latency_range (p, false, lr);
-		_system_inputs.push_back(static_cast<PortAudioPort*>(p));
+		PortAudioPort* audio_port = static_cast<PortAudioPort*>(p);
+		audio_port->set_pretty_name (
+		    _pcmio->get_input_channel_name (name_to_id (_input_audio_device), i));
+		_system_inputs.push_back (audio_port);
 	}
 
 	lr.min = lr.max = portaudio_reported_output_latency + (_measure_latency ? 0 : _systemic_audio_output_latency);
@@ -925,7 +950,10 @@ PortAudioBackend::register_system_audio_ports()
 		PortHandle p = add_port(std::string(tmp), DataType::AUDIO, static_cast<PortFlags>(IsInput | IsPhysical | IsTerminal));
 		if (!p) return -1;
 		set_latency_range (p, true, lr);
-		_system_outputs.push_back(static_cast<PamPort*>(p));
+		PortAudioPort* audio_port = static_cast<PortAudioPort*>(p);
+		audio_port->set_pretty_name (
+		    _pcmio->get_output_channel_name (name_to_id (_output_audio_device), i));
+		_system_outputs.push_back(audio_port);
 	}
 	return 0;
 }

libs/backends/portaudio/portaudio_backend.h

@@ -65,9 +65,11 @@ class PamPort { // PortAudio / PortMidi Backend Port
 		virtual ~PamPort ();
 
 		const std::string& name () const { return _name; }
+		const std::string& pretty_name () const { return _pretty_name; }
 		PortFlags flags () const { return _flags; }
 
 		int set_name (const std::string &name) { _name = name; return 0; }
+		int set_pretty_name (const std::string& name) { _pretty_name = name; return 0;}
 
 		virtual DataType type () const = 0;
 
@@ -107,6 +109,7 @@ class PamPort { // PortAudio / PortMidi Backend Port
 	private:
 		PortAudioBackend &_osx_backend;
 		std::string _name;
+		std::string _pretty_name;
 		const PortFlags _flags;
 		LatencyRange _capture_latency_range;
 		LatencyRange _playback_latency_range;
@@ -261,6 +264,7 @@ class PortAudioBackend : public AudioBackend {
 		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_port_property (PortHandle, const std::string& key, std::string& value, std::string& type) const;
 
 		int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>&) const;
 

libs/backends/portaudio/portaudio_io.cc

@@ -737,6 +737,47 @@ PortAudioIO::next_cycle (uint32_t n_samples)
 	return xrun ? 1 : 0;
 }
 
+std::string
+PortAudioIO::get_input_channel_name (int device_id, uint32_t channel) const
+{
+#ifdef WITH_ASIO
+	const char* channel_name;
+
+	// This will return an error for non-ASIO devices so no need to check if
+	// the device_id corresponds to an ASIO device.
+	PaError err = PaAsio_GetInputChannelName (device_id, channel, &channel_name);
+
+	if (err == paNoError) {
+		DEBUG_AUDIO (
+		    string_compose ("Input channel name for device %1, channel %2 is %3\n",
+		                    device_id,
+		                    channel,
+		                    channel_name));
+		return channel_name;
+	}
+#endif
+	return std::string();
+}
+
+std::string
+PortAudioIO::get_output_channel_name (int device_id, uint32_t channel) const
+{
+#ifdef WITH_ASIO
+	const char* channel_name;
+
+	PaError err = PaAsio_GetOutputChannelName (device_id, channel, &channel_name);
+
+	if (err == paNoError) {
+		DEBUG_AUDIO (
+		    string_compose ("Output channel name for device %1, channel %2 is %3\n",
+		                    device_id,
+		                    channel,
+		                    channel_name));
+		return channel_name;
+	}
+#endif
+	return std::string();
+}
 
 #ifdef INTERLEAVED_INPUT
 

libs/backends/portaudio/portaudio_io.h

@@ -81,6 +81,9 @@ public:
 	uint32_t n_playback_channels (void) const { return _playback_channels; }
 	uint32_t n_capture_channels (void) const { return _capture_channels; }
 
+	std::string get_input_channel_name (int device_id, uint32_t channel) const;
+	std::string get_output_channel_name (int device_id, uint32_t channel) const;
+
 	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; }