1 files changed, 129 insertions, 0 deletions
diff --git a/src/audiomixer-service.cpp b/src/audiomixer-service.cpp
new file mode 100644
index 0000000..5787153
--- /dev/null
+++ b/src/audiomixer-service.cpp
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#include "audiomixer-service.hpp"
+#include <iostream>
+#include <algorithm>
+
+
+AudiomixerService::AudiomixerService(const VisConfig &config, net::io_context& ioc, ssl::context& ctx) :
+	VisSession(config, ioc, ctx)
+{
+	m_audiomixer = audiomixer_new();
+	if (m_audiomixer) {
+		// Set up callbacks for WirePlumber events
+		m_audiomixer_events.controls_changed = audiomixer_control_change_cb;
+		m_audiomixer_events.value_changed = audiomixer_value_change_cb;
+		audiomixer_add_event_listener(m_audiomixer, &m_audiomixer_events, this);
+
+		// Drive connecting to PipeWire core and refreshing controls list
+		audiomixer_lock(m_audiomixer);
+		audiomixer_ensure_controls(m_audiomixer, 3);
+		audiomixer_unlock(m_audiomixer);
+	} else {
+		std::cerr << "Could not create WirePlumber connection" << std::endl;
+	}
+}
+
+AudiomixerService::~AudiomixerService()
+{
+	audiomixer_free(m_audiomixer);
+}
+
+void AudiomixerService::handle_authorized_response(void)
+{
+	subscribe("Vehicle.Cabin.Infotainment.Media.Volume");
+	subscribe("Vehicle.Cabin.SteeringWheel.Switches.VolumeUp");
+	subscribe("Vehicle.Cabin.SteeringWheel.Switches.VolumeDown");
+	subscribe("Vehicle.Cabin.SteeringWheel.Switches.VolumeMute");
+
+	// Set initial volume in VSS
+	// For now a value of 50 matches the default in the homescreen app.
+	// Ideally there would be some form of persistence scheme to restore
+	// the last value on restart.
+	set("Vehicle.Cabin.Infotainment.Media.Volume", "50");
+}
+
+void AudiomixerService::handle_get_response(std::string &path, std::string &value, std::string &timestamp)
+{
+	// Placeholder since no gets are performed ATM
+}
+
+void AudiomixerService::handle_notification(std::string &path, std::string &value, std::string &timestamp)
+{
+	if (!m_audiomixer) {
+		return;
+	}
+
+	audiomixer_lock(m_audiomixer);
+
+	const struct mixer_control *ctl = audiomixer_find_control(m_audiomixer, "Master Playback");
+	if (!ctl) {
+		audiomixer_unlock(m_audiomixer);
+		return;
+	}
+
+	if (path == "Vehicle.Cabin.Infotainment.Media.Volume") {
+		try {
+			int volume = std::stoi(value);
+			if (volume >= 0 && volume <= 100) {
+				double v = (double) volume / 100.0;
+				if (m_config.verbose() > 1)
+					std::cout << "Setting volume to " << v << std::endl;
+				audiomixer_change_volume(m_audiomixer, ctl, v);
+			}
+		}
+		catch (std::exception ex) {
+			// ignore bad value
+		}
+	} else if (path == "Vehicle.Cabin.SteeringWheel.Switches.VolumeUp" && value == "true") {
+		double volume = ctl->volume;
+		volume += 0.05; // up 5%
+		if (volume > 1.0)
+			volume = 1.0; // clamp to 100%
+		if (m_config.verbose() > 1)
+			std::cout << "Increasing volume to " << volume << std::endl;
+		audiomixer_change_volume(m_audiomixer, ctl, volume);
+
+	} else if (path == "Vehicle.Cabin.SteeringWheel.Switches.VolumeDown" && value == "true") {
+		double volume = ctl->volume;
+		volume -= 0.05; // down 5%
+		if (volume < 0.0)
+			volume = 0.0; // clamp to 0%
+		if (m_config.verbose() > 1)
+			std::cout << "Decreasing volume to " << volume << std::endl;
+		audiomixer_change_volume(m_audiomixer, ctl, volume);
+
+	} else if (path == "Vehicle.Cabin.SteeringWheel.Switches.VolumeMute" && value == "true") {
+		if (m_config.verbose() > 1) {
+			if (ctl->mute)
+				std::cout << "Unmuting" << std::endl;
+			else
+				std::cout << "Muting" << std::endl;
+		}
+		audiomixer_change_mute(m_audiomixer, ctl, !ctl->mute);
+	}
+	// else ignore
+
+	audiomixer_unlock(m_audiomixer);
+}
+
+void AudiomixerService::handle_control_change(void)
+{
+	// Ignore for now
+}
+
+void AudiomixerService::handle_value_change(unsigned int change_mask, const struct mixer_control *control)
+{
+	if (!control)
+		return;
+
+	if (change_mask & MIXER_CONTROL_CHANGE_FLAG_VOLUME) {
+		if (std::string(control->name) == "Master Playback") {
+			// Push change into VIS
+			std::string value = std::to_string((int) (control->volume * 100.0));
+			set("Vehicle.Cabin.Infotainment.Media.Volume", value);
+		}
+	} else if (change_mask & MIXER_CONTROL_CHANGE_FLAG_MUTE) {
+		// For now, do nothing, new state is in control->mute
+	}
+}