1 files changed, 115 insertions, 0 deletions
diff --git a/src/ipa/rpi/controller/rpi/lux.cpp b/src/ipa/rpi/controller/rpi/lux.cpp
new file mode 100644
index 00000000..06625f3a
--- /dev/null
+++ b/src/ipa/rpi/controller/rpi/lux.cpp
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * lux.cpp - Lux control algorithm
+ */
+#include <math.h>
+
+#include <libcamera/base/log.h>
+
+#include "../device_status.h"
+
+#include "lux.h"
+
+using namespace RPiController;
+using namespace libcamera;
+using namespace std::literals::chrono_literals;
+
+LOG_DEFINE_CATEGORY(RPiLux)
+
+#define NAME "rpi.lux"
+
+Lux::Lux(Controller *controller)
+	: Algorithm(controller)
+{
+	/*
+	 * Put in some defaults as there will be no meaningful values until
+	 * Process has run.
+	 */
+	status_.aperture = 1.0;
+	status_.lux = 400;
+}
+
+char const *Lux::name() const
+{
+	return NAME;
+}
+
+int Lux::read(const libcamera::YamlObject &params)
+{
+	auto value = params["reference_shutter_speed"].get<double>();
+	if (!value)
+		return -EINVAL;
+	referenceShutterSpeed_ = *value * 1.0us;
+
+	value = params["reference_gain"].get<double>();
+	if (!value)
+		return -EINVAL;
+	referenceGain_ = *value;
+
+	referenceAperture_ = params["reference_aperture"].get<double>(1.0);
+
+	value = params["reference_Y"].get<double>();
+	if (!value)
+		return -EINVAL;
+	referenceY_ = *value;
+
+	value = params["reference_lux"].get<double>();
+	if (!value)
+		return -EINVAL;
+	referenceLux_ = *value;
+
+	currentAperture_ = referenceAperture_;
+	return 0;
+}
+
+void Lux::setCurrentAperture(double aperture)
+{
+	currentAperture_ = aperture;
+}
+
+void Lux::prepare(Metadata *imageMetadata)
+{
+	std::unique_lock<std::mutex> lock(mutex_);
+	imageMetadata->set("lux.status", status_);
+}
+
+void Lux::process(StatisticsPtr &stats, Metadata *imageMetadata)
+{
+	DeviceStatus deviceStatus;
+	if (imageMetadata->get("device.status", deviceStatus) == 0) {
+		double currentGain = deviceStatus.analogueGain;
+		double currentAperture = deviceStatus.aperture.value_or(currentAperture_);
+		double currentY = stats->yHist.interQuantileMean(0, 1);
+		double gainRatio = referenceGain_ / currentGain;
+		double shutterSpeedRatio =
+			referenceShutterSpeed_ / deviceStatus.shutterSpeed;
+		double apertureRatio = referenceAperture_ / currentAperture;
+		double yRatio = currentY * (65536 / stats->yHist.bins()) / referenceY_;
+		double estimatedLux = shutterSpeedRatio * gainRatio *
+				      apertureRatio * apertureRatio *
+				      yRatio * referenceLux_;
+		LuxStatus status;
+		status.lux = estimatedLux;
+		status.aperture = currentAperture;
+		LOG(RPiLux, Debug) << ": estimated lux " << estimatedLux;
+		{
+			std::unique_lock<std::mutex> lock(mutex_);
+			status_ = status;
+		}
+		/*
+		 * Overwrite the metadata here as well, so that downstream
+		 * algorithms get the latest value.
+		 */
+		imageMetadata->set("lux.status", status);
+	} else
+		LOG(RPiLux, Warning) << ": no device metadata";
+}
+
+/* Register algorithm with the system. */
+static Algorithm *create(Controller *controller)
+{
+	return (Algorithm *)new Lux(controller);
+}
+static RegisterAlgorithm reg(NAME, &create);