4 files changed, 121 insertions, 0 deletions
diff --git a/src/ipa/rkisp1/algorithms/lux.cpp b/src/ipa/rkisp1/algorithms/lux.cpp
new file mode 100644
index 00000000..b0f74963
--- /dev/null
+++ b/src/ipa/rkisp1/algorithms/lux.cpp
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board
+ *
+ * lux.cpp - RkISP1 Lux control
+ */
+
+#include "lux.h"
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/control_ids.h>
+
+#include "libipa/histogram.h"
+#include "libipa/lux.h"
+
+/**
+ * \file lux.h
+ */
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+/**
+ * \class Lux
+ * \brief RkISP1 Lux control
+ *
+ * The Lux algorithm is responsible for estimating the lux level of the image.
+ * It doesn't take or generate any controls, but it provides a lux level for
+ * other algorithms (such as AGC) to use.
+ */
+
+/**
+ * \brief Construct an rkisp1 Lux algo module
+ *
+ * The Lux helper is initialized to 65535 as that is the max bin count on the
+ * rkisp1.
+ */
+Lux::Lux()
+	: lux_(65535)
+{
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::init
+ */
+int Lux::init([[maybe_unused]] IPAContext &context, const YamlObject &tuningData)
+{
+	return lux_.parseTuningData(tuningData);
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::process
+ */
+void Lux::process(IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  const rkisp1_stat_buffer *stats,
+		  ControlList &metadata)
+{
+	utils::Duration exposureTime = context.configuration.sensor.lineDuration
+				     * frameContext.sensor.exposure;
+	double gain = frameContext.sensor.gain;
+
+	/* \todo Deduplicate the histogram calculation from AGC */
+	const rkisp1_cif_isp_stat *params = &stats->params;
+	Histogram yHist({ params->hist.hist_bins, context.hw->numHistogramBins },
+			[](uint32_t x) { return x >> 4; });
+
+	double lux = lux_.estimateLux(exposureTime, gain, 1.0, yHist);
+	frameContext.lux.lux = lux;
+	metadata.set(controls::Lux, lux);
+}
+
+REGISTER_IPA_ALGORITHM(Lux, "Lux")
+
+} /* namespace ipa::rkisp1::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/rkisp1/algorithms/lux.h b/src/ipa/rkisp1/algorithms/lux.h
new file mode 100644
index 00000000..8a90de55
--- /dev/null
+++ b/src/ipa/rkisp1/algorithms/lux.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board
+ *
+ * lux.h - RkISP1 Lux control
+ */
+
+#pragma once
+
+#include <sys/types.h>
+
+#include "libipa/lux.h"
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+class Lux : public Algorithm
+{
+public:
+	Lux();
+
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const rkisp1_stat_buffer *stats,
+		     ControlList &metadata) override;
+
+private:
+	ipa::Lux lux_;
+};
+
+} /* namespace ipa::rkisp1::algorithms */
+} /* namespace libcamera */
diff --git a/src/ipa/rkisp1/algorithms/meson.build b/src/ipa/rkisp1/algorithms/meson.build
index 1734a667..c66b0b70 100644
--- a/src/ipa/rkisp1/algorithms/meson.build
+++ b/src/ipa/rkisp1/algorithms/meson.build
@@ -12,4 +12,5 @@ rkisp1_ipa_algorithms = files([
     'goc.cpp',
     'gsl.cpp',
     'lsc.cpp',
+    'lux.cpp',
 ])
diff --git a/src/ipa/rkisp1/ipa_context.h b/src/ipa/rkisp1/ipa_context.h
index 4b50015b..b83c1822 100644
--- a/src/ipa/rkisp1/ipa_context.h
+++ b/src/ipa/rkisp1/ipa_context.h
@@ -169,6 +169,10 @@ struct IPAFrameContext : public FrameContext {
 	struct {
 		Matrix<float, 3, 3> ccm;
 	} ccm;
+
+	struct {
+		double lux;
+	} lux;
 };
 
 struct IPAContext {