ipa: rpi: pisp: Add decompand support using PiSP hardware block

src/ipa/rpi/controller/decompand_status.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include "libipa/pwl.h"
+
+struct DecompandStatus {
+	uint32_t bitdepth;
+	libcamera::ipa::Pwl decompandCurve;
+};

src/ipa/rpi/controller/meson.build

@@ -14,6 +14,7 @@ rpi_ipa_controller_sources = files([
     'rpi/cac.cpp',
     'rpi/ccm.cpp',
     'rpi/contrast.cpp',
+    'rpi/decompand.cpp',
     'rpi/denoise.cpp',
     'rpi/dpc.cpp',
     'rpi/geq.cpp',

src/ipa/rpi/controller/rpi/decompand.cpp

@@ -0,0 +1,58 @@
+#include "decompand.h"
+
+#include <libcamera/base/log.h>
+
+#include "../decompand_status.h"
+#include "../histogram.h"
+
+using namespace RPiController;
+using namespace libcamera;
+
+LOG_DEFINE_CATEGORY(RPiDecompand)
+
+#define NAME "rpi.decompand"
+
+Decompand::Decompand(Controller *controller)
+	: Algorithm(controller)
+{
+}
+
+char const *Decompand::name() const
+{
+	return NAME;
+}
+
+int Decompand::read(const libcamera::YamlObject &params)
+{
+	config_.bitdepth = params["bitdepth"].get<uint32_t>(0);
+	config_.decompandCurve = params["decompand_curve"].get<ipa::Pwl>(ipa::Pwl{});
+	return config_.decompandCurve.empty() ? -EINVAL : 0;
+}
+
+void Decompand::initialise()
+{
+}
+
+void Decompand::switchMode([[maybe_unused]] CameraMode const &cameraMode,
+			   [[maybe_unused]] Metadata *metadata)
+{
+	mode_ = cameraMode;
+}
+
+void Decompand::prepare(Metadata *imageMetadata)
+{
+	DecompandStatus decompandStatus;
+
+	if (config_.bitdepth == 0 || mode_.bitdepth == config_.bitdepth) {
+		decompandStatus.decompandCurve = config_.decompandCurve;
+		imageMetadata->set("decompand.status", decompandStatus);
+	}
+}
+
+/* Register algorithm with the system. */
+static Algorithm *create(Controller *controller)
+{
+	return (Algorithm *)new Decompand(controller);
+}
+
+static RegisterAlgorithm reg(NAME, &create);

src/ipa/rpi/controller/rpi/decompand.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <libipa/pwl.h>
+#include "algorithm.h"
+
+#include "../decompand_status.h"
+
+namespace RPiController {
+
+struct DecompandConfig {
+	uint32_t bitdepth;
+	libcamera::ipa::Pwl decompandCurve;
+};
+
+class Decompand : public Algorithm
+{
+public:
+	Decompand(Controller *controller = NULL);
+	char const *name() const override;
+	int read(const libcamera::YamlObject &params) override;
+	void initialise() override;
+	void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
+	void prepare(Metadata *imageMetadata) override;
+
+private:
+	CameraMode mode_;
+	DecompandConfig config_;
+};
+
+} /* namespace RPiController */