new file mode 100644
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * blc.cpp - Mali-C55 sensor offset (black level) correction
+ */
+
+#include "blc.h"
+
+#include <libcamera/base/log.h>
+#include <libcamera/control_ids.h>
+
+#include "libcamera/internal/yaml_parser.h"
+
+/**
+ * \file blc.h
+ */
+
+namespace libcamera {
+
+namespace ipa::mali_c55::algorithms {
+
+/**
+ * \class BlackLevelCorrection
+ * \brief MaliC55 Black Level Correction control
+ *
+ * todo
+ */
+
+LOG_DEFINE_CATEGORY(MaliC55Blc)
+
+BlackLevelCorrection::BlackLevelCorrection()
+ : tuningParameters_(false)
+{
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::init
+ */
+int BlackLevelCorrection::init([[maybe_unused]] IPAContext &context,
+ const YamlObject &tuningData)
+{
+ offset00 = tuningData["offset00"].get<uint32_t>(256);
+ offset01 = tuningData["offset01"].get<uint32_t>(256);
+ offset10 = tuningData["offset10"].get<uint32_t>(256);
+ offset11 = tuningData["offset11"].get<uint32_t>(256);
+
+ if (offset00 > kMaxOffset || offset01 > kMaxOffset ||
+ offset10 > kMaxOffset || offset11 > kMaxOffset) {
+ LOG(MaliC55Blc, Error) << "Invalid black level offsets";
+ return -EINVAL;
+ }
+
+ tuningParameters_ = true;
+
+ LOG(MaliC55Blc, Debug)
+ << "Black levels: 00 " << offset00 << ", 01 " << offset01
+ << ", 10 " << offset10 << ", 11 " << offset11;
+
+ return 0;
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::prepare
+ */
+void BlackLevelCorrection::prepare([[maybe_unused]] IPAContext &context,
+ const uint32_t frame,
+ [[maybe_unused]] IPAFrameContext &frameContext,
+ mali_c55_params_block_header *block)
+{
+ if (frame > 0)
+ return;
+
+ if (!tuningParameters_)
+ return;
+
+ block->type = MALI_C55_PARAM_BLOCK_SENSOR_OFFS;
+ block->enabled = true;
+ block->size = sizeof(mali_c55_params_sensor_off_preshading);
+
+ struct mali_c55_params_sensor_off_preshading *sensor_offs =
+ reinterpret_cast<mali_c55_params_sensor_off_preshading *>(block);
+
+ sensor_offs->chan00 = offset00;
+ sensor_offs->chan01 = offset01;
+ sensor_offs->chan10 = offset10;
+ sensor_offs->chan11 = offset11;
+}
+
+void BlackLevelCorrection::process([[maybe_unused]] IPAContext &context,
+ [[maybe_unused]] const uint32_t frame,
+ [[maybe_unused]] IPAFrameContext &frameContext,
+ [[maybe_unused]] const mali_c55_stats_buffer *stats,
+ ControlList &metadata)
+{
+ /*
+ * Black Level Offsets in tuning data need to be 20-bit, whereas the
+ * metadata expects values from a 16-bit range. Right-shift to remove
+ * the 4 least significant bits.
+ *
+ * The black levels should be reported in the order R, Gr, Gb, B. We
+ * ignore that here given we're using matching values so far, but it
+ * would be safer to check the sensor's bayer order.
+ *
+ * \todo Account for bayer order.
+ */
+ metadata.set(controls::SensorBlackLevels, {
+ static_cast<int32_t>(offset00 >> 4),
+ static_cast<int32_t>(offset01 >> 4),
+ static_cast<int32_t>(offset10 >> 4),
+ static_cast<int32_t>(offset11 >> 4),
+ });
+}
+
+REGISTER_IPA_ALGORITHM(BlackLevelCorrection, "BlackLevelCorrection")
+
+} /* namespace ipa::mali_c55::algorithms */
+
+} /* namespace libcamera */
new file mode 100644
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * blc.h - Mali-C55 sensor offset (black level) correction
+ */
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::mali_c55::algorithms {
+
+class BlackLevelCorrection : public Algorithm
+{
+public:
+ BlackLevelCorrection();
+ ~BlackLevelCorrection() = default;
+
+ int init(IPAContext &context, const YamlObject &tuningData) override;
+ void prepare(IPAContext &context, const uint32_t frame,
+ IPAFrameContext &frameContext,
+ mali_c55_params_block_header *block) override;
+ void process(IPAContext &context, const uint32_t frame,
+ IPAFrameContext &frameContext,
+ const mali_c55_stats_buffer *stats,
+ ControlList &metadata) override;
+
+private:
+ static constexpr uint32_t kMaxOffset = 0xfffff;
+
+ bool tuningParameters_;
+ uint32_t offset00;
+ uint32_t offset01;
+ uint32_t offset10;
+ uint32_t offset11;
+};
+
+} /* namespace ipa::mali_c55::algorithms */
+} /* namespace libcamera */
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: CC0-1.0
mali_c55_ipa_algorithms = files([
+ 'blc.cpp',
])