1 files changed, 57 insertions, 0 deletions
diff --git a/src/ipa/rkisp1/algorithms/blc.cpp b/src/ipa/rkisp1/algorithms/blc.cpp
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+++ b/src/ipa/rkisp1/algorithms/blc.cpp
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+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021-2022, Ideas On Board
+ *
+ * blc.cpp - RkISP1 Black Level Correction control
+ */
+
+#include "blc.h"
+
+/**
+ * \file blc.h
+ */
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+/**
+ * \class BlackLevelCorrection
+ * \brief RkISP1 Black Level Correction control
+ *
+ * The pixels output by the camera normally include a black level, because
+ * sensors do not always report a signal level of '0' for black. Pixels at or
+ * below this level should be considered black. To achieve that, the RkISP BLC
+ * algorithm subtracts a configurable offset from all pixels.
+ *
+ * The black level can be measured at runtime from an optical dark region of the
+ * camera sensor, or measured during the camera tuning process. The first option
+ * isn't currently supported.
+ */
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::prepare
+ */
+void BlackLevelCorrection::prepare(IPAContext &context,
+				   rkisp1_params_cfg *params)
+{
+	if (context.frameContext.frameCount > 0)
+		return;
+	/*
+	 * Substract fixed values taken from imx219 tuning file.
+	 * \todo Use a configuration file for it ?
+	 */
+	params->others.bls_config.enable_auto = 0;
+	params->others.bls_config.fixed_val.r = 256;
+	params->others.bls_config.fixed_val.gr = 256;
+	params->others.bls_config.fixed_val.gb = 256;
+	params->others.bls_config.fixed_val.b = 256;
+
+	params->module_en_update |= RKISP1_CIF_ISP_MODULE_BLS;
+	params->module_ens |= RKISP1_CIF_ISP_MODULE_BLS;
+	params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_BLS;
+}
+
+} /* namespace ipa::rkisp1::algorithms */
+
+} /* namespace libcamera */