1 files changed, 60 insertions, 0 deletions
diff --git a/src/ipa/ipu3/algorithms/tone_mapping.cpp b/src/ipa/ipu3/algorithms/tone_mapping.cpp
new file mode 100644
index 00000000..3af96261
--- /dev/null
+++ b/src/ipa/ipu3/algorithms/tone_mapping.cpp
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google inc.
+ *
+ * tone_mapping.cpp - IPU3 ToneMapping and Gamma control
+ */
+
+#include "tone_mapping.h"
+
+#include <cmath>
+#include <string.h>
+
+namespace libcamera {
+
+namespace ipa::ipu3::algorithms {
+
+ToneMapping::ToneMapping()
+	: gamma_(1.0)
+{
+}
+
+void ToneMapping::prepare([[maybe_unused]] IPAContext &context,
+			  ipu3_uapi_params *params)
+{
+	/* Copy the calculated LUT into the parameters buffer. */
+	memcpy(params->acc_param.gamma.gc_lut.lut,
+	       context.frameContext.toneMapping.gammaCorrection.lut,
+	       IPU3_UAPI_GAMMA_CORR_LUT_ENTRIES *
+	       sizeof(params->acc_param.gamma.gc_lut.lut[0]));
+
+	/* Enable the custom gamma table. */
+	params->use.acc_gamma = 1;
+	params->acc_param.gamma.gc_ctrl.enable = 1;
+}
+
+void ToneMapping::process([[maybe_unused]] IPAContext &context,
+			  [[maybe_unused]] const ipu3_uapi_stats_3a *stats)
+{
+	/*
+	 * Hardcode gamma to 1.1 as a default for now.
+	 *
+	 * \todo Expose gamma control setting through the libcamera control API
+	 */
+	gamma_ = 1.1;
+
+	struct ipu3_uapi_gamma_corr_lut &lut =
+		context.frameContext.toneMapping.gammaCorrection;
+
+	for (uint32_t i = 0; i < std::size(lut.lut); i++) {
+		double j = static_cast<double>(i) / (std::size(lut.lut) - 1);
+		double gamma = std::pow(j, 1.0 / gamma_);
+
+		/* The output value is expressed on 13 bits. */
+		lut.lut[i] = gamma * 8191;
+	}
+}
+
+} /* namespace ipa::ipu3::algorithms */
+
+} /* namespace libcamera */