ipa: ipu3: Introduce a modular tone mapping algorithm

Introduce a new algorithm to manage the tone mapping handling of the
IPU3.

The initial algorithm is chosen to configure the gamma contrast curve
which moves the implementation out of AWB for simplicity. As it is
initialised with a default gamma value of 1.1, there is no need to use
the default table at initialisation anymore.

This demonstrates the way to use process() call when the EventStatReady
comes in. The function calculates the LUT in the context of a frame, and
when prepare() is called, the parameters are filled with the updated
values.

AGC is modified to take the new process interface into account.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/src/ipa/ipu3/algorithms/tone_mapping.h b/src/ipa/ipu3/algorithms/tone_mapping.h
new file mode 100644
index 00000000..1dae4f9a
--- /dev/null
+++ b/src/ipa/ipu3/algorithms/tone_mapping.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google inc.
+ *
+ * tone_mapping.h - IPU3 ToneMapping and Gamma control
+ */
+#ifndef __LIBCAMERA_IPU3_ALGORITHMS_TONE_MAPPING_H__
+#define __LIBCAMERA_IPU3_ALGORITHMS_TONE_MAPPING_H__
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::ipu3::algorithms {
+
+class ToneMapping : public Algorithm
+{
+public:
+	ToneMapping();
+
+	void prepare(IPAContext &context, ipu3_uapi_params *params) override;
+	void process(IPAContext &context, const ipu3_uapi_stats_3a *stats) override;
+
+private:
+	double gamma_;
+};
+
+} /* namespace ipa::ipu3::algorithms */
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_IPU3_ALGORITHMS_TONE_MAPPING_H__ */