libcamera: software_isp: Move color mappings out of debayering

Constructing the color mapping tables is related to stats rather than
debayering, where they are applied.  Let's move the corresponding code
to stats processing.

The same applies to the auxiliary gamma table.  As the gamma value is
currently fixed and used in a single place, with the temporary exception
mentioned below, there is no need to share it anywhere anymore.

It's necessary to initialize SoftwareIsp::debayerParams_ to default
values.  These initial values are used for the first two frames, before
they are changed based on determined stats.  To avoid sharing the gamma
value constant in artificial ways, we use 0.5 directly in the
initialization.  This all is not a particularly elegant thing to do,
such a code belongs conceptually to the similar code in stats
processing, but doing better is left for larger refactoring.

This is a preliminary step towards building this functionality on top of
libipa/algorithm.h, which should follow.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Andrei Konovalov <andrey.konovalov.ynk@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/include/libcamera/internal/software_isp/debayer_params.h b/include/libcamera/internal/software_isp/debayer_params.h
index ce1b5945..463d24b3 100644
--- a/include/libcamera/internal/software_isp/debayer_params.h
+++ b/include/libcamera/internal/software_isp/debayer_params.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
- * Copyright (C) 2023, Red Hat Inc.
+ * Copyright (C) 2023, 2024 Red Hat Inc.
  *
  * Authors:
  * Hans de Goede <hdegoede@redhat.com>
@@ -10,20 +10,20 @@
 
 #pragma once
 
+#include <array>
+#include <stdint.h>
+
 namespace libcamera {
 
 struct DebayerParams {
 	static constexpr unsigned int kGain10 = 256;
+	static constexpr unsigned int kRGBLookupSize = 256;
 
-	unsigned int gainR;
-	unsigned int gainG;
-	unsigned int gainB;
+	using ColorLookupTable = std::array<uint8_t, kRGBLookupSize>;
 
-	float gamma;
-	/**
-	 * \brief Level of the black point, 0..255, 0 is no correction.
-	 */
-	unsigned int blackLevel;
+	ColorLookupTable red;
+	ColorLookupTable green;
+	ColorLookupTable blue;
 };
 
 } /* namespace libcamera */