From afa8cbca9eef3028136ca742ccd510a29570e97b Mon Sep 17 00:00:00 2001
From: Stefan Klug <stefan.klug@ideasonboard.com>
Date: Wed, 3 Jul 2024 15:49:52 +0200
Subject: ipa: rkisp1: blc: Report sensor black levels in metadata

Add sensor black levels to the metadata of the rkisp1 pipeline.

Additionally enable raw support for this algorithm and add it to
uncalibrated.yaml, so that black levels get reported when capturing
tuning images. This is a bit of a hack, because no actual black level
correction is taking place in raw mode, but it is the easiest way to get
blacklevel reported for raw streams.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/ipa/rkisp1/algorithms/blc.cpp     | 28 ++++++++++++++++++++++++++++
 src/ipa/rkisp1/algorithms/blc.h       |  5 ++++-
 src/ipa/rkisp1/data/uncalibrated.yaml |  1 +
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/ipa/rkisp1/algorithms/blc.cpp b/src/ipa/rkisp1/algorithms/blc.cpp
index b17b549c..03ec57f2 100644
--- a/src/ipa/rkisp1/algorithms/blc.cpp
+++ b/src/ipa/rkisp1/algorithms/blc.cpp
@@ -9,6 +9,8 @@
 
 #include <libcamera/base/log.h>
 
+#include <libcamera/control_ids.h>
+
 #include "libcamera/internal/yaml_parser.h"
 
 /**
@@ -38,6 +40,13 @@ LOG_DEFINE_CATEGORY(RkISP1Blc)
 BlackLevelCorrection::BlackLevelCorrection()
 	: tuningParameters_(false)
 {
+	/*
+	 * This is a bit of a hack. In raw mode no black level correction
+	 * happens. This flag is used to ensure the metadata gets populated with
+	 * the black level which is needed to capture proper raw images for
+	 * tuning.
+	 */
+	supportsRaw_ = true;
 }
 
 /**
@@ -107,6 +116,9 @@ void BlackLevelCorrection::prepare([[maybe_unused]] IPAContext &context,
 				   [[maybe_unused]] IPAFrameContext &frameContext,
 				   rkisp1_params_cfg *params)
 {
+	if (context.configuration.raw)
+		return;
+
 	if (frame > 0)
 		return;
 
@@ -125,6 +137,22 @@ void BlackLevelCorrection::prepare([[maybe_unused]] IPAContext &context,
 	params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_BLS;
 }
 
+/**
+ * \copydoc libcamera::ipa::Algorithm::process
+ */
+void BlackLevelCorrection::process([[maybe_unused]] IPAContext &context,
+				   [[maybe_unused]] const uint32_t frame,
+				   [[maybe_unused]] IPAFrameContext &frameContext,
+				   [[maybe_unused]] const rkisp1_stat_buffer *stats,
+				   ControlList &metadata)
+{
+	metadata.set(controls::SensorBlackLevels,
+		     { static_cast<int32_t>(blackLevelRed_),
+		       static_cast<int32_t>(blackLevelGreenR_),
+		       static_cast<int32_t>(blackLevelGreenB_),
+		       static_cast<int32_t>(blackLevelBlue_) });
+}
+
 REGISTER_IPA_ALGORITHM(BlackLevelCorrection, "BlackLevelCorrection")
 
 } /* namespace ipa::rkisp1::algorithms */
diff --git a/src/ipa/rkisp1/algorithms/blc.h b/src/ipa/rkisp1/algorithms/blc.h
index 460ebcc1..4ecac233 100644
--- a/src/ipa/rkisp1/algorithms/blc.h
+++ b/src/ipa/rkisp1/algorithms/blc.h
@@ -23,7 +23,10 @@ public:
 	void prepare(IPAContext &context, const uint32_t frame,
 		     IPAFrameContext &frameContext,
 		     rkisp1_params_cfg *params) override;
-
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const rkisp1_stat_buffer *stats,
+		     ControlList &metadata) override;
 private:
 	bool tuningParameters_;
 	int16_t blackLevelRed_;
diff --git a/src/ipa/rkisp1/data/uncalibrated.yaml b/src/ipa/rkisp1/data/uncalibrated.yaml
index a7bbd8d8..60901296 100644
--- a/src/ipa/rkisp1/data/uncalibrated.yaml
+++ b/src/ipa/rkisp1/data/uncalibrated.yaml
@@ -5,4 +5,5 @@ version: 1
 algorithms:
   - Agc:
   - Awb:
+  - BlackLevelCorrection:
 ...
-- 
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