[6/9] libcamera: software_isp: Add CCM algorithm
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Message ID 20241120180104.1221846-7-mzamazal@redhat.com
State New
Headers show
Series
  • Software ISP support for CCM
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Commit Message

Milan Zamazal Nov. 20, 2024, 6:01 p.m. UTC
This patch adds color correction matrix (CCM) algorithm to software ISP.
It is based on the corresponding algorithm in rkisp1.

The primary difference against hardware pipelines is that applying the
CCM is optional.  Applying CCM causes a significant slowdown, time
needed to process a frame raises by 40-90% on tested platforms.  If CCM
is really needed, it can be applied, if not, it's better to stick
without it.  This can be configured by presence or omission of Ccm
algorithm in the tuning file.

CCM is changed only if the determined temperature changes by at least
100 K (an arbitrarily selected value), to avoid recomputing the matrices
and lookup tables all the time.  Some ugly unsigned->signed int
typecasting is needed to compare the temperatures.

The outputs of the algorithm are not used yet, they will be enabled in
followup patches.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
---
 src/ipa/simple/algorithms/ccm.cpp     | 88 +++++++++++++++++++++++++++
 src/ipa/simple/algorithms/ccm.h       | 44 ++++++++++++++
 src/ipa/simple/algorithms/meson.build |  1 +
 src/ipa/simple/ipa_context.h          | 11 ++++
 4 files changed, 144 insertions(+)
 create mode 100644 src/ipa/simple/algorithms/ccm.cpp
 create mode 100644 src/ipa/simple/algorithms/ccm.h

Patch
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diff --git a/src/ipa/simple/algorithms/ccm.cpp b/src/ipa/simple/algorithms/ccm.cpp
new file mode 100644
index 000000000..bd2c03fe4
--- /dev/null
+++ b/src/ipa/simple/algorithms/ccm.cpp
@@ -0,0 +1,88 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Color correction matrix
+ */
+
+#include "ccm.h"
+
+#include <stdlib.h>
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/control_ids.h>
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+LOG_DEFINE_CATEGORY(IPASoftCcm)
+
+unsigned int Ccm::kTemperatureThreshold = 100;
+
+int Ccm::init([[maybe_unused]] IPAContext &context, const YamlObject &tuningData)
+{
+	int ret = ccm_.readYaml(tuningData["ccms"], "ct", "ccm");
+	if (ret < 0) {
+		LOG(IPASoftCcm, Warning)
+			<< "Failed to parse 'ccm' "
+			<< "parameter from tuning file; falling back to unit matrix";
+		ccmEnabled_ = false;
+	} else {
+		ccmEnabled_ = true;
+	}
+
+	return 0;
+}
+
+void Ccm::prepare(IPAContext &context, const uint32_t frame,
+		  IPAFrameContext &frameContext, [[maybe_unused]] DebayerParams *params)
+{
+	context.activeState.ccm.enabled = ccmEnabled_;
+
+	if (!ccmEnabled_)
+		return;
+
+	unsigned int ct = context.activeState.awb.temperatureK;
+
+	/* Change CCM only on bigger temperature changes. */
+	if (frame > 0 &&
+	    abs(static_cast<int>(ct) - static_cast<int>(ct_)) <
+		    static_cast<int>(kTemperatureThreshold)) {
+		frameContext.ccm.ccm = context.activeState.ccm.ccm;
+		context.activeState.ccm.changed = false;
+		return;
+	}
+
+	ct_ = ct;
+	Matrix<float, 3, 3> ccm = ccm_.getInterpolated(ct);
+
+	context.activeState.ccm.ccm = ccm;
+	frameContext.ccm.ccm = ccm;
+	context.activeState.ccm.changed = true;
+}
+
+void Ccm::process([[maybe_unused]] IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  [[maybe_unused]] const SwIspStats *stats,
+		  ControlList &metadata)
+{
+	if (!ccmEnabled_)
+		return;
+
+	float m[9];
+	for (unsigned int i = 0; i < 3; i++) {
+		for (unsigned int j = 0; j < 3; j++)
+			m[i * 3 + j] = frameContext.ccm.ccm[i][j];
+	}
+	metadata.set(controls::ColourCorrectionMatrix, m);
+}
+
+REGISTER_IPA_ALGORITHM(Ccm, "Ccm")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/ccm.h b/src/ipa/simple/algorithms/ccm.h
new file mode 100644
index 000000000..6b7efbe21
--- /dev/null
+++ b/src/ipa/simple/algorithms/ccm.h
@@ -0,0 +1,44 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Color correction matrix
+ */
+
+#pragma once
+
+#include "libipa/interpolator.h"
+#include "libipa/matrix.h"
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class Ccm : public Algorithm
+{
+public:
+	Ccm() = default;
+	~Ccm() = default;
+
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	void prepare(IPAContext &context,
+		     const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     DebayerParams *params) override;
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const SwIspStats *stats,
+		     ControlList &metadata) override;
+
+private:
+	static unsigned int kTemperatureThreshold;
+	unsigned int ct_;
+	bool ccmEnabled_;
+	Interpolator<Matrix<float, 3, 3>> ccm_;
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/meson.build b/src/ipa/simple/algorithms/meson.build
index 37a2eb534..2d0adb059 100644
--- a/src/ipa/simple/algorithms/meson.build
+++ b/src/ipa/simple/algorithms/meson.build
@@ -4,5 +4,6 @@  soft_simple_ipa_algorithms = files([
     'awb.cpp',
     'agc.cpp',
     'blc.cpp',
+    'ccm.cpp',
     'lut.cpp',
 ])
diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h
index 268ba9cec..5f9ec0afc 100644
--- a/src/ipa/simple/ipa_context.h
+++ b/src/ipa/simple/ipa_context.h
@@ -12,6 +12,7 @@ 
 #include <stdint.h>
 
 #include <libipa/fc_queue.h>
+#include <libipa/matrix.h>
 
 namespace libcamera {
 
@@ -52,9 +53,19 @@  struct IPAActiveState {
 		std::array<double, kGammaLookupSize> gammaTable;
 		uint8_t blackLevel;
 	} gamma;
+
+	struct {
+		Matrix<float, 3, 3> ccm;
+		bool enabled;
+		bool changed;
+	} ccm;
 };
 
 struct IPAFrameContext : public FrameContext {
+	struct {
+		Matrix<float, 3, 3> ccm;
+	} ccm;
+
 	struct {
 		uint32_t exposure;
 		double gain;