[v2,3/5] libcamera: software_isp: Move color mappings out of debayering
diff mbox series

Message ID 20240430173430.200392-4-mzamazal@redhat.com
State New
Headers show
Series
  • Software ISP levels cleanup
Related show

Commit Message

Milan Zamazal April 30, 2024, 5:34 p.m. UTC 
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.

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>
---
 .../internal/software_isp/debayer_params.h    | 18 +++----
 src/ipa/simple/soft_simple.cpp                | 51 +++++++++++++++----
 src/libcamera/software_isp/debayer.cpp        | 29 +++++------
 src/libcamera/software_isp/debayer_cpu.cpp    | 41 +++------------
 src/libcamera/software_isp/debayer_cpu.h      |  9 ++--
 src/libcamera/software_isp/software_isp.cpp   |  4 +-
 6 files changed, 75 insertions(+), 77 deletions(-)

Patch
diff mbox series 

diff --git a/include/libcamera/internal/software_isp/debayer_params.h b/include/libcamera/internal/software_isp/debayer_params.h
index 32cd448a..09f4ff00 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 */
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
index f595abc2..981e1ae0 100644
--- a/src/ipa/simple/soft_simple.cpp
+++ b/src/ipa/simple/soft_simple.cpp
@@ -5,6 +5,7 @@ 
  * soft_simple.cpp - Simple Software Image Processing Algorithm module
  */
 
+#include <math.h>
 #include <numeric>
 #include <stdint.h>
 #include <sys/mman.h>
@@ -84,6 +85,10 @@  private:
 	ControlInfoMap sensorInfoMap_;
 	BlackLevel blackLevel_;
 
+	static constexpr unsigned int kGammaLookupSize = 1024;
+	std::array<uint8_t, kGammaLookupSize> gammaTable_;
+	int lastBlackLevel_ = -1;
+
 	int32_t exposureMin_, exposureMax_;
 	int32_t exposure_;
 	double againMin_, againMax_, againMinStep_;
@@ -246,7 +251,6 @@  void IPASoftSimple::processStats(const ControlList &sensorControls)
 	if (ignoreUpdates_ > 0)
 		blackLevel_.update(histogram);
 	const uint8_t blackLevel = blackLevel_.get();
-	params_->blackLevel = blackLevel;
 
 	/*
 	 * Calculate red and blue gains for AWB.
@@ -265,12 +269,41 @@  void IPASoftSimple::processStats(const ControlList &sensorControls)
 	const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2);
 	const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4);
 
-	params_->gainR = sumR <= sumG / 4 ? 1024 : 256 * sumG / sumR;
-	params_->gainB = sumB <= sumG / 4 ? 1024 : 256 * sumG / sumB;
-
+	/* Gain: 128 = 0.5, 256 = 1.0, 512 = 2.0, etc. */
+	const unsigned int gainR = sumR <= sumG / 4 ? 1024 : 256 * sumG / sumR;
+	const unsigned int gainB = sumB <= sumG / 4 ? 1024 : 256 * sumG / sumB;
 	/* Green gain and gamma values are fixed */
-	params_->gainG = 256;
-	params_->gamma = 0.5;
+	constexpr unsigned int gainG = 256;
+	/* gamma == 1.0 means no correction */
+	constexpr float gamma = 0.5;
+
+	/* Update the gamma table if needed */
+	if (blackLevel != lastBlackLevel_) {
+		const unsigned int blackIndex = blackLevel * kGammaLookupSize / 256;
+		std::fill(gammaTable_.begin(), gammaTable_.begin() + blackIndex, 0);
+		const float divisor = kGammaLookupSize - blackIndex - 1.0;
+		for (unsigned int i = blackIndex; i < kGammaLookupSize; i++)
+			gammaTable_[i] = UINT8_MAX * powf((i - blackIndex) / divisor, gamma);
+
+		lastBlackLevel_ = blackLevel;
+	}
+
+	for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++) {
+		constexpr unsigned int div =
+			DebayerParams::kRGBLookupSize * DebayerParams::kGain10 /
+			kGammaLookupSize;
+		unsigned int idx;
+
+		/* Apply gamma after gain! */
+		idx = std::min({ i * gainR / div, (kGammaLookupSize - 1) });
+		params_->red[i] = gammaTable_[idx];
+
+		idx = std::min({ i * gainG / div, (kGammaLookupSize - 1) });
+		params_->green[i] = gammaTable_[idx];
+
+		idx = std::min({ i * gainB / div, (kGammaLookupSize - 1) });
+		params_->blue[i] = gammaTable_[idx];
+	}
 
 	setIspParams.emit();
 
@@ -291,7 +324,7 @@  void IPASoftSimple::processStats(const ControlList &sensorControls)
 	 * https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
 	 */
 	const unsigned int blackLevelHistIdx =
-		params_->blackLevel / (256 / SwIspStats::kYHistogramSize);
+		blackLevel / (256 / SwIspStats::kYHistogramSize);
 	const unsigned int histogramSize =
 		SwIspStats::kYHistogramSize - blackLevelHistIdx;
 	const unsigned int yHistValsPerBin = histogramSize / kExposureBinsCount;
@@ -339,8 +372,8 @@  void IPASoftSimple::processStats(const ControlList &sensorControls)
 
 	LOG(IPASoft, Debug) << "exposureMSV " << exposureMSV
 			    << " exp " << exposure_ << " again " << again_
-			    << " gain R/B " << params_->gainR << "/" << params_->gainB
-			    << " black level " << params_->blackLevel;
+			    << " gain R/B " << gainR << "/" << gainB
+			    << " black level " << blackLevel;
 }
 
 void IPASoftSimple::updateExposure(double exposureMSV)
diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp
index 1c035e9b..ac438a33 100644
--- a/src/libcamera/software_isp/debayer.cpp
+++ b/src/libcamera/software_isp/debayer.cpp
@@ -1,7 +1,7 @@ 
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2023, Linaro Ltd
- * Copyright (C) 2023, Red Hat Inc.
+ * Copyright (C) 2023, 2024 Red Hat Inc.
  *
  * Authors:
  * Hans de Goede <hdegoede@redhat.com>
@@ -24,29 +24,28 @@  namespace libcamera {
  */
 
 /**
- * \var DebayerParams::gainR
- * \brief Red gain
- *
- * 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ * \var DebayerParams::kRGBLookupSize
+ * \brief Size of a color lookup table
  */
 
 /**
- * \var DebayerParams::gainG
- * \brief Green gain
- *
- * 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ * \typedef DebayerParams::ColorLookupTable
+ * \brief Type of the lookup tables for red, green, blue values
  */
 
 /**
- * \var DebayerParams::gainB
- * \brief Blue gain
- *
- * 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ * \var DebayerParams::red
+ * \brief Lookup table for red color, mapping input values to output values
+ */
+
+/**
+ * \var DebayerParams::green
+ * \brief Lookup table for green color, mapping input values to output values
  */
 
 /**
- * \var DebayerParams::gamma
- * \brief Gamma correction, 1.0 is no correction
+ * \var DebayerParams::blue
+ * \brief Lookup table for blue color, mapping input values to output values
  */
 
 /**
diff --git a/src/libcamera/software_isp/debayer_cpu.cpp b/src/libcamera/software_isp/debayer_cpu.cpp
index 88d6578b..8b2b2f40 100644
--- a/src/libcamera/software_isp/debayer_cpu.cpp
+++ b/src/libcamera/software_isp/debayer_cpu.cpp
@@ -11,7 +11,6 @@ 
 
 #include "debayer_cpu.h"
 
-#include <math.h>
 #include <stdlib.h>
 #include <time.h>
 
@@ -47,9 +46,9 @@  DebayerCpu::DebayerCpu(std::unique_ptr<SwStatsCpu> stats)
 	 */
 	enableInputMemcpy_ = true;
 
-	/* Initialize gamma to 1.0 curve */
-	for (unsigned int i = 0; i < kGammaLookupSize; i++)
-		gamma_[i] = i / (kGammaLookupSize / kRGBLookupSize);
+	/* Initialize color lookup tables */
+	for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++)
+		red_[i] = green_[i] = blue_[i] = i;
 
 	for (unsigned int i = 0; i < kMaxLineBuffers; i++)
 		lineBuffers_[i] = nullptr;
@@ -698,37 +697,9 @@  void DebayerCpu::process(FrameBuffer *input, FrameBuffer *output, DebayerParams
 		clock_gettime(CLOCK_MONOTONIC_RAW, &frameStartTime);
 	}
 
-	/* Apply DebayerParams */
-	if (params.gamma != gammaCorrection_ || params.blackLevel != blackLevel_) {
-		const unsigned int blackIndex =
-			params.blackLevel * kGammaLookupSize / 256;
-		std::fill(gamma_.begin(), gamma_.begin() + blackIndex, 0);
-		const float divisor = kGammaLookupSize - blackIndex - 1.0;
-		for (unsigned int i = blackIndex; i < kGammaLookupSize; i++)
-			gamma_[i] = UINT8_MAX * powf((i - blackIndex) / divisor, params.gamma);
-
-		gammaCorrection_ = params.gamma;
-		blackLevel_ = params.blackLevel;
-	}
-
-	if (swapRedBlueGains_)
-		std::swap(params.gainR, params.gainB);
-
-	for (unsigned int i = 0; i < kRGBLookupSize; i++) {
-		constexpr unsigned int div =
-			kRGBLookupSize * DebayerParams::kGain10 / kGammaLookupSize;
-		unsigned int idx;
-
-		/* Apply gamma after gain! */
-		idx = std::min({ i * params.gainR / div, (kGammaLookupSize - 1) });
-		red_[i] = gamma_[idx];
-
-		idx = std::min({ i * params.gainG / div, (kGammaLookupSize - 1) });
-		green_[i] = gamma_[idx];
-
-		idx = std::min({ i * params.gainB / div, (kGammaLookupSize - 1) });
-		blue_[i] = gamma_[idx];
-	}
+	green_ = params.green;
+	red_ = swapRedBlueGains_ ? params.blue : params.red;
+	blue_ = swapRedBlueGains_ ? params.red : params.blue;
 
 	/* Copy metadata from the input buffer */
 	FrameMetadata &metadata = output->_d()->metadata();
diff --git a/src/libcamera/software_isp/debayer_cpu.h b/src/libcamera/software_isp/debayer_cpu.h
index 689c1075..47373426 100644
--- a/src/libcamera/software_isp/debayer_cpu.h
+++ b/src/libcamera/software_isp/debayer_cpu.h
@@ -122,15 +122,12 @@  private:
 	void process2(const uint8_t *src, uint8_t *dst);
 	void process4(const uint8_t *src, uint8_t *dst);
 
-	static constexpr unsigned int kGammaLookupSize = 1024;
-	static constexpr unsigned int kRGBLookupSize = 256;
 	/* Max. supported Bayer pattern height is 4, debayering this requires 5 lines */
 	static constexpr unsigned int kMaxLineBuffers = 5;
 
-	std::array<uint8_t, kGammaLookupSize> gamma_;
-	std::array<uint8_t, kRGBLookupSize> red_;
-	std::array<uint8_t, kRGBLookupSize> green_;
-	std::array<uint8_t, kRGBLookupSize> blue_;
+	DebayerParams::ColorLookupTable red_;
+	DebayerParams::ColorLookupTable green_;
+	DebayerParams::ColorLookupTable blue_;
 	debayerFn debayer0_;
 	debayerFn debayer1_;
 	debayerFn debayer2_;
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index e4e56086..3e07453d 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -63,9 +63,7 @@  LOG_DEFINE_CATEGORY(SoftwareIsp)
  * handler
  */
 SoftwareIsp::SoftwareIsp(PipelineHandler *pipe, const CameraSensor *sensor)
-	: debayerParams_{ DebayerParams::kGain10, DebayerParams::kGain10,
-			  DebayerParams::kGain10, 0.5f, 0 },
-	  dmaHeap_(DmaHeap::DmaHeapFlag::Cma | DmaHeap::DmaHeapFlag::System)
+	: dmaHeap_(DmaHeap::DmaHeapFlag::Cma | DmaHeap::DmaHeapFlag::System)
 {
 	if (!dmaHeap_.isValid()) {
 		LOG(SoftwareIsp, Error) << "Failed to create DmaHeap object";