[RFC,v2,16/43] ipa: libipa: agc_mean_luminance: calculateNewEv(): Collect results

27465 diff mbox series

diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp
index ac5b6e7513..e74db62960 100644
--- a/src/ipa/ipu3/algorithms/agc.cpp
+++ b/src/ipa/ipu3/algorithms/agc.cpp
@@ -237,9 +237,7 @@  void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 	double analogueGain = frameContext.sensor.gain;
 	utils::Duration effectiveExposureValue = exposureTime * analogueGain;
 
-	utils::Duration newExposureTime;
-	double aGain, qGain, dGain;
-	std::tie(newExposureTime, aGain, qGain, dGain) = agc_.calculateNewEv({
+	const auto &newEv = agc_.calculateNewEv({
 		.traits = AgcTraits{
 			rgbTriples_,
 			{{
@@ -257,12 +255,12 @@  void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 
 	LOG(IPU3Agc, Debug)
 		<< "Divided up exposure time, analogue gain and digital gain are "
-		<< newExposureTime << ", " << aGain << " and " << dGain;
+		<< newEv.exposureTime << ", " << newEv.analogueGain << " and " << newEv.digitalGain;
 
 	IPAActiveState &activeState = context.activeState;
 	/* Update the estimated exposure time and gain. */
-	activeState.agc.exposure = newExposureTime / context.configuration.sensor.lineDuration;
-	activeState.agc.gain = aGain;
+	activeState.agc.exposure = newEv.exposureTime / context.configuration.sensor.lineDuration;
+	activeState.agc.gain = newEv.analogueGain;
 
 	metadata.set(controls::AnalogueGain, frameContext.sensor.gain);
 	metadata.set(controls::ExposureTime, exposureTime.get<std::micro>());
diff --git a/src/ipa/libipa/agc_mean_luminance.cpp b/src/ipa/libipa/agc_mean_luminance.cpp
index e8679c66be..5e12c4b475 100644
--- a/src/ipa/libipa/agc_mean_luminance.cpp
+++ b/src/ipa/libipa/agc_mean_luminance.cpp
@@ -668,6 +668,11 @@  utils::Duration AgcMeanLuminance::filterExposure(utils::Duration exposureValue)
  * \brief The index of the exposure mode to use
  */
 
+/**
+ * \struct AgcMeanLuminance::Result
+ * \brief Collection of results of the mean luminance AGC algorithm
+ */
+
 /**
  * \brief Calculate the new exposure value and split it between exposure time
  * and gain
@@ -680,7 +685,7 @@  utils::Duration AgcMeanLuminance::filterExposure(utils::Duration exposureValue)
  * \return Tuple of exposure time, analogue gain, quantization gain and digital
  * gain
  */
-std::tuple<utils::Duration, double, double, double>
+AgcMeanLuminance::Result
 AgcMeanLuminance::calculateNewEv(const Params &params)
 {
 	/*
@@ -699,7 +704,7 @@  AgcMeanLuminance::calculateNewEv(const Params &params)
 		 * doesn't get stuck with 0 in case the sensor driver allows a
 		 * min exposure of 0.
 		 */
-		return exposureModeHelper.splitExposure(10ms);
+		return { exposureModeHelper.splitExposure(10ms) };
 	}
 
 	double gain = estimateInitialGain(params.traits);
@@ -721,7 +726,7 @@  AgcMeanLuminance::calculateNewEv(const Params &params)
 	newExposureValue = filterExposure(newExposureValue);
 
 	frameCount_++;
-	return exposureModeHelper.splitExposure(newExposureValue);
+	return { exposureModeHelper.splitExposure(newExposureValue) };
 }
 
 /**
diff --git a/src/ipa/libipa/agc_mean_luminance.h b/src/ipa/libipa/agc_mean_luminance.h
index 9b82d97ab6..aa4c0369ac 100644
--- a/src/ipa/libipa/agc_mean_luminance.h
+++ b/src/ipa/libipa/agc_mean_luminance.h
@@ -9,7 +9,6 @@ 
 
 #include <map>
 #include <memory>
-#include <tuple>
 #include <vector>
 
 #include <libcamera/base/utils.h>
@@ -87,8 +86,10 @@  public:
 		uint32_t exposureModeIndex;
 	};
 
-	std::tuple<utils::Duration, double, double, double>
-	calculateNewEv(const Params &params);
+	struct Result : ExposureModeHelper::Result {
+	};
+
+	[[nodiscard]] Result calculateNewEv(const Params &params);
 
 	double effectiveYTarget() const;
 
diff --git a/src/ipa/libipa/exposure_mode_helper.cpp b/src/ipa/libipa/exposure_mode_helper.cpp
index 01c5cba8e2..762e27b4fd 100644
--- a/src/ipa/libipa/exposure_mode_helper.cpp
+++ b/src/ipa/libipa/exposure_mode_helper.cpp
@@ -153,6 +153,23 @@  double ExposureModeHelper::clampGain(double gain, double *quantizationGain) cons
 	return clamped;
 }
 
+/**
+ * \struct ExposureModeHelper::Result
+ * \brief Result of splitExposure()
+ *
+ * \var ExposureModeHelper::Result::exposureTime
+ * \brief The applicable exposure time
+ *
+ * \var ExposureModeHelper::Result::analogueGain
+ * \brief The applicable analogue gain
+ *
+ * \var ExposureModeHelper::Result::quantizationGain
+ * \brief The applicable quantization gain
+ *
+ * \var ExposureModeHelper::Result::digitalGain
+ * \brief The applicable digital gain
+ */
+
 /**
  * \brief Split exposure into exposure time and gain
  * \param[in] exposure Exposure value
@@ -190,7 +207,7 @@  double ExposureModeHelper::clampGain(double gain, double *quantizationGain) cons
  * \return Tuple of exposure time, analogue gain, quantization gain and digital
  * gain
  */
-std::tuple<utils::Duration, double, double, double>
+ExposureModeHelper::Result
 ExposureModeHelper::splitExposure(utils::Duration exposure) const
 {
 	ASSERT(maxExposureTime_);
diff --git a/src/ipa/libipa/exposure_mode_helper.h b/src/ipa/libipa/exposure_mode_helper.h
index 968192ddc5..2bab20f974 100644
--- a/src/ipa/libipa/exposure_mode_helper.h
+++ b/src/ipa/libipa/exposure_mode_helper.h
@@ -7,7 +7,6 @@ 
 
 #pragma once
 
-#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -30,8 +29,14 @@  public:
 	void setLimits(utils::Duration minExposureTime, utils::Duration maxExposureTime,
 		       double minGain, double maxGain);
 
-	std::tuple<utils::Duration, double, double, double>
-	splitExposure(utils::Duration exposure) const;
+	struct Result {
+		utils::Duration exposureTime;
+		double analogueGain;
+		double quantizationGain;
+		double digitalGain;
+	};
+
+	[[nodiscard]] Result splitExposure(utils::Duration exposure) const;
 
 	utils::Duration minExposureTime() const { return minExposureTime_; }
 	utils::Duration maxExposureTime() const { return maxExposureTime_; }
diff --git a/src/ipa/mali-c55/algorithms/agc.cpp b/src/ipa/mali-c55/algorithms/agc.cpp
index fb97b87c6e..821f43e9fd 100644
--- a/src/ipa/mali-c55/algorithms/agc.cpp
+++ b/src/ipa/mali-c55/algorithms/agc.cpp
@@ -332,9 +332,7 @@  void Agc::process(IPAContext &context,
 	utils::Duration currentShutter = exposure * configuration.sensor.lineDuration;
 	utils::Duration effectiveExposureValue = currentShutter * analogueGain;
 
-	utils::Duration shutterTime;
-	double aGain, qGain, dGain;
-	std::tie(shutterTime, aGain, qGain, dGain) = agc_.calculateNewEv({
+	const auto &newEv = agc_.calculateNewEv({
 		.traits = AgcTraits(statistics_),
 		.yHist = statistics_.yHist,
 		.effectiveExposureValue = effectiveExposureValue,
@@ -344,10 +342,10 @@  void Agc::process(IPAContext &context,
 
 	LOG(MaliC55Agc, Debug)
 		<< "Divided up shutter, analogue gain and digital gain are "
-		<< shutterTime << ", " << aGain << " and " << dGain;
+		<< newEv.exposureTime << ", " << newEv.analogueGain << " and " << newEv.digitalGain;
 
-	activeState.agc.automatic.exposure = shutterTime / configuration.sensor.lineDuration;
-	activeState.agc.automatic.sensorGain = aGain;
+	activeState.agc.automatic.exposure = newEv.exposureTime / configuration.sensor.lineDuration;
+	activeState.agc.automatic.sensorGain = newEv.analogueGain;
 
 	metadata.set(controls::ExposureTime, currentShutter.get<std::micro>());
 	metadata.set(controls::AnalogueGain, frameContext.agc.sensorGain);
diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index 8b4bcbd71b..a4567c8258 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -720,9 +720,7 @@  void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 	agc_.setExposureCompensation(pow(2.0, frameContext.agc.exposureValue));
 	agc_.setLux(frameContext.lux.lux);
 
-	utils::Duration newExposureTime;
-	double aGain, qGain, dGain;
-	std::tie(newExposureTime, aGain, qGain, dGain) = agc_.calculateNewEv({
+	const auto &newEv = agc_.calculateNewEv({
 		.traits = AgcTraits{
 			{ params->ae.exp_mean, context.hw.numAeCells },
 			meteringModes_.at(frameContext.agc.meteringMode),
@@ -735,21 +733,21 @@  void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 
 	LOG(RkISP1Agc, Debug)
 		<< "Divided up exposure time, analogue gain, quantization gain"
-		<< " and digital gain are " << newExposureTime << ", " << aGain
-		<< ", " << qGain << " and " << dGain;
+		<< " and digital gain are " << newEv.exposureTime << ", " << newEv.analogueGain
+		<< ", " << newEv.quantizationGain << " and " << newEv.digitalGain;
 
 	IPAActiveState &activeState = context.activeState;
 	/* Update the estimated exposure and gain. */
-	activeState.agc.automatic.exposure = newExposureTime / lineDuration;
-	activeState.agc.automatic.gain = aGain;
-	activeState.agc.automatic.quantizationGain = qGain;
+	activeState.agc.automatic.exposure = newEv.exposureTime / lineDuration;
+	activeState.agc.automatic.gain = newEv.analogueGain;
+	activeState.agc.automatic.quantizationGain = newEv.quantizationGain;
 	activeState.agc.automatic.yTarget = agc_.effectiveYTarget();
 	/*
 	 * Expand the target frame duration so that we do not run faster than
 	 * the minimum frame duration when we have short exposures.
 	 */
 	processFrameDuration(context, frameContext,
-			     std::max(frameContext.agc.minFrameDuration, newExposureTime));
+			     std::max(frameContext.agc.minFrameDuration, newEv.exposureTime));
 
 	fillMetadata(context, frameContext, metadata);
 }