[libcamera-devel] [PATCH 01/11] Fixes Bug 156, which breaks libcamera on Android < 12.

nicholas at rothemail.net nicholas at rothemail.net
Mon Oct 24 07:55:33 CEST 2022


From: Nicholas Roth <nicholas at rothemail.net>

---
 src/ipa/ipu3/algorithms/agc.cpp            | 18 ++++++++++++++----
 src/ipa/raspberrypi/cam_helper.cpp         |  9 ++++++---
 src/ipa/raspberrypi/cam_helper_imx296.cpp  |  5 ++++-
 src/ipa/raspberrypi/controller/rpi/agc.cpp | 18 ++++++++++++++----
 src/ipa/raspberrypi/controller/rpi/lux.cpp |  5 ++++-
 src/ipa/rkisp1/algorithms/agc.cpp          | 22 ++++++++++++++++++----
 6 files changed, 60 insertions(+), 17 deletions(-)

diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp
index a1a3c38f..80c551bb 100644
--- a/src/ipa/ipu3/algorithms/agc.cpp
+++ b/src/ipa/ipu3/algorithms/agc.cpp
@@ -100,7 +100,10 @@ int Agc::configure(IPAContext &context,
 
 	/* Configure the default exposure and gain. */
 	activeState.agc.gain = std::max(minAnalogueGain_, kMinAnalogueGain);
-	activeState.agc.exposure = 10ms / configuration.sensor.lineDuration;
+	/* TODO(Bug 156): Workaround for LLVM bug. */
+	double ten_millis = utils::Duration(10ms).get<std::nano>();
+	activeState.agc.exposure = ten_millis /
+		configuration.sensor.lineDuration.get<std::nano>();
 
 	frameCount_ = 0;
 	return 0;
@@ -238,11 +241,16 @@ void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext,
 	 *
 	 * Push the shutter time up to the maximum first, and only then
 	 * increase the gain.
+	 *
+	 * TODO(Bug 156): Workaround for LLVM bug.
 	 */
+	double exposureValueDouble = exposureValue.get<std::nano>();
+	utils::Duration shutterTimeRaw(exposureValueDouble / minAnalogueGain_);
 	utils::Duration shutterTime =
-		std::clamp<utils::Duration>(exposureValue / minAnalogueGain_,
+		std::clamp<utils::Duration>(shutterTimeRaw,
 					    minShutterSpeed_, maxShutterSpeed_);
-	double stepGain = std::clamp(exposureValue / shutterTime,
+	double shutterTimeDouble = shutterTime.get<std::nano>();
+	double stepGain = std::clamp(exposureValueDouble / shutterTimeDouble,
 				     minAnalogueGain_, maxAnalogueGain_);
 	LOG(IPU3Agc, Debug) << "Divided up shutter and gain are "
 			    << shutterTime << " and "
@@ -250,7 +258,9 @@ void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext,
 
 	IPAActiveState &activeState = context.activeState;
 	/* Update the estimated exposure and gain. */
-	activeState.agc.exposure = shutterTime / configuration.sensor.lineDuration;
+	/* TODO(Bug 156): Workaround for LLVM bug. */
+	double lineDurationDouble = configuration.sensor.lineDuration.get<std::nano>();
+	activeState.agc.exposure = shutterTimeDouble / lineDurationDouble;
 	activeState.agc.gain = stepGain;
 }
 
diff --git a/src/ipa/raspberrypi/cam_helper.cpp b/src/ipa/raspberrypi/cam_helper.cpp
index d90ac1de..31a9a1ef 100644
--- a/src/ipa/raspberrypi/cam_helper.cpp
+++ b/src/ipa/raspberrypi/cam_helper.cpp
@@ -63,7 +63,8 @@ void CamHelper::process([[maybe_unused]] StatisticsPtr &stats,
 
 uint32_t CamHelper::exposureLines(const Duration exposure, const Duration lineLength) const
 {
-	return exposure / lineLength;
+	/* TODO(Bug 156): Workaround for LLVM bug. */
+	return exposure.get<std::nano>() / lineLength.get<std::nano>();
 }
 
 Duration CamHelper::exposure(uint32_t exposureLines, const Duration lineLength) const
@@ -84,9 +85,11 @@ std::pair<uint32_t, uint32_t> CamHelper::getBlanking(Duration &exposure,
 	 *
 	 * frameLengthMax gets calculated on the smallest line length as we do
 	 * not want to extend that unless absolutely necessary.
+	 *
+	 * TODO(Bug 156): Workaround for LLVM bug.
 	 */
-	frameLengthMin = minFrameDuration / mode_.minLineLength;
-	frameLengthMax = maxFrameDuration / mode_.minLineLength;
+	frameLengthMin = minFrameDuration.get<std::nano>() / mode_.minLineLength.get<std::nano>();
+	frameLengthMax = maxFrameDuration.get<std::nano>() / mode_.minLineLength.get<std::nano>();
 
 	/*
 	 * Watch out for (exposureLines + frameIntegrationDiff_) overflowing a
diff --git a/src/ipa/raspberrypi/cam_helper_imx296.cpp b/src/ipa/raspberrypi/cam_helper_imx296.cpp
index ecb845e7..e48f5cf2 100644
--- a/src/ipa/raspberrypi/cam_helper_imx296.cpp
+++ b/src/ipa/raspberrypi/cam_helper_imx296.cpp
@@ -57,7 +57,10 @@ double CamHelperImx296::gain(uint32_t gainCode) const
 uint32_t CamHelperImx296::exposureLines(const Duration exposure,
 					[[maybe_unused]] const Duration lineLength) const
 {
-	return std::max<uint32_t>(minExposureLines, (exposure - 14.26us) / timePerLine);
+	/* TODO(Bug 156): Workaround for LLVM bug. */
+	double exposureTime = Duration(exposure - 14.26us).get<std::nano>();
+	double timePerLineNano = timePerLine.get<std::nano>();
+	return std::max<uint32_t>(minExposureLines, exposureTime / timePerLineNano);
 }
 
 Duration CamHelperImx296::exposure(uint32_t exposureLines,
diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp
index bd54a639..720ba788 100644
--- a/src/ipa/raspberrypi/controller/rpi/agc.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp
@@ -418,7 +418,10 @@ void Agc::prepare(Metadata *imageMetadata)
 			Duration actualExposure = deviceStatus.shutterSpeed *
 						  deviceStatus.analogueGain;
 			if (actualExposure) {
-				status_.digitalGain = status_.totalExposureValue / actualExposure;
+				/* TODO(Bug 156): Workaround for LLVM bug. */
+				double totalExposureDouble = status_.totalExposureValue.get<std::nano>();
+				double actualExposureDouble = actualExposure.get<std::nano>();
+				status_.digitalGain = totalExposureDouble / actualExposureDouble;
 				LOG(RPiAgc, Debug) << "Want total exposure " << status_.totalExposureValue;
 				/*
 				 * Never ask for a gain < 1.0, and also impose
@@ -823,7 +826,10 @@ void Agc::divideUpExposure()
 			}
 			if (status_.fixedAnalogueGain == 0.0) {
 				if (exposureMode_->gain[stage] * shutterTime >= exposureValue) {
-					analogueGain = exposureValue / shutterTime;
+					/* TODO(Bug 156): Workaround for LLVM bug. */
+					double exposureDouble = exposureValue.get<std::nano>();
+					double shutterTimeDouble = shutterTime.get<std::nano>();
+					analogueGain = exposureDouble / shutterTimeDouble;
 					break;
 				}
 				analogueGain = exposureMode_->gain[stage];
@@ -838,10 +844,14 @@ void Agc::divideUpExposure()
 	 */
 	if (!status_.fixedShutter && !status_.fixedAnalogueGain &&
 	    status_.flickerPeriod) {
-		int flickerPeriods = shutterTime / status_.flickerPeriod;
+		/* TODO(Bug 156): Workaround for LLVM bug. */
+		double shutterTimeDouble = shutterTime.get<std::nano>();
+		double flickerPeriod = status_.flickerPeriod.get<std::nano>();
+		int flickerPeriods = shutterTimeDouble / flickerPeriod;
 		if (flickerPeriods) {
 			Duration newShutterTime = flickerPeriods * status_.flickerPeriod;
-			analogueGain *= shutterTime / newShutterTime;
+			double newShutterTimeDouble = newShutterTime.get<std::nano>();
+			analogueGain *= shutterTimeDouble / newShutterTimeDouble;
 			/*
 			 * We should still not allow the ag to go over the
 			 * largest value in the exposure mode. Note that this
diff --git a/src/ipa/raspberrypi/controller/rpi/lux.cpp b/src/ipa/raspberrypi/controller/rpi/lux.cpp
index 9759186a..49303409 100644
--- a/src/ipa/raspberrypi/controller/rpi/lux.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/lux.cpp
@@ -93,8 +93,11 @@ void Lux::process(StatisticsPtr &stats, Metadata *imageMetadata)
 		/* add .5 to reflect the mid-points of bins */
 		double currentY = sum / (double)num + .5;
 		double gainRatio = referenceGain_ / currentGain;
+		/* TODO(Bug 156): Workaround for LLVM bug. */
+		double referenceShutterSpeedDouble = referenceShutterSpeed_.get<std::nano>();
+		double deviceShutterSpeed = deviceStatus.shutterSpeed.get<std::nano>();
 		double shutterSpeedRatio =
-			referenceShutterSpeed_ / deviceStatus.shutterSpeed;
+			referenceShutterSpeedDouble / deviceShutterSpeed;
 		double apertureRatio = referenceAperture_ / currentAperture;
 		double yRatio = currentY * (65536 / numBins) / referenceY_;
 		double estimatedLux = shutterSpeedRatio * gainRatio *
diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index 04062a36..3ea0b732 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -74,7 +74,13 @@ int Agc::configure(IPAContext &context, const IPACameraSensorInfo &configInfo)
 {
 	/* Configure the default exposure and gain. */
 	context.activeState.agc.gain = std::max(context.configuration.agc.minAnalogueGain, kMinAnalogueGain);
-	context.activeState.agc.exposure = 10ms / context.configuration.sensor.lineDuration;
+	/* TODO(Bug 156): Explicit division of ticks (e.g., `x.get<std::nano>() /
+	 * y.get<std::nano>()` as opposed to `x / y`) is a workaround for
+	 * LLVM bug 41130 and should be reverted once we no longer target
+	 * Android 11 / sdk30 since it compromises unit safety and readability. */
+	constexpr libcamera::utils::Duration ten_millis(10ms);
+	long double exposure = ten_millis.get<std::nano>() / context.configuration.sensor.lineDuration.get<std::nano>();
+	context.activeState.agc.exposure = uint32_t(exposure);
 
 	/*
 	 * According to the RkISP1 documentation:
@@ -211,17 +217,25 @@ void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext,
 	/*
 	 * Push the shutter time up to the maximum first, and only then
 	 * increase the gain.
+	 *
+	 * TODO(Bug 156): Explicit division of ticks (e.g., `x.get<std::nano>() /
+	 * y.get<std::nano>()` as opposed to `x / y`) is a workaround for
+	 * LLVM bug 41130 and should be reverted once we no longer target
+	 * Android 11 / sdk30 since it compromises unit safety and readability.
 	 */
-	utils::Duration shutterTime = std::clamp<utils::Duration>(exposureValue / minAnalogueGain,
+	utils::Duration shutterTimeUnclamped(exposureValue.get<std::nano>() / minAnalogueGain);
+	utils::Duration shutterTime = std::clamp<utils::Duration>(shutterTimeUnclamped,
 								  minShutterSpeed, maxShutterSpeed);
-	double stepGain = std::clamp(exposureValue / shutterTime,
+	double stepGainUnclamped = exposureValue.get<std::nano>() / shutterTime.get<std::nano>();
+	double stepGain = std::clamp(stepGainUnclamped,
 				     minAnalogueGain, maxAnalogueGain);
 	LOG(RkISP1Agc, Debug) << "Divided up shutter and gain are "
 			      << shutterTime << " and "
 			      << stepGain;
 
 	/* Update the estimated exposure and gain. */
-	activeState.agc.exposure = shutterTime / configuration.sensor.lineDuration;
+	activeState.agc.exposure = uint32_t(shutterTime.get<std::nano>() /
+		configuration.sensor.lineDuration.get<std::nano>());
 	activeState.agc.gain = stepGain;
 }
 
-- 
2.34.1



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