[PATCH 1/2] libcamera: software_isp: Initialize exposure+gain before agc calculations

[Stanislaw Gruszka]

On my setup, since commit fb8ad13d ("libcamera: software_isp: Move exposure+gain
to an algorithm module"), at start camera output stays very dark for dozen
of seconds, and then later slowly gets to normal. This is because existing
sensor exposure+gain settings are not used at start. We save initial
values in frameContext but in the agc algorithm we use IPA context.

Fix the problem by using in frameContext sensor values, since we already
use those in blc algorithm and change exposure type to int32_t to
unnecessary castings.

Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka at linux.intel.com>
---
 src/ipa/simple/algorithms/agc.cpp | 8 ++++----
 src/ipa/simple/algorithms/agc.h   | 2 +-
 src/ipa/simple/algorithms/blc.h   | 2 +-
 src/ipa/simple/ipa_context.h      | 2 +-
 src/ipa/simple/soft_simple.cpp    | 4 ++--
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/ipa/simple/algorithms/agc.cpp b/src/ipa/simple/algorithms/agc.cpp
index df92edd7..72aade14 100644
--- a/src/ipa/simple/algorithms/agc.cpp
+++ b/src/ipa/simple/algorithms/agc.cpp
@@ -39,7 +39,7 @@ Agc::Agc()
 {
 }
 
-void Agc::updateExposure(IPAContext &context, double exposureMSV)
+void Agc::updateExposure(IPAContext &context, IPAFrameContext &frameContext, double exposureMSV)
 {
 	/*
 	 * kExpDenominator of 10 gives ~10% increment/decrement;
@@ -50,8 +50,8 @@ void Agc::updateExposure(IPAContext &context, double exposureMSV)
 	static constexpr uint8_t kExpNumeratorDown = kExpDenominator - 1;
 
 	double next;
-	int32_t &exposure = context.activeState.agc.exposure;
-	double &again = context.activeState.agc.again;
+	int32_t &exposure = frameContext.sensor.exposure;
+	double &again = frameContext.sensor.gain;
 
 	if (exposureMSV < kExposureOptimal - kExposureSatisfactory) {
 		next = exposure * kExpNumeratorUp / kExpDenominator;
@@ -129,7 +129,7 @@ void Agc::process(IPAContext &context,
 	}
 
 	float exposureMSV = (denom == 0 ? 0 : static_cast<float>(num) / denom);
-	updateExposure(context, exposureMSV);
+	updateExposure(context, frameContext, exposureMSV);
 }
 
 REGISTER_IPA_ALGORITHM(Agc, "Agc")
diff --git a/src/ipa/simple/algorithms/agc.h b/src/ipa/simple/algorithms/agc.h
index ad5fca9f..112d9f5a 100644
--- a/src/ipa/simple/algorithms/agc.h
+++ b/src/ipa/simple/algorithms/agc.h
@@ -25,7 +25,7 @@ public:
 		     ControlList &metadata) override;
 
 private:
-	void updateExposure(IPAContext &context, double exposureMSV);
+	void updateExposure(IPAContext &context, IPAFrameContext &frameContext, double exposureMSV);
 };
 
 } /* namespace ipa::soft::algorithms */
diff --git a/src/ipa/simple/algorithms/blc.h b/src/ipa/simple/algorithms/blc.h
index 2cf2a877..67c688ae 100644
--- a/src/ipa/simple/algorithms/blc.h
+++ b/src/ipa/simple/algorithms/blc.h
@@ -27,7 +27,7 @@ public:
 		     ControlList &metadata) override;
 
 private:
-	uint32_t exposure_;
+	int32_t exposure_;
 	double gain_;
 };
 
diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h
index fd121eeb..c510c436 100644
--- a/src/ipa/simple/ipa_context.h
+++ b/src/ipa/simple/ipa_context.h
@@ -53,7 +53,7 @@ struct IPAActiveState {
 
 struct IPAFrameContext : public FrameContext {
 	struct {
-		uint32_t exposure;
+		int32_t exposure;
 		double gain;
 	} sensor;
 };
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
index c8ad55a2..dfacd6aa 100644
--- a/src/ipa/simple/soft_simple.cpp
+++ b/src/ipa/simple/soft_simple.cpp
@@ -310,8 +310,8 @@ void IPASoftSimple::processStats(const uint32_t frame,
 
 	ControlList ctrls(sensorInfoMap_);
 
-	auto &againNew = context_.activeState.agc.again;
-	ctrls.set(V4L2_CID_EXPOSURE, context_.activeState.agc.exposure);
+	auto &againNew = frameContext.sensor.gain;
+	ctrls.set(V4L2_CID_EXPOSURE, frameContext.sensor.exposure);
 	ctrls.set(V4L2_CID_ANALOGUE_GAIN,
 		  static_cast<int32_t>(camHelper_ ? camHelper_->gainCode(againNew) : againNew));
 
-- 
2.43.0