ipa: rkisp1: ccm/lsc: Fix CCM/LSC based on manual color temperature

In RkISP1Awb::process(), the color temperature in the active state is
updated every time new statistics are available.  The CCM/LSC algorithms
use that value in prepare() to update the CCM/LSC. This is not correct
if the color temperature was specified manually and leads to visible
flicker even when AwbEnable is set to false.

To fix that, track the auto and manual color temperature separately in
active state. In Awb::prepare() the current frame context is updated
with the corresponding value from active state. Change the algorithms to
fetch the color temperature from the frame context instead of the active
state in prepare().

Fixes: 0230880954 ("ipa: rkisp1: awb: Implement ColourTemperature control")
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/ipa/rkisp1/algorithms/awb.cpp

@@ -130,7 +130,8 @@ int Awb::configure(IPAContext &context,
 	context.activeState.awb.automatic.gains =
 		awbAlgo_->gainsFromColourTemperature(kDefaultColourTemperature);
 	context.activeState.awb.autoEnabled = true;
-	context.activeState.awb.temperatureK = kDefaultColourTemperature;
+	context.activeState.awb.manual.temperatureK = kDefaultColourTemperature;
+	context.activeState.awb.automatic.temperatureK = kDefaultColourTemperature;
 
 	/*
 	 * Define the measurement window for AWB as a centered rectangle
@@ -187,7 +188,7 @@ void Awb::queueRequest(IPAContext &context,
 		const auto &gains = awbAlgo_->gainsFromColourTemperature(*colourTemperature);
 		awb.manual.gains.r() = gains.r();
 		awb.manual.gains.b() = gains.b();
-		awb.temperatureK = *colourTemperature;
+		awb.manual.temperatureK = *colourTemperature;
 		update = true;
 	}
 
@@ -196,7 +197,7 @@ void Awb::queueRequest(IPAContext &context,
 			<< "Set colour gains to " << awb.manual.gains;
 
 	frameContext.awb.gains = awb.manual.gains;
-	frameContext.awb.temperatureK = awb.temperatureK;
+	frameContext.awb.temperatureK = awb.manual.temperatureK;
 }
 
 /**
@@ -210,8 +211,9 @@ void Awb::prepare(IPAContext &context, const uint32_t frame,
 	 * most up-to-date automatic values we can read.
 	 */
 	if (frameContext.awb.autoEnabled) {
-		frameContext.awb.gains = context.activeState.awb.automatic.gains;
+		const auto &awb = context.activeState.awb;
-		frameContext.awb.temperatureK = context.activeState.awb.temperatureK;
+		frameContext.awb.gains = awb.automatic.gains;
+		frameContext.awb.temperatureK = awb.automatic.temperatureK;
 	}
 
 	auto gainConfig = params->block<BlockType::AwbGain>();
@@ -316,7 +318,7 @@ void Awb::process(IPAContext &context,
 	RkISP1AwbStats awbStats{ rgbMeans };
 	AwbResult awbResult = awbAlgo_->calculateAwb(awbStats, frameContext.lux.lux);
 
-	activeState.awb.temperatureK = awbResult.colourTemperature;
+	activeState.awb.automatic.temperatureK = awbResult.colourTemperature;
 
 	/*
 	 * Clamp the gain values to the hardware, which expresses gains as Q2.8
@@ -337,7 +339,7 @@ void Awb::process(IPAContext &context,
 		<< std::showpoint
 		<< "Means " << rgbMeans << ", gains "
 		<< activeState.awb.automatic.gains << ", temp "
-		<< activeState.awb.temperatureK << "K";
+		<< activeState.awb.automatic.temperatureK << "K";
 }
 
 RGB<double> Awb::calculateRgbMeans(const IPAFrameContext &frameContext, const rkisp1_cif_isp_awb_stat *awb) const

src/ipa/rkisp1/algorithms/ccm.cpp

@@ -88,7 +88,7 @@ void Ccm::setParameters(struct rkisp1_cif_isp_ctk_config &config,
 void Ccm::prepare(IPAContext &context, const uint32_t frame,
 		  IPAFrameContext &frameContext, RkISP1Params *params)
 {
-	uint32_t ct = context.activeState.awb.temperatureK;
+	uint32_t ct = frameContext.awb.temperatureK;
 
 	/*
 	 * \todo The colour temperature will likely be noisy, add filtering to

src/ipa/rkisp1/algorithms/lsc.cpp

@@ -404,12 +404,12 @@ void LensShadingCorrection::copyTable(rkisp1_cif_isp_lsc_config &config,
 /**
  * \copydoc libcamera::ipa::Algorithm::prepare
  */
-void LensShadingCorrection::prepare(IPAContext &context,
+void LensShadingCorrection::prepare([[maybe_unused]] IPAContext &context,
 				    [[maybe_unused]] const uint32_t frame,
-				    [[maybe_unused]] IPAFrameContext &frameContext,
+				    IPAFrameContext &frameContext,
 				    RkISP1Params *params)
 {
-	uint32_t ct = context.activeState.awb.temperatureK;
+	uint32_t ct = frameContext.awb.temperatureK;
 	if (std::abs(static_cast<int>(ct) - static_cast<int>(lastAppliedCt_)) <
 	    kColourTemperatureChangeThreshhold)
 		return;

src/ipa/rkisp1/ipa_context.cpp

@@ -197,15 +197,15 @@ namespace libcamera::ipa::rkisp1 {
  * \var IPAActiveState::awb::AwbState.gains
  * \brief White balance gains
  *
+ * \var IPAActiveState::awb::AwbState.temperatureK
+ * \brief Color temperature
+ *
  * \var IPAActiveState::awb.manual
  * \brief Manual regulation state (set through requests)
  *
  * \var IPAActiveState::awb.automatic
  * \brief Automatic regulation state (computed by the algorithm)
  *
- * \var IPAActiveState::awb.temperatureK
- * \brief Estimated color temperature
- *
  * \var IPAActiveState::awb.autoEnabled
  * \brief Whether the Auto White Balance algorithm is enabled
  */
@@ -349,7 +349,10 @@ namespace libcamera::ipa::rkisp1 {
  * \brief White balance gains
  *
  * \var IPAFrameContext::awb.temperatureK
- * \brief Estimated color temperature
+ * \brief Color temperature used for processing this frame
+ *
+ * This does not match the color temperature estimated for this frame as the
+ * measurements were taken on a previous frame.
  *
  * \var IPAFrameContext::awb.autoEnabled
  * \brief Whether the Auto White Balance algorithm is enabled

src/ipa/rkisp1/ipa_context.h

@@ -91,12 +91,12 @@ struct IPAActiveState {
 	struct {
 		struct AwbState {
 			RGB<double> gains;
+			unsigned int temperatureK;
 		};
 
 		AwbState manual;
 		AwbState automatic;
 
-		unsigned int temperatureK;
 		bool autoEnabled;
 	} awb;