ipa: rkisp1: awb: Store per-frame information in frame context

Rework the algorithm's usage of the active state and frame context to
store data in the right place.

The active state stores two distinct categories of information:

- The consolidated value of all algorithm controls. Requests passed to
  the queueRequest() function store values for controls that the
  application wants to modify for that particular frame, and the
  queueRequest() function updates the active state with those values.
  The active state thus contains a consolidated view of the value of all
  controls handled by the algorithm.

- The value of parameters computed by the algorithm when running in auto
  mode. Algorithms running in auto mode compute new parameters every
  time statistics buffers are received (either synchronously, or
  possibly in a background thread). The latest computed value of those
  parameters is stored in the active state in the process() function.

The frame context also stores two categories of information:

- The value of the controls to be applied to the frame. These values are
  typically set in the queueRequest() function, from the consolidated
  control values stored in the active state. The frame context thus
  stores values for all controls related to the algorithm, not limited
  to the controls specified in the corresponding request, but
  consolidated from all requests that have been queued so far.

  For controls that can be specified manually or computed by the
  algorithm depending on the operation mode (such as the colour gains),
  the control value will be stored in the frame context in
  queueRequest() only when operating in manual mode. When operating in
  auto mode, the values are computed by the algorithm and stored in the
  frame context in prepare(), just before being stored in the ISP
  parameters buffer.

  The queueRequest() function can also store ancillary data in the frame
  context, such as flags to indicate if (and what) control values have
  changed compared to the previous request.

- Status information computed by the algorithm for a frame. For
  instance, the colour temperature estimated by the algorithm from ISP
  statistics calculated on a frame is stored in the frame context for
  that frame in the process() function.

The active state and frame context thus both contain identical members
for most control values, but store values that have a different meaning.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/ipa/rkisp1/algorithms/awb.cpp

@@ -36,9 +36,12 @@ LOG_DEFINE_CATEGORY(RkISP1Awb)
 int Awb::configure(IPAContext &context,
 		   const IPACameraSensorInfo &configInfo)
 {
-	context.activeState.awb.gains.red = 1.0;
+	context.activeState.awb.gains.manual.red = 1.0;
-	context.activeState.awb.gains.blue = 1.0;
+	context.activeState.awb.gains.manual.blue = 1.0;
-	context.activeState.awb.gains.green = 1.0;
+	context.activeState.awb.gains.manual.green = 1.0;
+	context.activeState.awb.gains.automatic.red = 1.0;
+	context.activeState.awb.gains.automatic.blue = 1.0;
+	context.activeState.awb.gains.automatic.green = 1.0;
 	context.activeState.awb.autoEnabled = true;
 
 	/*
@@ -75,13 +78,22 @@ uint32_t Awb::estimateCCT(double red, double green, double blue)
  * \copydoc libcamera::ipa::Algorithm::prepare
  */
 void Awb::prepare(IPAContext &context, const uint32_t frame,
-		  [[maybe_unused]] IPAFrameContext &frameContext,
+		  IPAFrameContext &frameContext, rkisp1_params_cfg *params)
-		  rkisp1_params_cfg *params)
 {
-	params->others.awb_gain_config.gain_green_b = 256 * context.activeState.awb.gains.green;
+	/*
-	params->others.awb_gain_config.gain_blue = 256 * context.activeState.awb.gains.blue;
+	 * This is the latest time we can read the active state. This is the
-	params->others.awb_gain_config.gain_red = 256 * context.activeState.awb.gains.red;
+	 * most up-to-date automatic values we can read.
-	params->others.awb_gain_config.gain_green_r = 256 * context.activeState.awb.gains.green;
+	 */
+	if (frameContext.awb.autoEnabled) {
+		frameContext.awb.gains.red = context.activeState.awb.gains.automatic.red;
+		frameContext.awb.gains.green = context.activeState.awb.gains.automatic.green;
+		frameContext.awb.gains.blue = context.activeState.awb.gains.automatic.blue;
+	}
+
+	params->others.awb_gain_config.gain_green_b = 256 * frameContext.awb.gains.green;
+	params->others.awb_gain_config.gain_blue = 256 * frameContext.awb.gains.blue;
+	params->others.awb_gain_config.gain_red = 256 * frameContext.awb.gains.red;
+	params->others.awb_gain_config.gain_green_r = 256 * frameContext.awb.gains.green;
 
 	/* Update the gains. */
 	params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_AWB_GAIN;
@@ -127,7 +139,7 @@ void Awb::prepare(IPAContext &context, const uint32_t frame,
  */
 void Awb::queueRequest(IPAContext &context,
 		       [[maybe_unused]] const uint32_t frame,
-		       [[maybe_unused]] IPAFrameContext &frameContext,
+		       IPAFrameContext &frameContext,
 		       const ControlList &controls)
 {
 	auto &awb = context.activeState.awb;
@@ -142,21 +154,29 @@ void Awb::queueRequest(IPAContext &context,
 
 	const auto &colourGains = controls.get(controls::ColourGains);
 	if (colourGains && !awb.autoEnabled) {
-		awb.gains.red = (*colourGains)[0];
+		awb.gains.manual.red = (*colourGains)[0];
-		awb.gains.blue = (*colourGains)[1];
+		awb.gains.manual.blue = (*colourGains)[1];
 
 		LOG(RkISP1Awb, Debug)
-			<< "Set colour gains to red: " << awb.gains.red
+			<< "Set colour gains to red: " << awb.gains.manual.red
-			<< ", blue: " << awb.gains.blue;
+			<< ", blue: " << awb.gains.manual.blue;
+	}
+
+	frameContext.awb.autoEnabled = awb.autoEnabled;
+
+	if (!awb.autoEnabled) {
+		frameContext.awb.gains.red = awb.gains.manual.red;
+		frameContext.awb.gains.green = 1.0;
+		frameContext.awb.gains.blue = awb.gains.manual.blue;
 	}
 }
 
 /**
  * \copydoc libcamera::ipa::Algorithm::process
  */
-void Awb::process([[maybe_unused]] IPAContext &context,
+void Awb::process(IPAContext &context,
 		  [[maybe_unused]] const uint32_t frame,
-		  [[maybe_unused]] IPAFrameContext &frameCtx,
+		  IPAFrameContext &frameContext,
 		  const rkisp1_stat_buffer *stats)
 {
 	const rkisp1_cif_isp_stat *params = &stats->params;
@@ -187,30 +207,27 @@ void Awb::process([[maybe_unused]] IPAContext &context,
 	double greenMean = 1.1636 * yMean - 0.4045 * cbMean - 0.7949 * crMean;
 	double blueMean = 1.1636 * yMean + 1.9912 * cbMean - 0.0250 * crMean;
 
+	frameContext.awb.temperatureK = estimateCCT(redMean, greenMean, blueMean);
+
 	/* Estimate the red and blue gains to apply in a grey world. */
 	double redGain = greenMean / (redMean + 1);
 	double blueGain = greenMean / (blueMean + 1);
 
 	/* Filter the values to avoid oscillations. */
 	double speed = 0.2;
-	redGain = speed * redGain + (1 - speed) * activeState.awb.gains.red;
+	redGain = speed * redGain + (1 - speed) * activeState.awb.gains.automatic.red;
-	blueGain = speed * blueGain + (1 - speed) * activeState.awb.gains.blue;
+	blueGain = speed * blueGain + (1 - speed) * activeState.awb.gains.automatic.blue;
 
 	/*
 	 * Gain values are unsigned integer value, range 0 to 4 with 8 bit
-	 * fractional part.
+	 * fractional part. Hardcode the green gain to 1.0.
 	 */
-	if (activeState.awb.autoEnabled) {
+	activeState.awb.gains.automatic.red = std::clamp(redGain, 0.0, 1023.0 / 256);
-		activeState.awb.gains.red = std::clamp(redGain, 0.0, 1023.0 / 256);
+	activeState.awb.gains.automatic.blue = std::clamp(blueGain, 0.0, 1023.0 / 256);
-		activeState.awb.gains.blue = std::clamp(blueGain, 0.0, 1023.0 / 256);
+	activeState.awb.gains.automatic.green = 1.0;
-	}
-	/* Hardcode the green gain to 1.0. */
-	activeState.awb.gains.green = 1.0;
 
-	activeState.awb.temperatureK = estimateCCT(redMean, greenMean, blueMean);
+	LOG(RkISP1Awb, Debug) << "Gain found for red: " << activeState.awb.gains.automatic.red
-
+			      << " and for blue: " << activeState.awb.gains.automatic.blue;
-	LOG(RkISP1Awb, Debug) << "Gain found for red: " << context.activeState.awb.gains.red
-			      << " and for blue: " << context.activeState.awb.gains.blue;
 }
 
 REGISTER_IPA_ALGORITHM(Awb, "Awb")

src/ipa/rkisp1/ipa_context.cpp

@@ -120,17 +120,29 @@ namespace libcamera::ipa::rkisp1 {
  * \struct IPAActiveState::awb.gains
  * \brief White balance gains
  *
- * \var IPAActiveState::awb.gains.red
+ * \struct IPAActiveState::awb.gains.manual
- * \brief White balance gain for R channel
+ * \brief Manual white balance gains (set through requests)
  *
- * \var IPAActiveState::awb.gains.green
+ * \var IPAActiveState::awb.gains.manual.red
- * \brief White balance gain for G channel
+ * \brief Manual white balance gain for R channel
  *
- * \var IPAActiveState::awb.gains.blue
+ * \var IPAActiveState::awb.gains.manual.green
- * \brief White balance gain for B channel
+ * \brief Manual white balance gain for G channel
  *
- * \var IPAActiveState::awb.temperatureK
+ * \var IPAActiveState::awb.gains.manual.blue
- * \brief Estimated color temperature
+ * \brief Manual white balance gain for B channel
+ *
+ * \struct IPAActiveState::awb.gains.automatic
+ * \brief Automatic white balance gains (computed by the algorithm)
+ *
+ * \var IPAActiveState::awb.gains.automatic.red
+ * \brief Automatic white balance gain for R channel
+ *
+ * \var IPAActiveState::awb.gains.automatic.green
+ * \brief Automatic white balance gain for G channel
+ *
+ * \var IPAActiveState::awb.gains.automatic.blue
+ * \brief Automatic white balance gain for B channel
  *
  * \var IPAActiveState::awb.autoEnabled
  * \brief Whether the Auto White Balance algorithm is enabled
@@ -201,6 +213,29 @@ namespace libcamera::ipa::rkisp1 {
  * The gain should be adapted to the sensor specific gain code before applying.
  */
 
+/**
+ * \var IPAFrameContext::awb
+ * \brief Automatic White Balance parameters for this frame
+ *
+ * \struct IPAFrameContext::awb.gains
+ * \brief White balance gains
+ *
+ * \var IPAFrameContext::awb.gains.red
+ * \brief White balance gain for R channel
+ *
+ * \var IPAFrameContext::awb.gains.green
+ * \brief White balance gain for G channel
+ *
+ * \var IPAFrameContext::awb.gains.blue
+ * \brief White balance gain for B channel
+ *
+ * \var IPAFrameContext::awb.temperatureK
+ * \brief Estimated color temperature
+ *
+ * \var IPAFrameContext::awb.autoEnabled
+ * \brief Whether the Auto White Balance algorithm is enabled
+ */
+
 /**
  * \var IPAFrameContext::sensor
  * \brief Sensor configuration that used been used for this frame

src/ipa/rkisp1/ipa_context.h

@@ -54,14 +54,20 @@ struct IPAActiveState {
 		double gain;
 	} agc;
 
+	struct {
 		struct {
 			struct {
 				double red;
 				double green;
 				double blue;
+			} manual;
+			struct {
+				double red;
+				double green;
+				double blue;
+			} automatic;
 		} gains;
 
-		double temperatureK;
 		bool autoEnabled;
 	} awb;
 
@@ -90,6 +96,17 @@ struct IPAFrameContext : public FrameContext {
 		double gain;
 	} agc;
 
+	struct {
+		struct {
+			double red;
+			double green;
+			double blue;
+		} gains;
+
+		double temperatureK;
+		bool autoEnabled;
+	} awb;
+
 	struct {
 		uint32_t exposure;
 		double gain;