ipa: ipu3: Fill AGC and AWB metadata in algorithms

Fill the frame metadata in the AGC and AWB algorithm's prepare()
function. This removes the need to fill metadata manually in the IPA
module's processStatsBuffer() function.

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

src/ipa/ipu3/algorithms/agc.cpp

@@ -14,6 +14,7 @@
 #include <libcamera/base/log.h>
 #include <libcamera/base/utils.h>
 
+#include <libcamera/control_ids.h>
 #include <libcamera/ipa/core_ipa_interface.h>
 
 #include "libipa/histogram.h"
@@ -328,7 +329,7 @@ double Agc::estimateLuminance(IPAActiveState &activeState,
 void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 		  IPAFrameContext &frameContext,
 		  const ipu3_uapi_stats_3a *stats,
-		  [[maybe_unused]] ControlList &metadata)
+		  ControlList &metadata)
 {
 	/*
 	 * Estimate the gain needed to have the proportion of pixels in a given
@@ -365,6 +366,19 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 
 	computeExposure(context, frameContext, yGain, iqMeanGain);
 	frameCount_++;
+
+	utils::Duration exposureTime = context.configuration.sensor.lineDuration
+				     * frameContext.sensor.exposure;
+	metadata.set(controls::AnalogueGain, frameContext.sensor.gain);
+	metadata.set(controls::ExposureTime, exposureTime.get<std::micro>());
+
+	/* \todo Use VBlank value calculated from each frame exposure. */
+	uint32_t vTotal = context.configuration.sensor.size.height
+			+ context.configuration.sensor.defVBlank;
+	utils::Duration frameDuration = context.configuration.sensor.lineDuration
+				      * vTotal;
+	metadata.set(controls::FrameDuration, frameDuration.get<std::micro>());
+
 }
 
 REGISTER_IPA_ALGORITHM(Agc, "Agc")