libcamera: software_isp: Store color temperature to metadata

Image color temperature is a piece of information that should be
reported in metadata, let's put it there.

Metadata is currently not reported in simple pipeline but we should make
at least newly added information ready to be reported.

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

src/ipa/simple/algorithms/awb.cpp

@@ -12,6 +12,8 @@
 
 #include <libcamera/base/log.h>
 
+#include <libcamera/control_ids.h>
+
 #include "libipa/colours.h"
 #include "simple/ipa_context.h"
 
@@ -34,7 +36,7 @@ void Awb::process(IPAContext &context,
 		  [[maybe_unused]] const uint32_t frame,
 		  [[maybe_unused]] IPAFrameContext &frameContext,
 		  const SwIspStats *stats,
-		  [[maybe_unused]] ControlList &metadata)
+		  ControlList &metadata)
 {
 	const SwIspStats::Histogram &histogram = stats->yHistogram;
 	const uint8_t blackLevel = context.activeState.blc.level;
@@ -64,6 +66,7 @@ void Awb::process(IPAContext &context,
 
 	RGB<double> rgbGains{ { 1 / gains.r(), 1 / gains.g(), 1 / gains.b() } };
 	context.activeState.awb.temperatureK = estimateCCT(rgbGains);
+	metadata.set(controls::ColourTemperature, context.activeState.awb.temperatureK);
 
 	LOG(IPASoftAwb, Debug)
 		<< "gain R/B: " << gains << "; temperature: "