ipa: rkisp1: Introduce AWB

The RkISP1 ISP calculates a mean value for Y, Cr and Cb at each frame.
There is a RGB mode which could theoretically give us the values for R,
G and B directly, but it seems to be failing right now.

Convert those values into R, G and B and estimate the gain to apply in a
grey world.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/ipa/rkisp1/ipa_context.cpp b/src/ipa/rkisp1/ipa_context.cpp
index 4a1ab058..1559d3ff 100644
--- a/src/ipa/rkisp1/ipa_context.cpp
+++ b/src/ipa/rkisp1/ipa_context.cpp
@@ -82,6 +82,14 @@ namespace libcamera::ipa::rkisp1 {
  */
 
 /**
+ * \var IPASessionConfiguration::awb
+ * \brief AWB parameters configuration of the IPA
+ *
+ * \var IPASessionConfiguration::awb.measureWindow
+ * \brief AWB measure window
+ */
+
+/**
  * \var IPASessionConfiguration::sensor
  * \brief Sensor-specific configuration of the IPA
  *
@@ -106,6 +114,26 @@ namespace libcamera::ipa::rkisp1 {
  */
 
 /**
+ * \var IPAFrameContext::awb
+ * \brief Context for the Automatic White Balance algorithm
+ *
+ * \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::sensor
  * \brief Effective sensor values
  *