[libcamera-devel] [PATCH] ipa: raspberrypi: awb: Better handling of how we disable AWB

[David Plowman]

We now handle disabling ("pausing") AWB in the same way as
AEC/AGC. Instead of letting the pause flag be set so that the code
never runs at all, we instead fix the manual settings to the current
values (but continue to be called).

The algorithm does not restart any calculations in this state, but
continues to add AWB metadata to every frame. Therefore certain other
algorithms that want to know it (CCM and ALSC, for example) can still
find it.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 src/ipa/raspberrypi/controller/rpi/awb.cpp | 21 +++++++++++++++++++++
 src/ipa/raspberrypi/controller/rpi/awb.hpp |  4 ++++
 2 files changed, 25 insertions(+)

diff --git a/src/ipa/raspberrypi/controller/rpi/awb.cpp b/src/ipa/raspberrypi/controller/rpi/awb.cpp
index 5cfd33a3..1ad912c7 100644
--- a/src/ipa/raspberrypi/controller/rpi/awb.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/awb.cpp
@@ -172,6 +172,27 @@ void Awb::Initialise()
 	async_results_ = sync_results_;
 }
 
+bool Awb::IsPaused() const
+{
+	return false;
+}
+
+void Awb::Pause()
+{
+	// "Pause" by fixing everything to the most recent values.
+	manual_r_ = sync_results_.gain_r = prev_sync_results_.gain_r;
+	manual_b_ = sync_results_.gain_b = prev_sync_results_.gain_b;
+	sync_results_.gain_g = prev_sync_results_.gain_g;
+	sync_results_.gain_g = prev_sync_results_.gain_g;
+	sync_results_.temperature_K = prev_sync_results_.temperature_K;
+}
+
+void Awb::Resume()
+{
+	manual_r_ = 0.0;
+	manual_b_ = 0.0;
+}
+
 unsigned int Awb::GetConvergenceFrames() const
 {
 	// If not in auto mode, there is no convergence
diff --git a/src/ipa/raspberrypi/controller/rpi/awb.hpp b/src/ipa/raspberrypi/controller/rpi/awb.hpp
index 8af1f27c..ac3dca6f 100644
--- a/src/ipa/raspberrypi/controller/rpi/awb.hpp
+++ b/src/ipa/raspberrypi/controller/rpi/awb.hpp
@@ -83,6 +83,10 @@ public:
 	char const *Name() const override;
 	void Initialise() override;
 	void Read(boost::property_tree::ptree const &params) override;
+	// AWB handles "pausing" for itself.
+	bool IsPaused() const override;
+	void Pause() override;
+	void Resume() override;
 	unsigned int GetConvergenceFrames() const override;
 	void SetMode(std::string const &name) override;
 	void SetManualGains(double manual_r, double manual_b) override;
-- 
2.30.2