ipa: ipu3: Introduce a modular tone mapping algorithm

Introduce a new algorithm to manage the tone mapping handling of the
IPU3.

The initial algorithm is chosen to configure the gamma contrast curve
which moves the implementation out of AWB for simplicity. As it is
initialised with a default gamma value of 1.1, there is no need to use
the default table at initialisation anymore.

This demonstrates the way to use process() call when the EventStatReady
comes in. The function calculates the LUT in the context of a frame, and
when prepare() is called, the parameters are filled with the updated
values.

AGC is modified to take the new process interface into account.

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

1 files changed, 16 insertions, 1 deletions

diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index 4d5b0af1..3713b07b 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -30,6 +30,7 @@
 #include "libcamera/internal/mapped_framebuffer.h"
 
 #include "algorithms/algorithm.h"
+#include "algorithms/tone_mapping.h"
 #include "ipu3_agc.h"
 #include "ipu3_awb.h"
 #include "libipa/camera_sensor_helper.h"
@@ -91,6 +92,17 @@
  * \brief BDS output size configured by the pipeline handler
  */
 
+/**
+ * \struct IPAFrameContext::toneMapping
+ * \brief Context for ToneMapping and Gamma control
+ *
+ * \var IPAFrameContext::toneMapping::gammaCorrection
+ * \brief Per-pixel tone mapping implemented as a LUT
+ *
+ * The LUT structure is defined by the IPU3 kernel interface. See
+ * <linux/intel-ipu3.h> struct ipu3_uapi_gamma_corr_lut for further details.
+ */
+
 static constexpr uint32_t kMaxCellWidthPerSet = 160;
 static constexpr uint32_t kMaxCellHeightPerSet = 56;
 
@@ -225,6 +237,9 @@ int IPAIPU3::init(const IPASettings &settings,
 
 	*ipaControls = ControlInfoMap(std::move(controls), controls::controls);
 
+	/* Construct our Algorithms */
+	algorithms_.push_back(std::make_unique<algorithms::ToneMapping>());
+
 	return 0;
 }
 
@@ -423,7 +438,7 @@ void IPAIPU3::fillParams(unsigned int frame, ipu3_uapi_params *params)
 		algo->prepare(context_, &params_);
 
 	if (agcAlgo_->updateControls())
-		awbAlgo_->updateWbParameters(params_, agcAlgo_->gamma());
+		awbAlgo_->updateWbParameters(params_);
 
 	*params = params_;