[PATCH v1 2/6] ipa: rkisp1: awb: Load white balance gains from tuning file

[Kieran Bingham]

Quoting Stefan Klug (2024-08-05 13:05:03)
> For the implementation of a manual colour temperature setting, it is
> necessary to read predefined colour gains per colour temperature from
> the tuning file. Implement this in a backwards compatible way. If no
> gains are contained in the tuning file, loading just continues as
> before.
> 
> Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
> ---
>  src/ipa/rkisp1/algorithms/awb.cpp | 18 ++++++++++++++++++
>  src/ipa/rkisp1/algorithms/awb.h   |  6 ++++++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
> index 4ccafd48dedd..957d24fe3425 100644
> --- a/src/ipa/rkisp1/algorithms/awb.cpp
> +++ b/src/ipa/rkisp1/algorithms/awb.cpp
> @@ -39,6 +39,24 @@ Awb::Awb()
>  {
>  }
>  
> +/**
> + * \copydoc libcamera::ipa::Algorithm::init
> + */
> +int Awb::init(IPAContext &context, const YamlObject &tuningData)
> +{
> +       MatrixInterpolator<double, 2, 1> gains;
> +       int ret = gains.readYaml(tuningData["gains"], "ct", "gains");

Do we have a way to check if there are gains set at all? If there are no
gains set in the yaml - we wouldn't report a warning at all I'd expect?

(And presumably we wouldn't expose/report a manual color temperature
control as setable either?)

> +       if (ret < 0)
> +               LOG(RkISP1Awb, Warning)
> +                       << "Failed to parse 'gains' "
> +                       << "parameter from tuning file; "
> +                       << "rgb gains will not be set based on colour temperature";
> +       else
> +               gains_ = gains;
> +
> +       return 0;
> +}
> +
>  /**
>   * \copydoc libcamera::ipa::Algorithm::configure
>   */
> diff --git a/src/ipa/rkisp1/algorithms/awb.h b/src/ipa/rkisp1/algorithms/awb.h
> index 06c92896e2dc..a010e6d1cb3c 100644
> --- a/src/ipa/rkisp1/algorithms/awb.h
> +++ b/src/ipa/rkisp1/algorithms/awb.h
> @@ -7,6 +7,10 @@
>  
>  #pragma once
>  
> +#include <optional>
> +
> +#include "libipa/matrix_interpolator.h"
> +
>  #include "algorithm.h"
>  
>  namespace libcamera {
> @@ -19,6 +23,7 @@ public:
>         Awb();
>         ~Awb() = default;
>  
> +       int init(IPAContext &context, const YamlObject &tuningData) override;
>         int configure(IPAContext &context, const IPACameraSensorInfo &configInfo) override;
>         void queueRequest(IPAContext &context, const uint32_t frame,
>                           IPAFrameContext &frameContext,
> @@ -34,6 +39,7 @@ public:
>  private:
>         uint32_t estimateCCT(double red, double green, double blue);
>  
> +       std::optional<MatrixInterpolator<double, 2, 1>> gains_;
>         bool rgbMode_;
>  };
>  
> -- 
> 2.43.0
>