[PATCH 4/5] ipa: rkisp1: blc: Report sensor black levels in metadata

[Stefan Klug]

On Tue, Jul 02, 2024 at 12:49:59PM +0100, Kieran Bingham wrote:
> Quoting Jacopo Mondi (2024-07-02 09:45:26)
> > Hi Stefan
> > 
> > On Mon, Jul 01, 2024 at 04:38:27PM GMT, Stefan Klug wrote:
> > > For the tuning process it is necessary to know the sensor black levels.
> > > Add them to the metadata.
> > >
> > > Additionally enable raw support for this algorithm and add it to
> > > uncalibrated.yaml, so that black levels get reported when capturing
> > > tuning images.
> > >
> > > Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
> > > ---
> > >  src/ipa/rkisp1/algorithms/blc.cpp     | 19 +++++++++++++++++++
> > >  src/ipa/rkisp1/algorithms/blc.h       |  5 ++++-
> > >  src/ipa/rkisp1/data/uncalibrated.yaml |  1 +
> > >  3 files changed, 24 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/src/ipa/rkisp1/algorithms/blc.cpp b/src/ipa/rkisp1/algorithms/blc.cpp
> > > index 0c39c3b47da5..a9f76b87d15a 100644
> > > --- a/src/ipa/rkisp1/algorithms/blc.cpp
> > > +++ b/src/ipa/rkisp1/algorithms/blc.cpp
> > > @@ -9,6 +9,8 @@
> > >
> > >  #include <libcamera/base/log.h>
> > >
> > > +#include <libcamera/control_ids.h>
> > > +
> > >  #include "libcamera/internal/yaml_parser.h"
> > >
> > >  /**
> > > @@ -38,6 +40,7 @@ LOG_DEFINE_CATEGORY(RkISP1Blc)
> > >  BlackLevelCorrection::BlackLevelCorrection()
> > >       : tuningParameters_(false)
> > >  {
> > > +     supportsRaw_ = true;
> > 
> > Does it support raw for real ? Doesn't BLC require going through the
> > ISP ?
> 
> Oh That's interesting, - I didn't realise we had this switch
> 
> Any preference for adding it in the constructor rather than extending
> the initiasliser list and putting it after tuningParameters_(false) ?

Actually I looked that up, because I had that question myself.
supportsRaw_ is defined in the base class. The initializer list can only
initialize variables from the current class. So assignments in the
constructor are the only option.

> 
> >
> > >  }
> > >
> > >  /**
> > > @@ -107,6 +110,22 @@ void BlackLevelCorrection::prepare([[maybe_unused]] IPAContext &context,
> > >       params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_BLS;
> > >  }
> > >
> > > +/**
> > > + * \copydoc libcamera::ipa::Algorithm::process
> > > + */
> > > +void BlackLevelCorrection::process([[maybe_unused]] IPAContext &context,
> > > +                                [[maybe_unused]] const uint32_t frame,
> > > +                                [[maybe_unused]] IPAFrameContext &frameContext,
> > > +                                [[maybe_unused]] const rkisp1_stat_buffer *stats,
> > > +                                [[maybe_unused]] ControlList &metadata)
> > > +{
> > > +     metadata.set(controls::SensorBlackLevels,
> > > +                  { static_cast<int32_t>(blackLevelRed_),
> > > +                    static_cast<int32_t>(blackLevelGreenR_),
> > > +                    static_cast<int32_t>(blackLevelGreenB_),
> > > +                    static_cast<int32_t>(blackLevelBlue_) });
> > 
> > As black levels do not change you can store them in the context and
> > populate the metadata in the main IPA module instead of making this
> > algorithm support raw ?
> 
> 
> If a sensor exposes a control to allow setting the black level, I expect
> this component would be responsible for reporting that and then setting
> it to the v4l2-subdev driver?

Yes, if we ever implement such a driver :-)

Best regards,
Stefan

> 
> > 
> > > +}
> > > +
> > >  REGISTER_IPA_ALGORITHM(BlackLevelCorrection, "BlackLevelCorrection")
> > >
> > >  } /* namespace ipa::rkisp1::algorithms */
> > > diff --git a/src/ipa/rkisp1/algorithms/blc.h b/src/ipa/rkisp1/algorithms/blc.h
> > > index 460ebcc15739..4ecac233f88b 100644
> > > --- a/src/ipa/rkisp1/algorithms/blc.h
> > > +++ b/src/ipa/rkisp1/algorithms/blc.h
> > > @@ -23,7 +23,10 @@ public:
> > >       void prepare(IPAContext &context, const uint32_t frame,
> > >                    IPAFrameContext &frameContext,
> > >                    rkisp1_params_cfg *params) override;
> > > -
> > > +     void process(IPAContext &context, const uint32_t frame,
> > > +                  IPAFrameContext &frameContext,
> > > +                  const rkisp1_stat_buffer *stats,
> > > +                  ControlList &metadata) override;
> > >  private:
> > >       bool tuningParameters_;
> > >       int16_t blackLevelRed_;
> > > diff --git a/src/ipa/rkisp1/data/uncalibrated.yaml b/src/ipa/rkisp1/data/uncalibrated.yaml
> > > index a7bbd8d84263..609012967e02 100644
> > > --- a/src/ipa/rkisp1/data/uncalibrated.yaml
> > > +++ b/src/ipa/rkisp1/data/uncalibrated.yaml
> > > @@ -5,4 +5,5 @@ version: 1
> > >  algorithms:
> > >    - Agc:
> > >    - Awb:
> > > +  - BlackLevelCorrection:
> > >  ...
> > > --
> > > 2.43.0
> > >