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

[Stefan Klug]

Hi Jacopo,

On Tue, Jul 02, 2024 at 10:45:26AM +0200, Jacopo Mondi wrote:
> 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 ?

Hm good question. What I wanted to achieve:
- black level data should be contained in the metadata so that we can
  capture raws with blacklevel
- It should be possible to overwrite the values with a tuning file, for
  cases, where you take the tuning files with a libcamera that doesn't
  know the correct black level for that sensor (it's arguable if that's
  an acceptable usecase, but I think it happens in practice)

So I could either move the whole configure logic into the ipa core, or
add raw support to the blc algorithm. To me it feels better to keep all
the black level related stuff in one place. But I'm ok with changing
that.

> 
> >  }
> >
> >  /**
> > @@ -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 ?

Just to clarify: That also means the yaml reading code should be moved
there, right?

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
> >