[libcamera-devel] [PATCH 4/5] ipa: rpi: agc: Add AgcChannelConstraint class

[David Plowman]

Hi Naush

Thanks for the review.

On Tue, 22 Aug 2023 at 13:46, Naushir Patuck <naush at raspberrypi.com> wrote:
>
> Hi David,
>
> Thank you for your work.
>
> On Mon, 31 Jul 2023 at 10:46, David Plowman via libcamera-devel
> <libcamera-devel at lists.libcamera.org> wrote:
> >
> > A channel constraint is somewhat similar to the upper/lower bound
> > constraints that we use elsewhere, but these constraints apply between
> > multiple AGC channels. For example, it lets you say things like "don't
> > let the channel 1 total exposure be more than 8x that of channel 0",
> > and so on. By using both an upper and lower bound constraint, you
> > could fix one AGC channel always to be a fixed ratio of another.
> >
> > Also read a vector of them (if present) when loading the tuning file.
> >
> > Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> > ---
> >  src/ipa/rpi/controller/rpi/agc_channel.cpp | 42 ++++++++++++++++++++++
> >  src/ipa/rpi/controller/rpi/agc_channel.h   | 10 ++++++
> >  2 files changed, 52 insertions(+)
> >
> > diff --git a/src/ipa/rpi/controller/rpi/agc_channel.cpp b/src/ipa/rpi/controller/rpi/agc_channel.cpp
> > index ddec611f..ed8a3b30 100644
> > --- a/src/ipa/rpi/controller/rpi/agc_channel.cpp
> > +++ b/src/ipa/rpi/controller/rpi/agc_channel.cpp
> > @@ -173,6 +173,42 @@ readConstraintModes(std::map<std::string, AgcConstraintMode> &constraintModes,
> >         return { 0, first };
> >  }
> >
> > +int AgcChannelConstraint::read(const libcamera::YamlObject &params)
> > +{
> > +       std::string boundString = params["bound"].get<std::string>("");
> > +       transform(boundString.begin(), boundString.end(),
> > +                 boundString.begin(), ::toupper);
> > +       if (boundString != "UPPER" && boundString != "LOWER") {
> > +               LOG(RPiAgc, Error) << "AGC channelconstraint type should be UPPER or LOWER";
> > +               return -EINVAL;
> > +       }
> > +       bound = boundString == "UPPER" ? Bound::UPPER : Bound::LOWER;
> > +
> > +       auto value = params["factor"].get<double>();
> > +       if (!value)
> > +               return -EINVAL;
> > +       factor = *value;
> > +
> > +       return 0;
> > +}
> > +
> > +int readChannelConstraints(std::vector<AgcChannelConstraint> channelConstraints,
> > +                          const libcamera::YamlObject &params)
>
> Make this function static?

Will do.

>
>
> > +{
> > +       int ret = 0;
> > +
> > +       for (const auto &p : params.asList()) {
> > +               AgcChannelConstraint constraint;
> > +               ret = constraint.read(p);
> > +               if (ret)
> > +                       return ret;
> > +
> > +               channelConstraints.push_back(std::move(constraint));
>
> Do we need to move here?  Probably no practical difference though.

Yep, will change!

Thanks
David

>
> Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
>
> > +       }
> > +
> > +       return ret;
> > +}
> > +
> >  int AgcConfig::read(const libcamera::YamlObject &params)
> >  {
> >         LOG(RPiAgc, Debug) << "AgcConfig";
> > @@ -191,6 +227,12 @@ int AgcConfig::read(const libcamera::YamlObject &params)
> >         if (ret)
> >                 return ret;
> >
> > +       if (params.contains("channel_constraints")) {
> > +               ret = readChannelConstraints(channelConstraints, params["channel_constraints"]);
> > +               if (ret)
> > +                       return ret;
> > +       }
> > +
> >         ret = yTarget.read(params["y_target"]);
> >         if (ret)
> >                 return ret;
> > diff --git a/src/ipa/rpi/controller/rpi/agc_channel.h b/src/ipa/rpi/controller/rpi/agc_channel.h
> > index 0e3d44b0..446125ef 100644
> > --- a/src/ipa/rpi/controller/rpi/agc_channel.h
> > +++ b/src/ipa/rpi/controller/rpi/agc_channel.h
> > @@ -42,11 +42,21 @@ struct AgcConstraint {
> >
> >  typedef std::vector<AgcConstraint> AgcConstraintMode;
> >
> > +struct AgcChannelConstraint {
> > +       enum class Bound { LOWER = 0,
> > +                          UPPER = 1 };
> > +       Bound bound;
> > +       unsigned int channel;
> > +       double factor;
> > +       int read(const libcamera::YamlObject &params);
> > +};
> > +
> >  struct AgcConfig {
> >         int read(const libcamera::YamlObject &params);
> >         std::map<std::string, AgcMeteringMode> meteringModes;
> >         std::map<std::string, AgcExposureMode> exposureModes;
> >         std::map<std::string, AgcConstraintMode> constraintModes;
> > +       std::vector<AgcChannelConstraint> channelConstraints;
> >         Pwl yTarget;
> >         double speed;
> >         uint16_t startupFrames;
> > --
> > 2.30.2
> >