[libcamera-devel] [PATCH v2] libcamera: pipeline: raspberrypi: Fix scaler crop when sensor is configured

David Plowman david.plowman at raspberrypi.com
Thu Mar 3 15:32:01 CET 2022


Hi Kieran

Thanks for review number 2!

On Thu, 3 Mar 2022 at 14:20, Kieran Bingham
<kieran.bingham at ideasonboard.com> wrote:
>
> Hi David,
>
> Quoting David Plowman (2022-03-03 12:11:13)
> > We must calculate the initial scaler crop when the camera is
> > configured, otherwise the metadata will report this rectangle as being
> > all zeroes.
> >
> > Because the calculation is identical to that performed later in handling
> > the scaler crop control, we factor it into a small helper function,
> > RPiCameraData::scaleIspCrop.
> >
> > Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> > ---
> >  .../pipeline/raspberrypi/raspberrypi.cpp      | 20 ++++++++++++++++---
> >  1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > index 29bff9d6..eede78e6 100644
> > --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > @@ -212,6 +212,7 @@ public:
> >         void handleStreamBuffer(FrameBuffer *buffer, RPi::Stream *stream);
> >         void handleExternalBuffer(FrameBuffer *buffer, RPi::Stream *stream);
> >         void handleState();
> > +       Rectangle scaleIspCrop(const Rectangle &ispCrop) const;
> >         void applyScalerCrop(const ControlList &controls);
> >
> >         std::unique_ptr<ipa::RPi::IPAProxyRPi> ipa_;
> > @@ -887,6 +888,9 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
> >         if (ret)
> >                 LOG(RPI, Error) << "Failed to configure the IPA: " << ret;
> >
> > +       /* Set the scaler crop to the value we are using (scaled to native sensor coordinates). */
> > +       data->scalerCrop_ = data->scaleIspCrop(data->ispCrop_);
> > +
> >         /*
> >          * Configure the Unicam embedded data output format only if the sensor
> >          * supports it.
> > @@ -1974,6 +1978,18 @@ void RPiCameraData::checkRequestCompleted()
> >         }
> >  }
> >
> > +Rectangle RPiCameraData::scaleIspCrop(const Rectangle &ispCrop) const
> > +{
> > +       /*
> > +        * Scale a crop rectangle defined in the ISP's coordinates into native sensor
> > +        * coordinates.
> > +        */
> > +       Rectangle nativeCrop = ispCrop.scaledBy(sensorInfo_.analogCrop.size(),
> > +                                               sensorInfo_.outputSize);
> > +       nativeCrop.translateBy(sensorInfo_.analogCrop.topLeft());
>
> I'm struggling to be sure, but this is what the code was before, so I'm
> sure it's fine... should the amount we translate by also be scaled?

I think it's right as it is. sensorInfo_.analogCrop is necessarily in
the "sensor's native coordinates", which nativeCrop also is by dint of
the line above, so it looks plausible to me...

David

>
> Or perhaps that's just to maintain the original cropping point.
>
> > +       return nativeCrop;
>
> I know it was only two lines, but I certainly prefer this, as it's now
> it's more clear (and more documented, and self-documenting) for what is
> being returned.
>
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>
>
> > +}
> > +
> >  void RPiCameraData::applyScalerCrop(const ControlList &controls)
> >  {
> >         if (controls.contains(controls::ScalerCrop)) {
> > @@ -2006,9 +2022,7 @@ void RPiCameraData::applyScalerCrop(const ControlList &controls)
> >                          * used. But we must first rescale that from ISP (camera mode) pixels
> >                          * back into sensor native pixels.
> >                          */
> > -                       scalerCrop_ = ispCrop_.scaledBy(sensorInfo_.analogCrop.size(),
> > -                                                       sensorInfo_.outputSize);
> > -                       scalerCrop_.translateBy(sensorInfo_.analogCrop.topLeft());
> > +                       scalerCrop_ = scaleIspCrop(ispCrop_);
> >                 }
> >         }
> >  }
> > --
> > 2.30.2
> >


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