[libcamera-devel] [PATCH v3 3/3] libcamera: pipeline: raspberrypi: Update sensor's V4L2_CID_NOTIFY_GAINS control
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Wed Jan 5 20:47:44 CET 2022
Hi David,
Thank you for the patch.
On Wed, Jan 05, 2022 at 03:55:39PM +0000, David Plowman wrote:
> If the sensor exposes the V4L2_CID_NOTIFY_GAINS control, assume it
> means the sensor wants to be told the latest colour gains.
>
> We store whether the control exists and if so its default value, to
> save us checking for it on every frame.
>
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
> .../pipeline/raspberrypi/raspberrypi.cpp | 31 +++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index b5c687da..4adef952 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -264,6 +264,12 @@ public:
>
> unsigned int dropFrameCount_;
>
> + /*
> + * If set, this stores the value that represets a gain of one for
> + * the V4L2_CID_NOTIFY_GAINS control.
> + */
> + std::optional<int32_t> notifyGainsUnity_;
A plain int32_t would be enough, as a zero value isn't valid. Up to
you.
> +
> private:
> void checkRequestCompleted();
> void fillRequestMetadata(const ControlList &bufferControls,
> @@ -1191,6 +1197,15 @@ int PipelineHandlerRPi::registerCamera(MediaDevice *unicam, MediaDevice *isp)
> /* Initialize the camera properties. */
> data->properties_ = data->sensor_->properties();
>
> + /*
> + * The V4L2_CID_NOTIFY_GAINS control, if present, is used to inform the
> + * sensor of the colour gains. It is defined to be a linear gain where
> + * the default value represents a gain of exactly one.
> + */
> + auto it = data->sensor_->controls().find(V4L2_CID_NOTIFY_GAINS);
> + if (it != data->sensor_->controls().end())
> + data->notifyGainsUnity_ = it->second.def().get<int32_t>();
> +
> /*
> * Set a default value for the ScalerCropMaximum property to show
> * that we support its use, however, initialise it to zero because
> @@ -1495,6 +1510,22 @@ void RPiCameraData::statsMetadataComplete(uint32_t bufferId, const ControlList &
> Request *request = requestQueue_.front();
> request->metadata().merge(controls);
>
> + /*
> + * Inform the sensor of the latest colour gains if it has the
> + * V4L2_CID_NOTIFY_GAINS control (which means notifyGainsUnity_ is set).
> + */
> + if (notifyGainsUnity_ && controls.contains(libcamera::controls::ColourGains)) {
> + libcamera::Span<const float> colourGains = controls.get(libcamera::controls::ColourGains);
> + /* The control wants linear gains in the order B, Gb, Gr, R. */
> + ControlList ctrls(sensor_->controls());
> + std::array<int32_t, 4> gains = { static_cast<int32_t>(colourGains[1] * *notifyGainsUnity_),
> + *notifyGainsUnity_, *notifyGainsUnity_,
> + static_cast<int32_t>(colourGains[0] * *notifyGainsUnity_) };
Let's shorten the lines a bit:
std::array<int32_t, 4> gains{
static_cast<int32_t>(colourGains[1] * *notifyGainsUnity_),
*notifyGainsUnity_,
*notifyGainsUnity_,
static_cast<int32_t>(colourGains[0] * *notifyGainsUnity_)
};
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> + ctrls.set(V4L2_CID_NOTIFY_GAINS, Span<const int32_t>{ gains });
> +
> + sensor_->setControls(&ctrls);
> + }
> +
> state_ = State::IpaComplete;
> + ctrls.set(V4L2_CID_NOTIFY_GAINS, Span<const int32_t>{ gains });
> +
> + sensor_->setControls(&ctrls);
> + }
> +
> state_ = State::IpaComplete;
> handleState();
> }
--
Regards,
Laurent Pinchart
More information about the libcamera-devel
mailing list