[libcamera-devel] [PATCH v3 4/4] use std::optional to handle invalid control values

Laurent Pinchart laurent.pinchart at ideasonboard.com
Tue Apr 19 22:46:25 CEST 2022


Hi Christian,

Thank you for the patch.

On Fri, Apr 08, 2022 at 02:42:31AM +0100, Christian Rauch via libcamera-devel wrote:
> Previously, ControlList::get<T>() would use default constructed objects to
> indicate that a ControlList does not have the requested Control. This has
> several disadvantages: 1) It requires types to be default constructible,
> 2) it does not differentiate between a default constructed object and an
> object that happens to have the same state as a default constructed object.
> 
> std::optional<T> additionally stores the information if the object is valid
> or not, and therefore is more expressive than a default constructed object.
> 
> Signed-off-by: Christian Rauch <Rauch.Christian at gmx.de>
> ---
>  include/libcamera/controls.h                      |  6 +++---
>  src/cam/main.cpp                                  |  4 ++--
>  src/ipa/raspberrypi/raspberrypi.cpp               |  2 +-
>  src/libcamera/pipeline/ipu3/ipu3.cpp              |  9 ++++-----
>  .../pipeline/raspberrypi/raspberrypi.cpp          |  9 +++++----
>  src/qcam/dng_writer.cpp                           | 15 +++++++++------
>  6 files changed, 24 insertions(+), 21 deletions(-)
> 
> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
> index 665bcac1..57b777e9 100644
> --- a/include/libcamera/controls.h
> +++ b/include/libcamera/controls.h
> @@ -167,7 +167,7 @@ public:
> 
>  		using V = typename T::value_type;
>  		const V *value = reinterpret_cast<const V *>(data().data());
> -		return { value, numElements_ };
> +		return T{ value, numElements_ };
>  	}
> 
>  #ifndef __DOXYGEN__
> @@ -373,11 +373,11 @@ public:
>  	bool contains(unsigned int id) const;
> 
>  	template<typename T>
> -	T get(const Control<T> &ctrl) const
> +	std::optional<T> get(const Control<T> &ctrl) const
>  	{
>  		const ControlValue *val = find(ctrl.id());
>  		if (!val)
> -			return T{};
> +			return std::nullopt;
> 
>  		return val->get<T>();
>  	}
> diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> index c7f664b9..853a78ed 100644
> --- a/src/cam/main.cpp
> +++ b/src/cam/main.cpp
> @@ -293,7 +293,7 @@ std::string CamApp::cameraName(const Camera *camera)
>  	 * is only used if the location isn't present or is set to External.
>  	 */
>  	if (props.contains(properties::Location)) {
> -		switch (props.get(properties::Location)) {
> +		switch (props.get(properties::Location).value_or(int32_t{})) {
>  		case properties::CameraLocationFront:
>  			addModel = false;
>  			name = "Internal front camera ";
> @@ -313,7 +313,7 @@ std::string CamApp::cameraName(const Camera *camera)
>  		 * If the camera location is not availble use the camera model
>  		 * to build the camera name.
>  		 */
> -		name = "'" + props.get(properties::Model) + "' ";
> +		name = "'" + props.get(properties::Model).value_or(std::string{}) + "' ";
>  	}
> 
>  	name += "(" + camera->id() + ")";
> diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
> index 5a5cdf66..93b32e94 100644
> --- a/src/ipa/raspberrypi/raspberrypi.cpp
> +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> @@ -934,7 +934,7 @@ void IPARPi::returnEmbeddedBuffer(unsigned int bufferId)
> 
>  void IPARPi::prepareISP(const ipa::RPi::ISPConfig &data)
>  {
> -	int64_t frameTimestamp = data.controls.get(controls::SensorTimestamp);
> +	int64_t frameTimestamp = data.controls.get(controls::SensorTimestamp).value_or(int64_t{});
>  	RPiController::Metadata lastMetadata;
>  	Span<uint8_t> embeddedBuffer;
> 
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index 60e01917..394221cb 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -1146,7 +1146,7 @@ int PipelineHandlerIPU3::registerCameras()
>  		/* Convert the sensor rotation to a transformation */
>  		int32_t rotation = 0;
>  		if (data->properties_.contains(properties::Rotation))
> -			rotation = data->properties_.get(properties::Rotation);
> +			rotation = data->properties_.get(properties::Rotation).value_or(int32_t{});
>  		else
>  			LOG(IPU3, Warning) << "Rotation control not exposed by "
>  					   << cio2->sensor()->id()
> @@ -1341,7 +1341,7 @@ void IPU3CameraData::imguOutputBufferReady(FrameBuffer *buffer)
>  	request->metadata().set(controls::draft::PipelineDepth, 3);
>  	/* \todo Actually apply the scaler crop region to the ImgU. */
>  	if (request->controls().contains(controls::ScalerCrop))
> -		cropRegion_ = request->controls().get(controls::ScalerCrop);
> +		cropRegion_ = request->controls().get(controls::ScalerCrop).value_or(Rectangle{});
>  	request->metadata().set(controls::ScalerCrop, cropRegion_);
> 
>  	if (frameInfos_.tryComplete(info))
> @@ -1442,7 +1442,7 @@ void IPU3CameraData::statBufferReady(FrameBuffer *buffer)
>  	ev.op = ipa::ipu3::EventStatReady;
>  	ev.frame = info->id;
>  	ev.bufferId = info->statBuffer->cookie();
> -	ev.frameTimestamp = request->metadata().get(controls::SensorTimestamp);
> +	ev.frameTimestamp = request->metadata().get(controls::SensorTimestamp).value_or(int64_t{});
>  	ev.sensorControls = info->effectiveSensorControls;
>  	ipa_->processEvent(ev);
>  }
> @@ -1477,8 +1477,7 @@ void IPU3CameraData::frameStart(uint32_t sequence)
>  	if (!request->controls().contains(controls::draft::TestPatternMode))
>  		return;
> 
> -	const int32_t testPatternMode = request->controls().get(
> -		controls::draft::TestPatternMode);
> +	const int32_t testPatternMode = request->controls().get(controls::draft::TestPatternMode).value_or(int32_t{});
> 
>  	int ret = cio2_.sensor()->setTestPatternMode(
>  		static_cast<controls::draft::TestPatternModeEnum>(testPatternMode));
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index 0fa294d4..63d57033 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -365,7 +365,7 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>  	 * error means the platform can never run. Let's just print a warning
>  	 * and continue regardless; the rotation is effectively set to zero.
>  	 */
> -	int32_t rotation = data_->sensor_->properties().get(properties::Rotation);
> +	int32_t rotation = data_->sensor_->properties().get(properties::Rotation).value_or(int32_t{});
>  	bool success;
>  	Transform rotationTransform = transformFromRotation(rotation, &success);
>  	if (!success)
> @@ -1696,7 +1696,8 @@ void RPiCameraData::statsMetadataComplete(uint32_t bufferId, const ControlList &
>  	 * V4L2_CID_NOTIFY_GAINS control (which means notifyGainsUnity_ is set).
>  	 */
>  	if (notifyGainsUnity_ && controls.contains(libcamera::controls::ColourGains)) {
> -		libcamera::Span<const float, 2> colourGains = controls.get(libcamera::controls::ColourGains);
> +		libcamera::Span<const float, 2> colourGains =
> +			controls.get(libcamera::controls::ColourGains).value_or(libcamera::Span<const float, 2>({ 0, 0 }));

This is too long, we have a strick limit at 120 characters.

Do we need the value_or() here, given that it duplicates the
controls.contains() check ? I would expect either

	if (notifyGainsUnity_ && controls.contains(libcamera::controls::ColourGains)) {
		libcamera::Span<const float, 2> colourGains =
			controls.get(libcamera::controls::ColourGains).value();

or

	std::optional<...> colourGainsCtrl =
		controls.get(libcamera::controls::ColourGains);
	if (notifyGainsUnity_ && colourGainsCtrl) {
		libcamera::Span<const float, 2> colourGains = colourGainsCtrl.value();

Same in quite a few locations below.

>  		/* The control wants linear gains in the order B, Gb, Gr, R. */
>  		ControlList ctrls(sensor_->controls());
>  		std::array<int32_t, 4> gains{
> @@ -2031,7 +2032,7 @@ Rectangle RPiCameraData::scaleIspCrop(const Rectangle &ispCrop) const
>  void RPiCameraData::applyScalerCrop(const ControlList &controls)
>  {
>  	if (controls.contains(controls::ScalerCrop)) {
> -		Rectangle nativeCrop = controls.get<Rectangle>(controls::ScalerCrop);
> +		Rectangle nativeCrop = controls.get<Rectangle>(controls::ScalerCrop).value_or(Rectangle{});
> 
>  		if (!nativeCrop.width || !nativeCrop.height)
>  			nativeCrop = { 0, 0, 1, 1 };
> @@ -2069,7 +2070,7 @@ void RPiCameraData::fillRequestMetadata(const ControlList &bufferControls,
>  					Request *request)
>  {
>  	request->metadata().set(controls::SensorTimestamp,
> -				bufferControls.get(controls::SensorTimestamp));
> +				bufferControls.get(controls::SensorTimestamp).value_or(int64_t{}));
> 
>  	request->metadata().set(controls::ScalerCrop, scalerCrop_);
>  }
> diff --git a/src/qcam/dng_writer.cpp b/src/qcam/dng_writer.cpp
> index 2fb527d8..030432e3 100644
> --- a/src/qcam/dng_writer.cpp
> +++ b/src/qcam/dng_writer.cpp
> @@ -392,7 +392,7 @@ int DNGWriter::write(const char *filename, const Camera *camera,
>  	TIFFSetField(tif, TIFFTAG_MAKE, "libcamera");
> 
>  	if (cameraProperties.contains(properties::Model)) {
> -		std::string model = cameraProperties.get(properties::Model);
> +		std::string model = cameraProperties.get(properties::Model).value_or(std::string{});
>  		TIFFSetField(tif, TIFFTAG_MODEL, model.c_str());
>  		/* \todo set TIFFTAG_UNIQUECAMERAMODEL. */
>  	}
> @@ -438,7 +438,8 @@ int DNGWriter::write(const char *filename, const Camera *camera,
>  	const double eps = 1e-2;
> 
>  	if (metadata.contains(controls::ColourGains)) {
> -		Span<const float, 2> const &colourGains = metadata.get(controls::ColourGains);
> +		Span<const float, 2> const &colourGains =
> +			metadata.get(controls::ColourGains).value_or(libcamera::Span<const float, 2>({ 0, 0 }));
>  		if (colourGains[0] > eps && colourGains[1] > eps) {
>  			wbGain = Matrix3d::diag(colourGains[0], 1, colourGains[1]);
>  			neutral[0] = 1.0 / colourGains[0]; /* red */
> @@ -446,7 +447,8 @@ int DNGWriter::write(const char *filename, const Camera *camera,
>  		}
>  	}
>  	if (metadata.contains(controls::ColourCorrectionMatrix)) {
> -		Span<const float, 9> const &coeffs = metadata.get(controls::ColourCorrectionMatrix);
> +		Span<const float, 9> const &coeffs =
> +			metadata.get(controls::ColourCorrectionMatrix).value_or(Span<const float, 9>({ 0, 0, 0, 0, 0, 0, 0, 0, 0 }));
>  		Matrix3d ccmSupplied(coeffs);
>  		if (ccmSupplied.determinant() > eps)
>  			ccm = ccmSupplied;
> @@ -515,7 +517,8 @@ int DNGWriter::write(const char *filename, const Camera *camera,
>  	uint32_t whiteLevel = (1 << info->bitsPerSample) - 1;
> 
>  	if (metadata.contains(controls::SensorBlackLevels)) {
> -		Span<const int32_t, 4> levels = metadata.get(controls::SensorBlackLevels);
> +		Span<const int32_t, 4> levels =
> +			metadata.get(controls::SensorBlackLevels).value_or(Span<const int32_t, 4>({ 0, 0, 0, 0 }));
> 
>  		/*
>  		 * The black levels control is specified in R, Gr, Gb, B order.
> @@ -593,13 +596,13 @@ int DNGWriter::write(const char *filename, const Camera *camera,
>  	TIFFSetField(tif, EXIFTAG_DATETIMEDIGITIZED, strTime);
> 
>  	if (metadata.contains(controls::AnalogueGain)) {
> -		float gain = metadata.get(controls::AnalogueGain);
> +		float gain = metadata.get(controls::AnalogueGain).value_or(float{});
>  		uint16_t iso = std::min(std::max(gain * 100, 0.0f), 65535.0f);
>  		TIFFSetField(tif, EXIFTAG_ISOSPEEDRATINGS, 1, &iso);
>  	}
> 
>  	if (metadata.contains(controls::ExposureTime)) {
> -		float exposureTime = metadata.get(controls::ExposureTime) / 1e6;
> +		float exposureTime = metadata.get(controls::ExposureTime).value_or(float{}) / 1e6;
>  		TIFFSetField(tif, EXIFTAG_EXPOSURETIME, exposureTime);
>  	}
> 

-- 
Regards,

Laurent Pinchart


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