[libcamera-devel] [PATCH 1/2] libcamera: ipu3: Initialize controls in the IPA

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Fri, Jul 16, 2021 at 04:32:14PM +0200, Jacopo Mondi wrote:
> All the IPU3 Camera controls are currently initialized by the pipeline
> handler which initializes them using the camera sensor configuration and
> platform specific requirements.
> 
> However, some controls are better initialized by the IPA, which might,
> in example, cap the exposure times and frame duration to the constraints
> of its algorithms implementation.
> 
> Also, moving forward, the IPA should register controls to report its
> capabilities, in example the ability to enable/disable 3A algorithms on
> request.
> 
> Move the existing controls initialization to the IPA, by providing
> the sensor configuration and its controls to the IPU3IPA::init()
> function, which initializes controls and returns them to the pipeline
> through an output parameter.
> 
> The existing controls initialization has been copied verbatim from the
> pipeline handler to the IPA, if not a for few line breaks adjustments
> and the resulting Camera controls values are not changed .
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  include/libcamera/ipa/ipu3.mojom     |  8 ++-
>  src/ipa/ipu3/ipu3.cpp                | 71 ++++++++++++++++++--
>  src/libcamera/pipeline/ipu3/ipu3.cpp | 96 ++++++++++++----------------
>  3 files changed, 116 insertions(+), 59 deletions(-)
> 
> diff --git a/include/libcamera/ipa/ipu3.mojom b/include/libcamera/ipa/ipu3.mojom
> index 911a3a072464..eafefa8b7fe3 100644
> --- a/include/libcamera/ipa/ipu3.mojom
> +++ b/include/libcamera/ipa/ipu3.mojom
> @@ -30,6 +30,11 @@ struct IPU3Action {
>  	libcamera.ControlList controls;
>  };
>  
> +struct IPAInitInfo {
> +	libcamera.IPACameraSensorInfo sensorInfo;
> +	libcamera.ControlInfoMap sensorControls;
> +};
> +
>  struct IPAConfigInfo {
>  	libcamera.IPACameraSensorInfo sensorInfo;
>  	map<uint32, libcamera.ControlInfoMap> entityControls;
> @@ -38,7 +43,8 @@ struct IPAConfigInfo {
>  };
>  
>  interface IPAIPU3Interface {
> -	init(libcamera.IPASettings settings) => (int32 ret);
> +	init(IPAInitInfo initInfo)

By dropping IPASettings, you drop the IPA configuration file. This isn't
used by the IPA module yet, but it should be in the future, so it would
be best to keep it. One option is to add libcamera.IPASettings as a
member of IPAInitInfo.

> +		=> (int32 ret, libcamera.ControlInfoMap ipaControls);
>  	start() => (int32 ret);
>  	stop();
>  
> diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
> index 71698d36e50f..d3c69bc07bd0 100644
> --- a/src/ipa/ipu3/ipu3.cpp
> +++ b/src/ipa/ipu3/ipu3.cpp
> @@ -5,8 +5,10 @@
>   * ipu3.cpp - IPU3 Image Processing Algorithms
>   */
>  
> +#include <array>
>  #include <stdint.h>
>  #include <sys/mman.h>
> +#include <utility>
>  
>  #include <linux/intel-ipu3.h>
>  #include <linux/v4l2-controls.h>
> @@ -38,7 +40,8 @@ namespace ipa::ipu3 {
>  class IPAIPU3 : public IPAIPU3Interface
>  {
>  public:
> -	int init(const IPASettings &settings) override;
> +	int init(const IPAInitInfo &initInfo, ControlInfoMap *ipaControls) override;
> +
>  	int start() override;
>  	void stop() override {}
>  
> @@ -86,14 +89,74 @@ private:
>  	struct ipu3_uapi_grid_config bdsGrid_;
>  };
>  
> -int IPAIPU3::init(const IPASettings &settings)
> +/**
> + * Initialize the IPA module and its controls.
> + *
> + * This function receives the camera sensor information from the pipeline
> + * handler, computes the limits of the controls it handles and returns
> + * them in the \a ipaControls output parameter.
> + */
> +int IPAIPU3::init(const IPAInitInfo &initInfo, ControlInfoMap *ipaControls)
>  {
> -	camHelper_ = CameraSensorHelperFactory::create(settings.sensorModel);
> +	const IPACameraSensorInfo &sensorInfo = initInfo.sensorInfo;
> +
> +	/* Initialize the camera sensor helper. */
> +	camHelper_ = CameraSensorHelperFactory::create(sensorInfo.model);
>  	if (camHelper_ == nullptr) {
> -		LOG(IPAIPU3, Error) << "Failed to create camera sensor helper for " << settings.sensorModel;
> +		LOG(IPAIPU3, Error) << "Failed to create camera sensor helper for "
> +				    << sensorInfo.model;
>  		return -ENODEV;
>  	}
>  
> +	/* Initialize Controls. */
> +	const ControlInfoMap &sensorControls = initInfo.sensorControls;
> +	ControlInfoMap::Map controls{};
> +
> +	/*
> +	 * Compute exposure time limits.
> +	 *
> +	 * Initialize the control using the line length and pixel rate of the
> +	 * current configuration converted to microseconds. Use the
> +	 * V4L2_CID_EXPOSURE control to get exposure min, max and default and
> +	 * convert it from lines to microseconds.
> +	 */
> +	double lineDuration = sensorInfo.lineLength / (sensorInfo.pixelRate / 1e6);
> +	const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
> +	int32_t minExposure = v4l2Exposure.min().get<int32_t>() * lineDuration;
> +	int32_t maxExposure = v4l2Exposure.max().get<int32_t>() * lineDuration;
> +	int32_t defExposure = v4l2Exposure.def().get<int32_t>() * lineDuration;
> +	controls[&controls::ExposureTime] = ControlInfo(minExposure, maxExposure,
> +							defExposure);
> +
> +	/*
> +	 * Compute the frame duration limits.
> +	 *
> +	 * The frame length is computed assuming a fixed line length combined
> +	 * with the vertical frame sizes.
> +	 */
> +	const ControlInfo &v4l2HBlank = sensorControls.find(V4L2_CID_HBLANK)->second;
> +	uint32_t hblank = v4l2HBlank.def().get<int32_t>();
> +	uint32_t lineLength = sensorInfo.outputSize.width + hblank;
> +
> +	const ControlInfo &v4l2VBlank = sensorControls.find(V4L2_CID_VBLANK)->second;
> +	std::array<uint32_t, 3> frameHeights{
> +		v4l2VBlank.min().get<int32_t>() + sensorInfo.outputSize.height,
> +		v4l2VBlank.max().get<int32_t>() + sensorInfo.outputSize.height,
> +		v4l2VBlank.def().get<int32_t>() + sensorInfo.outputSize.height,
> +	};
> +
> +	std::array<int64_t, 3> frameDurations;
> +	for (unsigned int i = 0; i < frameHeights.size(); ++i) {
> +		uint64_t frameSize = lineLength * frameHeights[i];
> +		frameDurations[i] = frameSize / (sensorInfo.pixelRate / 1000000U);
> +	}
> +
> +	controls[&controls::FrameDurationLimits] = ControlInfo(frameDurations[0],
> +							       frameDurations[1],
> +							       frameDurations[2]);
> +
> +	*ipaControls = std::move(controls);
> +
>  	return 0;
>  }
>  
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index 76c3bb3d8aa9..22df9c3650af 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -88,6 +88,8 @@ public:
>  
>  	std::queue<Request *> pendingRequests_;
>  
> +	ControlInfoMap ipaControls_;
> +
>  private:
>  	void queueFrameAction(unsigned int id,
>  			      const ipa::ipu3::IPU3Action &action);
> @@ -940,7 +942,6 @@ int PipelineHandlerIPU3::initControls(IPU3CameraData *data)
>  		return ret;
>  
>  	ControlInfoMap::Map controls = IPU3Controls;
> -	const ControlInfoMap &sensorControls = sensor->controls();
>  	const std::vector<int32_t> &testPatternModes = sensor->testPatternModes();
>  	if (!testPatternModes.empty()) {
>  		std::vector<ControlValue> values;
> @@ -952,58 +953,6 @@ int PipelineHandlerIPU3::initControls(IPU3CameraData *data)
>  		controls[&controls::draft::TestPatternMode] = ControlInfo(values);
>  	}
>  
> -	/*
> -	 * Compute exposure time limits.
> -	 *
> -	 * Initialize the control using the line length and pixel rate of the
> -	 * current configuration converted to microseconds. Use the
> -	 * V4L2_CID_EXPOSURE control to get exposure min, max and default and
> -	 * convert it from lines to microseconds.
> -	 */
> -	double lineDuration = sensorInfo.lineLength
> -			    / (sensorInfo.pixelRate / 1e6);
> -	const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
> -	int32_t minExposure = v4l2Exposure.min().get<int32_t>() * lineDuration;
> -	int32_t maxExposure = v4l2Exposure.max().get<int32_t>() * lineDuration;
> -	int32_t defExposure = v4l2Exposure.def().get<int32_t>() * lineDuration;
> -
> -	/*
> -	 * \todo Report the actual exposure time, use the default for the
> -	 * moment.
> -	 */
> -	data->exposureTime_ = defExposure;
> -
> -	controls[&controls::ExposureTime] = ControlInfo(minExposure, maxExposure,
> -							defExposure);
> -
> -	/*
> -	 * Compute the frame duration limits.
> -	 *
> -	 * The frame length is computed assuming a fixed line length combined
> -	 * with the vertical frame sizes.
> -	 */
> -	const ControlInfo &v4l2HBlank = sensorControls.find(V4L2_CID_HBLANK)->second;
> -	uint32_t hblank = v4l2HBlank.def().get<int32_t>();
> -	uint32_t lineLength = sensorInfo.outputSize.width + hblank;
> -
> -	const ControlInfo &v4l2VBlank = sensorControls.find(V4L2_CID_VBLANK)->second;
> -	std::array<uint32_t, 3> frameHeights{
> -		v4l2VBlank.min().get<int32_t>() + sensorInfo.outputSize.height,
> -		v4l2VBlank.max().get<int32_t>() + sensorInfo.outputSize.height,
> -		v4l2VBlank.def().get<int32_t>() + sensorInfo.outputSize.height,
> -	};
> -
> -	std::array<int64_t, 3> frameDurations;
> -	for (unsigned int i = 0; i < frameHeights.size(); ++i) {
> -		uint64_t frameSize = lineLength * frameHeights[i];
> -		frameDurations[i] = frameSize / (sensorInfo.pixelRate / 1000000U);
> -	}
> -
> -	controls[&controls::FrameDurationLimits] =
> -		ControlInfo(frameDurations[0],
> -			    frameDurations[1],
> -			    frameDurations[2]);
> -
>  	/*
>  	 * Compute the scaler crop limits.
>  	 *
> @@ -1057,6 +1006,10 @@ int PipelineHandlerIPU3::initControls(IPU3CameraData *data)
>  
>  	controls[&controls::ScalerCrop] = ControlInfo(minCrop, maxCrop, maxCrop);
>  
> +	/* Add the IPA registered controls to list of camera controls. */
> +	for (const auto &ipaControl : data->ipaControls_)
> +		controls[ipaControl.first] = ipaControl.second;

It would be nice to use merge(), but ControlInfoMap inherits from
std::unordered_map<> with a private access specifier :-S Yet another
opportunity to improve the controls API.

> +
>  	data->controlInfo_ = std::move(controls);
>  
>  	return 0;
> @@ -1208,13 +1161,48 @@ int IPU3CameraData::loadIPA()
>  
>  	ipa_->queueFrameAction.connect(this, &IPU3CameraData::queueFrameAction);
>  
> +	/*
> +	 * Pass the sensor info the the IPA to initialize controls.

s/the the/to the/

> +	 *
> +	 * \todo The limits of the registered controls depend on the current
> +	 * sensor configuration. Initialize the sensor using its resolution as
> +	 * its initial configuration and use it to compute the controls limits
> +	 * in the IPA.

Could you rewrite this to explain what would need to be done to fix the
problem, instead of only describing the current implementation ? I'm
sure we understand it correctly now, but that may not be the case when
we'll tackle this todo item, or if someone less familiar with the issue
reads the comment.

> +	 */
>  	CameraSensor *sensor = cio2_.sensor();
> -	int ret = ipa_->init(IPASettings{ "", sensor->model() });
> +	V4L2SubdeviceFormat sensorFormat = {};
> +	sensorFormat.size = sensor->resolution();
> +	int ret = sensor->setFormat(&sensorFormat);
> +	if (ret)
> +		return ret;
> +
> +	IPACameraSensorInfo sensorInfo{};
> +	ret = sensor->sensorInfo(&sensorInfo);
> +	if (ret)
> +		return ret;
> +
> +	ipa::ipu3::IPAInitInfo initInfo{
> +		sensorInfo,
> +		sensor->controls(),
> +	};
> +	ipaControls_ = {};

I think this line could be dropped, ipaControls_ is default-initialized
when IPU3CameraData is constructed, and loadIPA() is called once only.

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +	ret = ipa_->init(initInfo, &ipaControls_);
>  	if (ret) {
>  		LOG(IPU3, Error) << "Failed to initialise the IPU3 IPA";
>  		return ret;
>  	}
>  
> +	/*
> +	 * \todo Report the actual exposure time, use the default for the
> +	 * moment.
> +	 */
> +	const auto exposureInfo = ipaControls_.find(&controls::ExposureTime);
> +	if (exposureInfo == ipaControls_.end()) {
> +		LOG(IPU3, Error) << "Exposure control not initializaed by the IPA";
> +		return -EINVAL;
> +	}
> +	exposureTime_ = exposureInfo->second.def().get<int32_t>();
> +
>  	return 0;
>  }
>  

-- 
Regards,

Laurent Pinchart