[v7,4/4] libcamera: rkisp1: Plumb the dw100 dewarper as V4L2M2M converter

21172 diff mbox series

Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
handler. If the dewarper is found, it is instantiated and buffers are
exported from it, instead of RkISP1Path. Internal buffers are allocated
for the RkISP1Path in case where dewarper is going to be used.

The RKISP1 pipeline handler now supports scaler crop control through
the converter. Register the ScalerCrop control for the cameras created
in the RKISP1 pipeline handler.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
---
 src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
 1 file changed, 176 insertions(+), 7 deletions(-)

Hi Umang,

Thank you for the patch. 

On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
> Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
> handler. If the dewarper is found, it is instantiated and buffers are
> exported from it, instead of RkISP1Path. Internal buffers are allocated
> for the RkISP1Path in case where dewarper is going to be used.
> 
> The RKISP1 pipeline handler now supports scaler crop control through
> the converter. Register the ScalerCrop control for the cameras created
> in the RKISP1 pipeline handler.
> 
> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> ---
>  src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
>  1 file changed, 176 insertions(+), 7 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> index 651258e3..0a794d63 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> @@ -6,10 +6,12 @@
>   */
>  
>  #include <algorithm>
> +#include <map>
>  #include <memory>
>  #include <numeric>
>  #include <optional>
>  #include <queue>
> +#include <vector>
>  
>  #include <linux/media-bus-format.h>
>  #include <linux/rkisp1-config.h>
> @@ -32,6 +34,7 @@
>  
>  #include "libcamera/internal/camera.h"
>  #include "libcamera/internal/camera_sensor.h"
> +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
>  #include "libcamera/internal/delayed_controls.h"
>  #include "libcamera/internal/device_enumerator.h"
>  #include "libcamera/internal/framebuffer.h"
> @@ -180,6 +183,7 @@ private:
>  	void bufferReady(FrameBuffer *buffer);
>  	void paramReady(FrameBuffer *buffer);
>  	void statReady(FrameBuffer *buffer);
> +	void dewarpBufferReady(FrameBuffer *buffer);
>  	void frameStart(uint32_t sequence);
>  
>  	int allocateBuffers(Camera *camera);
> @@ -199,6 +203,15 @@ private:
>  	RkISP1MainPath mainPath_;
>  	RkISP1SelfPath selfPath_;
>  
> +	std::unique_ptr<V4L2M2MConverter> dewarper_;
> +	bool useDewarper_;
> +
> +	std::optional<Rectangle> activeCrop_;
> +
> +	/* Internal buffers used when dewarper is being used */
> +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
> +	std::queue<FrameBuffer *> availableMainPathBuffers_;
> +
>  	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
>  	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
>  	std::queue<FrameBuffer *> availableParamBuffers_;
> @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>  
>  	FrameBuffer *paramBuffer = nullptr;
>  	FrameBuffer *statBuffer = nullptr;
> +	FrameBuffer *mainPathBuffer = nullptr;
> +	FrameBuffer *selfPathBuffer = nullptr;
>  
>  	if (!isRaw) {
>  		if (pipe_->availableParamBuffers_.empty()) {
> @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>  
>  		statBuffer = pipe_->availableStatBuffers_.front();
>  		pipe_->availableStatBuffers_.pop();
> +
> +		if (pipe_->useDewarper_) {
> +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
> +			pipe_->availableMainPathBuffers_.pop();
> +		}
>  	}
>  
> -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
> +	if (!mainPathBuffer)
> +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>  
>  	RkISP1FrameInfo *info = new RkISP1FrameInfo;
>  
> @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
>  
>  	pipe_->availableParamBuffers_.push(info->paramBuffer);
>  	pipe_->availableStatBuffers_.push(info->statBuffer);
> +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>  
>  	frameInfo_.erase(info->frame);
>  
> @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
>  
>  		pipe_->availableParamBuffers_.push(info->paramBuffer);
>  		pipe_->availableStatBuffers_.push(info->statBuffer);
> +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>  
>  		delete info;
>  	}
> @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
>   */
>  
>  PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
> -	: PipelineHandler(manager), hasSelfPath_(true)
> +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
>  {
>  }
>  
> @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
>  		<< " crop " << rect;
>  
>  	std::map<unsigned int, IPAStream> streamConfig;
> +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
>  
>  	for (const StreamConfiguration &cfg : *config) {
>  		if (cfg.stream() == &data->mainPathStream_) {
>  			ret = mainPath_.configure(cfg, format);
>  			streamConfig[0] = IPAStream(cfg.pixelFormat,
>  						    cfg.size);
> +			/* Configure dewarp */
> +			if (dewarper_ && !isRaw_) {
> +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
> +				ret = dewarper_->configure(cfg, outputCfgs);
> +				useDewarper_ = ret ? false : true;
> +			}
>  		} else if (hasSelfPath_) {
>  			ret = selfPath_.configure(cfg, format);
>  			streamConfig[1] = IPAStream(cfg.pixelFormat,
> @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
>  	RkISP1CameraData *data = cameraData(camera);
>  	unsigned int count = stream->configuration().bufferCount;
>  
> -	if (stream == &data->mainPathStream_)
> -		return mainPath_.exportBuffers(count, buffers);
> -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
> +	if (stream == &data->mainPathStream_) {
> +		/*
> +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
> +		 * It has mainpath and no self path. Hence, export buffers from
> +		 * dewarper just for the main path stream, for now.
> +		 */
> +		if (useDewarper_)
> +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
> +		else
> +			return mainPath_.exportBuffers(count, buffers);
> +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
>  		return selfPath_.exportBuffers(count, buffers);
> +	}
>  
>  	return -EINVAL;
>  }
> @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>  		ret = stat_->allocateBuffers(maxCount, &statBuffers_);

Is there a way for the user to prevent usage of the dewarper? It
increases latency and doubles the required buffers. Now that I write
about it. To configure actual lens dewarping I envision something like a
"dewarp" algorithm in the tuning file. Maybe that is the best place for
that decision...

>  		if (ret < 0)
>  			goto error;
> +
> +		/* If the dewarper is being used, allocate internal buffers for ISP. */
> +		if (useDewarper_) {
> +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
> +			if (ret < 0)
> +				goto error;
> +
> +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
> +				availableMainPathBuffers_.push(buffer.get());
> +		}
>  	}
>  
>  	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
> @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>  error:
>  	paramBuffers_.clear();
>  	statBuffers_.clear();
> +	mainPathBuffers_.clear();
>  
>  	return ret;
>  }
> @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>  	while (!availableParamBuffers_.empty())
>  		availableParamBuffers_.pop();
>  
> +	while (!availableMainPathBuffers_.empty())
> +		availableMainPathBuffers_.pop();
> +
>  	paramBuffers_.clear();
>  	statBuffers_.clear();
> +	mainPathBuffers_.clear();
>  
>  	std::vector<unsigned int> ids;
>  	for (IPABuffer &ipabuf : data->ipaBuffers_)
> @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
>  			return ret;
>  		}
>  		actions += [&]() { stat_->streamOff(); };
> +
> +		if (useDewarper_) {
> +			ret = dewarper_->start();
> +			if (ret) {
> +				LOG(RkISP1, Error) << "Failed to start dewarper";
> +				return ret;
> +			}
> +		}
> +		actions += [&]() { dewarper_->stop(); };
>  	}
>  
>  	if (data->mainPath_->isEnabled()) {
> @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
>  		if (ret)
>  			LOG(RkISP1, Warning)
>  				<< "Failed to stop parameters for " << camera->id();
> +
> +		if (useDewarper_)
> +			dewarper_->stop();
>  	}
>  
>  	ASSERT(data->queuedRequests_.empty());
> @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
>  {
>  	ControlInfoMap::Map controls;
>  
> +	if (dewarper_) {
> +		std::pair<Rectangle, Rectangle> cropLimits =
> +			dewarper_->inputCropBounds(&data->mainPathStream_);
> +
> +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
> +							      cropLimits.second,
> +							      cropLimits.second);
> +		activeCrop_ = cropLimits.second;
> +	}
> +

I'm a bit uncertain here. The current dewarper kernel driver produces
quite unexpected and difficult to explain results (modified crop
rectangle, changed pixel aspect ratio). So to me it feels like we
shouldn't expose that hardware control directly to the user, but do an
internal implementation (based on the same libcamera control). Could we
split just the logic that adds the control into a separate patch?

Another approach would be to merge it in and improve later. But then we
might break the interface for users of the feature... I lean towards
splitting the control and merging the rest. In that case we should
disable the dewarper by default, as the user has no added benefit
without the control. Still I think all the plumbing should definitely
go in.

>  	/* Add the IPA registered controls to list of camera controls. */
>  	for (const auto &ipaControl : data->ipaControls_)
>  		controls[ipaControl.first] = ipaControl.second;
> @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
>  	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
>  	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
>  
> +	/* If dewarper is present, create its instance. */
> +	DeviceMatch dwp("dw100");
> +	dwp.add("dw100-source");
> +	dwp.add("dw100-sink");
> +
> +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
> +	if (dwpMediaDevice) {
> +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
> +		if (dewarper_->isValid()) {
> +			dewarper_->outputBufferReady.connect(
> +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
> +
> +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();
> +		} else {
> +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
> +					     << " but invalid";
> +			dewarper_.reset();
> +		}
> +	}
> +
>  	/*
>  	 * Enumerate all sensors connected to the ISP and create one
>  	 * camera instance for each of them.
> @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>  		return;
>  
>  	const FrameMetadata &metadata = buffer->metadata();
> -	Request *request = buffer->request();
> +	Request *request = info->request;
>  
>  	if (metadata.status != FrameMetadata::FrameCancelled) {
>  		/*
> @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>  			info->metadataProcessed = true;
>  	}
>  
> +	if (!useDewarper_) {
> +		completeBuffer(request, buffer);
> +		tryCompleteRequest(info);
> +
> +		return;
> +	}
> +
> +	/* Do not queue cancelled frames to dewarper. */
> +	if (metadata.status == FrameMetadata::FrameCancelled) {
> +		/*
> +		 * i.MX8MP is the only known platform with dewarper. It has
> +		 * no self path. Hence, only main path buffer completion is
> +		 * required.
> +		 *
> +		 * Also, we cannot completeBuffer(request, buffer) as buffer
> +		 * here, is an internal buffer (between ISP and dewarper) and
> +		 * is not associated to the any specific request. The request
> +		 * buffer associated with main path stream is the one that
> +		 * is required to be completed (not the internal buffer).
> +		 */
> +		for (auto it : request->buffers()) {
> +			if (it.first == &data->mainPathStream_)
> +				completeBuffer(request, it.second);
> +		}
> +
> +		tryCompleteRequest(info);
> +		return;
> +	}
> +
> +	/* Handle scaler crop control. */
> +	const auto &crop = request->controls().get(controls::ScalerCrop);
> +	if (crop) {
> +		Rectangle appliedRect = crop.value();
> +
> +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
> +						  &appliedRect);
> +		if (!ret && appliedRect != crop.value()) {
> +			/*
> +			 * If the rectangle is changed by setInputCrop on the
> +			 * dewarper, log a debug message and cache the actual
> +			 * applied rectangle for metadata reporting.
> +			 */
> +			LOG(RkISP1, Debug)
> +				<< "Applied rectangle " << appliedRect.toString()
> +				<< " differs from requested " << crop.value().toString();
> +		}
> +
> +		activeCrop_ = appliedRect;
> +	}
> +
> +	/*
> +	 * Queue input and output buffers to the dewarper. The output
> +	 * buffers for the dewarper are the buffers of the request, supplied
> +	 * by the application.
> +	 */
> +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
> +	if (ret < 0)
> +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
> +				   << strerror(-ret);
> +}
> +
> +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
> +{
> +	ASSERT(activeCamera_);
> +	RkISP1CameraData *data = cameraData(activeCamera_);
> +	Request *request = buffer->request();
> +
> +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
> +	if (!info)
> +		return;
> +
> +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());

I couldn't easily see if there are cases where more than one buffer are
queued to the dewarper. In that case the activeCrop_ could be the one
applied to the next frame. If it is ensured that that is not the case it
might be worth a comment.

Best regards,
Stefan

> +
>  	completeBuffer(request, buffer);
>  	tryCompleteRequest(info);
>  }
> -- 
> 2.45.0
>

Hi Stefan,

On 25/09/24 1:20 pm, Stefan Klug wrote:
> Hi Umang,
>
> Thank you for the patch.
>
> On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
>> Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
>> handler. If the dewarper is found, it is instantiated and buffers are
>> exported from it, instead of RkISP1Path. Internal buffers are allocated
>> for the RkISP1Path in case where dewarper is going to be used.
>>
>> The RKISP1 pipeline handler now supports scaler crop control through
>> the converter. Register the ScalerCrop control for the cameras created
>> in the RKISP1 pipeline handler.
>>
>> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
>> ---
>>   src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
>>   1 file changed, 176 insertions(+), 7 deletions(-)
>>
>> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>> index 651258e3..0a794d63 100644
>> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>> @@ -6,10 +6,12 @@
>>    */
>>   
>>   #include <algorithm>
>> +#include <map>
>>   #include <memory>
>>   #include <numeric>
>>   #include <optional>
>>   #include <queue>
>> +#include <vector>
>>   
>>   #include <linux/media-bus-format.h>
>>   #include <linux/rkisp1-config.h>
>> @@ -32,6 +34,7 @@
>>   
>>   #include "libcamera/internal/camera.h"
>>   #include "libcamera/internal/camera_sensor.h"
>> +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
>>   #include "libcamera/internal/delayed_controls.h"
>>   #include "libcamera/internal/device_enumerator.h"
>>   #include "libcamera/internal/framebuffer.h"
>> @@ -180,6 +183,7 @@ private:
>>   	void bufferReady(FrameBuffer *buffer);
>>   	void paramReady(FrameBuffer *buffer);
>>   	void statReady(FrameBuffer *buffer);
>> +	void dewarpBufferReady(FrameBuffer *buffer);
>>   	void frameStart(uint32_t sequence);
>>   
>>   	int allocateBuffers(Camera *camera);
>> @@ -199,6 +203,15 @@ private:
>>   	RkISP1MainPath mainPath_;
>>   	RkISP1SelfPath selfPath_;
>>   
>> +	std::unique_ptr<V4L2M2MConverter> dewarper_;
>> +	bool useDewarper_;
>> +
>> +	std::optional<Rectangle> activeCrop_;
>> +
>> +	/* Internal buffers used when dewarper is being used */
>> +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
>> +	std::queue<FrameBuffer *> availableMainPathBuffers_;
>> +
>>   	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
>>   	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
>>   	std::queue<FrameBuffer *> availableParamBuffers_;
>> @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>>   
>>   	FrameBuffer *paramBuffer = nullptr;
>>   	FrameBuffer *statBuffer = nullptr;
>> +	FrameBuffer *mainPathBuffer = nullptr;
>> +	FrameBuffer *selfPathBuffer = nullptr;
>>   
>>   	if (!isRaw) {
>>   		if (pipe_->availableParamBuffers_.empty()) {
>> @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>>   
>>   		statBuffer = pipe_->availableStatBuffers_.front();
>>   		pipe_->availableStatBuffers_.pop();
>> +
>> +		if (pipe_->useDewarper_) {
>> +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
>> +			pipe_->availableMainPathBuffers_.pop();
>> +		}
>>   	}
>>   
>> -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
>> -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>> +	if (!mainPathBuffer)
>> +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
>> +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>>   
>>   	RkISP1FrameInfo *info = new RkISP1FrameInfo;
>>   
>> @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
>>   
>>   	pipe_->availableParamBuffers_.push(info->paramBuffer);
>>   	pipe_->availableStatBuffers_.push(info->statBuffer);
>> +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>>   
>>   	frameInfo_.erase(info->frame);
>>   
>> @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
>>   
>>   		pipe_->availableParamBuffers_.push(info->paramBuffer);
>>   		pipe_->availableStatBuffers_.push(info->statBuffer);
>> +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>>   
>>   		delete info;
>>   	}
>> @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
>>    */
>>   
>>   PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
>> -	: PipelineHandler(manager), hasSelfPath_(true)
>> +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
>>   {
>>   }
>>   
>> @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
>>   		<< " crop " << rect;
>>   
>>   	std::map<unsigned int, IPAStream> streamConfig;
>> +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
>>   
>>   	for (const StreamConfiguration &cfg : *config) {
>>   		if (cfg.stream() == &data->mainPathStream_) {
>>   			ret = mainPath_.configure(cfg, format);
>>   			streamConfig[0] = IPAStream(cfg.pixelFormat,
>>   						    cfg.size);
>> +			/* Configure dewarp */
>> +			if (dewarper_ && !isRaw_) {
>> +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
>> +				ret = dewarper_->configure(cfg, outputCfgs);
>> +				useDewarper_ = ret ? false : true;
>> +			}
>>   		} else if (hasSelfPath_) {
>>   			ret = selfPath_.configure(cfg, format);
>>   			streamConfig[1] = IPAStream(cfg.pixelFormat,
>> @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
>>   	RkISP1CameraData *data = cameraData(camera);
>>   	unsigned int count = stream->configuration().bufferCount;
>>   
>> -	if (stream == &data->mainPathStream_)
>> -		return mainPath_.exportBuffers(count, buffers);
>> -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
>> +	if (stream == &data->mainPathStream_) {
>> +		/*
>> +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
>> +		 * It has mainpath and no self path. Hence, export buffers from
>> +		 * dewarper just for the main path stream, for now.
>> +		 */
>> +		if (useDewarper_)
>> +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
>> +		else
>> +			return mainPath_.exportBuffers(count, buffers);
>> +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
>>   		return selfPath_.exportBuffers(count, buffers);
>> +	}
>>   
>>   	return -EINVAL;
>>   }
>> @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>>   		ret = stat_->allocateBuffers(maxCount, &statBuffers_);
> Is there a way for the user to prevent usage of the dewarper? It
> increases latency and doubles the required buffers. Now that I write
> about it. To configure actual lens dewarping I envision something like a
> "dewarp" algorithm in the tuning file. Maybe that is the best place for
> that decision...

I think somewhere in the previous interations, we decided that if the 
dewarper is present, it should be discovered and used. At that point, we 
failed to justify any use cases, where a user might have to disable the 
dewarper 'intentionally'.

If there is use case, we can surely allow disabling the dewarper (and 
shouldn't be a tedious patch on top, I believe). But, The justification 
has to be there.

>
>>   		if (ret < 0)
>>   			goto error;
>> +
>> +		/* If the dewarper is being used, allocate internal buffers for ISP. */
>> +		if (useDewarper_) {
>> +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
>> +			if (ret < 0)
>> +				goto error;
>> +
>> +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
>> +				availableMainPathBuffers_.push(buffer.get());
>> +		}
>>   	}
>>   
>>   	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
>> @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>>   error:
>>   	paramBuffers_.clear();
>>   	statBuffers_.clear();
>> +	mainPathBuffers_.clear();
>>   
>>   	return ret;
>>   }
>> @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>>   	while (!availableParamBuffers_.empty())
>>   		availableParamBuffers_.pop();
>>   
>> +	while (!availableMainPathBuffers_.empty())
>> +		availableMainPathBuffers_.pop();
>> +
>>   	paramBuffers_.clear();
>>   	statBuffers_.clear();
>> +	mainPathBuffers_.clear();
>>   
>>   	std::vector<unsigned int> ids;
>>   	for (IPABuffer &ipabuf : data->ipaBuffers_)
>> @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
>>   			return ret;
>>   		}
>>   		actions += [&]() { stat_->streamOff(); };
>> +
>> +		if (useDewarper_) {
>> +			ret = dewarper_->start();
>> +			if (ret) {
>> +				LOG(RkISP1, Error) << "Failed to start dewarper";
>> +				return ret;
>> +			}
>> +		}
>> +		actions += [&]() { dewarper_->stop(); };
>>   	}
>>   
>>   	if (data->mainPath_->isEnabled()) {
>> @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
>>   		if (ret)
>>   			LOG(RkISP1, Warning)
>>   				<< "Failed to stop parameters for " << camera->id();
>> +
>> +		if (useDewarper_)
>> +			dewarper_->stop();
>>   	}
>>   
>>   	ASSERT(data->queuedRequests_.empty());
>> @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
>>   {
>>   	ControlInfoMap::Map controls;
>>   
>> +	if (dewarper_) {
>> +		std::pair<Rectangle, Rectangle> cropLimits =
>> +			dewarper_->inputCropBounds(&data->mainPathStream_);
>> +
>> +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
>> +							      cropLimits.second,
>> +							      cropLimits.second);
>> +		activeCrop_ = cropLimits.second;
>> +	}
>> +
> I'm a bit uncertain here. The current dewarper kernel driver produces
> quite unexpected and difficult to explain results (modified crop
> rectangle, changed pixel aspect ratio). So to me it feels like we
> shouldn't expose that hardware control directly to the user, but do an
> internal implementation (based on the same libcamera control). Could we
> split just the logic that adds the control into a separate patch?

I don't understand internal implementation based on same libcamera 
control? How would that look like?

So, you mean to say, we don't feed any scaler crop rectangles from 
application, but do it internally ?
>
> Another approach would be to merge it in and improve later. But then we
> might break the interface for users of the feature... I lean towards
> splitting the control and merging the rest. In that case we should
> disable the dewarper by default, as the user has no added benefit
> without the control. Still I think all the plumbing should definitely
> go in.

I don't foresee breaking the interface for users. But there can be 
improvements on top of this (for e.g. mapping the V4L2 Selection flags) 
and letting the application control that via an interface.

https://docs.kernel.org/userspace-api/media/v4l/v4l2-selection-flags.html

>
>>   	/* Add the IPA registered controls to list of camera controls. */
>>   	for (const auto &ipaControl : data->ipaControls_)
>>   		controls[ipaControl.first] = ipaControl.second;
>> @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
>>   	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
>>   	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
>>   
>> +	/* If dewarper is present, create its instance. */
>> +	DeviceMatch dwp("dw100");
>> +	dwp.add("dw100-source");
>> +	dwp.add("dw100-sink");
>> +
>> +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
>> +	if (dwpMediaDevice) {
>> +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
>> +		if (dewarper_->isValid()) {
>> +			dewarper_->outputBufferReady.connect(
>> +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
>> +
>> +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();
>> +		} else {
>> +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
>> +					     << " but invalid";
>> +			dewarper_.reset();
>> +		}
>> +	}
>> +
>>   	/*
>>   	 * Enumerate all sensors connected to the ISP and create one
>>   	 * camera instance for each of them.
>> @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>>   		return;
>>   
>>   	const FrameMetadata &metadata = buffer->metadata();
>> -	Request *request = buffer->request();
>> +	Request *request = info->request;
>>   
>>   	if (metadata.status != FrameMetadata::FrameCancelled) {
>>   		/*
>> @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>>   			info->metadataProcessed = true;
>>   	}
>>   
>> +	if (!useDewarper_) {
>> +		completeBuffer(request, buffer);
>> +		tryCompleteRequest(info);
>> +
>> +		return;
>> +	}
>> +
>> +	/* Do not queue cancelled frames to dewarper. */
>> +	if (metadata.status == FrameMetadata::FrameCancelled) {
>> +		/*
>> +		 * i.MX8MP is the only known platform with dewarper. It has
>> +		 * no self path. Hence, only main path buffer completion is
>> +		 * required.
>> +		 *
>> +		 * Also, we cannot completeBuffer(request, buffer) as buffer
>> +		 * here, is an internal buffer (between ISP and dewarper) and
>> +		 * is not associated to the any specific request. The request
>> +		 * buffer associated with main path stream is the one that
>> +		 * is required to be completed (not the internal buffer).
>> +		 */
>> +		for (auto it : request->buffers()) {
>> +			if (it.first == &data->mainPathStream_)
>> +				completeBuffer(request, it.second);
>> +		}
>> +
>> +		tryCompleteRequest(info);
>> +		return;
>> +	}
>> +
>> +	/* Handle scaler crop control. */
>> +	const auto &crop = request->controls().get(controls::ScalerCrop);
>> +	if (crop) {
>> +		Rectangle appliedRect = crop.value();
>> +
>> +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
>> +						  &appliedRect);
>> +		if (!ret && appliedRect != crop.value()) {
>> +			/*
>> +			 * If the rectangle is changed by setInputCrop on the
>> +			 * dewarper, log a debug message and cache the actual
>> +			 * applied rectangle for metadata reporting.
>> +			 */
>> +			LOG(RkISP1, Debug)
>> +				<< "Applied rectangle " << appliedRect.toString()
>> +				<< " differs from requested " << crop.value().toString();
>> +		}
>> +
>> +		activeCrop_ = appliedRect;
>> +	}
>> +
>> +	/*
>> +	 * Queue input and output buffers to the dewarper. The output
>> +	 * buffers for the dewarper are the buffers of the request, supplied
>> +	 * by the application.
>> +	 */
>> +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
>> +	if (ret < 0)
>> +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
>> +				   << strerror(-ret);
>> +}
>> +
>> +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
>> +{
>> +	ASSERT(activeCamera_);
>> +	RkISP1CameraData *data = cameraData(activeCamera_);
>> +	Request *request = buffer->request();
>> +
>> +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
>> +	if (!info)
>> +		return;
>> +
>> +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());
> I couldn't easily see if there are cases where more than one buffer are
> queued to the dewarper. In that case the activeCrop_ could be the one
> applied to the next frame. If it is ensured that that is not the case it
> might be worth a comment.
>
> Best regards,
> Stefan
>
>> +
>>   	completeBuffer(request, buffer);
>>   	tryCompleteRequest(info);
>>   }
>> -- 
>> 2.45.0
>>

Hi Umang,

Thank you for the patch.

On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
> Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
> handler. If the dewarper is found, it is instantiated and buffers are
> exported from it, instead of RkISP1Path. Internal buffers are allocated
> for the RkISP1Path in case where dewarper is going to be used.
> 
> The RKISP1 pipeline handler now supports scaler crop control through
> the converter. Register the ScalerCrop control for the cameras created
> in the RKISP1 pipeline handler.
> 
> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> ---
>  src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
>  1 file changed, 176 insertions(+), 7 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> index 651258e3..0a794d63 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> @@ -6,10 +6,12 @@
>   */
>  
>  #include <algorithm>
> +#include <map>
>  #include <memory>
>  #include <numeric>
>  #include <optional>
>  #include <queue>
> +#include <vector>
>  
>  #include <linux/media-bus-format.h>
>  #include <linux/rkisp1-config.h>
> @@ -32,6 +34,7 @@
>  
>  #include "libcamera/internal/camera.h"
>  #include "libcamera/internal/camera_sensor.h"
> +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
>  #include "libcamera/internal/delayed_controls.h"
>  #include "libcamera/internal/device_enumerator.h"
>  #include "libcamera/internal/framebuffer.h"
> @@ -180,6 +183,7 @@ private:
>  	void bufferReady(FrameBuffer *buffer);
>  	void paramReady(FrameBuffer *buffer);
>  	void statReady(FrameBuffer *buffer);
> +	void dewarpBufferReady(FrameBuffer *buffer);
>  	void frameStart(uint32_t sequence);
>  
>  	int allocateBuffers(Camera *camera);
> @@ -199,6 +203,15 @@ private:
>  	RkISP1MainPath mainPath_;
>  	RkISP1SelfPath selfPath_;
>  
> +	std::unique_ptr<V4L2M2MConverter> dewarper_;
> +	bool useDewarper_;
> +
> +	std::optional<Rectangle> activeCrop_;
> +
> +	/* Internal buffers used when dewarper is being used */
> +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
> +	std::queue<FrameBuffer *> availableMainPathBuffers_;
> +
>  	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
>  	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
>  	std::queue<FrameBuffer *> availableParamBuffers_;
> @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>  
>  	FrameBuffer *paramBuffer = nullptr;
>  	FrameBuffer *statBuffer = nullptr;
> +	FrameBuffer *mainPathBuffer = nullptr;
> +	FrameBuffer *selfPathBuffer = nullptr;
>  
>  	if (!isRaw) {
>  		if (pipe_->availableParamBuffers_.empty()) {
> @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>  
>  		statBuffer = pipe_->availableStatBuffers_.front();
>  		pipe_->availableStatBuffers_.pop();
> +
> +		if (pipe_->useDewarper_) {
> +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
> +			pipe_->availableMainPathBuffers_.pop();
> +		}
>  	}
>  
> -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
> +	if (!mainPathBuffer)
> +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>  
>  	RkISP1FrameInfo *info = new RkISP1FrameInfo;
>  
> @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
>  
>  	pipe_->availableParamBuffers_.push(info->paramBuffer);
>  	pipe_->availableStatBuffers_.push(info->statBuffer);
> +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>  
>  	frameInfo_.erase(info->frame);
>  
> @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
>  
>  		pipe_->availableParamBuffers_.push(info->paramBuffer);
>  		pipe_->availableStatBuffers_.push(info->statBuffer);
> +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>  
>  		delete info;
>  	}
> @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
>   */
>  
>  PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
> -	: PipelineHandler(manager), hasSelfPath_(true)
> +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
>  {
>  }
>  
> @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
>  		<< " crop " << rect;
>  
>  	std::map<unsigned int, IPAStream> streamConfig;
> +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
>  
>  	for (const StreamConfiguration &cfg : *config) {
>  		if (cfg.stream() == &data->mainPathStream_) {
>  			ret = mainPath_.configure(cfg, format);
>  			streamConfig[0] = IPAStream(cfg.pixelFormat,
>  						    cfg.size);
> +			/* Configure dewarp */
> +			if (dewarper_ && !isRaw_) {
> +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
> +				ret = dewarper_->configure(cfg, outputCfgs);
> +				useDewarper_ = ret ? false : true;
> +			}
>  		} else if (hasSelfPath_) {
>  			ret = selfPath_.configure(cfg, format);
>  			streamConfig[1] = IPAStream(cfg.pixelFormat,
> @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
>  	RkISP1CameraData *data = cameraData(camera);
>  	unsigned int count = stream->configuration().bufferCount;
>  
> -	if (stream == &data->mainPathStream_)
> -		return mainPath_.exportBuffers(count, buffers);
> -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
> +	if (stream == &data->mainPathStream_) {
> +		/*
> +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
> +		 * It has mainpath and no self path. Hence, export buffers from
> +		 * dewarper just for the main path stream, for now.
> +		 */
> +		if (useDewarper_)
> +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
> +		else
> +			return mainPath_.exportBuffers(count, buffers);
> +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
>  		return selfPath_.exportBuffers(count, buffers);
> +	}
>  
>  	return -EINVAL;
>  }
> @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>  		ret = stat_->allocateBuffers(maxCount, &statBuffers_);
>  		if (ret < 0)
>  			goto error;
> +
> +		/* If the dewarper is being used, allocate internal buffers for ISP. */
> +		if (useDewarper_) {
> +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
> +			if (ret < 0)
> +				goto error;
> +
> +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
> +				availableMainPathBuffers_.push(buffer.get());
> +		}
>  	}
>  
>  	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
> @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>  error:
>  	paramBuffers_.clear();
>  	statBuffers_.clear();
> +	mainPathBuffers_.clear();
>  
>  	return ret;
>  }
> @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>  	while (!availableParamBuffers_.empty())
>  		availableParamBuffers_.pop();
>  
> +	while (!availableMainPathBuffers_.empty())
> +		availableMainPathBuffers_.pop();
> +
>  	paramBuffers_.clear();
>  	statBuffers_.clear();
> +	mainPathBuffers_.clear();
>  
>  	std::vector<unsigned int> ids;
>  	for (IPABuffer &ipabuf : data->ipaBuffers_)
> @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
>  			return ret;
>  		}
>  		actions += [&]() { stat_->streamOff(); };
> +
> +		if (useDewarper_) {
> +			ret = dewarper_->start();
> +			if (ret) {
> +				LOG(RkISP1, Error) << "Failed to start dewarper";
> +				return ret;
> +			}
> +		}
> +		actions += [&]() { dewarper_->stop(); };
>  	}
>  
>  	if (data->mainPath_->isEnabled()) {
> @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
>  		if (ret)
>  			LOG(RkISP1, Warning)
>  				<< "Failed to stop parameters for " << camera->id();
> +
> +		if (useDewarper_)
> +			dewarper_->stop();
>  	}
>  
>  	ASSERT(data->queuedRequests_.empty());
> @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
>  {
>  	ControlInfoMap::Map controls;
>  
> +	if (dewarper_) {
> +		std::pair<Rectangle, Rectangle> cropLimits =
> +			dewarper_->inputCropBounds(&data->mainPathStream_);
> +
> +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
> +							      cropLimits.second,
> +							      cropLimits.second);
> +		activeCrop_ = cropLimits.second;
> +	}
> +
>  	/* Add the IPA registered controls to list of camera controls. */
>  	for (const auto &ipaControl : data->ipaControls_)
>  		controls[ipaControl.first] = ipaControl.second;
> @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
>  	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
>  	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
>  
> +	/* If dewarper is present, create its instance. */
> +	DeviceMatch dwp("dw100");
> +	dwp.add("dw100-source");
> +	dwp.add("dw100-sink");
> +
> +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
> +	if (dwpMediaDevice) {
> +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
> +		if (dewarper_->isValid()) {
> +			dewarper_->outputBufferReady.connect(
> +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
> +
> +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();

			LOG(RkISP1, Info)
				<< "Using DW100 dewarper " << dewarper_->deviceNode();
			
> +		} else {
> +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
> +					     << " but invalid";

			LOG(RkISP1, Warning)
				<< "Found DW100 dewarper " << dewarper_->deviceNode()
				<< " but invalid";

> +			dewarper_.reset();
> +		}
> +	}
> +
>  	/*
>  	 * Enumerate all sensors connected to the ISP and create one
>  	 * camera instance for each of them.
> @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>  		return;
>  
>  	const FrameMetadata &metadata = buffer->metadata();
> -	Request *request = buffer->request();
> +	Request *request = info->request;
>  
>  	if (metadata.status != FrameMetadata::FrameCancelled) {
>  		/*
> @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>  			info->metadataProcessed = true;
>  	}
>  
> +	if (!useDewarper_) {
> +		completeBuffer(request, buffer);
> +		tryCompleteRequest(info);
> +
> +		return;
> +	}
> +
> +	/* Do not queue cancelled frames to dewarper. */
> +	if (metadata.status == FrameMetadata::FrameCancelled) {
> +		/*
> +		 * i.MX8MP is the only known platform with dewarper. It has
> +		 * no self path. Hence, only main path buffer completion is
> +		 * required.
> +		 *
> +		 * Also, we cannot completeBuffer(request, buffer) as buffer
> +		 * here, is an internal buffer (between ISP and dewarper) and
> +		 * is not associated to the any specific request. The request
> +		 * buffer associated with main path stream is the one that
> +		 * is required to be completed (not the internal buffer).
> +		 */
> +		for (auto it : request->buffers()) {
> +			if (it.first == &data->mainPathStream_)
> +				completeBuffer(request, it.second);
> +		}
> +
> +		tryCompleteRequest(info);
> +		return;
> +	}
> +
> +	/* Handle scaler crop control. */
> +	const auto &crop = request->controls().get(controls::ScalerCrop);
> +	if (crop) {
> +		Rectangle appliedRect = crop.value();
> +
> +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
> +						  &appliedRect);

The kernel driver doesn't handle this right :-( There's no
synchronization between setting the crop rectangle and running jobs.
You'll see glitches when zooming. That will need to be fixed in the
kernel, and the implementation in libcamera will likely need to change.
We can keep this code here for now.

> +		if (!ret && appliedRect != crop.value()) {
> +			/*
> +			 * If the rectangle is changed by setInputCrop on the
> +			 * dewarper, log a debug message and cache the actual
> +			 * applied rectangle for metadata reporting.
> +			 */
> +			LOG(RkISP1, Debug)
> +				<< "Applied rectangle " << appliedRect.toString()
> +				<< " differs from requested " << crop.value().toString();
> +		}
> +
> +		activeCrop_ = appliedRect;
> +	}
> +
> +	/*
> +	 * Queue input and output buffers to the dewarper. The output
> +	 * buffers for the dewarper are the buffers of the request, supplied
> +	 * by the application.
> +	 */
> +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
> +	if (ret < 0)
> +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
> +				   << strerror(-ret);
> +}
> +
> +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
> +{
> +	ASSERT(activeCamera_);
> +	RkISP1CameraData *data = cameraData(activeCamera_);
> +	Request *request = buffer->request();
> +
> +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
> +	if (!info)
> +		return;
> +
> +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());

You're racing with PipelineHandlerRkISP1::bufferReady(), there's no
guarantee that activeCrop_ will be the right one. In v6 you stored the
active crop in the RkISP1FrameInfo, which produced the correct
behaviour. Another option would be to set the metadata in
PipelineHandlerRkISP1::bufferReady(), which would be simpler.

> +
>  	completeBuffer(request, buffer);
>  	tryCompleteRequest(info);
>  }

On Wed, Sep 25, 2024 at 01:29:42PM +0530, Umang Jain wrote:
> On 25/09/24 1:20 pm, Stefan Klug wrote:
> > On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
> >> Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
> >> handler. If the dewarper is found, it is instantiated and buffers are
> >> exported from it, instead of RkISP1Path. Internal buffers are allocated
> >> for the RkISP1Path in case where dewarper is going to be used.
> >>
> >> The RKISP1 pipeline handler now supports scaler crop control through
> >> the converter. Register the ScalerCrop control for the cameras created
> >> in the RKISP1 pipeline handler.
> >>
> >> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> >> ---
> >>   src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
> >>   1 file changed, 176 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> >> index 651258e3..0a794d63 100644
> >> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> >> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> >> @@ -6,10 +6,12 @@
> >>    */
> >>   
> >>   #include <algorithm>
> >> +#include <map>
> >>   #include <memory>
> >>   #include <numeric>
> >>   #include <optional>
> >>   #include <queue>
> >> +#include <vector>
> >>   
> >>   #include <linux/media-bus-format.h>
> >>   #include <linux/rkisp1-config.h>
> >> @@ -32,6 +34,7 @@
> >>   
> >>   #include "libcamera/internal/camera.h"
> >>   #include "libcamera/internal/camera_sensor.h"
> >> +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
> >>   #include "libcamera/internal/delayed_controls.h"
> >>   #include "libcamera/internal/device_enumerator.h"
> >>   #include "libcamera/internal/framebuffer.h"
> >> @@ -180,6 +183,7 @@ private:
> >>   	void bufferReady(FrameBuffer *buffer);
> >>   	void paramReady(FrameBuffer *buffer);
> >>   	void statReady(FrameBuffer *buffer);
> >> +	void dewarpBufferReady(FrameBuffer *buffer);
> >>   	void frameStart(uint32_t sequence);
> >>   
> >>   	int allocateBuffers(Camera *camera);
> >> @@ -199,6 +203,15 @@ private:
> >>   	RkISP1MainPath mainPath_;
> >>   	RkISP1SelfPath selfPath_;
> >>   
> >> +	std::unique_ptr<V4L2M2MConverter> dewarper_;
> >> +	bool useDewarper_;
> >> +
> >> +	std::optional<Rectangle> activeCrop_;
> >> +
> >> +	/* Internal buffers used when dewarper is being used */
> >> +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
> >> +	std::queue<FrameBuffer *> availableMainPathBuffers_;
> >> +
> >>   	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
> >>   	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
> >>   	std::queue<FrameBuffer *> availableParamBuffers_;
> >> @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
> >>   
> >>   	FrameBuffer *paramBuffer = nullptr;
> >>   	FrameBuffer *statBuffer = nullptr;
> >> +	FrameBuffer *mainPathBuffer = nullptr;
> >> +	FrameBuffer *selfPathBuffer = nullptr;
> >>   
> >>   	if (!isRaw) {
> >>   		if (pipe_->availableParamBuffers_.empty()) {
> >> @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
> >>   
> >>   		statBuffer = pipe_->availableStatBuffers_.front();
> >>   		pipe_->availableStatBuffers_.pop();
> >> +
> >> +		if (pipe_->useDewarper_) {
> >> +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
> >> +			pipe_->availableMainPathBuffers_.pop();
> >> +		}
> >>   	}
> >>   
> >> -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> >> -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
> >> +	if (!mainPathBuffer)
> >> +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> >> +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
> >>   
> >>   	RkISP1FrameInfo *info = new RkISP1FrameInfo;
> >>   
> >> @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
> >>   
> >>   	pipe_->availableParamBuffers_.push(info->paramBuffer);
> >>   	pipe_->availableStatBuffers_.push(info->statBuffer);
> >> +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
> >>   
> >>   	frameInfo_.erase(info->frame);
> >>   
> >> @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
> >>   
> >>   		pipe_->availableParamBuffers_.push(info->paramBuffer);
> >>   		pipe_->availableStatBuffers_.push(info->statBuffer);
> >> +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
> >>   
> >>   		delete info;
> >>   	}
> >> @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
> >>    */
> >>   
> >>   PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
> >> -	: PipelineHandler(manager), hasSelfPath_(true)
> >> +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
> >>   {
> >>   }
> >>   
> >> @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
> >>   		<< " crop " << rect;
> >>   
> >>   	std::map<unsigned int, IPAStream> streamConfig;
> >> +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
> >>   
> >>   	for (const StreamConfiguration &cfg : *config) {
> >>   		if (cfg.stream() == &data->mainPathStream_) {
> >>   			ret = mainPath_.configure(cfg, format);
> >>   			streamConfig[0] = IPAStream(cfg.pixelFormat,
> >>   						    cfg.size);
> >> +			/* Configure dewarp */
> >> +			if (dewarper_ && !isRaw_) {
> >> +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
> >> +				ret = dewarper_->configure(cfg, outputCfgs);
> >> +				useDewarper_ = ret ? false : true;
> >> +			}
> >>   		} else if (hasSelfPath_) {
> >>   			ret = selfPath_.configure(cfg, format);
> >>   			streamConfig[1] = IPAStream(cfg.pixelFormat,
> >> @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
> >>   	RkISP1CameraData *data = cameraData(camera);
> >>   	unsigned int count = stream->configuration().bufferCount;
> >>   
> >> -	if (stream == &data->mainPathStream_)
> >> -		return mainPath_.exportBuffers(count, buffers);
> >> -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
> >> +	if (stream == &data->mainPathStream_) {
> >> +		/*
> >> +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
> >> +		 * It has mainpath and no self path. Hence, export buffers from
> >> +		 * dewarper just for the main path stream, for now.
> >> +		 */
> >> +		if (useDewarper_)
> >> +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
> >> +		else
> >> +			return mainPath_.exportBuffers(count, buffers);
> >> +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
> >>   		return selfPath_.exportBuffers(count, buffers);
> >> +	}
> >>   
> >>   	return -EINVAL;
> >>   }
> >> @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
> >>   		ret = stat_->allocateBuffers(maxCount, &statBuffers_);
> >
> > Is there a way for the user to prevent usage of the dewarper? It
> > increases latency and doubles the required buffers. Now that I write
> > about it. To configure actual lens dewarping I envision something like a
> > "dewarp" algorithm in the tuning file. Maybe that is the best place for
> > that decision...
> 
> I think somewhere in the previous interations, we decided that if the 
> dewarper is present, it should be discovered and used. At that point, we 
> failed to justify any use cases, where a user might have to disable the 
> dewarper 'intentionally'.
> 
> If there is use case, we can surely allow disabling the dewarper (and 
> shouldn't be a tedious patch on top, I believe). But, The justification 
> has to be there.

If the camera doesn't have a dewarping map, and if the user doesn't
request digital zoom, then I think the dewarper should be bypassed
instead of introducing delays.

I would still like to get to the bottom of using the resizer to
implement digital zoom.

> >>   		if (ret < 0)
> >>   			goto error;
> >> +
> >> +		/* If the dewarper is being used, allocate internal buffers for ISP. */
> >> +		if (useDewarper_) {
> >> +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
> >> +			if (ret < 0)
> >> +				goto error;
> >> +
> >> +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
> >> +				availableMainPathBuffers_.push(buffer.get());
> >> +		}
> >>   	}
> >>   
> >>   	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
> >> @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
> >>   error:
> >>   	paramBuffers_.clear();
> >>   	statBuffers_.clear();
> >> +	mainPathBuffers_.clear();
> >>   
> >>   	return ret;
> >>   }
> >> @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
> >>   	while (!availableParamBuffers_.empty())
> >>   		availableParamBuffers_.pop();
> >>   
> >> +	while (!availableMainPathBuffers_.empty())
> >> +		availableMainPathBuffers_.pop();
> >> +
> >>   	paramBuffers_.clear();
> >>   	statBuffers_.clear();
> >> +	mainPathBuffers_.clear();
> >>   
> >>   	std::vector<unsigned int> ids;
> >>   	for (IPABuffer &ipabuf : data->ipaBuffers_)
> >> @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
> >>   			return ret;
> >>   		}
> >>   		actions += [&]() { stat_->streamOff(); };
> >> +
> >> +		if (useDewarper_) {
> >> +			ret = dewarper_->start();
> >> +			if (ret) {
> >> +				LOG(RkISP1, Error) << "Failed to start dewarper";
> >> +				return ret;
> >> +			}
> >> +		}
> >> +		actions += [&]() { dewarper_->stop(); };
> >>   	}
> >>   
> >>   	if (data->mainPath_->isEnabled()) {
> >> @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
> >>   		if (ret)
> >>   			LOG(RkISP1, Warning)
> >>   				<< "Failed to stop parameters for " << camera->id();
> >> +
> >> +		if (useDewarper_)
> >> +			dewarper_->stop();
> >>   	}
> >>   
> >>   	ASSERT(data->queuedRequests_.empty());
> >> @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
> >>   {
> >>   	ControlInfoMap::Map controls;
> >>   
> >> +	if (dewarper_) {
> >> +		std::pair<Rectangle, Rectangle> cropLimits =
> >> +			dewarper_->inputCropBounds(&data->mainPathStream_);
> >> +
> >> +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
> >> +							      cropLimits.second,
> >> +							      cropLimits.second);
> >> +		activeCrop_ = cropLimits.second;
> >> +	}
> >> +
> >
> > I'm a bit uncertain here. The current dewarper kernel driver produces
> > quite unexpected and difficult to explain results (modified crop
> > rectangle, changed pixel aspect ratio). So to me it feels like we
> > shouldn't expose that hardware control directly to the user, but do an
> > internal implementation (based on the same libcamera control). Could we
> > split just the logic that adds the control into a separate patch?
> 
> I don't understand internal implementation based on same libcamera 
> control? How would that look like?
> 
> So, you mean to say, we don't feed any scaler crop rectangles from 
> application, but do it internally ?
>
> > Another approach would be to merge it in and improve later. But then we
> > might break the interface for users of the feature... I lean towards
> > splitting the control and merging the rest. In that case we should
> > disable the dewarper by default, as the user has no added benefit
> > without the control. Still I think all the plumbing should definitely
> > go in.
> 
> I don't foresee breaking the interface for users. But there can be 
> improvements on top of this (for e.g. mapping the V4L2 Selection flags) 
> and letting the application control that via an interface.
> 
> https://docs.kernel.org/userspace-api/media/v4l/v4l2-selection-flags.html
> 
> >>   	/* Add the IPA registered controls to list of camera controls. */
> >>   	for (const auto &ipaControl : data->ipaControls_)
> >>   		controls[ipaControl.first] = ipaControl.second;
> >> @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
> >>   	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
> >>   	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
> >>   
> >> +	/* If dewarper is present, create its instance. */
> >> +	DeviceMatch dwp("dw100");
> >> +	dwp.add("dw100-source");
> >> +	dwp.add("dw100-sink");
> >> +
> >> +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
> >> +	if (dwpMediaDevice) {
> >> +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
> >> +		if (dewarper_->isValid()) {
> >> +			dewarper_->outputBufferReady.connect(
> >> +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
> >> +
> >> +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();
> >> +		} else {
> >> +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
> >> +					     << " but invalid";
> >> +			dewarper_.reset();
> >> +		}
> >> +	}
> >> +
> >>   	/*
> >>   	 * Enumerate all sensors connected to the ISP and create one
> >>   	 * camera instance for each of them.
> >> @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
> >>   		return;
> >>   
> >>   	const FrameMetadata &metadata = buffer->metadata();
> >> -	Request *request = buffer->request();
> >> +	Request *request = info->request;
> >>   
> >>   	if (metadata.status != FrameMetadata::FrameCancelled) {
> >>   		/*
> >> @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
> >>   			info->metadataProcessed = true;
> >>   	}
> >>   
> >> +	if (!useDewarper_) {
> >> +		completeBuffer(request, buffer);
> >> +		tryCompleteRequest(info);
> >> +
> >> +		return;
> >> +	}
> >> +
> >> +	/* Do not queue cancelled frames to dewarper. */
> >> +	if (metadata.status == FrameMetadata::FrameCancelled) {
> >> +		/*
> >> +		 * i.MX8MP is the only known platform with dewarper. It has
> >> +		 * no self path. Hence, only main path buffer completion is
> >> +		 * required.
> >> +		 *
> >> +		 * Also, we cannot completeBuffer(request, buffer) as buffer
> >> +		 * here, is an internal buffer (between ISP and dewarper) and
> >> +		 * is not associated to the any specific request. The request
> >> +		 * buffer associated with main path stream is the one that
> >> +		 * is required to be completed (not the internal buffer).
> >> +		 */
> >> +		for (auto it : request->buffers()) {
> >> +			if (it.first == &data->mainPathStream_)
> >> +				completeBuffer(request, it.second);
> >> +		}
> >> +
> >> +		tryCompleteRequest(info);
> >> +		return;
> >> +	}
> >> +
> >> +	/* Handle scaler crop control. */
> >> +	const auto &crop = request->controls().get(controls::ScalerCrop);
> >> +	if (crop) {
> >> +		Rectangle appliedRect = crop.value();
> >> +
> >> +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
> >> +						  &appliedRect);
> >> +		if (!ret && appliedRect != crop.value()) {
> >> +			/*
> >> +			 * If the rectangle is changed by setInputCrop on the
> >> +			 * dewarper, log a debug message and cache the actual
> >> +			 * applied rectangle for metadata reporting.
> >> +			 */
> >> +			LOG(RkISP1, Debug)
> >> +				<< "Applied rectangle " << appliedRect.toString()
> >> +				<< " differs from requested " << crop.value().toString();
> >> +		}
> >> +
> >> +		activeCrop_ = appliedRect;
> >> +	}
> >> +
> >> +	/*
> >> +	 * Queue input and output buffers to the dewarper. The output
> >> +	 * buffers for the dewarper are the buffers of the request, supplied
> >> +	 * by the application.
> >> +	 */
> >> +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
> >> +	if (ret < 0)
> >> +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
> >> +				   << strerror(-ret);
> >> +}
> >> +
> >> +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
> >> +{
> >> +	ASSERT(activeCamera_);
> >> +	RkISP1CameraData *data = cameraData(activeCamera_);
> >> +	Request *request = buffer->request();
> >> +
> >> +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
> >> +	if (!info)
> >> +		return;
> >> +
> >> +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());
> >
> > I couldn't easily see if there are cases where more than one buffer are
> > queued to the dewarper. In that case the activeCrop_ could be the one
> > applied to the next frame. If it is ensured that that is not the case it
> > might be worth a comment.
> >
> >> +
> >>   	completeBuffer(request, buffer);
> >>   	tryCompleteRequest(info);
> >>   }

Hi Laurent,

On 26/09/24 12:12 am, Laurent Pinchart wrote:
> Hi Umang,
>
> Thank you for the patch.
>
> On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
>> Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
>> handler. If the dewarper is found, it is instantiated and buffers are
>> exported from it, instead of RkISP1Path. Internal buffers are allocated
>> for the RkISP1Path in case where dewarper is going to be used.
>>
>> The RKISP1 pipeline handler now supports scaler crop control through
>> the converter. Register the ScalerCrop control for the cameras created
>> in the RKISP1 pipeline handler.
>>
>> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
>> ---
>>   src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
>>   1 file changed, 176 insertions(+), 7 deletions(-)
>>
>> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>> index 651258e3..0a794d63 100644
>> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>> @@ -6,10 +6,12 @@
>>    */
>>   
>>   #include <algorithm>
>> +#include <map>
>>   #include <memory>
>>   #include <numeric>
>>   #include <optional>
>>   #include <queue>
>> +#include <vector>
>>   
>>   #include <linux/media-bus-format.h>
>>   #include <linux/rkisp1-config.h>
>> @@ -32,6 +34,7 @@
>>   
>>   #include "libcamera/internal/camera.h"
>>   #include "libcamera/internal/camera_sensor.h"
>> +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
>>   #include "libcamera/internal/delayed_controls.h"
>>   #include "libcamera/internal/device_enumerator.h"
>>   #include "libcamera/internal/framebuffer.h"
>> @@ -180,6 +183,7 @@ private:
>>   	void bufferReady(FrameBuffer *buffer);
>>   	void paramReady(FrameBuffer *buffer);
>>   	void statReady(FrameBuffer *buffer);
>> +	void dewarpBufferReady(FrameBuffer *buffer);
>>   	void frameStart(uint32_t sequence);
>>   
>>   	int allocateBuffers(Camera *camera);
>> @@ -199,6 +203,15 @@ private:
>>   	RkISP1MainPath mainPath_;
>>   	RkISP1SelfPath selfPath_;
>>   
>> +	std::unique_ptr<V4L2M2MConverter> dewarper_;
>> +	bool useDewarper_;
>> +
>> +	std::optional<Rectangle> activeCrop_;
>> +
>> +	/* Internal buffers used when dewarper is being used */
>> +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
>> +	std::queue<FrameBuffer *> availableMainPathBuffers_;
>> +
>>   	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
>>   	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
>>   	std::queue<FrameBuffer *> availableParamBuffers_;
>> @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>>   
>>   	FrameBuffer *paramBuffer = nullptr;
>>   	FrameBuffer *statBuffer = nullptr;
>> +	FrameBuffer *mainPathBuffer = nullptr;
>> +	FrameBuffer *selfPathBuffer = nullptr;
>>   
>>   	if (!isRaw) {
>>   		if (pipe_->availableParamBuffers_.empty()) {
>> @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>>   
>>   		statBuffer = pipe_->availableStatBuffers_.front();
>>   		pipe_->availableStatBuffers_.pop();
>> +
>> +		if (pipe_->useDewarper_) {
>> +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
>> +			pipe_->availableMainPathBuffers_.pop();
>> +		}
>>   	}
>>   
>> -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
>> -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>> +	if (!mainPathBuffer)
>> +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
>> +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>>   
>>   	RkISP1FrameInfo *info = new RkISP1FrameInfo;
>>   
>> @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
>>   
>>   	pipe_->availableParamBuffers_.push(info->paramBuffer);
>>   	pipe_->availableStatBuffers_.push(info->statBuffer);
>> +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>>   
>>   	frameInfo_.erase(info->frame);
>>   
>> @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
>>   
>>   		pipe_->availableParamBuffers_.push(info->paramBuffer);
>>   		pipe_->availableStatBuffers_.push(info->statBuffer);
>> +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>>   
>>   		delete info;
>>   	}
>> @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
>>    */
>>   
>>   PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
>> -	: PipelineHandler(manager), hasSelfPath_(true)
>> +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
>>   {
>>   }
>>   
>> @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
>>   		<< " crop " << rect;
>>   
>>   	std::map<unsigned int, IPAStream> streamConfig;
>> +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
>>   
>>   	for (const StreamConfiguration &cfg : *config) {
>>   		if (cfg.stream() == &data->mainPathStream_) {
>>   			ret = mainPath_.configure(cfg, format);
>>   			streamConfig[0] = IPAStream(cfg.pixelFormat,
>>   						    cfg.size);
>> +			/* Configure dewarp */
>> +			if (dewarper_ && !isRaw_) {
>> +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
>> +				ret = dewarper_->configure(cfg, outputCfgs);
>> +				useDewarper_ = ret ? false : true;
>> +			}
>>   		} else if (hasSelfPath_) {
>>   			ret = selfPath_.configure(cfg, format);
>>   			streamConfig[1] = IPAStream(cfg.pixelFormat,
>> @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
>>   	RkISP1CameraData *data = cameraData(camera);
>>   	unsigned int count = stream->configuration().bufferCount;
>>   
>> -	if (stream == &data->mainPathStream_)
>> -		return mainPath_.exportBuffers(count, buffers);
>> -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
>> +	if (stream == &data->mainPathStream_) {
>> +		/*
>> +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
>> +		 * It has mainpath and no self path. Hence, export buffers from
>> +		 * dewarper just for the main path stream, for now.
>> +		 */
>> +		if (useDewarper_)
>> +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
>> +		else
>> +			return mainPath_.exportBuffers(count, buffers);
>> +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
>>   		return selfPath_.exportBuffers(count, buffers);
>> +	}
>>   
>>   	return -EINVAL;
>>   }
>> @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>>   		ret = stat_->allocateBuffers(maxCount, &statBuffers_);
>>   		if (ret < 0)
>>   			goto error;
>> +
>> +		/* If the dewarper is being used, allocate internal buffers for ISP. */
>> +		if (useDewarper_) {
>> +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
>> +			if (ret < 0)
>> +				goto error;
>> +
>> +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
>> +				availableMainPathBuffers_.push(buffer.get());
>> +		}
>>   	}
>>   
>>   	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
>> @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>>   error:
>>   	paramBuffers_.clear();
>>   	statBuffers_.clear();
>> +	mainPathBuffers_.clear();
>>   
>>   	return ret;
>>   }
>> @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>>   	while (!availableParamBuffers_.empty())
>>   		availableParamBuffers_.pop();
>>   
>> +	while (!availableMainPathBuffers_.empty())
>> +		availableMainPathBuffers_.pop();
>> +
>>   	paramBuffers_.clear();
>>   	statBuffers_.clear();
>> +	mainPathBuffers_.clear();
>>   
>>   	std::vector<unsigned int> ids;
>>   	for (IPABuffer &ipabuf : data->ipaBuffers_)
>> @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
>>   			return ret;
>>   		}
>>   		actions += [&]() { stat_->streamOff(); };
>> +
>> +		if (useDewarper_) {
>> +			ret = dewarper_->start();
>> +			if (ret) {
>> +				LOG(RkISP1, Error) << "Failed to start dewarper";
>> +				return ret;
>> +			}
>> +		}
>> +		actions += [&]() { dewarper_->stop(); };
>>   	}
>>   
>>   	if (data->mainPath_->isEnabled()) {
>> @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
>>   		if (ret)
>>   			LOG(RkISP1, Warning)
>>   				<< "Failed to stop parameters for " << camera->id();
>> +
>> +		if (useDewarper_)
>> +			dewarper_->stop();
>>   	}
>>   
>>   	ASSERT(data->queuedRequests_.empty());
>> @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
>>   {
>>   	ControlInfoMap::Map controls;
>>   
>> +	if (dewarper_) {
>> +		std::pair<Rectangle, Rectangle> cropLimits =
>> +			dewarper_->inputCropBounds(&data->mainPathStream_);
>> +
>> +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
>> +							      cropLimits.second,
>> +							      cropLimits.second);
>> +		activeCrop_ = cropLimits.second;
>> +	}
>> +
>>   	/* Add the IPA registered controls to list of camera controls. */
>>   	for (const auto &ipaControl : data->ipaControls_)
>>   		controls[ipaControl.first] = ipaControl.second;
>> @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
>>   	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
>>   	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
>>   
>> +	/* If dewarper is present, create its instance. */
>> +	DeviceMatch dwp("dw100");
>> +	dwp.add("dw100-source");
>> +	dwp.add("dw100-sink");
>> +
>> +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
>> +	if (dwpMediaDevice) {
>> +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
>> +		if (dewarper_->isValid()) {
>> +			dewarper_->outputBufferReady.connect(
>> +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
>> +
>> +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();
> 			LOG(RkISP1, Info)
> 				<< "Using DW100 dewarper " << dewarper_->deviceNode();
> 			
>> +		} else {
>> +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
>> +					     << " but invalid";
> 			LOG(RkISP1, Warning)
> 				<< "Found DW100 dewarper " << dewarper_->deviceNode()
> 				<< " but invalid";
>
>> +			dewarper_.reset();
>> +		}
>> +	}
>> +
>>   	/*
>>   	 * Enumerate all sensors connected to the ISP and create one
>>   	 * camera instance for each of them.
>> @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>>   		return;
>>   
>>   	const FrameMetadata &metadata = buffer->metadata();
>> -	Request *request = buffer->request();
>> +	Request *request = info->request;
>>   
>>   	if (metadata.status != FrameMetadata::FrameCancelled) {
>>   		/*
>> @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>>   			info->metadataProcessed = true;
>>   	}
>>   
>> +	if (!useDewarper_) {
>> +		completeBuffer(request, buffer);
>> +		tryCompleteRequest(info);
>> +
>> +		return;
>> +	}
>> +
>> +	/* Do not queue cancelled frames to dewarper. */
>> +	if (metadata.status == FrameMetadata::FrameCancelled) {
>> +		/*
>> +		 * i.MX8MP is the only known platform with dewarper. It has
>> +		 * no self path. Hence, only main path buffer completion is
>> +		 * required.
>> +		 *
>> +		 * Also, we cannot completeBuffer(request, buffer) as buffer
>> +		 * here, is an internal buffer (between ISP and dewarper) and
>> +		 * is not associated to the any specific request. The request
>> +		 * buffer associated with main path stream is the one that
>> +		 * is required to be completed (not the internal buffer).
>> +		 */
>> +		for (auto it : request->buffers()) {
>> +			if (it.first == &data->mainPathStream_)
>> +				completeBuffer(request, it.second);
>> +		}
>> +
>> +		tryCompleteRequest(info);
>> +		return;
>> +	}
>> +
>> +	/* Handle scaler crop control. */
>> +	const auto &crop = request->controls().get(controls::ScalerCrop);
>> +	if (crop) {
>> +		Rectangle appliedRect = crop.value();
>> +
>> +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
>> +						  &appliedRect);
> The kernel driver doesn't handle this right :-( There's no
> synchronization between setting the crop rectangle and running jobs.
> You'll see glitches when zooming. That will need to be fixed in the
> kernel, and the implementation in libcamera will likely need to change.
> We can keep this code here for now.
>
>> +		if (!ret && appliedRect != crop.value()) {
>> +			/*
>> +			 * If the rectangle is changed by setInputCrop on the
>> +			 * dewarper, log a debug message and cache the actual
>> +			 * applied rectangle for metadata reporting.
>> +			 */
>> +			LOG(RkISP1, Debug)
>> +				<< "Applied rectangle " << appliedRect.toString()
>> +				<< " differs from requested " << crop.value().toString();
>> +		}
>> +
>> +		activeCrop_ = appliedRect;
>> +	}
>> +
>> +	/*
>> +	 * Queue input and output buffers to the dewarper. The output
>> +	 * buffers for the dewarper are the buffers of the request, supplied
>> +	 * by the application.
>> +	 */
>> +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
>> +	if (ret < 0)
>> +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
>> +				   << strerror(-ret);
>> +}
>> +
>> +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
>> +{
>> +	ASSERT(activeCamera_);
>> +	RkISP1CameraData *data = cameraData(activeCamera_);
>> +	Request *request = buffer->request();
>> +
>> +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
>> +	if (!info)
>> +		return;
>> +
>> +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());
> You're racing with PipelineHandlerRkISP1::bufferReady(), there's no
> guarantee that activeCrop_ will be the right one. In v6 you stored the
> active crop in the RkISP1FrameInfo, which produced the correct
> behaviour. Another option would be to set the metadata in
> PipelineHandlerRkISP1::bufferReady(), which would be simpler.

Ah yes, this get's racy.

I've opted for for the latter, i.e. setting the metadata in bufferReady()
>
>> +
>>   	completeBuffer(request, buffer);
>>   	tryCompleteRequest(info);
>>   }

Hi Laurent,

On 26/09/24 12:16 am, Laurent Pinchart wrote:
> On Wed, Sep 25, 2024 at 01:29:42PM +0530, Umang Jain wrote:
>> On 25/09/24 1:20 pm, Stefan Klug wrote:
>>> On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
>>>> Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
>>>> handler. If the dewarper is found, it is instantiated and buffers are
>>>> exported from it, instead of RkISP1Path. Internal buffers are allocated
>>>> for the RkISP1Path in case where dewarper is going to be used.
>>>>
>>>> The RKISP1 pipeline handler now supports scaler crop control through
>>>> the converter. Register the ScalerCrop control for the cameras created
>>>> in the RKISP1 pipeline handler.
>>>>
>>>> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
>>>> ---
>>>>    src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
>>>>    1 file changed, 176 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>>>> index 651258e3..0a794d63 100644
>>>> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>>>> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
>>>> @@ -6,10 +6,12 @@
>>>>     */
>>>>    
>>>>    #include <algorithm>
>>>> +#include <map>
>>>>    #include <memory>
>>>>    #include <numeric>
>>>>    #include <optional>
>>>>    #include <queue>
>>>> +#include <vector>
>>>>    
>>>>    #include <linux/media-bus-format.h>
>>>>    #include <linux/rkisp1-config.h>
>>>> @@ -32,6 +34,7 @@
>>>>    
>>>>    #include "libcamera/internal/camera.h"
>>>>    #include "libcamera/internal/camera_sensor.h"
>>>> +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
>>>>    #include "libcamera/internal/delayed_controls.h"
>>>>    #include "libcamera/internal/device_enumerator.h"
>>>>    #include "libcamera/internal/framebuffer.h"
>>>> @@ -180,6 +183,7 @@ private:
>>>>    	void bufferReady(FrameBuffer *buffer);
>>>>    	void paramReady(FrameBuffer *buffer);
>>>>    	void statReady(FrameBuffer *buffer);
>>>> +	void dewarpBufferReady(FrameBuffer *buffer);
>>>>    	void frameStart(uint32_t sequence);
>>>>    
>>>>    	int allocateBuffers(Camera *camera);
>>>> @@ -199,6 +203,15 @@ private:
>>>>    	RkISP1MainPath mainPath_;
>>>>    	RkISP1SelfPath selfPath_;
>>>>    
>>>> +	std::unique_ptr<V4L2M2MConverter> dewarper_;
>>>> +	bool useDewarper_;
>>>> +
>>>> +	std::optional<Rectangle> activeCrop_;
>>>> +
>>>> +	/* Internal buffers used when dewarper is being used */
>>>> +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
>>>> +	std::queue<FrameBuffer *> availableMainPathBuffers_;
>>>> +
>>>>    	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
>>>>    	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
>>>>    	std::queue<FrameBuffer *> availableParamBuffers_;
>>>> @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>>>>    
>>>>    	FrameBuffer *paramBuffer = nullptr;
>>>>    	FrameBuffer *statBuffer = nullptr;
>>>> +	FrameBuffer *mainPathBuffer = nullptr;
>>>> +	FrameBuffer *selfPathBuffer = nullptr;
>>>>    
>>>>    	if (!isRaw) {
>>>>    		if (pipe_->availableParamBuffers_.empty()) {
>>>> @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
>>>>    
>>>>    		statBuffer = pipe_->availableStatBuffers_.front();
>>>>    		pipe_->availableStatBuffers_.pop();
>>>> +
>>>> +		if (pipe_->useDewarper_) {
>>>> +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
>>>> +			pipe_->availableMainPathBuffers_.pop();
>>>> +		}
>>>>    	}
>>>>    
>>>> -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
>>>> -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>>>> +	if (!mainPathBuffer)
>>>> +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
>>>> +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
>>>>    
>>>>    	RkISP1FrameInfo *info = new RkISP1FrameInfo;
>>>>    
>>>> @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
>>>>    
>>>>    	pipe_->availableParamBuffers_.push(info->paramBuffer);
>>>>    	pipe_->availableStatBuffers_.push(info->statBuffer);
>>>> +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>>>>    
>>>>    	frameInfo_.erase(info->frame);
>>>>    
>>>> @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
>>>>    
>>>>    		pipe_->availableParamBuffers_.push(info->paramBuffer);
>>>>    		pipe_->availableStatBuffers_.push(info->statBuffer);
>>>> +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
>>>>    
>>>>    		delete info;
>>>>    	}
>>>> @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
>>>>     */
>>>>    
>>>>    PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
>>>> -	: PipelineHandler(manager), hasSelfPath_(true)
>>>> +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
>>>>    {
>>>>    }
>>>>    
>>>> @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
>>>>    		<< " crop " << rect;
>>>>    
>>>>    	std::map<unsigned int, IPAStream> streamConfig;
>>>> +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
>>>>    
>>>>    	for (const StreamConfiguration &cfg : *config) {
>>>>    		if (cfg.stream() == &data->mainPathStream_) {
>>>>    			ret = mainPath_.configure(cfg, format);
>>>>    			streamConfig[0] = IPAStream(cfg.pixelFormat,
>>>>    						    cfg.size);
>>>> +			/* Configure dewarp */
>>>> +			if (dewarper_ && !isRaw_) {
>>>> +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
>>>> +				ret = dewarper_->configure(cfg, outputCfgs);
>>>> +				useDewarper_ = ret ? false : true;
>>>> +			}
>>>>    		} else if (hasSelfPath_) {
>>>>    			ret = selfPath_.configure(cfg, format);
>>>>    			streamConfig[1] = IPAStream(cfg.pixelFormat,
>>>> @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
>>>>    	RkISP1CameraData *data = cameraData(camera);
>>>>    	unsigned int count = stream->configuration().bufferCount;
>>>>    
>>>> -	if (stream == &data->mainPathStream_)
>>>> -		return mainPath_.exportBuffers(count, buffers);
>>>> -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
>>>> +	if (stream == &data->mainPathStream_) {
>>>> +		/*
>>>> +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
>>>> +		 * It has mainpath and no self path. Hence, export buffers from
>>>> +		 * dewarper just for the main path stream, for now.
>>>> +		 */
>>>> +		if (useDewarper_)
>>>> +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
>>>> +		else
>>>> +			return mainPath_.exportBuffers(count, buffers);
>>>> +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
>>>>    		return selfPath_.exportBuffers(count, buffers);
>>>> +	}
>>>>    
>>>>    	return -EINVAL;
>>>>    }
>>>> @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>>>>    		ret = stat_->allocateBuffers(maxCount, &statBuffers_);
>>> Is there a way for the user to prevent usage of the dewarper? It
>>> increases latency and doubles the required buffers. Now that I write
>>> about it. To configure actual lens dewarping I envision something like a
>>> "dewarp" algorithm in the tuning file. Maybe that is the best place for
>>> that decision...
>> I think somewhere in the previous interations, we decided that if the
>> dewarper is present, it should be discovered and used. At that point, we
>> failed to justify any use cases, where a user might have to disable the
>> dewarper 'intentionally'.
>>
>> If there is use case, we can surely allow disabling the dewarper (and
>> shouldn't be a tedious patch on top, I believe). But, The justification
>> has to be there.
> If the camera doesn't have a dewarping map, and if the user doesn't
> request digital zoom, then I think the dewarper should be bypassed
> instead of introducing delays.

Behavior seems okay to me. Bypassing the dewarper should be handled when 
plumbing the vertex map, I think ? Stefan, what do you think?


>
> I would still like to get to the bottom of using the resizer to
> implement digital zoom.

Any specific reasons?  Dewarper gives us better digital zoom 
capabilities limits, last I checked.

>
>>>>    		if (ret < 0)
>>>>    			goto error;
>>>> +
>>>> +		/* If the dewarper is being used, allocate internal buffers for ISP. */
>>>> +		if (useDewarper_) {
>>>> +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
>>>> +			if (ret < 0)
>>>> +				goto error;
>>>> +
>>>> +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
>>>> +				availableMainPathBuffers_.push(buffer.get());
>>>> +		}
>>>>    	}
>>>>    
>>>>    	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
>>>> @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
>>>>    error:
>>>>    	paramBuffers_.clear();
>>>>    	statBuffers_.clear();
>>>> +	mainPathBuffers_.clear();
>>>>    
>>>>    	return ret;
>>>>    }
>>>> @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>>>>    	while (!availableParamBuffers_.empty())
>>>>    		availableParamBuffers_.pop();
>>>>    
>>>> +	while (!availableMainPathBuffers_.empty())
>>>> +		availableMainPathBuffers_.pop();
>>>> +
>>>>    	paramBuffers_.clear();
>>>>    	statBuffers_.clear();
>>>> +	mainPathBuffers_.clear();
>>>>    
>>>>    	std::vector<unsigned int> ids;
>>>>    	for (IPABuffer &ipabuf : data->ipaBuffers_)
>>>> @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
>>>>    			return ret;
>>>>    		}
>>>>    		actions += [&]() { stat_->streamOff(); };
>>>> +
>>>> +		if (useDewarper_) {
>>>> +			ret = dewarper_->start();
>>>> +			if (ret) {
>>>> +				LOG(RkISP1, Error) << "Failed to start dewarper";
>>>> +				return ret;
>>>> +			}
>>>> +		}
>>>> +		actions += [&]() { dewarper_->stop(); };
>>>>    	}
>>>>    
>>>>    	if (data->mainPath_->isEnabled()) {
>>>> @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
>>>>    		if (ret)
>>>>    			LOG(RkISP1, Warning)
>>>>    				<< "Failed to stop parameters for " << camera->id();
>>>> +
>>>> +		if (useDewarper_)
>>>> +			dewarper_->stop();
>>>>    	}
>>>>    
>>>>    	ASSERT(data->queuedRequests_.empty());
>>>> @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
>>>>    {
>>>>    	ControlInfoMap::Map controls;
>>>>    
>>>> +	if (dewarper_) {
>>>> +		std::pair<Rectangle, Rectangle> cropLimits =
>>>> +			dewarper_->inputCropBounds(&data->mainPathStream_);
>>>> +
>>>> +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
>>>> +							      cropLimits.second,
>>>> +							      cropLimits.second);
>>>> +		activeCrop_ = cropLimits.second;
>>>> +	}
>>>> +
>>> I'm a bit uncertain here. The current dewarper kernel driver produces
>>> quite unexpected and difficult to explain results (modified crop
>>> rectangle, changed pixel aspect ratio). So to me it feels like we
>>> shouldn't expose that hardware control directly to the user, but do an
>>> internal implementation (based on the same libcamera control). Could we
>>> split just the logic that adds the control into a separate patch?
>> I don't understand internal implementation based on same libcamera
>> control? How would that look like?
>>
>> So, you mean to say, we don't feed any scaler crop rectangles from
>> application, but do it internally ?
>>
>>> Another approach would be to merge it in and improve later. But then we
>>> might break the interface for users of the feature... I lean towards
>>> splitting the control and merging the rest. In that case we should
>>> disable the dewarper by default, as the user has no added benefit
>>> without the control. Still I think all the plumbing should definitely
>>> go in.
>> I don't foresee breaking the interface for users. But there can be
>> improvements on top of this (for e.g. mapping the V4L2 Selection flags)
>> and letting the application control that via an interface.
>>
>> https://docs.kernel.org/userspace-api/media/v4l/v4l2-selection-flags.html
>>
>>>>    	/* Add the IPA registered controls to list of camera controls. */
>>>>    	for (const auto &ipaControl : data->ipaControls_)
>>>>    		controls[ipaControl.first] = ipaControl.second;
>>>> @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
>>>>    	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
>>>>    	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
>>>>    
>>>> +	/* If dewarper is present, create its instance. */
>>>> +	DeviceMatch dwp("dw100");
>>>> +	dwp.add("dw100-source");
>>>> +	dwp.add("dw100-sink");
>>>> +
>>>> +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
>>>> +	if (dwpMediaDevice) {
>>>> +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
>>>> +		if (dewarper_->isValid()) {
>>>> +			dewarper_->outputBufferReady.connect(
>>>> +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
>>>> +
>>>> +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();
>>>> +		} else {
>>>> +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
>>>> +					     << " but invalid";
>>>> +			dewarper_.reset();
>>>> +		}
>>>> +	}
>>>> +
>>>>    	/*
>>>>    	 * Enumerate all sensors connected to the ISP and create one
>>>>    	 * camera instance for each of them.
>>>> @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>>>>    		return;
>>>>    
>>>>    	const FrameMetadata &metadata = buffer->metadata();
>>>> -	Request *request = buffer->request();
>>>> +	Request *request = info->request;
>>>>    
>>>>    	if (metadata.status != FrameMetadata::FrameCancelled) {
>>>>    		/*
>>>> @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
>>>>    			info->metadataProcessed = true;
>>>>    	}
>>>>    
>>>> +	if (!useDewarper_) {
>>>> +		completeBuffer(request, buffer);
>>>> +		tryCompleteRequest(info);
>>>> +
>>>> +		return;
>>>> +	}
>>>> +
>>>> +	/* Do not queue cancelled frames to dewarper. */
>>>> +	if (metadata.status == FrameMetadata::FrameCancelled) {
>>>> +		/*
>>>> +		 * i.MX8MP is the only known platform with dewarper. It has
>>>> +		 * no self path. Hence, only main path buffer completion is
>>>> +		 * required.
>>>> +		 *
>>>> +		 * Also, we cannot completeBuffer(request, buffer) as buffer
>>>> +		 * here, is an internal buffer (between ISP and dewarper) and
>>>> +		 * is not associated to the any specific request. The request
>>>> +		 * buffer associated with main path stream is the one that
>>>> +		 * is required to be completed (not the internal buffer).
>>>> +		 */
>>>> +		for (auto it : request->buffers()) {
>>>> +			if (it.first == &data->mainPathStream_)
>>>> +				completeBuffer(request, it.second);
>>>> +		}
>>>> +
>>>> +		tryCompleteRequest(info);
>>>> +		return;
>>>> +	}
>>>> +
>>>> +	/* Handle scaler crop control. */
>>>> +	const auto &crop = request->controls().get(controls::ScalerCrop);
>>>> +	if (crop) {
>>>> +		Rectangle appliedRect = crop.value();
>>>> +
>>>> +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
>>>> +						  &appliedRect);
>>>> +		if (!ret && appliedRect != crop.value()) {
>>>> +			/*
>>>> +			 * If the rectangle is changed by setInputCrop on the
>>>> +			 * dewarper, log a debug message and cache the actual
>>>> +			 * applied rectangle for metadata reporting.
>>>> +			 */
>>>> +			LOG(RkISP1, Debug)
>>>> +				<< "Applied rectangle " << appliedRect.toString()
>>>> +				<< " differs from requested " << crop.value().toString();
>>>> +		}
>>>> +
>>>> +		activeCrop_ = appliedRect;
>>>> +	}
>>>> +
>>>> +	/*
>>>> +	 * Queue input and output buffers to the dewarper. The output
>>>> +	 * buffers for the dewarper are the buffers of the request, supplied
>>>> +	 * by the application.
>>>> +	 */
>>>> +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
>>>> +	if (ret < 0)
>>>> +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
>>>> +				   << strerror(-ret);
>>>> +}
>>>> +
>>>> +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
>>>> +{
>>>> +	ASSERT(activeCamera_);
>>>> +	RkISP1CameraData *data = cameraData(activeCamera_);
>>>> +	Request *request = buffer->request();
>>>> +
>>>> +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
>>>> +	if (!info)
>>>> +		return;
>>>> +
>>>> +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());
>>> I couldn't easily see if there are cases where more than one buffer are
>>> queued to the dewarper. In that case the activeCrop_ could be the one
>>> applied to the next frame. If it is ensured that that is not the case it
>>> might be worth a comment.
>>>
>>>> +
>>>>    	completeBuffer(request, buffer);
>>>>    	tryCompleteRequest(info);
>>>>    }

Hi Umang,

On Thu, Sep 26, 2024 at 01:13:24PM +0530, Umang Jain wrote:
> Hi Laurent,
> 
> On 26/09/24 12:16 am, Laurent Pinchart wrote:
> > On Wed, Sep 25, 2024 at 01:29:42PM +0530, Umang Jain wrote:
> > > On 25/09/24 1:20 pm, Stefan Klug wrote:
> > > > On Fri, Sep 06, 2024 at 12:04:44PM +0530, Umang Jain wrote:
> > > > > Plumb the dw100 dewarper as a V4L2M2M converter in the rkisp1 pipeline
> > > > > handler. If the dewarper is found, it is instantiated and buffers are
> > > > > exported from it, instead of RkISP1Path. Internal buffers are allocated
> > > > > for the RkISP1Path in case where dewarper is going to be used.
> > > > > 
> > > > > The RKISP1 pipeline handler now supports scaler crop control through
> > > > > the converter. Register the ScalerCrop control for the cameras created
> > > > > in the RKISP1 pipeline handler.
> > > > > 
> > > > > Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> > > > > ---
> > > > >    src/libcamera/pipeline/rkisp1/rkisp1.cpp | 183 ++++++++++++++++++++++-
> > > > >    1 file changed, 176 insertions(+), 7 deletions(-)
> > > > > 
> > > > > diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> > > > > index 651258e3..0a794d63 100644
> > > > > --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> > > > > +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> > > > > @@ -6,10 +6,12 @@
> > > > >     */
> > > > >    #include <algorithm>
> > > > > +#include <map>
> > > > >    #include <memory>
> > > > >    #include <numeric>
> > > > >    #include <optional>
> > > > >    #include <queue>
> > > > > +#include <vector>
> > > > >    #include <linux/media-bus-format.h>
> > > > >    #include <linux/rkisp1-config.h>
> > > > > @@ -32,6 +34,7 @@
> > > > >    #include "libcamera/internal/camera.h"
> > > > >    #include "libcamera/internal/camera_sensor.h"
> > > > > +#include "libcamera/internal/converter/converter_v4l2_m2m.h"
> > > > >    #include "libcamera/internal/delayed_controls.h"
> > > > >    #include "libcamera/internal/device_enumerator.h"
> > > > >    #include "libcamera/internal/framebuffer.h"
> > > > > @@ -180,6 +183,7 @@ private:
> > > > >    	void bufferReady(FrameBuffer *buffer);
> > > > >    	void paramReady(FrameBuffer *buffer);
> > > > >    	void statReady(FrameBuffer *buffer);
> > > > > +	void dewarpBufferReady(FrameBuffer *buffer);
> > > > >    	void frameStart(uint32_t sequence);
> > > > >    	int allocateBuffers(Camera *camera);
> > > > > @@ -199,6 +203,15 @@ private:
> > > > >    	RkISP1MainPath mainPath_;
> > > > >    	RkISP1SelfPath selfPath_;
> > > > > +	std::unique_ptr<V4L2M2MConverter> dewarper_;
> > > > > +	bool useDewarper_;
> > > > > +
> > > > > +	std::optional<Rectangle> activeCrop_;
> > > > > +
> > > > > +	/* Internal buffers used when dewarper is being used */
> > > > > +	std::vector<std::unique_ptr<FrameBuffer>> mainPathBuffers_;
> > > > > +	std::queue<FrameBuffer *> availableMainPathBuffers_;
> > > > > +
> > > > >    	std::vector<std::unique_ptr<FrameBuffer>> paramBuffers_;
> > > > >    	std::vector<std::unique_ptr<FrameBuffer>> statBuffers_;
> > > > >    	std::queue<FrameBuffer *> availableParamBuffers_;
> > > > > @@ -221,6 +234,8 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
> > > > >    	FrameBuffer *paramBuffer = nullptr;
> > > > >    	FrameBuffer *statBuffer = nullptr;
> > > > > +	FrameBuffer *mainPathBuffer = nullptr;
> > > > > +	FrameBuffer *selfPathBuffer = nullptr;
> > > > >    	if (!isRaw) {
> > > > >    		if (pipe_->availableParamBuffers_.empty()) {
> > > > > @@ -238,10 +253,16 @@ RkISP1FrameInfo *RkISP1Frames::create(const RkISP1CameraData *data, Request *req
> > > > >    		statBuffer = pipe_->availableStatBuffers_.front();
> > > > >    		pipe_->availableStatBuffers_.pop();
> > > > > +
> > > > > +		if (pipe_->useDewarper_) {
> > > > > +			mainPathBuffer = pipe_->availableMainPathBuffers_.front();
> > > > > +			pipe_->availableMainPathBuffers_.pop();
> > > > > +		}
> > > > >    	}
> > > > > -	FrameBuffer *mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> > > > > -	FrameBuffer *selfPathBuffer = request->findBuffer(&data->selfPathStream_);
> > > > > +	if (!mainPathBuffer)
> > > > > +		mainPathBuffer = request->findBuffer(&data->mainPathStream_);
> > > > > +	selfPathBuffer = request->findBuffer(&data->selfPathStream_);
> > > > >    	RkISP1FrameInfo *info = new RkISP1FrameInfo;
> > > > > @@ -267,6 +288,7 @@ int RkISP1Frames::destroy(unsigned int frame)
> > > > >    	pipe_->availableParamBuffers_.push(info->paramBuffer);
> > > > >    	pipe_->availableStatBuffers_.push(info->statBuffer);
> > > > > +	pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
> > > > >    	frameInfo_.erase(info->frame);
> > > > > @@ -282,6 +304,7 @@ void RkISP1Frames::clear()
> > > > >    		pipe_->availableParamBuffers_.push(info->paramBuffer);
> > > > >    		pipe_->availableStatBuffers_.push(info->statBuffer);
> > > > > +		pipe_->availableMainPathBuffers_.push(info->mainPathBuffer);
> > > > >    		delete info;
> > > > >    	}
> > > > > @@ -600,7 +623,7 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
> > > > >     */
> > > > >    PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
> > > > > -	: PipelineHandler(manager), hasSelfPath_(true)
> > > > > +	: PipelineHandler(manager), hasSelfPath_(true), useDewarper_(false)
> > > > >    {
> > > > >    }
> > > > > @@ -778,12 +801,19 @@ int PipelineHandlerRkISP1::configure(Camera *camera, CameraConfiguration *c)
> > > > >    		<< " crop " << rect;
> > > > >    	std::map<unsigned int, IPAStream> streamConfig;
> > > > > +	std::vector<std::reference_wrapper<StreamConfiguration>> outputCfgs;
> > > > >    	for (const StreamConfiguration &cfg : *config) {
> > > > >    		if (cfg.stream() == &data->mainPathStream_) {
> > > > >    			ret = mainPath_.configure(cfg, format);
> > > > >    			streamConfig[0] = IPAStream(cfg.pixelFormat,
> > > > >    						    cfg.size);
> > > > > +			/* Configure dewarp */
> > > > > +			if (dewarper_ && !isRaw_) {
> > > > > +				outputCfgs.push_back(const_cast<StreamConfiguration &>(cfg));
> > > > > +				ret = dewarper_->configure(cfg, outputCfgs);
> > > > > +				useDewarper_ = ret ? false : true;
> > > > > +			}
> > > > >    		} else if (hasSelfPath_) {
> > > > >    			ret = selfPath_.configure(cfg, format);
> > > > >    			streamConfig[1] = IPAStream(cfg.pixelFormat,
> > > > > @@ -833,10 +863,19 @@ int PipelineHandlerRkISP1::exportFrameBuffers([[maybe_unused]] Camera *camera, S
> > > > >    	RkISP1CameraData *data = cameraData(camera);
> > > > >    	unsigned int count = stream->configuration().bufferCount;
> > > > > -	if (stream == &data->mainPathStream_)
> > > > > -		return mainPath_.exportBuffers(count, buffers);
> > > > > -	else if (hasSelfPath_ && stream == &data->selfPathStream_)
> > > > > +	if (stream == &data->mainPathStream_) {
> > > > > +		/*
> > > > > +		 * Currently, i.MX8MP is the only platform with DW100 dewarper.
> > > > > +		 * It has mainpath and no self path. Hence, export buffers from
> > > > > +		 * dewarper just for the main path stream, for now.
> > > > > +		 */
> > > > > +		if (useDewarper_)
> > > > > +			return dewarper_->exportBuffers(&data->mainPathStream_, count, buffers);
> > > > > +		else
> > > > > +			return mainPath_.exportBuffers(count, buffers);
> > > > > +	} else if (hasSelfPath_ && stream == &data->selfPathStream_) {
> > > > >    		return selfPath_.exportBuffers(count, buffers);
> > > > > +	}
> > > > >    	return -EINVAL;
> > > > >    }
> > > > > @@ -860,6 +899,16 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
> > > > >    		ret = stat_->allocateBuffers(maxCount, &statBuffers_);
> > > > Is there a way for the user to prevent usage of the dewarper? It
> > > > increases latency and doubles the required buffers. Now that I write
> > > > about it. To configure actual lens dewarping I envision something like a
> > > > "dewarp" algorithm in the tuning file. Maybe that is the best place for
> > > > that decision...
> > > I think somewhere in the previous interations, we decided that if the
> > > dewarper is present, it should be discovered and used. At that point, we
> > > failed to justify any use cases, where a user might have to disable the
> > > dewarper 'intentionally'.
> > > 
> > > If there is use case, we can surely allow disabling the dewarper (and
> > > shouldn't be a tedious patch on top, I believe). But, The justification
> > > has to be there.
> > If the camera doesn't have a dewarping map, and if the user doesn't
> > request digital zoom, then I think the dewarper should be bypassed
> > instead of introducing delays.
> 
> Behavior seems okay to me. Bypassing the dewarper should be handled when
> plumbing the vertex map, I think ? Stefan, what do you think?

I'm fine with either way. It is most likely easier to merge it in as it
is now.  The chances are pretty good, that we can get the vertex map
support in before the next release.

Regards,
Stefan

> 
> 
> > 
> > I would still like to get to the bottom of using the resizer to
> > implement digital zoom.
> 
> Any specific reasons?  Dewarper gives us better digital zoom capabilities
> limits, last I checked.
> 
> > 
> > > > >    		if (ret < 0)
> > > > >    			goto error;
> > > > > +
> > > > > +		/* If the dewarper is being used, allocate internal buffers for ISP. */
> > > > > +		if (useDewarper_) {
> > > > > +			ret = mainPath_.exportBuffers(maxCount, &mainPathBuffers_);
> > > > > +			if (ret < 0)
> > > > > +				goto error;
> > > > > +
> > > > > +			for (std::unique_ptr<FrameBuffer> &buffer : mainPathBuffers_)
> > > > > +				availableMainPathBuffers_.push(buffer.get());
> > > > > +		}
> > > > >    	}
> > > > >    	for (std::unique_ptr<FrameBuffer> &buffer : paramBuffers_) {
> > > > > @@ -883,6 +932,7 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
> > > > >    error:
> > > > >    	paramBuffers_.clear();
> > > > >    	statBuffers_.clear();
> > > > > +	mainPathBuffers_.clear();
> > > > >    	return ret;
> > > > >    }
> > > > > @@ -897,8 +947,12 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
> > > > >    	while (!availableParamBuffers_.empty())
> > > > >    		availableParamBuffers_.pop();
> > > > > +	while (!availableMainPathBuffers_.empty())
> > > > > +		availableMainPathBuffers_.pop();
> > > > > +
> > > > >    	paramBuffers_.clear();
> > > > >    	statBuffers_.clear();
> > > > > +	mainPathBuffers_.clear();
> > > > >    	std::vector<unsigned int> ids;
> > > > >    	for (IPABuffer &ipabuf : data->ipaBuffers_)
> > > > > @@ -954,6 +1008,15 @@ int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlL
> > > > >    			return ret;
> > > > >    		}
> > > > >    		actions += [&]() { stat_->streamOff(); };
> > > > > +
> > > > > +		if (useDewarper_) {
> > > > > +			ret = dewarper_->start();
> > > > > +			if (ret) {
> > > > > +				LOG(RkISP1, Error) << "Failed to start dewarper";
> > > > > +				return ret;
> > > > > +			}
> > > > > +		}
> > > > > +		actions += [&]() { dewarper_->stop(); };
> > > > >    	}
> > > > >    	if (data->mainPath_->isEnabled()) {
> > > > > @@ -1000,6 +1063,9 @@ void PipelineHandlerRkISP1::stopDevice(Camera *camera)
> > > > >    		if (ret)
> > > > >    			LOG(RkISP1, Warning)
> > > > >    				<< "Failed to stop parameters for " << camera->id();
> > > > > +
> > > > > +		if (useDewarper_)
> > > > > +			dewarper_->stop();
> > > > >    	}
> > > > >    	ASSERT(data->queuedRequests_.empty());
> > > > > @@ -1110,6 +1176,16 @@ int PipelineHandlerRkISP1::updateControls(RkISP1CameraData *data)
> > > > >    {
> > > > >    	ControlInfoMap::Map controls;
> > > > > +	if (dewarper_) {
> > > > > +		std::pair<Rectangle, Rectangle> cropLimits =
> > > > > +			dewarper_->inputCropBounds(&data->mainPathStream_);
> > > > > +
> > > > > +		controls[&controls::ScalerCrop] = ControlInfo(cropLimits.first,
> > > > > +							      cropLimits.second,
> > > > > +							      cropLimits.second);
> > > > > +		activeCrop_ = cropLimits.second;
> > > > > +	}
> > > > > +
> > > > I'm a bit uncertain here. The current dewarper kernel driver produces
> > > > quite unexpected and difficult to explain results (modified crop
> > > > rectangle, changed pixel aspect ratio). So to me it feels like we
> > > > shouldn't expose that hardware control directly to the user, but do an
> > > > internal implementation (based on the same libcamera control). Could we
> > > > split just the logic that adds the control into a separate patch?
> > > I don't understand internal implementation based on same libcamera
> > > control? How would that look like?
> > > 
> > > So, you mean to say, we don't feed any scaler crop rectangles from
> > > application, but do it internally ?
> > > 
> > > > Another approach would be to merge it in and improve later. But then we
> > > > might break the interface for users of the feature... I lean towards
> > > > splitting the control and merging the rest. In that case we should
> > > > disable the dewarper by default, as the user has no added benefit
> > > > without the control. Still I think all the plumbing should definitely
> > > > go in.
> > > I don't foresee breaking the interface for users. But there can be
> > > improvements on top of this (for e.g. mapping the V4L2 Selection flags)
> > > and letting the application control that via an interface.
> > > 
> > > https://docs.kernel.org/userspace-api/media/v4l/v4l2-selection-flags.html
> > > 
> > > > >    	/* Add the IPA registered controls to list of camera controls. */
> > > > >    	for (const auto &ipaControl : data->ipaControls_)
> > > > >    		controls[ipaControl.first] = ipaControl.second;
> > > > > @@ -1236,6 +1312,26 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
> > > > >    	stat_->bufferReady.connect(this, &PipelineHandlerRkISP1::statReady);
> > > > >    	param_->bufferReady.connect(this, &PipelineHandlerRkISP1::paramReady);
> > > > > +	/* If dewarper is present, create its instance. */
> > > > > +	DeviceMatch dwp("dw100");
> > > > > +	dwp.add("dw100-source");
> > > > > +	dwp.add("dw100-sink");
> > > > > +
> > > > > +	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
> > > > > +	if (dwpMediaDevice) {
> > > > > +		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
> > > > > +		if (dewarper_->isValid()) {
> > > > > +			dewarper_->outputBufferReady.connect(
> > > > > +				this, &PipelineHandlerRkISP1::dewarpBufferReady);
> > > > > +
> > > > > +			LOG(RkISP1, Info) << "Using DW100 dewarper " << dewarper_->deviceNode();
> > > > > +		} else {
> > > > > +			LOG(RkISP1, Warning) << "Found DW100 dewarper " << dewarper_->deviceNode()
> > > > > +					     << " but invalid";
> > > > > +			dewarper_.reset();
> > > > > +		}
> > > > > +	}
> > > > > +
> > > > >    	/*
> > > > >    	 * Enumerate all sensors connected to the ISP and create one
> > > > >    	 * camera instance for each of them.
> > > > > @@ -1282,7 +1378,7 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
> > > > >    		return;
> > > > >    	const FrameMetadata &metadata = buffer->metadata();
> > > > > -	Request *request = buffer->request();
> > > > > +	Request *request = info->request;
> > > > >    	if (metadata.status != FrameMetadata::FrameCancelled) {
> > > > >    		/*
> > > > > @@ -1304,6 +1400,79 @@ void PipelineHandlerRkISP1::bufferReady(FrameBuffer *buffer)
> > > > >    			info->metadataProcessed = true;
> > > > >    	}
> > > > > +	if (!useDewarper_) {
> > > > > +		completeBuffer(request, buffer);
> > > > > +		tryCompleteRequest(info);
> > > > > +
> > > > > +		return;
> > > > > +	}
> > > > > +
> > > > > +	/* Do not queue cancelled frames to dewarper. */
> > > > > +	if (metadata.status == FrameMetadata::FrameCancelled) {
> > > > > +		/*
> > > > > +		 * i.MX8MP is the only known platform with dewarper. It has
> > > > > +		 * no self path. Hence, only main path buffer completion is
> > > > > +		 * required.
> > > > > +		 *
> > > > > +		 * Also, we cannot completeBuffer(request, buffer) as buffer
> > > > > +		 * here, is an internal buffer (between ISP and dewarper) and
> > > > > +		 * is not associated to the any specific request. The request
> > > > > +		 * buffer associated with main path stream is the one that
> > > > > +		 * is required to be completed (not the internal buffer).
> > > > > +		 */
> > > > > +		for (auto it : request->buffers()) {
> > > > > +			if (it.first == &data->mainPathStream_)
> > > > > +				completeBuffer(request, it.second);
> > > > > +		}
> > > > > +
> > > > > +		tryCompleteRequest(info);
> > > > > +		return;
> > > > > +	}
> > > > > +
> > > > > +	/* Handle scaler crop control. */
> > > > > +	const auto &crop = request->controls().get(controls::ScalerCrop);
> > > > > +	if (crop) {
> > > > > +		Rectangle appliedRect = crop.value();
> > > > > +
> > > > > +		int ret = dewarper_->setInputCrop(&data->mainPathStream_,
> > > > > +						  &appliedRect);
> > > > > +		if (!ret && appliedRect != crop.value()) {
> > > > > +			/*
> > > > > +			 * If the rectangle is changed by setInputCrop on the
> > > > > +			 * dewarper, log a debug message and cache the actual
> > > > > +			 * applied rectangle for metadata reporting.
> > > > > +			 */
> > > > > +			LOG(RkISP1, Debug)
> > > > > +				<< "Applied rectangle " << appliedRect.toString()
> > > > > +				<< " differs from requested " << crop.value().toString();
> > > > > +		}
> > > > > +
> > > > > +		activeCrop_ = appliedRect;
> > > > > +	}
> > > > > +
> > > > > +	/*
> > > > > +	 * Queue input and output buffers to the dewarper. The output
> > > > > +	 * buffers for the dewarper are the buffers of the request, supplied
> > > > > +	 * by the application.
> > > > > +	 */
> > > > > +	int ret = dewarper_->queueBuffers(buffer, request->buffers());
> > > > > +	if (ret < 0)
> > > > > +		LOG(RkISP1, Error) << "Cannot queue buffers to dewarper: "
> > > > > +				   << strerror(-ret);
> > > > > +}
> > > > > +
> > > > > +void PipelineHandlerRkISP1::dewarpBufferReady(FrameBuffer *buffer)
> > > > > +{
> > > > > +	ASSERT(activeCamera_);
> > > > > +	RkISP1CameraData *data = cameraData(activeCamera_);
> > > > > +	Request *request = buffer->request();
> > > > > +
> > > > > +	RkISP1FrameInfo *info = data->frameInfo_.find(buffer->request());
> > > > > +	if (!info)
> > > > > +		return;
> > > > > +
> > > > > +	request->metadata().set(controls::ScalerCrop, activeCrop_.value());
> > > > I couldn't easily see if there are cases where more than one buffer are
> > > > queued to the dewarper. In that case the activeCrop_ could be the one
> > > > applied to the next frame. If it is ensured that that is not the case it
> > > > might be worth a comment.
> > > > 
> > > > > +
> > > > >    	completeBuffer(request, buffer);
> > > > >    	tryCompleteRequest(info);
> > > > >    }
>