[libcamera-devel] [PATCH] libcamera: ipu3: Add rotation to ipu3 pipeline

Fabian Wüthrich me at fabwu.ch
Mon Jan 11 16:21:49 CET 2021


Hi Jacopo

Thanks for your review. 

On 07.01.21 18:33, Jacopo Mondi wrote:
> Hi Fabian
> 
> On Wed, Jan 06, 2021 at 02:35:13PM +0100, Fabian Wüthrich wrote:
>> Use the same transformation logic as in the raspberry pipeline to
>> implement rotations in the ipu3 pipeline.
>>
>> Tested on a Surface Book 2 with an experimental driver for OV5693.
>>
>> Signed-off-by: Fabian Wüthrich <me at fabwu.ch>
>> ---
>>  src/libcamera/pipeline/ipu3/ipu3.cpp | 76 +++++++++++++++++++++++++++-
>>  1 file changed, 74 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
>> index f1151733..76d75a74 100644
>> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
>> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
>> @@ -14,6 +14,7 @@
>>  #include <libcamera/camera.h>
>>  #include <libcamera/control_ids.h>
>>  #include <libcamera/formats.h>
>> +#include <libcamera/property_ids.h>
>>  #include <libcamera/request.h>
>>  #include <libcamera/stream.h>
>>
>> @@ -62,6 +63,12 @@ public:
>>  	Stream outStream_;
>>  	Stream vfStream_;
>>  	Stream rawStream_;
>> +
>> +	/*
>> +	 * Manage horizontal and vertical flips supported (or not) by the
>> +	 * sensor.
>> +	 */
>> +	bool supportsFlips_;
>>  };
>>
>>  class IPU3CameraConfiguration : public CameraConfiguration
>> @@ -74,6 +81,9 @@ public:
>>  	const StreamConfiguration &cio2Format() const { return cio2Configuration_; }
>>  	const ImgUDevice::PipeConfig imguConfig() const { return pipeConfig_; }
>>
>> +	/* Cache the combinedTransform_ that will be applied to the sensor */
>> +	Transform combinedTransform_;
>> +
>>  private:
>>  	/*
>>  	 * The IPU3CameraData instance is guaranteed to be valid as long as the
>> @@ -143,11 +153,54 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
>>  	if (config_.empty())
>>  		return Invalid;
>>
>> -	if (transform != Transform::Identity) {
>> -		transform = Transform::Identity;
>> +	int32_t rotation = data_->cio2_.sensor()->properties().get(properties::Rotation);
>> +	bool success;
>> +	Transform rotationTransform = transformFromRotation(rotation, &success);
> 
> Can you cache this in CameraData ?
> At registerCamera() time we initialize the properties so we can cache
> the above 'rotationTransform' just after
> 
> 		/* Initialize the camera properties. */
> 		data->properties_ = cio2->sensor()->properties();
> 
> Instead of re-calculating it every validation.
> 

Done

>> +	if (!success)
>> +		LOG(IPU3, Warning) << "Invalid rotation of " << rotation << " degrees - ignoring";
>> +	Transform combined = transform * rotationTransform;
>> +
>> +	/*
>> +	 * We combine the platform and user transform, but must "adjust away"
>> +	 * any combined result that includes a transform, as we can't do those.
>> +	 * In this case, flipping only the transpose bit is helpful to
>> +	 * applications - they either get the transform they requested, or have
>> +	 * to do a simple transpose themselves (they don't have to worry about
>> +	 * the other possible cases).
>> +	 */
> 
> The 'rotationTransform' obtained by inspecting the sensor rotation
> does not contain  any Transpose, looking at
> Transform::transformFromRotation().
> 
> Can you address the transpose directly in the
> CameraConfiguration::transpose field before multiplying it by
> rotationTransform ?
> 

I copied the code from the raspberry pipeline (see 
src/libcamera/pipeline/raspberrypi/raspberrypi.cpp line 287 ff.) and
assumed that this is the correct way to handle transpositions.

Should I just flip the transpose bit of CameraConfiguration::transpose
and then combine it with the sensor rotation?

And if so should I send a patch for the raspberry pipeline as well?

>> +	if (!!(combined & Transform::Transpose)) {
>> +		/*
>> +		 * Flipping the transpose bit in "transform" flips it in the
>> +		 * combined result too (as it's the last thing that happens),
>> +		 * which is of course clearing it.
>> +		 */
>> +		transform ^= Transform::Transpose;
>> +		combined &= ~Transform::Transpose;
>>  		status = Adjusted;
>>  	}
>>
>> +	/*
>> +	 * We also check if the sensor doesn't do h/vflips at all, in which
>> +	 * case we clear them, ad the application will have to do everything.
> 
> s/ad/and
> 

Done

>> +	 */
>> +	if (!data_->supportsFlips_ && !!combined) {
>> +		/*
>> +		 * If the sensor can do no transforms, then combined must be
>> +		 * changed to the identity. The only user transform that gives
>> +		 * rise to this the inverse of the rotation. (Recall that
> 
> s/this the/this is the/
> 

Done

>> +		 * combined = transform * rotationTransform.)
>> +		 */
>> +		transform = -rotationTransform;
>> +		combined = Transform::Identity;
>> +		status = Adjusted;
>> +	}
>> +
>> +	/*
>> +	 * Store the final combined transform that configure() will need to
>> +	 * apply to the sensor to save us working it out again.
>> +	 */
>> +	combinedTransform_ = combined;
>> +
>>  	/* Cap the number of entries to the available streams. */
>>  	if (config_.size() > IPU3_MAX_STREAMS) {
>>  		config_.resize(IPU3_MAX_STREAMS);
>> @@ -540,6 +593,19 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
>>  		return ret;
>>  	}
>>
>> +	/*
>> +	 * Configure the H/V flip controls based on the combination of
>> +	 * the sensor and user transform.
>> +	 */
>> +	if (data->supportsFlips_) {
>> +		ctrls = cio2->sensor()->controls();
> 
> I would not re-use ctrls, or rather we should probably:
> 
> --- a/include/libcamera/controls.h
> +++ b/include/libcamera/controls.h
> @@ -352,7 +352,7 @@ private:
>  public:
>         ControlList();
>         ControlList(const ControlIdMap &idmap, ControlValidator *validator = nullptr);
> -       ControlList(const ControlInfoMap &infoMap, ControlValidator *validator = nullptr);
> +       explicit ControlList(const ControlInfoMap &infoMap, ControlValidator *validator = nullptr);
> 
> to avoid this assignment. But maybe it's just me
> 

I created a sensor_ctrls variable to prevent the re-use.

> Thanks
>    j
> 
>> +		ctrls.set(V4L2_CID_HFLIP,
>> +			  static_cast<int32_t>(!!(config->combinedTransform_ & Transform::HFlip)));
>> +		ctrls.set(V4L2_CID_VFLIP,
>> +			  static_cast<int32_t>(!!(config->combinedTransform_ & Transform::VFlip)));
>> +		cio2->sensor()->setControls(&ctrls);
>> +	}
>> +
>>  	return 0;
>>  }
>>
>> @@ -779,6 +845,12 @@ int PipelineHandlerIPU3::registerCameras()
>>  		/* Initialze the camera controls. */
>>  		data->controlInfo_ = IPU3Controls;
>>
>> +		ControlList ctrls = cio2->sensor()->getControls({ V4L2_CID_HFLIP });
>> +		if (!ctrls.empty()) {
>> +			/* We assume it will support vflips too... */
>> +			data->supportsFlips_ = true;
>> +		}
>> +
>>  		/**
>>  		 * \todo Dynamically assign ImgU and output devices to each
>>  		 * stream and camera; as of now, limit support to two cameras
>> --
>> 2.30.0
>>
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>> libcamera-devel at lists.libcamera.org
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