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

[Jacopo Mondi]

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.

> +	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 ?

> +	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

> +	 */
> +	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/

> +		 * 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

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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