[libcamera-devel] [PATCH v3 3/6] libcamera: camera_sensor: Default selection targets

[Jacopo Mondi]

Support for the V4L2 selection API is optional in the CameraSensor
class. Currently the properties registred by using values read
through that API are defaulted in several places (the Android camera HAL
or the CameraSensor class).

In future support for the selection API will be made mandatory, but to
give time to sensor drivers in all test platforms to be updated, provide
a default for each of those properties, simplifying the creation of
the camera sensor properties list and of CameraSensorInfo.

Provide a default size of [2592x2944] for the pixel array size and a
default rectangle [16, 12, 2560, 1920] for the active area and analog
crop rectangles.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 include/libcamera/internal/camera_sensor.h |  3 +
 src/libcamera/camera_sensor.cpp            | 71 +++++++++-------------
 2 files changed, 31 insertions(+), 43 deletions(-)

diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
index aee10aa6e3c7..c2d620f05b65 100644
--- a/include/libcamera/internal/camera_sensor.h
+++ b/include/libcamera/internal/camera_sensor.h
@@ -84,6 +84,9 @@ private:
 	std::vector<unsigned int> mbusCodes_;
 	std::vector<Size> sizes_;
 
+	Size pixelArraySize_;
+	Rectangle activeAreaSize_;
+
 	ControlList properties_;
 };
 
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index a1f1256bd6f4..2ce19a40b448 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -31,6 +31,9 @@ namespace libcamera {
 
 LOG_DEFINE_CATEGORY(CameraSensor)
 
+static constexpr Size defaultPixelArraySize = { 2592, 1944 };
+static constexpr Rectangle defaultActiveAreaSize = { 16, 12, 2560, 1920 };
+
 /**
  * \struct CameraSensorInfo
  * \brief Report the image sensor characteristics
@@ -266,25 +269,35 @@ int CameraSensor::validateSensorDriver()
 	 * but some properties and features, like constructing a
 	 * CameraSensorInfo for the IPA module, won't be supported.
 	 */
+
 	Rectangle rect;
 	int ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP_BOUNDS, &rect);
 	if (ret) {
 		LOG(CameraSensor, Info)
-			<< "Failed to retrieve the readable pixel area size";
+			<< "The PixelArraySize property has been defaulted to: "
+			<< defaultPixelArraySize.toString();
+		rect.width = defaultPixelArraySize.width;
+		rect.height = defaultPixelArraySize.height;
 		err = -EINVAL;
 	}
+	pixelArraySize_.width = rect.width;
+	pixelArraySize_.height = rect.height;
 
 	ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP_DEFAULT, &rect);
 	if (ret) {
 		LOG(CameraSensor, Info)
-			<< "Failed to retrieve the active pixel area size";
+			<< "The PixelArraySize property has been defaulted to: "
+			<< defaultActiveAreaSize.toString();
+		rect = defaultActiveAreaSize;
 		err = -EINVAL;
 	}
+	activeAreaSize_ = rect;
 
 	ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP, &rect);
 	if (ret) {
 		LOG(CameraSensor, Info)
-			<< "Failed to retreive the sensor crop rectangle";
+			<< "The analog crop rectangle has been defaulted to: "
+			<< defaultActiveAreaSize.toString();
 		err = -EINVAL;
 	}
 
@@ -378,30 +391,8 @@ int CameraSensor::initProperties()
 	}
 	properties_.set(properties::Rotation, propertyValue);
 
-	Rectangle bounds;
-	ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP_BOUNDS, &bounds);
-	if (!ret)
-		properties_.set(properties::PixelArraySize, bounds.size());
-	else
-		LOG(CameraSensor, Debug)
-			<< "PixelArraySize property not registered";
-
-	Rectangle crop;
-	ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP_DEFAULT, &crop);
-	if (!ret) {
-		/*
-		 * V4L2_SEL_TGT_CROP_DEFAULT and V4L2_SEL_TGT_CROP_BOUNDS are
-		 * defined relatively to the sensor full pixel array size,
-		 * while properties::PixelArrayActiveAreas is defined relatively
-		 * to properties::PixelArraySize. Adjust it.
-		 */
-		crop.x -= bounds.x;
-		crop.y -= bounds.y;
-		properties_.set(properties::PixelArrayActiveAreas, { crop });
-	} else {
-		LOG(CameraSensor, Debug)
-			<< "PixelArrayActiveAreas property not registered";
-	}
+	properties_.set(properties::PixelArraySize, pixelArraySize_);
+	properties_.set(properties::PixelArrayActiveAreas, { activeAreaSize_ });
 
 	/* Color filter array pattern, register only for RAW sensors. */
 	for (const auto &format : formats_) {
@@ -657,21 +648,15 @@ int CameraSensor::sensorInfo(CameraSensorInfo *info) const
 {
 	info->model = model();
 
-	/* Get the active area size. */
-	Rectangle rect;
-	int ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP_DEFAULT, &rect);
-	if (ret) {
-		LOG(CameraSensor, Error) << "Failed to get the active area";
-		return ret;
-	}
-	info->activeAreaSize = { rect.width, rect.height };
+	/*
+	 * The active area size is a static property, while the crop
+	 * rectangle needs to be re-read as it changes per-mode.
+	 */
+	info->activeAreaSize = { activeAreaSize_.width, activeAreaSize_.height };
 
-	/* It's mandatory for the subdevice to report its crop rectangle. */
-	ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP, &info->analogCrop);
-	if (ret) {
-		LOG(CameraSensor, Error) << "Failed to get the crop rectangle";
-		return ret;
-	}
+	int ret = subdev_->getSelection(pad_, V4L2_SEL_TGT_CROP, &info->analogCrop);
+	if (ret)
+		info->analogCrop = defaultActiveAreaSize;
 
 	/*
 	 * CameraSensorInfo::analogCrop::x and CameraSensorInfo::analogCrop::y
@@ -680,8 +665,8 @@ int CameraSensor::sensorInfo(CameraSensorInfo *info) const
 	 *
 	 * Compensate it by subtracting the active areas offset.
 	 */
-	info->analogCrop.x -= rect.x;
-	info->analogCrop.y -= rect.y;
+	info->analogCrop.x -= activeAreaSize_.x;
+	info->analogCrop.y -= activeAreaSize_.y;
 
 	/* The bit depth and image size depend on the currently applied format. */
 	V4L2SubdeviceFormat format{};
-- 
2.29.2