libcamera: camera_sensor: Expose the Bayer order

Pipeline handlers may need to know the Bayer order produced by the
sensor when a Transform is applied (horizontal or vertical flip). This
is currently implemented manually in the Raspberry Pi pipeline handler.
Move the implementation to the CameraSensor class to make it usable in
other pipeline handlers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>

1 files changed, 35 insertions, 2 deletions

diff --git a/src/libcamera/sensor/camera_sensor.cpp b/src/libcamera/sensor/camera_sensor.cpp
index 40202556..5c4f3532 100644
--- a/src/libcamera/sensor/camera_sensor.cpp
+++ b/src/libcamera/sensor/camera_sensor.cpp
@@ -58,7 +58,7 @@ LOG_DEFINE_CATEGORY(CameraSensor)
 CameraSensor::CameraSensor(const MediaEntity *entity)
 	: entity_(entity), pad_(UINT_MAX), staticProps_(nullptr),
 	  bayerFormat_(nullptr), supportFlips_(false),
-	  properties_(properties::properties)
+	  flipsAlterBayerOrder_(false), properties_(properties::properties)
 {
 }
 
@@ -271,9 +271,14 @@ int CameraSensor::validateSensorDriver()
 	const struct v4l2_query_ext_ctrl *hflipInfo = subdev_->controlInfo(V4L2_CID_HFLIP);
 	const struct v4l2_query_ext_ctrl *vflipInfo = subdev_->controlInfo(V4L2_CID_VFLIP);
 	if (hflipInfo && !(hflipInfo->flags & V4L2_CTRL_FLAG_READ_ONLY) &&
-	    vflipInfo && !(vflipInfo->flags & V4L2_CTRL_FLAG_READ_ONLY))
+	    vflipInfo && !(vflipInfo->flags & V4L2_CTRL_FLAG_READ_ONLY)) {
 		supportFlips_ = true;
 
+		if (hflipInfo->flags & V4L2_CTRL_FLAG_MODIFY_LAYOUT ||
+		    vflipInfo->flags & V4L2_CTRL_FLAG_MODIFY_LAYOUT)
+			flipsAlterBayerOrder_ = true;
+	}
+
 	if (!supportFlips_)
 		LOG(CameraSensor, Debug)
 			<< "Camera sensor does not support horizontal/vertical flip";
@@ -1042,6 +1047,34 @@ Transform CameraSensor::computeTransform(Orientation *orientation) const
 }
 
 /**
+ * \brief Compute the Bayer order that results from the given Transform
+ * \param[in] t The Transform to apply to the sensor
+ *
+ * Some sensors change their Bayer order when they are h-flipped or v-flipped.
+ * This function computes and returns the Bayer order that would result from the
+ * given transform applied to the sensor.
+ *
+ * This function is valid only when the sensor produces raw Bayer formats.
+ *
+ * \return The Bayer order produced by the sensor when the Transform is applied
+ */
+BayerFormat::Order CameraSensor::bayerOrder(Transform t) const
+{
+	/* Return a defined by meaningless value for non-Bayer sensors. */
+	if (!bayerFormat_)
+		return BayerFormat::Order::BGGR;
+
+	if (!flipsAlterBayerOrder_)
+		return bayerFormat_->order;
+
+	/*
+	 * Apply the transform to the native (i.e. untransformed) Bayer order,
+	 * using the rest of the Bayer format supplied by the caller.
+	 */
+	return bayerFormat_->transform(t).order;
+}
+
+/**
  * \brief Retrieve the supported V4L2 controls and their information
  *
  * Control information is updated automatically to reflect the current sensor