[libcamera-devel] [PATCH 2/5] libcamera: raspberrypi: Apply transform and pass through to IPA

[David Plowman]

The user-supplied transform is applied to the camera, taking account
of any pre-existing rotation. It is then also plumbed through to the
IPA so that it will (in a further commit) be able to make use of
it.
---
 include/libcamera/ipa/raspberrypi.h           |  1 +
 src/ipa/raspberrypi/raspberrypi.cpp           | 13 ++++++++-
 .../pipeline/raspberrypi/raspberrypi.cpp      | 27 +++++++++++++++++--
 3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/include/libcamera/ipa/raspberrypi.h b/include/libcamera/ipa/raspberrypi.h
index ca62990..3905a4a 100644
--- a/include/libcamera/ipa/raspberrypi.h
+++ b/include/libcamera/ipa/raspberrypi.h
@@ -14,6 +14,7 @@ enum RPiConfigParameters {
 	RPI_IPA_CONFIG_LS_TABLE = (1 << 0),
 	RPI_IPA_CONFIG_STAGGERED_WRITE = (1 << 1),
 	RPI_IPA_CONFIG_SENSOR = (1 << 2),
+	RPI_IPA_CONFIG_TRANSFORM = (1 << 3),
 };
 
 enum RPiOperations {
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index 3747208..2809521 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -21,6 +21,7 @@
 #include <libcamera/ipa/raspberrypi.h>
 #include <libcamera/request.h>
 #include <libcamera/span.h>
+#include <libcamera/transform.h>
 
 #include <libipa/ipa_interface_wrapper.h>
 
@@ -144,6 +145,9 @@ private:
 	/* LS table allocation passed in from the pipeline handler. */
 	FileDescriptor lsTableHandle_;
 	void *lsTable_;
+
+	/* This is the transform requested by the user/application driving libcamera. */
+	Transform userTransform_;
 };
 
 int IPARPi::init(const IPASettings &settings)
@@ -282,6 +286,7 @@ void IPARPi::configure(const CameraSensorInfo &sensorInfo,
 	lastMode_ = mode_;
 
 	/* Store the lens shading table pointer and handle if available. */
+	unsigned int next_element = 0;
 	if (ipaConfig.operation & RPI_IPA_CONFIG_LS_TABLE) {
 		/* Remove any previous table, if there was one. */
 		if (lsTable_) {
@@ -290,7 +295,7 @@ void IPARPi::configure(const CameraSensorInfo &sensorInfo,
 		}
 
 		/* Map the LS table buffer into user space. */
-		lsTableHandle_ = FileDescriptor(ipaConfig.data[0]);
+		lsTableHandle_ = FileDescriptor(ipaConfig.data[next_element++]);
 		if (lsTableHandle_.isValid()) {
 			lsTable_ = mmap(nullptr, MAX_LS_GRID_SIZE, PROT_READ | PROT_WRITE,
 					MAP_SHARED, lsTableHandle_.fd(), 0);
@@ -301,6 +306,12 @@ void IPARPi::configure(const CameraSensorInfo &sensorInfo,
 			}
 		}
 	}
+
+	/* Fish out any transform set by the user/application. */
+	if (ipaConfig.operation & RPI_IPA_CONFIG_TRANSFORM) {
+		uint32_t transformType = ipaConfig.data[next_element++];
+		userTransform_ = reinterpret_cast<Transform &>(transformType);
+	}
 }
 
 void IPARPi::mapBuffers(const std::vector<IPABuffer> &buffers)
diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index 82a0a4d..5fb427a 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -324,6 +324,9 @@ public:
 	uint32_t expectedSequence_;
 	bool sensorMetadata_;
 
+	/* This is the transform requested by the user/application driving libcamera. */
+	Transform userTransform_;
+
 	/*
 	 * All the functions in this class are called from a single calling
 	 * thread. So, we do not need to have any mutex to protect access to any
@@ -400,6 +403,9 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
 	if (config_.empty())
 		return Invalid;
 
+	if (userTransform.contains(Transform::transpose()))
+		return Invalid;
+
 	unsigned int rawCount = 0, outCount = 0, count = 0, maxIndex = 0;
 	std::pair<int, Size> outSize[2];
 	Size maxSize;
@@ -609,6 +615,9 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
 	unsigned int maxIndex = 0;
 	bool rawStream = false;
 
+	/* Record the transform requested by the application. */
+	data->userTransform_ = config->userTransform;
+
 	/*
 	 * Look for the RAW stream (if given) size as well as the largest
 	 * ISP output size.
@@ -1140,6 +1149,11 @@ int RPiCameraData::configureIPA()
 		ipaConfig.data = { static_cast<unsigned int>(lsTable_.fd()) };
 	}
 
+	/* We must pass the user transform to the IPA too. */
+	uint32_t transformType = reinterpret_cast<uint32_t &>(userTransform_);
+	ipaConfig.operation |= RPI_IPA_CONFIG_TRANSFORM;
+	ipaConfig.data.push_back(transformType);
+
 	CameraSensorInfo sensorInfo = {};
 	int ret = sensor_->sensorInfo(&sensorInfo);
 	if (ret) {
@@ -1168,8 +1182,17 @@ int RPiCameraData::configureIPA()
 		/* Configure the H/V flip controls based on the sensor rotation. */
 		ControlList ctrls(unicam_[Unicam::Image].dev()->controls());
 		int32_t rotation = sensor_->properties().get(properties::Rotation);
-		ctrls.set(V4L2_CID_HFLIP, static_cast<int32_t>(!!rotation));
-		ctrls.set(V4L2_CID_VFLIP, static_cast<int32_t>(!!rotation));
+
+		/* The camera needs to compose the user transform with the rotation. */
+		Transform rotationTransform;
+		if (Transform::rotation(rotation, rotationTransform) == false)
+			return -EINVAL;
+		Transform transform = userTransform_ * rotationTransform;
+
+		ctrls.set(V4L2_CID_HFLIP,
+			  static_cast<int32_t>(transform.contains(Transform::hflip())));
+		ctrls.set(V4L2_CID_VFLIP,
+			  static_cast<int32_t>(transform.contains(Transform::vflip())));
 		unicam_[Unicam::Image].dev()->setControls(&ctrls);
 	}
 
-- 
2.20.1