src/cam/file_sink.cpp

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2018, Google Inc.
 *
 * camera_manager.h - Camera management
 */

#include <libcamera/camera_manager.h>

#include <condition_variable>
#include <map>

#include <libcamera/camera.h>

#include <libcamera/base/utils.h>

#include <libcamera/base/log.h>
#include <libcamera/base/thread.h>

#include "libcamera/internal/device_enumerator.h"
#include "libcamera/internal/ipa_manager.h"
#include "libcamera/internal/pipeline_handler.h"
#include "libcamera/internal/process.h"

/**
 * \file camera_manager.h
 * \brief The camera manager
 */

/**
 * \brief Top-level libcamera namespace
 */
namespace libcamera {

LOG_DEFINE_CATEGORY(Camera)

class CameraManager::Private : public Extensible::Private, public Thread
{
	LIBCAMERA_DECLARE_PUBLIC(CameraManager)

public:
	Private();

	int start();
	void addCamera(std::shared_ptr<Camera> camera,
		       const std::vector<dev_t> &devnums);
	void removeCamera(Camera *camera);

	/*
	 * This mutex protects
	 *
	 * - initialized_ and status_ during initialization
	 * - cameras_ and camerasByDevnum_ after initialization
	 */
	mutable Mutex mutex_;
	std::vector<std::shared_ptr<Camera>> cameras_;
	std::map<dev_t, std::weak_ptr<Camera>> camerasByDevnum_;

protected:
	void run() override;

private:
	int init();
	void createPipelineHandlers();
	void cleanup();

	std::condition_variable cv_;
	bool initialized_;
	int status_;

	std::unique_ptr<DeviceEnumerator> enumerator_;

	IPAManager ipaManager_;
	ProcessManager processManager_;
};

CameraManager::Private::Private()
	: initialized_(false)
{
}

int CameraManager::Private::start()
{
	int status;

	/* Start the thread and wait for initialization to complete. */
	Thread::start();

	{
		MutexLocker locker(mutex_);
		cv_.wait(locker, [&] { return initialized_; });
		status = status_;
	}

	/* If a failure happened during initialization, stop the thread. */
	if (status < 0) {
		exit();
		wait();
		return status;
	}

	return 0;
}

void CameraManager::Private::run()
{
	LOG(Camera, Debug) << "Starting camera manager";

	int ret = init();

	mutex_.lock();
	status_ = ret;
	initialized_ = true;
	mutex_.unlock();
	cv_.notify_one();

	if (ret < 0)
		return;

	/* Now start processing events and messages. */
	exec();

	cleanup();
}

int CameraManager::Private::init()
{
	enumerator_ = DeviceEnumerator::create();
	if (!enumerator_ || enumerator_->enumerate())
		return -ENODEV;

	createPipelineHandlers();

	return 0;
}

void CameraManager::Private::createPipelineHandlers()
{
	CameraManager *const o = LIBCAMERA_O_PTR();

	/*
	 * \todo Try to read handlers and order from configuration
	 * file and only fallback on all handlers if there is no
	 * configuration file.
	 */
	std::vector<PipelineHandlerFactory *> &factories =
		PipelineHandlerFactory::factories();

	for (PipelineHandlerFactory *factory : factories) {
		LOG(Camera, Debug)
			<< "Found registered pipeline handler '"
			<< factory->name() << "'";
		/*
		 * Try each pipeline handler until it exhaust
		 * all pipelines it can provide.
		 */
		while (1) {
			std::shared_ptr<PipelineHandler> pipe = factory->create(o);
			if (!pipe->match(enumerator_.get()))
				break;

			LOG(Camera, Debug)
				<< "Pipeline handler \"" << factory->name()
				<< "\" matched";
		}
	}

	enumerator_->devicesAdded.connect(this, &Private::createPipelineHandlers);
}

void CameraManager::Private::cleanup()
{
	enumerator_->devicesAdded.disconnect(this, &Private::createPipelineHandlers);

	/*
	 * Release all references to cameras to ensure they all get destroyed
	 * before the device enumerator deletes the media devices. Cameras are
	 * destroyed via Object::deleteLater() API, hence we need to explicitly
	 * process deletion requests from the thread's message queue as the event
	 * loop is not in action here.
	 */
	cameras_.clear();
	dispatchMessages(Message::Type::DeferredDelete);

	enumerator_.reset(nullptr);
}

void CameraManager::Private::addCamera(std::shared_ptr<Camera> camera,
				       const std::vector<dev_t> &devnums)
{
	MutexLocker locker(mutex_);

	for (std::shared_ptr<Camera> c : cameras_) {
		if (c->id() == camera->id()) {
			LOG(Camera, Fatal)
				<< "Trying to register a camera with a duplicated ID '"
				<< camera->id() << "'";
			return;
		}
	}

	cameras_.push_back(std::move(camera));

	unsigned int index = cameras_.size() - 1;
	for (dev_t devnum : devnums)
		camerasByDevnum_[devnum] = cameras_[index];
}

void CameraManager::Private::removeCamera(Camera *camera)
{
	MutexLocker locker(mutex_);

	auto iter = std::find_if(cameras_.begin(), cameras_.end(),
				 [camera](std::shared_ptr<Camera> &c) {
					 return c.get() == camera;
				 });
	if (iter == cameras_.end())
		return;

	LOG(Camera, Debug)
		<< "Unregistering camera '" << camera->id() << "'";

	auto iter_d = std::find_if(camerasByDevnum_.begin(), camerasByDevnum_.end(),
				   [camera](const std::pair<dev_t, std::weak_ptr<Camera>> &p) {
					   return p.second.lock().get() == camera;
				   });
	if (iter_d != camerasByDevnum_.end())
		camerasByDevnum_.erase(iter_d);

	cameras_.erase(iter);
}

/**
 * \class CameraManager
 * \brief Provide access and manage all cameras in the system
 *
 * The camera manager is the entry point to libcamera. It enumerates devices,
 * associates them with pipeline managers, and provides access to the cameras
 * in the system to applications. The manager owns all Camera objects and
 * handles hot-plugging and hot-unplugging to manage the lifetime of cameras.
 *
 * To interact with libcamera, an application starts by creating a camera
 * manager instance. Only a single instance of the camera manager may exist at
 * a time. Attempting to create a second instance without first deleting the
 * existing instance results in undefined behaviour.
 *
 * The manager is initially stopped, and shall be started with start(). This
 * will enumerate all the cameras present in the system, which can then be
 * listed with list() and retrieved with get().
 *
 * Cameras are shared through std::shared_ptr<>, ensuring that a camera will
 * stay valid until the last reference is released without requiring any special
 * action from the application. Once the application has released all the
 * references it held to cameras, the camera manager can be stopped with
 * stop().
 */

CameraManager *CameraManager::self_ = nullptr;

CameraManager::CameraManager()
	: Extensible(std::make_unique<CameraManager::Private>())
{
	if (self_)
		LOG(Camera, Fatal)
			<< "Multiple CameraManager objects are not allowed";

	self_ = this;
}

/**
 * \brief Destroy the camera manager
 *
 * Destroying the camera manager stops it if it is currently running.
 */
CameraManager::~CameraManager()
{
	stop();

	self_ = nullptr;
}

/**
 * \brief Start the camera manager
 *
 * Start the camera manager and enumerate all devices in the system. Once
 * the start has been confirmed the user is free to list and otherwise
 * interact with cameras in the system until either the camera manager
 * is stopped or the camera is unplugged from the system.
 *
 * \return 0 on success or a negative error code otherwise
 */
int CameraManager::start()
{
	LOG(Camera, Info) << "libcamera " << version_;

	int ret = _d()->start();
	if (ret)
		LOG(Camera, Error) << "Failed to start camera manager: "
				   << strerror(-ret);

	return ret;
}

/**
 * \brief Stop the camera manager
 *
 * Before stopping the camera manager the caller is responsible for making
 * sure all cameras provided by the manager are returned to the manager.
 *
 * After the manager has been stopped no resource provided by the camera
 * manager should be consider valid or functional even if they for one
 * reason or another have yet to be deleted.
 */
void CameraManager::stop()
{
	Private *const d = _d();
	d->exit();
	d->wait();
}

/**
 * \fn CameraManager::cameras()
 * \brief Retrieve all available cameras
 *
 * Before calling this function the caller is responsible for ensuring that
 * the camera manager is running.
 *
 * \context This function is \threadsafe.
 *
 * \return List of all available cameras
 */
std::vector<std::shared_ptr<Camera>> CameraManager::cameras() const
{
	const Private *const d = _d();

	MutexLocker locker(d->mutex_);

	return d->cameras_;
}

/**
 * \brief Get a camera based on ID
 * \param[in] id ID of camera to get
 *
 * Before calling this function the caller is responsible for ensuring that
 * the camera manager is running.
 *
 * \context This function is \threadsafe.
 *
 * \return Shared pointer to Camera object or nullptr if camera not found
 */
std::shared_ptr<Camera> CameraManager::get(const std::string &id)
{
	Private *const d = _d();

	MutexLocker locker(d->mutex_);

	for (std::shared_ptr<Camera> camera : d->cameras_) {
		if (camera->id() == id)
			return camera;
	}

	return nullptr;
}

/**
 * \brief Retrieve a camera based on device number
 * \param[in] devnum Device number of camera to get
 *
 * This function is meant solely for the use of the V4L2 compatibility
 * layer, to map device nodes to Camera instances. Applications shall
 * not use it and shall instead retrieve cameras by name.
 *
 * Before calling this function the caller is responsible for ensuring that
 * the camera manager is running.
 *
 * \context This function is \threadsafe.
 *
 * \return Shared pointer to Camera object, which is empty if the camera is
 * not found
 */
std::shared_ptr<Camera> CameraManager::get(dev_t devnum)
{
	Private *const d = _d();

	MutexLocker locker(d->mutex_);

	auto iter = d->camerasByDevnum_.find(devnum);
	if (iter == d->camerasByDevnum_.end())
		return nullptr;

	return iter->second.lock();
}

/**
 * \var CameraManager::cameraAdded
 * \brief Notify of a new camera added to the system
 *
 * This signal is emitted when a new camera is detected and successfully handled
 * by the camera manager. The notification occurs alike for cameras detected
 * when the manager is started with start() or when new cameras are later
 * connected to the system. When the signal is emitted the new camera is already
 * available from the list of cameras().
 *
 * The signal is emitted from the CameraManager thread. Applications shall
 * minimize the time spent in the signal handler and shall in particular not
 * perform any blocking operation.
 */

/**
 * \var CameraManager::cameraRemoved
 * \brief Notify of a new camera removed from the system
 *
 * This signal is emitted when a camera is removed from the system. When the
 * signal is emitted the camera is not available from the list of cameras()
 * anymore.
 *
 * The signal is emitted from the CameraManager thread. Applications shall
 * minimize the time spent in the signal handler and shall in particular not
 * perform any blocking operation.
 */

/**
 * \brief Add a camera to the camera manager
 * \param[in] camera The camera to be added
 * \param[in] devnums The device numbers to associate with \a camera
 *
 * This function is called by pipeline handlers to register the cameras they
 * handle with the camera manager. Registered cameras are immediately made
 * available to the system.
 *
 * \a devnums are used by the V4L2 compatibility layer to map V4L2 device nodes
 * to Camera instances.
 *
 * \context This function shall be called from the CameraManager thread.
 */
void CameraManager::addCamera(std::shared_ptr<Camera> camera,
			      const std::vector<dev_t> &devnums)
{
	Private *const d = _d();

	ASSERT(Thread::current() == d);

	d->addCamera(camera, devnums);
	cameraAdded.emit(camera);
}

/**
 * \brief Remove a camera from the camera manager
 * \param[in] camera The camera to be removed
 *
 * This function is called by pipeline handlers to unregister cameras from the
 * camera manager. Unregistered cameras won't be reported anymore by the
 * cameras() and get() calls, but references may still exist in applications.
 *
 * \context This function shall be called from the CameraManager thread.
 */
void CameraManager::removeCamera(std::shared_ptr<Camera> camera)
{
	Private *const d = _d();

	ASSERT(Thread::current() == d);

	d->removeCamera(camera.get());
	cameraRemoved.emit(camera);
}

/**
 * \fn const std::string &CameraManager::version()
 * \brief Retrieve the libcamera version string
 * \context This function is \a threadsafe.
 * \return The libcamera version string
 */

} /* namespace libcamera */
Age	Commit message (Collapse)	Author
2021-10-15	cam: Pass stream names to FileSink	Laurent Pinchart
	The FileSink class constructs stream names internally the same way that the CameraSession does, except that it fails to add the camera name. This results in files being written without the camera name. This could be fixed in FileSink, but we would still duplicate code to construct stream names. Pass the stream names map from CameraSession to FileSink instead, and store it internally. Fixes: 02001fecb0f5 ("cam: Turn BufferWriter into a FrameSink") Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-09-07	cam: file_sink: Use Image class to access pixel data	Laurent Pinchart
	Replace the manual implementation of frame buffer mapping with the Image class to improve code sharing. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Hirokazu Honda <hiroh@chromium.org> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-09-07	libcamera: framebuffer: Prevent modifying the number of metadata planes	Laurent Pinchart
	The number of metadata planes should always match the number of frame buffer planes. Enforce this by making the vector private and providing accessor functions. As this changes the public API, update all in-tree users accordingly. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
2021-08-30	cam: file_sink: Use offset in mapping FrameBuffer	Hirokazu Honda
	This fixes the way of mapping FrameBuffer in FrameSink by using offset. Signed-off-by: Hirokazu Honda <hiroh@chromium.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-08-05	cam: Rename BufferWriter to FileSink	Laurent Pinchart
	Rename the BufferWriter class to FileSink to establish a common naming scheme for all sinks. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>