@@ -31,6 +31,9 @@
using namespace libcamera;
+/**
+ * \brief Custom QEvent to signal capture completion
+ */
class CaptureEvent : public QEvent
{
public:
@@ -51,6 +54,10 @@ MainWindow::MainWindow(CameraManager *cm, const OptionsParser::Options &options)
{
int ret;
+ /*
+ * Initialize the UI: Create the toolbar, set the window title and
+ * create the viewfinder widget.
+ */
createToolbars();
title_ = "QCam " + QString::fromStdString(CameraManager::version());
@@ -61,6 +68,7 @@ MainWindow::MainWindow(CameraManager *cm, const OptionsParser::Options &options)
setCentralWidget(viewfinder_);
adjustSize();
+ /* Open the camera and start capture. */
ret = openCamera();
if (ret < 0)
quit();
@@ -96,13 +104,14 @@ int MainWindow::createToolbars()
/* Disable right click context menu. */
toolbar_->setContextMenuPolicy(Qt::PreventContextMenu);
+ /* Quit action. */
action = toolbar_->addAction(QIcon::fromTheme("application-exit",
QIcon(":x-circle.svg")),
"Quit");
action->setShortcut(Qt::CTRL | Qt::Key_Q);
connect(action, &QAction::triggered, this, &MainWindow::quit);
- /* Camera selection. */
+ /* Camera selector. */
QComboBox *cameraCombo = new QComboBox();
connect(cameraCombo, QOverload<int>::of(&QComboBox::activated),
this, &MainWindow::switchCamera);
@@ -114,6 +123,7 @@ int MainWindow::createToolbars()
toolbar_->addSeparator();
+ /* Start/Stop action. */
iconPlay_ = QIcon::fromTheme("media-playback-start",
QIcon(":play-circle.svg"));
iconStop_ = QIcon::fromTheme("media-playback-stop",
@@ -125,6 +135,7 @@ int MainWindow::createToolbars()
connect(action, &QAction::toggled, this, &MainWindow::toggleCapture);
startStopAction_ = action;
+ /* Save As... action. */
action = toolbar_->addAction(QIcon::fromTheme("document-save-as",
QIcon(":save.svg")),
"Save As...");
@@ -142,6 +153,7 @@ void MainWindow::quit()
void MainWindow::updateTitle()
{
+ /* Calculate the average frame rate over the last period. */
unsigned int duration = frameRateInterval_.elapsed();
unsigned int frames = framesCaptured_ - previousFrames_;
double fps = frames * 1000.0 / duration;
@@ -153,8 +165,13 @@ void MainWindow::updateTitle()
setWindowTitle(title_ + " : " + QString::number(fps, 'f', 2) + " fps");
}
+/* -----------------------------------------------------------------------------
+ * Camera Selection
+ */
+
void MainWindow::switchCamera(int index)
{
+ /* Get and acquire the new camera. */
const auto &cameras = cm_->cameras();
if (static_cast<unsigned int>(index) >= cameras.size())
return;
@@ -168,6 +185,10 @@ void MainWindow::switchCamera(int index)
std::cout << "Switching to camera " << cam->name() << std::endl;
+ /*
+ * Stop the capture session, release the current camera, replace it with
+ * the new camera and start a new capture session.
+ */
startStopAction_->setChecked(false);
camera_->release();
@@ -181,9 +202,11 @@ std::string MainWindow::chooseCamera()
QStringList cameras;
bool result;
+ /* If only one camera is available, use it automatically. */
if (cm_->cameras().size() == 1)
return cm_->cameras()[0]->name();
+ /* Present a dialog box to pick a camera. */
for (const std::shared_ptr<Camera> &cam : cm_->cameras())
cameras.append(QString::fromStdString(cam->name()));
@@ -200,6 +223,10 @@ int MainWindow::openCamera()
{
std::string cameraName;
+ /*
+ * Use the camera specified on the command line, if any, or display the
+ * camera selection dialog box otherwise.
+ */
if (options_.isSet(OptCamera))
cameraName = static_cast<std::string>(options_[OptCamera]);
else
@@ -208,6 +235,7 @@ int MainWindow::openCamera()
if (cameraName == "")
return -EINVAL;
+ /* Get and acquire the camera. */
camera_ = cm_->get(cameraName);
if (!camera_) {
std::cout << "Camera " << cameraName << " not found"
@@ -226,6 +254,10 @@ int MainWindow::openCamera()
return 0;
}
+/* -----------------------------------------------------------------------------
+ * Capture Start & Stop
+ */
+
void MainWindow::toggleCapture(bool start)
{
if (start) {
@@ -239,10 +271,16 @@ void MainWindow::toggleCapture(bool start)
}
}
+/**
+ * \brief Start capture with the current camera
+ *
+ * This function shall not be called directly, use toggleCapture() instead.
+ */
int MainWindow::startCapture()
{
int ret;
+ /* Configure the camera. */
config_ = camera_->generateConfiguration({ StreamRole::Viewfinder });
StreamConfiguration &cfg = config_->at(0);
@@ -279,6 +317,7 @@ int MainWindow::startCapture()
return ret;
}
+ /* Configure the viewfinder. */
Stream *stream = cfg.stream();
ret = viewfinder_->setFormat(cfg.pixelFormat,
QSize(cfg.size.width, cfg.size.height));
@@ -289,6 +328,7 @@ int MainWindow::startCapture()
adjustSize();
+ /* Allocate buffers and requests. */
allocator_ = new FrameBufferAllocator(camera_);
ret = allocator_->allocate(stream);
if (ret < 0) {
@@ -321,6 +361,7 @@ int MainWindow::startCapture()
std::make_pair(memory, plane.length);
}
+ /* Start the title timer and the camera. */
titleTimer_.start(2000);
frameRateInterval_.start();
previousFrames_ = 0;
@@ -335,6 +376,7 @@ int MainWindow::startCapture()
camera_->requestCompleted.connect(this, &MainWindow::requestComplete);
+ /* Queue all requests. */
for (Request *request : requests) {
ret = camera_->queueRequest(request);
if (ret < 0) {
@@ -368,6 +410,12 @@ error:
return ret;
}
+/**
+ * \brief Stop ongoing capture
+ *
+ * This function may be called directly when tearing down the MainWindow. Use
+ * toggleCapture() instead in all other cases.
+ */
void MainWindow::stopCapture()
{
if (!isCapturing_)
@@ -403,6 +451,10 @@ void MainWindow::stopCapture()
setWindowTitle(title_);
}
+/* -----------------------------------------------------------------------------
+ * Image Save
+ */
+
void MainWindow::saveImageAs()
{
QImage image = viewfinder_->getCurrentImage();
@@ -418,11 +470,20 @@ void MainWindow::saveImageAs()
writer.write(image);
}
+/* -----------------------------------------------------------------------------
+ * Request Completion Handling
+ */
+
void MainWindow::requestComplete(Request *request)
{
if (request->status() == Request::RequestCancelled)
return;
+ /*
+ * We're running in the libcamera thread context, expensive operations
+ * are not allowed. Add the buffer to the done queue and post a
+ * CaptureEvent for the application thread to handle.
+ */
const std::map<Stream *, FrameBuffer *> &buffers = request->buffers();
FrameBuffer *buffer = buffers.begin()->second;
@@ -436,6 +497,11 @@ void MainWindow::requestComplete(Request *request)
void MainWindow::processCapture()
{
+ /*
+ * Retrieve the next buffer from the done queue. The queue may be empty
+ * if stopCapture() has been called while a CaptureEvent was posted but
+ * not processed yet. Return immediately in that case.
+ */
FrameBuffer *buffer;
{
@@ -460,6 +526,7 @@ void MainWindow::processCapture()
<< " fps: " << std::fixed << std::setprecision(2) << fps
<< std::endl;
+ /* Display the buffer and requeue it to the camera. */
display(buffer);
queueRequest(buffer);
@@ -57,6 +57,7 @@ private Q_SLOTS:
private:
int createToolbars();
+
std::string chooseCamera();
int openCamera();
@@ -68,34 +69,37 @@ private:
int display(FrameBuffer *buffer);
void queueRequest(FrameBuffer *buffer);
+ /* UI elements */
+ QToolBar *toolbar_;
+ QAction *startStopAction_;
+ ViewFinder *viewfinder_;
+
QIcon iconPlay_;
QIcon iconStop_;
QString title_;
QTimer titleTimer_;
+ /* Options */
const OptionsParser::Options &options_;
+ /* Camera manager, camera, configuration and buffers */
CameraManager *cm_;
std::shared_ptr<Camera> camera_;
FrameBufferAllocator *allocator_;
- bool isCapturing_;
std::unique_ptr<CameraConfiguration> config_;
+ std::map<int, std::pair<void *, unsigned int>> mappedBuffers_;
- uint64_t lastBufferTime_;
+ /* Capture state, buffers queue and statistics */
+ bool isCapturing_;
+ QQueue<FrameBuffer *> doneQueue_;
+ QMutex mutex_; /* Protects doneQueue_ */
+ uint64_t lastBufferTime_;
QElapsedTimer frameRateInterval_;
uint32_t previousFrames_;
uint32_t framesCaptured_;
-
- QMutex mutex_;
- QQueue<FrameBuffer *> doneQueue_;
-
- QToolBar *toolbar_;
- QAction *startStopAction_;
- ViewFinder *viewfinder_;
- std::map<int, std::pair<void *, unsigned int>> mappedBuffers_;
};
#endif /* __QCAM_MAIN_WINDOW__ */