qrcode: Set camera format to avoid issues with unsupported formats

src/QrCodeScannerFilter.cpp

@@ -61,6 +61,18 @@ QVideoFilterRunnable *QrCodeScannerFilter::createFilterRunnable()
 	return new QrCodeScannerFilterRunnable(this);
 }
 
+void QrCodeScannerFilter::setCameraDefaultVideoFormat(QObject *qmlCamera)
+{
+	QCamera *camera = qvariant_cast<QCamera*>(qmlCamera->property("mediaObject"));
+	if (camera) {
+		QCameraViewfinderSettings settings = camera->viewfinderSettings();
+		settings.setPixelFormat(QVideoFrame::Format_RGB24);
+		camera->setViewfinderSettings(settings);
+	} else {
+		qWarning() << "Could not set pixel format of QML camera";
+	}
+}
+
 QrCodeScannerFilterRunnable::QrCodeScannerFilterRunnable(QrCodeScannerFilter *filter)
 	: QObject(nullptr),
 	m_filter(filter)
@@ -97,7 +109,7 @@ void QrCodeScannerFilterRunnable::processVideoFrameProbed(
 		QrCodeScannerFilter *filter
 ) {
 	// Return if the frame is empty.
-	if (videoFrame.data().length() < 1)
+	if (videoFrame.data().isEmpty())
 		return;
 
 	// Create an image from the frame.
@@ -108,7 +120,7 @@ void QrCodeScannerFilterRunnable::processVideoFrameProbed(
 		// dirty hack: write QVideoFrame::PixelFormat as string to format using QDebug
 		//             QMetaEnum::valueToKey() did not work
 		QString format;
-		QDebug(&format) << videoFrame.pixelFormat();
+		QDebug(&format).nospace() << videoFrame.pixelFormat();
 
 		qDebug() << "QrCodeScannerFilterRunnable error: Cannot create image file to process.";
 		qDebug() << "Maybe it was a format conversion problem.";

src/QrCodeScannerFilter.h

@@ -48,7 +48,6 @@ class QrCodeScannerFilter : public QAbstractVideoFilter
 	friend class QrCodeScannerFilterRunnable;
 
 	Q_OBJECT
-	Q_PROPERTY(QrCodeDecoder* decoder READ decoder)
 
 public:
 	/**
@@ -65,6 +64,13 @@ public:
 	QrCodeDecoder *decoder();
 	QVideoFilterRunnable *createFilterRunnable() override;
 
+	/**
+	 * Sets the video frame format of the QML Camera object to our default format
+	 *
+	 * @param qmlCamera Camera object from QML
+	 */
+	Q_INVOKABLE void setCameraDefaultVideoFormat(QObject *qmlCamera);
+
 signals:
 	/**
 	 * Emitted when the scanning of an image did not succeed, i.e. no valid QR code was found.

src/qml/QrCodeScannerPage.qml

@@ -95,5 +95,9 @@ Kirigami.Page {
 			focusMode: Camera.FocusContinuous
 			focusPointMode: Camera.FocusPointCenter
 		}
+
+		Component.onCompleted: {
+			scannerFilter.setCameraDefaultVideoFormat(camera);
+		}
 	}
 }

[Linus Jahn]

Actually it was me committing in JBB's name here...