UI: Add eRTMP Multitrack Video Output

UI/multitrack-video-error.cpp

@@ -0,0 +1,46 @@
+#include "multitrack-video-error.hpp"
+
+#include <QMessageBox>
+#include "obs-app.hpp"
+
+MultitrackVideoError MultitrackVideoError::critical(QString error)
+{
+	return {Type::Critical, error};
+}
+
+MultitrackVideoError MultitrackVideoError::warning(QString error)
+{
+	return {Type::Warning, error};
+}
+
+MultitrackVideoError MultitrackVideoError::cancel()
+{
+	return {Type::Cancel, {}};
+}
+
+bool MultitrackVideoError::ShowDialog(
+	QWidget *parent, const QString &multitrack_video_name) const
+{
+	QMessageBox mb(parent);
+	mb.setTextFormat(Qt::RichText);
+	mb.setWindowTitle(QTStr("Output.StartStreamFailed"));
+
+	if (type == Type::Warning) {
+		mb.setText(
+			error +
+			QTStr("FailedToStartStream.WarningRetryNonMultitrackVideo")
+				.arg(multitrack_video_name));
+		mb.setIcon(QMessageBox::Warning);
+		mb.setStandardButtons(QMessageBox::StandardButton::Yes |
+				      QMessageBox::StandardButton::No);
+		return mb.exec() == QMessageBox::StandardButton::Yes;
+	} else if (type == Type::Critical) {
+		mb.setText(error);
+		mb.setIcon(QMessageBox::Critical);
+		mb.setStandardButtons(
+			QMessageBox::StandardButton::Ok); // cannot continue
+		mb.exec();
+	}
+
+	return false;
+}