renderer: optimizing and fixing code paths

Re-introducing some old concepts for the new structure.

app/render/backend/renderticket.h

@@ -0,0 +1,94 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
+#ifndef RENDERTICKET_H
+#define RENDERTICKET_H
+
+#include <QWaitCondition>
+
+#include "codec/frame.h"
+#include "codec/samplebuffer.h"
+#include "common/timerange.h"
+
+OLIVE_NAMESPACE_ENTER
+
+class RenderTicket : public QObject
+{
+  Q_OBJECT
+public:
+  enum Type {
+    kTypeVideo,
+    kTypeAudio
+  };
+
+  RenderTicket(Type type, const TimeRange& time);
+
+  const TimeRange& GetTime() const
+  {
+    return time_;
+  }
+
+  Type GetType() const
+  {
+    return type_;
+  }
+
+  void WaitForFinished();
+
+  QVariant Get();
+
+  bool IsFinished(bool lock = true);
+
+  bool WasCancelled();
+
+  QMutex* lock()
+  {
+    return &lock_;
+  }
+
+  void Finish(QVariant result);
+
+  void Cancel();
+
+signals:
+  void Finished();
+
+private:
+  bool finished_;
+
+  bool cancelled_;
+
+  QVariant result_;
+
+  QMutex lock_;
+
+  QWaitCondition wait_;
+
+  TimeRange time_;
+
+  Type type_;
+
+};
+
+using RenderTicketPtr = std::shared_ptr<RenderTicket>;
+
+OLIVE_NAMESPACE_EXIT
+
+#endif // RENDERTICKET_H