New way of checking for 2D content mislabelled as 3D (#1565).

[dcpomatic.git] / src / lib / frame_interval_checker.h

diff --git a/src/lib/frame_interval_checker.h b/src/lib/frame_interval_checker.h
new file mode 100644 (file)
index 0000000..14b715c
--- /dev/null
+++ b/src/lib/frame_interval_checker.h
@@ -0,0 +1,50 @@
+/*
+    Copyright (C) 2020 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic 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 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic 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 DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#include "dcpomatic_time.h"
+#include <boost/optional.hpp>
+#include <boost/noncopyable.hpp>
+#include <vector>
+
+class FrameIntervalChecker : public boost::noncopyable
+{
+public:
+       void feed (ContentTime time, double frame_rate);
+
+       enum Guess
+       {
+               AGAIN,
+               PROBABLY_3D,
+               PROBABLY_NOT_3D
+       };
+
+       Guess guess () const;
+
+private:
+       boost::optional<ContentTime> _last;
+       /** Intervals of last frames, in fractions of a frame; i.e. 1 in here
+        *  means the last two frames were one frame interval apart according
+        *  to the frame rate passed to ::feed().
+        */
+       std::vector<double> _intervals;
+
+       static int const _frames;
+};
+