diff --git a/app/rational.cpp b/app/rational.cpp
index e6df7a871..e60e2c113 100644
--- a/app/rational.cpp
+++ b/app/rational.cpp
@@ -1,3 +1,23 @@
+/***
+
+  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/>.
+
+***/
+
 #include "rational.h"
 
 rational::rational(const int64_t &numerator) :
diff --git a/app/rational.h b/app/rational.h
index 4a314757c..c545d1fa7 100644
--- a/app/rational.h
+++ b/app/rational.h
@@ -1,3 +1,23 @@
+/***
+
+  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 RATIONAL_H
 #define RATIONAL_H
 
@@ -5,10 +25,21 @@
 
 #include <iostream>
 
+/**
+ * Including AVFormat to support converting from AVRational to Olive's rational class
+ */
 extern "C" {
   #include <libavformat/avformat.h>
 }
 
+/**
+ * @brief The Rational class
+ *
+ * A rational (numerator/denominator) class with C++ operations built in for ease of use.
+ *
+ * Rationals in Olive most frequently represent timing information to easily handle timing in various different
+ * frame/sample rates without the inaccuracy/rounding errors of a floating point type.
+ */
 class rational {
 public:
   // Constructors
diff --git a/app/widget/viewer/viewer.h b/app/widget/viewer/viewer.h
index 28e129180..fa2a5d0b8 100644
--- a/app/widget/viewer/viewer.h
+++ b/app/widget/viewer/viewer.h
@@ -1,3 +1,23 @@
+/***
+
+  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 VIEWER_WIDGET_H
 #define VIEWER_WIDGET_H