minor comment conformance

app/common/channellayout.h

@@ -1,6 +1,33 @@
+/***
+
+  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 CHANNELLAYOUT_H
 #define CHANNELLAYOUT_H
 
+/**
+ * Channel Layouts header
+ *
+ * We don't do much here at the moment, audio is a much simpler beast than video nowadays and FFmpeg seems to cover it
+ * fairly well.
+ */
+
 extern "C" {
 #include <libavcodec/avcodec.h>
 }