various: encapsulate all code in the olive namespace to avoid name collisions

Large-scale code cleanup. Also adds a license to the top of all files that were
missing it.

app/codec/ffmpeg/ffmpegencoder.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 FFMPEGENCODER_H
 #define FFMPEGENCODER_H
 
@@ -10,6 +30,8 @@ extern "C" {
 
 #include "codec/encoder.h"
 
+OLIVE_NAMESPACE_ENTER
+
 class FFmpegEncoder : public Encoder
 {
   Q_OBJECT
@@ -17,7 +39,7 @@ public:
   FFmpegEncoder(const EncodingParams &params);
 
 public slots:
-  virtual void WriteAudio(const AudioRenderingParams& pcm_info, const QString& pcm_filename, const TimeRange &range) override;
+  virtual void WriteAudio(OLIVE_NAMESPACE::AudioRenderingParams pcm_info, const QString& pcm_filename, OLIVE_NAMESPACE::TimeRange range) override;
 
 protected:
   virtual bool OpenInternal() override;
@@ -66,4 +88,6 @@ private:
 
 };
 
+OLIVE_NAMESPACE_EXIT
+
 #endif // FFMPEGENCODER_H