began base encoder type for abstracting around exporting

Essentially the same principle as Decoders but somewhat different functionality.

app/encoder/encoder.cpp

@@ -0,0 +1,31 @@
+#include "encoder.h"
+
+Encoder::Encoder(const EncodingParams &params) :
+  params_(params)
+{
+}
+
+EncodingParams::EncodingParams() :
+  video_enabled_(false),
+  audio_enabled_(false)
+{
+}
+
+void EncodingParams::SetFilename(const QString &filename)
+{
+  filename_ = filename;
+}
+
+void EncodingParams::EnableVideo(const VideoParams &video_params, const QString &vcodec)
+{
+  video_enabled_ = true;
+  video_params_ = video_params;
+  video_codec_ = vcodec;
+}
+
+void EncodingParams::EnableAudio(const AudioParams &audio_params, const QString &acodec)
+{
+  audio_enabled_ = true;
+  audio_params_ = audio_params;
+  audio_codec_ = acodec;
+}