merged encoder and decoder code into one folder since they can share quite a bit of code

app/codec/encoder.cpp

@@ -0,0 +1,79 @@
+#include "encoder.h"
+
+#include "ffmpeg/ffmpegencoder.h"
+
+Encoder::Encoder(const EncodingParams &params) :
+  open_(false),
+  params_(params)
+{
+}
+
+const EncodingParams &Encoder::params() const
+{
+  return params_;
+}
+
+EncodingParams::EncodingParams() :
+  video_enabled_(false),
+  audio_enabled_(false)
+{
+}
+
+void EncodingParams::SetFilename(const QString &filename)
+{
+  filename_ = filename;
+}
+
+void EncodingParams::EnableVideo(const VideoRenderingParams &video_params, const QString &vcodec)
+{
+  video_enabled_ = true;
+  video_params_ = video_params;
+  video_codec_ = vcodec;
+}
+
+void EncodingParams::EnableAudio(const AudioRenderingParams &audio_params, const QString &acodec)
+{
+  audio_enabled_ = true;
+  audio_params_ = audio_params;
+  audio_codec_ = acodec;
+}
+
+const QString &EncodingParams::filename() const
+{
+  return filename_;
+}
+
+bool EncodingParams::video_enabled() const
+{
+  return video_enabled_;
+}
+
+const QString &EncodingParams::video_codec() const
+{
+  return video_codec_;
+}
+
+const VideoRenderingParams &EncodingParams::video_params() const
+{
+  return video_params_;
+}
+
+bool EncodingParams::audio_enabled() const
+{
+  return audio_enabled_;
+}
+
+const QString &EncodingParams::audio_codec() const
+{
+  return audio_codec_;
+}
+
+const AudioRenderingParams &EncodingParams::audio_params() const
+{
+  return audio_params_;
+}
+
+EncoderPtr Encoder::CreateFromID(const QString &id, const EncodingParams& params)
+{
+  return std::make_shared<FFmpegEncoder>(params);
+}