diff --git a/gtk2_ardour/export_video_dialog.cc b/gtk2_ardour/export_video_dialog.cc
index ce85fad81e..eb4213b237 100644
--- a/gtk2_ardour/export_video_dialog.cc
+++ b/gtk2_ardour/export_video_dialog.cc
@@ -584,7 +584,7 @@ ExportVideoDialog::encode_pass (int pass)
 	}
 
 	std::string preset = preset_combo.get_active_text();
-	FFSettings ffs ; /* = transcoder->default_encoder_settings(); */
+	TranscodeFfmpeg::FFSettings ffs ; /* = transcoder->default_encoder_settings(); */
 	ffs.clear();
 
 	if (fps_checkbox.get_active()) {
@@ -740,7 +740,7 @@ ExportVideoDialog::encode_pass (int pass)
 		transcoder->set_avoffset(av_offset / (double)_session->nominal_frame_rate());
 	}
 
-	FFSettings meta = transcoder->default_meta_data();
+	TranscodeFfmpeg::FFSettings meta = transcoder->default_meta_data();
 	if (meta_checkbox.get_active()) {
 		ARDOUR::SessionMetadata * session_data = ARDOUR::SessionMetadata::Metadata();
 		if (session_data->year() > 0 ) {
diff --git a/gtk2_ardour/transcode_ffmpeg.cc b/gtk2_ardour/transcode_ffmpeg.cc
index 657b79ffba..9499c6c184 100644
--- a/gtk2_ardour/transcode_ffmpeg.cc
+++ b/gtk2_ardour/transcode_ffmpeg.cc
@@ -261,10 +261,10 @@ TranscodeFfmpeg::probe ()
 	return true;
 }
 
-FFSettings
+TranscodeFfmpeg::FFSettings
 TranscodeFfmpeg::default_encoder_settings ()
 {
-	FFSettings ffs;
+	TranscodeFfmpeg::FFSettings ffs;
 	ffs.clear();
 	ffs["-vcodec"] = "mpeg4";
 	ffs["-acodec"] = "ac3";
@@ -273,10 +273,10 @@ TranscodeFfmpeg::default_encoder_settings ()
 	return ffs;
 }
 
-FFSettings
+TranscodeFfmpeg::FFSettings
 TranscodeFfmpeg::default_meta_data ()
 {
-	FFSettings ffm;
+	TranscodeFfmpeg::FFSettings ffm;
 	ffm.clear();
 	ffm["comment"] = "Created with ardour";
 	return ffm;
@@ -308,7 +308,7 @@ TranscodeFfmpeg::format_metadata (std::string key, std::string value)
 }
 
 bool
-TranscodeFfmpeg::encode (std::string outfile, std::string inf_a, std::string inf_v, FFSettings ffs, FFSettings meta, bool map)
+TranscodeFfmpeg::encode (std::string outfile, std::string inf_a, std::string inf_v, TranscodeFfmpeg::FFSettings ffs, TranscodeFfmpeg::FFSettings meta, bool map)
 {
 #define MAX_FFMPEG_ENCODER_ARGS (100)
 	char **argp;
@@ -327,11 +327,11 @@ TranscodeFfmpeg::encode (std::string outfile, std::string inf_a, std::string inf
 	argp[a++] = strdup("-i");
 	argp[a++] = strdup(inf_a.c_str());
 
-	for(FFSettings::const_iterator it = ffs.begin(); it != ffs.end(); ++it) {
+	for(TranscodeFfmpeg::FFSettings::const_iterator it = ffs.begin(); it != ffs.end(); ++it) {
 		argp[a++] = strdup(it->first.c_str());
 		argp[a++] = strdup(it->second.c_str());
 	}
-	for(FFSettings::const_iterator it = meta.begin(); it != meta.end(); ++it) {
+	for(TranscodeFfmpeg::FFSettings::const_iterator it = meta.begin(); it != meta.end(); ++it) {
 		argp[a++] = strdup("-metadata");
 		argp[a++] = format_metadata(it->first.c_str(), it->second.c_str());
 	}
diff --git a/gtk2_ardour/transcode_ffmpeg.h b/gtk2_ardour/transcode_ffmpeg.h
index d1f445bf48..61267ac853 100644
--- a/gtk2_ardour/transcode_ffmpeg.h
+++ b/gtk2_ardour/transcode_ffmpeg.h
@@ -24,14 +24,6 @@
 #include "ardour/types.h"
 #include "system_exec.h"
 
-/* TODO: use a namespace here ? */
-struct FFAudioStream {
-	std::string name;
-	std::string stream_id;
-	uint32_t channels;
-};
-typedef std::vector<FFAudioStream> AudioStreams;
-typedef std::map<std::string,std::string> FFSettings;
 
 /** @class TranscodeFfmpeg
  *  @brief wrapper around ffmpeg and ffprobe command-line utils
@@ -46,6 +38,15 @@ class TranscodeFfmpeg : public sigc::trackable
 {
 	public:
 
+	struct FFAudioStream {
+		std::string name;
+		std::string stream_id;
+		uint32_t channels;
+	};
+	typedef std::vector<FFAudioStream> FFAudioStreams;
+	typedef std::map<std::string,std::string> FFSettings;
+
+
 		/** instantiate a new transcoder. If a file-name is given, the file's
 		 * attributes (fps, duration, geometry etc) are read.
 		 *
@@ -110,7 +111,7 @@ class TranscodeFfmpeg : public sigc::trackable
 		ARDOUR::framecnt_t get_duration() { return m_duration; }
 		std::string  get_codec() { return m_codec; }
 
-		AudioStreams get_audio() { return m_audio; }
+		FFAudioStreams get_audio() { return m_audio; }
 
 		/** override file duration used with the \ref Progress signal.
 		 * @param d duration in video-frames = length_in_seconds * get_fps()
@@ -145,7 +146,7 @@ class TranscodeFfmpeg : public sigc::trackable
 		bool ffexecok;
 		bool probeok;
 
-		AudioStreams m_audio;
+		FFAudioStreams m_audio;
 
 		char *format_metadata (std::string, std::string);
 		void ffmpegparse_v (std::string d, size_t s);
diff --git a/gtk2_ardour/transcode_video_dialog.cc b/gtk2_ardour/transcode_video_dialog.cc
index fa5d447a3a..5c6ae0c7b4 100644
--- a/gtk2_ardour/transcode_video_dialog.cc
+++ b/gtk2_ardour/transcode_video_dialog.cc
@@ -88,7 +88,7 @@ TranscodeVideoDialog::TranscodeVideoDialog (Session* s, std::string infile)
 
 	int w = 0, h = 0;
 	m_aspect = 4.0/3.0;
-	AudioStreams as; as.clear();
+	TranscodeFfmpeg::FFAudioStreams as; as.clear();
 
 	path_hbox->pack_start (path_label, false, false, 3);
 	path_hbox->pack_start (path_entry, true, true, 3);
@@ -227,7 +227,7 @@ TranscodeVideoDialog::TranscodeVideoDialog (Session* s, std::string infile)
 	t->attach (audio_combo, 1, 4, 2, 3);
 	audio_combo.append_text("No audio");
 	if (as.size() > 0) {
-		for (AudioStreams::iterator it = as.begin(); it < as.end(); ++it) {
+		for (TranscodeFfmpeg::FFAudioStreams::iterator it = as.begin(); it < as.end(); ++it) {
 			audio_combo.append_text((*it).name);
 		}
 	}