diff --git a/ImGuiToolkit.cpp b/ImGuiToolkit.cpp
index 2349f17..e914d59 100644
--- a/ImGuiToolkit.cpp
+++ b/ImGuiToolkit.cpp
@@ -738,7 +738,7 @@ bool ImGuiToolkit::EditPlotLines(const char* label, float *array, int values_cou
 }
 
 bool ImGuiToolkit::EditPlotHistoLines(const char* label, float *histogram_array, float *lines_array,
-                                      int values_count, float values_min, float values_max, bool *released, const ImVec2 size)
+                                      int values_count, float values_min, float values_max, bool cut, bool *released, const ImVec2 size)
 {
     bool array_changed = false;
 
@@ -764,9 +764,7 @@ bool ImGuiToolkit::EditPlotHistoLines(const char* label, float *histogram_array,
     *released = false;
 
     // read user input and activate widget
-    const bool left_mouse_press = ImGui::IsMouseDown(ImGuiMouseButton_Left);
-    const bool right_mouse_press = ImGui::IsMouseDown(ImGuiMouseButton_Right) | (ImGui::GetIO().KeyAlt & left_mouse_press) ;
-    const bool mouse_press = left_mouse_press | right_mouse_press;
+    const bool mouse_press = ImGui::IsMouseDown(ImGuiMouseButton_Left);
     const bool hovered = ImGui::ItemHoverable(bbox, id);
     bool temp_input_is_active = ImGui::TempInputIsActive(id);
     if (!temp_input_is_active)
@@ -805,7 +803,7 @@ bool ImGuiToolkit::EditPlotHistoLines(const char* label, float *histogram_array,
             if (previous_index == UINT32_MAX)
                 previous_index = index;
 
-            if (right_mouse_press){
+            if (cut){
                 static float target_value = values_min;
 
                 // toggle value histo
diff --git a/ImGuiToolkit.h b/ImGuiToolkit.h
index 43598e4..ef76225 100644
--- a/ImGuiToolkit.h
+++ b/ImGuiToolkit.h
@@ -36,7 +36,7 @@ namespace ImGuiToolkit
     bool TimelineSlider (const char* label, guint64 *time, guint64 start, guint64 end, guint64 step, const float width);
     bool InvisibleSliderInt(const char* label, uint *index, uint min, uint max, const ImVec2 size);
     bool EditPlotLines(const char* label, float *array, int values_count, float values_min, float values_max, const ImVec2 size);
-    bool EditPlotHistoLines(const char* label, float *histogram_array, float *lines_array, int values_count, float values_min, float values_max, bool *released, const ImVec2 size);
+    bool EditPlotHistoLines(const char* label, float *histogram_array, float *lines_array, int values_count, float values_min, float values_max, bool cut, bool *released, const ImVec2 size);
 
     // fonts from ressources 'fonts/'
     typedef enum {
diff --git a/MediaSource.cpp b/MediaSource.cpp
index 54fd7c9..c443490 100644
--- a/MediaSource.cpp
+++ b/MediaSource.cpp
@@ -108,12 +108,38 @@ void MediaSource::setActive (bool on)
 {
     bool was_active = active_;
 
+    // try to activate (may fail if source is cloned)
     Source::setActive(on);
 
     // change status of media player (only if status changed)
-    if ( active_ != was_active ) {
+    if ( active_ != was_active )
         mediaplayer_->enable(active_);
-    }
+}
+
+
+bool MediaSource::playing () const
+{
+    return mediaplayer_->isPlaying();
+}
+
+void MediaSource::play (bool on)
+{
+    mediaplayer_->play(on);
+}
+
+bool MediaSource::playable () const
+{
+    return !mediaplayer_->isImage();
+}
+
+void MediaSource::replay ()
+{
+    mediaplayer_->rewind();
+}
+
+guint64 MediaSource::playtime () const
+{
+    return mediaplayer_->position();
 }
 
 void MediaSource::update(float dt)
diff --git a/MediaSource.h b/MediaSource.h
index 122d598..4a31229 100644
--- a/MediaSource.h
+++ b/MediaSource.h
@@ -14,6 +14,11 @@ public:
     // implementation of source API
     void update (float dt) override;
     void setActive (bool on) override;
+    bool playing () const override;
+    void play (bool) override;
+    bool playable () const  override;
+    void replay () override;
+    guint64 playtime () const override;
     void render() override;
     bool failed() const override;
     uint texture() const override;
diff --git a/MultiFileSource.cpp b/MultiFileSource.cpp
index 1e9850a..d1fa92c 100644
--- a/MultiFileSource.cpp
+++ b/MultiFileSource.cpp
@@ -115,6 +115,22 @@ void MultiFile::close ()
     Stream::close();
 }
 
+void MultiFile::setIndex(int val)
+{
+    if (src_) {
+        g_object_set (src_, "index", val, NULL);
+    }
+}
+
+int MultiFile::index()
+{
+    int val = 0;
+    if (src_) {
+        g_object_get (src_, "index", &val, NULL);
+    }
+    return val;
+}
+
 void MultiFile::setProperties (int begin, int end, int loop)
 {
     if (src_) {
@@ -187,6 +203,27 @@ void MultiFileSource::setRange (int begin, int end)
         multifile()->setProperties (begin_, end_, loop_);
 }
 
+void MultiFileSource::replay ()
+{
+    if (multifile()) {
+        multifile()->setIndex (begin_);
+        stream_->rewind();
+    }
+}
+
+guint64 MultiFileSource::playtime () const
+{
+    guint64 time = 0;
+
+    if (multifile())
+        time += multifile()->index();
+
+    time *= GST_SECOND;
+    time /= framerate_;
+
+    return time;
+}
+
 void MultiFileSource::accept (Visitor& v)
 {
     Source::accept(v);
diff --git a/MultiFileSource.h b/MultiFileSource.h
index 5435730..98249c8 100644
--- a/MultiFileSource.h
+++ b/MultiFileSource.h
@@ -31,6 +31,10 @@ public:
     // dynamic change of gstreamer multifile source properties
     void setProperties(int begin, int end, int loop);
 
+    // image index
+    int index();
+    void setIndex(int val);
+
 protected:
     GstElement *src_ ;
 };
@@ -42,6 +46,8 @@ public:
 
     // Source interface
     void accept (Visitor& v) override;
+    void replay () override;
+    guint64 playtime () const override;
 
     // StreamSource interface
     Stream *stream () const override { return stream_; }
diff --git a/Session.cpp b/Session.cpp
index c7a7606..c29b5b8 100644
--- a/Session.cpp
+++ b/Session.cpp
@@ -459,6 +459,59 @@ std::list<MixingGroup *>::iterator Session::endMixingGroup()
     return mixing_groups_.end();
 }
 
+
+size_t Session::numPlayGroups() const
+{
+    return play_groups_.size();
+}
+
+void Session::addPlayGroup(const SourceIdList &ids)
+{
+    play_groups_.push_back( ids );
+}
+
+void Session::addToPlayGroup(size_t i, Source *s)
+{
+    if (i < play_groups_.size() )
+    {
+        if ( std::find(play_groups_[i].begin(), play_groups_[i].end(), s->id()) == play_groups_[i].end() )
+            play_groups_[i].push_back(s->id());
+    }
+}
+
+void Session::removeFromPlayGroup(size_t i, Source *s)
+{
+    if (i < play_groups_.size() )
+    {
+        if ( std::find(play_groups_[i].begin(), play_groups_[i].end(), s->id()) != play_groups_[i].end() )
+            play_groups_[i].remove( s->id() );
+    }
+}
+
+void Session::deletePlayGroup(size_t i)
+{
+    if (i < play_groups_.size() )
+        play_groups_.erase( play_groups_.begin() + i);
+}
+
+SourceList Session::playGroup(size_t i) const
+{
+    SourceList list;
+
+    if (i < play_groups_.size() )
+    {
+        for (auto sid = play_groups_[i].begin(); sid != play_groups_[i].end(); ++sid){
+
+            SourceList::const_iterator it = std::find_if(sources_.begin(), sources_.end(), Source::hasId( *sid));;
+            if ( it != sources_.end())
+                list.push_back( *it);
+
+        }
+    }
+
+    return list;
+}
+
 void Session::lock()
 {
     access_.lock();
diff --git a/Session.h b/Session.h
index a1d710f..c0fc263 100644
--- a/Session.h
+++ b/Session.h
@@ -126,6 +126,15 @@ public:
     // snapshots
     SessionSnapshots * const snapshots () { return &snapshots_; }
 
+    // playlists
+    void addPlayGroup(const SourceIdList &ids);
+    void deletePlayGroup(size_t i);
+    size_t numPlayGroups() const;
+    SourceList playGroup(size_t i) const;
+    void addToPlayGroup(size_t i, Source *s);
+    void removeFromPlayGroup(size_t i, Source *s);
+    std::vector<SourceIdList> getPlayGroups() { return play_groups_; }
+
     // lock and unlock access (e.g. while saving)
     void lock ();
     void unlock ();
@@ -141,6 +150,7 @@ protected:
     std::list<MixingGroup *> mixing_groups_;
     std::map<View::Mode, Group*> config_;
     SessionSnapshots snapshots_;
+    std::vector<SourceIdList> play_groups_;
     float fading_target_;
     std::mutex access_;
 
diff --git a/SessionCreator.cpp b/SessionCreator.cpp
index 513f1ee..daeadb0 100644
--- a/SessionCreator.cpp
+++ b/SessionCreator.cpp
@@ -112,6 +112,9 @@ void SessionCreator::load(const std::string& filename)
     // load notes
     loadNotes( xmlDoc_.FirstChildElement("Notes") );
 
+    // load playlists
+    loadPlayGroups( xmlDoc_.FirstChildElement("PlayGroups") );
+
     // all good
     session_->setFilename(filename);
 }
@@ -163,7 +166,8 @@ void SessionCreator::loadNotes(XMLElement *notesNode)
             XMLElement *sizeNode = note->FirstChildElement("size");
             if (sizeNode)  tinyxml2::XMLElementToGLM( sizeNode->FirstChildElement("vec2"), N.size);
             XMLElement* contentNode = note->FirstChildElement("text");
-            if (contentNode)  N.text = std::string ( contentNode->GetText() );
+            if (contentNode && contentNode->GetText())
+                N.text = std::string ( contentNode->GetText() );
 
             session_->addNote(N);
         }
@@ -171,6 +175,29 @@ void SessionCreator::loadNotes(XMLElement *notesNode)
     }
 }
 
+void SessionCreator::loadPlayGroups(tinyxml2::XMLElement *playgroupNode)
+{
+    if (playgroupNode != nullptr && session_ != nullptr) {
+
+        XMLElement* playgroup = playgroupNode->FirstChildElement("PlayGroup");
+        for( ; playgroup ; playgroup = playgroup->NextSiblingElement())
+        {
+            SourceIdList playgroup_sources;
+
+            XMLElement* playgroupSourceNode = playgroup->FirstChildElement("source");
+            for ( ; playgroupSourceNode ; playgroupSourceNode = playgroupSourceNode->NextSiblingElement()) {
+                uint64_t id__ = 0;
+                playgroupSourceNode->QueryUnsigned64Attribute("id", &id__);
+
+                if (sources_id_.count(id__) > 0)
+                    playgroup_sources.push_back( id__ );
+
+            }
+            session_->addPlayGroup( playgroup_sources );
+        }
+    }
+}
+
 SessionLoader::SessionLoader(): Visitor(),
     session_(nullptr), xmlCurrent_(nullptr), recursion_(0)
 {
diff --git a/SessionCreator.h b/SessionCreator.h
index 321c1ba..a2a769d 100644
--- a/SessionCreator.h
+++ b/SessionCreator.h
@@ -93,6 +93,7 @@ class SessionCreator : public SessionLoader {
 
     void loadConfig(tinyxml2::XMLElement *viewsNode);
     void loadNotes(tinyxml2::XMLElement *notesNode);
+    void loadPlayGroups(tinyxml2::XMLElement *playlistsNode);
     void loadSnapshots(tinyxml2::XMLElement *snapshotNode);
 
 public:
diff --git a/SessionSource.cpp b/SessionSource.cpp
index a33755b..103ceaf 100644
--- a/SessionSource.cpp
+++ b/SessionSource.cpp
@@ -18,7 +18,7 @@
 #include "Mixer.h"
 
 
-SessionSource::SessionSource(uint64_t id) : Source(id), failed_(false)
+SessionSource::SessionSource(uint64_t id) : Source(id), failed_(false), timer_(0), paused_(false)
 {
     session_ = new Session;
 }
@@ -62,11 +62,11 @@ uint SessionSource::texture() const
 }
 
 void SessionSource::setActive (bool on)
-{
+{    
     Source::setActive(on);
 
     // change status of session (recursive change of internal sources)
-    if (session_ != nullptr)
+    if (session_)
         session_->setActive(active_);
 }
 
@@ -76,8 +76,10 @@ void SessionSource::update(float dt)
         return;
 
     // update content
-    if (active_)
+    if (active_ && !paused_) {
         session_->update(dt);
+        timer_ += guint64(dt * 1000.f) * GST_USECOND;
+    }
 
     // delete a source which failed
     if (session_->failedSource() != nullptr) {
@@ -90,6 +92,15 @@ void SessionSource::update(float dt)
     Source::update(dt);
 }
 
+void SessionSource::replay ()
+{
+    if (session_) {
+        for( SourceList::iterator it = session_->begin(); it != session_->end(); ++it)
+            (*it)->replay();
+        timer_ = 0;
+    }
+}
+
 
 SessionFileSource::SessionFileSource(uint64_t id) : SessionSource(id), path_(""), initialized_(false), wait_for_sources_(false)
 {
@@ -150,6 +161,7 @@ void SessionFileSource::load(const std::string &p, uint recursion)
     }
 
     // will be ready after init and one frame rendered
+    initialized_ = false;
     ready_ = false;
 }
 
@@ -332,7 +344,7 @@ RenderSource::RenderSource(uint64_t id) : Source(id), session_(nullptr)
 
 bool RenderSource::failed() const
 {
-    if ( mode_ > Source::UNINITIALIZED && session_!=nullptr )
+    if ( renderbuffer_ != nullptr && session_ != nullptr )
         return renderbuffer_->resolution() != session_->frame()->resolution();
 
     return false;
@@ -372,7 +384,7 @@ void RenderSource::init()
 
 glm::vec3 RenderSource::resolution() const
 {
-    if (mode_ > Source::UNINITIALIZED)
+    if (renderbuffer_ != nullptr)
         return renderbuffer_->resolution();
     else if (session_ && session_->frame())
         return session_->frame()->resolution();
diff --git a/SessionSource.h b/SessionSource.h
index dc7e65f..c37728d 100644
--- a/SessionSource.h
+++ b/SessionSource.h
@@ -14,6 +14,11 @@ public:
     // implementation of source API
     void update (float dt) override;
     void setActive (bool on) override;
+    bool playing () const override { return !paused_; }
+    void play (bool on) override { paused_ = !on; }
+    bool playable () const  override { return true; }
+    guint64 playtime () const override { return timer_; }
+    void replay () override;
     bool failed () const override;
     uint texture () const override;
 
@@ -24,6 +29,8 @@ protected:
 
     Session *session_;
     std::atomic<bool> failed_;
+    guint64 timer_;
+    bool paused_;
 };
 
 class SessionFileSource : public SessionSource
@@ -80,6 +87,9 @@ public:
     RenderSource(uint64_t id = 0);
 
     // implementation of source API
+    bool playing () const override { return true; }
+    void play (bool) override {}
+    bool playable () const  override { return false; }
     bool failed () const override;
     uint texture() const override;
     void accept (Visitor& v) override;
diff --git a/SessionVisitor.cpp b/SessionVisitor.cpp
index f593c5b..f343434 100644
--- a/SessionVisitor.cpp
+++ b/SessionVisitor.cpp
@@ -58,63 +58,109 @@ bool SessionVisitor::saveSession(const std::string& filename, Session *session)
     delete thumbnail;
 
     // 2. config of views
-    XMLElement *views = xmlDoc.NewElement("Views");
-    xmlDoc.InsertEndChild(views);
-    {
-        XMLElement *mixing = xmlDoc.NewElement( "Mixing" );
-        mixing->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::MIXING), &xmlDoc));
-        views->InsertEndChild(mixing);
-
-        XMLElement *geometry = xmlDoc.NewElement( "Geometry" );
-        geometry->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::GEOMETRY), &xmlDoc));
-        views->InsertEndChild(geometry);
-
-        XMLElement *layer = xmlDoc.NewElement( "Layer" );
-        layer->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::LAYER), &xmlDoc));
-        views->InsertEndChild(layer);
-
-        XMLElement *appearance = xmlDoc.NewElement( "Texture" );
-        appearance->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::TEXTURE), &xmlDoc));
-        views->InsertEndChild(appearance);
-
-        XMLElement *render = xmlDoc.NewElement( "Rendering" );
-        render->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::RENDERING), &xmlDoc));
-        views->InsertEndChild(render);
-    }
+    saveConfig( &xmlDoc, session );
 
     // 3. snapshots
-    XMLElement *snapshots = xmlDoc.NewElement("Snapshots");
-    const XMLElement* N = session->snapshots()->xmlDoc_->FirstChildElement();
-    for( ; N ; N=N->NextSiblingElement())
-        snapshots->InsertEndChild( N->DeepClone( &xmlDoc ));
-    xmlDoc.InsertEndChild(snapshots);
+    saveSnapshots( &xmlDoc, session );
 
     // 4. optional notes
-    XMLElement *notes = xmlDoc.NewElement("Notes");
-    xmlDoc.InsertEndChild(notes);
-    for (auto nit = session->beginNotes(); nit != session->endNotes(); ++nit) {
-        XMLElement *note = xmlDoc.NewElement( "Note" );
-        note->SetAttribute("large", (*nit).large );
-        note->SetAttribute("stick", (*nit).stick );
-        XMLElement *pos = xmlDoc.NewElement("pos");
-        pos->InsertEndChild( XMLElementFromGLM(&xmlDoc, (*nit).pos) );
-        note->InsertEndChild(pos);
-        XMLElement *size = xmlDoc.NewElement("size");
-        size->InsertEndChild( XMLElementFromGLM(&xmlDoc, (*nit).size) );
-        note->InsertEndChild(size);
-        XMLElement *content = xmlDoc.NewElement("text");
-        XMLText *text = xmlDoc.NewText( (*nit).text.c_str() );
-        content->InsertEndChild( text );
-        note->InsertEndChild(content);
-
-        notes->InsertEndChild(note);
-    }
+    saveNotes( &xmlDoc, session );
 
+    // 5. optional playlists
+    savePlayGroups( &xmlDoc, session );
 
     // save file to disk
     return ( XMLSaveDoc(&xmlDoc, filename) );
 }
 
+void SessionVisitor::saveConfig(tinyxml2::XMLDocument *doc, Session *session)
+{
+    if (doc != nullptr && session != nullptr)
+    {
+        XMLElement *views = doc->NewElement("Views");
+
+        XMLElement *mixing = doc->NewElement( "Mixing" );
+        mixing->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::MIXING), doc));
+        views->InsertEndChild(mixing);
+
+        XMLElement *geometry = doc->NewElement( "Geometry" );
+        geometry->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::GEOMETRY), doc));
+        views->InsertEndChild(geometry);
+
+        XMLElement *layer = doc->NewElement( "Layer" );
+        layer->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::LAYER), doc));
+        views->InsertEndChild(layer);
+
+        XMLElement *appearance = doc->NewElement( "Texture" );
+        appearance->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::TEXTURE), doc));
+        views->InsertEndChild(appearance);
+
+        XMLElement *render = doc->NewElement( "Rendering" );
+        render->InsertEndChild( SessionVisitor::NodeToXML(*session->config(View::RENDERING), doc));
+        views->InsertEndChild(render);
+
+        doc->InsertEndChild(views);
+    }
+}
+
+
+void SessionVisitor::saveSnapshots(tinyxml2::XMLDocument *doc, Session *session)
+{
+    if (doc != nullptr && session != nullptr)
+    {
+        XMLElement *snapshots = doc->NewElement("Snapshots");
+        const XMLElement* N = session->snapshots()->xmlDoc_->FirstChildElement();
+        for( ; N ; N=N->NextSiblingElement())
+            snapshots->InsertEndChild( N->DeepClone( doc ));
+        doc->InsertEndChild(snapshots);
+    }
+}
+
+void SessionVisitor::saveNotes(tinyxml2::XMLDocument *doc, Session *session)
+{
+    if (doc != nullptr && session != nullptr)
+    {
+        XMLElement *notes = doc->NewElement("Notes");
+        for (auto nit = session->beginNotes(); nit != session->endNotes(); ++nit) {
+            XMLElement *note = doc->NewElement( "Note" );
+            note->SetAttribute("large", (*nit).large );
+            note->SetAttribute("stick", (*nit).stick );
+            XMLElement *pos = doc->NewElement("pos");
+            pos->InsertEndChild( XMLElementFromGLM(doc, (*nit).pos) );
+            note->InsertEndChild(pos);
+            XMLElement *size = doc->NewElement("size");
+            size->InsertEndChild( XMLElementFromGLM(doc, (*nit).size) );
+            note->InsertEndChild(size);
+            XMLElement *content = doc->NewElement("text");
+            XMLText *text = doc->NewText( (*nit).text.c_str() );
+            content->InsertEndChild( text );
+            note->InsertEndChild(content);
+
+            notes->InsertEndChild(note);
+        }
+        doc->InsertEndChild(notes);
+    }
+}
+
+void SessionVisitor::savePlayGroups(tinyxml2::XMLDocument *doc, Session *session)
+{
+    if (doc != nullptr && session != nullptr)
+    {
+        XMLElement *playlistNode = doc->NewElement("PlayGroups");
+        std::vector<SourceIdList> pl = session->getPlayGroups();
+        for (auto plit = pl.begin(); plit != pl.end(); ++plit) {
+            XMLElement *list = doc->NewElement("PlayGroup");
+            playlistNode->InsertEndChild(list);
+            for (auto id = plit->begin(); id != plit->end(); ++id) {
+                XMLElement *sour = doc->NewElement("source");
+                sour->SetAttribute("id", *id);
+                list->InsertEndChild(sour);
+            }
+        }
+        doc->InsertEndChild(playlistNode);
+    }
+}
+
 SessionVisitor::SessionVisitor(tinyxml2::XMLDocument *doc,
                                tinyxml2::XMLElement *root,
                                bool recursive) : Visitor(), recursive_(recursive), xmlCurrent_(root)
diff --git a/SessionVisitor.h b/SessionVisitor.h
index 35961e0..935e75b 100644
--- a/SessionVisitor.h
+++ b/SessionVisitor.h
@@ -14,6 +14,11 @@ class SessionVisitor : public Visitor {
     tinyxml2::XMLDocument *xmlDoc_;
     tinyxml2::XMLElement *xmlCurrent_;
 
+    static void saveConfig(tinyxml2::XMLDocument *doc, Session *session);
+    static void saveSnapshots(tinyxml2::XMLDocument *doc, Session *session);
+    static void saveNotes(tinyxml2::XMLDocument *doc, Session *session);
+    static void savePlayGroups(tinyxml2::XMLDocument *doc, Session *session);
+
 public:
     SessionVisitor(tinyxml2::XMLDocument *doc = nullptr,
                    tinyxml2::XMLElement *root = nullptr,
diff --git a/Settings.cpp b/Settings.cpp
index 68b5101..8c8a456 100644
--- a/Settings.cpp
+++ b/Settings.cpp
@@ -76,6 +76,7 @@ void Settings::Save()
     widgetsNode->SetAttribute("preview", application.widget.preview);
     widgetsNode->SetAttribute("history", application.widget.history);
     widgetsNode->SetAttribute("media_player", application.widget.media_player);
+    widgetsNode->SetAttribute("timeline_editmode", application.widget.timeline_editmode);
     widgetsNode->SetAttribute("shader_editor", application.widget.shader_editor);
     widgetsNode->SetAttribute("stats", application.widget.stats);
     widgetsNode->SetAttribute("stats_mode", application.widget.stats_mode);
@@ -270,6 +271,7 @@ void Settings::Load()
         widgetsNode->QueryBoolAttribute("preview", &application.widget.preview);
         widgetsNode->QueryBoolAttribute("history", &application.widget.history);
         widgetsNode->QueryBoolAttribute("media_player", &application.widget.media_player);
+        widgetsNode->QueryBoolAttribute("timeline_editmode", &application.widget.timeline_editmode);
         widgetsNode->QueryBoolAttribute("shader_editor", &application.widget.shader_editor);
         widgetsNode->QueryBoolAttribute("stats", &application.widget.stats);
         widgetsNode->QueryIntAttribute("stats_mode", &application.widget.stats_mode);
diff --git a/Settings.h b/Settings.h
index bc3f026..94bf8bb 100644
--- a/Settings.h
+++ b/Settings.h
@@ -21,6 +21,7 @@ struct WidgetsConfig
     bool history;
     bool media_player;
     bool media_player_view;
+    bool timeline_editmode;
     bool shader_editor;
     bool toolbox;
 
@@ -33,6 +34,7 @@ struct WidgetsConfig
         history = false;
         media_player = false;
         media_player_view = true;
+        timeline_editmode = false;
         shader_editor = false;
         toolbox = false;
     }
diff --git a/Source.cpp b/Source.cpp
index de56205..1212f59 100644
--- a/Source.cpp
+++ b/Source.cpp
@@ -871,7 +871,6 @@ void CloneSource::setActive (bool on)
         origin_->touch();
 }
 
-
 uint CloneSource::texture() const
 {
     if (origin_ != nullptr)
diff --git a/Source.h b/Source.h
index 44e9b62..99f1c4c 100644
--- a/Source.h
+++ b/Source.h
@@ -139,6 +139,13 @@ public:
     } Workspace;
     inline Workspace workspace () const { return workspace_; }
 
+    // a Source shall define a way to play
+    virtual bool playable () const  = 0;
+    virtual bool playing () const = 0;
+    virtual void play (bool on) = 0;
+    virtual void replay () {}
+    virtual guint64 playtime () const { return 0; }
+
     // a Source shall informs if the source failed (i.e. shall be deleted)
     virtual bool failed () const = 0;
 
@@ -299,6 +306,10 @@ public:
 
     // implementation of source API
     void setActive (bool on) override;
+    bool playing () const override { return true; }
+    void play (bool) override {}
+    bool playable () const  override { return false; }
+    void replay () override {}
     uint texture() const override;
     bool failed() const override  { return origin_ == nullptr; }
     void accept (Visitor& v) override;
diff --git a/SourceList.cpp b/SourceList.cpp
index 14130ee..618fe3d 100644
--- a/SourceList.cpp
+++ b/SourceList.cpp
@@ -14,6 +14,18 @@ bool compare_depth (Source * first, Source * second)
   return ( first->depth() < second->depth() );
 }
 
+
+bool notplayable (const Source *s) { return !s->playable(); }
+
+SourceList playable_only (const SourceList &list)
+{
+    SourceList pl = list;
+
+    pl.remove_if(notplayable);
+
+    return pl;
+}
+
 SourceList depth_sorted(const SourceList &list)
 {
     SourceList sl = list;
diff --git a/SourceList.h b/SourceList.h
index 160b547..549246b 100644
--- a/SourceList.h
+++ b/SourceList.h
@@ -11,6 +11,7 @@ class Session;
 typedef std::list<Source *> SourceList;
 typedef std::list<SourceCore *> SourceCoreList;
 
+SourceList playable_only (const SourceList &list);
 SourceList depth_sorted  (const SourceList &list);
 SourceList mixing_sorted (const SourceList &list, glm::vec2 center = glm::vec2(0.f, 0.f));
 SourceList intersect     (const SourceList &first, const SourceList &second);
diff --git a/Stream.cpp b/Stream.cpp
index 0be660e..cc1f509 100644
--- a/Stream.cpp
+++ b/Stream.cpp
@@ -31,6 +31,7 @@ Stream::Stream()
     opened_ = false;
     enabled_ = true;
     desired_state_ = GST_STATE_PAUSED;
+    position_ = GST_CLOCK_TIME_NONE;
 
     width_ = -1;
     height_ = -1;
@@ -371,7 +372,26 @@ bool Stream::isPlaying(bool testpipeline) const
     return state == GST_STATE_PLAYING;
 }
 
+void Stream::rewind()
+{
+    if ( pipeline_ == nullptr )
+        return;
 
+    GstEvent *seek_event = gst_event_new_seek (1.0, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH,
+                                               GST_SEEK_TYPE_SET, 0, GST_SEEK_TYPE_END, 0);
+    gst_element_send_event(pipeline_, seek_event);
+}
+
+GstClockTime Stream::position()
+{
+    if (position_ == GST_CLOCK_TIME_NONE && pipeline_ != nullptr) {
+        gint64 p = GST_CLOCK_TIME_NONE;
+        if ( gst_element_query_position (pipeline_, GST_FORMAT_TIME, &p) )
+            position_ = p;
+    }
+
+    return position_;
+}
 
 void Stream::init_texture(guint index)
 {
@@ -545,6 +565,9 @@ void Stream::update()
             frame_[read_index].unmap();
         }
 
+        // we just displayed a vframe : set position time to frame PTS
+        position_ = frame_[read_index].position;
+
         // avoid reading it again
         frame_[read_index].status = INVALID;
     }
diff --git a/Stream.h b/Stream.h
index f4c6a4b..4526e55 100644
--- a/Stream.h
+++ b/Stream.h
@@ -83,6 +83,14 @@ public:
      * Performs a full check of the Gstreamer pipeline if testpipeline is true
      * */
     bool isPlaying(bool testpipeline = false) const;
+    /**
+     * Attempt to restart
+     * */
+    virtual void rewind();
+    /**
+     * Get position time
+     * */
+    virtual GstClockTime position();
     /**
      * Get rendering update framerate
      * measured during play
@@ -126,6 +134,7 @@ protected:
     bool live_;
 
     // GST & Play status
+    GstClockTime position_;
     GstState desired_state_;
     GstElement *pipeline_;
     GstVideoInfo v_frame_video_info_;
diff --git a/StreamSource.cpp b/StreamSource.cpp
index 0a50533..470cc76 100644
--- a/StreamSource.cpp
+++ b/StreamSource.cpp
@@ -102,13 +102,49 @@ void StreamSource::setActive (bool on)
 {
     bool was_active = active_;
 
+    // try to activate (may fail if source is cloned)
     Source::setActive(on);
 
-    // change status of media player (only if status changed)
-    if ( active_ != was_active ) {
-        if (stream_)
-            stream_->enable(active_);
-    }
+    // change status of stream (only if status changed)
+    if ( stream_ && active_ != was_active )
+        stream_->enable(active_);
+
+}
+
+
+bool StreamSource::playing () const
+{
+    if ( stream_ )
+        return stream_->isPlaying();
+    return false;
+}
+
+void StreamSource::play (bool on)
+{
+    if ( stream_ )
+        stream_->play(on);
+}
+
+
+bool StreamSource::playable () const
+{
+    if ( stream_ )
+        return !stream_->singleFrame();
+    return false;
+}
+
+void StreamSource::replay ()
+{
+    if ( stream_ )
+        stream_->rewind();
+}
+
+guint64 StreamSource::playtime () const
+{
+    if ( stream_ )
+        return stream_->position();
+    else
+        return 0;
 }
 
 void StreamSource::update(float dt)
diff --git a/StreamSource.h b/StreamSource.h
index 41b944d..cbc6df8 100644
--- a/StreamSource.h
+++ b/StreamSource.h
@@ -30,6 +30,11 @@ public:
     // implementation of source API
     void update (float dt) override;
     void setActive (bool on) override;
+    bool playing () const override;
+    void play (bool) override;
+    bool playable () const  override;
+    void replay () override;
+    guint64 playtime () const override;
     bool failed() const override;
     uint texture() const override;
 
diff --git a/UserInterfaceManager.cpp b/UserInterfaceManager.cpp
index 2053a2e..3363572 100644
--- a/UserInterfaceManager.cpp
+++ b/UserInterfaceManager.cpp
@@ -69,7 +69,7 @@ static TextEditor editor;
 
 #include "UserInterfaceManager.h"
 #define PLOT_ARRAY_SIZE 180
-#define LABEL_AUTO_MEDIA_PLAYER "Active source"
+#define LABEL_AUTO_MEDIA_PLAYER "Selected sources"
 
 // utility functions
 void ShowAboutGStreamer(bool* p_open);
@@ -141,7 +141,6 @@ bool UserInterface::Init()
     ImGuiToolkit::SetFont(ImGuiToolkit::FONT_BOLD, "Roboto-Bold", int(base_font_size) );
     ImGuiToolkit::SetFont(ImGuiToolkit::FONT_ITALIC, "Roboto-Italic", int(base_font_size) );
     ImGuiToolkit::SetFont(ImGuiToolkit::FONT_MONO, "Hack-Regular", int(base_font_size) - 2);
-    // font for Navigator = 1.5 x base size (with low oversampling)
     ImGuiToolkit::SetFont(ImGuiToolkit::FONT_LARGE, "Hack-Regular", MIN(int(base_font_size * 1.5f), 50), 1 );
 
     // info
@@ -216,10 +215,10 @@ void UserInterface::handleKeyboard()
             // New Session
             Mixer::manager().close();
         }
-//        else if (ImGui::IsKeyPressed( GLFW_KEY_SPACE )) {
-//            // New Session
-//            Mixer::manager().session()->setActive( !Mixer::manager().session()->active() );
-//        }
+        else if (ImGui::IsKeyPressed( GLFW_KEY_SPACE )) {
+            // New Session
+            Mixer::manager().session()->setActive( !Mixer::manager().session()->active() );
+        }
         else if (ImGui::IsKeyPressed( GLFW_KEY_L )) {
             // Logs
             Settings::application.widget.logs = !Settings::application.widget.logs;
@@ -752,7 +751,8 @@ void UserInterface::Render()
         if (Settings::application.widget.history)
             RenderHistory();
         if (Settings::application.widget.media_player)
-            mediacontrol.Render();
+            sourcecontrol.Render();
+//        mediacontrol.Render();
         if (Settings::application.widget.shader_editor)
             RenderShaderEditor();
         if (Settings::application.widget.logs)
@@ -2293,7 +2293,7 @@ void MediaController::Render()
                 if ( ImGuiToolkit::EditPlotHistoLines("##TimelineArray",
                                                       mp_->timeline()->gapsArray(),
                                                       mp_->timeline()->fadingArray(),
-                                                      MAX_TIMELINE_ARRAY, 0.f, 1.f, &released, size) ) {
+                                                      MAX_TIMELINE_ARRAY, 0.f, 1.f, true, &released, size) ) {
                     mp_->timeline()->update();
                 }
                 else if (released) {
@@ -2343,6 +2343,668 @@ void MediaController::Render()
     ImGui::End();
 }
 
+
+///
+/// SOURCE CONTROLLER
+///
+SourceController::SourceController() : active_label_(LABEL_AUTO_MEDIA_PLAYER),
+    active_selection_(-1), media_playing_mode_(false), slider_pressed_(false)
+{
+}
+
+
+
+void SourceController::Render()
+{
+//    ImGui::SetNextWindowPos(ImVec2(1180, 400), ImGuiCond_FirstUseEver);
+//    ImGui::SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
+
+    // estimate window size
+    const ImGuiContext& g = *GImGui;
+    _h_space = g.Style.WindowPadding.x;
+    _v_space = g.Style.FramePadding.y;
+    _buttons_height  = g.FontSize + _v_space * 4.0f ;
+    _min_width = 6.f * _buttons_height;
+    _timeline_height = (g.FontSize + _v_space) * 2.0f ; // double line for each timeline
+    _scrollbar = g.Style.ScrollbarSize;
+    // all together: 1 title bar + spacing + 1 toolbar + spacing + 2 timelines + scrollbar
+    _mediaplayer_height = _buttons_height + 2.f * _timeline_height + _scrollbar + 2.f * _v_space;
+
+    // constraint position
+    static ImVec2 source_window_pos = ImVec2(1180, 20);
+    static ImVec2 source_window_size = ImVec2(400, 260);
+    SetNextWindowVisible(source_window_pos, source_window_size);
+
+    ImGui::SetNextWindowSizeConstraints(ImVec2(_min_width, 2.f * _mediaplayer_height), ImVec2(FLT_MAX, FLT_MAX));
+
+    if ( !ImGui::Begin(IMGUI_TITLE_MEDIAPLAYER, &Settings::application.widget.media_player, ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_MenuBar | ImGuiWindowFlags_NoTitleBar |  ImGuiWindowFlags_NoCollapse ))
+    {
+        ImGui::End();
+        return;
+    }
+    source_window_pos = ImGui::GetWindowPos();
+    source_window_size = ImGui::GetWindowSize();
+
+
+    // menu (no title bar)
+    if (ImGui::BeginMenuBar())
+    {
+        if (ImGuiToolkit::IconButton(4,16))
+            Settings::application.widget.media_player = false;
+        if (ImGui::BeginMenu(IMGUI_TITLE_MEDIAPLAYER))
+        {
+
+            if ( ImGui::MenuItem( ICON_FA_TIMES "  Close", CTRL_MOD "P") )
+                Settings::application.widget.media_player = false;
+
+            ImGui::EndMenu();
+        }
+
+        if (ImGui::BeginMenu(active_label_.c_str()))
+        {
+            if (ImGui::MenuItem("Selected sources")) {
+                active_selection_ = -1;
+                active_label_ = LABEL_AUTO_MEDIA_PLAYER;
+            }
+
+            // display list of available media
+            for (size_t i = 0 ; i < Mixer::manager().session()->numPlayGroups(); ++i)
+            {
+                std::string label = std::string("Selection #") + std::to_string(i);
+                if (ImGui::MenuItem( label.c_str() )) {
+                    active_selection_ = i;
+                    active_label_ = label;
+                }
+            }
+
+            if (ImGui::MenuItem("New selection"))
+            {
+                active_selection_ = Mixer::manager().session()->numPlayGroups();
+                active_label_ = std::string("Selection #") + std::to_string(active_selection_);
+                Mixer::manager().session()->addPlayGroup( ids(playable_only(Mixer::selection().getCopy())) );
+            }
+
+
+            ImGui::EndMenu();
+        }
+
+        ImGui::EndMenuBar();
+    }
+
+
+    if (active_selection_ > -1) {
+        selection_ = Mixer::manager().session()->playGroup(active_selection_);
+        RenderSelection(active_selection_);
+    }
+    else {
+        selection_ = playable_only(Mixer::selection().getCopy());
+        RenderSelectedSources();
+    }
+
+    ImGui::End();
+
+}
+
+void SourceController::RenderSelection(size_t i)
+{
+    ImVec2 top = ImGui::GetCursorScreenPos();
+    ImVec2 rendersize = ImGui::GetContentRegionAvail() - ImVec2(0, _buttons_height + _scrollbar + _v_space);
+    ImVec2 bottom = ImVec2(top.x, top.y + rendersize.y + _v_space);
+
+    int numsources = selection_.size();
+    // no source selected
+    if (numsources < 1)
+    {
+
+    }
+    else {
+        ///
+        /// Sources grid
+        ///
+        ImGui::BeginChild("##v_scroll", rendersize, false, ImGuiWindowFlags_AlwaysVerticalScrollbar);
+        {
+            // area horizontal pack
+            int numcolumns = CLAMP( int(ceil(1.0f * rendersize.x / rendersize.y)), 1, numsources );
+            ImGui::Columns( numcolumns, "##selectiongrid", false);
+
+            for (auto source = selection_.begin(); source != selection_.end(); ++source) {
+
+                FrameBuffer *frame = (*source)->frame();
+                ImVec2 framesize(ImGui::GetColumnWidth(), ImGui::GetColumnWidth() / frame->aspectRatio());
+
+                ImVec2 image_top = ImGui::GetCursorPos();
+                ImGui::SetCursorPosX(image_top.x -_h_space );
+                ImGui::Image((void*)(uintptr_t) (*source)->texture(), framesize);
+                ImVec2 image_bottom = ImGui::GetCursorPos();
+
+                // Play icon lower left corner
+                ImGuiToolkit::PushFont(ImGuiToolkit::FONT_MONO);
+                ImGui::SetCursorPos(image_top + ImVec2( numcolumns > 1 ? 0.f : _h_space, framesize.y - ImGui::GetTextLineHeightWithSpacing()));
+                if ((*source)->active())
+                    ImGui::Text("%s %s", (*source)->playing() ? ICON_FA_PLAY : ICON_FA_PAUSE, GstToolkit::time_to_string((*source)->playtime()).c_str() );
+                else
+                    ImGui::Text("%s %s", ICON_FA_SNOWFLAKE, GstToolkit::time_to_string((*source)->playtime()).c_str() );
+                ImGui::PopFont();
+
+                ImGui::SetCursorPos(image_bottom);
+                ImGui::NextColumn();
+            }
+
+            ImGui::Columns(1);
+        }
+        ImGui::EndChild();
+    }
+
+    ///
+    /// Play button bar
+    ///
+    DrawButtonBar(bottom, rendersize.x);
+
+    ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0.00f, 0.00f, 0.00f, 0.00f));
+    ImGui::PushStyleColor(ImGuiCol_FrameBg, ImVec4(0.00f, 0.00f, 0.00f, 0.00f));
+    ImGui::PushStyleColor(ImGuiCol_FrameBgHovered, ImVec4(0.14f, 0.14f, 0.14f, 0.7f));
+    ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0.14f, 0.14f, 0.14f, 0.7f));
+
+    ImGui::SetCursorScreenPos(bottom + ImVec2(rendersize.x * 0.6f, _v_space) );
+    ImGui::SetNextItemWidth(-_h_space);
+    std::string label = std::to_string(numsources) + ( numsources > 1 ? " sources" : " source");
+    if (ImGui::BeginCombo("##SelectionImport", label.c_str()))
+    {
+        for (auto s = Mixer::manager().session()->begin(); s != Mixer::manager().session()->end(); ++s) {
+            if ( (*s)->playable() ) {
+
+                if (std::find(selection_.begin(),selection_.end(),*s) == selection_.end()) {
+                    if (ImGui::MenuItem( (*s)->name().c_str() ))
+                        Mixer::manager().session()->addToPlayGroup(i, *s);
+                }
+                else {
+                    if (ImGui::MenuItem( (*s)->name().c_str(), ICON_FA_CHECK ))
+                        Mixer::manager().session()->removeFromPlayGroup(i, *s);
+                }
+            }
+        }
+        ImGui::EndCombo();
+    }
+
+    ImGui::PopStyleColor(4);
+
+
+//    const float preview_height = 4.5f * ImGui::GetFrameHeightWithSpacing();
+
+//    ImGui::Columns(2, NULL, true);
+
+//    //    selection_ = Mixer::manager().session()->getDepthSortedList();
+
+//    Source *_toremove = nullptr;
+//    for (auto source = selection_.begin(); source != selection_.end(); ++source) {
+
+//        FrameBuffer *frame = (*source)->frame();
+//        float width = ImGui::GetColumnWidth();
+//        float height = width / frame->aspectRatio();
+//        if (height > preview_height) {
+//            height = preview_height;
+//            width = height * frame->aspectRatio();
+//        }
+//        ImVec2 top = ImGui::GetCursorPos();
+//        ImGui::Image((void*)(uintptr_t) (*source)->texture(), ImVec2(width, height));
+//        ImVec2 bottom = ImGui::GetCursorPos();
+
+//        // Context menu button up-left corner
+//        if (ImGui::IsItemHovered(ImGuiHoveredFlags_RectOnly))
+//        {
+//            ImGui::SetCursorPos(top + ImVec2(_h_space, _v_space));
+//            if (ImGuiToolkit::ButtonIcon(5, 8))
+//                ImGui::OpenPopup( "MenuSourceControl" );
+//            if (ImGui::BeginPopup( "MenuSourceControl" ))
+//            {
+//                if (ImGui::MenuItem(ICON_FA_MINUS_SQUARE " Remove from selection" )){
+//                    _toremove = *source;
+//                }
+//                if (ImGui::MenuItem(ICON_FA_FILM " Open in Player" )){
+
+//                }
+//                ImGui::EndPopup();
+//            }
+//        }
+
+//        // Play icon lower left corner
+//        ImGui::SetCursorPos(top + ImVec2(_h_space, height - ImGui::GetTextLineHeightWithSpacing()));
+//        if ((*source)->active())
+//            ImGui::Text("%s", (*source)->playing() ? ICON_FA_PLAY : ICON_FA_PAUSE );
+//        else
+//            ImGui::Text(ICON_FA_SNOWFLAKE);
+
+
+//        ImGui::SetCursorPos(bottom + ImVec2(0, _v_space));
+//        ImGui::NextColumn();
+
+//    }
+//    // apply source removal
+//    if (_toremove)
+//        selection_.remove(_toremove);
+
+//    // Add source in selection
+//    ImGuiToolkit::PushFont(ImGuiToolkit::FONT_LARGE);
+//    if (ImGuiToolkit::IconButton(ICON_FA_PLUS_SQUARE))
+//        ImGui::OpenPopup( "SelectionAddSourceList" );
+//    ImGui::PopFont();
+//    if (ImGui::BeginPopup( "SelectionAddSourceList" ))
+//    {
+//        uint count = 0;
+//        for (auto s = Mixer::manager().session()->begin(); s != Mixer::manager().session()->end(); ++s) {
+//            if ( (*s)->playable() && std::find(selection_.begin(),selection_.end(),*s) == selection_.end()) {
+//                if (ImGui::MenuItem( (*s)->name().c_str() ))
+//                    selection_.push_back( *s );
+//                ++count;
+//            }
+//        }
+//        if (count<1)
+//            ImGui::MenuItem( "No playable source available ", 0, false, false);
+//        ImGui::EndPopup();
+//    }
+
+//    ImGui::Columns(1);
+
+
+}
+
+void SourceController::RenderSelectedSources()
+{
+
+    ImVec2 top = ImGui::GetCursorScreenPos();
+    ImVec2 rendersize = ImGui::GetContentRegionAvail() - ImVec2(0, _buttons_height + _scrollbar + _v_space);
+    ImVec2 bottom = ImVec2(top.x, top.y + rendersize.y + _v_space);
+
+    int numsources = selection_.size();
+    // no source selected
+    if (numsources < 1)
+    {
+        ///
+        /// Centered text
+        ///
+        ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.6, 0.6, 0.6, 0.5f));
+        ImVec2 center = rendersize * ImVec2(0.5f, 0.5f);
+        ImGuiToolkit::PushFont(ImGuiToolkit::FONT_ITALIC);
+        center.x -= ImGui::GetTextLineHeight() * 2.f;
+        ImGui::SetCursorScreenPos(top + center);
+        ImGui::Text("Nothing to play");
+        ImGui::PopFont();
+        ImGui::PopStyleColor(1);
+        ///
+        /// Play button bar
+        ///
+        DrawButtonBar(bottom, rendersize.x);
+
+    }
+    // single source selected
+    else if (numsources < 2)
+    {
+        ///
+        /// Sources display
+        ///
+        RenderSingleSource( selection_.front() );
+    }
+    // Several sources selected
+    else {
+
+        ///
+        /// Sources grid
+        ///
+        ImGui::BeginChild("##v_scroll", rendersize, false, ImGuiWindowFlags_AlwaysVerticalScrollbar);
+        {
+            // area horizontal pack
+            int numcolumns = CLAMP( int(ceil(1.0f * rendersize.x / rendersize.y)), 1, numsources );
+            ImGui::Columns( numcolumns, "##selectiongrid", false);
+
+            for (auto source = selection_.begin(); source != selection_.end(); ++source) {
+
+                FrameBuffer *frame = (*source)->frame();
+                ImVec2 framesize(ImGui::GetColumnWidth(), ImGui::GetColumnWidth() / frame->aspectRatio());
+
+                ImVec2 image_top = ImGui::GetCursorPos();
+                ImGui::SetCursorPosX(image_top.x -_h_space );
+                ImGui::Image((void*)(uintptr_t) (*source)->texture(), framesize);
+                ImVec2 image_bottom = ImGui::GetCursorPos();
+
+                // Play icon lower left corner
+                ImGuiToolkit::PushFont(ImGuiToolkit::FONT_MONO);
+                ImGui::SetCursorPos(image_top + ImVec2( numcolumns > 1 ? 0.f : _h_space, framesize.y - ImGui::GetTextLineHeightWithSpacing()));
+                if ((*source)->active())
+                    ImGui::Text("%s %s", (*source)->playing() ? ICON_FA_PLAY : ICON_FA_PAUSE, GstToolkit::time_to_string((*source)->playtime()).c_str() );
+                else
+                    ImGui::Text("%s %s", ICON_FA_SNOWFLAKE, GstToolkit::time_to_string((*source)->playtime()).c_str() );
+                ImGui::PopFont();
+
+                ImGui::SetCursorPos(image_bottom);
+                ImGui::NextColumn();
+            }
+
+            ImGui::Columns(1);
+        }
+        ImGui::EndChild();
+
+        ///
+        /// Play button bar
+        ///
+        DrawButtonBar(bottom, rendersize.x);
+    }
+
+}
+
+void SourceController::RenderSingleSource(Source *s)
+{
+    if ( s == nullptr)
+        return;
+
+    // in case of a MediaSource
+    MediaSource *ms = dynamic_cast<MediaSource *>(s);
+    if ( ms != nullptr) {
+        RenderMediaPlayer( ms->mediaplayer() );
+    }
+    else
+    {
+        ImVec2 top = ImGui::GetCursorScreenPos();
+        ImVec2 rendersize = ImGui::GetContentRegionAvail() - ImVec2(0, _buttons_height + _scrollbar + _v_space);
+        ImVec2 bottom = ImVec2(top.x, top.y + rendersize.y + _v_space);
+
+        ///
+        /// Centered frame
+        ///
+        FrameBuffer *frame = s->frame();
+        ImVec2 framesize = rendersize;
+        ImVec2 corner(0.f, 0.f);
+        ImVec2 tmp = ImVec2(framesize.y * frame->aspectRatio(), framesize.x / frame->aspectRatio());
+        if (tmp.x > framesize.x) {
+            corner.y = (framesize.y - tmp.y) / 2.f;
+            framesize.y = tmp.y;
+        }
+        else {
+            corner.x = (framesize.x - tmp.x) / 2.f;
+            framesize.x = tmp.x;
+        }
+
+        ImGui::SetCursorScreenPos(top + corner);
+        ImGui::Image((void*)(uintptr_t) s->texture(), framesize);
+
+        // Play icon lower left corner
+        ImGuiToolkit::PushFont(framesize.x > 200.f ? ImGuiToolkit::FONT_LARGE : ImGuiToolkit::FONT_MONO);
+        ImGui::SetCursorScreenPos(top + corner + ImVec2(_h_space, framesize.y - ImGui::GetTextLineHeightWithSpacing()));
+        if (s->active())
+            ImGui::Text("%s %s", s->playing() ? ICON_FA_PLAY : ICON_FA_PAUSE, GstToolkit::time_to_string(s->playtime()).c_str() );
+        else
+            ImGui::Text("%s %s", ICON_FA_SNOWFLAKE, GstToolkit::time_to_string(s->playtime()).c_str() );
+        ImGui::PopFont();
+
+        ///
+        /// Play source button bar
+        ///
+        DrawButtonBar(bottom, rendersize.x);
+
+    }
+}
+
+void SourceController::RenderMediaPlayer(MediaPlayer *mp)
+{
+    static float timeline_zoom = 1.f;
+    const float slider_zoom_width = _timeline_height / 2.f;
+
+    ImVec2 top = ImGui::GetCursorScreenPos();
+    ImVec2 rendersize = ImGui::GetContentRegionAvail() - ImVec2(0, _mediaplayer_height);
+    ImVec2 bottom = ImVec2(top.x, top.y + rendersize.y + _v_space);
+
+    ///
+    /// Centered frame
+    ///
+    ImVec2 framesize = rendersize;
+    ImVec2 corner(0.f, 0.f);
+    ImVec2 tmp = ImVec2(framesize.y * mp->aspectRatio(), framesize.x / mp->aspectRatio());
+    if (tmp.x > framesize.x) {
+        corner.y = (framesize.y - tmp.y) / 2.f;
+        framesize.y = tmp.y;
+    }
+    else {
+        corner.x = (framesize.x - tmp.x) / 2.f;
+        framesize.x = tmp.x;
+    }
+
+    ImGui::SetCursorScreenPos(top + corner);
+    ImGui::Image((void*)(uintptr_t) mp->texture(), framesize);
+
+    // Play icon lower left corner
+    ImGuiToolkit::PushFont(framesize.x > 200.f ? ImGuiToolkit::FONT_LARGE : ImGuiToolkit::FONT_MONO);
+    ImGui::SetCursorScreenPos(top + corner + ImVec2(_h_space, framesize.y - ImGui::GetTextLineHeightWithSpacing()));
+    if (mp->isEnabled())
+        ImGui::Text("%s %s", mp->isPlaying() ? ICON_FA_PLAY : ICON_FA_PAUSE, GstToolkit::time_to_string(mp->position()).c_str() );
+    else
+        ImGui::Text("%s %s", ICON_FA_SNOWFLAKE, GstToolkit::time_to_string(mp->position()).c_str() );
+    ImGui::PopFont();
+
+    ///
+    /// media player buttons bar
+    ///
+    ImDrawList* draw_list = ImGui::GetWindowDrawList();
+    draw_list->AddRectFilled(bottom, bottom + ImVec2(rendersize.x, _buttons_height), ImGui::GetColorU32(ImGuiCol_FrameBg), _h_space);
+
+    // buttons style
+    ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.f, 1.f, 1.f, 1.0f));
+    ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0.00f, 0.00f, 0.00f, 0.00f));
+    ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0.24f, 0.24f, 0.24f, 0.7f));
+    ImGui::PushStyleColor(ImGuiCol_FrameBg, ImVec4(0.24f, 0.24f, 0.24f, 0.2f));
+    ImGui::PushStyleColor(ImGuiCol_FrameBgHovered, ImVec4(0.14f, 0.14f, 0.14f, 0.4f));
+
+    ImGui::SetCursorScreenPos(bottom + ImVec2(_h_space, _v_space) );
+    if (ImGui::Button(mp->playSpeed() > 0 ? ICON_FA_FAST_BACKWARD :ICON_FA_FAST_FORWARD))
+        mp->rewind();
+
+    // ignore actual play status of mediaplayer when slider is pressed
+    if (!slider_pressed_)
+        media_playing_mode_ = mp->isPlaying();
+
+    // display buttons Play/Stop depending on current playing mode
+    ImGui::SameLine(0, _h_space);
+    if (media_playing_mode_) {
+        if (ImGui::Button(ICON_FA_PAUSE))
+            media_playing_mode_ = false;
+        ImGui::SameLine(0, _h_space);
+
+        ImGui::PushButtonRepeat(true);
+        if (ImGui::Button( mp->playSpeed() < 0 ? ICON_FA_BACKWARD :ICON_FA_FORWARD))
+            mp->jump ();
+        ImGui::PopButtonRepeat();
+    }
+    else {
+        if (ImGui::Button(ICON_FA_PLAY))
+            media_playing_mode_ = true;
+        ImGui::SameLine(0, _h_space);
+
+        ImGui::PushButtonRepeat(true);
+        if (ImGui::Button( mp->playSpeed() < 0 ? ICON_FA_STEP_BACKWARD : ICON_FA_STEP_FORWARD))
+            mp->step();
+        ImGui::PopButtonRepeat();
+    }
+
+    // loop modes button
+    ImGui::SameLine(0, _h_space);
+    static int current_loop = 0;
+    static std::vector< std::pair<int, int> > iconsloop = { {0,15}, {1,15}, {19,14} };
+    current_loop = (int) mp->loop();
+    if ( ImGuiToolkit::ButtonIconMultistate(iconsloop, &current_loop) )
+        mp->setLoop( (MediaPlayer::LoopMode) current_loop );
+
+    // speed slider (if enough space)
+    float speed = static_cast<float>(mp->playSpeed());
+    if ( rendersize.x > _min_width * 1.4f ) {
+        ImGui::SameLine(0, MAX(_h_space * 2.f, rendersize.x - _min_width * 1.6f) );
+        ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x - _buttons_height );
+        if (ImGui::DragFloat( "##Speed", &speed, 0.01f, -10.f, 10.f, "Speed x %.1f", 2.f))
+            mp->setPlaySpeed( static_cast<double>(speed) );
+    }
+
+    ImGui::SameLine();
+    ImGui::SetCursorPosX(rendersize.x - _buttons_height / 1.5f);
+
+    // Timeline popup menu
+    if (ImGuiToolkit::IconButton(5,8) )
+        ImGui::OpenPopup( "MenuTimeline" );
+    if (ImGui::BeginPopup( "MenuTimeline" ))
+    {
+        if (ImGui::MenuItem("Reset Speed" )){
+            speed = 1.f;
+            mp->setPlaySpeed( static_cast<double>(speed) );
+        }
+        if (ImGui::MenuItem( "Reset Timeline" )){
+            timeline_zoom = 1.f;
+            mp->timeline()->clearFading();
+            mp->timeline()->clearGaps();
+            Action::manager().store("Timeline Reset");
+        }
+        if (ImGui::BeginMenu("Smooth curve"))
+        {
+            const char* names[] = { "Just a little", "A bit more", "Quite a lot"};
+            for (int i = 0; i < IM_ARRAYSIZE(names); ++i) {
+                if (ImGui::MenuItem(names[i])) {
+                    mp->timeline()->smoothFading( 10 * (int) pow(4, i) );
+                    Action::manager().store("Timeline Smooth curve");
+                }
+            }
+            ImGui::EndMenu();
+        }
+        if (ImGui::BeginMenu("Auto fading"))
+        {
+            const char* names[] = { "250 ms", "500 ms", "1 second", "2 seconds"};
+            for (int i = 0; i < IM_ARRAYSIZE(names); ++i) {
+                if (ImGui::MenuItem(names[i])) {
+                    mp->timeline()->autoFading( 250 * (int ) pow(2, i) );
+                    mp->timeline()->smoothFading( 10 * (i + 1) );
+                    Action::manager().store("Timeline Auto fading");
+                }
+            }
+            ImGui::EndMenu();
+        }
+        if (Settings::application.render.gpu_decoding && ImGui::BeginMenu("Hardware Decoding"))
+        {
+            bool hwdec = !mp->softwareDecodingForced();
+            if (ImGui::MenuItem("Auto", "", &hwdec ))
+                mp->setSoftwareDecodingForced(false);
+            hwdec = mp->softwareDecodingForced();
+            if (ImGui::MenuItem("Disabled", "", &hwdec ))
+                mp->setSoftwareDecodingForced(true);
+            ImGui::EndMenu();
+        }
+        ImGui::EndPopup();
+    }
+
+    // restore buttons style
+    ImGui::PopStyleColor(5);
+
+    ///
+    /// media player timelines
+    ///
+    ImGui::SetCursorScreenPos(bottom + ImVec2(0, _buttons_height + _v_space) );
+
+    // seek position
+    guint64 seek_t = mp->position();
+
+    // scrolling sub-window
+    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(1.f, 1.f));
+    ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, 1.f);
+
+    ImVec2 top_scrollwindow = ImGui::GetCursorPos();
+    ImVec2 scrollwindow = ImVec2(ImGui::GetContentRegionAvail().x - slider_zoom_width - 3.0,
+                                 2.f * _timeline_height + _scrollbar );
+
+    ImGui::BeginChild("##scrolling", scrollwindow,  false, ImGuiWindowFlags_HorizontalScrollbar);
+    {
+        ImVec2 size = ImGui::CalcItemSize(ImVec2(-FLT_MIN, 0.0f), ImGui::CalcItemWidth(), _timeline_height -1);
+        size.x *= timeline_zoom;
+
+        bool released = false;
+        if ( ImGuiToolkit::EditPlotHistoLines("##TimelineArray",
+                                              mp->timeline()->gapsArray(),
+                                              mp->timeline()->fadingArray(),
+                                              MAX_TIMELINE_ARRAY, 0.f, 1.f,
+                                              Settings::application.widget.timeline_editmode, &released, size) ) {
+            mp->timeline()->update();
+        }
+        else if (released) {
+            Action::manager().store("Timeline change");
+        }
+
+        // custom timeline slider
+        slider_pressed_ = ImGuiToolkit::TimelineSlider("##timeline", &seek_t, mp->timeline()->begin(),
+                                                       mp->timeline()->end(), mp->timeline()->step(), size.x);
+
+    }
+    ImGui::EndChild();
+
+    ImGui::PopStyleVar(2);
+
+    // action mode
+    ImGui::SetCursorPos(top_scrollwindow + ImVec2(scrollwindow.x + 3.f, 0));
+    ImGuiToolkit::IconToggle(7,4,8,3,&Settings::application.widget.timeline_editmode);
+
+    // zoom slider
+    ImGui::SetCursorPos(top_scrollwindow + ImVec2(scrollwindow.x + 3.f, 0.5f * _timeline_height  + 3.f));
+    ImGui::VSliderFloat("##TimelineZoom", ImVec2(slider_zoom_width, 1.5f * _timeline_height - 3.f), &timeline_zoom, 1.0, 5.f, "");
+
+    ///
+    /// media player actions
+    ///
+    ///
+    // request seek (ASYNC)
+    if ( slider_pressed_ && mp->go_to(seek_t) )
+        slider_pressed_ = false;
+
+    // play/stop command should be following the playing mode (buttons)
+    // AND force to stop when the slider is pressed
+    bool media_play = media_playing_mode_ & (!slider_pressed_);
+
+    // apply play action to media only if status should change
+    if ( mp->isPlaying() != media_play ) {
+        mp->play( media_play );
+    }
+}
+
+void SourceController::DrawButtonBar(ImVec2 bottom, float width)
+{
+    ImDrawList* draw_list = ImGui::GetWindowDrawList();
+    draw_list->AddRectFilled(bottom, bottom + ImVec2(width, _buttons_height), ImGui::GetColorU32(ImGuiCol_FrameBg), _h_space);
+
+    // buttons style: inactive if no source in selection
+    if (selection_.empty()) {
+        ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.6, 0.6, 0.6, 0.5f));
+        ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0.00f, 0.00f, 0.00f, 0.00f));
+        ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0.00f, 0.00f, 0.00f, 0.00f));
+    }
+    else {
+        ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.f, 1.f, 1.f, 1.0f));
+        ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0.00f, 0.00f, 0.00f, 0.00f));
+        ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0.24f, 0.24f, 0.24f, 0.7f));
+    }
+
+    ImGui::SetCursorScreenPos(bottom + ImVec2(_h_space, _v_space) );
+    if (ImGui::Button(ICON_FA_FAST_BACKWARD))
+    {
+        for (auto source = selection_.begin(); source != selection_.end(); ++source)
+            (*source)->replay();
+    }
+    ImGui::SameLine(0, _h_space);
+    if (ImGui::Button(ICON_FA_PLAY))
+    {
+        for (auto source = selection_.begin(); source != selection_.end(); ++source)
+            (*source)->play(true);
+    }
+    ImGui::SameLine(0, _h_space);
+    if (ImGui::Button(ICON_FA_PAUSE))
+    {
+        for (auto source = selection_.begin(); source != selection_.end(); ++source)
+            (*source)->play(false);
+    }
+
+    // restore
+    ImGui::PopStyleColor(3);
+}
+
 ///
 /// NAVIGATOR
 ///
diff --git a/UserInterfaceManager.h b/UserInterfaceManager.h
index d5f579c..460f415 100644
--- a/UserInterfaceManager.h
+++ b/UserInterfaceManager.h
@@ -10,8 +10,9 @@
 #define NAV_MENU 66
 #define NAV_TRANS 67
 
+#include "SourceList.h"
+
 struct ImVec2;
-class Source;
 class MediaPlayer;
 class FrameBufferImage;
 class FrameGrabber;
@@ -119,6 +120,36 @@ public:
     void Render();
 };
 
+class SourceController
+{
+    float _min_width;
+    float _h_space;
+    float _v_space;
+    float _buttons_height;
+    float _timeline_height;
+    float _scrollbar;
+    float _mediaplayer_height;
+
+    std::string active_label_;
+    int active_selection_;
+
+    SourceList selection_;
+    void DrawButtonBar(ImVec2 bottom, float width);
+
+    void RenderSelectedSources();
+    void RenderSelection(size_t i);
+    void RenderSingleSource(Source *s);
+
+    bool media_playing_mode_;
+    bool slider_pressed_;
+    void RenderMediaPlayer(MediaPlayer *mp);
+
+public:
+    SourceController();
+
+    void Render();
+};
+
 
 class UserInterface
 {
@@ -126,6 +157,7 @@ class UserInterface
     Navigator navigator;
     ToolBox toolbox;
     MediaController mediacontrol;
+    SourceController sourcecontrol;
 
     bool ctrl_modifier_active;
     bool alt_modifier_active;