diff --git a/CMakeLists.txt b/CMakeLists.txt
index 86ad45d..0563969 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -292,6 +292,7 @@ set(VMIX_SRCS
     TextureView.cpp
     TransitionView.cpp
     Source.cpp
+    CloneSource.cpp
     SourceCallback.cpp
     SourceList.cpp
     Session.cpp
diff --git a/CloneSource.cpp b/CloneSource.cpp
new file mode 100644
index 0000000..963aafa
--- /dev/null
+++ b/CloneSource.cpp
@@ -0,0 +1,129 @@
+/*
+ * This file is part of vimix - video live mixer
+ *
+ * **Copyright** (C) 2019-2022 Bruno Herbelin <bruno.herbelin@gmail.com>
+ *
+ * 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 <https://www.gnu.org/licenses/>.
+**/
+
+#include <glm/gtc/matrix_access.hpp>
+
+#include "Log.h"
+#include "Resource.h"
+#include "Visitor.h"
+#include "Decorations.h"
+
+#include "CloneSource.h"
+
+
+CloneSource *Source::clone(uint64_t id)
+{
+    CloneSource *s = new CloneSource(this, id);
+
+    clones_.push_back(s);
+
+    return s;
+}
+
+
+CloneSource::CloneSource(Source *origin, uint64_t id) : Source(id), origin_(origin)
+{
+    name_ = origin->name();
+    // set symbol
+    symbol_ = new Symbol(Symbol::CLONE, glm::vec3(0.75f, 0.75f, 0.01f));
+    symbol_->scale_.y = 1.5f;
+}
+
+CloneSource::~CloneSource()
+{
+    if (origin_)
+        origin_->clones_.remove(this);
+}
+
+CloneSource *CloneSource::clone(uint64_t id)
+{
+    // do not clone a clone : clone the original instead
+    if (origin_)
+        return origin_->clone(id);
+    else
+        return nullptr;
+}
+
+void CloneSource::init()
+{
+    if (origin_ && origin_->mode_ > Source::UNINITIALIZED) {
+
+        // get the texture index from framebuffer of view, apply it to the surface
+        texturesurface_->setTextureIndex( origin_->texture() );
+
+        // create Frame buffer matching size of session
+        FrameBuffer *renderbuffer = new FrameBuffer( origin_->frame()->resolution(), true);
+
+        // set the renderbuffer of the source and attach rendering nodes
+        attach(renderbuffer);
+
+        // deep update to reorder
+        ++View::need_deep_update_;
+
+        // done init
+        Log::Info("Source %s cloning source %s.", name().c_str(), origin_->name().c_str() );
+    }
+}
+
+void CloneSource::setActive (bool on)
+{
+    active_ = on;
+
+    groups_[View::RENDERING]->visible_ = active_;
+    groups_[View::GEOMETRY]->visible_ = active_;
+    groups_[View::LAYER]->visible_ = active_;
+
+    if (origin_) {
+        if ( mode_ > Source::UNINITIALIZED)
+            origin_->touch();
+
+        // change visibility of active surface (show preview of origin when inactive)
+        if (activesurface_) {
+            if (active_)
+                activesurface_->setTextureIndex(Resource::getTextureTransparent());
+            else
+                activesurface_->setTextureIndex(origin_->texture());
+        }
+    }
+}
+
+uint CloneSource::texture() const
+{
+    if (origin_ != nullptr)
+        return origin_->texture();
+    else
+        return Resource::getTextureBlack();
+}
+
+void CloneSource::accept(Visitor& v)
+{
+    Source::accept(v);
+    if (!failed())
+        v.visit(*this);
+}
+
+glm::ivec2 CloneSource::icon() const
+{
+    return glm::ivec2(ICON_SOURCE_CLONE);
+}
+
+std::string CloneSource::info() const
+{
+    return std::string("clone of '") + origin_->name() + "'";
+}
diff --git a/CloneSource.h b/CloneSource.h
new file mode 100644
index 0000000..4ee4c8a
--- /dev/null
+++ b/CloneSource.h
@@ -0,0 +1,39 @@
+#ifndef CLONESOURCE_H
+#define CLONESOURCE_H
+
+#include "Source.h"
+
+class CloneSource : public Source
+{
+    friend class Source;
+
+public:
+    ~CloneSource();
+
+    // 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;
+
+    CloneSource *clone(uint64_t id = 0) override;
+    inline void detach() { origin_ = nullptr; }
+    inline Source *origin() const { return origin_; }
+
+    glm::ivec2 icon() const override;
+    std::string info() const override;
+
+protected:
+    // only Source class can create new CloneSource via clone();
+    CloneSource(Source *origin, uint64_t id = 0);
+
+    void init() override;
+    Source *origin_;
+};
+
+
+#endif // CLONESOURCE_H
diff --git a/DeviceSource.cpp b/DeviceSource.cpp
index cefa8b0..2515166 100644
--- a/DeviceSource.cpp
+++ b/DeviceSource.cpp
@@ -25,16 +25,18 @@
 #include <gst/pbutils/pbutils.h>
 #include <gst/gst.h>
 
-#include "DeviceSource.h"
 
 #include "defines.h"
+#include "Log.h"
 #include "ImageShader.h"
 #include "ImageProcessingShader.h"
 #include "Resource.h"
 #include "Decorations.h"
 #include "Stream.h"
 #include "Visitor.h"
-#include "Log.h"
+#include "CloneSource.h"
+
+#include "DeviceSource.h"
 
 #ifndef NDEBUG
 #define DEVICE_DEBUG
diff --git a/ImGuiVisitor.cpp b/ImGuiVisitor.cpp
index 6eb24ab..4c2ca27 100644
--- a/ImGuiVisitor.cpp
+++ b/ImGuiVisitor.cpp
@@ -42,6 +42,7 @@
 #include "ImageProcessingShader.h"
 #include "MediaPlayer.h"
 #include "MediaSource.h"
+#include "CloneSource.h"
 #include "SessionSource.h"
 #include "PatternSource.h"
 #include "DeviceSource.h"
diff --git a/InfoVisitor.cpp b/InfoVisitor.cpp
index f057a57..02139e6 100644
--- a/InfoVisitor.cpp
+++ b/InfoVisitor.cpp
@@ -38,6 +38,7 @@
 #include "ImageProcessingShader.h"
 #include "MediaPlayer.h"
 #include "MediaSource.h"
+#include "CloneSource.h"
 #include "SessionSource.h"
 #include "PatternSource.h"
 #include "DeviceSource.h"
diff --git a/Mixer.cpp b/Mixer.cpp
index b1d360d..7c034cb 100644
--- a/Mixer.cpp
+++ b/Mixer.cpp
@@ -42,6 +42,7 @@
 #include "SessionCreator.h"
 #include "SessionVisitor.h"
 #include "SessionSource.h"
+#include "CloneSource.h"
 #include "MediaSource.h"
 #include "PatternSource.h"
 #include "DeviceSource.h"
diff --git a/SessionCreator.cpp b/SessionCreator.cpp
index 82fb588..a89fd64 100644
--- a/SessionCreator.cpp
+++ b/SessionCreator.cpp
@@ -25,6 +25,7 @@
 #include "Primitives.h"
 #include "Mesh.h"
 #include "Source.h"
+#include "CloneSource.h"
 #include "MediaSource.h"
 #include "SessionSource.h"
 #include "StreamSource.h"
diff --git a/SessionVisitor.cpp b/SessionVisitor.cpp
index 02e244f..3eab5c2 100644
--- a/SessionVisitor.cpp
+++ b/SessionVisitor.cpp
@@ -28,6 +28,7 @@ using namespace tinyxml2;
 #include "Scene.h"
 #include "Decorations.h"
 #include "Source.h"
+#include "CloneSource.h"
 #include "MediaSource.h"
 #include "Session.h"
 #include "SessionSource.h"
diff --git a/Source.cpp b/Source.cpp
index 5a97e88..0cfc40c 100644
--- a/Source.cpp
+++ b/Source.cpp
@@ -24,6 +24,7 @@
 #include <glm/gtc/matrix_transform.hpp>
 
 #include "defines.h"
+#include "Log.h"
 #include "FrameBuffer.h"
 #include "Decorations.h"
 #include "Resource.h"
@@ -32,9 +33,9 @@
 #include "ImageProcessingShader.h"
 #include "BaseToolkit.h"
 #include "SystemToolkit.h"
-#include "Log.h"
 #include "MixingGroup.h"
 
+#include "CloneSource.h"
 #include "Source.h"
 
 SourceCore::SourceCore()
@@ -901,104 +902,4 @@ void Source::clearMixingGroup()
 }
 
 
-CloneSource *Source::clone(uint64_t id)
-{
-    CloneSource *s = new CloneSource(this, id);
-
-    clones_.push_back(s);
-
-    return s;
-}
-
-
-CloneSource::CloneSource(Source *origin, uint64_t id) : Source(id), origin_(origin)
-{
-    name_ = origin->name();
-    // set symbol
-    symbol_ = new Symbol(Symbol::CLONE, glm::vec3(0.75f, 0.75f, 0.01f));
-    symbol_->scale_.y = 1.5f;
-}
-
-CloneSource::~CloneSource()
-{
-    if (origin_)
-        origin_->clones_.remove(this);
-}
-
-CloneSource *CloneSource::clone(uint64_t id)
-{
-    // do not clone a clone : clone the original instead
-    if (origin_)
-        return origin_->clone(id);
-    else
-        return nullptr;
-}
-
-void CloneSource::init()
-{
-    if (origin_ && origin_->mode_ > Source::UNINITIALIZED) {
-
-        // get the texture index from framebuffer of view, apply it to the surface
-        texturesurface_->setTextureIndex( origin_->texture() );
-
-        // create Frame buffer matching size of session
-        FrameBuffer *renderbuffer = new FrameBuffer( origin_->frame()->resolution(), true);
-
-        // set the renderbuffer of the source and attach rendering nodes
-        attach(renderbuffer);
-
-        // deep update to reorder
-        ++View::need_deep_update_;
-
-        // done init
-        Log::Info("Source %s cloning source %s.", name().c_str(), origin_->name().c_str() );
-    }
-}
-
-void CloneSource::setActive (bool on)
-{
-    active_ = on;
-
-    groups_[View::RENDERING]->visible_ = active_;
-    groups_[View::GEOMETRY]->visible_ = active_;
-    groups_[View::LAYER]->visible_ = active_;
-
-    if (origin_) {
-        if ( mode_ > Source::UNINITIALIZED)
-            origin_->touch();
-
-        // change visibility of active surface (show preview of origin when inactive)
-        if (activesurface_) {
-            if (active_)
-                activesurface_->setTextureIndex(Resource::getTextureTransparent());
-            else
-                activesurface_->setTextureIndex(origin_->texture());
-        }
-    }
-}
-
-uint CloneSource::texture() const
-{
-    if (origin_ != nullptr)
-        return origin_->texture();
-    else
-        return Resource::getTextureBlack();
-}
-
-void CloneSource::accept(Visitor& v)
-{
-    Source::accept(v);
-    if (!failed())
-        v.visit(*this);
-}
-
-glm::ivec2 CloneSource::icon() const
-{
-    return glm::ivec2(ICON_SOURCE_CLONE);
-}
-
-std::string CloneSource::info() const
-{
-    return std::string("clone of '") + origin_->name() + "'";
-}
 
diff --git a/Source.h b/Source.h
index b226f02..863c645 100644
--- a/Source.h
+++ b/Source.h
@@ -328,37 +328,6 @@ protected:
 };
 
 
-class CloneSource : public Source
-{
-    friend class Source;
-
-public:
-    ~CloneSource();
-
-    // 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;
-
-    CloneSource *clone(uint64_t id = 0) override;
-    inline void detach() { origin_ = nullptr; }
-    inline Source *origin() const { return origin_; }
-
-    glm::ivec2 icon() const override;
-    std::string info() const override;
-
-protected:
-    // only Source class can create new CloneSource via clone();
-    CloneSource(Source *origin, uint64_t id = 0);
-
-    void init() override;
-    Source *origin_;
-};
 
 
 #endif // SOURCE_H
diff --git a/UserInterfaceManager.cpp b/UserInterfaceManager.cpp
index eabea6b..f22eb45 100644
--- a/UserInterfaceManager.cpp
+++ b/UserInterfaceManager.cpp
@@ -76,6 +76,7 @@ using namespace std;
 #include "Selection.h"
 #include "FrameBuffer.h"
 #include "MediaPlayer.h"
+#include "CloneSource.h"
 #include "MediaSource.h"
 #include "SessionSource.h"
 #include "PatternSource.h"