diff --git a/ActionManager.cpp b/ActionManager.cpp
index c13969e..7ff6a4d 100644
--- a/ActionManager.cpp
+++ b/ActionManager.cpp
@@ -185,10 +185,12 @@ void Action::restore(uint target)
 
 void Action::snapshot(const std::string &label)
 {
-    // ignore if locked or if no label is given
-    if (locked_ || label.empty())
+    // ignore if locked
+    if (locked_)
         return;
 
+    std::string snap_label = BaseToolkit::uniqueName(label, labels());
+
     // create snapshot id
     u_int64_t id = BaseToolkit::uniqueId();
 
@@ -197,10 +199,10 @@ void Action::snapshot(const std::string &label)
     se->snapshots()->keys_.push_back(id);
 
     // threaded capture state of current session
-    std::thread(captureMixerSession, se->snapshots()->xmlDoc_, SNAPSHOT_NODE(id), label).detach();
+    std::thread(captureMixerSession, se->snapshots()->xmlDoc_, SNAPSHOT_NODE(id), snap_label).detach();
 
 #ifdef ACTION_DEBUG
-    Log::Info("Snapshot stored %d '%s'", id, label.c_str());
+    Log::Info("Snapshot stored %d '%s'", id, snap_label.c_str());
 #endif
 }
 
@@ -252,6 +254,17 @@ std::list<uint64_t> Action::snapshots() const
     return Mixer::manager().session()->snapshots()->keys_;
 }
 
+std::list<std::string> Action::labels() const
+{
+    std::list<std::string> names;
+
+    tinyxml2::XMLDocument *doc = Mixer::manager().session()->snapshots()->xmlDoc_;
+    for ( XMLElement *snap = doc->FirstChildElement(); snap ; snap = snap->NextSiblingElement() )
+        names.push_back( snap->Attribute("label"));
+
+    return names;
+}
+
 std::string Action::label(uint64_t snapshotid) const
 {
     std::string label = "";
diff --git a/ActionManager.h b/ActionManager.h
index a00612e..b8c65b9 100644
--- a/ActionManager.h
+++ b/ActionManager.h
@@ -38,7 +38,7 @@ public:
     FrameBufferImage *thumbnail (uint s) const;
 
     // Snapshots
-    void snapshot (const std::string &label);
+    void snapshot (const std::string &label = "");
 
     std::list<uint64_t> snapshots () const;
     uint64_t currentSnapshot () const { return snapshot_id_; }
@@ -49,6 +49,7 @@ public:
     void remove  (uint64_t snapshotid = 0);
 
     std::string label (uint64_t snapshotid) const;
+    std::list<std::string> labels () const;
     void setLabel (uint64_t snapshotid, const std::string &label);
     FrameBufferImage *thumbnail (uint64_t snapshotid) const;
 
diff --git a/BaseToolkit.cpp b/BaseToolkit.cpp
index 910cfb2..6b00a34 100644
--- a/BaseToolkit.cpp
+++ b/BaseToolkit.cpp
@@ -5,6 +5,7 @@
 #include <sstream>
 #include <list>
 #include <iomanip>
+#include <algorithm>
 
 #include <locale>
 #include <unicode/ustream.h>
@@ -18,6 +19,33 @@ uint64_t BaseToolkit::uniqueId()
 }
 
 
+
+std::string BaseToolkit::uniqueName(const std::string &basename, std::list<std::string> existingnames)
+{
+    std::string tentativename = basename;
+    int count = 1;
+    int max = 100;
+
+    // while tentativename can be found in the list of existingnames
+    while ( std::find( existingnames.begin(), existingnames.end(), tentativename ) != existingnames.end() )
+    {
+        for( auto it = existingnames.cbegin(); it != existingnames.cend(); ++it) {
+            if ( it->find(tentativename) != std::string::npos)
+                ++count;
+        }
+
+        if (count > 1)
+            tentativename = basename + "_" + std::to_string( count );
+        else
+            tentativename += "_";
+
+        if ( --max < 0 ) // for safety only, should never be needed
+            break;
+    }
+
+    return tentativename;
+}
+
 // Using ICU transliteration :
 // https://unicode-org.github.io/icu/userguide/transforms/general/#icu-transliterators
 
diff --git a/BaseToolkit.h b/BaseToolkit.h
index 29562dc..ecef3b0 100644
--- a/BaseToolkit.h
+++ b/BaseToolkit.h
@@ -1,6 +1,7 @@
 #ifndef BASETOOLKIT_H
 #define BASETOOLKIT_H
 
+#include <list>
 #include <string>
 
 namespace BaseToolkit
@@ -9,6 +10,9 @@ namespace BaseToolkit
 // get integer with unique id
 uint64_t uniqueId();
 
+// proposes a name that is not already in the list
+std::string uniqueName(const std::string &basename, std::list<std::string> existingnames);
+
 // get a transliteration to Latin of any string
 std::string transliterate(std::string input);
 
@@ -18,6 +22,7 @@ std::string byte_to_string(long b);
 // get a string to display bit size with unit Kbit, MBit, Gbit, Tbit
 std::string bits_to_string(long b);
 
+
 }
 
 
diff --git a/Mixer.cpp b/Mixer.cpp
index 4e20dbd..a82b4a2 100644
--- a/Mixer.cpp
+++ b/Mixer.cpp
@@ -18,6 +18,7 @@
 #include "Log.h"
 #include "View.h"
 #include "ImageShader.h"
+#include "BaseToolkit.h"
 #include "SystemToolkit.h"
 #include "SessionCreator.h"
 #include "SessionVisitor.h"
@@ -251,7 +252,10 @@ Source * Mixer::createSourceRender()
     s->setSession(session_);
 
     // propose a new name based on session name
-    s->setName(SystemToolkit::base_filename(session_->filename()));
+    if ( !session_->filename().empty() )
+        s->setName(SystemToolkit::base_filename(session_->filename()));
+    else
+        s->setName("Output");
 
     return s;
 }
@@ -263,8 +267,7 @@ Source * Mixer::createSourceStream(const std::string &gstreamerpipeline)
     s->setDescription(gstreamerpipeline);
 
     // propose a new name based on pattern name
-    std::string name = gstreamerpipeline.substr(0, gstreamerpipeline.find(" "));
-    s->setName(name);
+    s->setName( gstreamerpipeline.substr(0, gstreamerpipeline.find(" ")) );
 
     return s;
 }
@@ -289,8 +292,7 @@ Source * Mixer::createSourceDevice(const std::string &namedevice)
     Source *s = Device::manager().createSource(namedevice);
 
     // propose a new name based on pattern name
-    std::string name = namedevice.substr(0, namedevice.find(" "));
-    s->setName(name);
+    s->setName( namedevice.substr(0, namedevice.find(" ")) );
 
     return s;
 }
@@ -333,23 +335,17 @@ Source * Mixer::createSourceClone(const std::string &namesource)
         origin = current_source_;
 
     // have an origin, can clone it
-    if (origin != session_->end()) {
-
+    if (origin != session_->end())
         // create a source
         s = (*origin)->clone();
 
-        // propose new name (this automatically increments name)
-        s->setName((*origin)->name());
-    }
-
     return s;
 }
 
 void Mixer::addSource(Source *s)
 {
-    if (s != nullptr) {
+    if (s != nullptr)
         candidate_sources_.push_back(s);
-    }
 }
 
 void Mixer::insertSource(Source *s, View::Mode m)
@@ -656,16 +652,7 @@ void Mixer::renameSource(Source *s, const std::string &newname)
         if ( !newname.empty() )
             tentativename = newname;
 
-        // search for a source of the name 'tentativename'
-        std::string basename = tentativename;
-        int count = 1;
-        for( auto it = session_->begin(); it != session_->end(); it++){
-            if ( s->id() != (*it)->id() && (*it)->name() == tentativename )
-                tentativename = basename + std::to_string( ++count );
-        }
-
-//        std::list<std::string> names = session_->getNameList();
-
+        tentativename = BaseToolkit::uniqueName(tentativename, session_->getNameList());
 
         // ok to rename
         s->setName(tentativename);
diff --git a/Source.cpp b/Source.cpp
index 4bd4193..e794527 100644
--- a/Source.cpp
+++ b/Source.cpp
@@ -316,7 +316,8 @@ Source::~Source()
 
 void Source::setName (const std::string &name)
 {
-    name_ = BaseToolkit::transliterate(name);
+    if (!name.empty())
+        name_ = BaseToolkit::transliterate(name);
 
     initials_[0] = std::toupper( name_.front(), std::locale("C") );
     initials_[1] = std::toupper( name_.back(), std::locale("C") );
@@ -817,6 +818,7 @@ CloneSource *Source::clone(uint64_t id)
 
 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;
diff --git a/UserInterfaceManager.cpp b/UserInterfaceManager.cpp
index bfd0be8..9440983 100644
--- a/UserInterfaceManager.cpp
+++ b/UserInterfaceManager.cpp
@@ -259,7 +259,7 @@ void UserInterface::handleKeyboard()
             }
         }
         else if (ImGui::IsKeyPressed( GLFW_KEY_Y )) {
-            Action::manager().snapshot( SystemToolkit::date_time_string() );
+            Action::manager().snapshot( "Snap" );
         }
         else if (ImGui::IsKeyPressed( GLFW_KEY_Z )) {
             if (shift_modifier_active)
@@ -807,7 +807,7 @@ void UserInterface::showMenuEdit()
     if ( ImGui::MenuItem( ICON_FA_REDO "  Redo", CTRL_MOD "Shift+Z") )
         Action::manager().redo();
     if ( ImGui::MenuItem( ICON_FA_STAR "+ Snapshot", CTRL_MOD "Y") )
-        Action::manager().snapshot( SystemToolkit::date_time_string() );
+        Action::manager().snapshot( "Snap" );
 }
 
 void UserInterface::showMenuFile()
@@ -3236,7 +3236,7 @@ void Navigator::RenderMainPannelVimix()
         // right buttons
         ImGui::SetCursorPos( ImVec2( pannel_width_ IMGUI_RIGHT_ALIGN, pos_top.y ));
         if ( ImGuiToolkit::IconButton( ICON_FA_STAR "+"))
-            Action::manager().snapshot( SystemToolkit::date_time_string() );
+            Action::manager().snapshot( "Snap" );
         if (ImGui::IsItemHovered())
             ImGuiToolkit::ToolTip("Take Snapshot ", CTRL_MOD "Y");