added set single member functions to playback

src/playback_thread.h

@@ -34,6 +34,7 @@ private:
     unsigned int red, green, blue;
     unsigned int bright_, gamma_, saturation_;
     bool single_mode;
+    int current_filter;
 public:
     Playback(QObject *parent = 0);
     ~Playback();
@@ -54,6 +55,7 @@ public:
     void setStep();
     void setDisplayed(bool shown);
     void setIndexChanged(int pos);
+    void setSingleMode(bool val);
 signals:
     void procImage(const QImage image);
     void stopRecording();