diff --git a/src/abstractreader.h b/src/abstractreader.h
--- a/src/abstractreader.h
+++ b/src/abstractreader.h
@@ -49,6 +49,8 @@ public:
     /// None of the current readers support X channel at the moment
     bool hasX() const final { return false; };
 
+    unsigned numChannels() const;
+
 signals:
     // TODO: should we keep this?
     void numOfChannelsChanged(unsigned);
@@ -65,6 +67,7 @@ public slots:
 protected:
     QIODevice* _device;
     bool paused;
+    unsigned _numChannels;
 };
 
 #endif // ABSTRACTREADER_H