- virtual bool pass () = 0;
- virtual bool seek (double);
- virtual void seek_back () {}
- virtual void seek_forward () {}
-
- boost::signals2::signal<void()> OutputChanged;
+ /** Perform one decode pass of the content, which may or may not
+ * cause the object to emit some data.
+ */
+ virtual void pass () = 0;
+ virtual bool done () const = 0;