--- a
+++ b/src/ohsndrcv.hxx
@@ -0,0 +1,57 @@
+/* Copyright (C) 2015 J.F.Dockes
+ *   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 2 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, write to the
+ *   Free Software Foundation, Inc.,
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+#ifndef _OHSNDRCV_H_X_INCLUDED_
+#define _OHSNDRCV_H_X_INCLUDED_
+
+/** 
+ * This implements a special mode of operation for upmpdcli where a
+ * Songcast Sender is created (playing the current playlist) and we
+ * switch to Receiver mode. Other Receivers may then be connected for
+ * synchronized multiroom playing.
+ *
+ * On entering the mode, the following operations are performed.
+ *  - Tell MPD to stop playing.
+ *  - Start another MPD process which one FIFO output.
+ *  - Start a Songcast Sender (uxsender) process, playing from the
+ *    FIFO. 
+ *  - (The two above steps are implement by an external script)
+ *  - Copy the playlist to the new MPD, and play approximately from
+ *    where we stopped.
+ *  - Switch to receiver mode and play from the just created Sender.
+ * At this point other Receivers may be connected.
+ *
+ * The mode is entered by selecting the SenderReceiver source in
+ * OHProduct::setSource. This is a slight abuse of the function, but
+ * allows controlling this from any CP implementing setSource.
+ */
+
+class UpMpd;
+
+class SenderReceiver {
+public:
+    SenderReceiver(UpMpd *dev);
+    ~SenderReceiver();
+    bool start(int seekms);
+    bool stop();
+
+    class Internal;
+private:
+    Internal *m;
+};
+
+
+#endif /* _OHSNDRCV_H_X_INCLUDED_ */