no more noise during startup.

diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index b18d5e1af26834ee2d6325b2d6c16abf66b3f7a7..a92e7d45249ef5aff1ae600369e734bd2a27379a 100644 (file)
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -205,7 +205,12 @@ AudioEngine::process_callback (pframes_t nframes)
                if (_session) {
                        Xrun();
                }
-               _processed_frames = next_processed_frames;
+               /* really only JACK requires this
+                * (other backends clear the output buffers
+                * before the process_callback. it may even be 
+                * jack/alsa only). but better safe than sorry.
+                */
+               PortManager::silence_physical (nframes);
                return 0;
        }