use SilentFileSource when sources cannot be found

git-svn-id: svn://localhost/ardour2/trunk@1424 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 66 insertions, 0 deletions

diff --git a/libs/ardour/ardour/silentfilesource.h b/libs/ardour/ardour/silentfilesource.h
new file mode 100644
index 0000000000..92ef076a9b
--- /dev/null
+++ b/libs/ardour/ardour/silentfilesource.h
@@ -0,0 +1,66 @@
+/*
+    Copyright (C) 2007 Paul Davis 
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __ardour_silentfilesource_h__ 
+#define __ardour_silentfilesource_h__
+
+#include <ardour/audiofilesource.h>
+
+namespace ARDOUR {
+
+class SilentFileSource : public AudioFileSource {
+  public:
+	virtual ~SilentFileSource ();
+
+	int update_header (nframes_t when, struct tm&, time_t) { return 0; }
+	int flush_header () { return 0; }
+	float sample_rate () const { return _sample_rate; }
+
+	void set_length (nframes_t len);
+	
+ 	int read_peaks (PeakData *peaks, nframes_t npeaks, nframes_t start, nframes_t cnt, double samples_per_unit) const {
+		memset (peaks, 0, sizeof (PeakData) * npeaks);
+		return 0;
+	}
+
+	bool destructive() const { return false; }
+
+  protected:
+
+	float         _sample_rate;
+
+	SilentFileSource (Session&, const XMLNode&, nframes_t nframes, float sample_rate);
+
+	friend class SourceFactory;
+
+	nframes_t read_unlocked (Sample *dst, nframes_t start, nframes_t cnt) const {
+		memset (dst, 0, sizeof (Sample) * cnt);
+		return cnt;
+	}
+
+	nframes_t write_unlocked (Sample *dst, nframes_t cnt) { return 0; }
+
+	void set_header_timeline_position () {}
+
+};
+
+} // namespace ARDOUR
+
+#endif /* __ardour_audiofilesource_h__ */
+