silentfilesource.h

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/*
    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 <cstring>
#include "ardour/audiofilesource.h"

namespace ARDOUR {

class LIBARDOUR_API SilentFileSource : public AudioFileSource {
public:
        int update_header (framepos_t /*when*/, struct tm&, time_t) { return 0; }
        int flush_header () { return 0; }
        float sample_rate () const { return _sample_rate; }

        void set_length (framecnt_t len) { _length = len; }
        void flush () {}

        bool destructive() const { return false; }
        bool can_be_analysed() const { return false; }

        bool clamped_at_unity() const { return false; }

protected:
        void close() {}
        friend class SourceFactory;

        SilentFileSource (Session& s, const XMLNode& x, framecnt_t len, float srate)
                : Source (s, x)
                , AudioFileSource (s, x, false)
                , _sample_rate(srate)
        {
                _length = len;
        }

        framecnt_t read_unlocked (Sample *dst, framepos_t /*start*/, framecnt_t cnt) const {
                memset (dst, 0, sizeof (Sample) * cnt);
                return cnt;
        }

        framecnt_t write_unlocked (Sample */*dst*/, framecnt_t /*cnt*/) { return 0; }

        void set_header_timeline_position () {}

        int read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t /*start*/, framecnt_t /*cnt*/,
                                 double /*frames_per_pixel*/, framecnt_t /*fpp*/) const {
                memset (peaks, 0, sizeof (PeakData) * npeaks);
                return 0;
        }

        float _sample_rate;
};

} // namespace ARDOUR

#endif /* __ardour_audiofilesource_h__ */