resampled_source.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_resampled_source_h__
#define __ardour_resampled_source_h__

#include <samplerate.h>

#include "ardour/libardour_visibility.h"
#include "ardour/types.h"
#include "ardour/importable_source.h"

namespace ARDOUR {

class LIBARDOUR_API ResampledImportableSource : public ImportableSource
{
  public:
        ResampledImportableSource (boost::shared_ptr<ImportableSource>, framecnt_t rate, SrcQuality);

        ~ResampledImportableSource ();

        framecnt_t read (Sample* buffer, framecnt_t nframes);
        float      ratio() const { return src_data.src_ratio; }
        uint32_t   channels() const { return source->channels(); }
        framecnt_t length() const { return source->length(); }
        framecnt_t samplerate() const { return source->samplerate(); }
        void       seek (framepos_t);
        framepos_t natural_position() const;

        bool clamped_at_unity () const {
                /* resampling may generate inter-sample peaks with magnitude > 1 */
                return false;
        }

        static const uint32_t blocksize;

   private:
        boost::shared_ptr<ImportableSource> source;
        float* input;
        int _src_type;
        SRC_STATE*      src_state;
        SRC_DATA        src_data;
};

}

#endif /* __ardour_resampled_source_h__ */