resampled_source.h

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/*
 * Copyright (C) 2007-2017 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2009-2011 David Robillard <d@drobilla.net>
 * Copyright (C) 2010-2012 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2015-2019 Robin Gareus <robin@gareus.org>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 (std::shared_ptr<ImportableSource>, samplecnt_t rate, SrcQuality);
 
        ~ResampledImportableSource ();
 
        samplecnt_t read (Sample* buffer, samplecnt_t nframes);
        float       ratio() const { return _src_data.src_ratio; }
        uint32_t    channels() const { return source->channels(); }
        samplecnt_t length() const { return source->length(); }
        samplecnt_t samplerate() const { return source->samplerate(); }
        void        seek (samplepos_t);
        samplepos_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:
        std::shared_ptr<ImportableSource> source;
        float*          _input;
        int             _src_type;
        SRC_STATE*      _src_state;
        SRC_DATA        _src_data;
        bool            _end_of_input;
};
 
}
 
#endif /* __ardour_resampled_source_h__ */