srcfilesource.h

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/*
 * Copyright (C) 2014-2015 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2014-2017 Paul Davis <paul@linuxaudiosystems.com>
 *
 * 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.
 */
 
#pragma once
 
#include <cstring>
#include <samplerate.h>
 
#include "ardour/libardour_visibility.h"
#include "ardour/audiofilesource.h"
#include "ardour/session.h"
 
namespace ARDOUR {
 
class LIBARDOUR_API SrcFileSource : public AudioFileSource {
public:
        SrcFileSource (Session&, std::shared_ptr<AudioFileSource>, SrcQuality srcq = SrcQuality(SrcQuick));
        ~SrcFileSource ();
 
        int  update_header (samplepos_t /*when*/, struct tm&, time_t) { return 0; }
        int  flush_header () { return 0; }
        void flush () { }
        void set_header_natural_position () {};
        void set_length (samplecnt_t /*len*/) {};
 
        float sample_rate () const { return _session.nominal_sample_rate(); }
 
        timepos_t natural_position() const { return _source->natural_position().scale (_ratio); }
        samplecnt_t readable_length_samples() const { assert (_source->length().time_domain() == Temporal::AudioTime); return _source->length().samples () * _ratio; }
        timepos_t length () const { assert (_source->length().time_domain() == Temporal::AudioTime); return timepos_t ((samplepos_t) (_source->length().samples () * _ratio)); }
 
        bool can_be_analysed() const { return false; }
        bool clamped_at_unity() const { return false; }
 
protected:
        void close ();
        samplecnt_t read_unlocked (Sample *dst, samplepos_t start, samplecnt_t cnt) const;
        samplecnt_t write_unlocked (Sample const */*src*/, samplecnt_t /*cnt*/) { return 0; }
 
        int read_peaks_with_fpp (PeakData *peaks, samplecnt_t npeaks, samplepos_t /*start*/, samplecnt_t /*cnt*/,
                                 double /*samples_per_unit*/, samplecnt_t /*fpp*/) const {
                memset (peaks, 0, sizeof (PeakData) * npeaks);
                return 0;
        }
 
private:
        static const uint32_t max_blocksize;
        std::shared_ptr<AudioFileSource> _source;
 
        mutable SRC_STATE* _src_state;
        mutable SRC_DATA   _src_data;
 
        mutable Sample* _src_buffer;
        mutable samplepos_t _source_position;
        mutable samplepos_t _target_position;
        mutable double _fract_position;
 
        double _ratio;
        samplecnt_t src_buffer_size;
};
 
} // namespace ARDOUR