MidiImport.h

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/*
 * MidiImport.h - support for importing MIDI files
 *
 * Copyright (c) 2005-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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 (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef _MIDI_IMPORT_H
#define _MIDI_IMPORT_H
 
#include <cstdint>
#include <QString>
 
#include "MidiEvent.h"
#include "ImportFilter.h"
 
namespace lmms
{
 
 
class MidiImport : public ImportFilter
{
    Q_OBJECT
public:
    MidiImport(const QString& file);
    ~MidiImport() override = default;
    gui::PluginView* instantiateView(QWidget*) override { return nullptr; }
 
private:
    bool tryImport(TrackContainer* tc) override;
    bool readSMF(TrackContainer* tc);
    bool readRIFF(TrackContainer* tc);
    bool readTrack(int track_end, QString& track_name);
    void error();
 
    inline std::int32_t read32LE()
    {
        std::int32_t value = readByte();
        value |= readByte() << 8;
        value |= readByte() << 16;
        value |= readByte() << 24;
        return value;
    }
 
    inline std::int32_t readVar()
    {
        std::int32_t c = readByte();
        std::int32_t value = c & 0x7f;
        if (c & 0x80)
        {
            c = readByte();
            value = (value << 7) | (c & 0x7f);
            if (c & 0x80)
            {
                c = readByte();
                value = (value << 7) | (c & 0x7f);
                if (c & 0x80)
                {
                    c = readByte();
                    value = (value << 7) | c;
                    if (c & 0x80) { return -1; }
                }
            }
        }
        return !file().atEnd() ? value : -1;
    }
 
    inline void skip(unsigned num_bytes) { while (num_bytes--) { readByte(); } }
 
    int m_timingDivision = 0;
};
 
 
} // namespace lmms
 
#endif