livetrax/libs/evoral/evoral/SMFReader.h

/*
 * Copyright (C) 2008-2011 David Robillard <d@drobilla.net>
 *
 * 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 EVORAL_SMF_READER_HPP
#define EVORAL_SMF_READER_HPP

#include <exception>
#include <stdexcept>
#include <string>
#include <inttypes.h>

#include "evoral/visibility.h"

namespace Evoral {


/** Standard MIDI File (Type 0) Reader
 *
 * Currently this only reads SMF files with tempo-based timing.
 */
class LIBEVORAL_API SMFReader {
public:
	class PrematureEOF : public std::exception {
		const char* what() const throw() { return "Unexpected end of file"; }
	};
	class CorruptFile : public std::exception {
		const char* what() const throw() { return "Corrupted file"; }
	};
	class UnsupportedTime : public std::exception {
		const char* what() const throw() { return "Unsupported time stamp type (SMPTE)"; }
	};

	SMFReader(const std::string& filename="");
	~SMFReader();

	bool open(const std::string& filename) throw (std::logic_error, UnsupportedTime);

	bool seek_to_track(unsigned track) throw (std::logic_error);

	const std::string& filename() const { return _filename; };

	uint16_t type()       const { return _type; }
	uint16_t ppqn()       const { return _ppqn; }
	uint16_t num_tracks() const { return _num_tracks; }

	int read_event(size_t    buf_len,
	               uint8_t*  buf,
	               uint32_t* ev_size,
	               uint32_t* ev_delta_time)
		throw (std::logic_error, PrematureEOF, CorruptFile);

	void close();

	static uint32_t read_var_len(FILE* fd) throw (PrematureEOF);

protected:
	/** size of SMF header, including MTrk chunk header */
	static const uint32_t HEADER_SIZE = 22;

	std::string _filename;
	FILE*       _fd;
	uint16_t    _type;
	uint16_t    _ppqn;
	uint16_t    _num_tracks;
	uint32_t    _track;
	uint32_t    _track_size;
};


} // namespace Evoral

#endif // EVORAL_SMF_READER_HPP