livetrax/libs/evoral/src/SMF.cpp

/* This file is part of Evoral.
 * Copyright (C) 2008 Dave Robillard <http://drobilla.net>
 * Copyright (C) 2000-2008 Paul Davis
 * Author: Hans Baier
 * 
 * Evoral 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.
 * 
 * Evoral 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 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 St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <cassert>
#include <iostream>
#include "evoral/Event.hpp"
#include "evoral/SMF.hpp"
#include "libsmf/smf.h"

using namespace std;

namespace Evoral {

template<typename Time>
SMF<Time>::~SMF()
{	
	if (_smf) {
		smf_delete(_smf);
		_smf = 0;
		_smf_track = 0;
	} 
}

/** Attempt to open the SMF file for reading and writing.
 *
 * Currently SMF is always read/write.
 *
 * \return  0 on success
 *         -1 if the file can not be opened or created
 *         -2 if the file exists but specified track does not
 */
template<typename Time>
int
SMF<Time>::open(const std::string& path, bool create, int track) THROW_FILE_ERROR
{
	if (_smf) { 
		smf_delete(_smf);
	}
	
	_path = path;
	
	_smf = smf_load(_path.c_str());
	if (!_smf) {
		if (!create) {
			return -1;
		}

		_smf = smf_new();
		if (smf_set_ppqn(_smf, _ppqn) != 0) {
			throw FileError();
		}
		
		if (_smf == NULL) {
			return -1;
		}
		
		for (int i = 0; i < track; ++i) {
			_smf_track = smf_track_new();
			assert(_smf_track);
			smf_add_track(_smf, _smf_track);
		}
	}
		
	_smf_track = smf_get_track_by_number(_smf, track);
	if (!_smf_track)
		return -2;

	cerr << "Track " << track << " # events: " << _smf_track->number_of_events << endl;
	
	_empty = !(_smf_track->number_of_events > 0);
	
	return 0;
}

template<typename Time>
void
SMF<Time>::close() THROW_FILE_ERROR
{
	if (_smf) {
		if (smf_save(_smf, _path.c_str()) != 0) {
			throw FileError();
		}
		smf_delete(_smf);
		_smf = 0;
		_smf_track = 0;
	}
}

template<typename Time>
void
SMF<Time>::seek_to_start() const
{
	smf_rewind(_smf);
}

/** Read an event from the current position in file.
 *
 * File position MUST be at the beginning of a delta time, or this will die very messily.
 * ev.buffer must be of size ev.size, and large enough for the event.  The returned event
 * will have it's time field set to it's delta time, in SMF tempo-based ticks, using the
 * rate given by ppqn() (it is the caller's responsibility to calculate a real time).
 *
 * \a size should be the capacity of \a buf.  If it is not large enough, \a buf will
 * be freed and a new buffer allocated in its place, the size of which will be placed
 * in size.
 *
 * Returns event length (including status byte) on success, 0 if event was
 * skipped (eg a meta event), or -1 on EOF (or end of track).
 */
template<typename Time>
int
SMF<Time>::read_event(uint32_t* delta_t, uint32_t* size, uint8_t** buf) const
{
	smf_event_t *event;
	
	assert(delta_t);
	assert(size);
	assert(buf);
	
    if ((event = smf_get_next_event(_smf)) != NULL) {
    	if (smf_event_is_metadata(event)) {
    		return 0;
    	}
    	*delta_t = event->delta_time_pulses;
    	
    	int event_size = event->midi_buffer_length;
    	assert(event_size > 0);
    		
    	// Make sure we have enough scratch buffer
    	if (*size < (unsigned)event_size) {
    		*buf = (uint8_t*)realloc(*buf, event_size);
    	}
    	memcpy(*buf, event->midi_buffer, size_t(event_size));
    	*size = event_size;
    	
    	return event_size;
    } else {
    	return -1;
    }
}

template<typename Time>
void
SMF<Time>::append_event_delta(uint32_t delta_t, const Event<Time>& ev)
{
	assert(ev.size() > 0);
	
	smf_event_t *event;

	event = smf_event_new_from_pointer((void *) ev.buffer(), int(ev.size()));
	assert(event != NULL);
	
	memcpy(event->midi_buffer, ev.buffer(), ev.size());
	
	assert(_smf_track);
	smf_track_add_event_delta_pulses (_smf_track, event, int(delta_t));
	_last_ev_time = ev.time();
	
	if (ev.size() > 0) {
		_empty = false;
	}
}

template<typename Time>
void
SMF<Time>::begin_write()
{
	assert(_smf_track);
	smf_track_delete(_smf_track);
	
	_smf_track = smf_track_new();
	assert(_smf_track);
	
	smf_add_track(_smf, _smf_track);
	assert(_smf->number_of_tracks == 1);
	
	_last_ev_time = 0;
}

template<typename Time>
void
SMF<Time>::end_write() THROW_FILE_ERROR
{
	if (smf_save(_smf, _path.c_str()) != 0)
		throw FileError();
}

template class SMF<double>;

} // namespace Evoral