ardour/libs/evoral/src/LibSMF.cpp

#include "evoral/LibSMF.hpp"
#include "evoral/Event.hpp"
#include <cassert>

#include <iostream>

using namespace std;

namespace Evoral {


/** 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
 */
template<typename Time>
int
LibSMF<Time>::open(const std::string& path)
{
	if (_smf) { 
		smf_delete(_smf);
	}
	
	_smf = smf_load(path.c_str());
	if (!_smf) {
		_smf = smf_new();
		smf_set_ppqn(_smf, _ppqn);
		
		if(_smf == NULL) {
			return -1;
		}
	}
		
	_smf_track = smf_get_track_by_number(_smf, 1);
	assert(_smf_track);

	cerr << "number of events: " << _smf_track->number_of_events << endl;
	
	_empty = !(_smf_track->number_of_events > 0);
	
	return 0;
}

template<typename Time>
void
LibSMF<Time>::close()
{
	assert(false);
	if (_smf) {
		smf_save(_smf, _path.c_str());
		smf_delete(_smf);
		_smf = 0;
		_smf_track = 0;
	}
}

template<typename Time>
void
LibSMF<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
LibSMF<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
LibSMF<Time>::append_event_unlocked(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
LibSMF<Time>::begin_write(FrameTime start_frame)
{
	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
LibSMF<Time>::end_write()
{
	smf_save(_smf, _path.c_str());
}

template class LibSMF<double>;

} // namespace Evoral