path: root/drumgizmo/input/midifile/midifile.cc

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            dummy.cc
 *
 *  Sat Apr 30 21:11:54 CEST 2011
 *  Copyright 2011 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of DrumGizmo.
 *
 *  DrumGizmo 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.
 *
 *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include <stdlib.h>

#include <string>
#include <event.h>

#include <smf.h>

#include <midimapper.h>
#include <midimapparser.h>

#define NOTE_ON 0x90

class MidiFile {
public:
	MidiFile() = default;
	~MidiFile() = default;

	bool init(int instruments, char *inames[]);

	void setParm(std::string parm, std::string value);

	bool start();
	void stop();

	void pre();
	event_t *run(size_t pos, size_t len, size_t *nevents);
	void post();

private:
	smf_t *smf{nullptr};
	smf_event_t *cur_event{nullptr};

	MidiMapper mmap;

	// Parameters
	std::string filename;
	float speed{1.0};
	int track{-1}; // -1 is omni ie. all tracks
	std::string midimapfile;
	bool loop{false};
	double offset{0};
	double tempoOverrideBpm{-1}; // -1 is disabled.
};

bool MidiFile::init(int instruments, char *inames[])
{
	if(filename == "")
	{
		fprintf(stderr, "Missing midifile argument 'file'\n");
		return false;
	}

	if(midimapfile == "")
	{
		fprintf(stderr, "Missing midimapfile argument 'midimap'.\n");
		return false;
	}

	smf = smf_load(filename.c_str());

	if(!smf)
	{
		fprintf(stderr, "Could not open midifile '%s'.\n", filename.c_str());
		return false;
	}

	// Override tempo is supplied by the user
	if(tempoOverrideBpm > 0)
	{
		// Tempo change event format:
		// FF 51 03 tttttt - Set Tempo, in microseconds per MIDI quarter-note
		unsigned char midiData[] = { 0xff, 0x51, 0x03, 0, 0, 0 };

		unsigned int usecPerMinute = 60000000;
		unsigned int mpqn = usecPerMinute / tempoOverrideBpm;
		midiData[3] = (mpqn >> 0) & 0xff;
		midiData[4] = (mpqn >> 8) & 0xff;
		midiData[5] = (mpqn >> 16) & 0xff;

		smf_event_t* tempoChangeEvent =
			smf_event_new_from_pointer(midiData, sizeof(midiData));

		while(true)
		{
			smf_event_t* event = smf_peek_next_event(smf);

			// Skip all initial tempo events.
			if((!smf_event_is_metadata(event)) &&
			   (event->midi_buffer[1] == 0x51) && (event->midi_buffer[1] == 0x58))
			//if(smf_event_is_tempo_change_or_time_signature(event)) // only in latest smf
			{
				smf_skip_next_event(smf);
			}
			else
			{
				// No more tempo change event; stop searching.
				break;
			}
		}

		// Add tempo change event to all tracks.
		smf_track_t *track;
		unsigned int trackNumber = 1;
		while((track = smf_get_track_by_number(smf, trackNumber)))
		{
			smf_track_add_event_seconds(track, tempoChangeEvent, 0);
			++trackNumber;
		}
	}

	MidiMapParser p(midimapfile);
	if(p.parse())
	{
		fprintf(stderr, "Could not parse midimapfile '%s'.\n", midimapfile.c_str());
		return false;
	}
	mmap.midimap = p.midimap;

	for(int i = 0; i < instruments; ++i)
	{
		mmap.instrmap[inames[i]] = i;
	}

	return true;
}

void MidiFile::setParm(std::string parm, std::string value)
{
	if(parm == "file")
	{
		filename = value;
	}

	if(parm == "speed")
	{
		speed = atof(value.c_str());
	}

	if(parm == "track")
	{
		track = atoi(value.c_str());
	}

	if(parm == "midimap")
	{
		midimapfile = value;
	}

	if(parm == "loop")
	{
		loop = true;
	}

	if(parm == "tempo")
	{
		tempoOverrideBpm = atof(value.c_str());
	}
}

bool MidiFile::start()
{
	return true;
}

void MidiFile::stop()
{
}

void MidiFile::pre()
{
}

event_t *MidiFile::run(size_t pos, size_t len, size_t *nevents)
{
	event_t *evs = nullptr;
	size_t nevs = 0;

	double cur_max_time = (double)(pos + len) / (44100.0 / speed);
	cur_max_time -= offset;
	//  double cur_min_time = (double)(pos) / (44100.0 / speed);

	if(!cur_event)
	{
		cur_event = smf_get_next_event(smf);
	}

	while(cur_event && cur_event->time_seconds < cur_max_time)
	{
		if(!smf_event_is_metadata(cur_event))
		{
			if( (cur_event->midi_buffer_length == 3) &&
			    ((cur_event->midi_buffer[0] & NOTE_ON) == NOTE_ON) &&
			    (track == -1 || cur_event->track_number == track) &&
			    cur_event->midi_buffer[2] > 0)
			{
				if(evs == nullptr)
				{
					evs = (event_t *)malloc(sizeof(event_t) * 1000);
				}

				int key = cur_event->midi_buffer[1];
				int velocity = cur_event->midi_buffer[2];

				evs[nevs].type = TYPE_ONSET;
				size_t evpos = cur_event->time_seconds * (44100.0 / speed);
				evs[nevs].offset = evpos - pos;

				int i = mmap.lookup(key);
				if(i != -1)
				{
					evs[nevs].instrument = i;
					evs[nevs].velocity = velocity / 127.0;

					++nevs;
					if(nevs > 999)
					{
						fprintf(stderr, "Midi event overflow\n");
						break;
					}
				}
			}
		}

		cur_event = smf_get_next_event(smf);
	}

	if(!cur_event)
	{
		if(loop)
		{
			smf_rewind(smf);
			offset += cur_max_time;
		}
		else
		{
			if(evs == nullptr)
			{
				evs = (event_t *)malloc(sizeof(event_t) * 1000);
			}
			evs[nevs].type = TYPE_STOP;
			evs[nevs].offset = len - 1;
			++nevs;
		}
	}

	*nevents = nevs;

	return evs;
}

void MidiFile::post()
{
}

extern "C" {
	void *create()
	{
		return new MidiFile();
	}

	void destroy(void *h)
	{
		MidiFile *midifile = (MidiFile*)h;
		delete midifile;
	}

	bool init(void *h, int i, char *inames[])
	{
		MidiFile *midifile = (MidiFile*)h;
		return midifile->init(i, inames);
	}

	void setparm(void *h, const char *parm, const char *value)
	{
		MidiFile *midifile = (MidiFile*)h;
		midifile->setParm(parm, value);
	}

	bool start(void *h)
	{
		MidiFile *midifile = (MidiFile*)h;
		return midifile->start();
	}

	void stop(void *h)
	{
		MidiFile *midifile = (MidiFile*)h;
		midifile->stop();
	}

	void pre(void *h)
	{
		MidiFile *midifile = (MidiFile*)h;
		midifile->pre();
	}

	event_t *run(void *h, size_t pos, size_t len, size_t *nev)
	{
		MidiFile *midifile = (MidiFile*)h;
		return midifile->run(pos, len, nev);
	}

	void post(void *h)
	{
		MidiFile *midifile = (MidiFile*)h;
		midifile->post();
	}
}