doc.go

// Copyright (c) 2017 Marc René Arns. All rights reserved.
// Use of this source code is governed by a MIT
// license that can be found in the LICENSE file.

/*
Package smfwriter provides a writer of Standard MIDI Files (SMF).

Usage

	import (
		"gitlab.com/gomidi/midi/smf"
		"gitlab.com/gomidi/midi/smf/smfwriter"
		"gitlab.com/gomidi/midi/midimessage/meta"    // (Meta Messages)
		. "gitlab.com/gomidi/midi/midimessage/channel" // (Channel Messages)

		// you may also want to use these
		// gitlab.com/gomidi/midi/midimessage/cc         (ControlChange Messages)
		// gitlab.com/gomidi/midi/midimessage/sysex      (System Exclusive Messages)
	)

	var err error

	tpq := smf.MetricTicks(0) // set the time resolution in ticks per quarter note; 0 uses the defaults (i.e. 960)

	writeMIDI := func (wr smf.Writer) {

		// always set the delta before writing
		wr.SetDelta(tpq.Ticks8th())

		// starts MIDI key 65 on MIDI channel 3 with velocity 90 with delta of 480 to
		// the beginning of the track (note starts after a quaver pause)
		// MIDI channels 1-16 correspond to channel.Channel0 - channel.Channel15.
		err = wr.Write(Channel2.NoteOn(65, 90))

		if err != nil {
			return
		}

		wr.SetDelta(tpq.Ticks4th())

		// stops MIDI note 65 on MIDI channel 3 with delta of 960 to previous message
		// this results in a duration of 1 quarter note for midi note 65
		err = wr.Write(Channel2.NoteOff(65))

		if err != nil {
			return
		}

		// finishes the first track and writes it to the file
		err = wr.Write(meta.EndOfTrack)

		if err != nil {
			return
		}

		// the next write writes to the second track
		// after writing delta is always 0, so we start here at the beginning of the second track
		err = wr.Write(meta.Text("hello second track!"))

		if err != nil {
			return
		}

		// finishes the second track and writes it to the file
		err = wr.Write(meta.EndOfTrack)
	}

	// the number passed to the NumTracks option must match the tracks written
	// if NumTracks is not passed, it defaults to single track (SMF0)
	// if numtracks > 1, SMF1 format is chosen.
	// if TimeFormat is not passed, smf.MetricTicks(960) will be chosen
	smfwriter.WriteFile("file.mid", writeMIDI, smfwriter.NumTracks(2), smfwriter.TimeFormat(tpq))

	// deal with err

*/
package smfwriter