jacquesv2.go

package main

import (
	"fmt"
	synth "github.com/DylanMeeus/GoAudio/synthesizer"
	"github.com/DylanMeeus/GoAudio/wave"
)

const (
	sr           = 44100.
	noteDuration = 0.5
)

func main() {
	st, err := synth.NewTriangleTable(8*1024, 11)
	if err != nil {
		panic(err)
	}
	osc, err := synth.NewLookupOscillator(sr, st, 0)
	if err != nil {
		panic(err)
	}

	waitdur := .1
	cdecdur := 0.6
	efgdur := 0.6
	gagfecdur := 0.5
	cgcdur := 0.5

	// notes: https://www.true-piano-lessons.com/frere-jacques.html

	output := []wave.Frame{}
	// frere jacues
	output = append(output, play(osc, "C5", cdecdur)...)
	output = append(output, play(osc, "D5", cdecdur)...)
	output = append(output, play(osc, "E5", cdecdur)...)
	output = append(output, play(osc, "C5", cdecdur)...)
	output = append(output, play(osc, "C5", cdecdur)...)
	output = append(output, play(osc, "D5", cdecdur)...)
	output = append(output, play(osc, "E5", cdecdur)...)
	output = append(output, play(osc, "C5", cdecdur)...)
	output = append(output, play(osc, "WAIT", waitdur)...)
	// dormez-vous
	output = append(output, play(osc, "E5", efgdur)...)
	output = append(output, play(osc, "F5", efgdur)...)
	output = append(output, play(osc, "G5", efgdur)...)
	output = append(output, play(osc, "WAIT", 0.2)...)
	output = append(output, play(osc, "E5", efgdur)...)
	output = append(output, play(osc, "F5", efgdur)...)
	output = append(output, play(osc, "G5", efgdur)...)
	// sonnez les matines
	output = append(output, play(osc, "G5", gagfecdur)...)
	output = append(output, play(osc, "A5", gagfecdur)...)
	output = append(output, play(osc, "G5", gagfecdur)...)
	output = append(output, play(osc, "F5", gagfecdur)...)
	output = append(output, play(osc, "E5", gagfecdur)...)
	output = append(output, play(osc, "C5", gagfecdur)...)
	output = append(output, play(osc, "WAIT", 0.2)...)
	output = append(output, play(osc, "G5", gagfecdur)...)
	output = append(output, play(osc, "A5", gagfecdur)...)
	output = append(output, play(osc, "G5", gagfecdur)...)
	output = append(output, play(osc, "F5", gagfecdur)...)
	output = append(output, play(osc, "E5", gagfecdur)...)
	output = append(output, play(osc, "C5", gagfecdur)...)
	output = append(output, play(osc, "WAIT", gagfecdur)...)
	// dindindon
	output = append(output, play(osc, "C5", cgcdur)...)
	output = append(output, play(osc, "G5", cgcdur)...)
	output = append(output, play(osc, "C5", cgcdur)...)
	output = append(output, play(osc, "WAIT", 0.1)...)
	output = append(output, play(osc, "C5", cgcdur)...)
	output = append(output, play(osc, "G5", cgcdur)...)
	output = append(output, play(osc, "C5", cgcdur)...)

	wfmt := wave.NewWaveFmt(1, 1, sr, 16, nil)
	wave.WriteFrames(output, wfmt, "frerejacques.wav")
	fmt.Println("done")
}

func play(l *synth.LookupOscillator, note string, duration float64) []wave.Frame {
	var freq float64
	var err error
	if note != "WAIT" {
		freq, err = synth.ParseNoteToFrequency(note)
		if err != nil {
			panic(err)
		}
	} else {
		freq = 0
	}

	frames := make([]wave.Frame, int(duration*sr))
	var adsrtime int
	for i := range frames {
		value := synth.ADSR(0.8, duration, 0.2, 0.1, 0.5, duration-0.05, sr, adsrtime)
		adsrtime++
		frames[i] = wave.Frame(value * l.InterpolateTick(freq))
	}

	return frames
}