example.go

package main

import (
	"fmt"
	"github.com/faiface/beep/effects"
	"log"
	"os"
	"time"

	"github.com/faiface/beep"
	"github.com/faiface/beep/mp3"
	"github.com/faiface/beep/speaker"
)

var mainCtrl *beep.Ctrl
var s beep.StreamSeekCloser
var volume = &effects.Volume{
	Base: 2,
}
var songPos int
var songLen int

func main() {
	tracks := []string{
		//"./ukulele.mp3",
		"./bg.mp3",
		"./classic.mp3",
	}
	i := 0
	f, err := os.Open("./bg.mp3")
	if err != nil {
		log.Fatal(err)
	}
	_, format, err := mp3.Decode(f)
	if err != nil {
		log.Fatal(err)
	}
	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))

	next := make(chan bool)
	go func() {
		for {
			select {
			case <-next:
				fmt.Println(mainCtrl)
				songLen = play(tracks[i])
				i += 1
				fmt.Println(songLen)
			case <-time.After(time.Second):
				fmt.Println(time.Second)
				songPos += 1
				if songPos > songLen && mainCtrl != nil {
					fmt.Println(mainCtrl)
					fmt.Println("end track")
					songPos = 0
					i += 1
					songLen = play(tracks[i])
				}
			}
		}
	}()
	for {
		fmt.Print("Press [ENTER] to next. ")
		fmt.Scanln()
		next <- true
	}
}

func play(path string) int{
	f, err := os.Open(path)
	if err != nil {
		log.Fatal(err)
	}

	s, format, err := mp3.Decode(f)
	if err != nil {
		log.Fatal(err)
	}
	volume.Streamer = s

	mainCtrl = &beep.Ctrl{Streamer: volume}
	speaker.Play(mainCtrl)
	return int(float32(s.Len()) / float32(format.SampleRate))
}