func (spotify *Spotify) finishInitialisation(webApiAuth bool, pa *portAudio) error {
	if webApiAuth {
		if spotify.client = webapi.Auth(); spotify.client != nil {
			if privateUser, err := spotify.client.CurrentUser(); err == nil {
				if privateUser.ID != spotify.session.LoginUsername() {
					return errors.New("Username doesn't match with web-api authorization")
				}
			} else {
				spotify.client = nil
			}
		}
	}
	// init audio could happen after initPlaylist but this logs to output therefore
	// the screen isn't built properly
	portaudio.Initialize()
	go pa.player()
	defer portaudio.Terminate()

	if err := spotify.initPlaylist(); err != nil {
		return err
	}

	spotify.waitForEvents()
	return nil
}

func main() {
	flag.Parse()

	portaudio.Initialize()
	defer portaudio.Terminate()

	portmidi.Initialize()
	defer portmidi.Terminate()

	if *doDemo {
		if err := demo(); err != nil {
			log.Println(err)
		}
		return
	}

	http.Handle("/", http.FileServer(http.Dir("static")))
	http.HandleFunc("/socket", socket.Handler)

	l, err := net.Listen("tcp", *listenAddr)
	if err != nil {
		log.Fatal(err)
	}
	go http.Serve(l, nil)

	u := fmt.Sprintf("http://%v/", *listenAddr)
	if !*doBrowser || !openBrowser(u) {
		fmt.Printf("Open your web browser to %v\n\n", u)
	}

	fmt.Println("Press enter to quit...")
	os.Stdin.Read([]byte{0})
}

func main() {
	w := &window{voices: map[int]*sineVoice{}}
	p := audio.Params{SampleRate: 96000}
	audio.Init(w, p)

	portaudio.Initialize()
	defer portaudio.Terminate()
	s, err := portaudio.OpenDefaultStream(0, 1, p.SampleRate, 64, w.processAudio)
	if err != nil {
		fmt.Println(err)
		return
	}
	if err := s.Start(); err != nil {
		fmt.Println(err)
		return
	}
	defer s.Stop()

	if err := gui.Run(func() {
		gui.NewWindow(w, "beep", func(win *gui.Window) {
			w.Window = win
			gui.SetKeyFocus(w)
		})
	}); err != nil {
		fmt.Println(err)
	}
}

func main() {
	portaudio.Initialize()
	defer portaudio.Terminate()
	hs, err := portaudio.HostApis()
	chk(err)
	err = tmpl.Execute(os.Stdout, hs)
	chk(err)
}

func main() {
	portaudio.Initialize()
	defer portaudio.Terminate()
	e := newEcho(time.Second / 3)
	defer e.Close()
	chk(e.Start())
	time.Sleep(4 * time.Second)
	chk(e.Stop())
}

func main() {
	portaudio.Initialize()
	defer portaudio.Terminate()
	s := newStereoSine(256, 320, sampleRate)
	defer s.Close()
	chk(s.Start())
	time.Sleep(2 * time.Second)
	chk(s.Stop())
}

// Slightly modified exact copy of the portaudio example
func record(f *os.File, timer <-chan time.Time) {
	// form chunk
	_, _ = f.WriteString("FORM")
	binary.Write(f, binary.BigEndian, int32(0))
	_, _ = f.WriteString("AIFF")

	// common chunk
	_, _ = f.WriteString("COMM")
	binary.Write(f, binary.BigEndian, int32(18))
	binary.Write(f, binary.BigEndian, int16(1))
	binary.Write(f, binary.BigEndian, int32(0))
	binary.Write(f, binary.BigEndian, int16(32))
	_, _ = f.Write([]byte{0x40, 0x0e, 0xac, 0x44, 0, 0, 0, 0, 0, 0}) //80-bit sample rate 44100

	// sound chunk
	_, _ = f.WriteString("SSND")
	binary.Write(f, binary.BigEndian, int32(0))
	binary.Write(f, binary.BigEndian, int32(0))
	binary.Write(f, binary.BigEndian, int32(0))
	nSamples := 0
	defer func() {
		// fill in missing sizes
		totalBytes := 4 + 8 + 18 + 8 + 8 + 4*nSamples
		_, _ = f.Seek(4, 0)
		binary.Write(f, binary.BigEndian, int32(totalBytes))
		_, _ = f.Seek(22, 0)
		binary.Write(f, binary.BigEndian, int32(nSamples))
		_, _ = f.Seek(42, 0)
		binary.Write(f, binary.BigEndian, int32(4*nSamples+8))
		f.Close()
	}()

	portaudio.Initialize()
	defer portaudio.Terminate()
	in := make([]int32, 64)
	stream, _ := portaudio.OpenDefaultStream(1, 0, 44100, len(in), in)
	defer stream.Close()

	stream.Start()
	defer stream.Stop()

	for {
		stream.Read()
		binary.Write(f, binary.BigEndian, in)
		nSamples += len(in)
		select {
		case <-timer:
			return
		default:
		}
	}
}

func (spotify *Spotify) finishInitialisation(pa *portAudio) error {
	// init audio could happen after initPlaylist but this logs to output therefore
	// the screen isn't built properly
	portaudio.Initialize()
	go pa.player()
	defer portaudio.Terminate()

	if err := spotify.initPlaylist(); err != nil {
		return err
	}

	spotify.waitForEvents()
	return nil
}

func (a *app) OnInit() {
	var err error
	a.r, err = os.Open(*in)
	if err != nil {
		log.Fatalf("Unable to open file '%s': %s", *in, err)
	}
	var wm webm.WebM
	a.reader, err = webm.Parse(a.r, &wm)
	if err != nil {
		log.Fatal("Unable to parse file: ", err)
	}
	a.duration = wm.GetDuration()
	var vtrack *webm.TrackEntry
	if !*justaudio {
		vtrack = wm.FindFirstVideoTrack()
	}
	var vstream *webm.Stream
	if vtrack != nil {
		vstream = webm.NewStream(vtrack)
		a.fduration = vtrack.GetDefaultDuration()
		a.vchan = vstream.VideoChannel()
	}
	var atrack *webm.TrackEntry
	if !*justvideo {
		atrack = wm.FindFirstAudioTrack()
	}
	var astream *webm.Stream
	if atrack != nil {
		astream = webm.NewStream(atrack)
	}
	splitter := webm.NewSplitter(a.reader.Chan)
	splitter.Split(astream, vstream)

	a.steps = uint(0xffffffff)
	if a.vchan != nil {
		a.img = <-a.vchan
		a.pimg = a.img
	}

	if atrack != nil {
		channels := int(atrack.Audio.Channels)
		a.aw = &AudioWriter{ch: astream.AudioChannel(),
			channels: channels, active: true}
		chk(portaudio.Initialize())
		a.pastream, err = portaudio.OpenDefaultStream(0, channels,
			atrack.Audio.SamplingFrequency, 0, a.aw.processAudio)
		chk(err)
		chk(a.pastream.Start())
	}
}

func main() {
	portaudio.Initialize()
	defer portaudio.Terminate()
	h, err := portaudio.DefaultHostApi()
	chk(err)
	stream, err := portaudio.OpenStream(portaudio.HighLatencyParameters(nil, h.DefaultOutputDevice), func(out []int32) {
		for i := range out {
			out[i] = int32(rand.Uint32())
		}
	})
	chk(err)
	defer stream.Close()
	chk(stream.Start())
	time.Sleep(time.Second)
	chk(stream.Stop())
}

func main() {
	flag.Parse()
	if *random {
		*seed = time.Now().UnixNano()
		fmt.Println("seed =", *seed)
	}
	if *seed != math.MinInt64 {
		*random = true
	}
	rand.Seed(*seed)

	portaudio.Initialize()
	defer portaudio.Terminate()

	p := audio.Params{SampleRate: 48000}

	m := audio.MultiVoice{}
	audio.Init(&m, p)
	// for _, x := range [][2]float64{{1, 1}, {2, 1}, {3, 1}, {4, 1}, {5, 1}, {3, 2}, {4, 3}, {5, 4}, {7, 4}, {6, 5}, {7, 5}, {8, 5}, {9, 5}} {
	for xy := 1; xy <= 60; xy++ {
		for x := 2; x <= int(math.Sqrt(float64(xy))); x++ {
			if y := xy / x; x*y == xy && relPrime(x, y) {
				x, y, xy := float64(x), float64(y), float64(xy)
				c := math.Exp(-xy * math.Log2(y/x) / 12)
				f := y / x
				phase := 0.0
				if *random {
					phase = rand.Float64()
				}
				m.Add(newSineBeat(.5*c, 128*f, 1/xy, phase, .1/f))
			}
		}
	}

	s, err := portaudio.OpenDefaultStream(0, 1, p.SampleRate, 512, func(out []float32) {
		for i := range out {
			out[i] = float32(audio.Saturate(m.Sing()))
		}
	})
	if err != nil {
		panic(err)
	}
	s.Start()
	fmt.Println("Press Enter to stop.")
	fmt.Scanln()
	s.Stop()
}

func (self *Server) Start() error {
	portaudio.Initialize()
	defer portaudio.Terminate()

	var err error

	if err = self.startAudio(); err != nil {
		return err
	}

	if err = self.startSerial(); err != nil {
		return err
	}

	if err = self.startHttp(); err != nil {
		return err
	}

	return nil
}

func init() {
	portaudio.Initialize()
	go func() {
		defer os.Exit(0)
		sig := make(chan os.Signal, 1)
		signal.Notify(sig)
		if <-sig == syscall.SIGQUIT {
			buf := make([]byte, 1<<10)
			for runtime.Stack(buf, true) == len(buf) {
				buf = make([]byte, 2*len(buf))
			}
			fmt.Fprintln(os.Stderr, string(buf))
		}
		for _, c := range playControls {
			c.Stop()
			<-c.Done
		}
		portaudio.Terminate()
	}()
}

func Run(paths []string) {
	// initialize audio
	portaudio.Initialize()
	defer portaudio.Terminate()

	audio := NewAudio()
	if err := audio.Start(); err != nil {
		log.Fatalln(err)
	}
	defer audio.Stop()

	// initialize glfw
	if err := glfw.Init(); err != nil {
		log.Fatalln(err)
	}
	defer glfw.Terminate()

	// create window
	glfw.WindowHint(glfw.ContextVersionMajor, 2)
	glfw.WindowHint(glfw.ContextVersionMinor, 1)
	window, err := glfw.CreateWindow(width*scale, height*scale, title, nil, nil)
	if err != nil {
		log.Fatalln(err)
	}
	window.MakeContextCurrent()

	// initialize gl
	if err := gl.Init(); err != nil {
		log.Fatalln(err)
	}
	gl.Enable(gl.TEXTURE_2D)

	// run director
	director := NewDirector(window, audio)
	director.Start(paths)
}

func main() {
	if len(os.Args) < 2 {
		fmt.Println("missing required argument:  output file name")
		return
	}
	fmt.Println("Recording.  Press Ctrl-C to stop.")

	sig := make(chan os.Signal, 1)
	signal.Notify(sig, os.Interrupt, os.Kill)

	fileName := os.Args[1]
	if !strings.HasSuffix(fileName, ".aiff") {
		fileName += ".aiff"
	}
	f, err := os.Create(fileName)
	chk(err)

	// form chunk
	_, err = f.WriteString("FORM")
	chk(err)
	chk(binary.Write(f, binary.BigEndian, int32(0))) //total bytes
	_, err = f.WriteString("AIFF")
	chk(err)

	// common chunk
	_, err = f.WriteString("COMM")
	chk(err)
	chk(binary.Write(f, binary.BigEndian, int32(18)))                  //size
	chk(binary.Write(f, binary.BigEndian, int16(1)))                   //channels
	chk(binary.Write(f, binary.BigEndian, int32(0)))                   //number of samples
	chk(binary.Write(f, binary.BigEndian, int16(32)))                  //bits per sample
	_, err = f.Write([]byte{0x40, 0x0e, 0xac, 0x44, 0, 0, 0, 0, 0, 0}) //80-bit sample rate 44100
	chk(err)

	// sound chunk
	_, err = f.WriteString("SSND")
	chk(err)
	chk(binary.Write(f, binary.BigEndian, int32(0))) //size
	chk(binary.Write(f, binary.BigEndian, int32(0))) //offset
	chk(binary.Write(f, binary.BigEndian, int32(0))) //block
	nSamples := 0
	defer func() {
		// fill in missing sizes
		totalBytes := 4 + 8 + 18 + 8 + 8 + 4*nSamples
		_, err = f.Seek(4, 0)
		chk(err)
		chk(binary.Write(f, binary.BigEndian, int32(totalBytes)))
		_, err = f.Seek(22, 0)
		chk(err)
		chk(binary.Write(f, binary.BigEndian, int32(nSamples)))
		_, err = f.Seek(42, 0)
		chk(err)
		chk(binary.Write(f, binary.BigEndian, int32(4*nSamples+8)))
		chk(f.Close())
	}()

	portaudio.Initialize()
	defer portaudio.Terminate()
	in := make([]int32, 64)
	stream, err := portaudio.OpenDefaultStream(1, 0, 44100, len(in), in)
	chk(err)
	defer stream.Close()

	chk(stream.Start())
	for {
		chk(stream.Read())
		chk(binary.Write(f, binary.BigEndian, in))
		nSamples += len(in)
		select {
		case <-sig:
			return
		default:
		}
	}
	chk(stream.Stop())
}

func main() {
	if len(os.Args) < 2 {
		fmt.Println("missing required argument:  input file name")
		return
	}
	fmt.Println("Playing.  Press Ctrl-C to stop.")

	sig := make(chan os.Signal, 1)
	signal.Notify(sig, os.Interrupt, os.Kill)

	fileName := os.Args[1]
	f, err := os.Open(fileName)
	chk(err)
	defer f.Close()

	id, data, err := readChunk(f)
	chk(err)
	if id.String() != "FORM" {
		fmt.Println("bad file format")
		return
	}
	_, err = data.Read(id[:])
	chk(err)
	if id.String() != "AIFF" {
		fmt.Println("bad file format")
		return
	}
	var c commonChunk
	var audio io.Reader
	for {
		id, chunk, err := readChunk(data)
		if err == io.EOF {
			break
		}
		chk(err)
		switch id.String() {
		case "COMM":
			chk(binary.Read(chunk, binary.BigEndian, &c))
		case "SSND":
			chunk.Seek(8, 1) //ignore offset and block
			audio = chunk
		default:
			fmt.Printf("ignoring unknown chunk '%s'\n", id)
		}
	}

	//assume 44100 sample rate, mono, 32 bit

	portaudio.Initialize()
	defer portaudio.Terminate()
	out := make([]int32, 8192)
	stream, err := portaudio.OpenDefaultStream(0, 1, 44100, len(out), &out)
	chk(err)
	defer stream.Close()

	chk(stream.Start())
	defer stream.Stop()
	for remaining := int(c.NumSamples); remaining > 0; remaining -= len(out) {
		if len(out) > remaining {
			out = out[:remaining]
		}
		err := binary.Read(audio, binary.BigEndian, out)
		if err == io.EOF {
			break
		}
		chk(err)
		chk(stream.Write())
		select {
		case <-sig:
			return
		default:
		}
	}
}

func main() {
	if len(os.Args) < 2 {
		fmt.Println("Usage:", os.Args[0], "hostname:port [buffer-duration]")
		os.Exit(1)
		return
	}

	portaudio.Initialize()
	defer portaudio.Terminate()

	addr := os.Args[1]
	bufferStr := "100ms"
	if len(os.Args) > 2 {
		bufferStr = os.Args[2]
	}
	bufferLen, err := time.ParseDuration(bufferStr)
	if err != nil {
		fmt.Printf("Invalid buffer length: %v\n", err)
		return
	}

	conn, err := net.Dial("tcp", addr)
	if err != nil {
		fmt.Println("Error connecting to server:", err)
		return
	}
	defer conn.Close()

	buf := make([]byte, 8)
	_, err = io.ReadFull(conn, buf)
	if err != nil {
		fmt.Println("Error reading headers:", err)
		return
	}

	if buf[0] != 'R' {
		fmt.Printf("Invalid header start: %x\n", buf[0])
		return
	} else if buf[1] == 0 {
		fmt.Println("Server is full")
		return
	} else if buf[1] != 1 {
		fmt.Printf("Unsupported protocol version: %d\n", buf[1])
		return
	}

	flags := buf[2]
	if flags&rawstreamer.EncodingLittleEndian != 0 {
		Endianness = binary.LittleEndian
	} else if flags&rawstreamer.EncodingBigEndian != 0 {
		Endianness = binary.BigEndian
	} else {
		fmt.Println("Encoding endianness not specified!")
		return
	}

	encoding := flags & rawstreamer.EncodingMask

	numBytes := int(buf[3])
	bits := numBytes * 8
	if numBytes < 1 || numBytes > 4 {
		fmt.Printf("Unsupported number of bits: %d\n", bits)
		return
	}
	if encoding == rawstreamer.EncodingFloatingPoint {
		numBytes = 4
		bits = 32
	}

	sampleRate := Endianness.Uint32(buf[4:])
	fmt.Printf("Streaming info: %dHz, ", sampleRate)
	fmt.Printf("%dbit %s, ", bits, rawstreamer.EncodingString[encoding])
	fmt.Printf("%s, %v buffer\n", Endianness.String(), bufferLen)

	bufferSize := sampleRate / 50 // 20ms buffer size

	Buffers = []chan float32{
		make(chan float32, getChannelBufferSize(bufferLen, bufferSize, sampleRate)),
		make(chan float32, getChannelBufferSize(bufferLen, bufferSize, sampleRate)),
	}

	Buffering = int32(getChannelBufferSize(bufferLen, bufferSize, sampleRate))
	LastLeft = 0
	LastRight = 0

	printStatus()

	Stream, err = portaudio.OpenDefaultStream(0, 2, float64(sampleRate), int(bufferSize), processAudio)
	defer Stream.Close()
	err = Stream.Start()
	if err != nil {
		fmt.Println("Failed to start stream:", err)
		return
	}
	defer func() {
		Stream.Stop()
		close(Buffers[0])
		close(Buffers[1])
	}()

//.........这里部分代码省略.........

// Init starts the audio system, loads sound assets, and starts the sound loop.
func Init() error {
	if err := portaudio.Initialize(); err != nil {
		return err
	}

	log.Printf("PortAudio version: %d %s", portaudio.Version(), portaudio.VersionText())

	var err error
	makeBuffer := func(name string) []int16 {
		if err != nil {
			return nil
		}

		var r io.Reader
		if r, err = asset.Reader(name); err != nil {
			return nil
		}

		var w *wav
		if w, err = decodeWAV(r); err != nil {
			return nil
		}

		log.Printf("%s: %+v", name, w)
		buf := make([]int16, len(w.data)/2)
		for i := 0; i < len(buf); i++ {
			buf[i] = int16(w.data[i*2])
			buf[i] += int16(w.data[i*2+1]) << 8
		}
		return buf
	}

	var soundBuffers [][]int16
	for _, a := range soundAssets {
		soundBuffers = append(soundBuffers, makeBuffer(a))
	}
	if err != nil {
		return err
	}

	soundQueue := make(chan Sound, soundQueueSize)
	Play = func(s Sound) {
		soundQueue <- s
	}

	done := make(chan bool)
	Terminate = func() {
		done <- true
		<-done
		close(done)
		logFatalIfErr("portaudio.Terminate", portaudio.Terminate())
	}

	go func() {
		const (
			numInputChannels  = 0     /* zero input - no recording */
			numOutputChannels = 2     /* stereo output */
			sampleRate        = 44100 /* samples per second */
			intervalMs        = 100
			framesPerBuffer   = sampleRate / 1000.0 * intervalMs /*  len(buf) == numChannels * framesPerBuffer */
			outputBufferSize  = numOutputChannels * framesPerBuffer
		)

		// Temporary buffers to read and write the next audio batch.
		tmpIn := make([]int16, outputBufferSize)
		tmpOut := make([]int16, outputBufferSize)

		// outputRingBuffer is a buffer that the PortAudio callback will read data from,
		// and that we will periodically wake up to write new data to.
		outputRingBuffer := newRingBuffer(outputBufferSize * 10)

		// process is the callback that PortAudio will call when it needs audio data.
		process := func(out []int16) {
			outputRingBuffer.pop(tmpIn)
			for i := 0; i < len(out); i++ {
				out[i] = tmpIn[i]
			}
		}

		stream, err := portaudio.OpenDefaultStream(numInputChannels, numOutputChannels, sampleRate, framesPerBuffer, process)
		logFatalIfErr("portaudio.OpenDefaultStream", err)
		defer func() {
			logFatalIfErr("stream.Close", stream.Close())
		}()

		logFatalIfErr("stream.Start()", stream.Start())
		defer func() {
			// stream.Stop blocks until all samples have been played.
			logFatalIfErr("stream.Stop", stream.Stop())
			done <- true
		}()

		var active [][]int16
		quit := false

	loop:
		for {
			select {
			case <-time.After(intervalMs * time.Millisecond):
//.........这里部分代码省略.........

func init() {
	portaudio.Initialize()
}

func Run() {
	chk(LoadUgen("./inst/spread.so", "spread"))
	chk(LoadUgen("./inst/reverb.so", "reverb"))
	chk(LoadUgen("./inst/lead2.so", "midi"))
	chk(LoadUgen("./inst/lead.so", "lead"))
	chk(LoadUgen("./inst/bass.so", "bass"))
	chk(LoadUgen("./inst/snare.so", "snare"))
	chk(LoadUgen("./inst/lopass.so", "lopass"))

	shouldRecord := flag.Bool("record", false, "whether to record")
	addr := flag.String("addr", "localhost:8080", "http service address")
	flag.Parse()

	portaudio.Initialize()
	defer portaudio.Terminate()

	if *shouldRecord {
		var err error
		f, err = os.Create("/tmp/recording.f32")
		// # to play:
		// $ play -x -r 44100 -c 1 /tmp/recording.f32
		// # to convert to wav:
		// $ sox -x -r 44100 -c 1 /tmp/recording.f32 recording.wav

		chk(err)
	}

	s, err := openStream(processAudio)
	fmt.Println("%+v\n", s.Info())
	chk(err)
	defer s.Close()

	if true {
		service.Initialize(*addr, cmdHandle)
	}

	if true {
		client, err := coremidi.NewClient("midi client")
		chk(err)
		port, err := coremidi.NewInputPort(client, "test",
			func(source coremidi.Source, event []byte) {
				handleMidiEvent(event, bleeps)
			})
		chk(err)
		sources, err := coremidi.AllSources()
		chk(err)
		for _, source := range sources {
			//			func(source coremidi.Source) {
			fmt.Printf("Listening to midi source %s [%s]\n", source.Name(), source.Manufacturer())
			port.Connect(source)
			//		}(source)
		}
	}

	filterOn("reverb", 80.0, []*float64{getBus(0)})
	filterOn("lopass", 90.0, []*float64{getBus(0), &resFreq, &Q})
	filterOn("spread", 100.0, []*float64{getBus(0), getBus(1)})

	go func() {
		for {
			fmt.Printf("inner loop taking avg ~%f samples\n", inner.Seconds()*sampleRate/float64(innerCount))
			inner = 0
			innerCount = 0
			time.Sleep(1 * time.Second)
		}
	}()

	chk(s.Start())
	select {}
	defer chk(s.Stop())
}