func newEcho(delay time.Duration) *echo {
h, err := portaudio.DefaultHostApi()
chk(err)
p := portaudio.LowLatencyParameters(h.DefaultInputDevice, h.DefaultOutputDevice)
p.Input.Channels = 1
p.Output.Channels = 1
e := &echo{buffer: make([]float32, int(p.SampleRate*delay.Seconds()))}
e.Stream, err = portaudio.OpenStream(p, e.processAudio)
chk(err)
return e
}
func (a *Audio) Start() error {
host, err := portaudio.DefaultHostApi()
if err != nil {
return err
}
parameters := portaudio.HighLatencyParameters(nil, host.DefaultOutputDevice)
stream, err := portaudio.OpenStream(parameters, a.Callback)
if err != nil {
return err
}
if err := stream.Start(); err != nil {
return err
}
a.stream = stream
return nil
}
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())
}