func PlayPath(p string, vis Visualizer) error {
var song codec.Song
songs, _, err := codec.ByExtension(p, fileReader(p))
if err != nil {
return err
}
for _, song = range songs {
// Get first song
break
}
sampleRate, channels, err := song.Init()
if err != nil {
return err
}
defer song.Close()
seekRate := int(sampleRate / 10.0) // fps
vis.SetFreq(float64(seekRate))
out, err := output.Get(sampleRate, channels)
if err != nil {
return err
}
out.Start()
for {
samples, err := song.Play(seekRate)
if err != nil {
return err
}
out.Push(samples)
vis.Push(samples)
if len(samples) < seekRate {
// Done
break
}
}
return nil
}
func (srv *Server) audio() {
var out output.Output
var t chan interface{}
var seek *Seek
var dur time.Duration
var err error
send := func(v interface{}) {
go func() {
srv.ch <- v
}()
}
setTime := func() {
send(cmdSetTime(seek.Pos()))
}
tick := func() {
const expected = 4096
if seek == nil {
return
}
next, err := seek.Read(expected)
if len(next) > 0 {
out.Push(next)
setTime()
}
if err != nil {
seek = nil
}
if err == io.ErrUnexpectedEOF {
send(cmdRestartSong)
} else if err != nil {
send(cmdNext)
}
}
doSeek := func(c cmdSeek) {
if seek == nil {
return
}
err := seek.Seek(time.Duration(c))
if err != nil {
send(cmdError(err))
return
}
setTime()
}
setParams := func(c audioSetParams) {
out, err = output.Get(c.sr, c.ch)
if err != nil {
c.err <- fmt.Errorf("mog: could not open audio (%v, %v): %v", c.sr, c.ch, err)
return
}
dur = time.Second / (time.Duration(c.sr * c.ch))
seek = NewSeek(c.dur > 0, dur, c.play)
t = make(chan interface{})
close(t)
c.err <- nil
}
for {
select {
case <-t:
tick()
case c := <-srv.audioch:
log.Printf("%T\n", c)
switch c := c.(type) {
case audioStop:
t = nil
case audioPlay:
t = make(chan interface{})
close(t)
case audioSetParams:
setParams(c)
case cmdSeek:
doSeek(c)
default:
panic("unknown type")
}
}
}
}