// Create a new mpg123 decoder instance
func NewDecoder(decoder string) (*Decoder, error) {
var err C.int
var mh *C.mpg123_handle
if decoder != "" {
mh = C.mpg123_new(nil, &err)
} else {
cdecoder := C.CString(decoder)
defer C.free(unsafe.Pointer(cdecoder))
mh = C.mpg123_new(cdecoder, &err)
}
if mh == nil {
errstring := C.mpg123_plain_strerror(err)
defer C.free(unsafe.Pointer(errstring))
return nil, fmt.Errorf("Error initializing mpg123 decoder: %s", errstring)
}
dec := new(Decoder)
dec.handle = mh
return dec, nil
}
func Open(path string) (*Mp3ReaderSeekerCloser, error) {
var errInt C.int
handle := C.mpg123_new(nil, &errInt)
if err := mpg123Error(errInt); err != nil {
return nil, err
}
cs := C.CString(path)
defer C.free(unsafe.Pointer(cs))
if err := mpg123Error(C.mpg123_open(handle, cs)); err != nil {
return nil, err
}
rsc := &Mp3ReaderSeekerCloser{
handle: handle,
}
runtime.SetFinalizer(rsc, (*Mp3ReaderSeekerCloser).free)
return rsc, nil
}
// NewDecoder returns a new decoder to be used for decoding mp3 audio data
//
// The Close method should be called when finished with the decoder so as to
// not leak resources.
func NewDecoder(r io.Reader) (*Decoder, error) {
var e C.int
mh := C.mpg123_new(nil, &e)
if mh == nil || e != 0 {
return nil, toError(e)
}
err := toError(C.mpg123_open_feed(mh))
if err != nil {
return nil, err
}
C.mpg123_format_none(mh)
C.mpg123_format(mh, 44100, C.MPG123_STEREO, C.MPG123_ENC_FLOAT_32)
buf := make([]byte, ReadBufferSize)
return &Decoder{mh: mh, src: r, buf: buf}, nil
}
func DecodeTrack(file string, control chan int) {
var v1 *C.mpg123_id3v1
var v2 *C.mpg123_id3v2
m := C.mpg123_new(nil, nil)
defer C.mpg123_delete(m)
f := C.CString(file)
if err := C.mpg123_open(m, f); err != C.MPG123_OK {
panic("Error reading file")
}
defer C.mpg123_close(m)
C.mpg123_scan(m)
meta := C.mpg123_meta_check(m)
if meta == C.MPG123_ID3 && C.mpg123_id3(m, &v1, &v2) == C.MPG123_OK {
var title, artist, album, genre string
switch false {
case v2 == nil:
fmt.Println("ID3V2 tag found")
title = C.GoString(v2.title.p)
artist = C.GoString(v2.artist.p)
album = C.GoString(v2.album.p)
genre = C.GoString(v2.genre.p)
case v1 == nil:
fmt.Println("ID3V2 tag found")
title = C.GoString(&v1.title[0])
artist = C.GoString(&v1.artist[0])
album = C.GoString(&v1.album[0])
genre = "Unknown" // FIXME convert int to string
}
fmt.Println(title)
fmt.Println(artist)
fmt.Println(album)
fmt.Println(genre)
}
default_driver := C.ao_default_driver_id()
var format C.ao_sample_format
var device *C.ao_device
var channels, encoding C.int
var rate C.long
C.mpg123_getformat(m, &rate, &channels, &encoding)
format.bits = 16
format.channels = channels
format.rate = C.int(rate)
format.byte_format = C.AO_FMT_LITTLE
device = C.ao_open_live(default_driver, &format, nil)
if device == nil {
panic("Error opening device")
return
}
defer C.ao_close(device)
var ret C.int
var fill C.size_t
buf := make([]C.uchar, 1024*16)
for {
ret = C.mpg123_read(m, (*C.uchar)(unsafe.Pointer(&buf)), 16*1024, &fill)
if ret == C.MPG123_DONE {
control <- 1
break
}
C.ao_play(device, (*C.char)(unsafe.Pointer(&buf)), 16*1024)
}
}