// Open reads the vorbis headers from an ogg.Reader and performs the setup needed to decode the data.
func OpenOgg(in *ogg.Reader) (*Vorbis, error) {
v := new(Vorbis)
v.reader = in
r, err := ogg.NewBitReaderErr(v.reader.NextPacket())
if err != nil {
return nil, err
}
err = v.header.ReadFrom(r)
if err != nil {
return nil, err
}
b, err := v.reader.NextPacket()
if err != nil {
return nil, err
}
v.comments.ReadFrom(b)
r, err = ogg.NewBitReaderErr(v.reader.NextPacket())
if err != nil {
return nil, err
}
v.setup.init(&v.header)
err = v.setup.ReadFrom(r)
if err != nil {
return nil, err
}
return v, nil
}
// DecodePacket decodes a packet from the input.
// The result is a two-dimensional array, the first index corresponds to the channel, the second to the sample position.
// The number of samples decoded can vary, but will never exceed MaxBlockSize()
func (v *Vorbis) DecodePacket() ([][]float32, error) {
var out [][]float32
if v.overlap == nil {
r, err := ogg.NewBitReaderErr(v.reader.NextPacket())
if err != nil {
return nil, err
}
out, v.overlap, err = v.setup.decodePacket(r, nil)
v.position += uint64(len(out[0]))
}
r, err := ogg.NewBitReaderErr(v.reader.NextPacket())
if err != nil {
return nil, err
}
out, v.overlap, err = v.setup.decodePacket(r, v.overlap)
v.position += uint64(len(out[0]))
return out, err
}