class type t =object..end
method channels : intNumber of channels.
method sample_rate : intSample rate in samples per second.
method duration : intDuration in samples.
method duration_time : floatDuration in seconds.
method seek : int -> unitSeek to a given sample.
method close : unitClose the file. This method should only be called once. The members of the object should not be accessed anymore after this method has been called.
method read : Audio.buffer -> int -> int -> int