Module Mad

module Mad: sig .. end

Functions for decoding mp3 files using the libmad.

Author(s): Samuel Mimram

Exceptions

exception Mad_error of string

An error occured with libmad.

exception Read_error of string

An error occured while reading a file.

exception End_of_stream

The end of the mp3 stream was reached.

exception Openfile_error of string

Could not open a file.

exception Closefile_error of string

Could not close a file.

Decoding files

type mad_file

An mp3 file opened for decoding.

val openfile : string -> mad_file

Open an mp3 file.

Raises Openfile_error if an error occured while trying to open the file.

val openstream : (int -> string * int) -> mad_file

openstream read_func opens a stream where read_func n should be a function which returns n bytes of data or less, the second component of the result being the number of bytes to read in the fist component.

val close : mad_file -> unit

Close an mp3 file previously opened with openfile.

Raises Closefile_error if an error occured while trying to close the file.

val get_current_position : mad_file -> int

Get the current position (in bytes) of the decoder in the mp3 file which should have been opened with openfile.

val decode_frame : mad_file -> string

Decode an mp3 frame. Returned data in interleaved when there are two channels, and mono data when there is only one.

val decode_frame_float : mad_file -> float array array

Decode an mp3 frame.

val get_output_format : mad_file -> int * int * int

Get the samplerate, number of channels and samples per channel currently in the synth. This should be called after decode_frame or decode_frame_float.

val duration : string -> float

Compute the duration of a file, in seconds. Never raises any exception, but returns 0. in case of error. The returned duration is exact but its computation is not efficient, as it proceeds by completely decoding the file.