NAME
   Audio::Extract::PCM - Extract PCM data from audio files

VERSION
   Version 0.04

SYNOPSIS
   This module's purpose is to extract PCM data from various audio formats.
   PCM is the format in which you send data to your sound card driver. This
   module aims to provide a single interface for PCM extraction from
   various audio formats, compressed and otherwise.

   Currently the implementation makes use of the external "sox" program. As
   of 2008, sox's supported input formats include "wav", "mp3",
   "ogg/vorbis", "flac", if you have compiled sox with support for them,
   but do not include "wma" or "aac".

   I have chosen the use of "sox" for the first implementation of this
   module because it already has an abstract interface to many formats.
   However I plan to include more implementations to (1) maybe include more
   formats, (2) make the implementation more perlish and (3) make the
   module more portable. CPAN has specialized modules like Audio::Mad and
   Ogg::Vorbis::Decoder, to which I could implement an abstract interface.

   If you have suggestions how to include more implementations, or if you
   simply need them and want to motivate me, please contact me.

   Usage example:

       use Audio::PCM::Extract;
       my $extractor = Audio::PCM::Extract->new('song.ogg');
       my $pcm = $extractor->pcm(44100, 2, 2) or die $extractor->error;

METHODS
 new
   Parameters: "filename"

   Constructs a new object to access the specified file.

 pcm
   Parameters: "frequency", "samplesize", "channels"

   Extracts PCM data.

   The sample size is specified in bytes, so 2 means 16 bit sound.

   Returns the pcm data as a reference to a string, or an empty list in
   case of an error (cf. "error").

 error
   Returns the last error that occured for this object.

SEE ALSO
   *       Audio::Mad - Module to decode MPEG files, in particular MP3

   *       Ogg::Vorbis::Decoder - Module to decode Vorbis files

   *       <http://en.wikipedia.org/wiki/Pulse-code_modulation> - PCM
           (Pulse-code modulation)

   *       <http://sox.sourceforge.net/> - SoX homepage

AUTHOR
   Christoph Bussenius, "<pepe at cpan.org>"

   Please include the name of this module in the subject of your emails so
   they won't get lost in spam.

   If you find this module useful, I'll be glad if you drop me a note.

COPYRIGHT & LICENSE
   Copyright 2008 Christoph Bussenius, all rights reserved.

   This program is free software; you can redistribute it and/or modify it
   under the same terms as Perl itself.