---------------------------------------------------------------------
                 README file for Audio::Wav (0.11).
---------------------------------------------------------------------

Modules for reading & writing Microsoft WAV files.

---------------------------------------------------------------------
                            INSTALLATION
---------------------------------------------------------------------

tar zxvf Audio-Wav-0.06.tar.gz
cd Audio-Wav-0.06
perl Makefile.PL
make test
make install

---------------------------------------------------------------------
                       LICENSE AND COPYRIGHT
---------------------------------------------------------------------

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

Copyright (c) 2010 Brian Szymanski <[email protected]>
Copyright (c) 1999-2001,2004-2006 Nick Peskett (http://www.peskett.co.uk/)
Copyright (c) 2004 Kurt George Gjerde <[email protected]>

---------------------------------------------------------------------
                           DOCUMENTATION
---------------------------------------------------------------------

                             Audio::Wav
         Modules for reading & writing Microsoft WAV files.
---------------------------------------------------------------------

NAME
   Audio::Wav - Modules for reading & writing Microsoft WAV files.

SYNOPSIS
   # copying a file and adding some cue points to the output file
   use Audio::Wav;
   my $wav = new Audio::Wav;
   my $read = $wav -> read( 'input.wav' );
   my $write = $wav -> write( 'output.wav', $read -> details() );
   print "input is ", $read -> length_seconds(), " seconds long\n";

   $write -> set_info( 'software' => 'Audio::Wav' );
   my $data;
   #read 512 bytes
   while ( defined( $data = $read -> read_raw( 512 ) ) ) {
       $write -> write_raw( $data );
   }
   my $length = $read -> length_samples();
   my( $third, $half, $twothirds ) = map int( $length / $_ ), ( 3, 2, 1.5 );
   my %samp_loop = (
       'start' => $third,
       'end'   => $twothirds,
   );
   $write -> add_sampler_loop( %samp_loop );
   $write -> add_cue( $half, "cue label 1", "cue note 1" );
   $write -> finish();

   # splitting a multi-channel file to seperate mono files (slowly!);
   use Audio::Wav;
   my $read = $wav -> read( '4ch.wav' );
   my $details = $read -> details();
   my %out_details = map { $_ => $details -> {$_} } 'bits_sample', 'sample_rate';
   $out_details{'channels'} = 1;
   my @out_files;
   my $in_channels = $details -> {'channels'};
   foreach my $channel ( 1 .. $in_channels ) {
       push @out_files, $wav -> write( 'multi_' . $channel . '.wav', \%out_details );
   }

   while ( 1 ) {
       my @channels = $read -> read();
       last unless @channels;
       foreach my $channel_id ( 0 .. $#channels ) {
           $out_files[$channel_id] -> write( $channels[$channel_id] );
       }
   }

   # not entirely neccessary as finish is done in DESTROY now (if the file hasn't been finished already).
   foreach my $write ( @out_files ) {
       $write -> finish();
   }

NOTES
   All sample positions are now in sample offsets (unless option
   '.01compatible' is true).

   There is now *very* basic support for WAVEFORMATEXTENSIBLE (in fact it
   only recognises that the file is in this format). The key 'wave-ex' is
   used in the detail hash to denote this format when reading or writing.
   I'd like to do more with this, but don't have any hardware or software
   to test these files, also don't really have any spare time to do the
   implementation at present.

   One day I plan to learn enough C to do the sample reading/ writing in
   XS, but for the time being it's done using pack/ unpack in Perl and is
   slow. Working with the raw format doesn't suffer in this way.

   It's likely that reading/ writing files with bit-depth greater than 16
   won't work properly, I need to look at this at some point.

DESCRIPTION
   These modules provide a method of reading & writing uncompressed
   Microsoft WAV files.

METHODS
 new
   Returns a blessed Audio::Wav object. All the parameters are optional and
   default to 0

       my %options = (
           '.01compatible'         => 0,
           'oldcooledithack'       => 0,
           'debug'                 => 0,
       );
       my $wav = Audio::Wav -> new( %options );

 write
   Returns a blessed Audio::Wav::Write object.

       my $details = {
           'bits_sample'   => 16,
           'sample_rate'   => 44100,
           'channels'      => 2,
       };

       my $write = $wav -> write( 'testout.wav', $details );

   See Audio::Wav::Write for methods.

 read
   Returns a blessed Audio::Wav::Read object.

       my $read = $wav -> read( 'testout.wav' );

   See Audio::Wav::Read for methods.

 set_error_handler
   Specifies a subroutine for catching errors. The subroutine should take a
   hash as input. The keys in the hash are 'filename', 'message' (error
   message), and 'warning'. If no error handler is set, die and warn will
   be used.

       sub myErrorHandler {
           my( %parameters ) = @_;
           if ( $parameters{'warning'} ) {
               # This is a non-critical warning
               warn "Warning: $parameters{'filename'}: $parameters{'message'}\n";
           } else {
               # Critical error!
               die "ERROR: $parameters{'filename'}: $parameters{'message'}\n";
           }
       }
       $wav -> set_error_handler( \&myErrorHandler );

---------------------------------------------------------------------
                          Audio::Wav::Read
              Module for reading Microsoft WAV files.
---------------------------------------------------------------------

NAME
   Audio::Wav::Read - Module for reading Microsoft WAV files.

SYNOPSIS
   use Audio::Wav;

   my $wav = new Audio::Wav;
   my $read = $wav -> read( 'filename.wav' );
OR
   my $read = Audio::Wav -> read( 'filename.wav' );

   my $details = $read -> details();

DESCRIPTION
   Reads Microsoft Wav files.

SEE ALSO
   Audio::Wav

   Audio::Wav::Write

NOTES
   This module shouldn't be used directly, a blessed object can be returned
   from Audio::Wav.

METHODS
 file_name
   Returns the file name.

       my $file = $read -> file_name();

 get_info
   Returns information contained within the wav file.

       my $info = $read -> get_info();

   Returns a reference to a hash containing; (for example, a file marked up
   for use in Audio::Mix)

       {
           'keywords'      => 'bpm:126 key:a',
           'name'          => 'Mission Venice',
           'artist'        => 'Nightmares on Wax'
       };

 get_cues
   Returns the cuepoints marked within the wav file.

       my $cues = $read -> get_cues();

   Returns a reference to a hash containing; (for example, a file marked up
   for use in Audio::Mix) (position is sample position)

       {
           1 => {
               label       => 'sig',
               position    => 764343,
               note        => 'first'
           },
           2 => {
               label       => 'fade_in',
               position    => 1661774,
               note        => 'trig'
           },
           3 => {
               label       => 'sig',
               position    => 18033735,
               note        => 'last'
           },
           4 => {
               label       => 'fade_out',
               position    => 17145150,
               note        => 'trig'
           },
           5 => {
               label       => 'end',
               position    => 18271676
           }
       }

 read_raw
   Reads raw packed bytes from the current audio data position in the file.

       my $data = $self -> read_raw( $byte_length );

 read_raw_samples
   Reads raw packed samples from the current audio data position in the
   file.

       my $data = $self -> read_raw_samples( $samples );

 read
   Returns the current audio data position sample across all channels.

       my @channels = $self -> read();

   Returns an array of unpacked samples. Each element is a channel i.e (
   left, right ). The numbers will be in the range;

       where $samp_max = ( 2 ** bits_per_sample ) / 2
       -$samp_max to +$samp_max

 position
   Returns the current audio data position (as byte offset).

       my $byte_offset = $read -> position();

 position_samples
   Returns the current audio data position (in samples).

       my $samples = $read -> position_samples();

 move_to
   Moves the current audio data position to byte offset.

       $read -> move_to( $byte_offset );

 move_to_sample
   Moves the current audio data position to sample offset.

       $read -> move_to_sample( $sample_offset );

 length
   Returns the number of bytes of audio data in the file.

       my $audio_bytes = $read -> length();

 length_samples
   Returns the number of samples of audio data in the file.

       my $audio_samples = $read -> length_samples();

 length_seconds
   Returns the number of seconds of audio data in the file.

       my $audio_seconds = $read -> length_seconds();

 details
   Returns a reference to a hash of lots of details about the file. Too
   many to list here, try it with Data::Dumper.....

       use Data::Dumper;
       my $details = $read -> details();
       print Data::Dumper->Dump([ $details ]);

 reread_length
   Rereads the length of the file in case it is being written to as we are
   reading it.

       my $new_data_length = $read -> reread_length();

---------------------------------------------------------------------
                         Audio::Wav::Write
              Module for writing Microsoft WAV files.
---------------------------------------------------------------------

NAME
   Audio::Wav::Write - Module for writing Microsoft WAV files.

SYNOPSIS
       use Audio::Wav;

       my $wav = new Audio::Wav;

       my $sample_rate = 44100;
       my $bits_sample = 16;

       my $details = {
           'bits_sample'   => $bits_sample,
           'sample_rate'   => $sample_rate,
           'channels'      => 1,
           # if you'd like this module not to use a write cache, uncomment the next line
           #'no_cache'     => 1,

       };

       my $write = $wav -> write( 'testout.wav', $details );

       &add_sine( 200, 1 );

       sub add_sine {
           my $hz = shift;
           my $length = shift;
           my $pi = ( 22 / 7 ) * 2;
           $length *= $sample_rate;
           my $max_no =  ( 2 ** $bits_sample ) / 2;
           for my $pos ( 0 .. $length ) {
               $time = $pos / $sample_rate;
               $time *= $hz;
               my $val = sin $pi * $time;
               my $samp = $val * $max_no;
               $write -> write( $samp );
           }
       }

       $write -> finish();

DESCRIPTION
   Currently only writes to a file.

SEE ALSO
   Audio::Wav

   Audio::Wav::Read

NOTES
   This module shouldn't be used directly, a blessed object can be returned
   from Audio::Wav.

METHODS
 finish
   Finishes off & closes the current wav file.

       $write -> finish();

 add_cue
   Adds a cue point to the wav file. If $sample is undefined then the
   position will be the current position (end of all data written so far).

       # $byte_offset for 01 compatibility mode
       $write -> add_cue( $sample, "label", "note"  );

 set_sampler_info
   All parameters are optional.

       my %info = (
           'midi_pitch_fraction'   => 0,
           'smpte_format'          => 0,
           'smpte_offset'          => 0,
           'product'               => 0,
           'sample_period'         => 0,
           'manufacturer'          => 0,
           'sample_data'           => 0,
           'midi_unity_note'       => 65,
       );
       $write -> set_sampler_info( %info );

 add_sampler_loop
   All parameters are optional except start & end.

       my $length = $read -> length_samples();
       my( $third, $twothirds ) = map int( $length / $_ ), ( 3, 1.5 );
       my %loop = (
           'start'                 => $third,
           'end'                   => $twothirds,
           'fraction'              => 0,
           'type'                  => 0,
       );
       $write -> add_sampler_loop( %loop );

 add_display
 set_info
   Sets information to be contained in the wav file.

       $write -> set_info( 'artist' => 'Nightmares on Wax', 'name' => 'Mission Venice' );

 file_name
   Returns the current filename.

       my $file = $write -> file_name();

 write
   Adds a sample to the current file.

       $write -> write( @sample_channels );

   Each element in @sample_channels should be in the range of;

       where $samp_max = ( 2 ** bits_per_sample ) / 2
       -$samp_max to +$samp_max

 write_raw
   Adds some pre-packed data to the current file.

       $write -> write_raw( $data, $data_length );

   Where;

       $data is the packed data
       $data_length (optional) is the length in bytes of the data

 write_raw_samples
   Adds some pre-packed data to the current file, returns number of samples
   written.

       $write -> write_raw_samples( $data, $data_length );

   Where;

       $data is the packed data
       $data_length (optional) is the length in bytes of the data

---------------------------------------------------------------------
                             AUTHORS
---------------------------------------------------------------------

   Nick Peskett (see http://www.peskett.co.uk/ for contact details).
   Brian Szymanski <[email protected]> (0.07-0.11)
   Wolfram humann (pureperl 24 and 32 bit read support in 0.09)
   Kurt George Gjerde <[email protected]>. (0.02-0.03)

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                               END
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