NAME

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

NOTES

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

SEE ALSO

    L<Audio::Wav::Read>

    L<Audio::Wav::Write>

METHODS

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

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

    my $write = $wav -> write( 'testout.wav', $details );
    my $write = Audio::Wav -> write( 'testout.wav', $details);
    my $write = Audio::Wav -> write( 'testout.wav', $details, %options );

    my $read = $wav -> read( 'testin.wav' );
    my $read = Audio::Wav -> read( 'testin.wav' );
    my $read = Audio::Wav -> read( 'testin.wav', %options );

    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 );

COPYRIGHT

    Copyright (c) 2007-2012 Brian Szymanski <brianski@cpan.org>
    Copyright (c) 1998-2006 Nick Peskett <npeskett@cpan.org>
    Copyright (c) 2001 Kurt George Gjerde <KJERDE@cpan.org>

AUTHORS

    Nick Peskett (see http://www.peskett.co.uk/ for contact details).
    Brian Szymanski <ski-cpan@allafrica.com> (0.07-0.14)
    Wolfram humann (pureperl 24 and 32 bit read support in 0.09)
    Kurt George Gjerde <kurt.gjerde@media.uib.no>. (0.02-0.03)

    see also Changes file