Wav::Write(3)

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 - 1;
        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).
    Kurt George Gjerde <kurt.gjerde@media.uib.no>. (0.02-0.03)