NAME

MIDI::Ngram - Find the top repeated note phrases of MIDI files

VERSION

version 0.1300

SYNOPSIS

  use MIDI::Ngram;

  # Analyze a tune and build a new MIDI file of repetitions
  my $mng = MIDI::Ngram->new(
    in_file      => [ 'eg/twinkle_twinkle.mid' ],
    ngram_size   => 3,
    patches      => [qw( 68 69 70 71 72 73 )],
    random_patch => 1,
    bounds       => 1,
  );

  my $analysis = $mng->process;
  print $analysis;

  my $playback = $mng->populate;
  print $playback;

  $mng->write;

  # Analyze multitrack tunes
  $mng = MIDI::Ngram->new(
    in_file => [ '/multi/channel/tune1.mid', '/multi/channel/tune2.mid' ],
  );

  $mng->process;

  # Dump out the channel 0 duration phrases in order
  print Dumper [
    map { "$_ => " . $mng->dura->{0}{$_} }
      sort { $mng->dura->{0}{$a} <=> $mng->dura->{0}{$b} }
        keys %{ $mng->dura->{0} }
  ];

  # Dump out the channel 0 note phrases in order
  print Dumper [
    map { "$_ => " . $mng->notes->{0}{$_} }
      sort { $mng->notes->{0}{$a} <=> $mng->notes->{0}{$b} }
        keys %{ $mng->notes->{0} }
  ];

  # Inspect the phrase transition networks
  print Dumper $mng->dura_net;
  print Dumper $mng->note_net;

DESCRIPTION

MIDI::Ngram parses a given list of MIDI files, finds the top repeated note phrases, builds the analysis, transition network, and renders to a MIDI file if desired.

ATTRIBUTES

in_file

Required. An Array reference of MIDI files to process.

ngram_size

Ngram phrase size.

Default: 2

max_phrases

The maximum number of phrases to analyze/play.

Default: 10

Setting this to a value of 0 analyzes all phrases.

bpm

Beats per minute.

Default: 100

durations

The optional MIDI note durations to choose from (at random).

Default: [] (i.e. use the computed dura phrases instead)

Using a setting of ['qn'] allows you to evenly inspect the phrases during audio playback.

patches

The patches to choose from (at random) if given the random_patch option.

Default: [0 .. 127]

random_patch

Boolean. Choose a random patch from patches for each channel.

Default: 0 (meaning "use the piano patch")

out_file

MIDI output file.

Default: midi-ngram.mid

pause_duration

Insert a rest of the given duration after each phrase.

Default: '' (no resting)

analyze

Array reference of the channels to analyze. If not given, all channels are analyzed.

Default: undef

loop

The number of times to choose a weighted phrase. * This only works in conjunction with the weight option.

Default: 10

weight

Boolean. Play phrases according to the probability of their repetition occurrence with the function "choose_weighted" in List::Util::WeightedChoice.

Default: 0

shuffle_phrases

Boolean. Shuffle the non-weighted phrases before playing them.

Default: 0

single_phrases

Boolean. Allow single occurrence ngrams.

Default: 0

one_channel

Boolean. Accumulate phrases onto a single channel.

Default: 0

bounds

Boolean. Include pitch range in the analysis.

Default: 0

score

The score object in "MAIN-ROUTINES" in MIDI::Simple. Constructed by the populate method.

notes

The hash-reference bucket of pitch ngrams. Constructed by the process method.

dura

The hash-reference bucket of duration ngrams. Constructed by the process method.

dura_net

A hash-reference ngram transition network of the durations. Constructed by the process method.

note_net

A hash-reference ngram transition network of the notes. Constructed by the process method.

METHODS

new

  $mng = MIDI::Ngram->new(%arguments);

Create a new MIDI::Ngram object.

process

  $analysis = $mng->process;

Find all ngram phrases and return the note analysis.

populate

  $playback = $mng->populate;

Add notes to the MIDI score and return the playback notes.

write

  $mng->write;

Write out the MIDI file.

SEE ALSO

Moo

Lingua::EN::Ngram

List::Util

List::Util::WeightedChoice

Music::Note

MIDI::Simple

MIDI::Util

Music::Gestalt

AUTHOR

Gene Boggs <gene@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2020 by Gene Boggs.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm MIDI::Ngram

perl -MCPAN -e shell
install MIDI::Ngram