GENMIDI.OP2 OPL2 sound bank: Perl parsing library

GENMIDI.OP2 is a sound bank file used by players based on DMX sound library to play MIDI files with General MIDI instruments using OPL2 sound chip (which was commonly installed on popular AdLib and Sound Blaster sound cards).

Major users of DMX sound library include:

  • Original Doom game engine (and games based on it: Heretic, Hexen, Strife, Chex Quest)
  • Raptor: Call of the Shadows

File extension

op2

KS implementation details

License: CC0-1.0

This page hosts a formal specification of GENMIDI.OP2 OPL2 sound bank using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Perl source code to parse GENMIDI.OP2 OPL2 sound bank

GenmidiOp2.pm

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

use strict;
use warnings;
use IO::KaitaiStruct 0.007_000;
use Encode;

########################################################################
package GenmidiOp2;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{magic} = $self->{_io}->ensure_fixed_contents(pack('C*', (35, 79, 80, 76, 95, 73, 73, 35)));
    $self->{instruments} = ();
    my $n_instruments = 175;
    for (my $i = 0; $i < $n_instruments; $i++) {
        $self->{instruments}[$i] = GenmidiOp2::InstrumentEntry->new($self->{_io}, $self, $self->{_root});
    }
    $self->{instrument_names} = ();
    my $n_instrument_names = 175;
    for (my $i = 0; $i < $n_instrument_names; $i++) {
        $self->{instrument_names}[$i] = Encode::decode("ASCII", IO::KaitaiStruct::Stream::bytes_terminate(IO::KaitaiStruct::Stream::bytes_strip_right($self->{_io}->read_bytes(32), 0), 0, 0));
    }
}

sub magic {
    my ($self) = @_;
    return $self->{magic};
}

sub instruments {
    my ($self) = @_;
    return $self->{instruments};
}

sub instrument_names {
    my ($self) = @_;
    return $self->{instrument_names};
}

########################################################################
package GenmidiOp2::InstrumentEntry;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{flags} = $self->{_io}->read_u2le();
    $self->{finetune} = $self->{_io}->read_u1();
    $self->{note} = $self->{_io}->read_u1();
    $self->{instruments} = ();
    my $n_instruments = 2;
    for (my $i = 0; $i < $n_instruments; $i++) {
        $self->{instruments}[$i] = GenmidiOp2::Instrument->new($self->{_io}, $self, $self->{_root});
    }
}

sub flags {
    my ($self) = @_;
    return $self->{flags};
}

sub finetune {
    my ($self) = @_;
    return $self->{finetune};
}

sub note {
    my ($self) = @_;
    return $self->{note};
}

sub instruments {
    my ($self) = @_;
    return $self->{instruments};
}

########################################################################
package GenmidiOp2::Instrument;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{op1} = GenmidiOp2::OpSettings->new($self->{_io}, $self, $self->{_root});
    $self->{feedback} = $self->{_io}->read_u1();
    $self->{op2} = GenmidiOp2::OpSettings->new($self->{_io}, $self, $self->{_root});
    $self->{unused} = $self->{_io}->read_u1();
    $self->{base_note} = $self->{_io}->read_s2le();
}

sub op1 {
    my ($self) = @_;
    return $self->{op1};
}

sub feedback {
    my ($self) = @_;
    return $self->{feedback};
}

sub op2 {
    my ($self) = @_;
    return $self->{op2};
}

sub unused {
    my ($self) = @_;
    return $self->{unused};
}

sub base_note {
    my ($self) = @_;
    return $self->{base_note};
}

########################################################################
package GenmidiOp2::OpSettings;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{trem_vibr} = $self->{_io}->read_u1();
    $self->{att_dec} = $self->{_io}->read_u1();
    $self->{sust_rel} = $self->{_io}->read_u1();
    $self->{wave} = $self->{_io}->read_u1();
    $self->{scale} = $self->{_io}->read_u1();
    $self->{level} = $self->{_io}->read_u1();
}

sub trem_vibr {
    my ($self) = @_;
    return $self->{trem_vibr};
}

sub att_dec {
    my ($self) = @_;
    return $self->{att_dec};
}

sub sust_rel {
    my ($self) = @_;
    return $self->{sust_rel};
}

sub wave {
    my ($self) = @_;
    return $self->{wave};
}

sub scale {
    my ($self) = @_;
    return $self->{scale};
}

sub level {
    my ($self) = @_;
    return $self->{level};
}

1;