Introduction

This is a collection of VST instruments that emulate MIDI drivers for OPL3 based sound cards. The synthesizer code is based on the Windows OPL3 drivers from this thread

Included synths

• Apogee OPL3: Based on Apogee Sound System source code.
• Doom OPL3: Based on Chocolate Doom source code.
• Windows 9x OPL3: Based on Windows 9x Sound Blaster 16 driver reverse engineering.

Installation and usage notes

Included Apogee patches

• built in patch - ROTT 1.3, Build engine games setup utility.
• apogee_blood.tmb - Blood
• apogee_default.tmb - Copy of built in patch
• apogee_duke3d.tmb - Duke Nukem 3D
• apogee_lee.tmb - ROTT 1.0-1.2
• apogee_nam.tmb - NAM
• apogee_sw.tmb - Shadow Warrior(Shareware)

Default Apogee patch installation

1. Create OPLSynth folder in C:\ disk root.
2. Copy *.tmb files to C:\OPLSynth folder.
3. Copy needed tmb file as apogee.tmb
4. If you want to use built in patch remove apogee.tmb

Included Doom patches

• built in patch - DMX, Heretic, Hexen, Doom Beta, Strife Demo
• dmx_dmx.op2 - Copy of built in patch
• dmx_doom1.op2 - Doom, Ultimate Doom, Chex Quest
• dmx_doom2.op2 - Doom II, Final Doom
• dmx_strife.op2 - Strife
• dmx_raptor.op2 - Raptor
• dmxopl.op2 - DMXOPL3

Default Doom patch installation

1. Create OPLSynth folder in C:\ disk root.
2. Copy *.op2 files to C:\OPLSynth folder.
3. Rename needed op2 file to genmidi.op2.
4. If you want to use built in patch remove genmidi.op2

DMXOPTION toggles

• OPL3 mode enable: Set DMXOPTION environment variable to "-opl3"
• Doom 1 1.666 mode enable: Set DMXOPTION environment variable to "-doom1"
• Doom 2 1.666, Heretic, Hexen mode enable: Set DMXOPTION environment variable to "-doom2"

You also can combine OPL3 mode with Doom 1.666 modes. eg set variable to "-opl3-doom1"

Automatable parameters

• Volume: Synth master volume.
• VolumeDisplay: Sets the unit for displaying the aforementioned Volume parameter, either dB or %.
• DCBlock: Filters out DC offset from the final output.
• NoiseGate: Gates low level noise from the final output.
• Transpose: Applies an offset to Incoming MIDI notes.
• Emulator: Selects the OPL3 emulator that will be used. Nuked Is more accurate, while DOSBox runs faster.
• HQResample: Internally Runs OPL3 emulation at the native OPL3 sample rate (49716 hZ), then resamples to the host sample rate using a decent algorithm.
• PushMidi: Queue's MIDI events Instead of processing them Immediately. Queued events have sample accurate timing, while immediate events can have jittery playback with large audio buffers.

What's with the GUI?

The User Interfaces of most audio plugins draw graphics directly to the screen. The problem with this approach Is that these controls aren't seen by assistive technology such as screen readers, which are designed to work with native Operating System controls. This project aims to change that. The UI has been programmed from the ground up using raw Win32 with mostly standard controls, The only exception being the Virtual MIDI Keyboard.

Virtual MIDI Keyboard cheat sheet

• Number row: Select octave.
• Top row: Sharp notes.
• Home row: Flat notes.
• Bottom row: Select velocity.
• Shift: Sustain.
• Up arrow: Increase velocity.
• Down arrow: Decrease velocity.
• Right arrow: Increase octave.
• Left arrow: Decrease octave.
• Page down: Move to next Instrument.
• Page up: Move to previous Instrument.
• End: Increase active channel.
• Home: Decrease active channel.
• =: Increase bend MSB.
• -: Decrease bend MSB.
• : Increase bend LSB.
• `: Decrease bend LSB.
• Backspace: Reset pitch bend and program to current keyboard state.
• Space: Reset keyboard state.

Extra notes

• This is only a VST2 compatible plug-in. A VST3 version Is not planned for various reasons.

Building from source

In order to build OPL3GM you will need

• Microsoft Visual Studio 2005
• Windows Server 2003 Platform SDK
• InnoSetup 5.4.3
• 7-Zip

After installing, just run build.bat. You may need to change the paths defined in this script to correspond with your installation of the build tools.

License

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

Creddits

• Nukeykt, for writing the Nuked OPL3 emulator and the MIDI drivers that this project is based on.
• Wohlstand, for applying various updates to the aforementioned MIDI drivers.
• The DOSBox Team, for providing a faster alternative to the Nuked OPL3 emulator.
• Kode54, for providing a high quality resampler.
• Me, for writing the VST interface for this synth.
• Developers in the 90s, for creating the original MIDI drivers that this project replicates, as well as the included instrument banks.
• Sneakernets, for creating the DMXOPL patch set.
• Old blogs and forums, for tips on VST development.