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@ -12,11 +12,17 @@ At a technical level: the emulator has channels comprised of 2 oscillators each.
## Caveats and Limitations ##
Before I wrote this, I didn't know much about VST or the OPL at a technical level. This is the first VST plugin I've written. The sample rate is locked at 44.1 kHz. In hindsight I would have implemented things a bit differently, but it all basically works, and is now reasonably well tested.
Before I wrote this, I didn't know much about VST or the OPL at a technical level. This is the first VST plugin I've written. In hindsight I would have implemented things a bit differently, but it all basically works, and is now reasonably well tested.
One thing I have learned is that all VST hosts are not created equal. I only really work with Renoise. Your mileage may vary.
Note that I started and work on this project for fun. I'm not accepting donations, but any contributions in the form of code, SBI files, links to music you've created etc are very welcome and help keep me motivated.
Please also understand that I also write software full time for a living and have a life outside of software development.
## How do I use it? ##
Each instance of the plugin emulates an entire OPL chip, but polyphony is implemented by using a channel per note. Parameter changes applied to all channels. With this plugin, essentially you are just working with two operators.
Each instance of the plugin emulates an entire OPL chip, but with this plugin, essentially you are just working with two operators: the carrier and modulator.
Some documentation which may be useful:
@ -26,9 +32,25 @@ Some documentation which may be useful:
- [AdLib programming guide](http://www.shipbrook.net/jeff/sb.html) Dates back to 1991!
- [Another programming guide](http://www.ugcs.caltech.edu/~john/computer/opledit/tech/opl3.txt) This one is for the OPL3, but most of the information still applies.
### Percussion
## What can it do? ##
Percussion mode is now supported! This mode is not very well documented, even in the original Yamaha documentation. It works with the DOSBox emulator, but doesn't seem to work too well in the ZDoom emulator. Here are some tips on using it based on experimentation and looking at the DOSBox source code.
Here are some examples:
- [Demo showing how parameters affect sound](https://www.youtube.com/watch?v=yU0CWQ66Z28)Thanks estonoesunusuario!
- [Dune 2 music reproduced using the plugin](https://www.youtube.com/watch?v=w6Lu0C_vZwQ)Great work by Ion Claudiu Van Damme
- [Tyrian remix](https://www.youtube.com/watch?v=ZGwhKVFMCqM) by Block35 Music
- [Syndicate theme](https://www.youtube.com/watch?v=HI7U5XxTSW0) demo I created for the first release
- (your link here...)
### SBI FIles ###
SBI files are an instrument file format developed by Creative Labs back in the day for the Sound Blaster. Essentially they work as presets for this plugin. Just drag and drop them into the plugin window!
I've collected a bunch of presets in this repository. I've also added support for saving SBI files. Please contribute!
### Percussion ###
Percussion mode is now supported! This mode is not very well documented, even in the original Yamaha documentation. Here are some tips on using it based on experimentation and looking at the DOSBox source code.
- Bass drum: Uses both operators. Essentially just doubles output amplitude?
- Snare: Uses carrier settings. Abs-sine waveform recommended.
@ -38,17 +60,15 @@ Percussion mode is now supported! This mode is not very well documented, even in
Also, some [much more detailed notes](http://midibox.org/forums/topic/18625-opl3-percussion-mode-map/) on percussion mode based on experimentation with real hardware!
## How did you create the instrument programs? ##
To figure out the parameters used by the original games, I just added a printf to the DOSBox OPL emulator, compiled DOSBox, ran the games, and captured their output as raw register writes with timestamps.
I hacked together a Python script which parses the raw output, identifying unique instruments and outputting the parameter values.
## How did you do this? ##
## How did you create this? ##
The emulation (ie, the hard part!) is taken straight from the excellent DOSBox and ZDoom projects. I also used a function from libgamemusic by Adam Nielsen for converting frequencies from Hertz into the "FNUM" values used by the OPL.
The emulation (ie, the hard part!) is taken straight from the excellent DOSBox project. I also used a function from libgamemusic by Adam Nielsen for converting frequencies from Hertz into the "FNUM" values used by the OPL.
The VST was written using Juce, a cross-platform C++ library inspired by the Java JDK. Among other things, Juce provides a GUI for generating boilerplate for audio plugins.
@ -56,13 +76,13 @@ The code I wrote is essentially a device driver for the emulated OPL, implementi
## Building ##
So far I've only built under Windows. Thanks to the hard work of others, OSX and Linux builds should be coming very soon!
So far I've only built under Windows. Thanks to the hard work of Jeff Russ, there is also an OSX build, but I currently have no way to build it myself on OSX..
### Windows Build Instructions ###
1. Download Juce (http://www.juce.com/)
2. Download the VST SDK (http://www.steinberg.net/en/company/developer.html)
3. Run "The Introjucer" executable included in Juce.
3. Run "The Projucer" executable included in Juce.
4. Open JuceOPLVSTi.jucer
- Make any changes to the GUI layout and components here (PluginEditor.cpp).
- Save PluginEditor.cpp if modified