Emusound

A permissive cross-platform sound library for games, designed to play sound files from old consoles (NES, SNES etc) via their native file format as if they were regular sound files. In addition to this, it is also able to play regular audio files in the common formats of either .wav, .mp3, .ogg or .flac. Basic sound filters are also supported for all sound files!

There is also support for generating waveform sounds in the format of square, sine, triangle or sawtooth. You can also generate noise sounds.

Emusound has no external dependencies you need to carry around, and can easily be statically built in to your game executable, without any need for an external .dll-file.

Sounds can be read from files or directly from memory. The files read from memory in the demo has been embedded by using f2src to generate source files with file data.

Supported file types for playback

Consoles

• AY - ZX Spectrum/Amstrad CPC
• GBS - Nintendo Game Boy
• GYM - Sega Genesis/Mega Drive
• HES - NEC TurboGrafx-16/PC Engine
• KSS - MSX Home Computer/other Z80 systems (doesn't support FM sound)
• NSF/NSFE - Nintendo NES/Famicom (with VRC 6, Namco 106, and FME-7 sound)
• SAP - Atari systems using POKEY sound chip
• SPC - Super Nintendo/Super Famicom
• VGM - Sega Master System/Mark III, Sega Genesis/Mega Drive,BBC Micro

Regular

• WAV - Waveform Audio File Format
• MP3 - Moving Picture Experts Group, Audio Layer III
• OGG - Ogg audio format
• FLAC - Free Lossless Audio Codec

Minimalistic design

Emusound is designed with the minimalist in mind! If you don't need support for certain formats in your project, you can easily remove it from the library during build. This can be configured in the CMakeLists.txt file, or through the CMake GUI application, for simplicity:

Compiling

Emusound uses CMake for compilation, and should be straightforward to compile on all platforms. Either open the CMakeLists.txt in CMake GUI, or use the simple cmake CMakeLists.txt command in the root folder of this project. Alternatively you can also open the project in an IDE or code editor like Visual Studio Code and compile from there. Windows, Linux and Mac OSX are all supported.

Before compiling, you'll have to get some submodules to be able to compile the demo. The command for this should be git submodule update --init --recursive.

Demo

There is a demo-application that demonstrates the functionality in Emusound. Even though emusound itself can be built both statically (as .lib/.a) and dynamically (as .dll / .so), the demo requires a static build to compile. This is controlled by the parameter BUILD_SHARED_LIBS in the CMakeLists.txt, which is off by default (in other words: static).

NOTE: Press Esc/Escape if you want to exit the application. The STOP! button for every form will stop all sounds related to the actual form.

Waveforms form

Here you can produce your own Square/Sine/Triangle and Sawtooth sounds. You must press the Play button to hear the actual sound. You can change the tone by changing the frequency, or press the Send to piano button to be able to press what tone you are looking for, and the frequency will be adjusted based on which tone you choose.

Emu music form

Here you can play emulated sound files. These files can support several tracks in one file. NSF/NSFE typically has several tracks in the file, but for this example only the NSFEhas several tracks. You can change tracks with <- or ->. If you press the Filter button, you can apply sound filters to the actual sound. You must manually mark filters as active to activate them. The Seek button will jump to a specific location in the file. This can be controlled by the common Seek value in the bottom of the form.

Music form

Works the same as the Emu music form, but plays regular sound files.

Filters

When pressing the Filter button on a chosen track in the Emu music or Music form, you can apply sound filters to the audio. Supported filters are:

• Biquad
• Lowpass
• Highpass
• Bandpass
• Peaking EQ
• Notching
• Lowshelf
• Highshelf

Noise

Can produce noise sounds. These can be a bit loud, so be careful when adjusting the seed/amplitude/volume. The npoises supported are:

• White
• Pink
• Brownian

NOTE: The demo uses content from the emusound/content folder, and uses relative paths to find the folder. Thus the path of the application must have a position that are relative to the content folder in the same way as in this picture (otherwise the content will not be found):

Libraries

Although emusound has everything built in to prevent external dependencies, there are external dependencies used to make this library possible!

These are:

• miniaudio - For playing audio / communicating with audio driver.
• Game_Music_Emu (fork on github) (from blargg's homepage (currently unavailable)) - Used for emulating the sound chip of each retro console. This library is LGPL-licensed, but I got permission to use it under a more permissive license.

Used for the demo application:

• SFML - For sound streaming, window, clipboard and displaying graphics.
• Dear ImGui - For anything GUI related.

Credits

• Necrophageon - Creator of the music used in the NSF example
• Juhani Junkala ([email protected]) - Creator of the music used for ogg/wav/mp3/FLAC examples.