MODPlay

Yet another simple MOD player library written in C. But I don't care, because this one's mine. Supports up to 32-channel files by default (though this can be changed by editing the header file).

To hear for yourself how it sounds, you may visit this website, which uses this exact library (compiled to WebAssembly with Emscripten), wrapped around a nice Windows 3.11-themed UI. There are several examples available to pick from, but you may also upload your own files (OUTDATED - only supports 4-channel files).

A simple example program is supplied with this library, which uses SDL for audio output. To compile it, run the following:

cc example.c modplay.c -lSDL -o example

There are two valid ways to use this library: via an audio callback (whose buffer will be filled by RenderMOD()) or via repeatedly callingProcessMOD(). Use the former whenever it is possible, unless you want to write your own Paula emulator. Use the latter only when hardware restrictions limit you from setting up an audio callback, and said hardware contains a dedicated hardware sampler/mixer, for which you will have to write a translation layer to translate Paula parameters to the hardware's native parameters (e.g. the original Sony PlayStation).

DO NOT USE BOTH AT ONCE! Only use the RenderMOD() method, or the ProcessMOD() method. RenderMOD() calls ProcessMOD() internally by itself, by calling both functions, the player will misbehave badly.

Projects using this library

• cpldcpu/ModPlayRISCV - MOD player for the CH32V002 RISC-V microcontroller
• prochazkaml/pico-MODPlay - MOD player for the RP2040 microcontroller
• prochazkaml/webMODPlay - web-based MOD player (as described above)

If you made your own project using this library, please let me know!

Library compiled size

Compiled with the default number of channels:

Compiler	Arch	.text	.data	.bss
clang 21.1.4 (-O0)	amd64	9046	0	3152
clang 21.1.4 (-O3)	amd64	6133	0	3152
clang 21.1.4 (-Os)	amd64	4373	0	3152
clang 21.1.4 (-O0)	i386	7022	0	2632
clang 21.1.4 (-O3)	i386	5477	0	2632
clang 21.1.4 (-Os)	i386	3914	0	2632
clang 21.1.4 (-O0)	aarch64	9940	0	3152
clang 21.1.4 (-O3)	aarch64	5392	0	3152
clang 21.1.4 (-Os)	aarch64	4256	0	3152
clang 21.1.4 (-O0)	armv7m	6032	0	2632
clang 21.1.4 (-O3)	armv7m	4596	0	2632
clang 21.1.4 (-Os)	armv7m	3084	0	2632

Compiled for 4 channels maximum:

Compiler	Arch	.text	.data	.bss
clang 21.1.4 (-O0)	amd64	9046	0	912
clang 21.1.4 (-O3)	amd64	6133	0	912
clang 21.1.4 (-Os)	amd64	4373	0	912
clang 21.1.4 (-O0)	i386	7022	0	616
clang 21.1.4 (-O3)	i386	5493	0	616
clang 21.1.4 (-Os)	i386	3919	0	616
clang 21.1.4 (-O0)	aarch64	9940	0	912
clang 21.1.4 (-O3)	aarch64	5448	0	912
clang 21.1.4 (-Os)	aarch64	4256	0	912
clang 21.1.4 (-O0)	armv7m	5994	0	616
clang 21.1.4 (-O3)	armv7m	4616	0	616
clang 21.1.4 (-Os)	armv7m	3108	0	616

Supported effects

The following list was taken from the OpenMPT wiki.

Eff	Name	Category	Supported
0xy	Arpeggio	Pitch	✓
1xx	Portamento Up	Pitch	✓
2xx	Portamento Down	Pitch	✓
3xx	Tone Portamento	Pitch	✓
4xy	Vibrato	Pitch	✓
5xy	Volume Slide + Tone Portamento	Volume + Pitch	✓
6xy	Volume Slide + Vibrato	Volume + Pitch	✓
7xy	Tremolo	Volume	✓
8xx	Set Panning	Panning	- (non-standard)
9xx	Sample Offset	Other	✓
Axy	Volume Slide	Volume	✓
Bxx	Position Jump	Global	✓
Cxx	Set Volume	Volume	✓
Dxx	Pattern Break	Global	✓
E0x	Set Filter	Other	- (and never will be, there is no filter to begin with)
E1x	Fine Portamento Up	Pitch	✓
E2x	Fine Portamento Down	Pitch	✓
E3x	Glissando	Pitch	- (not widely supported anyway)
E4x	Set Vibrato Waveform	Pitch	✓
E5x	Set Finetune	Pitch	✓
E60	Pattern Loop Start	Global	✓
E6x	Pattern Loop	Global	✓
E7x	Set Tremolo Waveform	Volume	✓
E8x	Set Panning	Panning	- (non-standard)
E9x	Retrigger	Other	✓
EAx	Fine Volume Slide Up	Volume	✓
EBx	Fine Volume Slide Down	Volume	✓
ECx	Note Cut	Other	✓
EDx	Note Delay	Other	✓
EEx	Pattern Delay	Global	✓
EFx	Invert Loop	Other	- (noone is sure what it even does)
Fxx	Set Speed / Tempo	Global	✓