Windows binaries for the sfarkxtc tool, use it to take soundfonts and convert them from .sfark into .sf2. A fork of https://github.com/raboof/sfArkXTm

Download+Usage

Go to the releases tab on Github and download the latest release that says "win64". Unzip the zip file.

Copy a .sfark file into the same directory as sfarkxtc. From the commandline, run a command like

sfarkxtc.exe mySoundfont.sfark mySoundfont.sf2

and it will extract the .sf2!

For quiet mode (shows less output), use

sfarkxtc.exe mySoundfont.sfark mySoundfont.sf2 --quiet

Why sfark?

sfArk still compresses .sf2 files significantly better than even modern .7z and .rar compression. I want to store my files in a format that will still be readable, even 20 years in the future, though, so any type of unique or proprietary format is dangerous. How should I store my soundfonts?

• Store the full .sf2 files
  • Pros: no need to decompress
  • Cons: heavy disk space use
• Store in .tar.gz, .xz, or .7z format
  • Pros: software to decompress is open-source and available
  • Cons: does not compress .sf2 files very well, even with a large buffer size
• Store in .sfpack format
  • Pros: very good compression ratio
  • Cons: no open source decompression = unsafe for long term storage!
  • More notes
• Store in .sfark format
  • Pros: very good compression ratio
  • Pros: some tools like SynthFont can read .sfark directly
  • Pros: easily automate decompression via cmd line tool
  • Pros: open source decompression available
  • Cons: sfark seems to rely on x86-like architectures

(In 2012, j_e_f_f_g, who wrote "unsfark", claimed that sfark is an extremely fragile format relying on intel rounding errors, but this has been disputed by further research... and we'll probably have some sort of x86 emulator available for a long time. The fact that sfarkxtc will build and work targeting both x86 and x86-64, and on linux and mac, is a good sign. If you are converting many sf2 files to sfark, see my batch convert sf2 to sfark tool here which also confirms that the resulting sfark file can be decoded by sfarkxtc with 100% fidelity.)

Conclusion: If disk space is at a premium, use sfark, otherwise, use xz or 7z.

Building from source

There are many ways to accomplish this, here's a pretty straightforward route:

• Get the latest sfarkxtc-windows source
  • for example git clone https://github.com/moltenform/sfarkxtc-windows.git
• Go to https://rubyinstaller.org/downloads/
• Download "Ruby+DevKit" for x64, for example rubyinstaller-devkit-2.5.3-1-x64.exe
• Run this installer, it will set up a working mingw/msys2 environment
• I'll assume ruby was installed to C:\ruby\Ruby25-x64, replace this below if you used a different directory
• Open the directory C:\ruby\Ruby25-x64\msys64
• Run msys2_shell.cmd to open a msys2 shell.
• cd to where the sfarkxtc-windows source is.
  • Remember that you need to use / forward slashes in the path, not backslashes.
• Run make
  • if you get the error make: g++: Command not found
  • add g++ to the PATH by running
  • export PATH=$PATH:/c/ruby/Ruby25-x64/msys64/mingw64/bin
• Optional: for additional security, you can build with Duma enabled.
  • adds protection against potential memory bugs triggered by malformed sfark files
  • build Duma to get libduma.a (my notes on building Duma)
  • copy libduma.a to sfarkxtc-windows/src/duma
  • run make USE_DUMA=1
• Optional: for additional security, you can build with stack protection.
  • adds protection against potential overflow bugs triggered by malformed sfark files
  • I recommend running pacman -Syu a few times to get the latest MSYS2
  • the 2018 version of MSYS2 I had was affected by this bug; enabling stack protection caused crashes in every function.
  • run make USE_DUMA=1 PROTECT_STACK=1
• There should now be a file sfarkxtc_out.exe
• Copy C:\ruby\Ruby25-x64\msys64\mingw64\bin\zlib1.dll into the same directory as sfarkxtc_out.exe
• Copy C:\ruby\Ruby25-x64\msys64\mingw64\bin\libssp-0.dll into the same directory as sfarkxtc_out.exe
• Done!

Tests

• cd to src/test
• Run python test_sfarkxtc.py
• Tests cover all four Compression Strength levels, and all combinations of the presence/absence of notes+license information.

Zlib

For the truly paranoid (I guess I'll have to include myself here) I've included the source of zlib, in case I'm trying to build this 20 years in the future and it's hard to find the right version of zlib's source. The easiest way for it to be built on Windows is to:

(use a mingw shell as described above)
(untar the archive)
(cd into the directory)
make -f win32/Makefile.gcc BINARY_PATH=/bin INCLUDE_PATH=/usr/local/include LIBRARY_PATH=/usr/local/lib

This will generate zlib1.dll and so on. You can now modify sfarkxtc's Makefile to point to the newly built zlib, and modify all headers that refer to "zlib.h" to a relative path like "zlib-1.2.11/zlib.h".