Ray706 / freepats-tools

Tools to manage, create and convert sound fonts

FreePats-Tools

Tools to manage, create and convert sound fonts, collections of sampled musical instruments and sound banks. Originally created for the FreePats project: http://freepats.zenvoid.org/

Dependencies

Requires Python 3 with dateutil, soundfile and numpy modules. This will install the required dependencencies on Debian and derived distributions:

apt-get install python3 python3-dateutil python3-soundfile python3-numpy

Usage

There are two programs included:

• createSFZ.py: Takes audio files as input and writes to stdout a SFZ template for them.

• convertSoundBank.py: Process a sound bank and writes another file, possibly converted to a different format.

createSFZ.py is useful to create a new sound bank in SFZ format. It accepts a collection of samples as a list of arguments and writes a template to the standard output.

The SFZ format is composed of text that can be modified with any text editor to complete the missing parts. Later, it can be converted to other formats with the convertSoundBank.py program.

createSFZ.py will try to guess the pitch of each sample from its file name. For this reason, each sample must be named with a suffix indicating its note. It accepts either standard MIDI numbers (where 60 is middle C), or English alphabetic notation plus an octave number (where C4 is middle C).

Examples:

createSFZ.py piano_C4.wav piano_C5.wav piano_F#4.wav piano_F#5.wav
createSFZ.py samples/*.wav > soundBank.sfz

Generated output will look like this:

//+ Name: Unnamed sound bank
//+ Date: 2016-12-19

<global>
 //+ Instrument: Unnamed instrument
 ampeg_release=0.5

<group>
 loop_mode=no_loop
<region>
 hikey=62
 pitch_keycenter=60
 sample=piano_C4.wav
<region>
 lokey=63
 hikey=68
 pitch_keycenter=66
 sample=piano_F#4.wav
<region>
 lokey=69
 hikey=74
 pitch_keycenter=72
 sample=piano_C5.wav
<region>
 lokey=75
 pitch_keycenter=78
 sample=piano_F#5.wav

Lines starting with // are comments. Lines starting with //+ contain hints that will be processed by these tools to provide additional information and aid conversion between different formats. They will be ignored by SFZ players.

There are a few things that should be edited. In particular:

• Name of the sound bank and instrument. For compatibility with the SF2 format, the instrument name should be no longer than 19 characters.

• If samples contain loops, loop_mode instruction should be modified and each sample should have loop_start and loop_end information added.

convertSoundBank.py can be used to validate and convert the SFZ file. When converted to SF2, global options included within <global> will be converted to global instrument options that can be overriden in subsequent groups or regions.

This example will create a SF2 sound font.

convertSoundBank.py grandPiano.sfz grandPiano.sf2

The resulting file grandPiano.sf2 should be ready to be used with fluidsynth, qsynth, or any other program that handle SF2 files. It can also be open with a sound font editor (swami, polyphone...) and inspect or continue editing its contents.

Limitations

This software is in development and currently supports a small set of features.

• Only SFZ to SF2 conversion is available. The opposite conversion from SF2 to SFZ is not done yet. Other formats are missing.

• Supports a minimal subset of SFZ opcodes.

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 3 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.