OptionalprogressA function to allow showing progress long operations. It can be undefined.
If the RIFS (64-bit RIFF chunks) should be used. Increases maximum size from 4GB to effectively infinite. Recommended, since SFE 4 is effectively incompatible with SF2.
The ISFT field to set when writing. If unset, SpessaSynth is written.
This field indicates the last software that was used to edit this sound bank.
Options for writing an SFE 4 file.