Making an .sfz...What should I know?

[tonaliszt]

Hi all,

After hearing over and over that people would like .sfz versions of my instruments (Alpine Project Stuff), I've given in and am considering it.  

The things is that my instruments use a lot of special Kontakt features (legato, automated filters, etc), that I don't think can be ported to .sfz.  But I figured I could resample the Kontakt instruments, and put them in Sam's .sfz auto mapper.  

I figured that I should resample them completely dry, but I have other questions, like how many velocity layers to sample (I can theoretically do 127, because the filters are on a CC).  Other than that, what else should I know?  

I also want to create a soundfont out the .sfzs at some point to work with musescore, so I don't know exactly how different things will be in sfz vs sf2.  

Thanks, (I really hope this post is clear)
Noah

[Samulis]

SFZ is *theoretically* capable of dynamic crossfading. I've done some research here in the forum on it, but never tested. It has the ability to set velocity-based xfade low and high points (so you can do non-continuous crossfading), and I believe it is possible to also do modwheel (continuous/dynamic) crossfading. EDIT: On second thought, GPO has modwheel control, so it has to be possible.

My automapper is not yet designed to do crossfading, although it's on the features list when I figure out the correct process (it's been on the backburner compared to doing things that help me support myself financially). Other than that, it's very robust. It can easily handle multi-thousand sample runs and unlike many mapping tools has no problem with missing RR's or changing dynamic layers across instruments. It can be a little confusing at first and has a few little workarounds regarding file path selection, but hey, I managed to figure it out, so I figure it isn't that bad- just watch the videos on youtube. There are a few simple things you need to check with file names to get them in the format the automapper likes (we went for the "make it dumb simple" instead of "make it dumb complicated" with regards to how it figures out what each argument is), but a simple batch renamer can do that so easily.

I don't think there is a faux legato, but it DOES support true legato samples with various trigger mode opcodes. Again, the documentation is so poor there's no way to really figure it out without experimenting. There's probably some way you can do faux legato or at least monophonic mode. EDIT: On second thought, GPO has faux legato, so it has to be possible.

Automated filters are totally feasible, although with SFZ 2.0 there's some confusion on how to implement effects as it changed vs. SFZ 1.0. Unfortunately virtually all of the online documentation is for 1.0. There is a book that discusses 2.0 in one chapter, but it isn't much more helpful than the online resources (which I will link below). You can even have things have random ranges which is pretty cool for humanizing (such as random attack delay or random pitch changes or random volume or whatnot). Humanizing is thus very feasible and quite easy to do.

Soundfonts and SFZ's have virtually nothing in common. Soundfonts are a monolithic, old-school format incapable of multisampling (RR's) and with innumerable drawbacks. SFZ is non-monolithic and theoretically very powerful- it just lacks a built-in DRM/licensing system, a standardized UI system (UI's, if present, have to be built by hand in XML), and documentation required to make it a viable professional/commercial format.

I don't think you should resample. I think you can use the xfade opcodes to get the exact same result with much better efficiency although ARIA at least does DFD natively.

Some basic rules of thumb:
- If you want something applied to all samples, put it in a "Global" area and save some space.
- You can't embed a <group> within a <group> (because SFZ doesn't require or even recognize ends and auto-adds them when compiling), so you have to use <global> or aria-specific <master> to apply things in multiple layers (e.g. having a set of <group>s all on the same KS conveniently).
- You can edit a SFZ while it is loaded and it will auto-update when you save it, at least in ARIA.
- The Find & Replace function is your bestest friend in the whole wide world.
- Delete the '/' in the Path=/... bit near the top if one appears or else it won't work on Macs (it's a bug with the automapper I need to get fixed).

Resources for SFZ:
http://www.sfzformat.com/legacy/ (SFZ 1.0 spec)
https://web.archive.org/web/200903190010...ge/sfz.asp (same as above pretty much)
https://docs.google.com/document/d/1UxPa...E6xino/pub (SFZ 2.0-ish- LinuxSampler spec)
https://www.linuxsampler.org/sfz/ (total list of pretty much every opcode in existence)
http://drealm.info/sfz/plj-sfz.xhtml (alt. documentation of SFZ by a Peter Jones- very useful)
http://plogue.com/phpBB3/viewtopic.php?f=14&t=4389 (ARIA-specific Opcodes)

[tonaliszt]

Thanks Samulis! This is exactly the kind of info I was looking for.

I am going to ask around on the musescore forums to see how sfz are being implemented in the nightly builds.

If anyone else has other tips and tricks, they would be very much appreciated as well.

[bigcat1969]

I'm not sure if he can add to to Sam's knowledge, but you might try contacting D Smolken on the KVR or VI forums. He's put out some interesting SFZ stuff and he's a really nice guy. He might have some advice especially about more exotic tricks, hes made synth things out of analogue samples for instance and GUIs.