I literally edit them right in Schism Tracker. Simply load any sample (I recommend importing it as a .wav), give it a loop point divisible by 16 (I literally type in the number. A calculator can give you a quick check for whether or not you picked a loop point divisible by 16.), and if you have the loop point divisible by more than 16 (32, 64, 128, 256, and so on...), then cut that sample right down to half its size for optimization and room for the other samples that you might use. Of course, for non-looping samples, sometimes I just cut them right down to a power of two, or somewhere in between.
Basically, it's pretty simple to get yourself a good BRR sample (at least without directly converting them... that's where the various tools come in... I can think of BRRTools, but more specifically, since it has a BRR converter built in, SNESMod. However, SNESMod only takes Impulse Tracker files as an input.)
I don't know what type of sample editors other people are using... but at the very least I hope there's a length indicator in samples. Otherwise... well, it might not come out so pretty if turned into actual SNES samples.
I literally edit them right in Schism Tracker. Simply load any sample (I recommend importing it as a .wav), give it a loop point divisible by 16 (I literally type in the number. A calculator can give you a quick check for whether or not you picked a loop point divisible by 16.), and if you have the loop point divisible by more than 16 (32, 64, 128, 256, and so on...), then cut that sample right down to half its size for optimization and room for the other samples that you might use. Of course, for non-looping samples, sometimes I just cut them right down to a power of two, or somewhere in between. :D Basically, it's pretty simple to get yourself a good BRR sample (at least without directly converting them... that's where the various tools come in... I can think of BRRTools, but more specifically, since it has a BRR converter built in, SNESMod. However, SNESMod only takes Impulse Tracker files as an input.)
I don't know what type of sample editors other people are using... but at the very least I hope there's a length indicator in samples. Otherwise... well, it might not come out so pretty if turned into actual SNES samples. ;)