(if you are note exited by freeing sampled instruments but only by the technical aspect skip to the line "But back to the topic:")
I am doing a research and mail marathon right now. Again I am searching for more or less open source and free samples but this time I decided to browse more "free things" website archives.
So far I found a handful of, more or less useful and nice, instruments or "noise" packs with a good license.
Even better is that I try to contact as many instrument developers as possible per mail, asking them to release their already free-of-cost instrument under a more open license. Or if the license may be open alreaday but is unclear (sample licenses can be quite confusing if you press them into the Creative Commons frame) I asked for clarification.
Surprisingly already several people answered which resulted in the freedom of some packs and, best of all, the producer with one of the closest and permissive statements (but otherwise very good) of all contacted me very quickly and said they want their free instruments as open as possible and the closed licenses were a misunderstanding, only for their fully commercial instruments.
I'll release a list with download links on my blog nilsgey.de in the near future. If the linux audio community has enough webspace we could even mirror most of them. Part of my mails is always the permission to redistribute and mirror download. You don't believe how many say "do what you want with these samples, but you are only allowed to download them exactly here. If tommorow this website will be gone there is no legal way to get the samples anymore"
But back to the topic:
Sadly many of those instruments are in .nki or .nk* format which is the Kontakt Player or Kontakt Something Fullversion format.
The wave samples are (often? by design?) there as plain files, but it is hard work to guess how they should be arranged and what is needed. As far as I know the kontakt format has more features, such as scripting, than sfz, which is currently the "Linux sample flagship". I hope I am wrong here.
I know there are sample converter programs (for Windows) like Chicken Translator or the "W. Grabowski Extreme Sample Converter". I have used them and even simple conversions like sf2 to gig, or gig to sfz were always a bit odd or plain wrong. They have menu entries for Kontakt and EXS24 (the Apple Logic Sampler format, you see that quite often as well) but I don't believe that will actually produce accurate conversions.
Is there someone who knows more about these formats? Even if it is not possible to write a sampler engine (it would not be the first [partly]binary, closed format loaded by open source software) maybe there is at least a way to get all the needed information to convert/correct them by hand or individual scripts.
For the more pragmatical, non-100%-idealist people, that would be a major step in general Linux Audio mainstream direction. For the last years and currently many instruments are samples which seem to be interpreted data (I hope I am not wrong here). This is not the windows-VST problem but actually solvable without recompiling and re-releasing even the major commercial instruments.
P.S. I got some packs which are just wave files or the nki files seem to trigger just one-shot samples. I thought about creating .sfz files for them. Any help would be welcome. I already have a github repository up with two projects (WIP), so contact me here per mail or IRC #lad if you are interested.
Linux-audio-dev mailing list