History
Every DAW has turned out to need it's own sampler, and Pro Tools / Digidesign are no exceptions. Structure was released in 2009 as a RTAS-only sampler with quite an array of features.

The story of Structure is really quite fascinating. Originally it was the internal project of Peter Gorges, originally of Steinberg and Wizzo, and Hans Zimmer. Zimmer had a corporate relationship with Steinberg at the time, so he and Peter got together to make a super sampler of sorts that Hans could use.0

Where that went is unknown to us, but eventually Gorges went on to make Wizzo his own separated company, then sold Wizzo to AVID (Digidesign). Wizzo made mainly sounds, but also some software, and the pre-Structure was apparently included in the assets. The selling of Wizzo was really a name change for Gorge's company - it them because the A.I.R. division of AVID, A.I.R. standing for Advanced Instrument Research.

(Just to sew up the Zimmer connection, we have seen at least one other Zimmer internally-designed sampler, a 64-bit monster that had a lot of good ideas too, it was called SAM. It never saw the light of day either, but it looked fascinating.)

Apparently Gorges pulled the Structure (if that's what it was called at the time) up and finished it for A.I.R., and it became Structure.

Structure was released in 3 versions; Structure Pro, Structure LE, and Structure Free. All were divided by mostly voice ability, and also Free did not let you make your own instruments, but it would load any Structure file available.

Structure only works as a RTAS plugin for Pro Tools, and it heavily sports a database engine combined with strong sample-playback features and scores of effects that you can integrate in easily on the instrument level. The interface is beautiful but a little slow and cumbersome.

Structure really took off when it was first released, and AVID/Digidesign seemed to take quite an interest in it and supported it strongly. However, for whatever reason, support fell off quite suddenly, with no new releases or sound libraries coming in to bolster it. Nowadays it seems abandoned with few people talking about it anymore. Some of the appeal of Structure was good RTAS reliability, as plugins like Kontakt did not fare too well in the RTAS environment. Now that Kontakt (and other samplers) have their RTAS chops down, the need for Structure seemed less over time.

Synthesis and File Structure
Structure uses .patch files to store an Instrument. This can be a small control files handling WAVE or AIFF files (like EXS or Kontakt), but also monolith files too. (Interestingly the factory library uses another type of large monolith files per Instrument called .big files - these are encrypted and cannot be converted from. These are not the same as monolith files a user can save.)

Structure also uses .part files that make up sections of what a .patch file can hold (just like Kontakt's Group files.). A Structure Part is the same as a Kontakt or EXS24 Group.

Similar to EXS24, Structure holds quite a bit of information about the sample file in the .patch file itself. Again, the disadvantage of this is that it's easy to screw up the playback by editing the sample and not having it updated properly.

Structure has a absolutely impressive set of effects that can be used with any Part, and they are quite good.

Translating and Building Structure Programs

An Structure .patch file is just a single Instrument, so any conversion creates a single .patch file per incoming program. Sample files are selectable between WAVE and AIFF.

Since Structure supports keyswitching, controller-switching, release-triggering, and even round-robin, it accepts all these from incoming formats.

Structure accepts incoming Group structures and divides them up as Parts if the Structure Group to incoming Groups parameter is checked.

Structure has a series of real-time knobs on the front of the interface designed for real-time modification; what these knobs can do and how they are set can be set up under Format Preferences-Digidesign.

Translating Out of Structure Format

This is not a complicated procedure, although it can be if you are using Rule/Dimension-based features and the destination does not, or if your Structure file is using lots of samples and you will overrun your destination's memory capacity.

You can translate any Structure file, monolith or referenced, EXCEPT FOR the factory library .big files.

Part names are also preserved; any destination will recognize these if their Group to incoming Groups parameter is checked.

Translator assumes the links from a Structure file are correct; if it can't find the external sample file, Translator will ask you where it is, either via the File dialog or Folder dialog. Using the Folder dialog (Create Catalog), choosing a folder will provide a hint for remaining unfound samples. On the Mac, Translator will also perform a quick CatSearch to find the sample as well.

It is also possible, if the destination format permits it, to just assume the sample is where it actually isn't and the new format will just pass that path. Checking Do Not Require Samples in Preferences-Fix References allows for this; please note the extra parameters you can fill in.

History
SampleCell was a computer card concept with a powerful sampler engine on it. Developed by digidesign of ProTools fame, it was primarily available for Macintosh, although an Windows NT version was made. (This was strange since it is very rare to see an item made for NT only and not the normal Win95/98 platforms. As a result the Windows version were not very popular, so SampleCell is really regarded as a Mac device.)

SampleCell I was first developed around the late '80's, then SampleCell II came quickly after that. SampleCell II improved on a couple issues but wasn't completely revolutionary. Translator only supports translating into SampleCell II, which isn't a big deal since that's what pretty much everything is.

Many sound libraries were developed for SampleCell - usually not in original native form, but as ports from popular sound libraries. Many professionals who used ProTools wound up including a SampleCell card in their systems, and since their voices are heard within the music equipment industry, many sound disks were made available in SampleCell file format.

SampleCell made the transition into pure-software; Soft SampleCell was been released having no sound card prerequisite. It was OS9 only and worked just like the older SampleCell. However, interest waned and Soft SampleCell was discontinued before an OSX version could be released. (A little known fact is that an OSX version was made by the original author (one guy), but was rebuffed by Digidesign.)

One little twist to the popularity of SampleCell - although the Alesis QS-series of synthesizers were always regarded as closed-system playback synthesizers, they could, via a Mac or Windows program called SoundBridge, load in a SampleCell Instrument. This was definitely doable given the correct programming systems, but they really never appeared ont he scene at the time. Still, some people have been known to use the feature.

Synthesis and File Structure
SampleCell stored its sounds on regular Mac or DOS disk systems, although it's sample referencing was a little strange but yet advanced. For each sample reference, the Mac's Volume Name, the Sample file name, the FileType, and the DirID number are stored. This could effectively find a sample on a HFS disk, since folders are marked with ID numbers to distinguish them. The big problem was if you moved the contents off the disk.

The main Instrument unit is called an Instrument, and that contains KeyGroups that reference Samples. Mono and Stereo samples are supported, although an Instrument can only have Stereo OR Mono samples, not both. Also, the sounds can be AIFF, Sound Designer I or II, Mac Sound Files, or WAV; and they could be mixed within a single SC Instrument. The limitation of a SampleCell Instrument is that is only one KeyMap; although you could have up to 6 velocity splits on a MIDI-note, there is no allowance for layering of sounds within an Instrument. To allow layering, another file type is supported, called a Bank. This is really a macro which loads in one or more Instruments, thus allowing layering of sounds, since it allows more than one instrument on one MIDI Channel.

Going back to sampler referencing and finding it's samples, SampleCell was exceptionally problematic with this for a couple of reasons (although SampleCell worked fine). It was just a part of Mac culture in the '80's and '90's to name things funny - with non-standard characters, with leading or trailing spaces, and with heavy reliance on FileTyping of sample files and not using extensions like .wav or .aif. Additionally, since Digidesign developed Sound Designer, SampleCell instruments used SD1 and SD2 files, which use the now deprecated resource fork concept of HFS disks, and that complicates matters since many modern samplers do not use these formats, and also resource-fork dependant files do lousy when it comes to moving them from disk to disk.

Basically SampleCell was developed in a time where the Mac culture was isolated and only had to depend on itself and other items that existed in its time. As those technologies drifted to the wayside, SampleCell became that much more irrelevant.

Besides all that, SampleCell is fairly powerful as far as programming goes. There are 3 ADSR envelopes, one for Pitch, Filter, and Amplitude respectively. There is a Filter, with Cutoff and Resonance adjustments. SoftSampleCell gives you a choice between 2-pole and 4-pole varieties (no high-pass filter, sorry). There are a fair amount of modulators, along with a curve making feature called Trackers.

One can really tip the hat to SampleCell, arguably it was the most ahead of its time platform that ever existed.

Translating and Building to SampleCell Format

An SampleCell Instrument file (.ins) is just a single Instrument, so any conversion creates a single .ins file per incoming program. SampleCell also has a Bank concept (.bnk files), so incoming Banks create a .bnk file as well as .ins files for every Instrument. Although SampleCell supports all types of older sample file formats, the Conversion Engine only allows WAVE and AIFF files to be created and used.

Since SampleCell doesn't use paths to find it's samples (it uses the Volume name and the DirID number that HFS uses), if you select a different folder than the Program Folder to write newly created samples, whatever you use to load these new SampleCell Instruments will likely not find the samples. Because of that, we strongly recommend writing them to the same folder as the new Instrument/Bank (.ins/.bnk) files. If you are converting from WAVE/AIFF-based formats, you will need to select Copy Samples to create new samples for this purpose.

SampleCell uses the same 'TopKey' key range paradigm as Korg instruments. This means that and gaps in the key range - plus the leading and trailing areas - need a 'silent' or a NULL sample. If a gap is needed, the Conversion Engine will write a 'blank.wav' file with no data in it, in order to assign to those gaps. If only leading / trailing areas are needed (almost always the case), the Conversion Engine will always setting the lowest area as starting with MIDI 0 and the highest area as MIDI 127.

SampleCell is like EXS24 in that it it's envelopes, LFO's, and modulators are global to the Instrument and not per-sample. It also only supports up to 6 velocity splits. Keep that in mind when you are converting into it; the Conversion Engine will make it's best compromises and reduce the splits to 6 if you are contributing more.

Translating Out of SampleCell Format

There are two methods available for converting SampleCell disks and objects.

From File
This is just the same as converting any instrument file such as .exs, .nki, et al. But keep in mind that Translator has no idea of where the samples are since the the SampleCell file doesn't point to it in a modern way. Translator will attempt a full disk search (if on Mac) and if it can't find it, it will ask you where they are. Typically, a single request and a pointing to the main SampleCell sampler folder for that library will do the trick for the entire set of SampleCell Banks and Instruments.

Regarding full disk searches on Mac (called CatSearch), many SampleCell CD's were early HFS designs that resist the modern OSX CatSearch, all of this is transparent to you. If a CatSearch cannot be accomplished, it just fails silently.

From Disk
When Translator was Windows only, over 10 years ago, we wanted to convert SampleCell format. So we had the idea to treat HFS CD's as a proprietary disk format, just like an Akai or Ensoniq or the like. Windows does not recognize HFS disks, but we developed the technology that we could.

So any HFS CD comes up in Translator as a proprietary disk under Proprietary Drives. You then can scan the CD looking for files. and you can convert off that. The distinct advantage of this is that it's designed to find the samples in a much more natural way, it takes those off the disks and does the conversions under the hood. This avoids all the nasty naming issues, resource fork junk, and obscure sample formats a SampleCell instrument can use (they even use System 7 sounds SFIL) and simply retrieves the samples in AIFF format.

Please remember that although SampleCell uses external sample files, and often they are AIFF files, that most of the time Translator will elect to write new AIFF or WAVE files for destination formats that use WAVE or AIFF files. Most of the time, the sample files are poorly named or don't have extensions, things that make them difficult to work with on modern systems. Translator does you a favor by renaming them, adding the extensions, and writing them more properly.