Hello,
Thanks for the clarification.
There's nothing wrong with posting the same message to a number of similar forums, but it may be considered helpful to indicate this fact so that anyone wishing to help/advise you might watch the other places as well.
I have no detail on that the .XMI files might be, and no-one else seems sure either. I would suspect that they may contail supporting information for the midi, or they may replace the midi totally, but either way, I'd guess that the .XMI files could be totally machine dependant, and therefore nothing to do with midi in any way. Someone on the HR forum wonders if they are files relating to specific DAW systems, this sounds a reasonable guess, but anyway, they must be NOT midi, even if they have been generated from (?) midi data.
Your references to Sound Canvas are strange, as SC is in effect midi, just with various extensions which can be controlled by normal midi, or via SYSEX instructions that can be included within a normal midi file. No need for anything regarding .XMI, un less of course the composer needs to go off way above normal midi and even SC facilities again, in which case, again, the original midi becomes irrelevant?
If you hope to do anything with the .XMI files, which you may well NEED to do to get anything like the 'correct' sound, then you'll need to know what system was used tp process/interpret the data in the .XMI (which DAW or whatever), and again, you will need to know the precise (or compatible) hardware that was used to convert the data into audio sound.
Your reference to FLAC is again confusing, as FLAC is a digital format which is nothing at all to do with midi, or Sound Canvas, or anything like that. There is no way to convert between midi etc and FLAC - well, no 'practical' way. If you've got the audio you want coming out of something, then you could record that in one of the digital formats, which could be FLAC (or WAV, or MP?, or whatever you prefer).
I am familiar with some of the work that has been done regarding the Sierra On Line games, using the composing skills of a number of people (some some by Jan Hammer for example). There is a project to save all this music. People have extracted all the music from many of these games, and it is available as digital, midi (usually MT32 devices, but others as well, incl some SC I think). This data in midi form includes a lot of SYSEX data, for new 'sounds', but especially for sound effects, and a lot of pretty unique work was done at the time which is well worth preserving, but IDEALLY you do need access to the correct 'devices'. I'm OK here, as one of my old PCs has a Roland LAPC-I card which is MT32 compatible, so I can handle the original SYSEX.
Geoff