[linux-audio-dev] Olypus voice recorder - codec?

Hi folks. This message does get into driver specifics to an extent, but I'm mostly coming to list for advice on how to find what "mystery codec" is being used. I've been putting some of the tiny bit of actual freetime I get during this winter holiday :), into trying to get a libusb-based driver going for my little Olympus VN480PC. It's a digital voice recorder that comes with a USB cable for transferring voice recordings to a computer, and the accompanying software is windows only. I'd very much like to be able to do this transfer using linux instead of needing windows though. I think I -might- have the protocol mostly figured using a USB sniffer on the windows side, but that may prove to be the easy part of this project. :-S What I'm faced with now, is I have 10K of data which I'm assuming just about has to be the voice data in some format or other - but it isn't clear what format it's in. Toward trying to figure out the format, I've: 1) Computed the difference in the lengths of the apparently-voice data transferred via USB, and the "data" section of the resulting .wav file. They do not differ by a constant - so it's not just a matter of tacking on a header. 2) Computed the quotient of the lengths of the apparently-voice data transferred via USB, and the "data" section of the resulting .wav file. They do not differ by a constant factor - so it's not just a matter of converting, for example, shorts to reals again and again, for example, in which case the lengths, I would think, should differ by a constant factor of 2. 3) Symlinked a file containing the data transferred via USB, to all of the file extensions known to sox, and attempted to use sox to convert those files to .wav. None of the conversions succeeded. 4) Wrote a small python program to treat the data transferred via USB as data to be stuffed into the "data" section of a .wav file, and created a series of .wav files with all format types from 0 to 999. sndfile-info did not give errors for 9 of these, but none of them look or sound right in gnusound. 5) Googled about olympus and voice/audio codecs, to see if there is a proprietary one they favor. It appears they were involved in the design of the "DSS" format. 6) Downloaded "DSS Player Lite" from Olympus' web site, and copied the data transferred via USB to "hi.dss". However, DSS Player Lite did not recognize the file format. Does anyone have any thoughts about what else I might try to see what format this data is in, and/or convert it to a known format? I've got detailed documentation of most of what I've done so far on this project at http://dcs.nac.uci.edu/~strombrg/VN480PC/ The page includes some .wav's, a binary file I'm assuming is voice data in a mystery codec, full USB sniffer logs, and so on. Does anyone have any suggestions - especially toward how to convert that "likely voice data" in the USB Sniff to some sort of known and supported-on-linux codec? Thanks!