Contrary to what people at VPIM meetings, lists, and on web pages
have suggested, nobody owns any IPR on the GSM 06.10 vocodec format,
or on any routines for encoding or decoding it. It was developed
from published code by people who took care to publish it before it
could be monopolized.
Philips owns the rights to a related but different form of LPC,
from U.S. patent 5,943,646, which was applied for more than four
years after the publication of GSM 06.10 by ETSI. That patent is
most likely what is confusing people about the status.
Also, http://www.ema.org/vpimdir/specs/draft-ema-vpim-wav-00.txt
-- the pending-in-limbo audio/wav IANA registration -- has an error:
it reads "audio/vnd.wav"; that should be "audio/vnd.wave", which,
by the way, hasn't been registered with IANA either. I agree with
Keith Moore that they should be registered as identical, and I hope
that they be registered in the same document to make that clearer.
The definitive reference for these formats seems to be kept in
Microsoft's Support Knowledge Base Article ID Q120253:
http://support.microsoft.com/support/kb/articles/Q120/2/53.asp
Cheers,
James