[maemo-developers] [maemo-developers] Unresolved issues (Week 46)

[From: Ralph Giles]

On Wed, Nov 22, 2006 at 01:47:45PM -0600, Ed Okerson wrote:

> The iLBC implementation on the DSP is closed source, but is bitstream
> compatible with the one on ilbcfreeware.org.

Since people seem confused: iLBC is a semi-proprietary voice codec. The 
design is documented as RFC 3951, and a reference implementation is 
available under their own license. As I understand the terms, you're 
free to use and hack the reference implementation for personal non-
commercial use. Commercial use and distribution is allowed if the 
implementation is compatible with the published standard, and if you 
notify Global IP Sound (the authors) about it. As such, this license is 
incompatible with Free Software use.

The license on the reference implementation covers both copyright and 
patent monopolies. Copyright can of course been worked around by doing a 
from-scratch implementation from the RFC. Global IP Sound has filed a 
pledge with the IETF to grant a royalty-free patent license to such 
(conforming) implementations. They don't says if the terms would be
compatible with Free Software, so one would have to try and see.

http://www.ietf.org/ietf/IPR/global-ip-ipr-draft-ietf-avt-ilbc-codec.txt
http://www.ietf.org/ietf/IPR/GLOBAL-IP-ANDERSON.txt

So, it cannot be extended without cooperation from the patent holders; 
a free software or open source implementation might or might not be 
possible depending on their interest. But as non-free software goes,
it's not too bad.

If you want something free, I'd suggest using our speex codec, which 
is technically comparable, completely open, and has no known patent 
issues. We don't have an omap dsp implementation, but it has been ported 
to the various TI DSPs.

http://speex.org/

 -r