Although Speex tries to avoid using patented algorithms,
we cannot provide any warranty that Speex is indeed completely patent-free.
This is because the whole field of speech coding is a real patent minefield,
with the scope of many patent still unclear. Also, each country has its own
patent laws and list of granted patents so tracking them all would be next
to impossible.
That being said, we are doing our best to keep away from known patents and
we do not patent the algorithms we use. That's about all we can do about
it. If you are aware of a patent issue with Speex, please
let us know.
For the reasons explained above, we strongly suggest that you have a closer
look at patent issues with respect to your country if you are thinking about
using Speex commercially. Note that this is not specific to Speex, since
many "standard" codecs have an unclear patent status (like
MP3,
GSM and probably
others), not to mention the risks of a patent holder claiming rights on a
standardized codec long after standardization.