[Freeswitch-users] A patent list for codecs

[Steve Underwood]

Hi all,

There is an issue which is common ground for most free telephony 
projects - codec patents. In the near term we need to live within the 
constraints of these patents, but they won't last forever (well, not as 
long as Disney isn't a big patent holder). The snag is working out when 
they will be free. There are several relevant encumbered speech codecs, 
potentially useful for what we do. The obvious ones are AMR-NB, AMR-WB, 
G.722.1, G.722.2 (which is basically AMR-WB by another name), G.723.1, 
G.728, G.729, G.729.1. If you look through the ETSI and ITU web sites 
you can find some material about who claims patents related to these 
codecs. However, the information is far from complete. In most cases the 
actual patent numbers claimed to be relevant are not listed. The dates 
of filing, granting and expiration are not generally listed, though if 
the patent numbers are available the dates are easy to find.

I think it would be valuable to start a web page where all this 
information is gathered. We might then get a real picture of when a 
codec will become unencumbered.

Clearly, video and even image, codecs are also of relevance to us. 
However, I think the speech codecs would be a good starting point.

Steve