But, practically speaking, Opus has extremely good guarantees for being unencumbered, as much as is possible - the people working on it have given licenses to use it, and experts in the field have had a while to go over this stuff. Nothing is 100%, but this is as good as it gets.
The whole point of "tested by the courts" is that it's already gone through the appeals process. As in, you have the final decision you're going to get out of the courts.
But this doesn't mean that something can't be designed in a way which avoids all known, and much unknown risk, and licensed in a way which makes frivolous attack less likely.
The obsessives here somes forget that when we talk about comparing things what matters is the relative merits. The commercial codes are absolutely and uncertainly encumbered. And the commercial codec providers have generally had a poor track record of creating codecs unencumbered by third party rights (mostly because they don't make an effort to: they erroneously assume the regular royalties will satisfy all comers). Opus doesn't have these issues and even compared to most software an effort was made to avoid infringement, but nothing can escape the impossibility of absolute certainty under the current patent system.
I know my position causes a lot of cognitive dissonance with people, because it implies that the system is fundamentally unfair. Well, you can either take the red or the blue pill.
Who said you were wrong? Quite the opposite, I strongly agreed with you - anything can be encumbered, and anything includes this.
But the point is that Opus is as safe as you can possibly be from being patent encumbered. Everything is potentially encumbered, but there are things with higher or lower likelihoods. And there isn't any lower than Opus. If this is still too worrying for you to use, then you can't use any software at all.
And in most those cases people were not making a special effort to avoid being effectively encumbered, while Opus was.
Particularly as you naively think that an expired patent is enough to protect you from the system.
Note that I said with respect to...
Algorithms are already implemented and software which uses them is distributed broadly. Where are their court cases? Until those patent trolls (trolls as in spreading FUD) actually show what those patents are, they can't say that anything is encumbered. And they themselves have no idea about what they are. So whatever lies they spread now, even if it comes from Jobs, is simply irrelevant.
There are far more interesting and HN-worthy things to discuss than the non-Opus-specific fact that the patent system is broken, like its potential applications in WebRTC, the hybrid design that merges Celt and Silk, the fact that having a conversation with someone 50 feet away using Opus can have lower latency than just shouting at them (as demonstrated by Mumble's use of Celt beating the speed of sound down a hallway), etc.
"All video codecs are covered by patents," Jobs wrote from his iPad. "A patent pool is being assembled to go after Theora and other 'open source' codecs now. Unfortunately, just because something is open source, it doesn’t mean or guarantee that it doesn’t infringe on others patents. An open standard is different from being royalty free or open source."
You can bet that if Theora ever got traction and seriously interrupted MPLA's revenue stream, there would be suits. Before that time it'd be pointless for them to sue.
Opus is another story, since Qualcomm and Huawei listed supposedly violated patents, so Opus creators were able to review them and to confirm that those claims are bogus.