Hi,
If you don't want package celt 0.5.1 -- fine. You can patch your spice server and client to just not signal the celt capability, and they will interoperate just fine with everybody else using raw uncompressed audio. But IMHO it would be stupid to not support audio compression in your spice packages. That is your call though.It would be stupid if 0.5.1 was the only choice for compression.
Right now it is, although we are looking for other options. It isn't top priority though.
There isn't going to be a Debian release with spice in it for around 2 years now in the best case, so if there isn't another suitable choice available by then, then something worse than this has gone badly wrong.
Two years should be enough time, maybe we even have celt (or its successor) with a stable bitstream format by then.
Why not just let systems negotiate the best codec they both know?
Will surely happen as soon as we'll have more than one codec ;) cheers, Gerd