I'm afraid the existing body of software patents dictates not placing such ideas in the public domain, but rather as a form of "patent left" foundation that can force cross licensing access.
It would work for future patents, but I'm afraid it wouldn't work for future software -- the theory being that any non-trivial software will likely infringe on any number of patents. A collection of patents might help force cross-licensing, and so protect new (Free or not) software against existing patents (the assumption being that also holders of non-trivial software patents develop new software, and might infringe on one or more patents in the collection).
I think because everyone is free to extend the public domain via patents. So a researcher at Panasonic or Bosch could tweak something in the codec corpus and patent the tweak.
