In particular, I would like to be able to get away with using the value 3 in the BitDepth field to mean ARGB32 (as opposed to RGB32 with the high byte ignored).

This changes the meaning of the field from something that you can (perhaps foolishly) add 2 to, and get the bytes per pixel, over to something else. That something else is probably a 32 bit packed encoding (like Windows GDI+ has), which includes information about color encoding, memory layout of components, and the like.

I have discovered that there is a wide variety of responses to various "fuzz" conditions for plugins, such as out-of-range parameter numbers, capability codes, handling concurrent parameter changes whilst processing a frame, etc. Some plugins take it all in stride, others fail a little or a lot.

This state of affairs suggests that a meta-data standard might be in order. It could be used to capture the semantics of parameters, determine how much time something takes "a priori", cope with bugs and versionitis, and deal with the fact that people are already extending Freeframe in order to cope with some of the problems it has.

== Jamie