Perhaps you would reconsider having JACK use constant
(frames)
callbacks?
we debated the concept of non-constant callback sizes on jackit-dev,
and there seemed to be strong support for using a constant value.
this doesn't necessarily preclude process() being called with *less*
than the "expected" size, but the current API docs/notes say that its
always constant size.
i don't know what people's thoughts are on "constant or less than the
constant" for the callback. i imagine it will push complexity out into
any clients that do FFT and other similar transforms.
--p