[FFmpeg-devel] [PATCH] lavu/eval: add ifzero() and ifnonzero() expression

[Reimar Döffinger]

On Sun, Jan 15, 2012 at 11:08:55PM +0100, Stefano Sabatini wrote:
> They allow to implement the if/then/else logic, which cannot be
> implemented otherwise.
> 
> For example the expression:
> A*B + not(A)*C
> 
> always evaluates to NaN if B is NaN, even in the case where A is 0.

Hmm. I guess we have no way to do that, bur casting to int would usually
result in the NaN becoming 0.
When and why is NaN a problem?