On Thu, Dec 13, 2007 at 02:19:15PM -0000, Keith French wrote:
> What does the use of the single ampersand (&) do in the last part of the
> filter:-
>
> frame.number & 1
>
> I can't find this documented, only the && for AND?
It will take the value of frame.number and *bitwise* "and" this value
with the value "1".
So, the result would be:
frame 1 (00000001) & 1 (00000001) -> 1
frame 2 (00000010) & 1 (00000001) -> 0
frame 3 (00000011) & 1 (00000001) -> 1
etc.
The value 0 is considered as FALSE and the value 1 as TRUE.
It can also be written as "frame.number & 1 == 1" which is a little
more verbose and intuitive, but then again, it takes more keystrokes ;-)
Cheers,
Sake