Re: repeat post: xcam frontend for SANE

becka@sunserver1.rz.uni-duesseldorf.de
Tue, 28 Jan 1997 16:39:30 +0100 (MET)

> Finally, I found that the "first_frame" field in the parameter
> structure to be rather useless. I'd much prefer to have a
> "last_frame" field that tells you when the last frame in an image
> arrived. Anybody have any objections to this? I can think of a
> reason to want "first_frame" (since it will always be true for the
> first frame after sane_start), but "last_frame" would be extremely
> handy (e.g., xcam would decode/buffer frames until it hits the
> last_frame, and then actually render the collected image).

Maybe the "first_frame" bit gets read a bit more "in the right place", i.e.
_before_ starting to read the _first_ channel of the next image instead of
_before_ starting to read the _last_ channel of the next image.

What I mean is if F mean the time, when the *_frame var is read :

first_frame: F RR GG BB F RR GG BB F ...
|-+------+ |-+------+ |-+--

last _frame: RR GG L BB RR GG L BB RR
+-----|--+ +-----|--+

Actually "first frame" should be interpreted as "finish processing the last
frame and prepare for a new one".

CU,Andy

-- 
==============================================================================
Andreas Beck              |  Email :  <becka@sunserver1.rz.uni-duesseldorf.de>



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