What makes you think that the moment is "arbitrary"?
By your definition.
Anyway, for the smooth video stream to be shown in the EVF, you must start the captures in regular intervals and you must provide the rendered buffer to the EVF in regular intervals, namely 1/30s if your goal is 30fps.
Here Cn is the beginning of frame captures (exposures), On is readout and output to the raw buffer, Pn is the
end of processing and Rn... are moments we refresh the rendered buffer for the EVF. Normally it's done via two alternating buffers, and you just switch the buffer, so R's are instantaneous.
Code:
Fig.1
C1-O1------C2-O2------C3-O3------C4-O4------C5-O5------C6-O6
------P1---------P2---------P3---------P4---------P5--------
--------R1---------R2---------R3---------R4---------R5------
It's obvious that no matter what parallel processing you use, there will be some gap between any Cn and Rn, determined by the time between Cn and On plus Pn.
Now you can offset the timeline with Rn but the distance between any Rn and Rn+1 will be
fixed. If processing takes too long
and the h/w architecture allows that, you can have an overlap of processing with captures:
Code:
Fig.2
C1-O1------C2-O2------C3-O3------C4-O4------C5-O5------C6-O6
P0---------P1---------P2---------P3---------P4---------P5---
--R0---------R1---------R2---------R3---------R4---------R5-
Still each Rn must finish before On+1.
Also, you can't have more than 1/30s between any Pn and Pn+1 (if that happens, you skip the frame). Bear in mind Pn in these diagrams is the end of processing, not the whole thing. The beginning of n-th processing is right after On.
So in this simple case the processing time (Pn - On) is also < 1/30s.
Now we've already discussed the possibility for (Pn - On) to be > 1/30s, in case there's some parallel processing.
Code:
Fig.3
C1-O1------C2-O2------C3-O3------C4-O4------C5-O5------C6-O6
-----------------P1--------------------P3-------------------
------P0--------------------P2--------------------P4--------
--------R0---------R1---------R2---------R3---------R4------
But as I explained in a couple of previous messages,
I don't think it's happening. But I don't know for sure.
You obviously don't understand how a pipeline works.
My primary work is data processing, multithreading, rendering etc., I think I do understand how
a pipeline may work on a high level.
But no, I don't know how
the Canon pipeline in cameras work exactly. I guess you don't know it either unless you work at Canon.
www.the-digital-picture.com
