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Reducing SeqGrabber overhead

Hey all,

I've gotten some help from users of this list trying to get my DDR software
up to speed. For design issues, I'm stuck for the time being with
cooperative threads. Because of this, my serial communication thread has to
wait the entire duration of a call to SGidle. I've found this acceptable
when previewing video, but lag times swell during recording to disk. I've
seen periodic calls to SGidle take as much as 135ms. I'm looking for ways
to get these as low as possible. Almost all occur in the range of 12-15ms,
which is acceptable, its merely these spikes I'm worried about.

Right now my code is very simple. I open a seqgrabber component, set my
gworld to the previewwindow using SGsetGworld. I make sure my channel
bounds are set to the source video bounds. I have play during preview
turned off in channel usage (both video and audio). And then I call
SGPreview. For capture I call SGSetDataOutput with the seqgrabtodisk flag
set and SGrecord. I have a separate thread which just calls SGIdle in a
loop.

If there is any way I can speed this up, or perhaps take writing the file to
disk into my own hands such that calls in the thread now calling Sgidle
could be more granular (so I could sprinkle them with YieldTothread calls).

QT is still new to me, and any help would be appreciated,
mike
--
Mike Woodworth
divergent media,inc.
email@hidden
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