SonotaCo.JP

[Lightningwizard]

Hi SonotaCo,

We use the detection sound of UFOCapture v2.24 to trigger a high-speed camera. Several sprites were captured like this already. The usual delay between trigger arrival and the event in the high-speed images is 75-200 ms. But occasionally the trigger seems too late, with the event happening before the start of the high-speed video, about 500 ms delay. I suppose such delays can occur because of lag in Windows actions. But could it also depend on the nature of the event itself in UFOCapture, e.g. if more than 1 frame is over the detection threshold could it delay the sound signal because of slow object analysis?

best regards,
Oscar

[SonotaCo]

Hi Oscar
Slow object analysis is a heavy load option.
Especially its rectangle display(SO check box) consumes process time very much.
So they should be off if any performance problem is serious.
If total process time exceed the frame period, frame drop or mismatch of sound can happen.

But...to say the truth, I don't have enough knowledge about Windows task dispatching mechanism.
Also DirectShow subsystem seems to have own frame task dispatching mechanism.
Sound and video are independently processed. Application cannot control them.
So I am thinking any delay can happen for application level tasks.
SonotaCo

[Lightningwizard]

Thanks for your insights. I have turned off the slow object mask now. It can be acceptable at this location because there are not many airplanes and for insects/bats the mask is not so effective anyway because they are not flying slow enough
Curious to see if the timing improves...