Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

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procyon12
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Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#1

Post by procyon12 »

Hi Robin,

What does this mean "Remove frame rate drops on QHY174MGPS" ? And will it be also involved into 4.0 ?

Thanks, Christian
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Re: Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#2

Post by admin »

Hi,

Marc at SWRI spotted that there was a consistent problem with two or three frames dropping every second if you were running the frames at high frequency (100fps in this case).

A bit of digging turned out the fact that I had put some synchronisation in the code to stop frames from being fetched from the camera at the same time that SharpCap was updating the thermal information (temperature, cooler power, etc). This was in response to a bug at some point in the QHY SDK that caused crashes if the two were happening at the same time. This synchronisation turned out to be the cause of the missing frames, so I removed it (after testing with the current SDK I couldn't make any crashes happen, so I suspect that QHY may have fixed the underlying bug that I was working around).

Cheers, Robin
procyon12
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Re: Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#3

Post by procyon12 »

Hi Robin,

Thanks, I already suspected this was the reason ...
For us in the stellar occultation community dropped frames are an essential issue. Will the change be in SC 4 too?

Cheers, Christian
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Re: Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#4

Post by admin »

Hi Christian,

yes, in 4.0 too, from next week's update.

If we start spotting any new crashes that might be attributable to removing this synchronisation then I will have to investigate further. The worrying thing is that the crashes might occur still on some models of camera.

Cheers, Robin
procyon12
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Re: Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#5

Post by procyon12 »

Hi Robin,

Could you please state: is it included in the latest v 4 from today ? (it isn't mentioned there).

Thanks, Christian
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Re: Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#6

Post by admin »

Hi Christian,

yes, it is in today's version. Simple check... set up 640x480, MONO8, low USB traffic, 10ms exposures. With the old code you would only get ~96fps. With the new you will get ~99.5

cheers,

Robin
procyon12
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Re: Latest 3.2 (6482) of Mar 11: "Remove frame rate drops on QHY174MGPS" ?

#7

Post by procyon12 »

Many thanks Robin,

A quick tests with latest v 4 and your settings worked :-), this will be checked out deeper.

Christian
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