Dropped Frames

Discussions, Bug Reports and Issues related to Beta versions of SharpCap
Furgus
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Dropped Frames

#1

Post by Furgus »

Firstly thanks Robin for such a great piece of software, and for your continuing hard work.
An issue has come up for me, though, with dropped frames with 3.2 beta. When pushing my ZWOASI224 to higher frame rates, at any size ROI, then considerably more dropped frames are reported. This occurs whether writing to the external USB 3 hard drive or the internal laptop SSD.
Keeping things exactly the same, I reverted to the last version of 3.1 and saw (as usual) no dropped frames at all in my tests, on the USB 3 drive or the internal SSD. I monitored the CPU and memory in 'Performance' in Task Manager and in both cases they looked relatively unstressed.
Laptop is i5 (quad), 2.4 GHz, 4Gb, W10 Pro, 64bit. I wouldn't normally worry about the odd dropped frame (though its always been virtually perfect before) but I've been doing some occultation timings recently where it could be a problem. Your comments welcome.
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Re: Dropped Frames

#2

Post by admin »

Hi,

please look in the 3.2 log after seeing the dropped frames - there are a number of possible causes and the log should detail information about why the frame has been droppped - feel free to share the entire log here if the interpretation is not clear.

cheers,

Robin
Furgus
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Re: Dropped Frames

#3

Post by Furgus »

Thanks Robin,

Have repeated the runs with the camera...same results.
Here is part of the log from 3.2

:Info: 20:41:31.0324928 Thread:ASI Grab Thread#33 SharpCap.Base.DroppedFrameLogger.Count(DroppedFrameType type, Int32 count) :: Dropped frames : 8 of type ZWOCaptureThread
Info: 20:41:31.0324928 Thread:ASI Grab Thread#33 SharpCap.Base.DroppedFrameLogger.Count(DroppedFrameType type, Int32 count) :: Dropped frames : 11 of type ZWOTimeout
Info: 20:41:31.0324928 Thread:ASI Grab Thread#33 SharpCap.Base.DroppedFrameLogger.Count(DroppedFrameType type, Int32 count) :: Dropped frames : 40 of type ZWOFromSDK
Info: 20:41:31.0324928 Thread:ASI Grab Thread#33 SharpCap.Base.DroppedFrameLogger.Count(DroppedFrameType type, Int32 count) :: Dropped frames : 80 of type PreviousFrameNotProcessed
Info: 20:41:31.0324928 Thread:ASI Grab Thread#33 SharpCap.Base.DroppedFrameLogger.Count(DroppedFrameType type, Int32 count) :: Dropped frames : 6 of type DroppedBeforeTransform

With exactly the same setup in 3.1.... no dropped frames at all. (640x480 ROI, @127 fps)

Both versions run about 20% CPU and 56% memory.
Not sure if this helps!
Rgds
Simon
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Re: Dropped Frames

#4

Post by admin »

Ok, sorry but I'm going to ask for more info

* Camera settings being used (please share a camerasettings file and check they are identical between 3.1 and 3.2)
* Are the problems occurring when capturing only or also when just viewing the image
* Do you have any tools active - for instance histogram etc - that might affect performance differently between the two versions
* It would also be helpful to have full logs from 3.1 and 3.2 to see if there is anything unexpected in either of them
* Are the settings the same in the two versions of SharpCap (particular the memory settings might be relevant here)

thanks,

Robin
Furgus
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Re: Dropped Frames

#5

Post by Furgus »

Thanks Robin.

Have checked camera settings files line by line, they are identical for each run apart from Temperature, TimeStamp values and SharpCap version!
Settings are basically AVI, RAW8, 640x480, 0.27mS, Gain 600. Both recorded to same internal SSD. Binning '2'.
3.1 capture, 30 seconds......3833 frames, 0 dropped. 3.2 capture, 30 seconds.......3729 frames, 95 dropped

The problem does not arise in preview, apart from the odd frame.

Memory settings are the same ('Classic')

Ok....I'm writing this as I confirm each point.....its something to do with the Display Histogram Stretch tool. In 3.2, when capturing, there are hardly any dropped frames when its switched off. If you switch it on again, it starts to drop frames. I switched the tool on and off several times while capturing and it was an obvious effect. I tried it in 3.1....it doesn't matter if you have the tool on or off, or switch it during capturing, there are no dropped frames.
I have now also tried the buttons on the right hand side of the DSH tool....they do seem to affect it somehow (in 3.2), but its unpredictable.

I have also now tried capturing with the binning set to '1'......the problem of dropped frames is the not as bad in 3.2. In 3.1 there are no dropped frames whether binned or not
So maybe there's a pointer there?

Many thanks
Simon
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Re: Dropped Frames

#6

Post by admin »

Hi Simon,

Ok, now I am seeing something like you are seeing - basically the dropped frame count rises during capture on the ZWO174, whereas what should happen is the number of frame memory buffers in use should rise. I will investigate.

cheers,

Robin
Furgus
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Re: Dropped Frames

#7

Post by Furgus »

Hi Robin,

Interesting. Many thanks for looking at this.

All the best
Simon
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Re: Dropped Frames

#8

Post by admin »

Hi,

please try this version

https://d.sharpcap.co.uk/download.html? ... 3.2.5828.0

I am not putting it on the main download page yet as I want to perform more testing to make sure the changes I have made have not broken anything else, but I believe it should fix the capture frame rate issue.

cheers,

Robin
Furgus
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Re: Dropped Frames

#9

Post by Furgus »

No dropped frames at 127 fps (other settings as before, ie 640x480, AVI).
Histogram selection makes no difference (no dropped frames)
No dropped frames writing to external USB3 SSD @ 127fps (binned or unbinned) either.

Runs at very high FPS (smaller ROIs) such as 250 and 450fps started to drop frames, but these must be unrealistic.

Awesome result! No bad effects noticed so far.

Many thanks!

All the best
Simon
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Re: Dropped Frames

#10

Post by admin »

Excellent :)

Robin
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