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Recording usb camera (IMAQdx) to AVI

Does anyone else have any ideas as to why the AVI Write would slow down my VI?

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Message 21 of 27
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@Ryan

 

Can you put an error in the loop after the Write AVI and tell me if you have any errors coming out?

 

 

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Message 22 of 27
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I added error handling in, but I haven't seen any errors thrown anywhere, including by AVI Write. I've attached the modified version of your code that I've been working with for reference.

How long of a video do you need? If AVI write is the boottleneck, can you buffer into system memory and then write to file later?

Ryan K.
Product Manager, ATCA and BEEcube
National Instruments
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Message 23 of 27
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The time will vary.

 

I tried to reduce the resolution of the capture from what I had originally (1920x1080) to (1024x768) and now it works. 

 

Is this a memory issue? USB issue?  why can't I record at the full resolution at the specified rate?  

 

I am able to use standard video recording software and it records just fine.  Why can't I do it in LabVIEW?

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Message 24 of 27
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As I mentioned earlier, I haven't seen any memory or performance issues on my system in LabVIEW 2015 32-bit, so I don't think it's a memory issue. I also don't think it's a USB issue since the no recording version of the VI works without issue - I'd expect to see the bottleneck there as well if this was a bus problem.

Reducing the resolution reduces the amount of data that needs to be written to disk, so given that a lower resolution (less data) works better, it still makes me think there's some bottleneck somewhere in your system (hardware, OS, or something else) that's liminting your disk write speeds. Given that it runs fine on my machine, it doesn't look like it's something inherent to LabVIEW on it's own, but I suppose it could be some combination of the efficiency of the LabVIEW/the AVI Write file + your computer's hardware setup.

Is the 3rd party software you mentioned using the same AVI codec? What software are you using? Are all of the other write parameters the same? Without knowing more about how that software might be performing it's write, it's hard to speculate as to why it may be working more efficiently than the LabVIEW write.

Ryan K.
Product Manager, ATCA and BEEcube
National Instruments
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Message 25 of 27
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I'm using a program called AMcap, it looks like it is using no compression and works with the 30fps.  I'll try using no compression on Labview, if that's even possible.

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Message 26 of 27
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use this vi it is point that i told you before 
check two method for recording
for method one you have to change fps rate of recording based of fps or capturing 

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Message 27 of 27
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