imaq

[Faquim]

hello!

well, i am trying to to make a VI that simplys captures a video from a video camera and saves in a folder, that i create programatically.

But i am noticing that when i run the video saved, only the half of the video that was shot is actually being played.

I figured it out that maybe the while loop used to capture and save the video maybe is slower than the frame ratio of the camera so maybe for each loop the camera sends 2 pics for the labview and it only shows one, it only saves one.

Any ideas on how to fix that? 

Any help is appreciated 😄

I am attaching the VI 

[udka]

Hi Faquim,
Please check this link for capturing video.
https://decibel.ni.com/content/docs/DOC-3587

[Faquim]

udka, looks like it, exactly what I needed to know.

I dont have the PC now, ill work on testing it monday.

Thank you a lot, for your time and help!

[Faquim]

Hello again,

well the VI worked pretty well but looks like this works on getting a certain number of images and then they make a sequence with that at the FPS i specify.

So lets say i set 30 FPS, the video goes much faster than it should.

I could set up the FPS to have the exact time of video saved and there is an excellent point in doing this, looks like i am not missing any images...

Anyways, I tried another way, using the Vision Acquisition VI, I configure it to make a continuous acquisition with inline processing and then i can configure the camera. I tested with the webcam of my pc and in first execution I had the same old problem of missing images. Then I configured to send 60 images to buffers (since lower ratio would make I miss more images I guess), and asked the VI to show me the indicators to know how many missing images I have. For my surprise, I had an error and couldnt execute it (not executable error). I search for it in the web and couldnt find anything related to that.

What am i doing wrong? I read the tutorials about NI-IMAQdx and there is no problem in using the 60 images to buffer...

I am attaching the VI.

Any help appreciated,

Thanks in advance 😄

Att,

[udka]

What error you got? can you post a screenshot of it if possible?

[Faquim]

Ok, I did in 2 ways

Here is a link for the error mesage: http://prntscr.com/2hw7x3

and I am also attaching an image.

Thanks in advance

[udka]

-Did you try lowering the frames and check whether you get the same error or not?
-What camera you are using?
-What is the maximum fps it can give?

[Faquim]

I am using the integrated webcam, which i think can acquire at 30 FPS at max

I just tryed to lower both the number of images sent to buffers to 10 and the FPS of acquisition to 11, and still didnt work.

Then i did another test, lowering the number of images sent to buffers to 3. Still cant run. I read in the tutorials that this number should be 3 or higher, because it risks losing a high number of images...

thanks for your time and help

att

[udka]

May be camera was not closed properly!!!
-Are you able to open camera in MAX? try grab and snap there?
-Restart your PC, if things doesn't work 😛

[Faquim]

yes, I am able to grab or snap in MAX.

Is the problem in the VI, i mean, the closure of the camera?

Ill try restarting the PC, now.

Anyways, ty for your help =]

Att