IMAQ AVI - What is "frame read lookahead"?

Hi,
I'm using The IMAQ AVI Read Frame function, and just wondering what the "frame read lookahead" input actually does. The documentation is very vague.
Thanks

What is vague about it? What additional information do you need?
Mike...
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IMAQ AVI read frame performance

I've been playing around with the read AVI with buffer example in the Developer Community. It reads all the frames of an AVI into memory and then plays them back at the appropriate frame rate. This works ok with very small AVI files but with anything larger it gets slower and slower until it almost stops loading the AVI. At that point it seems to be loading less than 5 frames per second and is killing my cpu. I have plenty of free RAM during this.
https://decibel.ni.com/content/docs/DOC-8479
This is the case with the play AVI example that comes with Labview too (without a buffer) which just loads and plays one frame at a time. Can someone suggest a way to improve the performance of an AVI player in Labview? My ultimate goal is to read an AVI and detect changes in motion of objects by comparing two frames at a time. These AVIs are going to be at least 5 minutes in duration at a frame rate of 30 fps.
I'm using Labview 2009 with the Vision Developer installed.
Attachments:
image_png.png ‏77 KB

VTKim wrote:
Hi,
One thing we could implement is a compression filter that is on the IMAQ AVI Create VI used in conjunction with the IMAQ AVI Get Filter Names VI. Also, what is the RAM available on your computer and what size images are you acquiring and saving to AVI? Thanks!
Kim
Thanks for replying. I'm running labview 2009 on a dual core pentium 2.3 GHz with 4 Gigs of ram. It typically has 2 Gigs free while running the program.
I'm not tryingt write an AVI, I'm trying to read an AVI. The frames are 352 x 240 in size. I've tried several read AVI examples and they all act the same way. They slow down quickly and the hard drive and CPU are really cranking away.

IMAQ AVI read frame error

Hello,
What does the IMAQ AVI read frame error "Trigger Time out" mean ?
Thank you.

Hello Vanessa,
In some applications, when a trigger occurs after several minutes or when integration takes several seconds, the timeout parameter may be too small to wait the amount of time it takes to acquire an image. If the image you request is not ready by the timeout parameter, the acquisition code generates a timeout error.
To prevent this problem, check the acquisition status and request an image only when you know one is ready. By just checking the acquisition status and not requesting an image, you could wait indefinitely for an image without receiving an error.
Sanaa TAZI
Application Engineer
National Instruments

Error -1074395975 occurred at IMAQ AVI Read Frame DirectX has timed out readin

When i run the "Read AVI Example" on every kind of AVI file, I get the error:
Error -1074395975 occurred at IMAQ AVI Read Frame DirectX has timed out reading or writing the AVI file. When closing an AVI file, try adding an additional delay. When reading an AVI file, try reducing CPU and disk load.

The forums search gives two threads talking about this error:
http://forums.ni.com/ni/board/message?board.id=170&message.id=392042&requireLogin=False
http://forums.ni.com/ni/board/message?board.id=170&requireLogin=False&thread.id=195832
Did you allready had a look at them?

Error en IMAQ AVI Read Frame

saludos al foro...
alguien me puede ayudar con el error-1074395975 ocurred at imaq avi read frame.
tengo labview 2011
ni vision 2011
ni vision assistant 2011
directx11
adjunto una imagen del diagrama a bloques y el mensaje de error
gracias
¡Resuelto!
Ir a solución.
Adjuntos:
imagen.png ‏39 KB

vicbit ....tal vez se podría revisar un ejemplo para la versión 2013 que podría servir ...... llamado "Read AVI File.VI" que se encuentra en la ayuda..... como menciona Omar las funciones relacionadas con el manejos de archivos AVI, fueron cambiados en la ultimas versiones asi que saldrá un poco diferente o tal vez el ejemplo no se encuentre . Yo pienso que el truco radica en el uso adecuado de los " Frames per Second" ,"Number de frames" y el "time Delay".
Algo que observe en los códigos que han subido anteriormente es que no es necesario usar dentro del ciclo la funcion "Imaq Create" ya que va a crear un espacio en memoria cada vez que se ejecuta un ciclo (Cada frame) esto no es necesario y podria afectar , además no se estan liberando estos espacios con "Imaq Dispose VI".
A continuacion la imagen del ejemplo que se encuentra en la versión 2013
en la versión 2010 se puede encontrar ejemplos también-->https://decibel.ni.com/content/docs/DOC-14904
Jonathan Cruz
CHALLENGER
K U D O S __ B I E N V E N I D O S

IMAQ AVI Read Frame Trigger Error

I have an application that is creating avi clips of a process. This application is writing frame data which is read later in another application. It is at this point, during the reading of the data that an Error -1074396037 Trigger error is occuring. I am using IMAQ Vision 7.0 and Labview 7.0. Attached is an avi that was created. It consists of a total of 75 frames. Also attached is a simplified version of the frame read part of my application. When reading the frame data I get the error at frames 36 and 51.
I was hoping somebody could have a look and see why I am getting the error.
Terry Sopkow
Sr. Reseach Technologist
Oilphase-DBR
Attachments:
ReadFrame.zip ‏596 KB

Hi Terry,
I ran your program with your video and got error 1074395975 DirectX has timed out reading the avi file. I do not think there is anything wrong with your program because I ran your program with a different avi file and it worked perfectly. I also ran the shipping example Read AVI Example.vi with your video and got the same timeout error.
So there must be something wrong with your avi file. Perhaps frames 36 and 51 are missing or corrupt for some reason. Try creating the avi file again and see if you still have the same problem. If you do, then we'll have to investigate the problem with the creation of the file.
Christopher W.
Application Engineer
National Instruments

IMAQ AVI Read Frame vs. IMAQ AVI2 Read Frame, no data terminal

Hi,
I just noticed when dropping a IMAQ AVI2 Read Frame vi in place of an older IMAQ AVI Read Frame vi, there is no "data out" terminal. I do make use of this feature to add data to the frames of the AVI. Is there supposed to be an alternative way to store this frame data, using the imaq image custom info perhaps?

Hello David,
You are correct in that the data out terminal is no longer available in the AVI2 functions. However you can use the IMAQ Read Custom Data and IMAQ Write Custom Data functions. These allow you to write and read custom data to the IMAQ images using specified keys. In this way you can add miscellaneous data to your images for later use.
Earl C
Applications Engineer
National Instruments

"IMAQ AVI Create" not found under menuitem "AVI" (IMAQ 2.6)

Does anyone know why the Libs. "IMAQ AVI Create ,IMAQ AVI Open ,IMAQ AVI Read Frame ,IMAQ AVI Get Filter Names" are not located in the "AVI" menu ? (IMAQ 2.6)
Thanks Mario

The AVI VIs should be located there, if they are not there was probably a problem with your installation. Launch the installer again by going to Add/Remove Programs and selecting National Instruments Software. From there another menu will open showing most of your NI software. Select on NI-IMAQ 2.6 and select modify. Double check that support for your version of LabVIEW is selected, and proceed with the rest of the install. If you are still having problems, I suggest calling going to www.ni.com/support and getting a hold of NI Tech support.

Imaq avi get info do not retrieve any info

Hi everyone,
I have some trouble with the vision VI IMAQ AVI get info,
everything was working well then I don't know what happened but the VI does not retrieve any information on any files, and I get the following error:
Error -1074395993 occurred at IMAQ AVI Open
Possible reason(s):
IMAQ Vision: File I/O error.
I need the framerate, Width, height and number of frame from this VI or else I cannot develop my application.
it only returns 0 on all values but the number of frames which is not correct 4294967295
I am thinking I might have broken the vision library.
Thanks for your help.

Sorry for the multiple message,
I have found why it did not work it was not the imaq get file info but the IMAQ AVI Open VI that does not like the path string given by the open/Create/Replace File VI.
If you have any idea why it would be appreciated.
Thanks.
Attachments:
Open Avi.vi ‏22 KB

What Web frame work to go with EJB3?

Our coming new project dictates EJB so we plan to use EJB3. But what web frame work is best to go with EJB3? We are currently using Struts1 and EJB2 in our existing project.
We narrowed down to Struts 1, Struts 2, JSF, and Spring MVC. Since EJB 3 is new to us, we don't know which one is best for EJB 3 integration. Anyone can share their experience? Thanks.

I suggest you seam framefork with richfaces components, this framefork integrates JSF + EJB and based on MVC of coarse, so that framework gives you great flexibility to write good application
for jsf UI components you can see this [http://livedemo.exadel.com/richfaces-demo/richfaces/actionparam.jsf|http://livedemo.exadel.com/richfaces-demo/richfaces/actionparam.jsf]
and for seam framework [http://seamframework.org/|http://seamframework.org/]

Where is IMAQ AVI Get Filter Names VI?

I have LabVIEW 6.1 with NI IMAQ 2.6 and NI Vision 6.0.5. I'm trying to create a compressed AVI file from a camera source, and the help file states that there's something called the IMAQ AVI Get Filter Names VI that will return the filters I can use for AVI compression. This VI isn't there in my installation, though.
Am I doing something wrong, or do I need to download something else?

Try looking in the folder C:\Program Files\National Instruments\LabVIEW 6.1\examples\Vision\2. Functions\AVI for the AVI Compressor Comparison.llb example program. This uses the AVI Get Filter Names VI. If this is not available, then you need to upgrade to Vision 7.0 in order to get the functionality to read AVIs into LabVIEW.
Hope this helps-
Julie

.AVI to .avi What is the difference?

Hi-
I am using MPEG Streamclip to trim home movies. When I save my .AVI clip in "Save As" it creates a .avi clip, and when in my MOVIES folder in my Finder, I do not see a thumbnail of the clip anymore, just a clip with the same title, but a lowercase ".avi" not the original ".AVI" uppercase letters.
Eventually I want to take the trimmed clips and put them into iMovie to create a finished product. So, after I trim the movie, does it matter to iMovie if the clip is lowercase .avi or uppercase .AVI? and What happened to the thumbnail image. I just get a stock QT image as the thumbnail. Thanks for any help or ideas. I have the upgrade for iLife08 so I will be working with iMovie 08. Have a nice day, Tim

Lower case or upper case. Doesn't matter. You can answer your question by opening iMovie and trying to import the video. And if the movie doesn't open that another issue.
As for the Quicktime Icon. That's what you get.

I need to move my ITUNES to an external harddrive. I have a few questions based on what I have read.

1. I have the old style organazation, the ITUNES Music. From what I have read I need to go to "Library" and first "consolidate" and then "reorganize". Is that correct and do I need to worry about the order. Or should I just check both boxes at the same time?
2. I understand I can either move the media or move the entire ITUNES file. It seems it is better to move the whole ITUNES file. Is that correct.
3. My understanding that if the external drive is disconnected, the links to the music could be broken. The best thing to do is:
     A. Set all ipods to manual update. This will keep ITUNES from starting every time the IPOD/IPHONE starts up.
     B. Move the entire ITUNES file. This way it will start with a message that the Library cannot be found and one can just cancel the startup.
Correct?
4. One will have to "tell" ITUNES where the new Library resides. To do this in Windows, hold down the "alt key" and start ITUNES. Correct?
5. Before starting make sure ITUNES is updated to the latest version.
Is this pretty much the steps and have I missed anything. I just want to make sure I am doing this correctly so that I don't screw up my links and have problems with ITUNES finding my music.
Thanks for any comments or feedback.
wdpcpa

wdpcpa wrote:
1. I have the old style organazation, the ITUNES Music. From what I have read I need to go to "Library" and first "consolidate" and then "reorganize". Is that correct and do I need to worry about the order. Or should I just check both boxes at the same time?
As far as I know there is no reason not to tick both boxes (if available) then click OK. Once the library has been "Rearranged" that option becomes redundant. Once the process is complete you can close iTunes, rename the folder iTunes Music as iTunes Media and start iTunes again. iTunes should automatically correct the media folder preference to match the new location but double check under Edit > Preferences > Advanced.
2. I understand I can either move the media or move the entire ITUNES file. It seems it is better to move the whole ITUNES file. Is that correct.
Yes.
3. My understanding that if the external drive is disconnected, the links to the music could be broken. The best thing to do is:
     A. Set all ipods to manual update. This will keep ITUNES from starting every time the IPOD/IPHONE starts up.
Not necessary, when your devices are connected you can however untick Open iTunes when this device is connected and under Edit > Preferences > Devices tick Prevent iPods, iPhones, and iPads from syncing automatically.
   B. Move the entire ITUNES file folder. This way it will start with a message that the Library cannot be found and one can just cancel the startup. (Then connect the drive and start as normal)
Correct.
4. One will have to "tell" ITUNES where the new Library resides. To do this in Windows, hold down the "alt key" and start ITUNES.
Press and hold down the SHIFT key as you start iTunes, keep holding until asked to choose or create a library. Click choose and browse to the folder you have moved/copied to your external drive.
5. Before starting make sure ITUNES is updated to the latest version.
No strictly necessary. The steps for moving an iTunes library have remained stable over many builds. Consolidate & rearrange as in step 1, either move or copy the entire iTunes folder to the new location, then connect with the shift-start iTunes method. Copy is slightly safer. Once you are happy it is all working you should ideally backup the new version of the library before deleting the original.
tt2

Have new Airport Extreme via ethernet cable from HughesNet Gen4 modem. Using NetGear WN3500RP extender. NetGear asks for different names for the 2.4 and 5 GHz bands. Most of what I have read indicats extender shoul have same name as main network?

Have new Airport Extreme conneted via ethernet cable from HughesNet Gen4 modem. Using NetGear WN3500RP extender. NetGear asks for different names for the 2.4 and 5 GHz bands. Most of what I have read indicates extender should have same name as main network? How is it best to configure with the Airport Extreme router 802.11ac?

Different names for the 2.4 and 5 GHz networks are optional, but can be convenient for you to distinguish one from another. It's up to you.

What versions of Reader can fill-in forms?

Hi,
I have Adobe Acrobat 9 and I am trying to create a short form. The recipients are not all computer savy and will have various versions of reader so I need this to be super simple.
I have been testing it and Reader 7 doesn't seem to be able to fill-in the form. I have not been able to find any documentation that states what versions of Reader can fillin forms to be returned.
I would also like to have the file emailed back as the filled form, but I understand I do not have to use "distribute forms".
Any help would be appreciated!
Thanks,
C

Actually, the first version of Reader that could take advantage of Reader-enabled documents is Reader 5.1. The problem is backwards compatibility for documents that have been enabled with Acrobat due to various changes since Reader Extensions (usage rights) was first introduced. And for the sake of completeness, versions of Acrobat prior to 8 could apply certain usage rights (e.g., commenting, typewriter), just not those that allow saving a filled-in form.

IMAQ AVI - What is "frame read lookahead"?

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