video scrub bar

[Grasshoper]

Has anyone ever successfully made a video scrubb bar? I have the full NI Vision Development module. Working with avi files. Trying to wrap my brain around this and it's just not coming together. Any advice is greatly appreciated.

[Hatef.fouladi]

what is your means about  scrubb bar ?! could you explain more about it ?

[Bob_Schor]

Yes, we have (or rather, my student, just getting started with Image Processing in LabVIEW, did this as one of her first IMAQdx routines).

Bob Schor

P.S. -- if you really want to show how cool you are using (misspelled) jargon such as "Scrub bar", you'll have better luck posting in the Video forum.  I also didn't know the term, and when I searched it with your spelling, got no hits.  But I persisted ...

[Grasshoper]

So what I've gathered from your response is that I'm not refering to this with the correct terminology. Fine. What do I need to call it in order to return search results? And for the record, I spent a good few minutes trying to figure out how to post this to a more specific forum. If you notice under my user name, this is the first post I've ever made. Cut me some slack.

[RavensFan]

We don't know what the correct terminology would be because we don't know what you are asking for.

Try attaching a picture that shows what you are talking about.

[NIquist]

It's actually a pretty common term dating back the reel-to-reel recorder days of analog audio.  Also called a jog/shuttle control it's used to interactively fast forward and reverse an audio or video recorder to allow for efficient editing.  Many high-end VHS recorders had them before tape went obsolete.  

https://en.wikipedia.org/wiki/Jog_dial

I don't do much video with LabVIEW but if I can find any relevant info I'll post back...

[Grasshoper]

I finally found something that does basically what I need it to here http://forums.ni.com/t5/LabVIEW/Slider-for-Display-and-Control-Time-of-Video/m-p/2927406/highlight/t... In that Read AVI File2.Zip. The only problem it has is if I drag what they have labeled the "progress bar" back to a location prior to it's current location in the video, then allow it to continue playing, it won't play through the rest of the video frames. It simply plays the rest of the frames it thought it had remaining given the number available at the start and then stops the VI. Somehow, I need the VI to update the number of frames remaining in the video based on the progress bar location.

[James.M · Accepted solution]

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@Grasshoper wrote:

I finally found something that does basically what I need it to here http://forums.ni.com/t5/LabVIEW/Slider-for-Display-and-Control-Time-of-Video/m-p/2927406/highlight/t... In that Read AVI File2.Zip. The only problem it has is if I drag what they have labeled the "progress bar" back to a location prior to it's current location in the video, then allow it to continue playing, it won't play through the rest of the video frames. It simply plays the rest of the frames it thought it had remaining given the number available at the start and then stops the VI. Somehow, I need the VI to update the number of frames remaining in the video based on the progress bar location.

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That's because they used a For loop, which I find strange. Kinda defeats the purpose of the Progress Bar being a control. Change it to a While loop and add a Stop condition for when the video ends.

I don't have the vision module, but this is what I would do:

[Gregory]

Right click on the For Loop and click "Replace with While Loop". Now it will run indefinitely until an error occurs (which happens when it exceeds the number of frames) or you press the stop button on the front panel. You can make it stop without error if you wire the "Progress Bar" control terminal to "Greater or Equal?" than the "Number of Frames" wire to the stop condition of the while loop.

[Grasshoper]

Works like a charm 🙂 The only other thing I'm interested in is adding a play/pause button.