seamless video loop

dcuke wrote on 7/6/2007, 2:56 PM
I am trying to create a seamless video loop, but once I have finished rendering my loop, I have a small hesitation (1/4 of a second) from the end to the beginning.

I have tried several different ways now to render the file in hopes that this little glitch would cease, but with no luck.

Can anyone help walk me through the process of making a seamless video loop?

Comments

Chienworks wrote on 7/6/2007, 3:29 PM
Where are you seeing the hesitation? In Media Player? Media Player always does that. Try previewing it in Vegas with the loop repeat on. If you've done it right then you won't see any hesitation there.
dcuke wrote on 7/6/2007, 4:02 PM
It is a little difficult to tell using the preview (pre-render) on Vegas as my computer makes the entire preview a little choppy (because of multi-tracks). However, when I take a rendered loop that I have made and preview it on vegas, there seems to be a little hesitation from the end to the beginning again.

I am trying to make video loops for a church software called Mediashout. When I preview my loops on this software it hesitates from the end to the beginning. When I preview professionally made loops on this software, there is absolutely no hesitation.

I think I am doing something wrong on the rendering process. Or mayble a quanitizing problem
fldave wrote on 7/6/2007, 4:31 PM
I've done tons of this. Going from the end of the track back to the beginning makes most computers pause.

Render to new track or an intermediate, then place the resulting clip in a new project. Place 3 or 4 copies of that track on the timeline in a row, no overlap (no transitions) and see if it looks better.

Some of my loops have been as few as 4 frames long, so make sure you have several seconds of the clip on the timeline to see if the loop is really seamless.
Chienworks wrote on 7/6/2007, 6:44 PM
Well, i know Vegas can handle this flawlessly. I've produced hundreds of seamless loops that i've rendered in Vegas.

Place your cursor a few frames before the last frame of the loop on the timeline, step forward a frame at a time with alt-right arrow. You should see a steady progression until you reach the last frame. Then jump back to the beginning of the loop. The progression should continue just as it did when advancing previous frames. If it doesn't look correct doing this then you need to adjust how you're making the loop.

We tried Mediashout for a bit. It was ok, but not terribly impressive. We settled on Songshow Plus from RT Technics. Much more power, more features, lots more real-time editing while the show is running capability. It also seemed a little friendlier towards a broader range of hardware. Tech support is fantastic too. Give it a google and see what you think.
dcuke wrote on 7/6/2007, 10:27 PM
thanks guys for your input. I will try your ideas on when I get back from the weekend.
dcuke wrote on 7/6/2007, 10:31 PM
The songshow plus looks really interesting. I'll download the trial version and play with it for awhile. Do you know if the program is stable or is it apt to crash?

I have been using Sundayplus for a couple of years and have had nothing but trouble with it.
Chienworks wrote on 7/7/2007, 3:38 AM
Sorry, never heard of sundayplus. I'll look it up and see what i find.

The ONLY time we ever had trouble with SongShow Plus was after our church hired an outside IT consultant who installed Norton AntiVirus on all the PCs. After that, not much of anything media related worked at all. Playback rate in SongShow Plus dropped from 29.97fps to about 0.5fps. Changing slides took 5 seconds instead of the 0.3 seconds we had it set for. Even still, the program kept running. *sigh* I purged all things Norton from the PC (a mind-numbingly difficult task) and it works fine again.

We often leave SongShow Plus running on the PC 24/7 for months at a time. In 4 years i can only remember one lock up. RT Technics released a new patch sortly after that and we haven't had any problems since.
dcuke wrote on 7/7/2007, 9:35 PM
Sounds like I should check out SongShow Plus when I get a little more free time to kill.

Anyways, I did try your solutions, but I still get this little hiccup when the loop starts over again. I even tried using vegas on another computer just to make sure that It wasn't my computer, but even then I still get this short hesitation.

I feel like I am missing something when I am making these loops. I have been using Vegas for several years now with great success, but when it comes to these loops, I just can't seem to get it to work seamlessly.

If somebody would'nt mind giving me a "creating loops for dummies on Vegas" crash course, I would be forever grateful.

Perhaps a step by step would show me if I am missing something.

Here is what I am currently doing:

1. take a video put it in a video track
2. split the video in half (A&B)
3. I take the front half (A) of the video & then move it to the tail end of the latter part of the video (B)
4. I overlap B&A approximately 0.25 seconds
5. I highlight the video with the loop region (selecting the new very first frame all the way to the last frame)
6. I choose render and have been saving it as a AVI and/or mpeg1
7. Choose "render loop region only"
8, save project markers in media file
9. save & render

This is how I normally have been trying to do it. I have also tried selecting "quantize to frames", "enable snapping", but I still get the exact same result.

Anyone. HELP!!!
dcuke wrote on 7/7/2007, 9:52 PM
oK! I took another look at fldave's idea. I took my rendered video loop and put it in a new vegas file. I put my new video loop in a track and then stretched it out so that it would play continously a few times on the same track. I used my R-arrow key to cursor through the frames, and once I reached the beginning of my video for a second time, it looks as though 2 or 3 frames at the beginning of my loop are identical (thus causing the appearance of a pause in the loop).

I am not sure what is causing this when I am rendering, but I wll try to put the loop region 2-3 frames from the beginning and try to render again. I'll keep you posted.
dcuke wrote on 7/9/2007, 9:15 AM
Well, that didn't work! I'm starting to think that Vegas has a personal grudge against me.
Chienworks wrote on 7/9/2007, 10:31 AM
What type of source file are you using? Is it MPEG or WMV by any chance? These filetypes use interframe compression, meaning that many of the frames aren't complete, but are built up from previous frames. It could be that Vegas isn't properly handling them at the point where you're cutting. Unless you cut on an I-frame then it could be that Vegas is "punting" and incorrectly building up the frame data around the cut point.

You could try moving the cut point forward or backward a frame at a time and see if there's some point at which the problem disappears. With MPEG the I-frames often occur every 15 frames so it shouldn't take too long to hit one. WMV can often have 60 or 120 frames per I-frame so it could take a lot longer to stumble upon one.

Alternatively, try rendering the original file to a new DV .avi file, then use the new file to split for the loop.
dcuke wrote on 7/9/2007, 1:52 PM
Sounds like something I should try, but what do you mean by "I-frame". My video lingo is not exactly up to par.
dcuke wrote on 7/9/2007, 4:39 PM
Ok! Perhaps ignore what I was saying about the addition of the mysterios extra frame after rendering.

I created a video loop, rendered it, then took the loop in a new vegas file and then stretched the video to create 2 full lengths of the video in the same video track. I pre-rendered it and focused intently on the middle of these two full lenghts. When it played, it was flawless in the middle, which to me means that vegas is proprely creating these loops.

So, I think I have an entirely new/different problem. I am trying to play these loops in different media software applications such as "Mediashout & sundayplus". These programs are designed to take a video loop and properly loop it without any glithces. But, when I play my newly made video loops in these programs, I get this pause (glitch,...whatever) when the loop restarts. However, when I try to use other peoples video loops in the same software, the loops play seamlessly through.

I have been trying different ways to render these loops (usually AVI files). I am wondering if my problem has more to do with codecs/compression.

So! New question! Does anyone have any suggestions as to how I might render an AVI file that is not too large in size, but still looks good?
fldave wrote on 7/9/2007, 4:56 PM
"However, when I try to use other peoples video loops in the same software, the loops play seamlessly through."

Bring several of these into the Vegas media pool or use GSpot to see what format (avi, mpg, wmv) and how much compression is on their loops.