View Full Version : Animation becomes jerky when DVD encoded.

07-16-2004, 03:11 AM
Hi All,
I'm putting a sequence of animations out to a DVD, and I've run into problems.
Although the original sequences run smoothly on the computer, the DVD encoded versions are much more jerky.

I'd better describe my approach in more detail.

I am producing AVI's with minimal compression, (my DVD tools won't work directly from frame sequences, and uncompressed AVI's don't seem to work properly in the authoring packages). These look REALLY good, smooth and detailed on the PC.

I've tried using Nero and Ulead to author the DVD's, but both end up looking twitchy, (as one person said, like bad Harryhausen). I was suspicious of the DVD players I had tried them on, but when I diverted the output to the hard disk it became clear that the jerkiness was introduced at the authoring stage.

I don't know if the subject matter is making this worse - the dominant element is a sequence of planetary flybys. It is very obvious when the viewpoint sweeps past a satellite, it looks almost like whole frames have been ditched (for the satellite component).

I'm trying to think of what else I can do, and I'm running out of ideas.

Can I get Lightwave to produce PAL DVD encoded video directly, to avoid re-encoding?
What settings / codecs etc?

Is there a reasonably priced authoring package that will produce better results?
Maybe one that will work directly from sequences of frames?

All and any clues very gratefully received!


07-16-2004, 03:30 AM
Could you give some insights on your settings you used? Resolution, frame aspect, target frame rate etc...


07-16-2004, 03:43 AM
I'm suspecting your bitrate is too high and out of spec, even though the authoring packages should warn you about that.

A decent deal is TMPGenc with the authoring package ( http://www.pegasys-inc.com/en/index.html ). It compresses from single frame sequences as well.


07-16-2004, 04:06 AM
Thanks for the suggestions - I'm not at home at the moment, so can't check everything but...

For the LW Camera setting, I just picked PAL DVD from the camera options, and let that take care of the size and aspect.

The authoring packages are transcoding the video clips, so I don't see how they could create an unacceptable data rate. (Also, when playing back the transcoded stream on the PC, its much lower data rate thn the source that plays smoothly).

TMPGenc looks like its worth a shot, I noticed from the web pages there's a trial version available.

I'm beginning to wonder, (since writing the first message) if the packages are changing the frame rate - from memory I was working to 30 FPS in LW. Dropping frames to change the frame rate would certainly look like what I am seeing...

Or could it be an interlace thing?

Thanks again guys,

07-16-2004, 04:24 AM
Are you creating an NTSC animation?

PAL is 25fps, so if your source movie is 30fps, and you're going out to a PAL DVD, you certainly have a problem there...

In that case I'd even suggest a re-render in 25fps...


07-16-2004, 04:27 AM
That certainly sounds like the answer.

Brilliant, thanks guys!!!

:D :D :D

Does anyone know of a way of changing the header in the AVI, and telling it to play back at a different rate without rerendering?

With the scenes I have, the slightly slower speed would not cause any problems. (In fact 20% more footage would be a bonus!)


07-16-2004, 04:46 AM
I just hope you didn't render out to the AVI, but to single frames...

If you still have the frames, load them in LW as a backdrop image in a 25fps scene, and render them out to an AVI.

You could also have a look at www.virtualdub.org ,it might allow you to change the header (AVI swiss pocket knife :) ).


07-16-2004, 06:20 AM
Thanks again guys - I found a couple of promising looking frame rate tweakers on the web, I'll get cracking this evening.


For my recent stuff I have the individual frames, but this looks easier. And even with 400 Gb of hard disk, it sure gets used up quickly!!!