DVD Architect 5.2 Question

[Dave Haynie]

Sounds like you’re doing the right thing, pretty much.

For the “jumpy” pans, check that’s not the original video itself. At 24p, a fast pan can simply be jumpy. One thing you can do to minimize this is follow the typical cinematographer rules for shooting, such as using the right shutter speed. A typical film is shot with a 180 degree shutter, which would be 1/48th second for 24p. If you shoot with a much faster shutter speed, you’ll eliminate the natural motion blur of a pan. So you’ll have nice, static frames (in theory… read below), which “jump” one to the next.

That might not happen, but not for a good reason, but due to the AVC compression on the 60D. Interframe compression CODECs like AVC and MPEG don’t deal well with any situation that has too much information changing frame to frame too quickly. That’s precisely what a pan does, and the faster the pan, the worse it’s going to look. If you need a fast pan, the best you can do it shoot it at a faster rate, 60p maybe, then add some motion blur when you downconvert to 24p. You might try applying

Having studied a little of how professional mastering is done on DVDs, I recommend looking at any similar section of a DVD or BD, frame by frame. A mastering engineer can tweak individual GOPs when creating a DVD, changing frame rate and tweaking the video on the fly. What they typically do for a high motion scene, to avoid macrocell blocking, is to bump up the encoding rate, but also add a low-pass filter (eg, a blur) to minimize the high frequency information in the whole picture, thus lowering the macrocell to macrocell changes even before the MPEG encoding is done. You can do a little of this in Vegas by pre-blurring segments with high motion in them, but that’s not going to help if you’re already.

You can try a motion blur envelope on the jumpy pan, see if that helps. I use Boris Continuum Complete, which has a number of additional motion blurs, but the built-in is enough to make some progress. If that’s not enough, try a tiny bit of panning. Basically, use pan/zoom to zoom in just a bit on your “jumpy” pan. Set the start and end keyframes of your pan to have the pan move in the direction of the original motion. Adding a supersampling envelope may make this look better… you can mess around with this stuff, see what works in your particular case.

-Dave

[Mark Grady]

Thank you, Dave. I greatly appreciate the detailed feedback.

The originating footage looks fine. The “jumpy” pans only occur on the DVD. I’ll explore your other recommendations.

Again, thank you very much for going to the trouble of such a detailed response.

Best to you.

[Dave Haynie]

The other really sort of jumpy pan you can run into, which I didn’t mention, is due to an interlacing inversion. You’ve shot and rendered progressive, so this shouldn’t be an issue.

But basically, what happens in interlaced video is of course that one field is temporally ahead of the other. If this gets inverted, what you see is video with unwatchably horrible judder in any motion, as you’re jumping backwards and forwards in time constantly.

Should be impossible rendering from 24p, regardless of the target format, but I just figured I’d mention it.

-Dave