How can I get rid of this aliasing?

DVD Authoring

How can I get rid of this aliasing?

Posted by Phil Bates on June 30, 2011 at 3:46 pm

I am working on a guitar player’s DVD and the resulting transcoded video looks like it’s doing some line-skipping, or some other resolution compromise. If you look at the guitar strings on the attached image and compare the Quicktime on the left and the DVD image on the right you can see the aliasing. They flash terribly when playing in real time. The QT source movie is Progressive, NOT interlaced. I used the auto transcode feature of Encore.

I was wondering if Bitvice transcoding could do better. So I tried a sample M2V and imported it into Encore. Unfortunately, Encore will not build a DVD with the Bitvice M2V so I am stuck.

Can anyone help?

Thanks,
P

Jon Geddes replied 14 years, 10 months ago 4 Members · 5 Replies
5 Replies

Andreas Gumm
June 30, 2011 at 4:56 pm

Do you use the actual BitVize version 2.98?
Which progressive frame rate do you use, 23.98 fps or 29.97 fps?

Andreas Gumm
selfemployed media author
Phil Bates
June 30, 2011 at 6:53 pm

Yes, Bitvice 2.9.8 and progressive 29.97fps

Thanks,
Phil

Phil Bates
http://www.artbeats.com
Rob Neidig
June 30, 2011 at 6:55 pm

Phil,

If you are starting from HD footage, we have found we get better results going to DVD by transcoding to a standard definition Quicktime first, then transcoding that Quicktime to MPEG-2 for the DVD. The aliasing you are seeing could very well be caused by the downconversion from High-Def to Standard-Def/letterboxed. We use Final Cut Pro and output an original Quicktime in the Apple ProRes codec (which is what we use on the timeline). We then run that ProRes QT file through MPEG Streamclip to downconvert it to standard def. Then we take that QT and use Compressor (with a Cinemacraft encoder plug-in) to convert to MPEG-2. Note that MPEG Streamclip will crop the video slightly on the sides, but overall the better look is worth losing a few pixels.

Have fun and say “Hi” to Brooks for me. I did a DVD with him and Buster B. (in Standard Def), as well as duplicated a bunch of his CDs before he moved to PDX. He’s very talented and a good guy.

Rob

Rob Neidig
Eugene

Rob Neidig
R&R Media Productions
Eugene, Oregon
Phil Bates
June 30, 2011 at 9:10 pm

Rob,

Thanks for the post. We are pretty much doing the same thing as you, only we are using After Effects for the down conversion to 720 x 480 widescreen format, 29.97 progressive. Then we import those QT movies into Encore. The down-converted QuickTimes are pristine so the problem is being introduced by Encore in some way. Before I try another external encoder (like Cinemacraft) I would like to see if we can just make some kind of adjustment in Encore that I don’t know about.

[I’ll tell Brooks you said hi.]

Thanks again but we still need to figure this out…

Phil

Phil Bates
http://www.artbeats.com
Jon Geddes
July 15, 2011 at 9:52 pm

No adjustment in Encore will solve the problem unless you have frame blending enabled (by default, it should be turned off). You may just need to use a better quality encoder. If you’d like, I can encode a short 5 second clip for you to see the difference using a studio quality encoder. If you are interested, please send me an email: jon (at) precomposed.com

Jon Geddes
http://www.precomposed.com

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