Flickering color bars in HD render Quicktimes

[Grant Swanson]

Did you apply any sort of color correction in 8 bpc?

Grant Swanson
Visual Effects Supervisor
Video Apex – Minneapolis, MN
videoapex.blogspot.com

[Richard Tsai]

Hi Mark,

I am experiencing the same thing. Were you able to find a fix? The horizontal banding happens only during playback or editing on a Mac. On PCs the files generated play smooth and fine. My only solution right now is to use the QT animation codec.

[Mark Dugas]

Hi Richard,

I found that the issue has to do with a Mac playing back the Avid HD codec QTs, but importing the QTs into Avid is fine. So even though the quicktime movies continue to have color bands when played in Quicktime on the Mac, they look fine when imported into the Avid using Avid DNxHD 220 codec. I have no idea why this happens but at least the final result in Avid looks ok.

[Richard Tsai]

Hi Mark

Thanks for getting back to me. I am using DNxHD 145, 8-bit/59.94i. For me, the problem is present in the QT player but also during playback in Avid. Again, this is on Macs only. I can’t reproduce the problem on PCs and I’ve tested playback on three PCs here. The final delivery will be to a tv station which is pc-based for the online edit but our offline editor is mac-based, and he is experiencing the issue. I am trying to determine whether there is corruption in the movie files themselves or in fact this is purely a codec bug for mac systems. I would appreciate your thoughts. Thanks again.

[Mark Dugas]

Hi Richard,

I am guessing that it is a codec bug for Mac systems. I am importing many of these Quicktimes into a PC Avid system and playback is fine for all of them. If I was you I would send the online facility a few Quicktimes that you know have the issue on a Mac, and make sure they import OK onto their PC Avid timeline.

Mark