Help! Red pixelation/banding/fringing?

C

catalyst

Member
Hello,

I've taped an on-stage production for a local association. Looked great when I taped it, and looks pretty good watching directly from my DVX100B on an LCD TV via composite.

When I import the video into my PowerMac (Dual G5 1.8, FCP 5.1.4), I start seeing noticeable pixelation/banding/fringing, especially in reds, and especially (but not only) against dark backgrounds. This seems to get worse when I export to Compressor (even looking at the source side), and export using a 2.9 mpbs average rate (trying to get 136 minutes onto a DVD-5) seems to make it even worse; setting higher average rates doesn't improve things, at least in preview.

Now, I might be imagining that it was all that great to start with. And, turning down the saturation and applying some blur (red) seems to help. But I was hoping someone here might recognize this problem and have a suggestion on how to improve the situation.

You can see a sample frame at the URL below, with saturation turned down a bit (73) but the blur not applied.

http://www.catalystdigitalstudios.com/DanceRedPixelation1.jpg

Thanks for any help!

Catalyst
 
Thank you for posting a still- I wish more folks would do this as it's a huge help in getting to the root of the trouble fast. :)

"This" is interlacing- that is from 24p footage with its pulldown intact. Color fringing looks about normal for DV played in the desktop proxy on a computer monitor within FCP. What you see within the Canvas in FCP is an RGB generated preview of your footage. To see the actual look, you need to play out to Firewire and to a decent broadcast monitor or TV. But realistically speaking bright red details on a sharp edge over black in DV's limited color space is likely to lead to chroma sampling errors. They will be a lot less pronounced on TV but they'll still be there.

Noah
 
Last edited:
Hello Noah,

Thanks for this info. Does your assessment apply to 60i footage? This was captured using the DVX #1 preset.

Thanks!

Catalyst

NoahK said:
Thank you for posting a still- I wish more folks would do this as it's a huge help in getting to the root of the trouble fast. :)

"This" is interlacing- that is from 24p footage with its pulldown intact. Color fringing looks about normal for DV played in the desktop proxy on a computer monitor within FCP. What you see within the Canvas in FCP is an RGB generated preview of your footage. To see the actual look, you need to play out to Firewire and to a decent broadcast monitor or TV. But realistically speaking bright red details on a sharp edge over black in DV's limited color space is likely to lead to chroma sampling errors. They will be a lot less pronounced on TV but they'll still be there.

Noah
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