very strange artefact with XAVC-I

Mindmatter wrote on 2/19/2019, 4:01 PM

Hi all,

here's one I haven't seen since the days low rez jpegs...sawtooth lines. ( the legs )

It's from a Sony FS7, rec 709, 4:2.2 10 bit...just the weirdest thing. There's another shot where it's simply OK, but I wonder what's wrong with this one? I sometimes also get those lines with certain FX like the luma key. Snapshot taken at best/full. Any ideas?

Thanks!

Comments

Mindmatter wrote on 2/22/2019, 10:37 AM

anyone...? This is really weird.

Marco. wrote on 2/22/2019, 10:53 AM

Is this the Sony FS7 source file? Not yet transcoded?

Mindmatter wrote on 2/22/2019, 10:53 AM

yes Marco. It's on the leggings of a person in another clip too, but most seem normal.

Marco. wrote on 2/22/2019, 11:08 AM

And you mean these kind of jags:

This looks similar like not being 4:2:2 but 4:2:0. Did you analyze these particular shots (via MediaInfo or something else) if they are really 4:2:2?

Mindmatter wrote on 2/22/2019, 12:53 PM

Marco, yes exactly those jags. Looks just awful.

Yes they are 4:2:2. 10 bit, 124mB/s, just checked.

Marco. wrote on 2/22/2019, 1:13 PM

If you have a very similar shot available which looks fine I would try transcoding this one into a 4:2:0 type. If this then looks jaggy like the one above I'd guess there's a camera encoding issue.

Mindmatter wrote on 2/24/2019, 5:48 AM

Thanks Marco, I'll do some testing tomorrow. Meanwhile, someone in an FS7 group on FB had the same issue and said it got resolved with a factory reset, which I just did just in case. I'll keep you posted.

Thanks!