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mjgraves  
#1 Posted : Wednesday, July 27, 2016 6:11:00 PM(UTC)
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Does the combination of vMix and NDI have any ability to cope with a 4:4:4 stream? More specifically, could the vMix Chroma keyer handle it?

I can envision a camera like the forthcoming sub2r device delivering 4:4:4, which would allow for superior quality green screen compositing.

Michael
admin  
#2 Posted : Wednesday, July 27, 2016 10:26:56 PM(UTC)
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The specs of the sub2r say 10-bit raw RGB. As this is probably a bayer pattern, this would mean two green pixels for every
red and green pixel, which when debayered ends up being close to 4:2:2 anyway.

4:2:2 is used at the highest broadcast levels for chroma key and is also what NDI uses, so I don't think there is need for 4:4:4 at this time.
mjgraves  
#3 Posted : Thursday, July 28, 2016 10:29:51 AM(UTC)
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admin wrote:
4:2:2 is used at the highest broadcast levels for chroma key and is also what NDI uses, so I don't think there is need for 4:4:4 at this time.


Coming from the broadcast and post-production space, I've worked in 4:4:4, and even 8:8:8 in the past. As you say, it's not used in broadcast, but it is used in post. I accept that it's likely out of scope for vMix.

I've seen a few people who were seeking USB 3 attached 4K cameras so that they could derive 1080p @ 4:4:4. In both cases the people asking me about this were taking the result to XSplit.
jhebbel  
#4 Posted : Thursday, July 28, 2016 10:36:40 AM(UTC)
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mjgraves wrote:
admin wrote:
4:2:2 is used at the highest broadcast levels for chroma key and is also what NDI uses, so I don't think there is need for 4:4:4 at this time.


Coming from the broadcast and post-production space, I've worked in 4:4:4, and even 8:8:8 in the past. As you say, it's not used in broadcast, but it is used in post. I accept that it's likely out of scope for vMix.

I've seen a few people who were seeking USB 3 attached 4K cameras so that they could derive 1080p @ 4:4:4. In both cases the people asking me about this were taking the result to XSplit.


4:4:4 is used in post alot as raw video archive, but at that point if its in post, NDI isn't really much of a concern anymore. If you want to archive in 4:4:4, I would suggest archiving directly at the camera (if possible).
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