Converting 8 bit 4k 4-2-0 to 10 bit 1080p 4-4-4 ProRes

I just read this article about the new GH4 and it's pretty interesting and another great selling point of the already awesome sounding camera.

The main thing I don't understand is how to convert the footage. Is it as simple as just creating a 10bit 4-4-4 1080p ProRes setting in compressor and just batch converting all the files? Or is there more to it than that? Can I just edit in a 4K timeline in FCPX and just export the project as a 1080p 4-4-4 ProRes master file? It's seems like I would need to have the clips already converted if I wanted to use the 10 bit 4-4-4 color profile to work with, so maybe convert to 2K in compressor so I can have room to crop and reframe the 10 bit 4-4-4 files and then export to 1080p from there.

I saw an article kind of like that too.

I am guessing maybe using After Effects? There's an option to adjust clips in AE from 8-bit to 10- and 12-bits

Found the link I was talking about

www.eoshd.com/content/12140/discovery-4k...erts-1080p-10bit-444

There is a lot of misunderstanding about upsampling video.

As Pollux pointed out: when you record in 4K 8-bit 4:2:0 (not only with the GH4) and you upsample the video to 10-bit 1080p you will get better upsampling results because the converter has more color information to create subsamples for the missing color information.

Will the resulting video look as good as when you had shot it in 10-bit 4:2:2 or 4:4:4 from the start? No, absolutely not. When you lose color information while shooting (due to the heavy compression from the recording codec) this information is lost and you never can get it back.

But it is a good workaround for restoring lost color information when you shoot 4K and you edit in 1080p.

Now should you do this before importing? Absolutely not. If your system allows you to work with native 4K AVCHD in realtime, converting all your footage prior to importing would be a tremendous waste of time and drive space. Remember: FCP X internally works in 32-bit float, not in 8- or 10-bit. So your video gets decompressed once it's on the timeline, and it gets recompressed when you export. If you work with native 4K 8-bit 4:2:0 in a 1080p timeline and you export as ProRes 4:4:4:4 this is exactly the same as if you would convert the 8-bit 4K files to 10-bit 1080p before importing. Only here you only convert the shots you have used, and not all the footage you have shot

Of course if your system is not fast enough to handle 4K AVCHD natively it would be better to do the upsampling prior to editing, or to work with Proxy files for editing.

Just remember: this only works when you upsample to 10-bit and you downconvert to 1080p at the same time. You will lose any ability to reframe 4K in post without losing quality.

If you really want to work with 10-bit quality 4K while shooting with the GH4: use the HDMI output and an external 4K recorder. This will save you a lot of time and headaches. I think we will hear more about this in the next few days.

-Ronny

Atmos just announced an external 4K recorder. That's the one to watch

Yep, that's it

You will need the little SDI box on the GH4 for that.


-Ronny

ronny courtens wrote: ...when you record in 4K 8-bit 4:2:0 (not only with the GH4) and you upsample the video to 10-bit 1080p you will get better upsampling results because the converter has more color information to create subsamples for the missing color information...Will the resulting video look as good as when you had shot it in 10-bit 4:2:2 or 4:4:4 from the start? No, absolutely not. When you lose color information while shooting (due to the heavy compression from the recording codec) this information is lost and you never can get it back...But it is a good workaround for restoring lost color information when you shoot 4K and you edit in 1080p.

If the final goal is 10-bit 1080p 4:2:2, I think the GH4 can do that without the DMW-YAGH interface unit by using existing HDMI recorders like the Atmos Ninja. That seems relatively inexpensive for that capability.

There are no compatible 4K HDMI recorders yet, but (as you said) the GH4 can output 4k 4:2:2 via HDMI:

nofilmschool.com/2014/03/panasonic-gh4-1...wt_m=3dBDmahM1.BjwS7

Absolutely. But that, of course, takes away the capability of using 4K in a 1080 timeline for reframing purposes as the OP said.

-Ronny

The Atomos one just announced that I was talking about can take 4K via HDMI and it's called Shogun

nofilmschool.com/2014/04/camera-mounted-...ket-size-ninja-star/

VERY interesting stuff

Yes, the Shogun is really cool. Had a chance to check it out and see it today. On top of being able to take HDMI AND HD-SDI (and do pass through and conversion between the two) it also is a really beautiful kick ass color accurate monitor. Atomos is delivering some pretty amazing stuff.

So any word about the price?

Confirmed under $2k, but specifics not figured out yet.

That's not bad.

So a GH4 w/Speedbooster and that new Atomos recorder will make a pretty nice 4K package