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[Solved] Fantastic Codec, a couple questions!

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Bought MagicYUV quite a while ago, and have been using it ever since! Did have a few questions that I wanted to ask, and thought this would be the best place to ask!

So I play/record/edit in 4K, 60FPS, and have been using Dxtory to record all the footage (gaming) as well as Premiere to encode/edit. Haven't had any performance issues whatsoever, codec performs and looks absolutely great.

I wanted to ask what the best settings would be, quality and also performance wise. I tried RGB, and 4:4:4, but ended up just using 4:2:0 as I couldn't notice much of a quality difference, but the files ended up being smaller.

Keep up good work, and thanks for the great product/service!

P.S. I found this post:

"In the general case, recording gameplay is usually sufficient using the YUV 4:2:0 variant of the codec, which gets less than half the bitrate of the RGB variant.

If you really want the highest quality, but still reduce bitrate, YUV 4:4:4 is a very good option, as it retains all the chroma (no subsampling), but still compresses better than direct RGB. So you might want to try that too."

But it doesn't mention RGBA (?), nor 4:2:2. It also doesn't mention which compression method would be best.

Thanks!

 

1 Answer
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Hi!

Thanks, glad it's useful for you!

Well, quality wise you go like RGB > YUV 4:4:4 > YUV 4:2:2 > YUV 4:2:0 in terms of chroma. The reason YUV 4:2:0 is preferred for recording, as it results in drastically smaller recordings (around half compared to RGB) and it usually doesn't matter in the end, as if your final target is Youtube, it'll get converted to YUV 4:2:0 anyway, as h264 uses 4:2:0 on Youtube.

RGBA is not mentioned as it's an alpha format, so it's only needed when you do alpha compositing and need to save video with alpha.

YUV 4:2:2 is largely irrelevant, it's a broadcast format used under special circumstances, mostly interlaced. It's middle ground between RGB/YUV 4:4:4 and YUV 4:2:0. The reason it's not recommended in the general recording case is if you target Youtube, 4:2:0 is good enough, and if you want quality for different reasons (something else than Youtube) then RGB is the way to go, or YUV 4:4:4 in case you want to save space while keeping all the chroma.

I hope it sheds some light to it 🙂

If not, feel free to ask!

EDIT: Regarding compression methods, stick to Median. Dynamic might give a tiny bit more compression, but it's not that much.

EDIT2: And btw, Youtube seems to be accepting MagicYUV videos directly recently, so if you've got the bandwidth, you might try to see if it makes a difference.

FrostFangs Topic starter 24/02/2018 12:56 am

Fantastic answer, thank you so much! Clarified practically everything up for me!

The only other thing I could possibly ask would be the difference between RGB and YUV 4:4:4, if there are no downsides and it saves some space then I may as well use it.

Thank you massively once again, I will continue to recommend your fantastic product to anyone who'll listen  😀 

Balázs Balázs 24/02/2018 1:13 am

Haha, thanks!  I welcome all grassrots/community marketing efforts 😉

 

If you are targeting Youtube, and have no special requirements, then I'd say it's good enough to go with 4:2:0. RGB is pretty much overkill IMO.

 

Regarding YUV 4:4:4, one reason for the space savings there is the fact that YUV by default has the pixel depth reduced a tiny bit. RGB values in 8-bit go between 0-255, while for YUV it goes 16-235 for Y (16 meaning black and 235 meaning white) and 16-240 for U/V by default (called limited range or "studio swing"). This scaling is unnoticable but saves space by making the material compress better. This and the fact that YUV is better decorrelated than RGB and that also results in better compression. The downside is that the RGB-YUV conversion step is not mathematically lossless (though it doesn't matter much).