up convert to 10-bit low BR from 8-bit high BR

[Trebuin]

I'm relatively newer to the 8/10 bit color scheme but wanted to double check this. I have a very high bitrate source video in 8-bit colors. I'm assuming I won't see any benefit trying to reduce the bitrate down to 1/4 the original size, but up-converting the colors to 10-bit because the colors are already defined, correct?

 

[Ritsuka]

10bit might help to remove some banding artefacts in gradients and dark area. But it won't reduce bitrate by much, and 10bit H.264 is not well supported by hardware decoders.

 

[Trebuin]

10bit might help to remove some banding artefacts in gradients and dark area. But it won't reduce bitrate by much, and 10bit H.264 is not well supported by hardware decoders.

Actually, I've been moving my material to x265 10-bit. The problem is some of my older stuff is already 8-bit but at a higher bitrate. The only real benefit from 10-bit I'm looking at reducing the banding. What I think will happen, though, is that since the materials are already limited by the 8-bit color pallet, any banding will already be there & there's now no gain from upgrading to 10-bit. Just because the material has a higher bitrate doesn't mean that the colors have any extra that could benefit from 10-bit. That's my theory anyways.

 

[joema2]

...The only real benefit from 10-bit I'm looking at reducing the banding. What I think will happen, though, is that since the materials are already limited by the 8-bit color pallet, any banding will already be there & there's now no gain from upgrading to 10-bit...

I think that might be right if you are talking about fixed resolution, IOW from 1080p 8-bit at a high bit rate to 1080p 10-bit.

However you *can* supposedly trade resolution for improved color space and bit depth. 4k 8-bit 4:2:0 can be transcoded to 1080p 10-bit 4:4:4, provided it's not scaled. This has been debated but the people saying it's possible are highly credible industry figures: https://www.provideocoalition.com/can-4k-4-2-0-8-bit-become-1080p-4-4-4-10-bit-does-it-matter/

 

[Ritsuka]

If you are encoding to HEVC, you can use 10bit safely.

 

[Trebuin]

If you are encoding to HEVC, you can use 10bit safely.

But what I've been trying to confirm is that using 10bit on an 8bit source will be a waist of space as there will be no elimination since it will likely be created in the source material due to the original 8bit encoding.

 

[Ritsuka]

You won't waste space if you encode to 10bit. But I wouldn't encode an already compressed h.264 video to hevc.

 

[Trebuin]

You won't waste space if you encode to 10bit. But I wouldn't encode an already compressed h.264 video to hevc.

I've recoded plenty of 264 to hevc & managed to pull off about 30-50% space savings for the exact same quality. If I transcode a 1080p video 2hrs to 8bit hevc, my standards have it sized about 2GB. 10bit hevc at the same quality is around 2.3GB to 2.5GB so it does in fact add up.