[FFmpeg-devel] [PATCH] avcodec/nvenc: High bit depth encoding for HEVC

[Roman Arzumanyan]

Thanks for the explanation, Timo!

I was hoping that 8>10 bit up-conversion which happens in the driver may
bring some goodness like SDR > HDR conversion, recently presented by NV. Or
some other algo which is easier to keep proprietary.
Otherwise, although it is convenient in some use cases, it doesn't look
more tempting than, say, a similar 8>10 bit NPP up-conversion which shall
yield the same (presumably SoL) performance.

чт, 18 апр. 2024 г. в 16:32, Timo Rothenpieler <timo at rothenpieler.org>:

> On 18/04/2024 14:29, Roman Arzumanyan wrote:
> > Hi Diego,
> > Asking for my own education.
> >
> > As far as you've explained, the 8 > 10 bit conversion happens within the
> > driver, that's understandable.
> > But how does it influence the output? Does it perform some sort of
> > proprietary SDR > HDR conversion under the hood that maps the ranges?
> > What's gonna be the user observable difference between these 2 scenarios?
> > 1) 8 bit input > HEVC 8 bit profile > 8 bit HEVC output
> > 2) 8 bit input > 10 bit up conversion > HEVC 10 bit profile > 10 bit
> > HEVC output
> >
> > Better visual quality? Smaller compressed file size?
> > In other words, what's the purpose of this feature except enabling new
> > Video Codec SDK capability?
>
> Video Codecs tend to be more efficient with 10 bit, even if it's just 8
> bit content that's been up-converted to 10 bit.
> I.e. yes, it'll (Or can, at least. Not sure if it's a given.) produce
> smaller/higher quality content for the same input.
>
> As for the exact reason, I can't explain, but it's a well known concept.
>