x265 HEVC Encoder

[quietvoid]

Originally Posted by Boulder

Does the feature work with decoders out of the box, or is it some extension that is not mandatory for compliance?

It's not mandatory as it's SEI.
I don't know of hardware that supports it.

FFmpeg does support it in software, and libplacebo in shaders.

[vadlerg]

Originally Posted by jpsdr

Made a build of new version of my custom mod. Also add an AVX LLVM version, don't remember who asked for it...

Thanks !

[benwaggoner]

Originally Posted by quietvoid

No it's not. It's for the H.265 Film grain characteristics SEI message. Or now it's better to reference it as H.274 FGS.
It can be used to generate the expected binary file.

Oh, I haven't heard much about that yet. What's the intended use case?

[quietvoid]

Originally Posted by benwaggoner

Oh, I haven't heard much about that yet. What's the intended use case?

Film grain synthesis in MPEG codecs. It's been specified for decades and is still barely seeing any use.

[benwaggoner]

Originally Posted by quietvoid

Film grain synthesis in MPEG codecs. It's been specified for decades and is still barely seeing any use.

Oh, the old optional one from HD-DVD? I haven't looked at it in AGES, but I remember it not being very capable.

AVFG1 is a much better FGS implementation.

[LigH]

Sounds like the next more complex model beyond "noise reduction" (--nr-[inter|intra]) in x265, which was more a modelling than a simple reduction too.

[FranceBB]

Hey guys, I know most of you saw the screenshots of the 56c/112th and other Intel Xeon monsters CPU I use at work, but you should know that at home I'm still using an old i7 5930K CPU 6c/12th at 3.50GHz which can go up to 4.00GHz.
It served me fairly well over the years, but it's getting older and older and I was thinking about buying a new one.
Unfortunately, nowadays Intel seems to be focused on releasing CPUs with mixed cores only for consumers so much so only Intel Xeons have the good old normal cores, but I'm too broke to afford one.
This means that I'll probably end up buying another consumer CPU (like the Core Ultra or whatever they named them now that they killed the i7-i9 nomenclature) which has Efficiency cores and Performance cores.
I know that the efficiency ones are low powered, low clock and also miss some instruction set support like they don't have full AVX512 support etc while the Performance cores have a higher clock and full instruction set support (SSE, SSE2, SSSE3, SSE4.1, SSE4.2, AVX, AVX2, AVX512). The idea being that the Efficiency cores are supposed to be used for low intensity background activities like checking your email while the Performance cores are supposed to be used for high intensity activities like... encoding I guess.

So, the question is:

assuming I'm on Windows 11 on a new PC and I fire up my good old x265 BAT to encode from an AVS Script.avs as I've always done, what's gonna happen?
Is it only gonna use the Performance cores?
Is it gonna use both the performance and the efficiency cores in a very bad way so that once a frame is split in the various threads I'll end up with the performance cores waiting for the efficiency cores to finish their piece (i.e threads synchronization) and thus they'll impact performances negatively?
Is everything gonna work smartly automagically as it's handled by the OS (Win11) and I don't have to care about it?


Sorry for the various questions, but this is almost definitely gonna impact my choice of what to buy 'cause depending on the answer and given the prices of the Xeon nowadays, I'm flirting with the idea of moving to AMD.

[TDS]

Originally Posted by FranceBB

I'm flirting with the idea of moving to AMD.

I have been using AMD's for a lot of years, I still have a 3950X, 5900X, 5950X, and when the 7950X were released I knew I had to get one.

I exclusively use RipBot264, and the 7950X is an encoding beast, BUT, 16C CPU's do have issues with x265 encoding, but due to the "behind the scenes settings" in RipBot, this can be easily overcome.

But then the 13th Gen Intel's came out, so took a big chance and got a 13900KF, I wasn't sure how the different architecture would work, but after some time fiddling around, I'm more than happy with it.

In a head to head encode, the 7950X is just slightly faster...I would think that the 14th Gen Intel's maybe a little faster.

And to just sum up, you could build an Intel system quite a bit cheaper that an AMD, DDR4 vs DDR5, but one thing that IS very important, you WILL need a really good cooling system, as both run really hot, but they are stable as.

PS:- No AVX512 support on the Intel's Hadn't heard of the Core Ultra 'til your post.

https://www.intel.com/content/www/us...-vs-ultra.html

[benwaggoner]

Originally Posted by LigH

Sounds like the next more complex model beyond "noise reduction" (--nr-[inter|intra]) in x265, which was more a modelling than a simple reduction too.

it's about grain reconstruction based on metadata, ala AV1's Film Grain Synthesis. But a very old basic version originally designed for H.264. The only platform that supported it IIRC was HD-DVD, but AFAIK it wasn't ever used on actual discs. People thought it was limited at best back then.

Perhaps coupled with modern de-grain and parameterization technology, maybe?

I think AVFG1 is more likely to be important.

[benwaggoner]

Originally Posted by TDS

PS:- No AVX512 support on the Intel's Hadn't heard of the Core Ultra 'til your post.

https://www.intel.com/content/www/us...-vs-ultra.html

AVX512 hasn't been all that helpful for x265 outside of 4K resolutions at slower presets. It's probably not a big loss.

[qyot27]

Originally Posted by FranceBB

assuming I'm on Windows 11 on a new PC and I fire up my good old x265 BAT to encode from an AVS Script.avs as I've always done, what's gonna happen?
Is it only gonna use the Performance cores?
Is it gonna use both the performance and the efficiency cores in a very bad way so that once a frame is split in the various threads I'll end up with the performance cores waiting for the efficiency cores to finish their piece (i.e threads synchronization) and thus they'll impact performances negatively?
Is everything gonna work smartly automagically as it's handled by the OS (Win11) and I don't have to care about it?

If it's anything like macOS, the efficiency cores are executed second.

Not using x265, but an example of the core topology is included in this post from 2022. Short answer: if Intel's heterogenous architectured CPUs act the same way in conjunction with the thread scheduler in Linux and/or Windows, just use Prefetch() to target the Performance cores if you don't want them mixing.

[excellentswordfight]

Originally Posted by FranceBB

assuming I'm on Windows 11 on a new PC and I fire up my good old x265 BAT to encode from an AVS Script.avs as I've always done, what's gonna happen?
Is it only gonna use the Performance cores?
Is it gonna use both the performance and the efficiency cores in a very bad way so that once a frame is split in the various threads I'll end up with the performance cores waiting for the efficiency cores to finish their piece (i.e threads synchronization) and thus they'll impact performances negatively?
Is everything gonna work smartly automagically as it's handled by the OS (Win11) and I don't have to care about it?

I've been encoding on Intels CPUs pretty since they introduced the hyrid architecture. And yes, that pretty much the case. From a performance perspective everything is pretty much just working, I have played with turning of e-cores etc, but I gain nothing from it, there is a net profit in using the e-cores. And as the e-cores have better performance per watt, in cases were you are power restricted (which is always now days) and can saturate the extra threads you will get more performance of having say 4 e-cores, compared to having 1-2 extra p-cores, or giving existing p-cores more of the power-budget.

With that said, its not all smooth sailing, windows does weird shit with its scheduler. For example, if you minimize the application you are encoding with (this is at least the case when running applications through CMD) that application will no longer use p-cores AT ALL, as windows now treats it has a "background application". This can be enjoying, and even a dealbreaker as it can also be triggered just by running something in fullscreen infront of it. But I actually use it as a feature, cause if I wanna game while encoding i just minize it will free up the p-cores completely.

With that said, for just a straight up encoding machine, if we are talking about consumer CPUs I would just get a 7000-series Ryzen instead given the huge performance/w advantage in this performance class (Intel is actually not that bad in this regards if you limit your CPU at say 125W and below) and there you really dont have to care about any hybrid core stuff. Ignoring downclocking and powerlimits etc, out of the box, 7950X gets 90% of 14900k encoding performance at 1/2 of the power concumption.