x265 HEVC Encoder

[benwaggoner]

Originally Posted by Greenhorn

Oddly, enabling ssim-rd by itself will disable psy-rd, but if you manually specify both they'll both be used.

Have you confirmed they are both operating, or is it possible one overrides the other?

If psy-rd + ssim-rd looks different than just psy-rd OR ssim-rd, than they are doing something together. But it wouldn't be surprising if different rd modes can't operate simultaneously. Although, algorithmically, I could see these being able to function simultaneously.

[Greenhorn]

Originally Posted by benwaggoner

Have you confirmed they are both operating, or is it possible one overrides the other?

If psy-rd + ssim-rd looks different than just psy-rd OR ssim-rd, than they are doing something together. But it wouldn't be surprising if different rd modes can't operate simultaneously. Although, algorithmically, I could see these being able to function simultaneously.

That was an embarrasing mistake on my part. While the x265 CLI output will imply that both psy-rd and ssim-rd are enabled if you specify psy-rd after ssim-rd, it produces bit-identical output to not having ssim-rd enabled.

Similarly, enabling ssim-rd without doing anything to psy-rd is identical to manually disabling psy-rd. The encoder is clear about this, though, so hopefully I didn't manage to confuse anyone reading about that.

[jlpsvk]

what's better? ssim-rd or psy-rd?

[microchip8]

Originally Posted by jlpsvk

what's better? ssim-rd or psy-rd?

psy-rd... again, from my own testing ssim-rd produces visual distortions in some samples I tested long ago. ssim-rd is optimized to get the best SSIM metric values. While SSIM is (much) better than PSNR, it isn't perfect. psy-rd biases towards the energy of the source and will give, at higher values, a more subjectively looking better quality

There's also dynamic-rd but it needs vbv-bufsize and vbv-maxrate *and* you need to be hitting those for dynamic-rd to optimally do its thing

[benwaggoner]

Originally Posted by froggy1

There's also dynamic-rd but it needs vbv-bufsize and vbv-maxrate *and* you need to be hitting those for dynamic-rd to optimally do its thing

--dynamic-rd is really a speed/quality tradeoff option, orthogonal to the style of RD actually being applied. dynamic-rd changes the --rd parameter when the VBV buffer is hit, so a faster, lower quality setting can be used for easier sections of the video.

[benwaggoner]

Say, is anyone making Windows binaries with AVX-512 support somewhere? I wanted to do some tests.

[jlpsvk]

Originally Posted by benwaggoner

Say, is anyone making Windows binaries with AVX-512 support somewhere? I wanted to do some tests.

just use --asm avx512

[Magik Mark]

Originally Posted by benwaggoner

--dynamic-rd is really a speed/quality tradeoff option, orthogonal to the style of RD actually being applied. dynamic-rd changes the --rd parameter when the VBV buffer is hit, so a faster, lower quality setting can be used for easier sections of the video.

What values would you suggest for vbv buffer when encoding 1080p and 2160p in 2 pass. Maybe a guide or a table. Thanks alot


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[Blue_MiSfit]

If you're encoding for streaming, I'd start with maxrate = 1.1x - 1.5x bitrate and bufsize = 2x bitrate.

Else set them to the profile maximums

[Magik Mark]

Originally Posted by Blue_MiSfit

If you're encoding for streaming, I'd start with maxrate = 1.1x - 1.5x bitrate and bufsize = 2x bitrate.

Else set them to the profile maximums

Oh I see. Can you refer me to the table detailing max buffer for every profile? Thanks


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[l00t]

Originally Posted by benwaggoner

Say, is anyone making Windows binaries with AVX-512 support somewhere? I wanted to do some tests.

Unfortunately, according to my experiences, it won't do any good, because the CPU's clock speed will be significantly lower and will compensate the speed boost from using AVX512 (or at least this was the case for a Xeon Gold 6152).

[jlpsvk]

Originally Posted by l00t

Unfortunately, according to my experiences, it won't do any good, because the CPU's clock speed will be significantly lower and will compensate the speed boost from using AVX512 (or at least this was the case for a Xeon Gold 6152).

yeah... avx512 produces much more heat... so probably safety issue...

[LazyNcoder]

Hello guys,

Any good, accurate and easy way to convert h265 HDR bt2020 to SDR bt709 using Avisynth/Vapoursynth (maybe via Staxrip)?
Something like what madVR is doing, without all the troubles.

[redbtn]

Originally Posted by LazyNcoder

Hello guys,

Any good, accurate and easy way to convert h265 HDR bt2020 to SDR bt709 using Avisynth/Vapoursynth (maybe via Staxrip)?
Something like what madVR is doing, without all the troubles.

Easy, no. You can try HDR to SDR conversion, but you have to adjust settings to every movie.

[LazyNcoder]

Originally Posted by redbtn

Easy, no. You can try HDR to SDR conversion, but you have to adjust settings to every movie.

Eh, thanks?

Any tutorials/tools for doing that?
I can search I know. But you could save a lot of time being wasted for me or other people reading your reply. After all, that's why we are all here. Thank you

[redbtn]

Originally Posted by LazyNcoder

Any tutorials/tools for doing that?

I don't have any tutorials, but some links can help you.

http://forum.doom9.org/showthread.php?p=1847425

http://forum.doom9.org/showthread.php?p=1888974

http://forum.doom9.org/showthread.php?p=1880345

http://forum.doom9.org/showthread.php?p=1800667

[Atak_Snajpera]

Originally Posted by LazyNcoder

Hello guys,

Any good, accurate and easy way to convert h265 HDR bt2020 to SDR bt709 using Avisynth/Vapoursynth (maybe via Staxrip)?
Something like what madVR is doing, without all the troubles.

https://forum.doom9.org/showthread.p...84#post1893684

[Majorlag]

Originally Posted by Magik Mark

Oh I see. Can you refer me to the table detailing max buffer for every profile? Thanks


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For x264 look at https://en.wikipedia.org/wiki/Advanced_Video_Coding under Levels

For x265 look at https://en.wikipedia.org/wiki/High_E...y_Video_Coding or for a more detailed deep dive at https://en.wikipedia.org/wiki/High_E...ers_and_levels

For my encodes I use 1080p:--vbv-bufsize 20000 --vbv-maxrate 20000 and for 2160p:--vbv-bufsize 25000 --vbv-maxrate 25000, so that I make sure to meet DXVA requirements for some older finicky set top boxes.

[benwaggoner]

Originally Posted by Magik Mark

What values would you suggest for vbv buffer when encoding 1080p and 2160p in 2 pass. Maybe a guide or a table. Thanks alot


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By default I'll use the maximum values defined by the Profile, Tier, and Level. Wikipedia's HEVC article has a very nice table.

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[benwaggoner]

Originally Posted by LazyNcoder

Hello guys,

Any good, accurate and easy way to convert h265 HDR bt2020 to SDR bt709 using Avisynth/Vapoursynth (maybe via Staxrip)?
Something like what madVR is doing, without all the troubles.

There is no "accurate" way to do this. HDR and SDR masters are actually done as seperate creative passes, emphasizing different visual elements. They get approved seperately by the creatives before release.

If you want 709, best to start with the 709 source. There is almost no HDR content that isn't also available in SDR.

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