Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Video Encoding > High Efficiency Video Coding (HEVC)

Reply
 
Thread Tools Search this Thread Display Modes
Old 16th July 2021, 20:52   #21  |  Link
tonemapped
Video Fanatic
 
tonemapped's Avatar
 
Join Date: Jul 2021
Location: Surrey
Posts: 72
Quote:
Originally Posted by Boulder View Post
Since your x265 don't have "regular" settings (--tune grain or --no-cutree are not very common), I cannot say anything about those QPs. They are rather high but that's probably because both encodes disable the cu-tree.

How about with something like this: --preset slower --deblock -1:-1 --no-sao --merange 58 --rskip 2 --rskip-edge-threshold 2 --rd-refine --max-merge 2 --ref 4 --bframes 10 --limit-refs 0 ?
Happy to try that out, but it'll be 2-pass 5mbps to match the other encodes for comparison. I should have perhaps reserved two or three posts so I could add them all in one continuous go, or maybe create a new thread with five post reserved due to the post image limit. Not sure if moderators would be happy with that.

One of the two x265 encodes is default --tune grain (with a couple of modifications such as deblock -3/-3, but nothing major) and the other is Ben Waggoner's suggestion higher up the thread.

Last edited by tonemapped; 16th July 2021 at 21:12.
tonemapped is offline   Reply With Quote
Old 17th July 2021, 02:27   #22  |  Link
tonemapped
Video Fanatic
 
tonemapped's Avatar
 
Join Date: Jul 2021
Location: Surrey
Posts: 72
Quote:
Originally Posted by Boulder View Post
Since your x265 don't have "regular" settings (--tune grain or --no-cutree are not very common), I cannot say anything about those QPs. They are rather high but that's probably because both encodes disable the cu-tree.

How about with something like this: --preset slower --deblock -1:-1 --no-sao --merange 58 --rskip 2 --rskip-edge-threshold 2 --rd-refine --max-merge 2 --ref 4 --bframes 10 --limit-refs 0 ?
Done. Added to the bottom of http://forum.doom9.net/showthread.ph...62#post1947762

For just over four hours of encoding time for four minutes of video, the results were not as good as hoped. The video seems to 'smear' grain into other grain.
tonemapped is offline   Reply With Quote
Old 17th July 2021, 10:08   #23  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Finland
Posts: 5,186
The difference between x264 and x265 is that the former creates blocking and the latter blurs when it's bitrate-starved and usually blocking doesn't seem as distracting. The QPs look quite high so the encode definitely is lacking bits. The encoding process is definitely very slow, so probably you're better off with x264 anyway.
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 17th July 2021, 17:50   #24  |  Link
tonemapped
Video Fanatic
 
tonemapped's Avatar
 
Join Date: Jul 2021
Location: Surrey
Posts: 72
Quote:
Originally Posted by Boulder View Post
The difference between x264 and x265 is that the former creates blocking and the latter blurs when it's bitrate-starved and usually blocking doesn't seem as distracting. The QPs look quite high so the encode definitely is lacking bits. The encoding process is definitely very slow, so probably you're better off with x264 anyway.
That may be the case, but to my eyes some of the hardware-encoded (Intel) look better than software-encoded. This shouldn't be the case. Even with x264, it is possible to produce a visually appealing grainy encode with a relatively low bitrate (e.g. 3500kbps @ 720p). Is it perfect? No. But that's not the point.

x265 is meant to bring improvements in size:compression/efficiency, amongst other features, and it's mature enough by now that grain retention should match that of x264's. x265 seems good for content with very, very light grain and content without grain. This is the most bizarre part to me. Even the --grain preset produces poor results.

Again, the entire point of doing a 2-pass encode at 5mbps is to compare different codecs and encoding methods at the same bitrate using the same source. If the newest one loses to hardware encoding and its predecessor, that shows a problem. I do use crf for encoding the vast majority of content for storage, but that's not the point of this test.

Last edited by tonemapped; 17th July 2021 at 18:01.
tonemapped is offline   Reply With Quote
Old 17th July 2021, 20:51   #25  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Finland
Posts: 5,186
Unfortunately x265 is not tuned for grain retention. We have fought that issue for years but the devs have never considered it a high priority thing. The tunings are not revised at all, and the first three AQ modes were mostly just ported directly from x264 and then left as they are.

The biggest issue with x265 is is that the most capable people left a long time ago and even patch validation has had issues with features getting worse with development.
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 17th July 2021, 22:36   #26  |  Link
tonemapped
Video Fanatic
 
tonemapped's Avatar
 
Join Date: Jul 2021
Location: Surrey
Posts: 72
Quote:
Originally Posted by Boulder View Post
Unfortunately x265 is not tuned for grain retention. We have fought that issue for years but the devs have never considered it a high priority thing. The tunings are not revised at all, and the first three AQ modes were mostly just ported directly from x264 and then left as they are.

The biggest issue with x265 is is that the most capable people left a long time ago and even patch validation has had issues with features getting worse with development.
Grain retention is great at ~9mbps, or even light grain at 3.5mbps for 1080p content. It's just high grain (as with the example) for low bitrate.

For example, I recently encoded a few episodes of Charmed from Blu-ray using CRF 21 with only a few changes (no-sao, etc.) and the result is great and only ~1.2GB per episode instead of ~7GB. A little bit of quality is lost in dark areas, but that's less of a concern for me. Overall, I would say it's 90% of the quality for 1/7 of the size. x264 would have severely struggled to output a reasonable file with the same bitrate/CRF constraints, so there's definitely a use for it.
tonemapped is offline   Reply With Quote
Old 18th July 2021, 19:40   #27  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Finland
Posts: 5,186
I still wouldn't call that grain, it's much more like quantization noise to me. That is more difficult to encode in a nice way than true film grain as it gets ugly quite easily like you have proven here.
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 23rd July 2021, 22:04   #28  |  Link
Sulik
Registered User
 
Join Date: Jan 2002
Location: San Jose, CA
Posts: 216
Why no B-frames in the NVENC and QSV encodes ?
Sulik is offline   Reply With Quote
Old 23rd July 2021, 22:30   #29  |  Link
tonemapped
Video Fanatic
 
tonemapped's Avatar
 
Join Date: Jul 2021
Location: Surrey
Posts: 72
Quote:
Originally Posted by Sulik View Post
Why no B-frames in the NVENC and QSV encodes ?
Not entirely sure. There was a message about b-frames not being supported on 'Gen 9.5' hardware (UHD 605, API 1.3x). On NVENC, I have no idea why b-frames weren't used. Either way, NVENC still produced some of the worst with over 20 tests of the same clip, compared to even QSV.
tonemapped is offline   Reply With Quote
Old 24th July 2021, 00:05   #30  |  Link
benwaggoner
Moderator
 
Join Date: Jan 2006
Location: Portland, OR
Posts: 3,977
IIIRC NVidia added support for B-frames with the RTX series.
__________________
Ben Waggoner
Principal Video Specialist, Amazon Prime Video

My Compression Book
benwaggoner is offline   Reply With Quote
Old 24th July 2021, 03:02   #31  |  Link
tonemapped
Video Fanatic
 
tonemapped's Avatar
 
Join Date: Jul 2021
Location: Surrey
Posts: 72
Quote:
Originally Posted by benwaggoner View Post
IIIRC NVidia added support for B-frames with the RTX series.
That was done on a Turing card, so should have support. I must have made a mistake. The rest of the encodes are of more importance, as NVENC smears grain/noise.
tonemapped is offline   Reply With Quote
Reply

Tags
grain, noise, nvenc, qsv, x265

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 03:35.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.