Quote:
Originally Posted by benwaggoner
That's not surprising. Something like --preset slower would probably be better, but there's only so much threading that can be usefully done in a single instance, and Blu-ray restrictions reduce even that (b-frames can encode in parallel, but BD only allows 2 consecutive). Increasing -F will help, but high values can cause rate control issues.
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Yes... With slower I might get something more but still, it's still acceptable.
Quote:
Originally Posted by excellentswordfight
I see around 70-80% utilization on dual Xeon E5-2680 v3 (48t) systems for 2160p content using preset slow. Imo that is a very reasonable ammount of multithread performance.
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Yes, it kinda is.
Quote:
Originally Posted by jlpsvk
could you post your uhd bd compatible command line?
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Sure.
UHD HDR10 BD50:
Code:
x265.exe --y4m - --dither --preset medium --level 5.1 --tune fastdecode --no-high-tier --ref 4 --profile main10 --bitrate 75000 --deblock -1:-1 --hdr-opt --hrd --min-luma 64 --max-luma 940 --chromaloc 2 --range limited --videoformat component --colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc --master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,0.0050)" --max-cll 1000,400 --overscan show --no-open-gop --min-keyint 1 --keyint 24 --repeat-headers --rd 3 --vbv-maxrate 75000 --vbv-bufsize 75000 --asm=avx2 --wpp -o "H:\raw_video.hevc"
I know that some of you might be screaming "Ah!!" to that "brutal" clipping, but the uncompressed 16bit stream that x265 is gonna encode has already been brought in Tv Range with a proper LUT that tries to avoid to clip too much, so that's just for "safety reasons", especially 'cause otherwise QC refuses it, even if there's just a single scene in the video that is out of range. No, they don't stare at the video-scope all the time; such a process is automated by a machine that checks the file 1:1 and reports details about luma, chroma, whether there are freeze-frames, blocking of whatever type and so on. Sometimes it fails and it is spot-checked by a human, but still, they refuse the content if it's out of range.
Still, using --preset slow might help a bit, but I would have to specify parameters myself, especially 'cause I'm not using --uhd-bd and I would end up by limiting myself anyway.
Increasing --ref from 4 to 6 might also help.
As to the 75Mbit/s, the specs require the bitrate to stay below 82Mbit/s, but 75Mbit/s plus a bit of oscillation up and down and audio tracks is gonna be fine.