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Old 6th August 2018, 18:16   #6265  |  Link
Dclose
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Join Date: Aug 2014
Posts: 50
Quote:
Originally Posted by K.i.N.G View Post
I really like x265 but I seem to be unable to get rid of linear smearing/stretching artifacts when there are fast moving objects in a scene.
Is there a specific parameter targeted at improving this, without increasing the bit rate in other areas (those are fine)?

My settings are:
--crf 17 --preset veryslow --profile main10 --level-idc 5 --output-depth 10 --psy-rdoq 4 --aq-mode 3 --qg-size 64 --qcomp 0.7 --subme 5 --master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(40000000,50)" --colorprim bt2020 --colormatrix bt2020nc --transfer smpte2084 --max-cll "457,179" --hdr --hdr-opt --deblock -1:-1 --no-sao --no-strong-intra-smoothing

example:
1) imo, if you care about things that move, (and picture quality in general), you have to use sub-motion pixel subme 7. 5 is good, and is as low as I ever set that even on files I'm trying to finish fast, but 5 is easily visually inferior to 7 imo. 7 of course takes longer to encode though.

2) You have qg-size 64. I almost never encode 4k lately, but for 1080, my coding, quant, and tree unit settings are a low of 8 and high of 32, and Max Intra/Inter are maxed. 64 didn't look as sharp, and didn't have any noticeable advantages, even during a fairly recent test I did of them.

3) AQ mode. "auto" (mode 2?) was too inconsistent in quality for me. A main thing is faces tend to lack quality. And faces tend to be the main place on the screen to look at. If mode 3 is the "experimental/dark area" mode, the file sizes were too inconsistent for me. That mode tended to throw a lot of bitrate at the file and too often made the sizes huge. I use normal mode now, for consistency of video quality and filesize. I haven't retested the others in a year or so, so maybe they have improved.

4) With later releases of x265, I stopped messing with the q-comp type of settings. I did a big test on them again a couple months ago and found the default settings are very good.

5) -1/-1 is a lot of deblocking. I use -5/-4 even on encodes most people would probably consider very low bitrate. I'm usually around crf 21-24 though, not 17, so maybe deblocking has less effect at 17 anyway. At crf 17, I would think some obvious setting is wrong somewhere for it to not look great.
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