Question about ZarxGUI

[GundalianSoul]

I was wondering why it has settings for placebo/very slow/slow/fast..etc
Will it affect the video if you set it to very fast? (I usually have it on very slow).

Sorry if this isnt the right board to ask this

[BasharOfTheAges]

The presets are related to quality of output and size of output. I've found "very slow" to be a good default in most cases.

The text box at the bottom of the GUI actually shows you the exact parameters being used for each preset if you're interested in learning about what they actually do.

[Mister Hatt]

Once again people who don't know are answering, this sure happens a lot. The presets you're asking about are not ZarxGUI, they are directly from x264. They are designed to change the default options used so that for a chosen encode speed/quality you are required to do less tweaking. Alongside the presets are tune options, which further optimise default settings to tweak towards improving how your specific content is handled. Good options for non-grainy anime would be --preset veryslow --tune animation at CRF 18. The idea is to make it easier to configure in commandline, so IMO not really needed in whatever crappy GUI people use.

[BasharOfTheAges]

Explain how what I wrote was contradicted in any way by what you wrote. I'm curious, because I went out of my way to be extremely vague and only as helpful as the OP seemed to need for the level of question answered.

[Mister Hatt]

Oh it wasn't contradicted or wrong, it was just misleading IMO. You made it sound like it was a ZarxGUI thing rather than x264 itself. Furthermore, if ZarxGUI does as I think it does, then the string at the bottom of the UI would only have the same preset stuff anyway which is of no help at all to the OP as he would still have no idea what they actually do.

[BasharOfTheAges]

The implication I guess I failed to make was that the actual string at the bottom told you exactly what it did, so you could actually go out and do research if you really wanted to know the details. Not to be snarky or anything, just as a matter of fact. I figured you of all people here would appreciate explaining jargon with more jargon.

[TheRyuu]

Each preset as you can probably guess relates to speed vs. quality.

Generally speaking the slower the preset you use (placebo being the slowest) the more quality you can get at the same bitrate.

The rule with the presets is pretty simple, choose the slowest one you can stand.

For some behind the scenes action, this is what x264 is doing with each preset:

Code: Select all

      --preset                Use a preset to select encoding settings [medium]
                                  Overridden by user settings.
                                  - ultrafast:
                                    --no-8x8dct --aq-mode 0 --b-adapt 0
                                    --bframes 0 --no-cabac --no-deblock
                                    --no-mbtree --me dia --no-mixed-refs
                                    --partitions none --rc-lookahead 0 --ref 1
                                    --scenecut 0 --subme 0 --trellis 0
                                    --no-weightb --weightp 0
                                  - superfast:
                                    --no-mbtree --me dia --no-mixed-refs
                                    --partitions i8x8,i4x4 --rc-lookahead 0
                                    --ref 1 --subme 1 --trellis 0 --weightp 0
                                  - veryfast:
                                    --no-mixed-refs --rc-lookahead 10
                                    --ref 1 --subme 2 --trellis 0 --weightp 0
                                  - faster:
                                    --no-mixed-refs --rc-lookahead 20
                                    --ref 2 --subme 4 --weightp 1
                                  - fast:
                                    --rc-lookahead 30 --ref 2 --subme 6
                                  - medium:
                                    Default settings apply.
                                  - slow:
                                    --b-adapt 2 --direct auto --me umh
                                    --rc-lookahead 50 --ref 5 --subme 8
                                  - slower:
                                    --b-adapt 2 --direct auto --me umh
                                    --partitions all --rc-lookahead 60
                                    --ref 8 --subme 9 --trellis 2
                                  - veryslow:
                                    --b-adapt 2 --bframes 8 --direct auto
                                    --me umh --merange 24 --partitions all
                                    --ref 16 --subme 10 --trellis 2
                                    --rc-lookahead 60
                                  - placebo:
                                    --bframes 16 --b-adapt 2 --direct auto
                                    --slow-firstpass --no-fast-pskip
                                    --me tesa --merange 24 --partitions all
                                    --rc-lookahead 60 --ref 16 --subme 10
                                    --trellis 2