MeGUI x264 presets.

[Shevek]

Originally Posted by BlockABoots

Hang on, i thought the higher the CRF value the lower the quality???

Originally Posted by Atak_Snajpera

what does 'lower value' mean in english then?

Lower CRF results in higher quality encode

i.e. CRF 16 will be better quality than CRF 23

If you hover over the Quality box in the config window you will see a tooltip with a very good explanation.

Unfortunately you cannot copy/paste from a tooltip otheriwse I'd repeat it here.

[LigH]

But you can easily quote from megui\Data\ContextHelp.xml:

Constant Ratefactor

Encode in Quality Based Variable Bit Rate mode, regardless of bit rate.

CRF targets a certain 'quality'. The idea is for crf n to give the same perceptual quality as qp n,
just in a smaller space. It is not extremely exact, but reasonably close (and will average out to be
accurate over a large number of videos). The arbitrary unit of measure for crf values is the "ratefactor".
CRF achieves this by reducing the quality of 'less important' frames. In this context, 'less important' means
frames in complex or high-motion scenes, where quality is either more expensive (in terms of bits)
or less visible, will have their quantizer increased. The bits saved in frames like these are redistributed
to frames where they will be more effective. CRF will take less time than a 2pass bitrate encode,
because the 'first pass' from a 2pass encode was skipped. On the other hand, it's impossible to predict
the bitrate a CRF encode will come out to (without actually performing the encode or a portion of it).
It's up to you to decide which rate-control mode is better for your circumstances.

Default: 23

Recommended:
The range 18-26 is probably where you will want to look at. If you need absolutely perfect quality
you could go down to 16, but it's probably not worth it. Around 19-21.5 is where a rip will look very good.
Higher resolution encoding can generally get away with higher crf values.

[TheProfosist]

For some reason the link sems to be dead for me. I know the archive is outdated for settings for x264 but i would still like it if possible.

EDIT: never mind the mirror worked

[Zathor]

Avoid using those profiles in MeGUI. A lot of the settings have changed and they will not be migrated anymore to the correct settings.

[greatdanton]

no more update for Megui?

[LigH]

Read the last reply by Zathor above your post again.

Use the basic "Preset" and "Tuning" options if you know less about the relations between the advanced x264 options that the developers of x264.

[greatdanton]

Originally Posted by LigH

Read the last reply by Zathor above your post again.

Use the basic "Preset" and "Tuning" options if you know less about the relations between the advanced x264 options that the developers of x264.

ok thanks but I can't find the advanced x264 options in this forum other than the officanl website of the x264 (http://mewiki.project357.com/wiki/X264_Settings#subme)

[LigH]

Understanding some of the advanced options in x264 may require having read and understood the MPEG4 Part 1, 2, and 10 specifications, as well as general video analysis and compression techniques. Most of that is technical stuff too heavy for the average user. Therefore, the x264 developers spent a lot of efforts into balancing the relations between presets and tunings to be useful in most cases. And in general you can trust the rule: Nothing is better than "enough" bitrate.

[greatdanton]

Originally Posted by LigH

Understanding some of the advanced options in x264 may require having read and understood the MPEG4 Part 1, 2, and 10 specifications, as well as general video analysis and compression techniques. Most of that is technical stuff too heavy for the average user. Therefore, the x264 developers spent a lot of efforts into balancing the relations between presets and tunings to be useful in most cases. And in general you can trust the rule: Nothing is better than "enough" bitrate.

ok thanks for reply
Do you mean that is enough for average user to encode in settings such as presets and tunings, high bitrate?

[LigH]

Yes. The x264 developers put severe efforts into condensing the complex relations between the many detail options to so few convenient and intuitive meta-options that average users can most probably get acceptable-to-great results with

• target bitrate or "quality level" (CRF value)
• (speed) preset
• (content) tuning
• maybe a few device compatibility options, if required (to be turned into a "device" meta-option some day; MeGUI already does that in its dialog...)

[Xor]

Hi thanks for presets.

Please i'am a newbye how to install presets in megui? I tryed to copy in related folder "c:\MeGUI_2356_x86\allprofiles\x264\" but not work. Installed preset not appear.

Thanks

[LigH]

Do not try to use obsolete presets which are not supported by the current MeGUI version anymore.

[rapscallion]

Well, in case he wants to (I still use the 720p/1080p presets and they work fine)

>File>Import Presets....then select the Zip file presets.

[Zathor]

And as an additional information:
Every setting which has changed internally in the last years will not be applied at all when importing these old presets. So you will definitively end with something between the original preset and the recent MeGUI default values as a lot has been changed internally over those years.

[rapscallion]

I didn't realize that !

So, in the "Input" screen what do you enter in the Encoder Settings dialog box (where the presets are/were displayed)?

If I delete all the x264 preset options/profiles, then x264: "Scratchpad" remains. Is that what it should be?

[Zathor]

It is up to you. But I would not import those old presets and instead create a few new ones depending on what you need / encode for.

I have created a few presets for my encodings like several Bluray presets and also a few WDTV ones. All of my presets have crf (~18) & very slow setting & no/film tuning. At the end you can say I change only settings on the first page and do not bother with the other settings.

[rapscallion]

The only one I've been using for a long time is the x264:Blu-ray 1080p/720p. On build #2487

First page (show advanced settings) I select "Automated 2 pass", "Target Playback Device: Bluray", "Tuning": Film
"Bitrate": whatever I get in the bitrate calculator for the particular BD I'm re-encoding (I usually reduce a full BD-50 down to BD-25, film only) And, like you, "Preset": slow

If I select "scratchpad", and apply the same setting as above, the command line is virtually identical.

BTW, I wouldn't know the first thing on creating a preset. I don't see any option in any of the "Advanced Settings" for selecting CRF 18. But, then again, I'm using VBR so Constant Rate Factor wouldn't apply, I believe?

Edit: I have been happy with the results and always seem to get a result almost identical/transparent to the original BD.

Custom Command line on the Misc page:

--level 4.1 --bframes 3 --ref 4 --slices 4 --aud 
-nal-hrd vbr --b-pyramid strict --keyint 24 --min-keyint 2 
-vbv-bufsize 30000 --vbv-maxrate 40000 --weightp 0 
-colorprim "bt709" --transfer "bt709" --colormatrix "bt709"

Main page settings:

[ramsmart]

how to get megui x265 presets ??????

[LigH]

Just as collectibles ... or for a specific purpose (e.g. being compatible to specific playback devices)?

[ramsmart]

Originally Posted by LigH

Just as collectibles ... or for a specific purpose (e.g. being compatible to specific playback devices)?

Just as collectibles