MeGUI - x264/XviD/lavc/Snow encoder with MP4/MKV/AVI output & audio

[LigH]

If you are not yet very experienced, only use {1-pass:CRF or 2-pass:bitrate}, speed preset, content tuning, and possibly playback device. If you like, make your own profile with these options.

3-pass encoding is not recommendable in general. It was an attempt to optimize very low bitrate encodings, but the results might look even more artifical than a 2-pass or CRF encoding, due to a more narrow quantization range. Nothing substitutes "enough bitrate".

[daemon_k]

Thank you for your reply.

There are three problems are not very clear. What I mean is:
1, "{1-pass: CRF or 2-pass: bitrate}" What does this mean?
Is not to be understood as: "1-pass: CRF" <=> "Targeting quality (Default: Quality = 23.0)" And "2-pass: bitrate" <=> "Targeting file size (Default: Bitrate = 1000)" ?
2, if this understanding is correct, then when using the 2-pass approach, based on your experience, to achieve different quality, you can set the bitrate roughly how much?
For example the following three scenarios:
A: canopus chqx Lossless (1440 * 1080i) -> Blu-ray
B: Blu-ray Re -> 1080
C: Other -> ipad
3, if you need to import "MeGUI-x264_generic_profiles_v85.zip"? These profiles and Megui 2341 compatible? Or is one of those that can be used in Megui2341?

Thank you again!

[Betsy25]

Zathor,

FYI x264 r2334 is now stable.

[Zathor]

Originally Posted by daemon_k

1, "{1-pass: CRF or 2-pass: bitrate}" What does this mean?
Is not to be understood as: "1-pass: CRF" <=> "Targeting quality (Default: Quality = 23.0)" And "2-pass: bitrate" <=> "Targeting file size (Default: Bitrate = 1000)" ?
2, if this understanding is correct, then when using the 2-pass approach, based on your experience, to achieve different quality, you can set the bitrate roughly how much?
3, if you need to import "MeGUI-x264_generic_profiles_v85.zip"? These profiles and Megui 2341 compatible? Or is one of those that can be used in Megui2341?

My opinion: Use bitrate only when you need to hit a specific file size. The bitrate will then be set automatically. Otherwise use the "quality" mode and choose different values there until you find your value.
Do not use the old profiles anymore. They are no supported.

Originally Posted by Betsy25

FYI x264 r2334 is now stable.

Thanks - updated.

[LigH]

@ daemon_k:

1) OK, a little more like pseudo-code: I meant that you should use only

{EITHER target quality OR target size} AND preset AND tuning [AND MAYBE playback device]

but you should not change any more advanced options unless you studied their meaning thoroughly. The mentioned basic options were well balanced (in relation to each other) by the developers with probably more experience than the average user.

[superhil]

just curious, how to reencode vfr video?
I always get audio out of sync when reencode using MeGUI
(video length is exactly same with original, but different fps)

Simple tools made by LoRd_muldeR works very fine (link)
What's basic difference between both of them?

---
edit:
---
I think I found the basic difference between those two,
LoRd_muldeR's tool using avs2yuv, while MeGUI using avs4x264mod for piping

I'm a newbie in encoding, could somebody please explain it?

Thank you very much

[DoctorM]

I noticed in some recent update DXVA's settings were changed to "--level 4.1 --vbv-bufsize 78125 --vbv-maxrate 62500".

Isn't that Level 4.2? Searching I can find no explanation for the change.

[detmek]

No, VBV values are correct for Level 4.1 High Profile.
Look here.
Also read the first line of text below the table.

[DoctorM]

So was the previous line of "--level 4.1" wrong or is the addition of the bufsize and maxrate a tweak to compensate for changes made in the x264 code?

[jq963152]

Originally Posted by DoctorM

So was the previous line of "--level 4.1" wrong or is the addition of the bufsize and maxrate a tweak to compensate for changes made in the x264 code?

You might want to read through the following thread:

http://forum.doom9.org/showthread.php?t=165627

[detmek]

--level parametar only limits refferent frames if those are not manualy specified. If you want fully compliant video stream you need to manualy add --vbv-maxrate and -vbv-bufsize.

[DoctorM]

So then you all are saying the old preset was wrong and anything previously encoded using that setting is not compliant.

I'd been using DXVA as a general setting since Level 4.1 is frequently considered compatible with more devices.
How is that effected by the new maxrate and bufsize? Are we talking more compatible?

[detmek]

I don't know what settings are used by old DXVA preset. But even without VBV settings those files should be DXVA compliant as VBV restrictions are very high. Consider that Blu-Ray uses --vbv-maxrate 40000 and --vbv-bufsize 30000 with average bitrate 20000-30000kbs. And people usually use lower average bitrate which, in most cases prevents spikes over 62500kbs.

Basically yes, new preset should be more compatible if old preset did not contain VBV restrictions.

[DoctorM]

Thanks. That does indeed clarify things.

Is it reasonable to believe that the DXVA setting (as that stand now) is a better 'General' setting than the Default preset (which does not have any restrictions or Level 4.1?

I've been doing encodings (mostly 720p) that I'm currently watching on a PC but would like to have future compatibility with standalone devices or 'smart' TVs. I'm aware that many of these devices do have a Level 4.1 restriction.

[SHaKOL]

Hi
does MeGUI encode 10-bit video? and would you add all the things in x264gui like encodeing 10-bit videos and such.

thanks in advance.

[LigH]

The simple way: You can exchange the tools\x264\x264.exe against a 10 bit version. But it will still receive YV12.

Handling higher bitdepths and finer chroma subsampling requires both manually editing the script and adding custom command line parameters. MeGUI will not (yet?) add these by checking a box.

[Zathor]

Please tell me what need to be changed and I may add it (without ETA)

[LigH]

A first step would be, similar to supporting both 32 and 64 bit architecture compiles of x264, also supporting both 8 and 10 bit channel depth compiles alternatively. There are many reports that the 10 bit channel bitdepth support already enhances compression efficiency, even with provided default YV12 video (YUV 4:2:0). Unfortunately, most consumer decoder chips may not support the AVC profile high10.

AviSynth 2.6x also supports finer chroma subsampling (e.g. YV16 or YV24). To feed x264 with such video, it will require the use of the parameters --input-csp and --output-csp, and will lead to even less compatible AVC profiles (high422, high444). And many plugins may not support these color spaces.

Possibly beyond capabilities of a script generating GUI may be the support of Deepcolor filters, they may require manual script editing...

[detmek]

Originally Posted by LigH

A first step would be, similar to supporting both 32 and 64 bit architecture compiles of x264, also supporting both 8 and 10 bit channel depth compiles alternatively. There are many reports that the 10 bit channel bitdepth support already enhances compression efficiency, even with provided default YV12 video (YUV 4:2:0). Unfortunately, most consumer decoder chips may not support the AVC profile high10.

AviSynth 2.6x also supports finer chroma subsampling (e.g. YV16 or YV24). To feed x264 with such video, it will require the use of the parameters --input-csp and --output-csp, and will lead to even less compatible AVC profiles (high422, high444). And many plugins may not support these color spaces.

Possibly beyond capabilities of a script generating GUI may be the support of Deepcolor filters, they may require manual script editing...

+1

Although most hardware decoders do not support 10-bit video or other color spaces there are a lot of people (like me) who use PC for watching videos on monitor or TV connected via HDMI.

10-bit support should be easy to add, just like x64 binaries and checkbox.

For other color spaces Avisynth should be updated to 2.6 and AVS Script Creator would require a checkbox (or checkbox + dropdown box) for ConvetToYVxx. Plus, input/ouput csp dropdown box in x264 configuration dialog.

[jq963152]

And also add the appropriate profiles to the AVC Profile dropdown list in the MeGUI x264 configuration dialog, namely: High 10 Profile (--profile high10) and High 4:2:2 Profile (--profile high422) and High 4:4:4 Predictive Profile (--profile high444).

And make sure to apply the correct VBV restrictions for those profiles.

As you already know, for --profile high the VBV restrictions are 1.25 times higher than those of --profile baseline / --profile main.

So:

For --profile high10 the VBV restrictions are 3 times higher than those of --profile baseline / --profile main.

And for --profile high422 and --profile high444 the VBV restrictions are 4 times higher than those of --profile baseline / --profile main.