If I rip with crf, how could I know the compressibility then make judgment?

[xuguang_he]

If I rip with crf, how could I know the compressibility then make judgment?

In the past, I always use crf 19.0 and it normally will give me reasonable size with good video quality. But somtimes, it sure give a size much bigger. So, is there any way to know the compressibility of the source DVD? And suppose I know it then, how could I set the crf number precisely?

If the source is very uncompressible, how could I make it compressible? By filter? (MCTemporalDenoise?)
If the source is very compressible, then what number should I us for crf? (17.5? 18.0?)

[manono]

And suppose I know it then, how could I set the crf number precisely?

You want to set the CRF to make the size you want? You can't. Set the bitrate instead and run two passes for your size. With CRF encoding the sizes might be all over the place. With 2-pass bitrate encoding the quality might be all over the place.

So, is there any way to know the compressibility of the source DVD?

You could run a sort of compression test first to judge its compressibility. For example, adding this to your AviSynth script:

SelectRangeEvery(280,14)

will encode 14 frames out of every 280, or 5% of the full movie. From that you can get a general idea of the compressibility of the full movie.

If the source is very uncompressible, how could I make it compressible? By filter?

Yes, by filter.

If the source is very compressible, then what number should I us for crf? (17.5? 18.0?)

Only you can answer that question.

[xuguang_he]

I've tried to use filter, but this seems to occur error.

SetMemoryMax(512)
SetMTMode(3)
LoadPlugin("D:\Program Files\Megui\tools\dgindex\DGDecode.dll")
DGDecode_mpeg2source("E:\yazhi\s\Tender.Is.the.Night.1962.DVDRip.x264.AC3.d2v")
Import("D:\Program Files\Megui\tools\avisynth_plugin\MCTemporalDenoise.v1.4.20.avs")
MT("""
MCTemporalDenoise(settings="very low",sigma=1,chroma=true,enhance=false,sharp=false,GPU=false)
""",threads=0,overlap=8)
SetMTMode(2)

I've put my script this way, but the MeGUI error:
"There is no function named MT"

I've already install the Avisynth 2.6, and I've replace the avisynth.dll downloaded from the doom9 page. And I haven't found any "MT.dll" in that zip pack.

[jman98]

Remove this from your script. This is the 6th line in what you wrote.

MT("""

That will fix the problem.

Also, just so you know, it's not necessary to pretend to be a woman to get help here. The odds of a woman being interested in video enough to use AviSynth are very very low. I am talking about that picture you have under your name.

[xuguang_he]

I'm not "pretend" to be a woman or anything. And that woman is not some ordinary people, she is JOAN FONTAINE for god's sake.
And this forum named "videohelp", isn't it? Am I get it wrong or sth? Isn't it suppose to be a place where to pick out questions and post?

Anyway, glad to meet your guy say this words.